linux/drivers/tty/serial/clps711x.c

525 lines
13 KiB
C

/*
* Driver for CLPS711x serial ports
*
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
* Copyright 1999 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#if defined(CONFIG_SERIAL_CLPS711X_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/module.h>
#include <linux/device.h>
#include <linux/console.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <mach/hardware.h>
#define UART_CLPS711X_NAME "uart-clps711x"
#define UART_CLPS711X_NR 2
#define UART_CLPS711X_MAJOR 204
#define UART_CLPS711X_MINOR 40
#define UBRLCR(port) ((port)->line ? UBRLCR2 : UBRLCR1)
#define UARTDR(port) ((port)->line ? UARTDR2 : UARTDR1)
#define SYSFLG(port) ((port)->line ? SYSFLG2 : SYSFLG1)
#define SYSCON(port) ((port)->line ? SYSCON2 : SYSCON1)
#define TX_IRQ(port) ((port)->line ? IRQ_UTXINT2 : IRQ_UTXINT1)
#define RX_IRQ(port) ((port)->line ? IRQ_URXINT2 : IRQ_URXINT1)
struct clps711x_port {
struct uart_driver uart;
struct clk *uart_clk;
struct uart_port port[UART_CLPS711X_NR];
int tx_enabled[UART_CLPS711X_NR];
#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
struct console console;
#endif
};
static void uart_clps711x_stop_tx(struct uart_port *port)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
if (s->tx_enabled[port->line]) {
disable_irq(TX_IRQ(port));
s->tx_enabled[port->line] = 0;
}
}
static void uart_clps711x_start_tx(struct uart_port *port)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
if (!s->tx_enabled[port->line]) {
enable_irq(TX_IRQ(port));
s->tx_enabled[port->line] = 1;
}
}
static void uart_clps711x_stop_rx(struct uart_port *port)
{
disable_irq(RX_IRQ(port));
}
static void uart_clps711x_enable_ms(struct uart_port *port)
{
/* Do nothing */
}
static irqreturn_t uart_clps711x_int_rx(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
unsigned int status, ch, flg;
for (;;) {
status = clps_readl(SYSFLG(port));
if (status & SYSFLG_URXFE)
break;
ch = clps_readw(UARTDR(port));
status = ch & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR);
ch &= 0xff;
port->icount.rx++;
flg = TTY_NORMAL;
if (unlikely(status)) {
if (status & UARTDR_PARERR)
port->icount.parity++;
else if (status & UARTDR_FRMERR)
port->icount.frame++;
else if (status & UARTDR_OVERR)
port->icount.overrun++;
status &= port->read_status_mask;
if (status & UARTDR_PARERR)
flg = TTY_PARITY;
else if (status & UARTDR_FRMERR)
flg = TTY_FRAME;
else if (status & UARTDR_OVERR)
flg = TTY_OVERRUN;
}
if (uart_handle_sysrq_char(port, ch))
continue;
if (status & port->ignore_status_mask)
continue;
uart_insert_char(port, status, UARTDR_OVERR, ch, flg);
}
tty_flip_buffer_push(&port->state->port);
return IRQ_HANDLED;
}
static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct clps711x_port *s = dev_get_drvdata(port->dev);
struct circ_buf *xmit = &port->state->xmit;
if (port->x_char) {
clps_writew(port->x_char, UARTDR(port));
port->icount.tx++;
port->x_char = 0;
return IRQ_HANDLED;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
disable_irq_nosync(TX_IRQ(port));
s->tx_enabled[port->line] = 0;
return IRQ_HANDLED;
}
while (!uart_circ_empty(xmit)) {
clps_writew(xmit->buf[xmit->tail], UARTDR(port));
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (clps_readl(SYSFLG(port) & SYSFLG_UTXFF))
break;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
return IRQ_HANDLED;
}
static unsigned int uart_clps711x_tx_empty(struct uart_port *port)
{
return (clps_readl(SYSFLG(port) & SYSFLG_UBUSY)) ? 0 : TIOCSER_TEMT;
}
static unsigned int uart_clps711x_get_mctrl(struct uart_port *port)
{
unsigned int status, result = 0;
if (port->line == 0) {
status = clps_readl(SYSFLG1);
if (status & SYSFLG1_DCD)
result |= TIOCM_CAR;
if (status & SYSFLG1_DSR)
result |= TIOCM_DSR;
if (status & SYSFLG1_CTS)
result |= TIOCM_CTS;
} else
result = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
return result;
}
static void uart_clps711x_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
/* Do nothing */
}
static void uart_clps711x_break_ctl(struct uart_port *port, int break_state)
{
unsigned long flags;
unsigned int ubrlcr;
spin_lock_irqsave(&port->lock, flags);
ubrlcr = clps_readl(UBRLCR(port));
if (break_state)
ubrlcr |= UBRLCR_BREAK;
else
ubrlcr &= ~UBRLCR_BREAK;
clps_writel(ubrlcr, UBRLCR(port));
spin_unlock_irqrestore(&port->lock, flags);
}
static int uart_clps711x_startup(struct uart_port *port)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
int ret;
s->tx_enabled[port->line] = 1;
/* Allocate the IRQs */
ret = devm_request_irq(port->dev, TX_IRQ(port), uart_clps711x_int_tx,
0, UART_CLPS711X_NAME " TX", port);
if (ret)
return ret;
ret = devm_request_irq(port->dev, RX_IRQ(port), uart_clps711x_int_rx,
0, UART_CLPS711X_NAME " RX", port);
if (ret) {
devm_free_irq(port->dev, TX_IRQ(port), port);
return ret;
}
/* Disable break */
clps_writel(clps_readl(UBRLCR(port)) & ~UBRLCR_BREAK, UBRLCR(port));
/* Enable the port */
clps_writel(clps_readl(SYSCON(port)) | SYSCON_UARTEN, SYSCON(port));
return 0;
}
static void uart_clps711x_shutdown(struct uart_port *port)
{
/* Free the interrupts */
devm_free_irq(port->dev, TX_IRQ(port), port);
devm_free_irq(port->dev, RX_IRQ(port), port);
/* Disable the port */
clps_writel(clps_readl(SYSCON(port)) & ~SYSCON_UARTEN, SYSCON(port));
}
static void uart_clps711x_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
unsigned int ubrlcr, baud, quot;
unsigned long flags;
/* Mask termios capabilities we don't support */
termios->c_cflag &= ~CMSPAR;
termios->c_iflag &= ~(BRKINT | IGNBRK);
/* Ask the core to calculate the divisor for us */
baud = uart_get_baud_rate(port, termios, old, port->uartclk / 4096,
port->uartclk / 16);
quot = uart_get_divisor(port, baud);
switch (termios->c_cflag & CSIZE) {
case CS5:
ubrlcr = UBRLCR_WRDLEN5;
break;
case CS6:
ubrlcr = UBRLCR_WRDLEN6;
break;
case CS7:
ubrlcr = UBRLCR_WRDLEN7;
break;
case CS8:
default:
ubrlcr = UBRLCR_WRDLEN8;
break;
}
if (termios->c_cflag & CSTOPB)
ubrlcr |= UBRLCR_XSTOP;
if (termios->c_cflag & PARENB) {
ubrlcr |= UBRLCR_PRTEN;
if (!(termios->c_cflag & PARODD))
ubrlcr |= UBRLCR_EVENPRT;
}
/* Enable FIFO */
ubrlcr |= UBRLCR_FIFOEN;
spin_lock_irqsave(&port->lock, flags);
/* Set read status mask */
port->read_status_mask = UARTDR_OVERR;
if (termios->c_iflag & INPCK)
port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
/* Set status ignore mask */
port->ignore_status_mask = 0;
if (!(termios->c_cflag & CREAD))
port->ignore_status_mask |= UARTDR_OVERR | UARTDR_PARERR |
UARTDR_FRMERR;
uart_update_timeout(port, termios->c_cflag, baud);
clps_writel(ubrlcr | (quot - 1), UBRLCR(port));
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *uart_clps711x_type(struct uart_port *port)
{
return (port->type == PORT_CLPS711X) ? "CLPS711X" : NULL;
}
static void uart_clps711x_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE)
port->type = PORT_CLPS711X;
}
static void uart_clps711x_release_port(struct uart_port *port)
{
/* Do nothing */
}
static int uart_clps711x_request_port(struct uart_port *port)
{
/* Do nothing */
return 0;
}
static const struct uart_ops uart_clps711x_ops = {
.tx_empty = uart_clps711x_tx_empty,
.set_mctrl = uart_clps711x_set_mctrl,
.get_mctrl = uart_clps711x_get_mctrl,
.stop_tx = uart_clps711x_stop_tx,
.start_tx = uart_clps711x_start_tx,
.stop_rx = uart_clps711x_stop_rx,
.enable_ms = uart_clps711x_enable_ms,
.break_ctl = uart_clps711x_break_ctl,
.startup = uart_clps711x_startup,
.shutdown = uart_clps711x_shutdown,
.set_termios = uart_clps711x_set_termios,
.type = uart_clps711x_type,
.config_port = uart_clps711x_config_port,
.release_port = uart_clps711x_release_port,
.request_port = uart_clps711x_request_port,
};
#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
static void uart_clps711x_console_putchar(struct uart_port *port, int ch)
{
while (clps_readl(SYSFLG(port)) & SYSFLG_UTXFF)
barrier();
clps_writew(ch, UARTDR(port));
}
static void uart_clps711x_console_write(struct console *co, const char *c,
unsigned n)
{
struct clps711x_port *s = (struct clps711x_port *)co->data;
struct uart_port *port = &s->port[co->index];
u32 syscon;
/* Ensure that the port is enabled */
syscon = clps_readl(SYSCON(port));
clps_writel(syscon | SYSCON_UARTEN, SYSCON(port));
uart_console_write(port, c, n, uart_clps711x_console_putchar);
/* Wait for transmitter to become empty */
while (clps_readl(SYSFLG(port)) & SYSFLG_UBUSY)
barrier();
/* Restore the uart state */
clps_writel(syscon, SYSCON(port));
}
static void uart_clps711x_console_get_options(struct uart_port *port,
int *baud, int *parity,
int *bits)
{
if (clps_readl(SYSCON(port)) & SYSCON_UARTEN) {
unsigned int ubrlcr, quot;
ubrlcr = clps_readl(UBRLCR(port));
*parity = 'n';
if (ubrlcr & UBRLCR_PRTEN) {
if (ubrlcr & UBRLCR_EVENPRT)
*parity = 'e';
else
*parity = 'o';
}
if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7)
*bits = 7;
else
*bits = 8;
quot = ubrlcr & UBRLCR_BAUD_MASK;
*baud = port->uartclk / (16 * (quot + 1));
}
}
static int uart_clps711x_console_setup(struct console *co, char *options)
{
int baud = 38400, bits = 8, parity = 'n', flow = 'n';
struct clps711x_port *s = (struct clps711x_port *)co->data;
struct uart_port *port = &s->port[(co->index > 0) ? co->index : 0];
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
uart_clps711x_console_get_options(port, &baud, &parity, &bits);
return uart_set_options(port, co, baud, parity, bits, flow);
}
#endif
static int uart_clps711x_probe(struct platform_device *pdev)
{
struct clps711x_port *s;
int ret, i;
s = devm_kzalloc(&pdev->dev, sizeof(struct clps711x_port), GFP_KERNEL);
if (!s) {
dev_err(&pdev->dev, "Error allocating port structure\n");
return -ENOMEM;
}
platform_set_drvdata(pdev, s);
s->uart_clk = devm_clk_get(&pdev->dev, "uart");
if (IS_ERR(s->uart_clk)) {
dev_err(&pdev->dev, "Can't get UART clocks\n");
return PTR_ERR(s->uart_clk);
}
s->uart.owner = THIS_MODULE;
s->uart.dev_name = "ttyCL";
s->uart.major = UART_CLPS711X_MAJOR;
s->uart.minor = UART_CLPS711X_MINOR;
s->uart.nr = UART_CLPS711X_NR;
#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
s->uart.cons = &s->console;
s->uart.cons->device = uart_console_device;
s->uart.cons->write = uart_clps711x_console_write;
s->uart.cons->setup = uart_clps711x_console_setup;
s->uart.cons->flags = CON_PRINTBUFFER;
s->uart.cons->index = -1;
s->uart.cons->data = s;
strcpy(s->uart.cons->name, "ttyCL");
#endif
ret = uart_register_driver(&s->uart);
if (ret) {
dev_err(&pdev->dev, "Registering UART driver failed\n");
devm_clk_put(&pdev->dev, s->uart_clk);
return ret;
}
for (i = 0; i < UART_CLPS711X_NR; i++) {
s->port[i].line = i;
s->port[i].dev = &pdev->dev;
s->port[i].irq = TX_IRQ(&s->port[i]);
s->port[i].iobase = SYSCON(&s->port[i]);
s->port[i].type = PORT_CLPS711X;
s->port[i].fifosize = 16;
s->port[i].flags = UPF_SKIP_TEST | UPF_FIXED_TYPE;
s->port[i].uartclk = clk_get_rate(s->uart_clk);
s->port[i].ops = &uart_clps711x_ops;
WARN_ON(uart_add_one_port(&s->uart, &s->port[i]));
}
return 0;
}
static int uart_clps711x_remove(struct platform_device *pdev)
{
struct clps711x_port *s = platform_get_drvdata(pdev);
int i;
for (i = 0; i < UART_CLPS711X_NR; i++)
uart_remove_one_port(&s->uart, &s->port[i]);
devm_clk_put(&pdev->dev, s->uart_clk);
uart_unregister_driver(&s->uart);
return 0;
}
static struct platform_driver clps711x_uart_driver = {
.driver = {
.name = UART_CLPS711X_NAME,
.owner = THIS_MODULE,
},
.probe = uart_clps711x_probe,
.remove = uart_clps711x_remove,
};
module_platform_driver(clps711x_uart_driver);
static struct platform_device clps711x_uart_device = {
.name = UART_CLPS711X_NAME,
};
static int __init uart_clps711x_init(void)
{
return platform_device_register(&clps711x_uart_device);
}
module_init(uart_clps711x_init);
static void __exit uart_clps711x_exit(void)
{
platform_device_unregister(&clps711x_uart_device);
}
module_exit(uart_clps711x_exit);
MODULE_AUTHOR("Deep Blue Solutions Ltd");
MODULE_DESCRIPTION("CLPS711X serial driver");
MODULE_LICENSE("GPL");