Linux-2.6.33.2/drivers/serial/clps711x.c
/*
* linux/drivers/char/clps711x.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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#if defined(CONFIG_SERIAL_CLPS711X_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/hardware/clps7111.h>
#define UART_NR 2
#define SERIAL_CLPS711X_MAJOR 204
#define SERIAL_CLPS711X_MINOR 40
#define SERIAL_CLPS711X_NR UART_NR
/*
* We use the relevant SYSCON register as a base address for these ports.
*/
#define UBRLCR(port) ((port)->iobase + UBRLCR1 - SYSCON1)
#define UARTDR(port) ((port)->iobase + UARTDR1 - SYSCON1)
#define SYSFLG(port) ((port)->iobase + SYSFLG1 - SYSCON1)
#define SYSCON(port) ((port)->iobase + SYSCON1 - SYSCON1)
#define TX_IRQ(port) ((port)->irq)
#define RX_IRQ(port) ((port)->irq + 1)
#define UART_ANY_ERR (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR)
#define tx_enabled(port) ((port)->unused[0])
static void clps711xuart_stop_tx(struct uart_port *port)
{
if (tx_enabled(port)) {
disable_irq(TX_IRQ(port));
tx_enabled(port) = 0;
}
}
static void clps711xuart_start_tx(struct uart_port *port)
{
if (!tx_enabled(port)) {
enable_irq(TX_IRQ(port));
tx_enabled(port) = 1;
}
}
static void clps711xuart_stop_rx(struct uart_port *port)
{
disable_irq(RX_IRQ(port));
}
static void clps711xuart_enable_ms(struct uart_port *port)
{
}
static irqreturn_t clps711xuart_int_rx(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct tty_struct *tty = port->state->port.tty;
unsigned int status, ch, flg;
status = clps_readl(SYSFLG(port));
while (!(status & SYSFLG_URXFE)) {
ch = clps_readl(UARTDR(port));
port->icount.rx++;
flg = TTY_NORMAL;
/*
* Note that the error handling code is
* out of the main execution path
*/
if (unlikely(ch & UART_ANY_ERR)) {
if (ch & UARTDR_PARERR)
port->icount.parity++;
else if (ch & UARTDR_FRMERR)
port->icount.frame++;
if (ch & UARTDR_OVERR)
port->icount.overrun++;
ch &= port->read_status_mask;
if (ch & UARTDR_PARERR)
flg = TTY_PARITY;
else if (ch & UARTDR_FRMERR)
flg = TTY_FRAME;
#ifdef SUPPORT_SYSRQ
port->sysrq = 0;
#endif
}
if (uart_handle_sysrq_char(port, ch))
goto ignore_char;
/*
* CHECK: does overrun affect the current character?
* ASSUMPTION: it does not.
*/
uart_insert_char(port, ch, UARTDR_OVERR, ch, flg);
ignore_char:
status = clps_readl(SYSFLG(port));
}
tty_flip_buffer_push(tty);
return IRQ_HANDLED;
}
static irqreturn_t clps711xuart_int_tx(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct circ_buf *xmit = &port->state->xmit;
int count;
if (port->x_char) {
clps_writel(port->x_char, UARTDR(port));
port->icount.tx++;
port->x_char = 0;
return IRQ_HANDLED;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
clps711xuart_stop_tx(port);
return IRQ_HANDLED;
}
count = port->fifosize >> 1;
do {
clps_writel(xmit->buf[xmit->tail], UARTDR(port));
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))
clps711xuart_stop_tx(port);
return IRQ_HANDLED;
}
static unsigned int clps711xuart_tx_empty(struct uart_port *port)
{
unsigned int status = clps_readl(SYSFLG(port));
return status & SYSFLG_UBUSY ? 0 : TIOCSER_TEMT;
}
static unsigned int clps711xuart_get_mctrl(struct uart_port *port)
{
unsigned int port_addr;
unsigned int result = 0;
unsigned int status;
port_addr = SYSFLG(port);
if (port_addr == SYSFLG1) {
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;
}
return result;
}
static void
clps711xuart_set_mctrl_null(struct uart_port *port, unsigned int mctrl)
{
}
static void clps711xuart_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 == -1)
ubrlcr |= UBRLCR_BREAK;
else
ubrlcr &= ~UBRLCR_BREAK;
clps_writel(ubrlcr, UBRLCR(port));
spin_unlock_irqrestore(&port->lock, flags);
}
static int clps711xuart_startup(struct uart_port *port)
{
unsigned int syscon;
int retval;
tx_enabled(port) = 1;
/*
* Allocate the IRQs
*/
retval = request_irq(TX_IRQ(port), clps711xuart_int_tx, 0,
"clps711xuart_tx", port);
if (retval)
return retval;
retval = request_irq(RX_IRQ(port), clps711xuart_int_rx, 0,
"clps711xuart_rx", port);
if (retval) {
free_irq(TX_IRQ(port), port);
return retval;
}
/*
* enable the port
*/
syscon = clps_readl(SYSCON(port));
syscon |= SYSCON_UARTEN;
clps_writel(syscon, SYSCON(port));
return 0;
}
static void clps711xuart_shutdown(struct uart_port *port)
{
unsigned int ubrlcr, syscon;
/*
* Free the interrupt
*/
free_irq(TX_IRQ(port), port); /* TX interrupt */
free_irq(RX_IRQ(port), port); /* RX interrupt */
/*
* disable the port
*/
syscon = clps_readl(SYSCON(port));
syscon &= ~SYSCON_UARTEN;
clps_writel(syscon, SYSCON(port));
/*
* disable break condition and fifos
*/
ubrlcr = clps_readl(UBRLCR(port));
ubrlcr &= ~(UBRLCR_FIFOEN | UBRLCR_BREAK);
clps_writel(ubrlcr, UBRLCR(port));
}
static void
clps711xuart_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
unsigned int ubrlcr, baud, quot;
unsigned long flags;
/*
* We don't implement CREAD.
*/
termios->c_cflag |= CREAD;
/*
* Ask the core to calculate the divisor for us.
*/
baud = uart_get_baud_rate(port, termios, old, 0, 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;
default: // CS8
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;
}
if (port->fifosize > 1)
ubrlcr |= UBRLCR_FIFOEN;
spin_lock_irqsave(&port->lock, flags);
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
port->read_status_mask = UARTDR_OVERR;
if (termios->c_iflag & INPCK)
port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= UARTDR_FRMERR | UARTDR_PARERR;
if (termios->c_iflag & IGNBRK) {
/*
* If we're ignoring parity and break indicators,
* ignore overruns to (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= UARTDR_OVERR;
}
quot -= 1;
clps_writel(ubrlcr | quot, UBRLCR(port));
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *clps711xuart_type(struct uart_port *port)
{
return port->type == PORT_CLPS711X ? "CLPS711x" : NULL;
}
/*
* Configure/autoconfigure the port.
*/
static void clps711xuart_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE)
port->type = PORT_CLPS711X;
}
static void clps711xuart_release_port(struct uart_port *port)
{
}
static int clps711xuart_request_port(struct uart_port *port)
{
return 0;
}
static struct uart_ops clps711x_pops = {
.tx_empty = clps711xuart_tx_empty,
.set_mctrl = clps711xuart_set_mctrl_null,
.get_mctrl = clps711xuart_get_mctrl,
.stop_tx = clps711xuart_stop_tx,
.start_tx = clps711xuart_start_tx,
.stop_rx = clps711xuart_stop_rx,
.enable_ms = clps711xuart_enable_ms,
.break_ctl = clps711xuart_break_ctl,
.startup = clps711xuart_startup,
.shutdown = clps711xuart_shutdown,
.set_termios = clps711xuart_set_termios,
.type = clps711xuart_type,
.config_port = clps711xuart_config_port,
.release_port = clps711xuart_release_port,
.request_port = clps711xuart_request_port,
};
static struct uart_port clps711x_ports[UART_NR] = {
{
.iobase = SYSCON1,
.irq = IRQ_UTXINT1, /* IRQ_URXINT1, IRQ_UMSINT */
.uartclk = 3686400,
.fifosize = 16,
.ops = &clps711x_pops,
.line = 0,
.flags = UPF_BOOT_AUTOCONF,
},
{
.iobase = SYSCON2,
.irq = IRQ_UTXINT2, /* IRQ_URXINT2 */
.uartclk = 3686400,
.fifosize = 16,
.ops = &clps711x_pops,
.line = 1,
.flags = UPF_BOOT_AUTOCONF,
}
};
#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
static void clps711xuart_console_putchar(struct uart_port *port, int ch)
{
while (clps_readl(SYSFLG(port)) & SYSFLG_UTXFF)
barrier();
clps_writel(ch, UARTDR(port));
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*
* The console_lock must be held when we get here.
*
* Note that this is called with interrupts already disabled
*/
static void
clps711xuart_console_write(struct console *co, const char *s,
unsigned int count)
{
struct uart_port *port = clps711x_ports + co->index;
unsigned int status, syscon;
/*
* Ensure that the port is enabled.
*/
syscon = clps_readl(SYSCON(port));
clps_writel(syscon | SYSCON_UARTEN, SYSCON(port));
uart_console_write(port, s, count, clps711xuart_console_putchar);
/*
* Finally, wait for transmitter to become empty
* and restore the uart state.
*/
do {
status = clps_readl(SYSFLG(port));
} while (status & SYSFLG_UBUSY);
clps_writel(syscon, SYSCON(port));
}
static void __init
clps711xuart_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 __init clps711xuart_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 38400;
int bits = 8;
int parity = 'n';
int flow = 'n';
/*
* Check whether an invalid uart number has been specified, and
* if so, search for the first available port that does have
* console support.
*/
port = uart_get_console(clps711x_ports, UART_NR, co);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
clps711xuart_console_get_options(port, &baud, &parity, &bits);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver clps711x_reg;
static struct console clps711x_console = {
.name = "ttyCL",
.write = clps711xuart_console_write,
.device = uart_console_device,
.setup = clps711xuart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &clps711x_reg,
};
static int __init clps711xuart_console_init(void)
{
register_console(&clps711x_console);
return 0;
}
console_initcall(clps711xuart_console_init);
#define CLPS711X_CONSOLE &clps711x_console
#else
#define CLPS711X_CONSOLE NULL
#endif
static struct uart_driver clps711x_reg = {
.driver_name = "ttyCL",
.dev_name = "ttyCL",
.major = SERIAL_CLPS711X_MAJOR,
.minor = SERIAL_CLPS711X_MINOR,
.nr = UART_NR,
.cons = CLPS711X_CONSOLE,
};
static int __init clps711xuart_init(void)
{
int ret, i;
printk(KERN_INFO "Serial: CLPS711x driver\n");
ret = uart_register_driver(&clps711x_reg);
if (ret)
return ret;
for (i = 0; i < UART_NR; i++)
uart_add_one_port(&clps711x_reg, &clps711x_ports[i]);
return 0;
}
static void __exit clps711xuart_exit(void)
{
int i;
for (i = 0; i < UART_NR; i++)
uart_remove_one_port(&clps711x_reg, &clps711x_ports[i]);
uart_unregister_driver(&clps711x_reg);
}
module_init(clps711xuart_init);
module_exit(clps711xuart_exit);
MODULE_AUTHOR("Deep Blue Solutions Ltd");
MODULE_DESCRIPTION("CLPS-711x generic serial driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV(SERIAL_CLPS711X_MAJOR, SERIAL_CLPS711X_MINOR);