openwrt/target/linux/adm5120/files/drivers/serial/adm5120_uart.c

521 lines
13 KiB
C

/*
* Serial driver for ADM5120 SoC
*
* Derived from drivers/serial/uart00.c
* Copyright 2001 Altera Corporation
*
* Some pieces are derived from the ADMtek 2.4 serial driver.
* Copyright (C) ADMtek Incorporated, 2003
* daniell@admtek.com.tw
* Which again was derived from drivers/char/serial.c
* Copyright (C) Linus Torvalds et al.
*
* Copyright Jeroen Vreeken (pe1rxq@amsat.org), 2005
*/
#include <linux/autoconf.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/console.h>
#include <asm/mach-adm5120/adm5120_defs.h>
#include <asm/mach-adm5120/adm5120_irq.h>
#define ADM5120_UART_REG(base, reg) \
(*(volatile u32 *)KSEG1ADDR((base)+(reg)))
#define ADM5120_UARTCLK_FREQ 62500000
#define ADM5120_UART_BAUDDIV(rate) ((unsigned long)(ADM5120_UARTCLK_FREQ/(16*(rate)) - 1))
#define ADM5120_UART_BAUD115200 ADM5120_UART_BAUDDIV(115200)
#define ADM5120_UART_DATA 0x00
#define ADM5120_UART_RS 0x04
#define ADM5120_UART_LCR_H 0x08
#define ADM5120_UART_LCR_M 0x0c
#define ADM5120_UART_LCR_L 0x10
#define ADM5120_UART_CR 0x14
#define ADM5120_UART_FR 0x18
#define ADM5120_UART_IR 0x1c
#define ADM5120_UART_FE 0x01
#define ADM5120_UART_PE 0x02
#define ADM5120_UART_BE 0x04
#define ADM5120_UART_OE 0x08
#define ADM5120_UART_ERR 0x0f
#define ADM5120_UART_FIFO_EN 0x10
#define ADM5120_UART_EN 0x01
#define ADM5120_UART_TIE 0x20
#define ADM5120_UART_RIE 0x50
#define ADM5120_UART_IE 0x78
#define ADM5120_UART_CTS 0x01
#define ADM5120_UART_DSR 0x02
#define ADM5120_UART_DCD 0x04
#define ADM5120_UART_TXFF 0x20
#define ADM5120_UART_TXFE 0x80
#define ADM5120_UART_RXFE 0x10
#define ADM5120_UART_BRK 0x01
#define ADM5120_UART_PEN 0x02
#define ADM5120_UART_EPS 0x04
#define ADM5120_UART_STP2 0x08
#define ADM5120_UART_W5 0x00
#define ADM5120_UART_W6 0x20
#define ADM5120_UART_W7 0x40
#define ADM5120_UART_W8 0x60
#define ADM5120_UART_MIS 0x01
#define ADM5120_UART_RIS 0x02
#define ADM5120_UART_TIS 0x04
#define ADM5120_UART_RTIS 0x08
static void adm5120ser_stop_tx(struct uart_port *port)
{
ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_TIE;
}
static void adm5120ser_irq_rx(struct uart_port *port)
{
struct tty_struct *tty = port->info->tty;
unsigned int status, ch, rds, flg, ignored = 0;
status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
while (!(status & ADM5120_UART_RXFE)) {
/*
* We need to read rds before reading the
* character from the fifo
*/
rds = ADM5120_UART_REG(port->iobase, ADM5120_UART_RS);
ch = ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA);
port->icount.rx++;
if (tty->low_latency)
tty_flip_buffer_push(tty);
flg = TTY_NORMAL;
/*
* Note that the error handling code is
* out of the main execution path
*/
if (rds & ADM5120_UART_ERR)
goto handle_error;
if (uart_handle_sysrq_char(port, ch))
goto ignore_char;
error_return:
tty_insert_flip_char(tty, ch, flg);
ignore_char:
status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
}
out:
tty_flip_buffer_push(tty);
return;
handle_error:
ADM5120_UART_REG(port->iobase, ADM5120_UART_RS) = 0xff;
if (rds & ADM5120_UART_BE) {
port->icount.brk++;
if (uart_handle_break(port))
goto ignore_char;
} else if (rds & ADM5120_UART_PE)
port->icount.parity++;
else if (rds & ADM5120_UART_FE)
port->icount.frame++;
if (rds & ADM5120_UART_OE)
port->icount.overrun++;
if (rds & port->ignore_status_mask) {
if (++ignored > 100)
goto out;
goto ignore_char;
}
rds &= port->read_status_mask;
if (rds & ADM5120_UART_BE)
flg = TTY_BREAK;
else if (rds & ADM5120_UART_PE)
flg = TTY_PARITY;
else if (rds & ADM5120_UART_FE)
flg = TTY_FRAME;
if (rds & ADM5120_UART_OE) {
/*
* CHECK: does overrun affect the current character?
* ASSUMPTION: it does not.
*/
tty_insert_flip_char(tty, ch, flg);
ch = 0;
flg = TTY_OVERRUN;
}
#ifdef CONFIG_MAGIC_SYSRQ
port->sysrq = 0;
#endif
goto error_return;
}
static void adm5120ser_irq_tx(struct uart_port *port)
{
struct circ_buf *xmit = &port->info->xmit;
int count;
if (port->x_char) {
ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA) =
port->x_char;
port->icount.tx++;
port->x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
adm5120ser_stop_tx(port);
return;
}
count = port->fifosize >> 1;
do {
ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA) =
xmit->buf[xmit->tail];
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_empty(xmit))
break;
} while (--count > 0);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (uart_circ_empty(xmit))
adm5120ser_stop_tx(port);
}
static void adm5120ser_irq_modem(struct uart_port *port)
{
unsigned int status;
status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
if (status & ADM5120_UART_DCD)
uart_handle_dcd_change(port, status & ADM5120_UART_DCD);
if (status & ADM5120_UART_DSR)
port->icount.dsr++;
if (status & ADM5120_UART_CTS)
uart_handle_cts_change(port, status & ADM5120_UART_CTS);
wake_up_interruptible(&port->info->delta_msr_wait);
}
static irqreturn_t adm5120ser_irq(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
unsigned long ir = ADM5120_UART_REG(port->iobase, ADM5120_UART_IR);
if (ir & (ADM5120_UART_RIS | ADM5120_UART_RTIS))
adm5120ser_irq_rx(port);
if (ir & ADM5120_UART_TIS)
adm5120ser_irq_tx(port);
if (ir & ADM5120_UART_MIS) {
adm5120ser_irq_modem(port);
ADM5120_UART_REG(port->iobase, ADM5120_UART_IR) = 0xff;
}
return IRQ_HANDLED;
}
static unsigned int adm5120ser_tx_empty(struct uart_port *port)
{
unsigned int fr = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
return (fr & ADM5120_UART_TXFE) ? TIOCSER_TEMT : 0;
}
static void adm5120ser_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}
static unsigned int adm5120ser_get_mctrl(struct uart_port *port)
{
unsigned int result = 0;
unsigned int fr = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
if (fr & ADM5120_UART_CTS)
result |= TIOCM_CTS;
if (fr & ADM5120_UART_DSR)
result |= TIOCM_DSR;
if (fr & ADM5120_UART_DCD)
result |= TIOCM_CAR;
return result;
}
static void adm5120ser_start_tx(struct uart_port *port)
{
ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) |= ADM5120_UART_TIE;
}
static void adm5120ser_stop_rx(struct uart_port *port)
{
ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_RIE;
}
static void adm5120ser_enable_ms(struct uart_port *port)
{
}
static void adm5120ser_break_ctl(struct uart_port *port, int break_state)
{
unsigned long flags;
unsigned long lcrh;
spin_lock_irqsave(&port->lock, flags);
lcrh = ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H);
if (break_state == -1)
lcrh |= ADM5120_UART_BRK;
else
lcrh &= ~ADM5120_UART_BRK;
ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) = lcrh;
spin_unlock_irqrestore(&port->lock, flags);
}
static int adm5120ser_startup(struct uart_port *port)
{
int ret;
ret = request_irq(port->irq, adm5120ser_irq, 0, "ADM5120 UART", port);
if (ret) {
printk(KERN_ERR "Couldn't get irq %d\n", port->irq);
return ret;
}
ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) |=
ADM5120_UART_FIFO_EN;
ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) |=
ADM5120_UART_EN | ADM5120_UART_IE;
return 0;
}
static void adm5120ser_shutdown(struct uart_port *port)
{
ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_IE;
free_irq(port->irq, port);
}
static void adm5120ser_set_termios(struct uart_port *port,
struct ktermios *termios, struct ktermios *old)
{
unsigned int baud, quot, lcrh;
unsigned long flags;
termios->c_cflag |= CREAD;
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
quot = uart_get_divisor(port, baud);
lcrh = ADM5120_UART_FIFO_EN;
switch (termios->c_cflag & CSIZE) {
case CS5:
lcrh |= ADM5120_UART_W5;
break;
case CS6:
lcrh |= ADM5120_UART_W6;
break;
case CS7:
lcrh |= ADM5120_UART_W7;
break;
default:
lcrh |= ADM5120_UART_W8;
break;
}
if (termios->c_cflag & CSTOPB)
lcrh |= ADM5120_UART_STP2;
if (termios->c_cflag & PARENB) {
lcrh |= ADM5120_UART_PEN;
if (!(termios->c_cflag & PARODD))
lcrh |= ADM5120_UART_EPS;
}
spin_lock_irqsave(port->lock, flags);
ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) = lcrh;
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
port->read_status_mask = ADM5120_UART_OE;
if (termios->c_iflag & INPCK)
port->read_status_mask |= ADM5120_UART_FE | ADM5120_UART_PE;
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= ADM5120_UART_BE;
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= ADM5120_UART_FE | ADM5120_UART_PE;
if (termios->c_iflag & IGNBRK) {
port->ignore_status_mask |= ADM5120_UART_BE;
/*
* If we're ignoring parity and break indicators,
* ignore overruns to (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= ADM5120_UART_OE;
}
quot = ADM5120_UART_BAUD115200;
ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_L) = quot & 0xff;
ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_M) = quot >> 8;
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *adm5120ser_type(struct uart_port *port)
{
return port->type == PORT_ADM5120 ? "ADM5120" : NULL;
}
static void adm5120ser_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE)
port->type = PORT_ADM5120;
}
static void adm5120ser_release_port(struct uart_port *port)
{
release_mem_region(port->iobase, ADM5120_UART_SIZE);
}
static int adm5120ser_request_port(struct uart_port *port)
{
return request_mem_region(port->iobase, ADM5120_UART_SIZE,
"adm5120-uart") != NULL ? 0 : -EBUSY;
}
static struct uart_ops adm5120ser_ops = {
.tx_empty = adm5120ser_tx_empty,
.set_mctrl = adm5120ser_set_mctrl,
.get_mctrl = adm5120ser_get_mctrl,
.stop_tx = adm5120ser_stop_tx,
.start_tx = adm5120ser_start_tx,
.stop_rx = adm5120ser_stop_rx,
.enable_ms = adm5120ser_enable_ms,
.break_ctl = adm5120ser_break_ctl,
.startup = adm5120ser_startup,
.shutdown = adm5120ser_shutdown,
.set_termios = adm5120ser_set_termios,
.type = adm5120ser_type,
.config_port = adm5120ser_config_port,
.release_port = adm5120ser_release_port,
.request_port = adm5120ser_request_port,
};
static void adm5120console_put(const char c)
{
while ((ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_FR) &
ADM5120_UART_TXFF) != 0);
ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_DATA) = c;
}
static void adm5120console_write(struct console *con, const char *s,
unsigned int count)
{
while (count--) {
if (*s == '\n')
adm5120console_put('\r');
adm5120console_put(*s);
s++;
}
}
static int adm5120console_setup(struct console *con, char *options)
{
/* Set to 115200 baud, 8N1 and enable FIFO */
ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_LCR_L) =
ADM5120_UART_BAUD115200 & 0xff;
ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_LCR_M) =
ADM5120_UART_BAUD115200 >> 8;
ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_LCR_H) =
ADM5120_UART_W8 | ADM5120_UART_FIFO_EN;
/* Enable port */
ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_CR) =
ADM5120_UART_EN;
return 0;
}
static struct uart_driver adm5120ser_reg;
static struct console adm5120_serconsole = {
.name = "ttyS",
.write = adm5120console_write,
.device = uart_console_device,
.setup = adm5120console_setup,
.flags = CON_PRINTBUFFER,
.cflag = B115200 | CS8 | CREAD,
.index = 0,
.data = &adm5120ser_reg,
};
static int __init adm5120console_init(void)
{
register_console(&adm5120_serconsole);
return 0;
}
console_initcall(adm5120console_init);
static struct uart_port adm5120ser_ports[] = {
{
.iobase = ADM5120_UART0_BASE,
.irq = ADM5120_IRQ_UART0,
.uartclk = ADM5120_UARTCLK_FREQ,
.fifosize = 16,
.ops = &adm5120ser_ops,
.line = 0,
.flags = ASYNC_BOOT_AUTOCONF,
},
#if (CONFIG_ADM5120_NR_UARTS > 1)
{
.iobase = ADM5120_UART1_BASE,
.irq = ADM5120_IRQ_UART1,
.uartclk = ADM5120_UARTCLK_FREQ,
.fifosize = 16,
.ops = &adm5120ser_ops,
.line = 1,
.flags = ASYNC_BOOT_AUTOCONF,
},
#endif
};
static struct uart_driver adm5120ser_reg = {
.owner = THIS_MODULE,
.driver_name = "ttyS",
.dev_name = "ttyS",
.major = TTY_MAJOR,
.minor = 64,
.nr = CONFIG_ADM5120_NR_UARTS,
.cons = &adm5120_serconsole,
};
static int __init adm5120ser_init(void)
{
int ret, i;
ret = uart_register_driver(&adm5120ser_reg);
if (!ret) {
for (i = 0; i < CONFIG_ADM5120_NR_UARTS; i++)
uart_add_one_port(&adm5120ser_reg, &adm5120ser_ports[i]);
}
return ret;
}
__initcall(adm5120ser_init);