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3274 lines
80 KiB
3274 lines
80 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Driver core for serial ports |
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* |
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* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. |
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* |
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* Copyright 1999 ARM Limited |
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* Copyright (C) 2000-2001 Deep Blue Solutions Ltd. |
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*/ |
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#include <linux/module.h> |
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#include <linux/tty.h> |
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#include <linux/tty_flip.h> |
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#include <linux/slab.h> |
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#include <linux/sched/signal.h> |
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#include <linux/init.h> |
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#include <linux/console.h> |
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#include <linux/gpio/consumer.h> |
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#include <linux/of.h> |
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#include <linux/proc_fs.h> |
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#include <linux/seq_file.h> |
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#include <linux/device.h> |
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#include <linux/serial.h> /* for serial_state and serial_icounter_struct */ |
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#include <linux/serial_core.h> |
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#include <linux/sysrq.h> |
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#include <linux/delay.h> |
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#include <linux/mutex.h> |
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#include <linux/security.h> |
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|
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#include <linux/irq.h> |
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#include <linux/uaccess.h> |
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|
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/* |
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* This is used to lock changes in serial line configuration. |
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*/ |
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static DEFINE_MUTEX(port_mutex); |
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|
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/* |
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* lockdep: port->lock is initialized in two places, but we |
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* want only one lock-class: |
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*/ |
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static struct lock_class_key port_lock_key; |
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|
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#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) |
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|
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static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, |
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struct ktermios *old_termios); |
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static void uart_wait_until_sent(struct tty_struct *tty, int timeout); |
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static void uart_change_pm(struct uart_state *state, |
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enum uart_pm_state pm_state); |
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|
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static void uart_port_shutdown(struct tty_port *port); |
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|
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static int uart_dcd_enabled(struct uart_port *uport) |
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{ |
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return !!(uport->status & UPSTAT_DCD_ENABLE); |
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} |
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|
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static inline struct uart_port *uart_port_ref(struct uart_state *state) |
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{ |
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if (atomic_add_unless(&state->refcount, 1, 0)) |
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return state->uart_port; |
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return NULL; |
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} |
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|
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static inline void uart_port_deref(struct uart_port *uport) |
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{ |
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if (atomic_dec_and_test(&uport->state->refcount)) |
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wake_up(&uport->state->remove_wait); |
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} |
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|
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#define uart_port_lock(state, flags) \ |
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({ \ |
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struct uart_port *__uport = uart_port_ref(state); \ |
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if (__uport) \ |
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spin_lock_irqsave(&__uport->lock, flags); \ |
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__uport; \ |
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}) |
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|
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#define uart_port_unlock(uport, flags) \ |
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({ \ |
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struct uart_port *__uport = uport; \ |
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if (__uport) { \ |
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spin_unlock_irqrestore(&__uport->lock, flags); \ |
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uart_port_deref(__uport); \ |
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} \ |
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}) |
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|
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static inline struct uart_port *uart_port_check(struct uart_state *state) |
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{ |
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lockdep_assert_held(&state->port.mutex); |
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return state->uart_port; |
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} |
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|
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/* |
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* This routine is used by the interrupt handler to schedule processing in |
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* the software interrupt portion of the driver. |
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*/ |
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void uart_write_wakeup(struct uart_port *port) |
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{ |
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struct uart_state *state = port->state; |
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/* |
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* This means you called this function _after_ the port was |
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* closed. No cookie for you. |
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*/ |
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BUG_ON(!state); |
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tty_port_tty_wakeup(&state->port); |
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} |
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|
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static void uart_stop(struct tty_struct *tty) |
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{ |
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struct uart_state *state = tty->driver_data; |
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struct uart_port *port; |
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unsigned long flags; |
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|
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port = uart_port_lock(state, flags); |
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if (port) |
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port->ops->stop_tx(port); |
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uart_port_unlock(port, flags); |
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} |
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|
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static void __uart_start(struct tty_struct *tty) |
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{ |
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struct uart_state *state = tty->driver_data; |
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struct uart_port *port = state->uart_port; |
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|
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if (port && !uart_tx_stopped(port)) |
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port->ops->start_tx(port); |
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} |
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|
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static void uart_start(struct tty_struct *tty) |
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{ |
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struct uart_state *state = tty->driver_data; |
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struct uart_port *port; |
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unsigned long flags; |
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|
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port = uart_port_lock(state, flags); |
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__uart_start(tty); |
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uart_port_unlock(port, flags); |
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} |
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|
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static void |
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uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) |
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{ |
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unsigned long flags; |
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unsigned int old; |
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|
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spin_lock_irqsave(&port->lock, flags); |
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old = port->mctrl; |
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port->mctrl = (old & ~clear) | set; |
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if (old != port->mctrl) |
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port->ops->set_mctrl(port, port->mctrl); |
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spin_unlock_irqrestore(&port->lock, flags); |
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} |
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|
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#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0) |
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#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear) |
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|
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static void uart_port_dtr_rts(struct uart_port *uport, int raise) |
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{ |
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int rs485_on = uport->rs485_config && |
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(uport->rs485.flags & SER_RS485_ENABLED); |
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int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND); |
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|
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if (raise) { |
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if (rs485_on && !RTS_after_send) { |
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uart_set_mctrl(uport, TIOCM_DTR); |
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uart_clear_mctrl(uport, TIOCM_RTS); |
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} else { |
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uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); |
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} |
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} else { |
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unsigned int clear = TIOCM_DTR; |
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|
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clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0; |
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uart_clear_mctrl(uport, clear); |
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} |
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} |
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|
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/* |
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* Startup the port. This will be called once per open. All calls |
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* will be serialised by the per-port mutex. |
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*/ |
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static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, |
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int init_hw) |
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{ |
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struct uart_port *uport = uart_port_check(state); |
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unsigned long page; |
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unsigned long flags = 0; |
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int retval = 0; |
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|
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if (uport->type == PORT_UNKNOWN) |
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return 1; |
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|
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/* |
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* Make sure the device is in D0 state. |
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*/ |
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uart_change_pm(state, UART_PM_STATE_ON); |
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|
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/* |
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* Initialise and allocate the transmit and temporary |
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* buffer. |
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*/ |
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page = get_zeroed_page(GFP_KERNEL); |
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if (!page) |
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return -ENOMEM; |
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|
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uart_port_lock(state, flags); |
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if (!state->xmit.buf) { |
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state->xmit.buf = (unsigned char *) page; |
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uart_circ_clear(&state->xmit); |
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uart_port_unlock(uport, flags); |
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} else { |
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uart_port_unlock(uport, flags); |
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/* |
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* Do not free() the page under the port lock, see |
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* uart_shutdown(). |
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*/ |
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free_page(page); |
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} |
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|
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retval = uport->ops->startup(uport); |
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if (retval == 0) { |
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if (uart_console(uport) && uport->cons->cflag) { |
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tty->termios.c_cflag = uport->cons->cflag; |
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uport->cons->cflag = 0; |
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} |
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/* |
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* Initialise the hardware port settings. |
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*/ |
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uart_change_speed(tty, state, NULL); |
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|
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/* |
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* Setup the RTS and DTR signals once the |
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* port is open and ready to respond. |
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*/ |
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if (init_hw && C_BAUD(tty)) |
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uart_port_dtr_rts(uport, 1); |
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} |
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|
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/* |
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* This is to allow setserial on this port. People may want to set |
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* port/irq/type and then reconfigure the port properly if it failed |
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* now. |
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*/ |
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if (retval && capable(CAP_SYS_ADMIN)) |
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return 1; |
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|
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return retval; |
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} |
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|
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static int uart_startup(struct tty_struct *tty, struct uart_state *state, |
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int init_hw) |
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{ |
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struct tty_port *port = &state->port; |
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int retval; |
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|
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if (tty_port_initialized(port)) |
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return 0; |
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|
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retval = uart_port_startup(tty, state, init_hw); |
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if (retval) |
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set_bit(TTY_IO_ERROR, &tty->flags); |
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|
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return retval; |
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} |
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|
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/* |
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* This routine will shutdown a serial port; interrupts are disabled, and |
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* DTR is dropped if the hangup on close termio flag is on. Calls to |
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* uart_shutdown are serialised by the per-port semaphore. |
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* |
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* uport == NULL if uart_port has already been removed |
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*/ |
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static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) |
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{ |
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struct uart_port *uport = uart_port_check(state); |
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struct tty_port *port = &state->port; |
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unsigned long flags = 0; |
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char *xmit_buf = NULL; |
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|
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/* |
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* Set the TTY IO error marker |
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*/ |
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if (tty) |
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set_bit(TTY_IO_ERROR, &tty->flags); |
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|
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if (tty_port_initialized(port)) { |
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tty_port_set_initialized(port, 0); |
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|
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/* |
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* Turn off DTR and RTS early. |
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*/ |
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if (uport && uart_console(uport) && tty) |
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uport->cons->cflag = tty->termios.c_cflag; |
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|
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if (!tty || C_HUPCL(tty)) |
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uart_port_dtr_rts(uport, 0); |
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|
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uart_port_shutdown(port); |
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} |
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/* |
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* It's possible for shutdown to be called after suspend if we get |
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* a DCD drop (hangup) at just the right time. Clear suspended bit so |
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* we don't try to resume a port that has been shutdown. |
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*/ |
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tty_port_set_suspended(port, 0); |
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|
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/* |
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* Do not free() the transmit buffer page under the port lock since |
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* this can create various circular locking scenarios. For instance, |
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* console driver may need to allocate/free a debug object, which |
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* can endup in printk() recursion. |
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*/ |
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uart_port_lock(state, flags); |
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xmit_buf = state->xmit.buf; |
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state->xmit.buf = NULL; |
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uart_port_unlock(uport, flags); |
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if (xmit_buf) |
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free_page((unsigned long)xmit_buf); |
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} |
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|
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/** |
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* uart_update_timeout - update per-port FIFO timeout. |
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* @port: uart_port structure describing the port |
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* @cflag: termios cflag value |
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* @baud: speed of the port |
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* |
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* Set the port FIFO timeout value. The @cflag value should |
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* reflect the actual hardware settings. |
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*/ |
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void |
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uart_update_timeout(struct uart_port *port, unsigned int cflag, |
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unsigned int baud) |
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{ |
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unsigned int bits; |
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|
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/* byte size and parity */ |
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switch (cflag & CSIZE) { |
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case CS5: |
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bits = 7; |
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break; |
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case CS6: |
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bits = 8; |
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break; |
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case CS7: |
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bits = 9; |
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break; |
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default: |
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bits = 10; |
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break; /* CS8 */ |
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} |
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|
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if (cflag & CSTOPB) |
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bits++; |
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if (cflag & PARENB) |
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bits++; |
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|
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/* |
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* The total number of bits to be transmitted in the fifo. |
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*/ |
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bits = bits * port->fifosize; |
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|
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/* |
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* Figure the timeout to send the above number of bits. |
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* Add .02 seconds of slop |
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*/ |
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port->timeout = (HZ * bits) / baud + HZ/50; |
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} |
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|
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EXPORT_SYMBOL(uart_update_timeout); |
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|
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/** |
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* uart_get_baud_rate - return baud rate for a particular port |
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* @port: uart_port structure describing the port in question. |
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* @termios: desired termios settings. |
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* @old: old termios (or NULL) |
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* @min: minimum acceptable baud rate |
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* @max: maximum acceptable baud rate |
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* |
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* Decode the termios structure into a numeric baud rate, |
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* taking account of the magic 38400 baud rate (with spd_* |
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* flags), and mapping the %B0 rate to 9600 baud. |
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* |
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* If the new baud rate is invalid, try the old termios setting. |
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* If it's still invalid, we try 9600 baud. |
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* |
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* Update the @termios structure to reflect the baud rate |
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* we're actually going to be using. Don't do this for the case |
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* where B0 is requested ("hang up"). |
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*/ |
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unsigned int |
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uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, |
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struct ktermios *old, unsigned int min, unsigned int max) |
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{ |
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unsigned int try; |
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unsigned int baud; |
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unsigned int altbaud; |
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int hung_up = 0; |
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upf_t flags = port->flags & UPF_SPD_MASK; |
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|
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switch (flags) { |
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case UPF_SPD_HI: |
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altbaud = 57600; |
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break; |
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case UPF_SPD_VHI: |
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altbaud = 115200; |
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break; |
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case UPF_SPD_SHI: |
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altbaud = 230400; |
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break; |
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case UPF_SPD_WARP: |
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altbaud = 460800; |
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break; |
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default: |
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altbaud = 38400; |
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break; |
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} |
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|
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for (try = 0; try < 2; try++) { |
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baud = tty_termios_baud_rate(termios); |
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|
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/* |
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* The spd_hi, spd_vhi, spd_shi, spd_warp kludge... |
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* Die! Die! Die! |
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*/ |
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if (try == 0 && baud == 38400) |
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baud = altbaud; |
|
|
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/* |
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* Special case: B0 rate. |
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*/ |
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if (baud == 0) { |
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hung_up = 1; |
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baud = 9600; |
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} |
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|
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if (baud >= min && baud <= max) |
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return baud; |
|
|
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/* |
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* Oops, the quotient was zero. Try again with |
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* the old baud rate if possible. |
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*/ |
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termios->c_cflag &= ~CBAUD; |
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if (old) { |
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baud = tty_termios_baud_rate(old); |
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if (!hung_up) |
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tty_termios_encode_baud_rate(termios, |
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baud, baud); |
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old = NULL; |
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continue; |
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} |
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|
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/* |
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* As a last resort, if the range cannot be met then clip to |
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* the nearest chip supported rate. |
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*/ |
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if (!hung_up) { |
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if (baud <= min) |
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tty_termios_encode_baud_rate(termios, |
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min + 1, min + 1); |
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else |
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tty_termios_encode_baud_rate(termios, |
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max - 1, max - 1); |
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} |
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} |
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/* Should never happen */ |
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WARN_ON(1); |
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return 0; |
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} |
|
|
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EXPORT_SYMBOL(uart_get_baud_rate); |
|
|
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/** |
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* uart_get_divisor - return uart clock divisor |
|
* @port: uart_port structure describing the port. |
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* @baud: desired baud rate |
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* |
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* Calculate the uart clock divisor for the port. |
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*/ |
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unsigned int |
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uart_get_divisor(struct uart_port *port, unsigned int baud) |
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{ |
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unsigned int quot; |
|
|
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/* |
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* Old custom speed handling. |
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*/ |
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if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) |
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quot = port->custom_divisor; |
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else |
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quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud); |
|
|
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return quot; |
|
} |
|
|
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EXPORT_SYMBOL(uart_get_divisor); |
|
|
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/* Caller holds port mutex */ |
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static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, |
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struct ktermios *old_termios) |
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{ |
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struct uart_port *uport = uart_port_check(state); |
|
struct ktermios *termios; |
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int hw_stopped; |
|
|
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/* |
|
* If we have no tty, termios, or the port does not exist, |
|
* then we can't set the parameters for this port. |
|
*/ |
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if (!tty || uport->type == PORT_UNKNOWN) |
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return; |
|
|
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termios = &tty->termios; |
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uport->ops->set_termios(uport, termios, old_termios); |
|
|
|
/* |
|
* Set modem status enables based on termios cflag |
|
*/ |
|
spin_lock_irq(&uport->lock); |
|
if (termios->c_cflag & CRTSCTS) |
|
uport->status |= UPSTAT_CTS_ENABLE; |
|
else |
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uport->status &= ~UPSTAT_CTS_ENABLE; |
|
|
|
if (termios->c_cflag & CLOCAL) |
|
uport->status &= ~UPSTAT_DCD_ENABLE; |
|
else |
|
uport->status |= UPSTAT_DCD_ENABLE; |
|
|
|
/* reset sw-assisted CTS flow control based on (possibly) new mode */ |
|
hw_stopped = uport->hw_stopped; |
|
uport->hw_stopped = uart_softcts_mode(uport) && |
|
!(uport->ops->get_mctrl(uport) & TIOCM_CTS); |
|
if (uport->hw_stopped) { |
|
if (!hw_stopped) |
|
uport->ops->stop_tx(uport); |
|
} else { |
|
if (hw_stopped) |
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__uart_start(tty); |
|
} |
|
spin_unlock_irq(&uport->lock); |
|
} |
|
|
|
static int uart_put_char(struct tty_struct *tty, unsigned char c) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *port; |
|
struct circ_buf *circ; |
|
unsigned long flags; |
|
int ret = 0; |
|
|
|
circ = &state->xmit; |
|
port = uart_port_lock(state, flags); |
|
if (!circ->buf) { |
|
uart_port_unlock(port, flags); |
|
return 0; |
|
} |
|
|
|
if (port && uart_circ_chars_free(circ) != 0) { |
|
circ->buf[circ->head] = c; |
|
circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); |
|
ret = 1; |
|
} |
|
uart_port_unlock(port, flags); |
|
return ret; |
|
} |
|
|
|
static void uart_flush_chars(struct tty_struct *tty) |
|
{ |
|
uart_start(tty); |
|
} |
|
|
|
static int uart_write(struct tty_struct *tty, |
|
const unsigned char *buf, int count) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *port; |
|
struct circ_buf *circ; |
|
unsigned long flags; |
|
int c, ret = 0; |
|
|
|
/* |
|
* This means you called this function _after_ the port was |
|
* closed. No cookie for you. |
|
*/ |
|
if (!state) { |
|
WARN_ON(1); |
|
return -EL3HLT; |
|
} |
|
|
|
port = uart_port_lock(state, flags); |
|
circ = &state->xmit; |
|
if (!circ->buf) { |
|
uart_port_unlock(port, flags); |
|
return 0; |
|
} |
|
|
|
while (port) { |
|
c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); |
|
if (count < c) |
|
c = count; |
|
if (c <= 0) |
|
break; |
|
memcpy(circ->buf + circ->head, buf, c); |
|
circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1); |
|
buf += c; |
|
count -= c; |
|
ret += c; |
|
} |
|
|
|
__uart_start(tty); |
|
uart_port_unlock(port, flags); |
|
return ret; |
|
} |
|
|
|
static int uart_write_room(struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *port; |
|
unsigned long flags; |
|
int ret; |
|
|
|
port = uart_port_lock(state, flags); |
|
ret = uart_circ_chars_free(&state->xmit); |
|
uart_port_unlock(port, flags); |
|
return ret; |
|
} |
|
|
|
static int uart_chars_in_buffer(struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *port; |
|
unsigned long flags; |
|
int ret; |
|
|
|
port = uart_port_lock(state, flags); |
|
ret = uart_circ_chars_pending(&state->xmit); |
|
uart_port_unlock(port, flags); |
|
return ret; |
|
} |
|
|
|
static void uart_flush_buffer(struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *port; |
|
unsigned long flags; |
|
|
|
/* |
|
* This means you called this function _after_ the port was |
|
* closed. No cookie for you. |
|
*/ |
|
if (!state) { |
|
WARN_ON(1); |
|
return; |
|
} |
|
|
|
pr_debug("uart_flush_buffer(%d) called\n", tty->index); |
|
|
|
port = uart_port_lock(state, flags); |
|
if (!port) |
|
return; |
|
uart_circ_clear(&state->xmit); |
|
if (port->ops->flush_buffer) |
|
port->ops->flush_buffer(port); |
|
uart_port_unlock(port, flags); |
|
tty_port_tty_wakeup(&state->port); |
|
} |
|
|
|
/* |
|
* This function is used to send a high-priority XON/XOFF character to |
|
* the device |
|
*/ |
|
static void uart_send_xchar(struct tty_struct *tty, char ch) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *port; |
|
unsigned long flags; |
|
|
|
port = uart_port_ref(state); |
|
if (!port) |
|
return; |
|
|
|
if (port->ops->send_xchar) |
|
port->ops->send_xchar(port, ch); |
|
else { |
|
spin_lock_irqsave(&port->lock, flags); |
|
port->x_char = ch; |
|
if (ch) |
|
port->ops->start_tx(port); |
|
spin_unlock_irqrestore(&port->lock, flags); |
|
} |
|
uart_port_deref(port); |
|
} |
|
|
|
static void uart_throttle(struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
upstat_t mask = UPSTAT_SYNC_FIFO; |
|
struct uart_port *port; |
|
|
|
port = uart_port_ref(state); |
|
if (!port) |
|
return; |
|
|
|
if (I_IXOFF(tty)) |
|
mask |= UPSTAT_AUTOXOFF; |
|
if (C_CRTSCTS(tty)) |
|
mask |= UPSTAT_AUTORTS; |
|
|
|
if (port->status & mask) { |
|
port->ops->throttle(port); |
|
mask &= ~port->status; |
|
} |
|
|
|
if (mask & UPSTAT_AUTORTS) |
|
uart_clear_mctrl(port, TIOCM_RTS); |
|
|
|
if (mask & UPSTAT_AUTOXOFF) |
|
uart_send_xchar(tty, STOP_CHAR(tty)); |
|
|
|
uart_port_deref(port); |
|
} |
|
|
|
static void uart_unthrottle(struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
upstat_t mask = UPSTAT_SYNC_FIFO; |
|
struct uart_port *port; |
|
|
|
port = uart_port_ref(state); |
|
if (!port) |
|
return; |
|
|
|
if (I_IXOFF(tty)) |
|
mask |= UPSTAT_AUTOXOFF; |
|
if (C_CRTSCTS(tty)) |
|
mask |= UPSTAT_AUTORTS; |
|
|
|
if (port->status & mask) { |
|
port->ops->unthrottle(port); |
|
mask &= ~port->status; |
|
} |
|
|
|
if (mask & UPSTAT_AUTORTS) |
|
uart_set_mctrl(port, TIOCM_RTS); |
|
|
|
if (mask & UPSTAT_AUTOXOFF) |
|
uart_send_xchar(tty, START_CHAR(tty)); |
|
|
|
uart_port_deref(port); |
|
} |
|
|
|
static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo) |
|
{ |
|
struct uart_state *state = container_of(port, struct uart_state, port); |
|
struct uart_port *uport; |
|
int ret = -ENODEV; |
|
|
|
memset(retinfo, 0, sizeof(*retinfo)); |
|
|
|
/* |
|
* Ensure the state we copy is consistent and no hardware changes |
|
* occur as we go |
|
*/ |
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
if (!uport) |
|
goto out; |
|
|
|
retinfo->type = uport->type; |
|
retinfo->line = uport->line; |
|
retinfo->port = uport->iobase; |
|
if (HIGH_BITS_OFFSET) |
|
retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET; |
|
retinfo->irq = uport->irq; |
|
retinfo->flags = (__force int)uport->flags; |
|
retinfo->xmit_fifo_size = uport->fifosize; |
|
retinfo->baud_base = uport->uartclk / 16; |
|
retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10; |
|
retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ? |
|
ASYNC_CLOSING_WAIT_NONE : |
|
jiffies_to_msecs(port->closing_wait) / 10; |
|
retinfo->custom_divisor = uport->custom_divisor; |
|
retinfo->hub6 = uport->hub6; |
|
retinfo->io_type = uport->iotype; |
|
retinfo->iomem_reg_shift = uport->regshift; |
|
retinfo->iomem_base = (void *)(unsigned long)uport->mapbase; |
|
|
|
ret = 0; |
|
out: |
|
mutex_unlock(&port->mutex); |
|
return ret; |
|
} |
|
|
|
static int uart_get_info_user(struct tty_struct *tty, |
|
struct serial_struct *ss) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct tty_port *port = &state->port; |
|
|
|
return uart_get_info(port, ss) < 0 ? -EIO : 0; |
|
} |
|
|
|
static int uart_set_info(struct tty_struct *tty, struct tty_port *port, |
|
struct uart_state *state, |
|
struct serial_struct *new_info) |
|
{ |
|
struct uart_port *uport = uart_port_check(state); |
|
unsigned long new_port; |
|
unsigned int change_irq, change_port, closing_wait; |
|
unsigned int old_custom_divisor, close_delay; |
|
upf_t old_flags, new_flags; |
|
int retval = 0; |
|
|
|
if (!uport) |
|
return -EIO; |
|
|
|
new_port = new_info->port; |
|
if (HIGH_BITS_OFFSET) |
|
new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET; |
|
|
|
new_info->irq = irq_canonicalize(new_info->irq); |
|
close_delay = msecs_to_jiffies(new_info->close_delay * 10); |
|
closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ? |
|
ASYNC_CLOSING_WAIT_NONE : |
|
msecs_to_jiffies(new_info->closing_wait * 10); |
|
|
|
|
|
change_irq = !(uport->flags & UPF_FIXED_PORT) |
|
&& new_info->irq != uport->irq; |
|
|
|
/* |
|
* Since changing the 'type' of the port changes its resource |
|
* allocations, we should treat type changes the same as |
|
* IO port changes. |
|
*/ |
|
change_port = !(uport->flags & UPF_FIXED_PORT) |
|
&& (new_port != uport->iobase || |
|
(unsigned long)new_info->iomem_base != uport->mapbase || |
|
new_info->hub6 != uport->hub6 || |
|
new_info->io_type != uport->iotype || |
|
new_info->iomem_reg_shift != uport->regshift || |
|
new_info->type != uport->type); |
|
|
|
old_flags = uport->flags; |
|
new_flags = (__force upf_t)new_info->flags; |
|
old_custom_divisor = uport->custom_divisor; |
|
|
|
if (!capable(CAP_SYS_ADMIN)) { |
|
retval = -EPERM; |
|
if (change_irq || change_port || |
|
(new_info->baud_base != uport->uartclk / 16) || |
|
(close_delay != port->close_delay) || |
|
(closing_wait != port->closing_wait) || |
|
(new_info->xmit_fifo_size && |
|
new_info->xmit_fifo_size != uport->fifosize) || |
|
(((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0)) |
|
goto exit; |
|
uport->flags = ((uport->flags & ~UPF_USR_MASK) | |
|
(new_flags & UPF_USR_MASK)); |
|
uport->custom_divisor = new_info->custom_divisor; |
|
goto check_and_exit; |
|
} |
|
|
|
if (change_irq || change_port) { |
|
retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); |
|
if (retval) |
|
goto exit; |
|
} |
|
|
|
/* |
|
* Ask the low level driver to verify the settings. |
|
*/ |
|
if (uport->ops->verify_port) |
|
retval = uport->ops->verify_port(uport, new_info); |
|
|
|
if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) || |
|
(new_info->baud_base < 9600)) |
|
retval = -EINVAL; |
|
|
|
if (retval) |
|
goto exit; |
|
|
|
if (change_port || change_irq) { |
|
retval = -EBUSY; |
|
|
|
/* |
|
* Make sure that we are the sole user of this port. |
|
*/ |
|
if (tty_port_users(port) > 1) |
|
goto exit; |
|
|
|
/* |
|
* We need to shutdown the serial port at the old |
|
* port/type/irq combination. |
|
*/ |
|
uart_shutdown(tty, state); |
|
} |
|
|
|
if (change_port) { |
|
unsigned long old_iobase, old_mapbase; |
|
unsigned int old_type, old_iotype, old_hub6, old_shift; |
|
|
|
old_iobase = uport->iobase; |
|
old_mapbase = uport->mapbase; |
|
old_type = uport->type; |
|
old_hub6 = uport->hub6; |
|
old_iotype = uport->iotype; |
|
old_shift = uport->regshift; |
|
|
|
/* |
|
* Free and release old regions |
|
*/ |
|
if (old_type != PORT_UNKNOWN && uport->ops->release_port) |
|
uport->ops->release_port(uport); |
|
|
|
uport->iobase = new_port; |
|
uport->type = new_info->type; |
|
uport->hub6 = new_info->hub6; |
|
uport->iotype = new_info->io_type; |
|
uport->regshift = new_info->iomem_reg_shift; |
|
uport->mapbase = (unsigned long)new_info->iomem_base; |
|
|
|
/* |
|
* Claim and map the new regions |
|
*/ |
|
if (uport->type != PORT_UNKNOWN && uport->ops->request_port) { |
|
retval = uport->ops->request_port(uport); |
|
} else { |
|
/* Always success - Jean II */ |
|
retval = 0; |
|
} |
|
|
|
/* |
|
* If we fail to request resources for the |
|
* new port, try to restore the old settings. |
|
*/ |
|
if (retval) { |
|
uport->iobase = old_iobase; |
|
uport->type = old_type; |
|
uport->hub6 = old_hub6; |
|
uport->iotype = old_iotype; |
|
uport->regshift = old_shift; |
|
uport->mapbase = old_mapbase; |
|
|
|
if (old_type != PORT_UNKNOWN) { |
|
retval = uport->ops->request_port(uport); |
|
/* |
|
* If we failed to restore the old settings, |
|
* we fail like this. |
|
*/ |
|
if (retval) |
|
uport->type = PORT_UNKNOWN; |
|
|
|
/* |
|
* We failed anyway. |
|
*/ |
|
retval = -EBUSY; |
|
} |
|
|
|
/* Added to return the correct error -Ram Gupta */ |
|
goto exit; |
|
} |
|
} |
|
|
|
if (change_irq) |
|
uport->irq = new_info->irq; |
|
if (!(uport->flags & UPF_FIXED_PORT)) |
|
uport->uartclk = new_info->baud_base * 16; |
|
uport->flags = (uport->flags & ~UPF_CHANGE_MASK) | |
|
(new_flags & UPF_CHANGE_MASK); |
|
uport->custom_divisor = new_info->custom_divisor; |
|
port->close_delay = close_delay; |
|
port->closing_wait = closing_wait; |
|
if (new_info->xmit_fifo_size) |
|
uport->fifosize = new_info->xmit_fifo_size; |
|
|
|
check_and_exit: |
|
retval = 0; |
|
if (uport->type == PORT_UNKNOWN) |
|
goto exit; |
|
if (tty_port_initialized(port)) { |
|
if (((old_flags ^ uport->flags) & UPF_SPD_MASK) || |
|
old_custom_divisor != uport->custom_divisor) { |
|
/* |
|
* If they're setting up a custom divisor or speed, |
|
* instead of clearing it, then bitch about it. |
|
*/ |
|
if (uport->flags & UPF_SPD_MASK) { |
|
dev_notice_ratelimited(uport->dev, |
|
"%s sets custom speed on %s. This is deprecated.\n", |
|
current->comm, |
|
tty_name(port->tty)); |
|
} |
|
uart_change_speed(tty, state, NULL); |
|
} |
|
} else { |
|
retval = uart_startup(tty, state, 1); |
|
if (retval == 0) |
|
tty_port_set_initialized(port, true); |
|
if (retval > 0) |
|
retval = 0; |
|
} |
|
exit: |
|
return retval; |
|
} |
|
|
|
static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct tty_port *port = &state->port; |
|
int retval; |
|
|
|
down_write(&tty->termios_rwsem); |
|
/* |
|
* This semaphore protects port->count. It is also |
|
* very useful to prevent opens. Also, take the |
|
* port configuration semaphore to make sure that a |
|
* module insertion/removal doesn't change anything |
|
* under us. |
|
*/ |
|
mutex_lock(&port->mutex); |
|
retval = uart_set_info(tty, port, state, ss); |
|
mutex_unlock(&port->mutex); |
|
up_write(&tty->termios_rwsem); |
|
return retval; |
|
} |
|
|
|
/** |
|
* uart_get_lsr_info - get line status register info |
|
* @tty: tty associated with the UART |
|
* @state: UART being queried |
|
* @value: returned modem value |
|
*/ |
|
static int uart_get_lsr_info(struct tty_struct *tty, |
|
struct uart_state *state, unsigned int __user *value) |
|
{ |
|
struct uart_port *uport = uart_port_check(state); |
|
unsigned int result; |
|
|
|
result = uport->ops->tx_empty(uport); |
|
|
|
/* |
|
* If we're about to load something into the transmit |
|
* register, we'll pretend the transmitter isn't empty to |
|
* avoid a race condition (depending on when the transmit |
|
* interrupt happens). |
|
*/ |
|
if (uport->x_char || |
|
((uart_circ_chars_pending(&state->xmit) > 0) && |
|
!uart_tx_stopped(uport))) |
|
result &= ~TIOCSER_TEMT; |
|
|
|
return put_user(result, value); |
|
} |
|
|
|
static int uart_tiocmget(struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct tty_port *port = &state->port; |
|
struct uart_port *uport; |
|
int result = -EIO; |
|
|
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
if (!uport) |
|
goto out; |
|
|
|
if (!tty_io_error(tty)) { |
|
result = uport->mctrl; |
|
spin_lock_irq(&uport->lock); |
|
result |= uport->ops->get_mctrl(uport); |
|
spin_unlock_irq(&uport->lock); |
|
} |
|
out: |
|
mutex_unlock(&port->mutex); |
|
return result; |
|
} |
|
|
|
static int |
|
uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct tty_port *port = &state->port; |
|
struct uart_port *uport; |
|
int ret = -EIO; |
|
|
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
if (!uport) |
|
goto out; |
|
|
|
if (!tty_io_error(tty)) { |
|
uart_update_mctrl(uport, set, clear); |
|
ret = 0; |
|
} |
|
out: |
|
mutex_unlock(&port->mutex); |
|
return ret; |
|
} |
|
|
|
static int uart_break_ctl(struct tty_struct *tty, int break_state) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct tty_port *port = &state->port; |
|
struct uart_port *uport; |
|
int ret = -EIO; |
|
|
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
if (!uport) |
|
goto out; |
|
|
|
if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl) |
|
uport->ops->break_ctl(uport, break_state); |
|
ret = 0; |
|
out: |
|
mutex_unlock(&port->mutex); |
|
return ret; |
|
} |
|
|
|
static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state) |
|
{ |
|
struct tty_port *port = &state->port; |
|
struct uart_port *uport; |
|
int flags, ret; |
|
|
|
if (!capable(CAP_SYS_ADMIN)) |
|
return -EPERM; |
|
|
|
/* |
|
* Take the per-port semaphore. This prevents count from |
|
* changing, and hence any extra opens of the port while |
|
* we're auto-configuring. |
|
*/ |
|
if (mutex_lock_interruptible(&port->mutex)) |
|
return -ERESTARTSYS; |
|
|
|
uport = uart_port_check(state); |
|
if (!uport) { |
|
ret = -EIO; |
|
goto out; |
|
} |
|
|
|
ret = -EBUSY; |
|
if (tty_port_users(port) == 1) { |
|
uart_shutdown(tty, state); |
|
|
|
/* |
|
* If we already have a port type configured, |
|
* we must release its resources. |
|
*/ |
|
if (uport->type != PORT_UNKNOWN && uport->ops->release_port) |
|
uport->ops->release_port(uport); |
|
|
|
flags = UART_CONFIG_TYPE; |
|
if (uport->flags & UPF_AUTO_IRQ) |
|
flags |= UART_CONFIG_IRQ; |
|
|
|
/* |
|
* This will claim the ports resources if |
|
* a port is found. |
|
*/ |
|
uport->ops->config_port(uport, flags); |
|
|
|
ret = uart_startup(tty, state, 1); |
|
if (ret == 0) |
|
tty_port_set_initialized(port, true); |
|
if (ret > 0) |
|
ret = 0; |
|
} |
|
out: |
|
mutex_unlock(&port->mutex); |
|
return ret; |
|
} |
|
|
|
static void uart_enable_ms(struct uart_port *uport) |
|
{ |
|
/* |
|
* Force modem status interrupts on |
|
*/ |
|
if (uport->ops->enable_ms) |
|
uport->ops->enable_ms(uport); |
|
} |
|
|
|
/* |
|
* Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change |
|
* - mask passed in arg for lines of interest |
|
* (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) |
|
* Caller should use TIOCGICOUNT to see which one it was |
|
* |
|
* FIXME: This wants extracting into a common all driver implementation |
|
* of TIOCMWAIT using tty_port. |
|
*/ |
|
static int uart_wait_modem_status(struct uart_state *state, unsigned long arg) |
|
{ |
|
struct uart_port *uport; |
|
struct tty_port *port = &state->port; |
|
DECLARE_WAITQUEUE(wait, current); |
|
struct uart_icount cprev, cnow; |
|
int ret; |
|
|
|
/* |
|
* note the counters on entry |
|
*/ |
|
uport = uart_port_ref(state); |
|
if (!uport) |
|
return -EIO; |
|
spin_lock_irq(&uport->lock); |
|
memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); |
|
uart_enable_ms(uport); |
|
spin_unlock_irq(&uport->lock); |
|
|
|
add_wait_queue(&port->delta_msr_wait, &wait); |
|
for (;;) { |
|
spin_lock_irq(&uport->lock); |
|
memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); |
|
spin_unlock_irq(&uport->lock); |
|
|
|
set_current_state(TASK_INTERRUPTIBLE); |
|
|
|
if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || |
|
((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || |
|
((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || |
|
((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) { |
|
ret = 0; |
|
break; |
|
} |
|
|
|
schedule(); |
|
|
|
/* see if a signal did it */ |
|
if (signal_pending(current)) { |
|
ret = -ERESTARTSYS; |
|
break; |
|
} |
|
|
|
cprev = cnow; |
|
} |
|
__set_current_state(TASK_RUNNING); |
|
remove_wait_queue(&port->delta_msr_wait, &wait); |
|
uart_port_deref(uport); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Get counter of input serial line interrupts (DCD,RI,DSR,CTS) |
|
* Return: write counters to the user passed counter struct |
|
* NB: both 1->0 and 0->1 transitions are counted except for |
|
* RI where only 0->1 is counted. |
|
*/ |
|
static int uart_get_icount(struct tty_struct *tty, |
|
struct serial_icounter_struct *icount) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_icount cnow; |
|
struct uart_port *uport; |
|
|
|
uport = uart_port_ref(state); |
|
if (!uport) |
|
return -EIO; |
|
spin_lock_irq(&uport->lock); |
|
memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); |
|
spin_unlock_irq(&uport->lock); |
|
uart_port_deref(uport); |
|
|
|
icount->cts = cnow.cts; |
|
icount->dsr = cnow.dsr; |
|
icount->rng = cnow.rng; |
|
icount->dcd = cnow.dcd; |
|
icount->rx = cnow.rx; |
|
icount->tx = cnow.tx; |
|
icount->frame = cnow.frame; |
|
icount->overrun = cnow.overrun; |
|
icount->parity = cnow.parity; |
|
icount->brk = cnow.brk; |
|
icount->buf_overrun = cnow.buf_overrun; |
|
|
|
return 0; |
|
} |
|
|
|
static int uart_get_rs485_config(struct uart_port *port, |
|
struct serial_rs485 __user *rs485) |
|
{ |
|
unsigned long flags; |
|
struct serial_rs485 aux; |
|
|
|
spin_lock_irqsave(&port->lock, flags); |
|
aux = port->rs485; |
|
spin_unlock_irqrestore(&port->lock, flags); |
|
|
|
if (copy_to_user(rs485, &aux, sizeof(aux))) |
|
return -EFAULT; |
|
|
|
return 0; |
|
} |
|
|
|
static int uart_set_rs485_config(struct uart_port *port, |
|
struct serial_rs485 __user *rs485_user) |
|
{ |
|
struct serial_rs485 rs485; |
|
int ret; |
|
unsigned long flags; |
|
|
|
if (!port->rs485_config) |
|
return -ENOTTY; |
|
|
|
if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user))) |
|
return -EFAULT; |
|
|
|
spin_lock_irqsave(&port->lock, flags); |
|
ret = port->rs485_config(port, &rs485); |
|
spin_unlock_irqrestore(&port->lock, flags); |
|
if (ret) |
|
return ret; |
|
|
|
if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485))) |
|
return -EFAULT; |
|
|
|
return 0; |
|
} |
|
|
|
static int uart_get_iso7816_config(struct uart_port *port, |
|
struct serial_iso7816 __user *iso7816) |
|
{ |
|
unsigned long flags; |
|
struct serial_iso7816 aux; |
|
|
|
if (!port->iso7816_config) |
|
return -ENOTTY; |
|
|
|
spin_lock_irqsave(&port->lock, flags); |
|
aux = port->iso7816; |
|
spin_unlock_irqrestore(&port->lock, flags); |
|
|
|
if (copy_to_user(iso7816, &aux, sizeof(aux))) |
|
return -EFAULT; |
|
|
|
return 0; |
|
} |
|
|
|
static int uart_set_iso7816_config(struct uart_port *port, |
|
struct serial_iso7816 __user *iso7816_user) |
|
{ |
|
struct serial_iso7816 iso7816; |
|
int i, ret; |
|
unsigned long flags; |
|
|
|
if (!port->iso7816_config) |
|
return -ENOTTY; |
|
|
|
if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user))) |
|
return -EFAULT; |
|
|
|
/* |
|
* There are 5 words reserved for future use. Check that userspace |
|
* doesn't put stuff in there to prevent breakages in the future. |
|
*/ |
|
for (i = 0; i < 5; i++) |
|
if (iso7816.reserved[i]) |
|
return -EINVAL; |
|
|
|
spin_lock_irqsave(&port->lock, flags); |
|
ret = port->iso7816_config(port, &iso7816); |
|
spin_unlock_irqrestore(&port->lock, flags); |
|
if (ret) |
|
return ret; |
|
|
|
if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816))) |
|
return -EFAULT; |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Called via sys_ioctl. We can use spin_lock_irq() here. |
|
*/ |
|
static int |
|
uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct tty_port *port = &state->port; |
|
struct uart_port *uport; |
|
void __user *uarg = (void __user *)arg; |
|
int ret = -ENOIOCTLCMD; |
|
|
|
|
|
/* |
|
* These ioctls don't rely on the hardware to be present. |
|
*/ |
|
switch (cmd) { |
|
case TIOCSERCONFIG: |
|
down_write(&tty->termios_rwsem); |
|
ret = uart_do_autoconfig(tty, state); |
|
up_write(&tty->termios_rwsem); |
|
break; |
|
} |
|
|
|
if (ret != -ENOIOCTLCMD) |
|
goto out; |
|
|
|
if (tty_io_error(tty)) { |
|
ret = -EIO; |
|
goto out; |
|
} |
|
|
|
/* |
|
* The following should only be used when hardware is present. |
|
*/ |
|
switch (cmd) { |
|
case TIOCMIWAIT: |
|
ret = uart_wait_modem_status(state, arg); |
|
break; |
|
} |
|
|
|
if (ret != -ENOIOCTLCMD) |
|
goto out; |
|
|
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
|
|
if (!uport || tty_io_error(tty)) { |
|
ret = -EIO; |
|
goto out_up; |
|
} |
|
|
|
/* |
|
* All these rely on hardware being present and need to be |
|
* protected against the tty being hung up. |
|
*/ |
|
|
|
switch (cmd) { |
|
case TIOCSERGETLSR: /* Get line status register */ |
|
ret = uart_get_lsr_info(tty, state, uarg); |
|
break; |
|
|
|
case TIOCGRS485: |
|
ret = uart_get_rs485_config(uport, uarg); |
|
break; |
|
|
|
case TIOCSRS485: |
|
ret = uart_set_rs485_config(uport, uarg); |
|
break; |
|
|
|
case TIOCSISO7816: |
|
ret = uart_set_iso7816_config(state->uart_port, uarg); |
|
break; |
|
|
|
case TIOCGISO7816: |
|
ret = uart_get_iso7816_config(state->uart_port, uarg); |
|
break; |
|
default: |
|
if (uport->ops->ioctl) |
|
ret = uport->ops->ioctl(uport, cmd, arg); |
|
break; |
|
} |
|
out_up: |
|
mutex_unlock(&port->mutex); |
|
out: |
|
return ret; |
|
} |
|
|
|
static void uart_set_ldisc(struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *uport; |
|
struct tty_port *port = &state->port; |
|
|
|
if (!tty_port_initialized(port)) |
|
return; |
|
|
|
mutex_lock(&state->port.mutex); |
|
uport = uart_port_check(state); |
|
if (uport && uport->ops->set_ldisc) |
|
uport->ops->set_ldisc(uport, &tty->termios); |
|
mutex_unlock(&state->port.mutex); |
|
} |
|
|
|
static void uart_set_termios(struct tty_struct *tty, |
|
struct ktermios *old_termios) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *uport; |
|
unsigned int cflag = tty->termios.c_cflag; |
|
unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK; |
|
bool sw_changed = false; |
|
|
|
mutex_lock(&state->port.mutex); |
|
uport = uart_port_check(state); |
|
if (!uport) |
|
goto out; |
|
|
|
/* |
|
* Drivers doing software flow control also need to know |
|
* about changes to these input settings. |
|
*/ |
|
if (uport->flags & UPF_SOFT_FLOW) { |
|
iflag_mask |= IXANY|IXON|IXOFF; |
|
sw_changed = |
|
tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] || |
|
tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP]; |
|
} |
|
|
|
/* |
|
* These are the bits that are used to setup various |
|
* flags in the low level driver. We can ignore the Bfoo |
|
* bits in c_cflag; c_[io]speed will always be set |
|
* appropriately by set_termios() in tty_ioctl.c |
|
*/ |
|
if ((cflag ^ old_termios->c_cflag) == 0 && |
|
tty->termios.c_ospeed == old_termios->c_ospeed && |
|
tty->termios.c_ispeed == old_termios->c_ispeed && |
|
((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 && |
|
!sw_changed) { |
|
goto out; |
|
} |
|
|
|
uart_change_speed(tty, state, old_termios); |
|
/* reload cflag from termios; port driver may have overridden flags */ |
|
cflag = tty->termios.c_cflag; |
|
|
|
/* Handle transition to B0 status */ |
|
if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) |
|
uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR); |
|
/* Handle transition away from B0 status */ |
|
else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { |
|
unsigned int mask = TIOCM_DTR; |
|
|
|
if (!(cflag & CRTSCTS) || !tty_throttled(tty)) |
|
mask |= TIOCM_RTS; |
|
uart_set_mctrl(uport, mask); |
|
} |
|
out: |
|
mutex_unlock(&state->port.mutex); |
|
} |
|
|
|
/* |
|
* Calls to uart_close() are serialised via the tty_lock in |
|
* drivers/tty/tty_io.c:tty_release() |
|
* drivers/tty/tty_io.c:do_tty_hangup() |
|
*/ |
|
static void uart_close(struct tty_struct *tty, struct file *filp) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
|
|
if (!state) { |
|
struct uart_driver *drv = tty->driver->driver_state; |
|
struct tty_port *port; |
|
|
|
state = drv->state + tty->index; |
|
port = &state->port; |
|
spin_lock_irq(&port->lock); |
|
--port->count; |
|
spin_unlock_irq(&port->lock); |
|
return; |
|
} |
|
|
|
pr_debug("uart_close(%d) called\n", tty->index); |
|
|
|
tty_port_close(tty->port, tty, filp); |
|
} |
|
|
|
static void uart_tty_port_shutdown(struct tty_port *port) |
|
{ |
|
struct uart_state *state = container_of(port, struct uart_state, port); |
|
struct uart_port *uport = uart_port_check(state); |
|
|
|
/* |
|
* At this point, we stop accepting input. To do this, we |
|
* disable the receive line status interrupts. |
|
*/ |
|
if (WARN(!uport, "detached port still initialized!\n")) |
|
return; |
|
|
|
spin_lock_irq(&uport->lock); |
|
uport->ops->stop_rx(uport); |
|
spin_unlock_irq(&uport->lock); |
|
|
|
uart_port_shutdown(port); |
|
|
|
/* |
|
* It's possible for shutdown to be called after suspend if we get |
|
* a DCD drop (hangup) at just the right time. Clear suspended bit so |
|
* we don't try to resume a port that has been shutdown. |
|
*/ |
|
tty_port_set_suspended(port, 0); |
|
|
|
uart_change_pm(state, UART_PM_STATE_OFF); |
|
|
|
} |
|
|
|
static void uart_wait_until_sent(struct tty_struct *tty, int timeout) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct uart_port *port; |
|
unsigned long char_time, expire; |
|
|
|
port = uart_port_ref(state); |
|
if (!port) |
|
return; |
|
|
|
if (port->type == PORT_UNKNOWN || port->fifosize == 0) { |
|
uart_port_deref(port); |
|
return; |
|
} |
|
|
|
/* |
|
* Set the check interval to be 1/5 of the estimated time to |
|
* send a single character, and make it at least 1. The check |
|
* interval should also be less than the timeout. |
|
* |
|
* Note: we have to use pretty tight timings here to satisfy |
|
* the NIST-PCTS. |
|
*/ |
|
char_time = (port->timeout - HZ/50) / port->fifosize; |
|
char_time = char_time / 5; |
|
if (char_time == 0) |
|
char_time = 1; |
|
if (timeout && timeout < char_time) |
|
char_time = timeout; |
|
|
|
/* |
|
* If the transmitter hasn't cleared in twice the approximate |
|
* amount of time to send the entire FIFO, it probably won't |
|
* ever clear. This assumes the UART isn't doing flow |
|
* control, which is currently the case. Hence, if it ever |
|
* takes longer than port->timeout, this is probably due to a |
|
* UART bug of some kind. So, we clamp the timeout parameter at |
|
* 2*port->timeout. |
|
*/ |
|
if (timeout == 0 || timeout > 2 * port->timeout) |
|
timeout = 2 * port->timeout; |
|
|
|
expire = jiffies + timeout; |
|
|
|
pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n", |
|
port->line, jiffies, expire); |
|
|
|
/* |
|
* Check whether the transmitter is empty every 'char_time'. |
|
* 'timeout' / 'expire' give us the maximum amount of time |
|
* we wait. |
|
*/ |
|
while (!port->ops->tx_empty(port)) { |
|
msleep_interruptible(jiffies_to_msecs(char_time)); |
|
if (signal_pending(current)) |
|
break; |
|
if (time_after(jiffies, expire)) |
|
break; |
|
} |
|
uart_port_deref(port); |
|
} |
|
|
|
/* |
|
* Calls to uart_hangup() are serialised by the tty_lock in |
|
* drivers/tty/tty_io.c:do_tty_hangup() |
|
* This runs from a workqueue and can sleep for a _short_ time only. |
|
*/ |
|
static void uart_hangup(struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
struct tty_port *port = &state->port; |
|
struct uart_port *uport; |
|
unsigned long flags; |
|
|
|
pr_debug("uart_hangup(%d)\n", tty->index); |
|
|
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
WARN(!uport, "hangup of detached port!\n"); |
|
|
|
if (tty_port_active(port)) { |
|
uart_flush_buffer(tty); |
|
uart_shutdown(tty, state); |
|
spin_lock_irqsave(&port->lock, flags); |
|
port->count = 0; |
|
spin_unlock_irqrestore(&port->lock, flags); |
|
tty_port_set_active(port, 0); |
|
tty_port_tty_set(port, NULL); |
|
if (uport && !uart_console(uport)) |
|
uart_change_pm(state, UART_PM_STATE_OFF); |
|
wake_up_interruptible(&port->open_wait); |
|
wake_up_interruptible(&port->delta_msr_wait); |
|
} |
|
mutex_unlock(&port->mutex); |
|
} |
|
|
|
/* uport == NULL if uart_port has already been removed */ |
|
static void uart_port_shutdown(struct tty_port *port) |
|
{ |
|
struct uart_state *state = container_of(port, struct uart_state, port); |
|
struct uart_port *uport = uart_port_check(state); |
|
|
|
/* |
|
* clear delta_msr_wait queue to avoid mem leaks: we may free |
|
* the irq here so the queue might never be woken up. Note |
|
* that we won't end up waiting on delta_msr_wait again since |
|
* any outstanding file descriptors should be pointing at |
|
* hung_up_tty_fops now. |
|
*/ |
|
wake_up_interruptible(&port->delta_msr_wait); |
|
|
|
/* |
|
* Free the IRQ and disable the port. |
|
*/ |
|
if (uport) |
|
uport->ops->shutdown(uport); |
|
|
|
/* |
|
* Ensure that the IRQ handler isn't running on another CPU. |
|
*/ |
|
if (uport) |
|
synchronize_irq(uport->irq); |
|
} |
|
|
|
static int uart_carrier_raised(struct tty_port *port) |
|
{ |
|
struct uart_state *state = container_of(port, struct uart_state, port); |
|
struct uart_port *uport; |
|
int mctrl; |
|
|
|
uport = uart_port_ref(state); |
|
/* |
|
* Should never observe uport == NULL since checks for hangup should |
|
* abort the tty_port_block_til_ready() loop before checking for carrier |
|
* raised -- but report carrier raised if it does anyway so open will |
|
* continue and not sleep |
|
*/ |
|
if (WARN_ON(!uport)) |
|
return 1; |
|
spin_lock_irq(&uport->lock); |
|
uart_enable_ms(uport); |
|
mctrl = uport->ops->get_mctrl(uport); |
|
spin_unlock_irq(&uport->lock); |
|
uart_port_deref(uport); |
|
if (mctrl & TIOCM_CAR) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
static void uart_dtr_rts(struct tty_port *port, int raise) |
|
{ |
|
struct uart_state *state = container_of(port, struct uart_state, port); |
|
struct uart_port *uport; |
|
|
|
uport = uart_port_ref(state); |
|
if (!uport) |
|
return; |
|
uart_port_dtr_rts(uport, raise); |
|
uart_port_deref(uport); |
|
} |
|
|
|
static int uart_install(struct tty_driver *driver, struct tty_struct *tty) |
|
{ |
|
struct uart_driver *drv = driver->driver_state; |
|
struct uart_state *state = drv->state + tty->index; |
|
|
|
tty->driver_data = state; |
|
|
|
return tty_standard_install(driver, tty); |
|
} |
|
|
|
/* |
|
* Calls to uart_open are serialised by the tty_lock in |
|
* drivers/tty/tty_io.c:tty_open() |
|
* Note that if this fails, then uart_close() _will_ be called. |
|
* |
|
* In time, we want to scrap the "opening nonpresent ports" |
|
* behaviour and implement an alternative way for setserial |
|
* to set base addresses/ports/types. This will allow us to |
|
* get rid of a certain amount of extra tests. |
|
*/ |
|
static int uart_open(struct tty_struct *tty, struct file *filp) |
|
{ |
|
struct uart_state *state = tty->driver_data; |
|
int retval; |
|
|
|
retval = tty_port_open(&state->port, tty, filp); |
|
if (retval > 0) |
|
retval = 0; |
|
|
|
return retval; |
|
} |
|
|
|
static int uart_port_activate(struct tty_port *port, struct tty_struct *tty) |
|
{ |
|
struct uart_state *state = container_of(port, struct uart_state, port); |
|
struct uart_port *uport; |
|
int ret; |
|
|
|
uport = uart_port_check(state); |
|
if (!uport || uport->flags & UPF_DEAD) |
|
return -ENXIO; |
|
|
|
/* |
|
* Start up the serial port. |
|
*/ |
|
ret = uart_startup(tty, state, 0); |
|
if (ret > 0) |
|
tty_port_set_active(port, 1); |
|
|
|
return ret; |
|
} |
|
|
|
static const char *uart_type(struct uart_port *port) |
|
{ |
|
const char *str = NULL; |
|
|
|
if (port->ops->type) |
|
str = port->ops->type(port); |
|
|
|
if (!str) |
|
str = "unknown"; |
|
|
|
return str; |
|
} |
|
|
|
#ifdef CONFIG_PROC_FS |
|
|
|
static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) |
|
{ |
|
struct uart_state *state = drv->state + i; |
|
struct tty_port *port = &state->port; |
|
enum uart_pm_state pm_state; |
|
struct uart_port *uport; |
|
char stat_buf[32]; |
|
unsigned int status; |
|
int mmio; |
|
|
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
if (!uport) |
|
goto out; |
|
|
|
mmio = uport->iotype >= UPIO_MEM; |
|
seq_printf(m, "%d: uart:%s %s%08llX irq:%d", |
|
uport->line, uart_type(uport), |
|
mmio ? "mmio:0x" : "port:", |
|
mmio ? (unsigned long long)uport->mapbase |
|
: (unsigned long long)uport->iobase, |
|
uport->irq); |
|
|
|
if (uport->type == PORT_UNKNOWN) { |
|
seq_putc(m, '\n'); |
|
goto out; |
|
} |
|
|
|
if (capable(CAP_SYS_ADMIN)) { |
|
pm_state = state->pm_state; |
|
if (pm_state != UART_PM_STATE_ON) |
|
uart_change_pm(state, UART_PM_STATE_ON); |
|
spin_lock_irq(&uport->lock); |
|
status = uport->ops->get_mctrl(uport); |
|
spin_unlock_irq(&uport->lock); |
|
if (pm_state != UART_PM_STATE_ON) |
|
uart_change_pm(state, pm_state); |
|
|
|
seq_printf(m, " tx:%d rx:%d", |
|
uport->icount.tx, uport->icount.rx); |
|
if (uport->icount.frame) |
|
seq_printf(m, " fe:%d", uport->icount.frame); |
|
if (uport->icount.parity) |
|
seq_printf(m, " pe:%d", uport->icount.parity); |
|
if (uport->icount.brk) |
|
seq_printf(m, " brk:%d", uport->icount.brk); |
|
if (uport->icount.overrun) |
|
seq_printf(m, " oe:%d", uport->icount.overrun); |
|
if (uport->icount.buf_overrun) |
|
seq_printf(m, " bo:%d", uport->icount.buf_overrun); |
|
|
|
#define INFOBIT(bit, str) \ |
|
if (uport->mctrl & (bit)) \ |
|
strncat(stat_buf, (str), sizeof(stat_buf) - \ |
|
strlen(stat_buf) - 2) |
|
#define STATBIT(bit, str) \ |
|
if (status & (bit)) \ |
|
strncat(stat_buf, (str), sizeof(stat_buf) - \ |
|
strlen(stat_buf) - 2) |
|
|
|
stat_buf[0] = '\0'; |
|
stat_buf[1] = '\0'; |
|
INFOBIT(TIOCM_RTS, "|RTS"); |
|
STATBIT(TIOCM_CTS, "|CTS"); |
|
INFOBIT(TIOCM_DTR, "|DTR"); |
|
STATBIT(TIOCM_DSR, "|DSR"); |
|
STATBIT(TIOCM_CAR, "|CD"); |
|
STATBIT(TIOCM_RNG, "|RI"); |
|
if (stat_buf[0]) |
|
stat_buf[0] = ' '; |
|
|
|
seq_puts(m, stat_buf); |
|
} |
|
seq_putc(m, '\n'); |
|
#undef STATBIT |
|
#undef INFOBIT |
|
out: |
|
mutex_unlock(&port->mutex); |
|
} |
|
|
|
static int uart_proc_show(struct seq_file *m, void *v) |
|
{ |
|
struct tty_driver *ttydrv = m->private; |
|
struct uart_driver *drv = ttydrv->driver_state; |
|
int i; |
|
|
|
seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", ""); |
|
for (i = 0; i < drv->nr; i++) |
|
uart_line_info(m, drv, i); |
|
return 0; |
|
} |
|
#endif |
|
|
|
static inline bool uart_console_enabled(struct uart_port *port) |
|
{ |
|
return uart_console(port) && (port->cons->flags & CON_ENABLED); |
|
} |
|
|
|
static void uart_port_spin_lock_init(struct uart_port *port) |
|
{ |
|
spin_lock_init(&port->lock); |
|
lockdep_set_class(&port->lock, &port_lock_key); |
|
} |
|
|
|
#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL) |
|
/** |
|
* uart_console_write - write a console message to a serial port |
|
* @port: the port to write the message |
|
* @s: array of characters |
|
* @count: number of characters in string to write |
|
* @putchar: function to write character to port |
|
*/ |
|
void uart_console_write(struct uart_port *port, const char *s, |
|
unsigned int count, |
|
void (*putchar)(struct uart_port *, int)) |
|
{ |
|
unsigned int i; |
|
|
|
for (i = 0; i < count; i++, s++) { |
|
if (*s == '\n') |
|
putchar(port, '\r'); |
|
putchar(port, *s); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(uart_console_write); |
|
|
|
/* |
|
* Check whether an invalid uart number has been specified, and |
|
* if so, search for the first available port that does have |
|
* console support. |
|
*/ |
|
struct uart_port * __init |
|
uart_get_console(struct uart_port *ports, int nr, struct console *co) |
|
{ |
|
int idx = co->index; |
|
|
|
if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 && |
|
ports[idx].membase == NULL)) |
|
for (idx = 0; idx < nr; idx++) |
|
if (ports[idx].iobase != 0 || |
|
ports[idx].membase != NULL) |
|
break; |
|
|
|
co->index = idx; |
|
|
|
return ports + idx; |
|
} |
|
|
|
/** |
|
* uart_parse_earlycon - Parse earlycon options |
|
* @p: ptr to 2nd field (ie., just beyond '<name>,') |
|
* @iotype: ptr for decoded iotype (out) |
|
* @addr: ptr for decoded mapbase/iobase (out) |
|
* @options: ptr for <options> field; NULL if not present (out) |
|
* |
|
* Decodes earlycon kernel command line parameters of the form |
|
* earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> |
|
* console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> |
|
* |
|
* The optional form |
|
* |
|
* earlycon=<name>,0x<addr>,<options> |
|
* console=<name>,0x<addr>,<options> |
|
* |
|
* is also accepted; the returned @iotype will be UPIO_MEM. |
|
* |
|
* Returns 0 on success or -EINVAL on failure |
|
*/ |
|
int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, |
|
char **options) |
|
{ |
|
if (strncmp(p, "mmio,", 5) == 0) { |
|
*iotype = UPIO_MEM; |
|
p += 5; |
|
} else if (strncmp(p, "mmio16,", 7) == 0) { |
|
*iotype = UPIO_MEM16; |
|
p += 7; |
|
} else if (strncmp(p, "mmio32,", 7) == 0) { |
|
*iotype = UPIO_MEM32; |
|
p += 7; |
|
} else if (strncmp(p, "mmio32be,", 9) == 0) { |
|
*iotype = UPIO_MEM32BE; |
|
p += 9; |
|
} else if (strncmp(p, "mmio32native,", 13) == 0) { |
|
*iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ? |
|
UPIO_MEM32BE : UPIO_MEM32; |
|
p += 13; |
|
} else if (strncmp(p, "io,", 3) == 0) { |
|
*iotype = UPIO_PORT; |
|
p += 3; |
|
} else if (strncmp(p, "0x", 2) == 0) { |
|
*iotype = UPIO_MEM; |
|
} else { |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* Before you replace it with kstrtoull(), think about options separator |
|
* (',') it will not tolerate |
|
*/ |
|
*addr = simple_strtoull(p, NULL, 0); |
|
p = strchr(p, ','); |
|
if (p) |
|
p++; |
|
|
|
*options = p; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(uart_parse_earlycon); |
|
|
|
/** |
|
* uart_parse_options - Parse serial port baud/parity/bits/flow control. |
|
* @options: pointer to option string |
|
* @baud: pointer to an 'int' variable for the baud rate. |
|
* @parity: pointer to an 'int' variable for the parity. |
|
* @bits: pointer to an 'int' variable for the number of data bits. |
|
* @flow: pointer to an 'int' variable for the flow control character. |
|
* |
|
* uart_parse_options decodes a string containing the serial console |
|
* options. The format of the string is <baud><parity><bits><flow>, |
|
* eg: 115200n8r |
|
*/ |
|
void |
|
uart_parse_options(const char *options, int *baud, int *parity, |
|
int *bits, int *flow) |
|
{ |
|
const char *s = options; |
|
|
|
*baud = simple_strtoul(s, NULL, 10); |
|
while (*s >= '0' && *s <= '9') |
|
s++; |
|
if (*s) |
|
*parity = *s++; |
|
if (*s) |
|
*bits = *s++ - '0'; |
|
if (*s) |
|
*flow = *s; |
|
} |
|
EXPORT_SYMBOL_GPL(uart_parse_options); |
|
|
|
/** |
|
* uart_set_options - setup the serial console parameters |
|
* @port: pointer to the serial ports uart_port structure |
|
* @co: console pointer |
|
* @baud: baud rate |
|
* @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) |
|
* @bits: number of data bits |
|
* @flow: flow control character - 'r' (rts) |
|
*/ |
|
int |
|
uart_set_options(struct uart_port *port, struct console *co, |
|
int baud, int parity, int bits, int flow) |
|
{ |
|
struct ktermios termios; |
|
static struct ktermios dummy; |
|
|
|
/* |
|
* Ensure that the serial-console lock is initialised early. |
|
* |
|
* Note that the console-enabled check is needed because of kgdboc, |
|
* which can end up calling uart_set_options() for an already enabled |
|
* console via tty_find_polling_driver() and uart_poll_init(). |
|
*/ |
|
if (!uart_console_enabled(port) && !port->console_reinit) |
|
uart_port_spin_lock_init(port); |
|
|
|
memset(&termios, 0, sizeof(struct ktermios)); |
|
|
|
termios.c_cflag |= CREAD | HUPCL | CLOCAL; |
|
tty_termios_encode_baud_rate(&termios, baud, baud); |
|
|
|
if (bits == 7) |
|
termios.c_cflag |= CS7; |
|
else |
|
termios.c_cflag |= CS8; |
|
|
|
switch (parity) { |
|
case 'o': case 'O': |
|
termios.c_cflag |= PARODD; |
|
fallthrough; |
|
case 'e': case 'E': |
|
termios.c_cflag |= PARENB; |
|
break; |
|
} |
|
|
|
if (flow == 'r') |
|
termios.c_cflag |= CRTSCTS; |
|
|
|
/* |
|
* some uarts on other side don't support no flow control. |
|
* So we set * DTR in host uart to make them happy |
|
*/ |
|
port->mctrl |= TIOCM_DTR; |
|
|
|
port->ops->set_termios(port, &termios, &dummy); |
|
/* |
|
* Allow the setting of the UART parameters with a NULL console |
|
* too: |
|
*/ |
|
if (co) |
|
co->cflag = termios.c_cflag; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(uart_set_options); |
|
#endif /* CONFIG_SERIAL_CORE_CONSOLE */ |
|
|
|
/** |
|
* uart_change_pm - set power state of the port |
|
* |
|
* @state: port descriptor |
|
* @pm_state: new state |
|
* |
|
* Locking: port->mutex has to be held |
|
*/ |
|
static void uart_change_pm(struct uart_state *state, |
|
enum uart_pm_state pm_state) |
|
{ |
|
struct uart_port *port = uart_port_check(state); |
|
|
|
if (state->pm_state != pm_state) { |
|
if (port && port->ops->pm) |
|
port->ops->pm(port, pm_state, state->pm_state); |
|
state->pm_state = pm_state; |
|
} |
|
} |
|
|
|
struct uart_match { |
|
struct uart_port *port; |
|
struct uart_driver *driver; |
|
}; |
|
|
|
static int serial_match_port(struct device *dev, void *data) |
|
{ |
|
struct uart_match *match = data; |
|
struct tty_driver *tty_drv = match->driver->tty_driver; |
|
dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) + |
|
match->port->line; |
|
|
|
return dev->devt == devt; /* Actually, only one tty per port */ |
|
} |
|
|
|
int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) |
|
{ |
|
struct uart_state *state = drv->state + uport->line; |
|
struct tty_port *port = &state->port; |
|
struct device *tty_dev; |
|
struct uart_match match = {uport, drv}; |
|
|
|
mutex_lock(&port->mutex); |
|
|
|
tty_dev = device_find_child(uport->dev, &match, serial_match_port); |
|
if (tty_dev && device_may_wakeup(tty_dev)) { |
|
enable_irq_wake(uport->irq); |
|
put_device(tty_dev); |
|
mutex_unlock(&port->mutex); |
|
return 0; |
|
} |
|
put_device(tty_dev); |
|
|
|
/* Nothing to do if the console is not suspending */ |
|
if (!console_suspend_enabled && uart_console(uport)) |
|
goto unlock; |
|
|
|
uport->suspended = 1; |
|
|
|
if (tty_port_initialized(port)) { |
|
const struct uart_ops *ops = uport->ops; |
|
int tries; |
|
|
|
tty_port_set_suspended(port, 1); |
|
tty_port_set_initialized(port, 0); |
|
|
|
spin_lock_irq(&uport->lock); |
|
ops->stop_tx(uport); |
|
ops->set_mctrl(uport, 0); |
|
ops->stop_rx(uport); |
|
spin_unlock_irq(&uport->lock); |
|
|
|
/* |
|
* Wait for the transmitter to empty. |
|
*/ |
|
for (tries = 3; !ops->tx_empty(uport) && tries; tries--) |
|
msleep(10); |
|
if (!tries) |
|
dev_err(uport->dev, "%s: Unable to drain transmitter\n", |
|
uport->name); |
|
|
|
ops->shutdown(uport); |
|
} |
|
|
|
/* |
|
* Disable the console device before suspending. |
|
*/ |
|
if (uart_console(uport)) |
|
console_stop(uport->cons); |
|
|
|
uart_change_pm(state, UART_PM_STATE_OFF); |
|
unlock: |
|
mutex_unlock(&port->mutex); |
|
|
|
return 0; |
|
} |
|
|
|
int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) |
|
{ |
|
struct uart_state *state = drv->state + uport->line; |
|
struct tty_port *port = &state->port; |
|
struct device *tty_dev; |
|
struct uart_match match = {uport, drv}; |
|
struct ktermios termios; |
|
|
|
mutex_lock(&port->mutex); |
|
|
|
tty_dev = device_find_child(uport->dev, &match, serial_match_port); |
|
if (!uport->suspended && device_may_wakeup(tty_dev)) { |
|
if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq)))) |
|
disable_irq_wake(uport->irq); |
|
put_device(tty_dev); |
|
mutex_unlock(&port->mutex); |
|
return 0; |
|
} |
|
put_device(tty_dev); |
|
uport->suspended = 0; |
|
|
|
/* |
|
* Re-enable the console device after suspending. |
|
*/ |
|
if (uart_console(uport)) { |
|
/* |
|
* First try to use the console cflag setting. |
|
*/ |
|
memset(&termios, 0, sizeof(struct ktermios)); |
|
termios.c_cflag = uport->cons->cflag; |
|
|
|
/* |
|
* If that's unset, use the tty termios setting. |
|
*/ |
|
if (port->tty && termios.c_cflag == 0) |
|
termios = port->tty->termios; |
|
|
|
if (console_suspend_enabled) |
|
uart_change_pm(state, UART_PM_STATE_ON); |
|
uport->ops->set_termios(uport, &termios, NULL); |
|
if (console_suspend_enabled) |
|
console_start(uport->cons); |
|
} |
|
|
|
if (tty_port_suspended(port)) { |
|
const struct uart_ops *ops = uport->ops; |
|
int ret; |
|
|
|
uart_change_pm(state, UART_PM_STATE_ON); |
|
spin_lock_irq(&uport->lock); |
|
ops->set_mctrl(uport, 0); |
|
spin_unlock_irq(&uport->lock); |
|
if (console_suspend_enabled || !uart_console(uport)) { |
|
/* Protected by port mutex for now */ |
|
struct tty_struct *tty = port->tty; |
|
|
|
ret = ops->startup(uport); |
|
if (ret == 0) { |
|
if (tty) |
|
uart_change_speed(tty, state, NULL); |
|
spin_lock_irq(&uport->lock); |
|
ops->set_mctrl(uport, uport->mctrl); |
|
ops->start_tx(uport); |
|
spin_unlock_irq(&uport->lock); |
|
tty_port_set_initialized(port, 1); |
|
} else { |
|
/* |
|
* Failed to resume - maybe hardware went away? |
|
* Clear the "initialized" flag so we won't try |
|
* to call the low level drivers shutdown method. |
|
*/ |
|
uart_shutdown(tty, state); |
|
} |
|
} |
|
|
|
tty_port_set_suspended(port, 0); |
|
} |
|
|
|
mutex_unlock(&port->mutex); |
|
|
|
return 0; |
|
} |
|
|
|
static inline void |
|
uart_report_port(struct uart_driver *drv, struct uart_port *port) |
|
{ |
|
char address[64]; |
|
|
|
switch (port->iotype) { |
|
case UPIO_PORT: |
|
snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase); |
|
break; |
|
case UPIO_HUB6: |
|
snprintf(address, sizeof(address), |
|
"I/O 0x%lx offset 0x%x", port->iobase, port->hub6); |
|
break; |
|
case UPIO_MEM: |
|
case UPIO_MEM16: |
|
case UPIO_MEM32: |
|
case UPIO_MEM32BE: |
|
case UPIO_AU: |
|
case UPIO_TSI: |
|
snprintf(address, sizeof(address), |
|
"MMIO 0x%llx", (unsigned long long)port->mapbase); |
|
break; |
|
default: |
|
strlcpy(address, "*unknown*", sizeof(address)); |
|
break; |
|
} |
|
|
|
pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n", |
|
port->dev ? dev_name(port->dev) : "", |
|
port->dev ? ": " : "", |
|
port->name, |
|
address, port->irq, port->uartclk / 16, uart_type(port)); |
|
} |
|
|
|
static void |
|
uart_configure_port(struct uart_driver *drv, struct uart_state *state, |
|
struct uart_port *port) |
|
{ |
|
unsigned int flags; |
|
|
|
/* |
|
* If there isn't a port here, don't do anything further. |
|
*/ |
|
if (!port->iobase && !port->mapbase && !port->membase) |
|
return; |
|
|
|
/* |
|
* Now do the auto configuration stuff. Note that config_port |
|
* is expected to claim the resources and map the port for us. |
|
*/ |
|
flags = 0; |
|
if (port->flags & UPF_AUTO_IRQ) |
|
flags |= UART_CONFIG_IRQ; |
|
if (port->flags & UPF_BOOT_AUTOCONF) { |
|
if (!(port->flags & UPF_FIXED_TYPE)) { |
|
port->type = PORT_UNKNOWN; |
|
flags |= UART_CONFIG_TYPE; |
|
} |
|
port->ops->config_port(port, flags); |
|
} |
|
|
|
if (port->type != PORT_UNKNOWN) { |
|
unsigned long flags; |
|
|
|
uart_report_port(drv, port); |
|
|
|
/* Power up port for set_mctrl() */ |
|
uart_change_pm(state, UART_PM_STATE_ON); |
|
|
|
/* |
|
* Ensure that the modem control lines are de-activated. |
|
* keep the DTR setting that is set in uart_set_options() |
|
* We probably don't need a spinlock around this, but |
|
*/ |
|
spin_lock_irqsave(&port->lock, flags); |
|
port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR); |
|
spin_unlock_irqrestore(&port->lock, flags); |
|
|
|
/* |
|
* If this driver supports console, and it hasn't been |
|
* successfully registered yet, try to re-register it. |
|
* It may be that the port was not available. |
|
*/ |
|
if (port->cons && !(port->cons->flags & CON_ENABLED)) |
|
register_console(port->cons); |
|
|
|
/* |
|
* Power down all ports by default, except the |
|
* console if we have one. |
|
*/ |
|
if (!uart_console(port)) |
|
uart_change_pm(state, UART_PM_STATE_OFF); |
|
} |
|
} |
|
|
|
#ifdef CONFIG_CONSOLE_POLL |
|
|
|
static int uart_poll_init(struct tty_driver *driver, int line, char *options) |
|
{ |
|
struct uart_driver *drv = driver->driver_state; |
|
struct uart_state *state = drv->state + line; |
|
struct tty_port *tport; |
|
struct uart_port *port; |
|
int baud = 9600; |
|
int bits = 8; |
|
int parity = 'n'; |
|
int flow = 'n'; |
|
int ret = 0; |
|
|
|
tport = &state->port; |
|
mutex_lock(&tport->mutex); |
|
|
|
port = uart_port_check(state); |
|
if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) { |
|
ret = -1; |
|
goto out; |
|
} |
|
|
|
if (port->ops->poll_init) { |
|
/* |
|
* We don't set initialized as we only initialized the hw, |
|
* e.g. state->xmit is still uninitialized. |
|
*/ |
|
if (!tty_port_initialized(tport)) |
|
ret = port->ops->poll_init(port); |
|
} |
|
|
|
if (!ret && options) { |
|
uart_parse_options(options, &baud, &parity, &bits, &flow); |
|
ret = uart_set_options(port, NULL, baud, parity, bits, flow); |
|
} |
|
out: |
|
mutex_unlock(&tport->mutex); |
|
return ret; |
|
} |
|
|
|
static int uart_poll_get_char(struct tty_driver *driver, int line) |
|
{ |
|
struct uart_driver *drv = driver->driver_state; |
|
struct uart_state *state = drv->state + line; |
|
struct uart_port *port; |
|
int ret = -1; |
|
|
|
port = uart_port_ref(state); |
|
if (port) { |
|
ret = port->ops->poll_get_char(port); |
|
uart_port_deref(port); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) |
|
{ |
|
struct uart_driver *drv = driver->driver_state; |
|
struct uart_state *state = drv->state + line; |
|
struct uart_port *port; |
|
|
|
port = uart_port_ref(state); |
|
if (!port) |
|
return; |
|
|
|
if (ch == '\n') |
|
port->ops->poll_put_char(port, '\r'); |
|
port->ops->poll_put_char(port, ch); |
|
uart_port_deref(port); |
|
} |
|
#endif |
|
|
|
static const struct tty_operations uart_ops = { |
|
.install = uart_install, |
|
.open = uart_open, |
|
.close = uart_close, |
|
.write = uart_write, |
|
.put_char = uart_put_char, |
|
.flush_chars = uart_flush_chars, |
|
.write_room = uart_write_room, |
|
.chars_in_buffer= uart_chars_in_buffer, |
|
.flush_buffer = uart_flush_buffer, |
|
.ioctl = uart_ioctl, |
|
.throttle = uart_throttle, |
|
.unthrottle = uart_unthrottle, |
|
.send_xchar = uart_send_xchar, |
|
.set_termios = uart_set_termios, |
|
.set_ldisc = uart_set_ldisc, |
|
.stop = uart_stop, |
|
.start = uart_start, |
|
.hangup = uart_hangup, |
|
.break_ctl = uart_break_ctl, |
|
.wait_until_sent= uart_wait_until_sent, |
|
#ifdef CONFIG_PROC_FS |
|
.proc_show = uart_proc_show, |
|
#endif |
|
.tiocmget = uart_tiocmget, |
|
.tiocmset = uart_tiocmset, |
|
.set_serial = uart_set_info_user, |
|
.get_serial = uart_get_info_user, |
|
.get_icount = uart_get_icount, |
|
#ifdef CONFIG_CONSOLE_POLL |
|
.poll_init = uart_poll_init, |
|
.poll_get_char = uart_poll_get_char, |
|
.poll_put_char = uart_poll_put_char, |
|
#endif |
|
}; |
|
|
|
static const struct tty_port_operations uart_port_ops = { |
|
.carrier_raised = uart_carrier_raised, |
|
.dtr_rts = uart_dtr_rts, |
|
.activate = uart_port_activate, |
|
.shutdown = uart_tty_port_shutdown, |
|
}; |
|
|
|
/** |
|
* uart_register_driver - register a driver with the uart core layer |
|
* @drv: low level driver structure |
|
* |
|
* Register a uart driver with the core driver. We in turn register |
|
* with the tty layer, and initialise the core driver per-port state. |
|
* |
|
* We have a proc file in /proc/tty/driver which is named after the |
|
* normal driver. |
|
* |
|
* drv->port should be NULL, and the per-port structures should be |
|
* registered using uart_add_one_port after this call has succeeded. |
|
*/ |
|
int uart_register_driver(struct uart_driver *drv) |
|
{ |
|
struct tty_driver *normal; |
|
int i, retval = -ENOMEM; |
|
|
|
BUG_ON(drv->state); |
|
|
|
/* |
|
* Maybe we should be using a slab cache for this, especially if |
|
* we have a large number of ports to handle. |
|
*/ |
|
drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL); |
|
if (!drv->state) |
|
goto out; |
|
|
|
normal = alloc_tty_driver(drv->nr); |
|
if (!normal) |
|
goto out_kfree; |
|
|
|
drv->tty_driver = normal; |
|
|
|
normal->driver_name = drv->driver_name; |
|
normal->name = drv->dev_name; |
|
normal->major = drv->major; |
|
normal->minor_start = drv->minor; |
|
normal->type = TTY_DRIVER_TYPE_SERIAL; |
|
normal->subtype = SERIAL_TYPE_NORMAL; |
|
normal->init_termios = tty_std_termios; |
|
normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL; |
|
normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600; |
|
normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; |
|
normal->driver_state = drv; |
|
tty_set_operations(normal, &uart_ops); |
|
|
|
/* |
|
* Initialise the UART state(s). |
|
*/ |
|
for (i = 0; i < drv->nr; i++) { |
|
struct uart_state *state = drv->state + i; |
|
struct tty_port *port = &state->port; |
|
|
|
tty_port_init(port); |
|
port->ops = &uart_port_ops; |
|
} |
|
|
|
retval = tty_register_driver(normal); |
|
if (retval >= 0) |
|
return retval; |
|
|
|
for (i = 0; i < drv->nr; i++) |
|
tty_port_destroy(&drv->state[i].port); |
|
put_tty_driver(normal); |
|
out_kfree: |
|
kfree(drv->state); |
|
out: |
|
return retval; |
|
} |
|
|
|
/** |
|
* uart_unregister_driver - remove a driver from the uart core layer |
|
* @drv: low level driver structure |
|
* |
|
* Remove all references to a driver from the core driver. The low |
|
* level driver must have removed all its ports via the |
|
* uart_remove_one_port() if it registered them with uart_add_one_port(). |
|
* (ie, drv->port == NULL) |
|
*/ |
|
void uart_unregister_driver(struct uart_driver *drv) |
|
{ |
|
struct tty_driver *p = drv->tty_driver; |
|
unsigned int i; |
|
|
|
tty_unregister_driver(p); |
|
put_tty_driver(p); |
|
for (i = 0; i < drv->nr; i++) |
|
tty_port_destroy(&drv->state[i].port); |
|
kfree(drv->state); |
|
drv->state = NULL; |
|
drv->tty_driver = NULL; |
|
} |
|
|
|
struct tty_driver *uart_console_device(struct console *co, int *index) |
|
{ |
|
struct uart_driver *p = co->data; |
|
*index = co->index; |
|
return p->tty_driver; |
|
} |
|
EXPORT_SYMBOL_GPL(uart_console_device); |
|
|
|
static ssize_t uartclk_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.baud_base * 16); |
|
} |
|
|
|
static ssize_t type_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.type); |
|
} |
|
|
|
static ssize_t line_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.line); |
|
} |
|
|
|
static ssize_t port_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
unsigned long ioaddr; |
|
|
|
uart_get_info(port, &tmp); |
|
ioaddr = tmp.port; |
|
if (HIGH_BITS_OFFSET) |
|
ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET; |
|
return sprintf(buf, "0x%lX\n", ioaddr); |
|
} |
|
|
|
static ssize_t irq_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.irq); |
|
} |
|
|
|
static ssize_t flags_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "0x%X\n", tmp.flags); |
|
} |
|
|
|
static ssize_t xmit_fifo_size_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.xmit_fifo_size); |
|
} |
|
|
|
static ssize_t close_delay_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.close_delay); |
|
} |
|
|
|
static ssize_t closing_wait_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.closing_wait); |
|
} |
|
|
|
static ssize_t custom_divisor_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.custom_divisor); |
|
} |
|
|
|
static ssize_t io_type_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.io_type); |
|
} |
|
|
|
static ssize_t iomem_base_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base); |
|
} |
|
|
|
static ssize_t iomem_reg_shift_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct serial_struct tmp; |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
|
|
uart_get_info(port, &tmp); |
|
return sprintf(buf, "%d\n", tmp.iomem_reg_shift); |
|
} |
|
|
|
static ssize_t console_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
struct uart_state *state = container_of(port, struct uart_state, port); |
|
struct uart_port *uport; |
|
bool console = false; |
|
|
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
if (uport) |
|
console = uart_console_enabled(uport); |
|
mutex_unlock(&port->mutex); |
|
|
|
return sprintf(buf, "%c\n", console ? 'Y' : 'N'); |
|
} |
|
|
|
static ssize_t console_store(struct device *dev, |
|
struct device_attribute *attr, const char *buf, size_t count) |
|
{ |
|
struct tty_port *port = dev_get_drvdata(dev); |
|
struct uart_state *state = container_of(port, struct uart_state, port); |
|
struct uart_port *uport; |
|
bool oldconsole, newconsole; |
|
int ret; |
|
|
|
ret = kstrtobool(buf, &newconsole); |
|
if (ret) |
|
return ret; |
|
|
|
mutex_lock(&port->mutex); |
|
uport = uart_port_check(state); |
|
if (uport) { |
|
oldconsole = uart_console_enabled(uport); |
|
if (oldconsole && !newconsole) { |
|
ret = unregister_console(uport->cons); |
|
} else if (!oldconsole && newconsole) { |
|
if (uart_console(uport)) { |
|
uport->console_reinit = 1; |
|
register_console(uport->cons); |
|
} else { |
|
ret = -ENOENT; |
|
} |
|
} |
|
} else { |
|
ret = -ENXIO; |
|
} |
|
mutex_unlock(&port->mutex); |
|
|
|
return ret < 0 ? ret : count; |
|
} |
|
|
|
static DEVICE_ATTR_RO(uartclk); |
|
static DEVICE_ATTR_RO(type); |
|
static DEVICE_ATTR_RO(line); |
|
static DEVICE_ATTR_RO(port); |
|
static DEVICE_ATTR_RO(irq); |
|
static DEVICE_ATTR_RO(flags); |
|
static DEVICE_ATTR_RO(xmit_fifo_size); |
|
static DEVICE_ATTR_RO(close_delay); |
|
static DEVICE_ATTR_RO(closing_wait); |
|
static DEVICE_ATTR_RO(custom_divisor); |
|
static DEVICE_ATTR_RO(io_type); |
|
static DEVICE_ATTR_RO(iomem_base); |
|
static DEVICE_ATTR_RO(iomem_reg_shift); |
|
static DEVICE_ATTR_RW(console); |
|
|
|
static struct attribute *tty_dev_attrs[] = { |
|
&dev_attr_uartclk.attr, |
|
&dev_attr_type.attr, |
|
&dev_attr_line.attr, |
|
&dev_attr_port.attr, |
|
&dev_attr_irq.attr, |
|
&dev_attr_flags.attr, |
|
&dev_attr_xmit_fifo_size.attr, |
|
&dev_attr_close_delay.attr, |
|
&dev_attr_closing_wait.attr, |
|
&dev_attr_custom_divisor.attr, |
|
&dev_attr_io_type.attr, |
|
&dev_attr_iomem_base.attr, |
|
&dev_attr_iomem_reg_shift.attr, |
|
&dev_attr_console.attr, |
|
NULL |
|
}; |
|
|
|
static const struct attribute_group tty_dev_attr_group = { |
|
.attrs = tty_dev_attrs, |
|
}; |
|
|
|
/** |
|
* uart_add_one_port - attach a driver-defined port structure |
|
* @drv: pointer to the uart low level driver structure for this port |
|
* @uport: uart port structure to use for this port. |
|
* |
|
* Context: task context, might sleep |
|
* |
|
* This allows the driver to register its own uart_port structure |
|
* with the core driver. The main purpose is to allow the low |
|
* level uart drivers to expand uart_port, rather than having yet |
|
* more levels of structures. |
|
*/ |
|
int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) |
|
{ |
|
struct uart_state *state; |
|
struct tty_port *port; |
|
int ret = 0; |
|
struct device *tty_dev; |
|
int num_groups; |
|
|
|
if (uport->line >= drv->nr) |
|
return -EINVAL; |
|
|
|
state = drv->state + uport->line; |
|
port = &state->port; |
|
|
|
mutex_lock(&port_mutex); |
|
mutex_lock(&port->mutex); |
|
if (state->uart_port) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
/* Link the port to the driver state table and vice versa */ |
|
atomic_set(&state->refcount, 1); |
|
init_waitqueue_head(&state->remove_wait); |
|
state->uart_port = uport; |
|
uport->state = state; |
|
|
|
state->pm_state = UART_PM_STATE_UNDEFINED; |
|
uport->cons = drv->cons; |
|
uport->minor = drv->tty_driver->minor_start + uport->line; |
|
uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name, |
|
drv->tty_driver->name_base + uport->line); |
|
if (!uport->name) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
/* |
|
* If this port is in use as a console then the spinlock is already |
|
* initialised. |
|
*/ |
|
if (!uart_console_enabled(uport)) |
|
uart_port_spin_lock_init(uport); |
|
|
|
if (uport->cons && uport->dev) |
|
of_console_check(uport->dev->of_node, uport->cons->name, uport->line); |
|
|
|
tty_port_link_device(port, drv->tty_driver, uport->line); |
|
uart_configure_port(drv, state, uport); |
|
|
|
port->console = uart_console(uport); |
|
|
|
num_groups = 2; |
|
if (uport->attr_group) |
|
num_groups++; |
|
|
|
uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups), |
|
GFP_KERNEL); |
|
if (!uport->tty_groups) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
uport->tty_groups[0] = &tty_dev_attr_group; |
|
if (uport->attr_group) |
|
uport->tty_groups[1] = uport->attr_group; |
|
|
|
/* |
|
* Register the port whether it's detected or not. This allows |
|
* setserial to be used to alter this port's parameters. |
|
*/ |
|
tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver, |
|
uport->line, uport->dev, port, uport->tty_groups); |
|
if (!IS_ERR(tty_dev)) { |
|
device_set_wakeup_capable(tty_dev, 1); |
|
} else { |
|
dev_err(uport->dev, "Cannot register tty device on line %d\n", |
|
uport->line); |
|
} |
|
|
|
/* |
|
* Ensure UPF_DEAD is not set. |
|
*/ |
|
uport->flags &= ~UPF_DEAD; |
|
|
|
out: |
|
mutex_unlock(&port->mutex); |
|
mutex_unlock(&port_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* uart_remove_one_port - detach a driver defined port structure |
|
* @drv: pointer to the uart low level driver structure for this port |
|
* @uport: uart port structure for this port |
|
* |
|
* Context: task context, might sleep |
|
* |
|
* This unhooks (and hangs up) the specified port structure from the |
|
* core driver. No further calls will be made to the low-level code |
|
* for this port. |
|
*/ |
|
int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) |
|
{ |
|
struct uart_state *state = drv->state + uport->line; |
|
struct tty_port *port = &state->port; |
|
struct uart_port *uart_port; |
|
struct tty_struct *tty; |
|
int ret = 0; |
|
|
|
mutex_lock(&port_mutex); |
|
|
|
/* |
|
* Mark the port "dead" - this prevents any opens from |
|
* succeeding while we shut down the port. |
|
*/ |
|
mutex_lock(&port->mutex); |
|
uart_port = uart_port_check(state); |
|
if (uart_port != uport) |
|
dev_alert(uport->dev, "Removing wrong port: %p != %p\n", |
|
uart_port, uport); |
|
|
|
if (!uart_port) { |
|
mutex_unlock(&port->mutex); |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
uport->flags |= UPF_DEAD; |
|
mutex_unlock(&port->mutex); |
|
|
|
/* |
|
* Remove the devices from the tty layer |
|
*/ |
|
tty_port_unregister_device(port, drv->tty_driver, uport->line); |
|
|
|
tty = tty_port_tty_get(port); |
|
if (tty) { |
|
tty_vhangup(port->tty); |
|
tty_kref_put(tty); |
|
} |
|
|
|
/* |
|
* If the port is used as a console, unregister it |
|
*/ |
|
if (uart_console(uport)) |
|
unregister_console(uport->cons); |
|
|
|
/* |
|
* Free the port IO and memory resources, if any. |
|
*/ |
|
if (uport->type != PORT_UNKNOWN && uport->ops->release_port) |
|
uport->ops->release_port(uport); |
|
kfree(uport->tty_groups); |
|
kfree(uport->name); |
|
|
|
/* |
|
* Indicate that there isn't a port here anymore. |
|
*/ |
|
uport->type = PORT_UNKNOWN; |
|
|
|
mutex_lock(&port->mutex); |
|
WARN_ON(atomic_dec_return(&state->refcount) < 0); |
|
wait_event(state->remove_wait, !atomic_read(&state->refcount)); |
|
state->uart_port = NULL; |
|
mutex_unlock(&port->mutex); |
|
out: |
|
mutex_unlock(&port_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Are the two ports equivalent? |
|
*/ |
|
int uart_match_port(struct uart_port *port1, struct uart_port *port2) |
|
{ |
|
if (port1->iotype != port2->iotype) |
|
return 0; |
|
|
|
switch (port1->iotype) { |
|
case UPIO_PORT: |
|
return (port1->iobase == port2->iobase); |
|
case UPIO_HUB6: |
|
return (port1->iobase == port2->iobase) && |
|
(port1->hub6 == port2->hub6); |
|
case UPIO_MEM: |
|
case UPIO_MEM16: |
|
case UPIO_MEM32: |
|
case UPIO_MEM32BE: |
|
case UPIO_AU: |
|
case UPIO_TSI: |
|
return (port1->mapbase == port2->mapbase); |
|
} |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(uart_match_port); |
|
|
|
/** |
|
* uart_handle_dcd_change - handle a change of carrier detect state |
|
* @uport: uart_port structure for the open port |
|
* @status: new carrier detect status, nonzero if active |
|
* |
|
* Caller must hold uport->lock |
|
*/ |
|
void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) |
|
{ |
|
struct tty_port *port = &uport->state->port; |
|
struct tty_struct *tty = port->tty; |
|
struct tty_ldisc *ld; |
|
|
|
lockdep_assert_held_once(&uport->lock); |
|
|
|
if (tty) { |
|
ld = tty_ldisc_ref(tty); |
|
if (ld) { |
|
if (ld->ops->dcd_change) |
|
ld->ops->dcd_change(tty, status); |
|
tty_ldisc_deref(ld); |
|
} |
|
} |
|
|
|
uport->icount.dcd++; |
|
|
|
if (uart_dcd_enabled(uport)) { |
|
if (status) |
|
wake_up_interruptible(&port->open_wait); |
|
else if (tty) |
|
tty_hangup(tty); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(uart_handle_dcd_change); |
|
|
|
/** |
|
* uart_handle_cts_change - handle a change of clear-to-send state |
|
* @uport: uart_port structure for the open port |
|
* @status: new clear to send status, nonzero if active |
|
* |
|
* Caller must hold uport->lock |
|
*/ |
|
void uart_handle_cts_change(struct uart_port *uport, unsigned int status) |
|
{ |
|
lockdep_assert_held_once(&uport->lock); |
|
|
|
uport->icount.cts++; |
|
|
|
if (uart_softcts_mode(uport)) { |
|
if (uport->hw_stopped) { |
|
if (status) { |
|
uport->hw_stopped = 0; |
|
uport->ops->start_tx(uport); |
|
uart_write_wakeup(uport); |
|
} |
|
} else { |
|
if (!status) { |
|
uport->hw_stopped = 1; |
|
uport->ops->stop_tx(uport); |
|
} |
|
} |
|
|
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(uart_handle_cts_change); |
|
|
|
/** |
|
* uart_insert_char - push a char to the uart layer |
|
* |
|
* User is responsible to call tty_flip_buffer_push when they are done with |
|
* insertion. |
|
* |
|
* @port: corresponding port |
|
* @status: state of the serial port RX buffer (LSR for 8250) |
|
* @overrun: mask of overrun bits in @status |
|
* @ch: character to push |
|
* @flag: flag for the character (see TTY_NORMAL and friends) |
|
*/ |
|
void uart_insert_char(struct uart_port *port, unsigned int status, |
|
unsigned int overrun, unsigned int ch, unsigned int flag) |
|
{ |
|
struct tty_port *tport = &port->state->port; |
|
|
|
if ((status & port->ignore_status_mask & ~overrun) == 0) |
|
if (tty_insert_flip_char(tport, ch, flag) == 0) |
|
++port->icount.buf_overrun; |
|
|
|
/* |
|
* Overrun is special. Since it's reported immediately, |
|
* it doesn't affect the current character. |
|
*/ |
|
if (status & ~port->ignore_status_mask & overrun) |
|
if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0) |
|
++port->icount.buf_overrun; |
|
} |
|
EXPORT_SYMBOL_GPL(uart_insert_char); |
|
|
|
#ifdef CONFIG_MAGIC_SYSRQ_SERIAL |
|
static const char sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE; |
|
|
|
static void uart_sysrq_on(struct work_struct *w) |
|
{ |
|
int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); |
|
|
|
sysrq_toggle_support(1); |
|
pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n", |
|
sysrq_toggle_seq_len, sysrq_toggle_seq); |
|
} |
|
static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on); |
|
|
|
/** |
|
* uart_try_toggle_sysrq - Enables SysRq from serial line |
|
* @port: uart_port structure where char(s) after BREAK met |
|
* @ch: new character in the sequence after received BREAK |
|
* |
|
* Enables magic SysRq when the required sequence is met on port |
|
* (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE). |
|
* |
|
* Returns false if @ch is out of enabling sequence and should be |
|
* handled some other way, true if @ch was consumed. |
|
*/ |
|
bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch) |
|
{ |
|
int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); |
|
|
|
if (!sysrq_toggle_seq_len) |
|
return false; |
|
|
|
BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX); |
|
if (sysrq_toggle_seq[port->sysrq_seq] != ch) { |
|
port->sysrq_seq = 0; |
|
return false; |
|
} |
|
|
|
if (++port->sysrq_seq < sysrq_toggle_seq_len) { |
|
port->sysrq = jiffies + SYSRQ_TIMEOUT; |
|
return true; |
|
} |
|
|
|
schedule_work(&sysrq_enable_work); |
|
|
|
port->sysrq = 0; |
|
return true; |
|
} |
|
EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq); |
|
#endif |
|
|
|
EXPORT_SYMBOL(uart_write_wakeup); |
|
EXPORT_SYMBOL(uart_register_driver); |
|
EXPORT_SYMBOL(uart_unregister_driver); |
|
EXPORT_SYMBOL(uart_suspend_port); |
|
EXPORT_SYMBOL(uart_resume_port); |
|
EXPORT_SYMBOL(uart_add_one_port); |
|
EXPORT_SYMBOL(uart_remove_one_port); |
|
|
|
/** |
|
* uart_get_rs485_mode() - retrieve rs485 properties for given uart |
|
* @port: uart device's target port |
|
* |
|
* This function implements the device tree binding described in |
|
* Documentation/devicetree/bindings/serial/rs485.txt. |
|
*/ |
|
int uart_get_rs485_mode(struct uart_port *port) |
|
{ |
|
struct serial_rs485 *rs485conf = &port->rs485; |
|
struct device *dev = port->dev; |
|
u32 rs485_delay[2]; |
|
int ret; |
|
|
|
ret = device_property_read_u32_array(dev, "rs485-rts-delay", |
|
rs485_delay, 2); |
|
if (!ret) { |
|
rs485conf->delay_rts_before_send = rs485_delay[0]; |
|
rs485conf->delay_rts_after_send = rs485_delay[1]; |
|
} else { |
|
rs485conf->delay_rts_before_send = 0; |
|
rs485conf->delay_rts_after_send = 0; |
|
} |
|
|
|
/* |
|
* Clear full-duplex and enabled flags, set RTS polarity to active high |
|
* to get to a defined state with the following properties: |
|
*/ |
|
rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED | |
|
SER_RS485_TERMINATE_BUS | |
|
SER_RS485_RTS_AFTER_SEND); |
|
rs485conf->flags |= SER_RS485_RTS_ON_SEND; |
|
|
|
if (device_property_read_bool(dev, "rs485-rx-during-tx")) |
|
rs485conf->flags |= SER_RS485_RX_DURING_TX; |
|
|
|
if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time")) |
|
rs485conf->flags |= SER_RS485_ENABLED; |
|
|
|
if (device_property_read_bool(dev, "rs485-rts-active-low")) { |
|
rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; |
|
rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; |
|
} |
|
|
|
/* |
|
* Disabling termination by default is the safe choice: Else if many |
|
* bus participants enable it, no communication is possible at all. |
|
* Works fine for short cables and users may enable for longer cables. |
|
*/ |
|
port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term", |
|
GPIOD_OUT_LOW); |
|
if (IS_ERR(port->rs485_term_gpio)) { |
|
ret = PTR_ERR(port->rs485_term_gpio); |
|
port->rs485_term_gpio = NULL; |
|
return dev_err_probe(dev, ret, "Cannot get rs485-term-gpios\n"); |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(uart_get_rs485_mode); |
|
|
|
MODULE_DESCRIPTION("Serial driver core"); |
|
MODULE_LICENSE("GPL");
|
|
|