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1006 lines
24 KiB
1006 lines
24 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* st-asc.c: ST Asynchronous serial controller (ASC) driver |
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* |
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* Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited |
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*/ |
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|
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#include <linux/module.h> |
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#include <linux/serial.h> |
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#include <linux/console.h> |
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#include <linux/sysrq.h> |
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#include <linux/pinctrl/consumer.h> |
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#include <linux/platform_device.h> |
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#include <linux/io.h> |
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#include <linux/irq.h> |
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#include <linux/tty.h> |
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#include <linux/tty_flip.h> |
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#include <linux/delay.h> |
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#include <linux/spinlock.h> |
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#include <linux/pm_runtime.h> |
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#include <linux/of.h> |
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#include <linux/of_platform.h> |
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#include <linux/serial_core.h> |
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#include <linux/clk.h> |
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#include <linux/gpio/consumer.h> |
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#define DRIVER_NAME "st-asc" |
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#define ASC_SERIAL_NAME "ttyAS" |
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#define ASC_FIFO_SIZE 16 |
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#define ASC_MAX_PORTS 8 |
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/* Pinctrl states */ |
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#define DEFAULT 0 |
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#define NO_HW_FLOWCTRL 1 |
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struct asc_port { |
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struct uart_port port; |
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struct gpio_desc *rts; |
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struct clk *clk; |
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struct pinctrl *pinctrl; |
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struct pinctrl_state *states[2]; |
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unsigned int hw_flow_control:1; |
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unsigned int force_m1:1; |
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}; |
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static struct asc_port asc_ports[ASC_MAX_PORTS]; |
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static struct uart_driver asc_uart_driver; |
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|
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/*---- UART Register definitions ------------------------------*/ |
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/* Register offsets */ |
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#define ASC_BAUDRATE 0x00 |
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#define ASC_TXBUF 0x04 |
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#define ASC_RXBUF 0x08 |
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#define ASC_CTL 0x0C |
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#define ASC_INTEN 0x10 |
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#define ASC_STA 0x14 |
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#define ASC_GUARDTIME 0x18 |
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#define ASC_TIMEOUT 0x1C |
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#define ASC_TXRESET 0x20 |
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#define ASC_RXRESET 0x24 |
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#define ASC_RETRIES 0x28 |
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/* ASC_RXBUF */ |
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#define ASC_RXBUF_PE 0x100 |
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#define ASC_RXBUF_FE 0x200 |
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/** |
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* Some of status comes from higher bits of the character and some come from |
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* the status register. Combining both of them in to single status using dummy |
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* bits. |
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*/ |
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#define ASC_RXBUF_DUMMY_RX 0x10000 |
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#define ASC_RXBUF_DUMMY_BE 0x20000 |
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#define ASC_RXBUF_DUMMY_OE 0x40000 |
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/* ASC_CTL */ |
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#define ASC_CTL_MODE_MSK 0x0007 |
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#define ASC_CTL_MODE_8BIT 0x0001 |
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#define ASC_CTL_MODE_7BIT_PAR 0x0003 |
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#define ASC_CTL_MODE_9BIT 0x0004 |
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#define ASC_CTL_MODE_8BIT_WKUP 0x0005 |
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#define ASC_CTL_MODE_8BIT_PAR 0x0007 |
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#define ASC_CTL_STOP_MSK 0x0018 |
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#define ASC_CTL_STOP_HALFBIT 0x0000 |
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#define ASC_CTL_STOP_1BIT 0x0008 |
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#define ASC_CTL_STOP_1_HALFBIT 0x0010 |
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#define ASC_CTL_STOP_2BIT 0x0018 |
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#define ASC_CTL_PARITYODD 0x0020 |
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#define ASC_CTL_LOOPBACK 0x0040 |
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#define ASC_CTL_RUN 0x0080 |
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#define ASC_CTL_RXENABLE 0x0100 |
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#define ASC_CTL_SCENABLE 0x0200 |
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#define ASC_CTL_FIFOENABLE 0x0400 |
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#define ASC_CTL_CTSENABLE 0x0800 |
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#define ASC_CTL_BAUDMODE 0x1000 |
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/* ASC_GUARDTIME */ |
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#define ASC_GUARDTIME_MSK 0x00FF |
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/* ASC_INTEN */ |
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#define ASC_INTEN_RBE 0x0001 |
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#define ASC_INTEN_TE 0x0002 |
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#define ASC_INTEN_THE 0x0004 |
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#define ASC_INTEN_PE 0x0008 |
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#define ASC_INTEN_FE 0x0010 |
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#define ASC_INTEN_OE 0x0020 |
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#define ASC_INTEN_TNE 0x0040 |
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#define ASC_INTEN_TOI 0x0080 |
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#define ASC_INTEN_RHF 0x0100 |
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/* ASC_RETRIES */ |
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#define ASC_RETRIES_MSK 0x00FF |
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/* ASC_RXBUF */ |
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#define ASC_RXBUF_MSK 0x03FF |
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/* ASC_STA */ |
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#define ASC_STA_RBF 0x0001 |
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#define ASC_STA_TE 0x0002 |
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#define ASC_STA_THE 0x0004 |
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#define ASC_STA_PE 0x0008 |
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#define ASC_STA_FE 0x0010 |
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#define ASC_STA_OE 0x0020 |
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#define ASC_STA_TNE 0x0040 |
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#define ASC_STA_TOI 0x0080 |
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#define ASC_STA_RHF 0x0100 |
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#define ASC_STA_TF 0x0200 |
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#define ASC_STA_NKD 0x0400 |
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/* ASC_TIMEOUT */ |
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#define ASC_TIMEOUT_MSK 0x00FF |
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/* ASC_TXBUF */ |
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#define ASC_TXBUF_MSK 0x01FF |
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/*---- Inline function definitions ---------------------------*/ |
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static inline struct asc_port *to_asc_port(struct uart_port *port) |
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{ |
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return container_of(port, struct asc_port, port); |
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} |
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static inline u32 asc_in(struct uart_port *port, u32 offset) |
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{ |
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#ifdef readl_relaxed |
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return readl_relaxed(port->membase + offset); |
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#else |
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return readl(port->membase + offset); |
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#endif |
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} |
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static inline void asc_out(struct uart_port *port, u32 offset, u32 value) |
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{ |
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#ifdef writel_relaxed |
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writel_relaxed(value, port->membase + offset); |
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#else |
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writel(value, port->membase + offset); |
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#endif |
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} |
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/* |
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* Some simple utility functions to enable and disable interrupts. |
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* Note that these need to be called with interrupts disabled. |
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*/ |
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static inline void asc_disable_tx_interrupts(struct uart_port *port) |
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{ |
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u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE; |
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asc_out(port, ASC_INTEN, intenable); |
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(void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ |
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} |
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static inline void asc_enable_tx_interrupts(struct uart_port *port) |
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{ |
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u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE; |
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asc_out(port, ASC_INTEN, intenable); |
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} |
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static inline void asc_disable_rx_interrupts(struct uart_port *port) |
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{ |
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u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE; |
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asc_out(port, ASC_INTEN, intenable); |
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(void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ |
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} |
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static inline void asc_enable_rx_interrupts(struct uart_port *port) |
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{ |
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u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE; |
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asc_out(port, ASC_INTEN, intenable); |
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} |
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static inline u32 asc_txfifo_is_empty(struct uart_port *port) |
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{ |
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return asc_in(port, ASC_STA) & ASC_STA_TE; |
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} |
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static inline u32 asc_txfifo_is_half_empty(struct uart_port *port) |
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{ |
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return asc_in(port, ASC_STA) & ASC_STA_THE; |
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} |
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static inline const char *asc_port_name(struct uart_port *port) |
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{ |
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return to_platform_device(port->dev)->name; |
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} |
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/*----------------------------------------------------------------------*/ |
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/* |
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* This section contains code to support the use of the ASC as a |
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* generic serial port. |
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*/ |
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static inline unsigned asc_hw_txroom(struct uart_port *port) |
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{ |
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u32 status = asc_in(port, ASC_STA); |
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if (status & ASC_STA_THE) |
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return port->fifosize / 2; |
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else if (!(status & ASC_STA_TF)) |
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return 1; |
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return 0; |
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} |
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/* |
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* Start transmitting chars. |
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* This is called from both interrupt and task level. |
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* Either way interrupts are disabled. |
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*/ |
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static void asc_transmit_chars(struct uart_port *port) |
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{ |
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struct circ_buf *xmit = &port->state->xmit; |
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int txroom; |
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unsigned char c; |
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txroom = asc_hw_txroom(port); |
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if ((txroom != 0) && port->x_char) { |
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c = port->x_char; |
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port->x_char = 0; |
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asc_out(port, ASC_TXBUF, c); |
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port->icount.tx++; |
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txroom = asc_hw_txroom(port); |
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} |
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if (uart_tx_stopped(port)) { |
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/* |
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* We should try and stop the hardware here, but I |
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* don't think the ASC has any way to do that. |
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*/ |
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asc_disable_tx_interrupts(port); |
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return; |
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} |
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if (uart_circ_empty(xmit)) { |
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asc_disable_tx_interrupts(port); |
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return; |
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} |
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if (txroom == 0) |
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return; |
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do { |
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c = xmit->buf[xmit->tail]; |
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xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); |
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asc_out(port, ASC_TXBUF, c); |
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port->icount.tx++; |
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txroom--; |
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} while ((txroom > 0) && (!uart_circ_empty(xmit))); |
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if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) |
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uart_write_wakeup(port); |
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if (uart_circ_empty(xmit)) |
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asc_disable_tx_interrupts(port); |
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} |
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static void asc_receive_chars(struct uart_port *port) |
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{ |
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struct tty_port *tport = &port->state->port; |
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unsigned long status, mode; |
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unsigned long c = 0; |
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char flag; |
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bool ignore_pe = false; |
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/* |
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* Datasheet states: If the MODE field selects an 8-bit frame then |
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* this [parity error] bit is undefined. Software should ignore this |
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* bit when reading 8-bit frames. |
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*/ |
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mode = asc_in(port, ASC_CTL) & ASC_CTL_MODE_MSK; |
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if (mode == ASC_CTL_MODE_8BIT || mode == ASC_CTL_MODE_8BIT_PAR) |
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ignore_pe = true; |
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if (irqd_is_wakeup_set(irq_get_irq_data(port->irq))) |
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pm_wakeup_event(tport->tty->dev, 0); |
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while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) { |
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c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX; |
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flag = TTY_NORMAL; |
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port->icount.rx++; |
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if (status & ASC_STA_OE || c & ASC_RXBUF_FE || |
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(c & ASC_RXBUF_PE && !ignore_pe)) { |
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if (c & ASC_RXBUF_FE) { |
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if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) { |
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port->icount.brk++; |
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if (uart_handle_break(port)) |
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continue; |
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c |= ASC_RXBUF_DUMMY_BE; |
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} else { |
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port->icount.frame++; |
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} |
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} else if (c & ASC_RXBUF_PE) { |
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port->icount.parity++; |
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} |
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/* |
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* Reading any data from the RX FIFO clears the |
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* overflow error condition. |
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*/ |
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if (status & ASC_STA_OE) { |
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port->icount.overrun++; |
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c |= ASC_RXBUF_DUMMY_OE; |
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} |
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c &= port->read_status_mask; |
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if (c & ASC_RXBUF_DUMMY_BE) |
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flag = TTY_BREAK; |
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else if (c & ASC_RXBUF_PE) |
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flag = TTY_PARITY; |
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else if (c & ASC_RXBUF_FE) |
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flag = TTY_FRAME; |
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} |
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if (uart_handle_sysrq_char(port, c & 0xff)) |
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continue; |
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uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag); |
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} |
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/* Tell the rest of the system the news. New characters! */ |
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tty_flip_buffer_push(tport); |
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} |
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static irqreturn_t asc_interrupt(int irq, void *ptr) |
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{ |
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struct uart_port *port = ptr; |
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u32 status; |
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spin_lock(&port->lock); |
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status = asc_in(port, ASC_STA); |
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if (status & ASC_STA_RBF) { |
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/* Receive FIFO not empty */ |
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asc_receive_chars(port); |
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} |
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if ((status & ASC_STA_THE) && |
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(asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) { |
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/* Transmitter FIFO at least half empty */ |
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asc_transmit_chars(port); |
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} |
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spin_unlock(&port->lock); |
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return IRQ_HANDLED; |
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} |
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/*----------------------------------------------------------------------*/ |
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/* |
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* UART Functions |
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*/ |
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static unsigned int asc_tx_empty(struct uart_port *port) |
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{ |
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return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0; |
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} |
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static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl) |
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{ |
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struct asc_port *ascport = to_asc_port(port); |
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/* |
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* This routine is used for seting signals of: DTR, DCD, CTS and RTS. |
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* We use ASC's hardware for CTS/RTS when hardware flow-control is |
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* enabled, however if the RTS line is required for another purpose, |
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* commonly controlled using HUP from userspace, then we need to toggle |
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* it manually, using GPIO. |
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* |
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* Some boards also have DTR and DCD implemented using PIO pins, code to |
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* do this should be hooked in here. |
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*/ |
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if (!ascport->rts) |
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return; |
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/* If HW flow-control is enabled, we can't fiddle with the RTS line */ |
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if (asc_in(port, ASC_CTL) & ASC_CTL_CTSENABLE) |
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return; |
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gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS); |
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} |
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static unsigned int asc_get_mctrl(struct uart_port *port) |
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{ |
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/* |
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* This routine is used for geting signals of: DTR, DCD, DSR, RI, |
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* and CTS/RTS |
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*/ |
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return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; |
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} |
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/* There are probably characters waiting to be transmitted. */ |
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static void asc_start_tx(struct uart_port *port) |
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{ |
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struct circ_buf *xmit = &port->state->xmit; |
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if (!uart_circ_empty(xmit)) |
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asc_enable_tx_interrupts(port); |
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} |
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/* Transmit stop */ |
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static void asc_stop_tx(struct uart_port *port) |
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{ |
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asc_disable_tx_interrupts(port); |
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} |
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/* Receive stop */ |
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static void asc_stop_rx(struct uart_port *port) |
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{ |
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asc_disable_rx_interrupts(port); |
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} |
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/* Handle breaks - ignored by us */ |
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static void asc_break_ctl(struct uart_port *port, int break_state) |
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{ |
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/* Nothing here yet .. */ |
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} |
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/* |
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* Enable port for reception. |
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*/ |
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static int asc_startup(struct uart_port *port) |
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{ |
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if (request_irq(port->irq, asc_interrupt, 0, |
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asc_port_name(port), port)) { |
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dev_err(port->dev, "cannot allocate irq.\n"); |
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return -ENODEV; |
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} |
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asc_transmit_chars(port); |
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asc_enable_rx_interrupts(port); |
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return 0; |
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} |
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static void asc_shutdown(struct uart_port *port) |
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{ |
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asc_disable_tx_interrupts(port); |
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asc_disable_rx_interrupts(port); |
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free_irq(port->irq, port); |
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} |
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static void asc_pm(struct uart_port *port, unsigned int state, |
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unsigned int oldstate) |
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{ |
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struct asc_port *ascport = to_asc_port(port); |
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unsigned long flags = 0; |
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u32 ctl; |
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switch (state) { |
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case UART_PM_STATE_ON: |
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clk_prepare_enable(ascport->clk); |
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break; |
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case UART_PM_STATE_OFF: |
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/* |
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* Disable the ASC baud rate generator, which is as close as |
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* we can come to turning it off. Note this is not called with |
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* the port spinlock held. |
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*/ |
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spin_lock_irqsave(&port->lock, flags); |
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ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN; |
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asc_out(port, ASC_CTL, ctl); |
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spin_unlock_irqrestore(&port->lock, flags); |
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clk_disable_unprepare(ascport->clk); |
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break; |
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} |
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} |
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static void asc_set_termios(struct uart_port *port, struct ktermios *termios, |
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struct ktermios *old) |
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{ |
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struct asc_port *ascport = to_asc_port(port); |
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struct gpio_desc *gpiod; |
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unsigned int baud; |
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u32 ctrl_val; |
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tcflag_t cflag; |
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unsigned long flags; |
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/* Update termios to reflect hardware capabilities */ |
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termios->c_cflag &= ~(CMSPAR | |
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(ascport->hw_flow_control ? 0 : CRTSCTS)); |
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port->uartclk = clk_get_rate(ascport->clk); |
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baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); |
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cflag = termios->c_cflag; |
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spin_lock_irqsave(&port->lock, flags); |
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/* read control register */ |
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ctrl_val = asc_in(port, ASC_CTL); |
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|
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/* stop serial port and reset value */ |
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asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN)); |
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ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE; |
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|
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/* reset fifo rx & tx */ |
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asc_out(port, ASC_TXRESET, 1); |
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asc_out(port, ASC_RXRESET, 1); |
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/* set character length */ |
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if ((cflag & CSIZE) == CS7) { |
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ctrl_val |= ASC_CTL_MODE_7BIT_PAR; |
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} else { |
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ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR : |
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ASC_CTL_MODE_8BIT; |
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} |
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|
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/* set stop bit */ |
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ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT; |
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/* odd parity */ |
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if (cflag & PARODD) |
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ctrl_val |= ASC_CTL_PARITYODD; |
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/* hardware flow control */ |
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if ((cflag & CRTSCTS)) { |
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ctrl_val |= ASC_CTL_CTSENABLE; |
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/* If flow-control selected, stop handling RTS manually */ |
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if (ascport->rts) { |
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devm_gpiod_put(port->dev, ascport->rts); |
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ascport->rts = NULL; |
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pinctrl_select_state(ascport->pinctrl, |
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ascport->states[DEFAULT]); |
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} |
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} else { |
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/* If flow-control disabled, it's safe to handle RTS manually */ |
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if (!ascport->rts && ascport->states[NO_HW_FLOWCTRL]) { |
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pinctrl_select_state(ascport->pinctrl, |
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ascport->states[NO_HW_FLOWCTRL]); |
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gpiod = devm_gpiod_get(port->dev, "rts", GPIOD_OUT_LOW); |
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if (!IS_ERR(gpiod)) { |
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gpiod_set_consumer_name(gpiod, |
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port->dev->of_node->name); |
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ascport->rts = gpiod; |
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} |
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} |
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} |
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if ((baud < 19200) && !ascport->force_m1) { |
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asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud))); |
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} else { |
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/* |
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* MODE 1: recommended for high bit rates (above 19.2K) |
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* |
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* baudrate * 16 * 2^16 |
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* ASCBaudRate = ------------------------ |
|
* inputclock |
|
* |
|
* To keep maths inside 64bits, we divide inputclock by 16. |
|
*/ |
|
u64 dividend = (u64)baud * (1 << 16); |
|
|
|
do_div(dividend, port->uartclk / 16); |
|
asc_out(port, ASC_BAUDRATE, dividend); |
|
ctrl_val |= ASC_CTL_BAUDMODE; |
|
} |
|
|
|
uart_update_timeout(port, cflag, baud); |
|
|
|
ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE; |
|
if (termios->c_iflag & INPCK) |
|
ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE; |
|
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) |
|
ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE; |
|
|
|
/* |
|
* Characters to ignore |
|
*/ |
|
ascport->port.ignore_status_mask = 0; |
|
if (termios->c_iflag & IGNPAR) |
|
ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE; |
|
if (termios->c_iflag & IGNBRK) { |
|
ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE; |
|
/* |
|
* If we're ignoring parity and break indicators, |
|
* ignore overruns too (for real raw support). |
|
*/ |
|
if (termios->c_iflag & IGNPAR) |
|
ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE; |
|
} |
|
|
|
/* |
|
* Ignore all characters if CREAD is not set. |
|
*/ |
|
if (!(termios->c_cflag & CREAD)) |
|
ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX; |
|
|
|
/* Set the timeout */ |
|
asc_out(port, ASC_TIMEOUT, 20); |
|
|
|
/* write final value and enable port */ |
|
asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN)); |
|
|
|
spin_unlock_irqrestore(&port->lock, flags); |
|
} |
|
|
|
static const char *asc_type(struct uart_port *port) |
|
{ |
|
return (port->type == PORT_ASC) ? DRIVER_NAME : NULL; |
|
} |
|
|
|
static void asc_release_port(struct uart_port *port) |
|
{ |
|
} |
|
|
|
static int asc_request_port(struct uart_port *port) |
|
{ |
|
return 0; |
|
} |
|
|
|
/* |
|
* Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set |
|
* Set type field if successful |
|
*/ |
|
static void asc_config_port(struct uart_port *port, int flags) |
|
{ |
|
if ((flags & UART_CONFIG_TYPE)) |
|
port->type = PORT_ASC; |
|
} |
|
|
|
static int |
|
asc_verify_port(struct uart_port *port, struct serial_struct *ser) |
|
{ |
|
/* No user changeable parameters */ |
|
return -EINVAL; |
|
} |
|
|
|
#ifdef CONFIG_CONSOLE_POLL |
|
/* |
|
* Console polling routines for writing and reading from the uart while |
|
* in an interrupt or debug context (i.e. kgdb). |
|
*/ |
|
|
|
static int asc_get_poll_char(struct uart_port *port) |
|
{ |
|
if (!(asc_in(port, ASC_STA) & ASC_STA_RBF)) |
|
return NO_POLL_CHAR; |
|
|
|
return asc_in(port, ASC_RXBUF); |
|
} |
|
|
|
static void asc_put_poll_char(struct uart_port *port, unsigned char c) |
|
{ |
|
while (!asc_txfifo_is_half_empty(port)) |
|
cpu_relax(); |
|
asc_out(port, ASC_TXBUF, c); |
|
} |
|
|
|
#endif /* CONFIG_CONSOLE_POLL */ |
|
|
|
/*---------------------------------------------------------------------*/ |
|
|
|
static const struct uart_ops asc_uart_ops = { |
|
.tx_empty = asc_tx_empty, |
|
.set_mctrl = asc_set_mctrl, |
|
.get_mctrl = asc_get_mctrl, |
|
.start_tx = asc_start_tx, |
|
.stop_tx = asc_stop_tx, |
|
.stop_rx = asc_stop_rx, |
|
.break_ctl = asc_break_ctl, |
|
.startup = asc_startup, |
|
.shutdown = asc_shutdown, |
|
.set_termios = asc_set_termios, |
|
.type = asc_type, |
|
.release_port = asc_release_port, |
|
.request_port = asc_request_port, |
|
.config_port = asc_config_port, |
|
.verify_port = asc_verify_port, |
|
.pm = asc_pm, |
|
#ifdef CONFIG_CONSOLE_POLL |
|
.poll_get_char = asc_get_poll_char, |
|
.poll_put_char = asc_put_poll_char, |
|
#endif /* CONFIG_CONSOLE_POLL */ |
|
}; |
|
|
|
static int asc_init_port(struct asc_port *ascport, |
|
struct platform_device *pdev) |
|
{ |
|
struct uart_port *port = &ascport->port; |
|
struct resource *res; |
|
int ret; |
|
|
|
port->iotype = UPIO_MEM; |
|
port->flags = UPF_BOOT_AUTOCONF; |
|
port->ops = &asc_uart_ops; |
|
port->fifosize = ASC_FIFO_SIZE; |
|
port->dev = &pdev->dev; |
|
port->irq = platform_get_irq(pdev, 0); |
|
port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_ST_ASC_CONSOLE); |
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
|
port->membase = devm_ioremap_resource(&pdev->dev, res); |
|
if (IS_ERR(port->membase)) |
|
return PTR_ERR(port->membase); |
|
port->mapbase = res->start; |
|
|
|
spin_lock_init(&port->lock); |
|
|
|
ascport->clk = devm_clk_get(&pdev->dev, NULL); |
|
|
|
if (WARN_ON(IS_ERR(ascport->clk))) |
|
return -EINVAL; |
|
/* ensure that clk rate is correct by enabling the clk */ |
|
clk_prepare_enable(ascport->clk); |
|
ascport->port.uartclk = clk_get_rate(ascport->clk); |
|
WARN_ON(ascport->port.uartclk == 0); |
|
clk_disable_unprepare(ascport->clk); |
|
|
|
ascport->pinctrl = devm_pinctrl_get(&pdev->dev); |
|
if (IS_ERR(ascport->pinctrl)) { |
|
ret = PTR_ERR(ascport->pinctrl); |
|
dev_err(&pdev->dev, "Failed to get Pinctrl: %d\n", ret); |
|
return ret; |
|
} |
|
|
|
ascport->states[DEFAULT] = |
|
pinctrl_lookup_state(ascport->pinctrl, "default"); |
|
if (IS_ERR(ascport->states[DEFAULT])) { |
|
ret = PTR_ERR(ascport->states[DEFAULT]); |
|
dev_err(&pdev->dev, |
|
"Failed to look up Pinctrl state 'default': %d\n", ret); |
|
return ret; |
|
} |
|
|
|
/* "no-hw-flowctrl" state is optional */ |
|
ascport->states[NO_HW_FLOWCTRL] = |
|
pinctrl_lookup_state(ascport->pinctrl, "no-hw-flowctrl"); |
|
if (IS_ERR(ascport->states[NO_HW_FLOWCTRL])) |
|
ascport->states[NO_HW_FLOWCTRL] = NULL; |
|
|
|
return 0; |
|
} |
|
|
|
static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev) |
|
{ |
|
struct device_node *np = pdev->dev.of_node; |
|
int id; |
|
|
|
if (!np) |
|
return NULL; |
|
|
|
id = of_alias_get_id(np, "serial"); |
|
if (id < 0) |
|
id = of_alias_get_id(np, ASC_SERIAL_NAME); |
|
|
|
if (id < 0) |
|
id = 0; |
|
|
|
if (WARN_ON(id >= ASC_MAX_PORTS)) |
|
return NULL; |
|
|
|
asc_ports[id].hw_flow_control = of_property_read_bool(np, |
|
"uart-has-rtscts"); |
|
asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1"); |
|
asc_ports[id].port.line = id; |
|
asc_ports[id].rts = NULL; |
|
|
|
return &asc_ports[id]; |
|
} |
|
|
|
#ifdef CONFIG_OF |
|
static const struct of_device_id asc_match[] = { |
|
{ .compatible = "st,asc", }, |
|
{}, |
|
}; |
|
|
|
MODULE_DEVICE_TABLE(of, asc_match); |
|
#endif |
|
|
|
static int asc_serial_probe(struct platform_device *pdev) |
|
{ |
|
int ret; |
|
struct asc_port *ascport; |
|
|
|
ascport = asc_of_get_asc_port(pdev); |
|
if (!ascport) |
|
return -ENODEV; |
|
|
|
ret = asc_init_port(ascport, pdev); |
|
if (ret) |
|
return ret; |
|
|
|
ret = uart_add_one_port(&asc_uart_driver, &ascport->port); |
|
if (ret) |
|
return ret; |
|
|
|
platform_set_drvdata(pdev, &ascport->port); |
|
|
|
return 0; |
|
} |
|
|
|
static int asc_serial_remove(struct platform_device *pdev) |
|
{ |
|
struct uart_port *port = platform_get_drvdata(pdev); |
|
|
|
return uart_remove_one_port(&asc_uart_driver, port); |
|
} |
|
|
|
#ifdef CONFIG_PM_SLEEP |
|
static int asc_serial_suspend(struct device *dev) |
|
{ |
|
struct uart_port *port = dev_get_drvdata(dev); |
|
|
|
return uart_suspend_port(&asc_uart_driver, port); |
|
} |
|
|
|
static int asc_serial_resume(struct device *dev) |
|
{ |
|
struct uart_port *port = dev_get_drvdata(dev); |
|
|
|
return uart_resume_port(&asc_uart_driver, port); |
|
} |
|
|
|
#endif /* CONFIG_PM_SLEEP */ |
|
|
|
/*----------------------------------------------------------------------*/ |
|
|
|
#ifdef CONFIG_SERIAL_ST_ASC_CONSOLE |
|
static void asc_console_putchar(struct uart_port *port, int ch) |
|
{ |
|
unsigned int timeout = 1000000; |
|
|
|
/* Wait for upto 1 second in case flow control is stopping us. */ |
|
while (--timeout && !asc_txfifo_is_half_empty(port)) |
|
udelay(1); |
|
|
|
asc_out(port, ASC_TXBUF, ch); |
|
} |
|
|
|
/* |
|
* Print a string to the serial port trying not to disturb |
|
* any possible real use of the port... |
|
*/ |
|
|
|
static void asc_console_write(struct console *co, const char *s, unsigned count) |
|
{ |
|
struct uart_port *port = &asc_ports[co->index].port; |
|
unsigned long flags; |
|
unsigned long timeout = 1000000; |
|
int locked = 1; |
|
u32 intenable; |
|
|
|
if (port->sysrq) |
|
locked = 0; /* asc_interrupt has already claimed the lock */ |
|
else if (oops_in_progress) |
|
locked = spin_trylock_irqsave(&port->lock, flags); |
|
else |
|
spin_lock_irqsave(&port->lock, flags); |
|
|
|
/* |
|
* Disable interrupts so we don't get the IRQ line bouncing |
|
* up and down while interrupts are disabled. |
|
*/ |
|
intenable = asc_in(port, ASC_INTEN); |
|
asc_out(port, ASC_INTEN, 0); |
|
(void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ |
|
|
|
uart_console_write(port, s, count, asc_console_putchar); |
|
|
|
while (--timeout && !asc_txfifo_is_empty(port)) |
|
udelay(1); |
|
|
|
asc_out(port, ASC_INTEN, intenable); |
|
|
|
if (locked) |
|
spin_unlock_irqrestore(&port->lock, flags); |
|
} |
|
|
|
static int asc_console_setup(struct console *co, char *options) |
|
{ |
|
struct asc_port *ascport; |
|
int baud = 115200; |
|
int bits = 8; |
|
int parity = 'n'; |
|
int flow = 'n'; |
|
|
|
if (co->index >= ASC_MAX_PORTS) |
|
return -ENODEV; |
|
|
|
ascport = &asc_ports[co->index]; |
|
|
|
/* |
|
* This driver does not support early console initialization |
|
* (use ARM early printk support instead), so we only expect |
|
* this to be called during the uart port registration when the |
|
* driver gets probed and the port should be mapped at that point. |
|
*/ |
|
if (ascport->port.mapbase == 0 || ascport->port.membase == NULL) |
|
return -ENXIO; |
|
|
|
if (options) |
|
uart_parse_options(options, &baud, &parity, &bits, &flow); |
|
|
|
return uart_set_options(&ascport->port, co, baud, parity, bits, flow); |
|
} |
|
|
|
static struct console asc_console = { |
|
.name = ASC_SERIAL_NAME, |
|
.device = uart_console_device, |
|
.write = asc_console_write, |
|
.setup = asc_console_setup, |
|
.flags = CON_PRINTBUFFER, |
|
.index = -1, |
|
.data = &asc_uart_driver, |
|
}; |
|
|
|
#define ASC_SERIAL_CONSOLE (&asc_console) |
|
|
|
#else |
|
#define ASC_SERIAL_CONSOLE NULL |
|
#endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */ |
|
|
|
static struct uart_driver asc_uart_driver = { |
|
.owner = THIS_MODULE, |
|
.driver_name = DRIVER_NAME, |
|
.dev_name = ASC_SERIAL_NAME, |
|
.major = 0, |
|
.minor = 0, |
|
.nr = ASC_MAX_PORTS, |
|
.cons = ASC_SERIAL_CONSOLE, |
|
}; |
|
|
|
static const struct dev_pm_ops asc_serial_pm_ops = { |
|
SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume) |
|
}; |
|
|
|
static struct platform_driver asc_serial_driver = { |
|
.probe = asc_serial_probe, |
|
.remove = asc_serial_remove, |
|
.driver = { |
|
.name = DRIVER_NAME, |
|
.pm = &asc_serial_pm_ops, |
|
.of_match_table = of_match_ptr(asc_match), |
|
}, |
|
}; |
|
|
|
static int __init asc_init(void) |
|
{ |
|
int ret; |
|
static const char banner[] __initconst = |
|
KERN_INFO "STMicroelectronics ASC driver initialized\n"; |
|
|
|
printk(banner); |
|
|
|
ret = uart_register_driver(&asc_uart_driver); |
|
if (ret) |
|
return ret; |
|
|
|
ret = platform_driver_register(&asc_serial_driver); |
|
if (ret) |
|
uart_unregister_driver(&asc_uart_driver); |
|
|
|
return ret; |
|
} |
|
|
|
static void __exit asc_exit(void) |
|
{ |
|
platform_driver_unregister(&asc_serial_driver); |
|
uart_unregister_driver(&asc_uart_driver); |
|
} |
|
|
|
module_init(asc_init); |
|
module_exit(asc_exit); |
|
|
|
MODULE_ALIAS("platform:" DRIVER_NAME); |
|
MODULE_AUTHOR("STMicroelectronics (R&D) Limited"); |
|
MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver"); |
|
MODULE_LICENSE("GPL");
|
|
|