Linux-2.6.33.2/drivers/serial/serial_ks8695.c
/*
* drivers/serial/serial_ks8695.c
*
* Driver for KS8695 serial ports
*
* Based on drivers/serial/serial_amba.c, by Kam Lee.
*
* Copyright 2002-2005 Micrel Inc.
*
* 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.
*
*/
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/serial.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/device.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mach/irq.h>
#include <mach/regs-uart.h>
#include <mach/regs-irq.h>
#if defined(CONFIG_SERIAL_KS8695_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/serial_core.h>
#define SERIAL_KS8695_MAJOR 204
#define SERIAL_KS8695_MINOR 16
#define SERIAL_KS8695_DEVNAME "ttyAM"
#define SERIAL_KS8695_NR 1
/*
* Access macros for the KS8695 UART
*/
#define UART_GET_CHAR(p) (__raw_readl((p)->membase + KS8695_URRB) & 0xFF)
#define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + KS8695_URTH)
#define UART_GET_FCR(p) __raw_readl((p)->membase + KS8695_URFC)
#define UART_PUT_FCR(p, c) __raw_writel((c), (p)->membase + KS8695_URFC)
#define UART_GET_MSR(p) __raw_readl((p)->membase + KS8695_URMS)
#define UART_GET_LSR(p) __raw_readl((p)->membase + KS8695_URLS)
#define UART_GET_LCR(p) __raw_readl((p)->membase + KS8695_URLC)
#define UART_PUT_LCR(p, c) __raw_writel((c), (p)->membase + KS8695_URLC)
#define UART_GET_MCR(p) __raw_readl((p)->membase + KS8695_URMC)
#define UART_PUT_MCR(p, c) __raw_writel((c), (p)->membase + KS8695_URMC)
#define UART_GET_BRDR(p) __raw_readl((p)->membase + KS8695_URBD)
#define UART_PUT_BRDR(p, c) __raw_writel((c), (p)->membase + KS8695_URBD)
#define KS8695_CLR_TX_INT() __raw_writel(1 << KS8695_IRQ_UART_TX, KS8695_IRQ_VA + KS8695_INTST)
#define UART_DUMMY_LSR_RX 0x100
#define UART_PORT_SIZE (KS8695_USR - KS8695_URRB + 4)
static inline int tx_enabled(struct uart_port *port)
{
return port->unused[0] & 1;
}
static inline int rx_enabled(struct uart_port *port)
{
return port->unused[0] & 2;
}
static inline int ms_enabled(struct uart_port *port)
{
return port->unused[0] & 4;
}
static inline void ms_enable(struct uart_port *port, int enabled)
{
if(enabled)
port->unused[0] |= 4;
else
port->unused[0] &= ~4;
}
static inline void rx_enable(struct uart_port *port, int enabled)
{
if(enabled)
port->unused[0] |= 2;
else
port->unused[0] &= ~2;
}
static inline void tx_enable(struct uart_port *port, int enabled)
{
if(enabled)
port->unused[0] |= 1;
else
port->unused[0] &= ~1;
}
#ifdef SUPPORT_SYSRQ
static struct console ks8695_console;
#endif
static void ks8695uart_stop_tx(struct uart_port *port)
{
if (tx_enabled(port)) {
/* use disable_irq_nosync() and not disable_irq() to avoid self
* imposed deadlock by not waiting for irq handler to end,
* since this ks8695uart_stop_tx() is called from interrupt context.
*/
disable_irq_nosync(KS8695_IRQ_UART_TX);
tx_enable(port, 0);
}
}
static void ks8695uart_start_tx(struct uart_port *port)
{
if (!tx_enabled(port)) {
enable_irq(KS8695_IRQ_UART_TX);
tx_enable(port, 1);
}
}
static void ks8695uart_stop_rx(struct uart_port *port)
{
if (rx_enabled(port)) {
disable_irq(KS8695_IRQ_UART_RX);
rx_enable(port, 0);
}
}
static void ks8695uart_enable_ms(struct uart_port *port)
{
if (!ms_enabled(port)) {
enable_irq(KS8695_IRQ_UART_MODEM_STATUS);
ms_enable(port,1);
}
}
static void ks8695uart_disable_ms(struct uart_port *port)
{
if (ms_enabled(port)) {
disable_irq(KS8695_IRQ_UART_MODEM_STATUS);
ms_enable(port,0);
}
}
static irqreturn_t ks8695uart_rx_chars(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct tty_struct *tty = port->state->port.tty;
unsigned int status, ch, lsr, flg, max_count = 256;
status = UART_GET_LSR(port); /* clears pending LSR interrupts */
while ((status & URLS_URDR) && max_count--) {
ch = UART_GET_CHAR(port);
flg = TTY_NORMAL;
port->icount.rx++;
/*
* Note that the error handling code is
* out of the main execution path
*/
lsr = UART_GET_LSR(port) | UART_DUMMY_LSR_RX;
if (unlikely(lsr & (URLS_URBI | URLS_URPE | URLS_URFE | URLS_URROE))) {
if (lsr & URLS_URBI) {
lsr &= ~(URLS_URFE | URLS_URPE);
port->icount.brk++;
if (uart_handle_break(port))
goto ignore_char;
}
if (lsr & URLS_URPE)
port->icount.parity++;
if (lsr & URLS_URFE)
port->icount.frame++;
if (lsr & URLS_URROE)
port->icount.overrun++;
lsr &= port->read_status_mask;
if (lsr & URLS_URBI)
flg = TTY_BREAK;
else if (lsr & URLS_URPE)
flg = TTY_PARITY;
else if (lsr & URLS_URFE)
flg = TTY_FRAME;
}
if (uart_handle_sysrq_char(port, ch))
goto ignore_char;
uart_insert_char(port, lsr, URLS_URROE, ch, flg);
ignore_char:
status = UART_GET_LSR(port);
}
tty_flip_buffer_push(tty);
return IRQ_HANDLED;
}
static irqreturn_t ks8695uart_tx_chars(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct circ_buf *xmit = &port->state->xmit;
unsigned int count;
if (port->x_char) {
KS8695_CLR_TX_INT();
UART_PUT_CHAR(port, port->x_char);
port->icount.tx++;
port->x_char = 0;
return IRQ_HANDLED;
}
if (uart_tx_stopped(port) || uart_circ_empty(xmit)) {
ks8695uart_stop_tx(port);
return IRQ_HANDLED;
}
count = 16; /* fifo size */
while (!uart_circ_empty(xmit) && (count-- > 0)) {
KS8695_CLR_TX_INT();
UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (uart_circ_empty(xmit))
ks8695uart_stop_tx(port);
return IRQ_HANDLED;
}
static irqreturn_t ks8695uart_modem_status(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
unsigned int status;
/*
* clear modem interrupt by reading MSR
*/
status = UART_GET_MSR(port);
if (status & URMS_URDDCD)
uart_handle_dcd_change(port, status & URMS_URDDCD);
if (status & URMS_URDDST)
port->icount.dsr++;
if (status & URMS_URDCTS)
uart_handle_cts_change(port, status & URMS_URDCTS);
if (status & URMS_URTERI)
port->icount.rng++;
wake_up_interruptible(&port->state->port.delta_msr_wait);
return IRQ_HANDLED;
}
static unsigned int ks8695uart_tx_empty(struct uart_port *port)
{
return (UART_GET_LSR(port) & URLS_URTE) ? TIOCSER_TEMT : 0;
}
static unsigned int ks8695uart_get_mctrl(struct uart_port *port)
{
unsigned int result = 0;
unsigned int status;
status = UART_GET_MSR(port);
if (status & URMS_URDCD)
result |= TIOCM_CAR;
if (status & URMS_URDSR)
result |= TIOCM_DSR;
if (status & URMS_URCTS)
result |= TIOCM_CTS;
if (status & URMS_URRI)
result |= TIOCM_RI;
return result;
}
static void ks8695uart_set_mctrl(struct uart_port *port, u_int mctrl)
{
unsigned int mcr;
mcr = UART_GET_MCR(port);
if (mctrl & TIOCM_RTS)
mcr |= URMC_URRTS;
else
mcr &= ~URMC_URRTS;
if (mctrl & TIOCM_DTR)
mcr |= URMC_URDTR;
else
mcr &= ~URMC_URDTR;
UART_PUT_MCR(port, mcr);
}
static void ks8695uart_break_ctl(struct uart_port *port, int break_state)
{
unsigned int lcr;
lcr = UART_GET_LCR(port);
if (break_state == -1)
lcr |= URLC_URSBC;
else
lcr &= ~URLC_URSBC;
UART_PUT_LCR(port, lcr);
}
static int ks8695uart_startup(struct uart_port *port)
{
int retval;
set_irq_flags(KS8695_IRQ_UART_TX, IRQF_VALID | IRQF_NOAUTOEN);
tx_enable(port, 0);
rx_enable(port, 1);
ms_enable(port, 1);
/*
* Allocate the IRQ
*/
retval = request_irq(KS8695_IRQ_UART_TX, ks8695uart_tx_chars, IRQF_DISABLED, "UART TX", port);
if (retval)
goto err_tx;
retval = request_irq(KS8695_IRQ_UART_RX, ks8695uart_rx_chars, IRQF_DISABLED, "UART RX", port);
if (retval)
goto err_rx;
retval = request_irq(KS8695_IRQ_UART_LINE_STATUS, ks8695uart_rx_chars, IRQF_DISABLED, "UART LineStatus", port);
if (retval)
goto err_ls;
retval = request_irq(KS8695_IRQ_UART_MODEM_STATUS, ks8695uart_modem_status, IRQF_DISABLED, "UART ModemStatus", port);
if (retval)
goto err_ms;
return 0;
err_ms:
free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
err_ls:
free_irq(KS8695_IRQ_UART_RX, port);
err_rx:
free_irq(KS8695_IRQ_UART_TX, port);
err_tx:
return retval;
}
static void ks8695uart_shutdown(struct uart_port *port)
{
/*
* Free the interrupt
*/
free_irq(KS8695_IRQ_UART_RX, port);
free_irq(KS8695_IRQ_UART_TX, port);
free_irq(KS8695_IRQ_UART_MODEM_STATUS, port);
free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
/* disable break condition and fifos */
UART_PUT_LCR(port, UART_GET_LCR(port) & ~URLC_URSBC);
UART_PUT_FCR(port, UART_GET_FCR(port) & ~URFC_URFE);
}
static void ks8695uart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old)
{
unsigned int lcr, fcr = 0;
unsigned long flags;
unsigned int baud, quot;
/*
* 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:
lcr = URCL_5;
break;
case CS6:
lcr = URCL_6;
break;
case CS7:
lcr = URCL_7;
break;
default:
lcr = URCL_8;
break;
}
/* stop bits */
if (termios->c_cflag & CSTOPB)
lcr |= URLC_URSB;
/* parity */
if (termios->c_cflag & PARENB) {
if (termios->c_cflag & CMSPAR) { /* Mark or Space parity */
if (termios->c_cflag & PARODD)
lcr |= URPE_MARK;
else
lcr |= URPE_SPACE;
}
else if (termios->c_cflag & PARODD)
lcr |= URPE_ODD;
else
lcr |= URPE_EVEN;
}
if (port->fifosize > 1)
fcr = URFC_URFRT_8 | URFC_URTFR | URFC_URRFR | URFC_URFE;
spin_lock_irqsave(&port->lock, flags);
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
port->read_status_mask = URLS_URROE;
if (termios->c_iflag & INPCK)
port->read_status_mask |= (URLS_URFE | URLS_URPE);
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= URLS_URBI;
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= (URLS_URFE | URLS_URPE);
if (termios->c_iflag & IGNBRK) {
port->ignore_status_mask |= URLS_URBI;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= URLS_URROE;
}
/*
* Ignore all characters if CREAD is not set.
*/
if ((termios->c_cflag & CREAD) == 0)
port->ignore_status_mask |= UART_DUMMY_LSR_RX;
/* first, disable everything */
if (UART_ENABLE_MS(port, termios->c_cflag))
ks8695uart_enable_ms(port);
else
ks8695uart_disable_ms(port);
/* Set baud rate */
UART_PUT_BRDR(port, quot);
UART_PUT_LCR(port, lcr);
UART_PUT_FCR(port, fcr);
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *ks8695uart_type(struct uart_port *port)
{
return port->type == PORT_KS8695 ? "KS8695" : NULL;
}
/*
* Release the memory region(s) being used by 'port'
*/
static void ks8695uart_release_port(struct uart_port *port)
{
release_mem_region(port->mapbase, UART_PORT_SIZE);
}
/*
* Request the memory region(s) being used by 'port'
*/
static int ks8695uart_request_port(struct uart_port *port)
{
return request_mem_region(port->mapbase, UART_PORT_SIZE,
"serial_ks8695") != NULL ? 0 : -EBUSY;
}
/*
* Configure/autoconfigure the port.
*/
static void ks8695uart_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE) {
port->type = PORT_KS8695;
ks8695uart_request_port(port);
}
}
/*
* verify the new serial_struct (for TIOCSSERIAL).
*/
static int ks8695uart_verify_port(struct uart_port *port, struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_KS8695)
ret = -EINVAL;
if (ser->irq != port->irq)
ret = -EINVAL;
if (ser->baud_base < 9600)
ret = -EINVAL;
return ret;
}
static struct uart_ops ks8695uart_pops = {
.tx_empty = ks8695uart_tx_empty,
.set_mctrl = ks8695uart_set_mctrl,
.get_mctrl = ks8695uart_get_mctrl,
.stop_tx = ks8695uart_stop_tx,
.start_tx = ks8695uart_start_tx,
.stop_rx = ks8695uart_stop_rx,
.enable_ms = ks8695uart_enable_ms,
.break_ctl = ks8695uart_break_ctl,
.startup = ks8695uart_startup,
.shutdown = ks8695uart_shutdown,
.set_termios = ks8695uart_set_termios,
.type = ks8695uart_type,
.release_port = ks8695uart_release_port,
.request_port = ks8695uart_request_port,
.config_port = ks8695uart_config_port,
.verify_port = ks8695uart_verify_port,
};
static struct uart_port ks8695uart_ports[SERIAL_KS8695_NR] = {
{
.membase = (void *) KS8695_UART_VA,
.mapbase = KS8695_UART_VA,
.iotype = SERIAL_IO_MEM,
.irq = KS8695_IRQ_UART_TX,
.uartclk = KS8695_CLOCK_RATE * 16,
.fifosize = 16,
.ops = &ks8695uart_pops,
.flags = ASYNC_BOOT_AUTOCONF,
.line = 0,
}
};
#ifdef CONFIG_SERIAL_KS8695_CONSOLE
static void ks8695_console_putchar(struct uart_port *port, int ch)
{
while (!(UART_GET_LSR(port) & URLS_URTHRE))
barrier();
UART_PUT_CHAR(port, ch);
}
static void ks8695_console_write(struct console *co, const char *s, u_int count)
{
struct uart_port *port = ks8695uart_ports + co->index;
uart_console_write(port, s, count, ks8695_console_putchar);
}
static void __init ks8695_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
{
unsigned int lcr;
lcr = UART_GET_LCR(port);
switch (lcr & URLC_PARITY) {
case URPE_ODD:
*parity = 'o';
break;
case URPE_EVEN:
*parity = 'e';
break;
default:
*parity = 'n';
}
switch (lcr & URLC_URCL) {
case URCL_5:
*bits = 5;
break;
case URCL_6:
*bits = 6;
break;
case URCL_7:
*bits = 7;
break;
default:
*bits = 8;
}
*baud = port->uartclk / (UART_GET_BRDR(port) & 0x0FFF);
*baud /= 16;
*baud &= 0xFFFFFFF0;
}
static int __init ks8695_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 115200;
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(ks8695uart_ports, SERIAL_KS8695_NR, co);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
ks8695_console_get_options(port, &baud, &parity, &bits);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver ks8695_reg;
static struct console ks8695_console = {
.name = SERIAL_KS8695_DEVNAME,
.write = ks8695_console_write,
.device = uart_console_device,
.setup = ks8695_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &ks8695_reg,
};
static int __init ks8695_console_init(void)
{
register_console(&ks8695_console);
return 0;
}
console_initcall(ks8695_console_init);
#define KS8695_CONSOLE &ks8695_console
#else
#define KS8695_CONSOLE NULL
#endif
static struct uart_driver ks8695_reg = {
.owner = THIS_MODULE,
.driver_name = "serial_ks8695",
.dev_name = SERIAL_KS8695_DEVNAME,
.major = SERIAL_KS8695_MAJOR,
.minor = SERIAL_KS8695_MINOR,
.nr = SERIAL_KS8695_NR,
.cons = KS8695_CONSOLE,
};
static int __init ks8695uart_init(void)
{
int i, ret;
printk(KERN_INFO "Serial: Micrel KS8695 UART driver\n");
ret = uart_register_driver(&ks8695_reg);
if (ret)
return ret;
for (i = 0; i < SERIAL_KS8695_NR; i++)
uart_add_one_port(&ks8695_reg, &ks8695uart_ports[0]);
return 0;
}
static void __exit ks8695uart_exit(void)
{
int i;
for (i = 0; i < SERIAL_KS8695_NR; i++)
uart_remove_one_port(&ks8695_reg, &ks8695uart_ports[0]);
uart_unregister_driver(&ks8695_reg);
}
module_init(ks8695uart_init);
module_exit(ks8695uart_exit);
MODULE_DESCRIPTION("KS8695 serial port driver");
MODULE_AUTHOR("Micrel Inc.");
MODULE_LICENSE("GPL");