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1183 lines
28 KiB
1183 lines
28 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* SDIO UART/GPS driver |
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* |
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* Based on drivers/serial/8250.c and drivers/serial/serial_core.c |
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* by Russell King. |
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* |
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* Author: Nicolas Pitre |
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* Created: June 15, 2007 |
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* Copyright: MontaVista Software, Inc. |
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*/ |
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|
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/* |
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* Note: Although this driver assumes a 16550A-like UART implementation, |
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* it is not possible to leverage the common 8250/16550 driver, nor the |
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* core UART infrastructure, as they assumes direct access to the hardware |
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* registers, often under a spinlock. This is not possible in the SDIO |
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* context as SDIO access functions must be able to sleep. |
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* |
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* Because we need to lock the SDIO host to ensure an exclusive access to |
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* the card, we simply rely on that lock to also prevent and serialize |
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* concurrent access to the same port. |
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*/ |
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|
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/sched.h> |
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#include <linux/mutex.h> |
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#include <linux/seq_file.h> |
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#include <linux/serial_reg.h> |
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#include <linux/circ_buf.h> |
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#include <linux/tty.h> |
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#include <linux/tty_flip.h> |
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#include <linux/kfifo.h> |
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#include <linux/slab.h> |
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|
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#include <linux/mmc/core.h> |
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#include <linux/mmc/card.h> |
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#include <linux/mmc/sdio_func.h> |
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#include <linux/mmc/sdio_ids.h> |
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|
|
|
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#define UART_NR 8 /* Number of UARTs this driver can handle */ |
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|
|
|
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#define FIFO_SIZE PAGE_SIZE |
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#define WAKEUP_CHARS 256 |
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|
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struct uart_icount { |
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__u32 cts; |
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__u32 dsr; |
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__u32 rng; |
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__u32 dcd; |
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__u32 rx; |
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__u32 tx; |
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__u32 frame; |
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__u32 overrun; |
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__u32 parity; |
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__u32 brk; |
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}; |
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|
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struct sdio_uart_port { |
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struct tty_port port; |
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unsigned int index; |
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struct sdio_func *func; |
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struct mutex func_lock; |
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struct task_struct *in_sdio_uart_irq; |
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unsigned int regs_offset; |
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struct kfifo xmit_fifo; |
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spinlock_t write_lock; |
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struct uart_icount icount; |
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unsigned int uartclk; |
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unsigned int mctrl; |
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unsigned int rx_mctrl; |
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unsigned int read_status_mask; |
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unsigned int ignore_status_mask; |
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unsigned char x_char; |
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unsigned char ier; |
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unsigned char lcr; |
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}; |
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|
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static struct sdio_uart_port *sdio_uart_table[UART_NR]; |
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static DEFINE_SPINLOCK(sdio_uart_table_lock); |
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|
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static int sdio_uart_add_port(struct sdio_uart_port *port) |
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{ |
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int index, ret = -EBUSY; |
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|
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mutex_init(&port->func_lock); |
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spin_lock_init(&port->write_lock); |
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if (kfifo_alloc(&port->xmit_fifo, FIFO_SIZE, GFP_KERNEL)) |
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return -ENOMEM; |
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|
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spin_lock(&sdio_uart_table_lock); |
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for (index = 0; index < UART_NR; index++) { |
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if (!sdio_uart_table[index]) { |
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port->index = index; |
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sdio_uart_table[index] = port; |
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ret = 0; |
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break; |
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} |
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} |
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spin_unlock(&sdio_uart_table_lock); |
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|
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return ret; |
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} |
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|
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static struct sdio_uart_port *sdio_uart_port_get(unsigned index) |
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{ |
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struct sdio_uart_port *port; |
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|
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if (index >= UART_NR) |
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return NULL; |
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|
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spin_lock(&sdio_uart_table_lock); |
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port = sdio_uart_table[index]; |
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if (port) |
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tty_port_get(&port->port); |
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spin_unlock(&sdio_uart_table_lock); |
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|
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return port; |
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} |
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|
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static void sdio_uart_port_put(struct sdio_uart_port *port) |
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{ |
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tty_port_put(&port->port); |
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} |
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|
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static void sdio_uart_port_remove(struct sdio_uart_port *port) |
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{ |
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struct sdio_func *func; |
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|
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spin_lock(&sdio_uart_table_lock); |
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sdio_uart_table[port->index] = NULL; |
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spin_unlock(&sdio_uart_table_lock); |
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|
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/* |
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* We're killing a port that potentially still is in use by |
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* the tty layer. Be careful to prevent any further access |
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* to the SDIO function and arrange for the tty layer to |
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* give up on that port ASAP. |
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* Beware: the lock ordering is critical. |
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*/ |
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mutex_lock(&port->port.mutex); |
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mutex_lock(&port->func_lock); |
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func = port->func; |
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sdio_claim_host(func); |
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port->func = NULL; |
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mutex_unlock(&port->func_lock); |
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/* tty_hangup is async so is this safe as is ?? */ |
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tty_port_tty_hangup(&port->port, false); |
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mutex_unlock(&port->port.mutex); |
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sdio_release_irq(func); |
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sdio_disable_func(func); |
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sdio_release_host(func); |
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|
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sdio_uart_port_put(port); |
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} |
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|
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static int sdio_uart_claim_func(struct sdio_uart_port *port) |
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{ |
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mutex_lock(&port->func_lock); |
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if (unlikely(!port->func)) { |
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mutex_unlock(&port->func_lock); |
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return -ENODEV; |
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} |
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if (likely(port->in_sdio_uart_irq != current)) |
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sdio_claim_host(port->func); |
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mutex_unlock(&port->func_lock); |
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return 0; |
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} |
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|
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static inline void sdio_uart_release_func(struct sdio_uart_port *port) |
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{ |
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if (likely(port->in_sdio_uart_irq != current)) |
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sdio_release_host(port->func); |
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} |
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|
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static inline unsigned int sdio_in(struct sdio_uart_port *port, int offset) |
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{ |
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unsigned char c; |
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c = sdio_readb(port->func, port->regs_offset + offset, NULL); |
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return c; |
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} |
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|
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static inline void sdio_out(struct sdio_uart_port *port, int offset, int value) |
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{ |
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sdio_writeb(port->func, value, port->regs_offset + offset, NULL); |
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} |
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|
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static unsigned int sdio_uart_get_mctrl(struct sdio_uart_port *port) |
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{ |
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unsigned char status; |
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unsigned int ret; |
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|
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/* FIXME: What stops this losing the delta bits and breaking |
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sdio_uart_check_modem_status ? */ |
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status = sdio_in(port, UART_MSR); |
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|
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ret = 0; |
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if (status & UART_MSR_DCD) |
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ret |= TIOCM_CAR; |
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if (status & UART_MSR_RI) |
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ret |= TIOCM_RNG; |
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if (status & UART_MSR_DSR) |
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ret |= TIOCM_DSR; |
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if (status & UART_MSR_CTS) |
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ret |= TIOCM_CTS; |
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return ret; |
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} |
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|
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static void sdio_uart_write_mctrl(struct sdio_uart_port *port, |
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unsigned int mctrl) |
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{ |
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unsigned char mcr = 0; |
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|
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if (mctrl & TIOCM_RTS) |
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mcr |= UART_MCR_RTS; |
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if (mctrl & TIOCM_DTR) |
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mcr |= UART_MCR_DTR; |
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if (mctrl & TIOCM_OUT1) |
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mcr |= UART_MCR_OUT1; |
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if (mctrl & TIOCM_OUT2) |
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mcr |= UART_MCR_OUT2; |
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if (mctrl & TIOCM_LOOP) |
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mcr |= UART_MCR_LOOP; |
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|
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sdio_out(port, UART_MCR, mcr); |
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} |
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|
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static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port, |
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unsigned int set, unsigned int clear) |
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{ |
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unsigned int old; |
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|
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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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sdio_uart_write_mctrl(port, port->mctrl); |
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} |
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|
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#define sdio_uart_set_mctrl(port, x) sdio_uart_update_mctrl(port, x, 0) |
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#define sdio_uart_clear_mctrl(port, x) sdio_uart_update_mctrl(port, 0, x) |
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|
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static void sdio_uart_change_speed(struct sdio_uart_port *port, |
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struct ktermios *termios, |
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struct ktermios *old) |
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{ |
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unsigned char cval, fcr = 0; |
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unsigned int baud, quot; |
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|
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switch (termios->c_cflag & CSIZE) { |
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case CS5: |
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cval = UART_LCR_WLEN5; |
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break; |
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case CS6: |
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cval = UART_LCR_WLEN6; |
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break; |
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case CS7: |
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cval = UART_LCR_WLEN7; |
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break; |
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default: |
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case CS8: |
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cval = UART_LCR_WLEN8; |
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break; |
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} |
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|
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if (termios->c_cflag & CSTOPB) |
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cval |= UART_LCR_STOP; |
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if (termios->c_cflag & PARENB) |
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cval |= UART_LCR_PARITY; |
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if (!(termios->c_cflag & PARODD)) |
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cval |= UART_LCR_EPAR; |
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|
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for (;;) { |
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baud = tty_termios_baud_rate(termios); |
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if (baud == 0) |
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baud = 9600; /* Special case: B0 rate. */ |
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if (baud <= port->uartclk) |
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break; |
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/* |
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* Oops, the quotient was zero. Try again with the old |
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* baud rate if possible, otherwise default to 9600. |
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*/ |
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termios->c_cflag &= ~CBAUD; |
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if (old) { |
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termios->c_cflag |= old->c_cflag & CBAUD; |
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old = NULL; |
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} else |
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termios->c_cflag |= B9600; |
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} |
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quot = (2 * port->uartclk + baud) / (2 * baud); |
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|
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if (baud < 2400) |
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fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1; |
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else |
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fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10; |
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|
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port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR; |
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if (termios->c_iflag & INPCK) |
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port->read_status_mask |= UART_LSR_FE | UART_LSR_PE; |
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if (termios->c_iflag & (BRKINT | PARMRK)) |
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port->read_status_mask |= UART_LSR_BI; |
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|
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/* |
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* Characters to ignore |
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*/ |
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port->ignore_status_mask = 0; |
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if (termios->c_iflag & IGNPAR) |
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port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE; |
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if (termios->c_iflag & IGNBRK) { |
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port->ignore_status_mask |= UART_LSR_BI; |
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/* |
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* If we're ignoring parity and break indicators, |
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* ignore overruns too (for real raw support). |
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*/ |
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if (termios->c_iflag & IGNPAR) |
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port->ignore_status_mask |= UART_LSR_OE; |
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} |
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/* |
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* ignore all characters if CREAD is not set |
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*/ |
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if ((termios->c_cflag & CREAD) == 0) |
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port->ignore_status_mask |= UART_LSR_DR; |
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|
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/* |
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* CTS flow control flag and modem status interrupts |
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*/ |
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port->ier &= ~UART_IER_MSI; |
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if ((termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL)) |
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port->ier |= UART_IER_MSI; |
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port->lcr = cval; |
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sdio_out(port, UART_IER, port->ier); |
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sdio_out(port, UART_LCR, cval | UART_LCR_DLAB); |
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sdio_out(port, UART_DLL, quot & 0xff); |
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sdio_out(port, UART_DLM, quot >> 8); |
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sdio_out(port, UART_LCR, cval); |
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sdio_out(port, UART_FCR, fcr); |
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|
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sdio_uart_write_mctrl(port, port->mctrl); |
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} |
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static void sdio_uart_start_tx(struct sdio_uart_port *port) |
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{ |
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if (!(port->ier & UART_IER_THRI)) { |
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port->ier |= UART_IER_THRI; |
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sdio_out(port, UART_IER, port->ier); |
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} |
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} |
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|
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static void sdio_uart_stop_tx(struct sdio_uart_port *port) |
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{ |
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if (port->ier & UART_IER_THRI) { |
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port->ier &= ~UART_IER_THRI; |
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sdio_out(port, UART_IER, port->ier); |
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} |
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} |
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|
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static void sdio_uart_stop_rx(struct sdio_uart_port *port) |
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{ |
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port->ier &= ~UART_IER_RLSI; |
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port->read_status_mask &= ~UART_LSR_DR; |
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sdio_out(port, UART_IER, port->ier); |
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} |
|
|
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static void sdio_uart_receive_chars(struct sdio_uart_port *port, |
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unsigned int *status) |
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{ |
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unsigned int ch, flag; |
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int max_count = 256; |
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|
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do { |
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ch = sdio_in(port, UART_RX); |
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flag = TTY_NORMAL; |
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port->icount.rx++; |
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|
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if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE | |
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UART_LSR_FE | UART_LSR_OE))) { |
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/* |
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* For statistics only |
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*/ |
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if (*status & UART_LSR_BI) { |
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*status &= ~(UART_LSR_FE | UART_LSR_PE); |
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port->icount.brk++; |
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} else if (*status & UART_LSR_PE) |
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port->icount.parity++; |
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else if (*status & UART_LSR_FE) |
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port->icount.frame++; |
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if (*status & UART_LSR_OE) |
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port->icount.overrun++; |
|
|
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/* |
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* Mask off conditions which should be ignored. |
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*/ |
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*status &= port->read_status_mask; |
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if (*status & UART_LSR_BI) |
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flag = TTY_BREAK; |
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else if (*status & UART_LSR_PE) |
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flag = TTY_PARITY; |
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else if (*status & UART_LSR_FE) |
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flag = TTY_FRAME; |
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} |
|
|
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if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0) |
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tty_insert_flip_char(&port->port, ch, flag); |
|
|
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/* |
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* Overrun is special. Since it's reported immediately, |
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* it doesn't affect the current character. |
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*/ |
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if (*status & ~port->ignore_status_mask & UART_LSR_OE) |
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tty_insert_flip_char(&port->port, 0, TTY_OVERRUN); |
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|
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*status = sdio_in(port, UART_LSR); |
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} while ((*status & UART_LSR_DR) && (max_count-- > 0)); |
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|
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tty_flip_buffer_push(&port->port); |
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} |
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|
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static void sdio_uart_transmit_chars(struct sdio_uart_port *port) |
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{ |
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struct kfifo *xmit = &port->xmit_fifo; |
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int count; |
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struct tty_struct *tty; |
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u8 iobuf[16]; |
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int len; |
|
|
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if (port->x_char) { |
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sdio_out(port, UART_TX, port->x_char); |
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port->icount.tx++; |
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port->x_char = 0; |
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return; |
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} |
|
|
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tty = tty_port_tty_get(&port->port); |
|
|
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if (tty == NULL || !kfifo_len(xmit) || |
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tty->stopped || tty->hw_stopped) { |
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sdio_uart_stop_tx(port); |
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tty_kref_put(tty); |
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return; |
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} |
|
|
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len = kfifo_out_locked(xmit, iobuf, 16, &port->write_lock); |
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for (count = 0; count < len; count++) { |
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sdio_out(port, UART_TX, iobuf[count]); |
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port->icount.tx++; |
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} |
|
|
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len = kfifo_len(xmit); |
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if (len < WAKEUP_CHARS) { |
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tty_wakeup(tty); |
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if (len == 0) |
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sdio_uart_stop_tx(port); |
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} |
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tty_kref_put(tty); |
|
} |
|
|
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static void sdio_uart_check_modem_status(struct sdio_uart_port *port) |
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{ |
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int status; |
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struct tty_struct *tty; |
|
|
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status = sdio_in(port, UART_MSR); |
|
|
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if ((status & UART_MSR_ANY_DELTA) == 0) |
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return; |
|
|
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if (status & UART_MSR_TERI) |
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port->icount.rng++; |
|
if (status & UART_MSR_DDSR) |
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port->icount.dsr++; |
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if (status & UART_MSR_DDCD) { |
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port->icount.dcd++; |
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/* DCD raise - wake for open */ |
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if (status & UART_MSR_DCD) |
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wake_up_interruptible(&port->port.open_wait); |
|
else { |
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/* DCD drop - hang up if tty attached */ |
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tty_port_tty_hangup(&port->port, false); |
|
} |
|
} |
|
if (status & UART_MSR_DCTS) { |
|
port->icount.cts++; |
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tty = tty_port_tty_get(&port->port); |
|
if (tty && C_CRTSCTS(tty)) { |
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int cts = (status & UART_MSR_CTS); |
|
if (tty->hw_stopped) { |
|
if (cts) { |
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tty->hw_stopped = 0; |
|
sdio_uart_start_tx(port); |
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tty_wakeup(tty); |
|
} |
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} else { |
|
if (!cts) { |
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tty->hw_stopped = 1; |
|
sdio_uart_stop_tx(port); |
|
} |
|
} |
|
} |
|
tty_kref_put(tty); |
|
} |
|
} |
|
|
|
/* |
|
* This handles the interrupt from one port. |
|
*/ |
|
static void sdio_uart_irq(struct sdio_func *func) |
|
{ |
|
struct sdio_uart_port *port = sdio_get_drvdata(func); |
|
unsigned int iir, lsr; |
|
|
|
/* |
|
* In a few places sdio_uart_irq() is called directly instead of |
|
* waiting for the actual interrupt to be raised and the SDIO IRQ |
|
* thread scheduled in order to reduce latency. However, some |
|
* interaction with the tty core may end up calling us back |
|
* (serial echo, flow control, etc.) through those same places |
|
* causing undesirable effects. Let's stop the recursion here. |
|
*/ |
|
if (unlikely(port->in_sdio_uart_irq == current)) |
|
return; |
|
|
|
iir = sdio_in(port, UART_IIR); |
|
if (iir & UART_IIR_NO_INT) |
|
return; |
|
|
|
port->in_sdio_uart_irq = current; |
|
lsr = sdio_in(port, UART_LSR); |
|
if (lsr & UART_LSR_DR) |
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sdio_uart_receive_chars(port, &lsr); |
|
sdio_uart_check_modem_status(port); |
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if (lsr & UART_LSR_THRE) |
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sdio_uart_transmit_chars(port); |
|
port->in_sdio_uart_irq = NULL; |
|
} |
|
|
|
static int uart_carrier_raised(struct tty_port *tport) |
|
{ |
|
struct sdio_uart_port *port = |
|
container_of(tport, struct sdio_uart_port, port); |
|
unsigned int ret = sdio_uart_claim_func(port); |
|
if (ret) /* Missing hardware shouldn't block for carrier */ |
|
return 1; |
|
ret = sdio_uart_get_mctrl(port); |
|
sdio_uart_release_func(port); |
|
if (ret & TIOCM_CAR) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
/** |
|
* uart_dtr_rts - port helper to set uart signals |
|
* @tport: tty port to be updated |
|
* @onoff: set to turn on DTR/RTS |
|
* |
|
* Called by the tty port helpers when the modem signals need to be |
|
* adjusted during an open, close and hangup. |
|
*/ |
|
|
|
static void uart_dtr_rts(struct tty_port *tport, int onoff) |
|
{ |
|
struct sdio_uart_port *port = |
|
container_of(tport, struct sdio_uart_port, port); |
|
int ret = sdio_uart_claim_func(port); |
|
if (ret) |
|
return; |
|
if (onoff == 0) |
|
sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS); |
|
else |
|
sdio_uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS); |
|
sdio_uart_release_func(port); |
|
} |
|
|
|
/** |
|
* sdio_uart_activate - start up hardware |
|
* @tport: tty port to activate |
|
* @tty: tty bound to this port |
|
* |
|
* Activate a tty port. The port locking guarantees us this will be |
|
* run exactly once per set of opens, and if successful will see the |
|
* shutdown method run exactly once to match. Start up and shutdown are |
|
* protected from each other by the internal locking and will not run |
|
* at the same time even during a hangup event. |
|
* |
|
* If we successfully start up the port we take an extra kref as we |
|
* will keep it around until shutdown when the kref is dropped. |
|
*/ |
|
|
|
static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty) |
|
{ |
|
struct sdio_uart_port *port = |
|
container_of(tport, struct sdio_uart_port, port); |
|
int ret; |
|
|
|
/* |
|
* Set the TTY IO error marker - we will only clear this |
|
* once we have successfully opened the port. |
|
*/ |
|
set_bit(TTY_IO_ERROR, &tty->flags); |
|
|
|
kfifo_reset(&port->xmit_fifo); |
|
|
|
ret = sdio_uart_claim_func(port); |
|
if (ret) |
|
return ret; |
|
ret = sdio_enable_func(port->func); |
|
if (ret) |
|
goto err1; |
|
ret = sdio_claim_irq(port->func, sdio_uart_irq); |
|
if (ret) |
|
goto err2; |
|
|
|
/* |
|
* Clear the FIFO buffers and disable them. |
|
* (they will be reenabled in sdio_change_speed()) |
|
*/ |
|
sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO); |
|
sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO | |
|
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); |
|
sdio_out(port, UART_FCR, 0); |
|
|
|
/* |
|
* Clear the interrupt registers. |
|
*/ |
|
(void) sdio_in(port, UART_LSR); |
|
(void) sdio_in(port, UART_RX); |
|
(void) sdio_in(port, UART_IIR); |
|
(void) sdio_in(port, UART_MSR); |
|
|
|
/* |
|
* Now, initialize the UART |
|
*/ |
|
sdio_out(port, UART_LCR, UART_LCR_WLEN8); |
|
|
|
port->ier = UART_IER_RLSI|UART_IER_RDI|UART_IER_RTOIE|UART_IER_UUE; |
|
port->mctrl = TIOCM_OUT2; |
|
|
|
sdio_uart_change_speed(port, &tty->termios, NULL); |
|
|
|
if (C_BAUD(tty)) |
|
sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR); |
|
|
|
if (C_CRTSCTS(tty)) |
|
if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) |
|
tty->hw_stopped = 1; |
|
|
|
clear_bit(TTY_IO_ERROR, &tty->flags); |
|
|
|
/* Kick the IRQ handler once while we're still holding the host lock */ |
|
sdio_uart_irq(port->func); |
|
|
|
sdio_uart_release_func(port); |
|
return 0; |
|
|
|
err2: |
|
sdio_disable_func(port->func); |
|
err1: |
|
sdio_uart_release_func(port); |
|
return ret; |
|
} |
|
|
|
/** |
|
* sdio_uart_shutdown - stop hardware |
|
* @tport: tty port to shut down |
|
* |
|
* Deactivate a tty port. The port locking guarantees us this will be |
|
* run only if a successful matching activate already ran. The two are |
|
* protected from each other by the internal locking and will not run |
|
* at the same time even during a hangup event. |
|
*/ |
|
|
|
static void sdio_uart_shutdown(struct tty_port *tport) |
|
{ |
|
struct sdio_uart_port *port = |
|
container_of(tport, struct sdio_uart_port, port); |
|
int ret; |
|
|
|
ret = sdio_uart_claim_func(port); |
|
if (ret) |
|
return; |
|
|
|
sdio_uart_stop_rx(port); |
|
|
|
/* Disable interrupts from this port */ |
|
sdio_release_irq(port->func); |
|
port->ier = 0; |
|
sdio_out(port, UART_IER, 0); |
|
|
|
sdio_uart_clear_mctrl(port, TIOCM_OUT2); |
|
|
|
/* Disable break condition and FIFOs. */ |
|
port->lcr &= ~UART_LCR_SBC; |
|
sdio_out(port, UART_LCR, port->lcr); |
|
sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO | |
|
UART_FCR_CLEAR_RCVR | |
|
UART_FCR_CLEAR_XMIT); |
|
sdio_out(port, UART_FCR, 0); |
|
|
|
sdio_disable_func(port->func); |
|
|
|
sdio_uart_release_func(port); |
|
} |
|
|
|
static void sdio_uart_port_destroy(struct tty_port *tport) |
|
{ |
|
struct sdio_uart_port *port = |
|
container_of(tport, struct sdio_uart_port, port); |
|
kfifo_free(&port->xmit_fifo); |
|
kfree(port); |
|
} |
|
|
|
/** |
|
* sdio_uart_install - install method |
|
* @driver: the driver in use (sdio_uart in our case) |
|
* @tty: the tty being bound |
|
* |
|
* Look up and bind the tty and the driver together. Initialize |
|
* any needed private data (in our case the termios) |
|
*/ |
|
|
|
static int sdio_uart_install(struct tty_driver *driver, struct tty_struct *tty) |
|
{ |
|
int idx = tty->index; |
|
struct sdio_uart_port *port = sdio_uart_port_get(idx); |
|
int ret = tty_standard_install(driver, tty); |
|
|
|
if (ret == 0) |
|
/* This is the ref sdio_uart_port get provided */ |
|
tty->driver_data = port; |
|
else |
|
sdio_uart_port_put(port); |
|
return ret; |
|
} |
|
|
|
/** |
|
* sdio_uart_cleanup - called on the last tty kref drop |
|
* @tty: the tty being destroyed |
|
* |
|
* Called asynchronously when the last reference to the tty is dropped. |
|
* We cannot destroy the tty->driver_data port kref until this point |
|
*/ |
|
|
|
static void sdio_uart_cleanup(struct tty_struct *tty) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
tty->driver_data = NULL; /* Bug trap */ |
|
sdio_uart_port_put(port); |
|
} |
|
|
|
/* |
|
* Open/close/hangup is now entirely boilerplate |
|
*/ |
|
|
|
static int sdio_uart_open(struct tty_struct *tty, struct file *filp) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
return tty_port_open(&port->port, tty, filp); |
|
} |
|
|
|
static void sdio_uart_close(struct tty_struct *tty, struct file * filp) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
tty_port_close(&port->port, tty, filp); |
|
} |
|
|
|
static void sdio_uart_hangup(struct tty_struct *tty) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
tty_port_hangup(&port->port); |
|
} |
|
|
|
static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf, |
|
int count) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
int ret; |
|
|
|
if (!port->func) |
|
return -ENODEV; |
|
|
|
ret = kfifo_in_locked(&port->xmit_fifo, buf, count, &port->write_lock); |
|
if (!(port->ier & UART_IER_THRI)) { |
|
int err = sdio_uart_claim_func(port); |
|
if (!err) { |
|
sdio_uart_start_tx(port); |
|
sdio_uart_irq(port->func); |
|
sdio_uart_release_func(port); |
|
} else |
|
ret = err; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int sdio_uart_write_room(struct tty_struct *tty) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
return FIFO_SIZE - kfifo_len(&port->xmit_fifo); |
|
} |
|
|
|
static int sdio_uart_chars_in_buffer(struct tty_struct *tty) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
return kfifo_len(&port->xmit_fifo); |
|
} |
|
|
|
static void sdio_uart_send_xchar(struct tty_struct *tty, char ch) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
|
|
port->x_char = ch; |
|
if (ch && !(port->ier & UART_IER_THRI)) { |
|
if (sdio_uart_claim_func(port) != 0) |
|
return; |
|
sdio_uart_start_tx(port); |
|
sdio_uart_irq(port->func); |
|
sdio_uart_release_func(port); |
|
} |
|
} |
|
|
|
static void sdio_uart_throttle(struct tty_struct *tty) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
|
|
if (!I_IXOFF(tty) && !C_CRTSCTS(tty)) |
|
return; |
|
|
|
if (sdio_uart_claim_func(port) != 0) |
|
return; |
|
|
|
if (I_IXOFF(tty)) { |
|
port->x_char = STOP_CHAR(tty); |
|
sdio_uart_start_tx(port); |
|
} |
|
|
|
if (C_CRTSCTS(tty)) |
|
sdio_uart_clear_mctrl(port, TIOCM_RTS); |
|
|
|
sdio_uart_irq(port->func); |
|
sdio_uart_release_func(port); |
|
} |
|
|
|
static void sdio_uart_unthrottle(struct tty_struct *tty) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
|
|
if (!I_IXOFF(tty) && !C_CRTSCTS(tty)) |
|
return; |
|
|
|
if (sdio_uart_claim_func(port) != 0) |
|
return; |
|
|
|
if (I_IXOFF(tty)) { |
|
if (port->x_char) { |
|
port->x_char = 0; |
|
} else { |
|
port->x_char = START_CHAR(tty); |
|
sdio_uart_start_tx(port); |
|
} |
|
} |
|
|
|
if (C_CRTSCTS(tty)) |
|
sdio_uart_set_mctrl(port, TIOCM_RTS); |
|
|
|
sdio_uart_irq(port->func); |
|
sdio_uart_release_func(port); |
|
} |
|
|
|
static void sdio_uart_set_termios(struct tty_struct *tty, |
|
struct ktermios *old_termios) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
unsigned int cflag = tty->termios.c_cflag; |
|
|
|
if (sdio_uart_claim_func(port) != 0) |
|
return; |
|
|
|
sdio_uart_change_speed(port, &tty->termios, old_termios); |
|
|
|
/* Handle transition to B0 status */ |
|
if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) |
|
sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR); |
|
|
|
/* Handle transition away from B0 status */ |
|
if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { |
|
unsigned int mask = TIOCM_DTR; |
|
if (!(cflag & CRTSCTS) || !tty_throttled(tty)) |
|
mask |= TIOCM_RTS; |
|
sdio_uart_set_mctrl(port, mask); |
|
} |
|
|
|
/* Handle turning off CRTSCTS */ |
|
if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) { |
|
tty->hw_stopped = 0; |
|
sdio_uart_start_tx(port); |
|
} |
|
|
|
/* Handle turning on CRTSCTS */ |
|
if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) { |
|
if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) { |
|
tty->hw_stopped = 1; |
|
sdio_uart_stop_tx(port); |
|
} |
|
} |
|
|
|
sdio_uart_release_func(port); |
|
} |
|
|
|
static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
int result; |
|
|
|
result = sdio_uart_claim_func(port); |
|
if (result != 0) |
|
return result; |
|
|
|
if (break_state == -1) |
|
port->lcr |= UART_LCR_SBC; |
|
else |
|
port->lcr &= ~UART_LCR_SBC; |
|
sdio_out(port, UART_LCR, port->lcr); |
|
|
|
sdio_uart_release_func(port); |
|
return 0; |
|
} |
|
|
|
static int sdio_uart_tiocmget(struct tty_struct *tty) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
int result; |
|
|
|
result = sdio_uart_claim_func(port); |
|
if (!result) { |
|
result = port->mctrl | sdio_uart_get_mctrl(port); |
|
sdio_uart_release_func(port); |
|
} |
|
|
|
return result; |
|
} |
|
|
|
static int sdio_uart_tiocmset(struct tty_struct *tty, |
|
unsigned int set, unsigned int clear) |
|
{ |
|
struct sdio_uart_port *port = tty->driver_data; |
|
int result; |
|
|
|
result = sdio_uart_claim_func(port); |
|
if (!result) { |
|
sdio_uart_update_mctrl(port, set, clear); |
|
sdio_uart_release_func(port); |
|
} |
|
|
|
return result; |
|
} |
|
|
|
static int sdio_uart_proc_show(struct seq_file *m, void *v) |
|
{ |
|
int i; |
|
|
|
seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", |
|
"", "", ""); |
|
for (i = 0; i < UART_NR; i++) { |
|
struct sdio_uart_port *port = sdio_uart_port_get(i); |
|
if (port) { |
|
seq_printf(m, "%d: uart:SDIO", i); |
|
if (capable(CAP_SYS_ADMIN)) { |
|
seq_printf(m, " tx:%d rx:%d", |
|
port->icount.tx, port->icount.rx); |
|
if (port->icount.frame) |
|
seq_printf(m, " fe:%d", |
|
port->icount.frame); |
|
if (port->icount.parity) |
|
seq_printf(m, " pe:%d", |
|
port->icount.parity); |
|
if (port->icount.brk) |
|
seq_printf(m, " brk:%d", |
|
port->icount.brk); |
|
if (port->icount.overrun) |
|
seq_printf(m, " oe:%d", |
|
port->icount.overrun); |
|
if (port->icount.cts) |
|
seq_printf(m, " cts:%d", |
|
port->icount.cts); |
|
if (port->icount.dsr) |
|
seq_printf(m, " dsr:%d", |
|
port->icount.dsr); |
|
if (port->icount.rng) |
|
seq_printf(m, " rng:%d", |
|
port->icount.rng); |
|
if (port->icount.dcd) |
|
seq_printf(m, " dcd:%d", |
|
port->icount.dcd); |
|
} |
|
sdio_uart_port_put(port); |
|
seq_putc(m, '\n'); |
|
} |
|
} |
|
return 0; |
|
} |
|
|
|
static const struct tty_port_operations sdio_uart_port_ops = { |
|
.dtr_rts = uart_dtr_rts, |
|
.carrier_raised = uart_carrier_raised, |
|
.shutdown = sdio_uart_shutdown, |
|
.activate = sdio_uart_activate, |
|
.destruct = sdio_uart_port_destroy, |
|
}; |
|
|
|
static const struct tty_operations sdio_uart_ops = { |
|
.open = sdio_uart_open, |
|
.close = sdio_uart_close, |
|
.write = sdio_uart_write, |
|
.write_room = sdio_uart_write_room, |
|
.chars_in_buffer = sdio_uart_chars_in_buffer, |
|
.send_xchar = sdio_uart_send_xchar, |
|
.throttle = sdio_uart_throttle, |
|
.unthrottle = sdio_uart_unthrottle, |
|
.set_termios = sdio_uart_set_termios, |
|
.hangup = sdio_uart_hangup, |
|
.break_ctl = sdio_uart_break_ctl, |
|
.tiocmget = sdio_uart_tiocmget, |
|
.tiocmset = sdio_uart_tiocmset, |
|
.install = sdio_uart_install, |
|
.cleanup = sdio_uart_cleanup, |
|
.proc_show = sdio_uart_proc_show, |
|
}; |
|
|
|
static struct tty_driver *sdio_uart_tty_driver; |
|
|
|
static int sdio_uart_probe(struct sdio_func *func, |
|
const struct sdio_device_id *id) |
|
{ |
|
struct sdio_uart_port *port; |
|
int ret; |
|
|
|
port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL); |
|
if (!port) |
|
return -ENOMEM; |
|
|
|
if (func->class == SDIO_CLASS_UART) { |
|
pr_warn("%s: need info on UART class basic setup\n", |
|
sdio_func_id(func)); |
|
kfree(port); |
|
return -ENOSYS; |
|
} else if (func->class == SDIO_CLASS_GPS) { |
|
/* |
|
* We need tuple 0x91. It contains SUBTPL_SIOREG |
|
* and SUBTPL_RCVCAPS. |
|
*/ |
|
struct sdio_func_tuple *tpl; |
|
for (tpl = func->tuples; tpl; tpl = tpl->next) { |
|
if (tpl->code != 0x91) |
|
continue; |
|
if (tpl->size < 10) |
|
continue; |
|
if (tpl->data[1] == 0) /* SUBTPL_SIOREG */ |
|
break; |
|
} |
|
if (!tpl) { |
|
pr_warn("%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n", |
|
sdio_func_id(func)); |
|
kfree(port); |
|
return -EINVAL; |
|
} |
|
pr_debug("%s: Register ID = 0x%02x, Exp ID = 0x%02x\n", |
|
sdio_func_id(func), tpl->data[2], tpl->data[3]); |
|
port->regs_offset = (tpl->data[4] << 0) | |
|
(tpl->data[5] << 8) | |
|
(tpl->data[6] << 16); |
|
pr_debug("%s: regs offset = 0x%x\n", |
|
sdio_func_id(func), port->regs_offset); |
|
port->uartclk = tpl->data[7] * 115200; |
|
if (port->uartclk == 0) |
|
port->uartclk = 115200; |
|
pr_debug("%s: clk %d baudcode %u 4800-div %u\n", |
|
sdio_func_id(func), port->uartclk, |
|
tpl->data[7], tpl->data[8] | (tpl->data[9] << 8)); |
|
} else { |
|
kfree(port); |
|
return -EINVAL; |
|
} |
|
|
|
port->func = func; |
|
sdio_set_drvdata(func, port); |
|
tty_port_init(&port->port); |
|
port->port.ops = &sdio_uart_port_ops; |
|
|
|
ret = sdio_uart_add_port(port); |
|
if (ret) { |
|
kfree(port); |
|
} else { |
|
struct device *dev; |
|
dev = tty_port_register_device(&port->port, |
|
sdio_uart_tty_driver, port->index, &func->dev); |
|
if (IS_ERR(dev)) { |
|
sdio_uart_port_remove(port); |
|
ret = PTR_ERR(dev); |
|
} |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static void sdio_uart_remove(struct sdio_func *func) |
|
{ |
|
struct sdio_uart_port *port = sdio_get_drvdata(func); |
|
|
|
tty_unregister_device(sdio_uart_tty_driver, port->index); |
|
sdio_uart_port_remove(port); |
|
} |
|
|
|
static const struct sdio_device_id sdio_uart_ids[] = { |
|
{ SDIO_DEVICE_CLASS(SDIO_CLASS_UART) }, |
|
{ SDIO_DEVICE_CLASS(SDIO_CLASS_GPS) }, |
|
{ /* end: all zeroes */ }, |
|
}; |
|
|
|
MODULE_DEVICE_TABLE(sdio, sdio_uart_ids); |
|
|
|
static struct sdio_driver sdio_uart_driver = { |
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.probe = sdio_uart_probe, |
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.remove = sdio_uart_remove, |
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.name = "sdio_uart", |
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.id_table = sdio_uart_ids, |
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}; |
|
|
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static int __init sdio_uart_init(void) |
|
{ |
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int ret; |
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struct tty_driver *tty_drv; |
|
|
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sdio_uart_tty_driver = tty_drv = alloc_tty_driver(UART_NR); |
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if (!tty_drv) |
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return -ENOMEM; |
|
|
|
tty_drv->driver_name = "sdio_uart"; |
|
tty_drv->name = "ttySDIO"; |
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tty_drv->major = 0; /* dynamically allocated */ |
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tty_drv->minor_start = 0; |
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tty_drv->type = TTY_DRIVER_TYPE_SERIAL; |
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tty_drv->subtype = SERIAL_TYPE_NORMAL; |
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tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; |
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tty_drv->init_termios = tty_std_termios; |
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tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL; |
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tty_drv->init_termios.c_ispeed = 4800; |
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tty_drv->init_termios.c_ospeed = 4800; |
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tty_set_operations(tty_drv, &sdio_uart_ops); |
|
|
|
ret = tty_register_driver(tty_drv); |
|
if (ret) |
|
goto err1; |
|
|
|
ret = sdio_register_driver(&sdio_uart_driver); |
|
if (ret) |
|
goto err2; |
|
|
|
return 0; |
|
|
|
err2: |
|
tty_unregister_driver(tty_drv); |
|
err1: |
|
put_tty_driver(tty_drv); |
|
return ret; |
|
} |
|
|
|
static void __exit sdio_uart_exit(void) |
|
{ |
|
sdio_unregister_driver(&sdio_uart_driver); |
|
tty_unregister_driver(sdio_uart_tty_driver); |
|
put_tty_driver(sdio_uart_tty_driver); |
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} |
|
|
|
module_init(sdio_uart_init); |
|
module_exit(sdio_uart_exit); |
|
|
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MODULE_AUTHOR("Nicolas Pitre"); |
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MODULE_LICENSE("GPL");
|
|
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