- 根目录:
- drivers
- tty
- serial
- sc26xx.c
/*
* SC268xx.c: Serial driver for Philiphs SC2681/SC2692 devices.
*
* Copyright (C) 2006,2007 Thomas Bogendörfer (tsbogend@alpha.franken.de)
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/circ_buf.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/irq.h>
#if defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/serial_core.h>
#define SC26XX_MAJOR 204
#define SC26XX_MINOR_START 205
#define SC26XX_NR 2
struct uart_sc26xx_port {
struct uart_port port[2];
u8 dsr_mask[2];
u8 cts_mask[2];
u8 dcd_mask[2];
u8 ri_mask[2];
u8 dtr_mask[2];
u8 rts_mask[2];
u8 imr;
};
/* register common to both ports */
#define RD_ISR 0x14
#define RD_IPR 0x34
#define WR_ACR 0x10
#define WR_IMR 0x14
#define WR_OPCR 0x34
#define WR_OPR_SET 0x38
#define WR_OPR_CLR 0x3C
/* access common register */
#define READ_SC(p, r) readb((p)->membase + RD_##r)
#define WRITE_SC(p, r, v) writeb((v), (p)->membase + WR_##r)
/* register per port */
#define RD_PORT_MRx 0x00
#define RD_PORT_SR 0x04
#define RD_PORT_RHR 0x0c
#define WR_PORT_MRx 0x00
#define WR_PORT_CSR 0x04
#define WR_PORT_CR 0x08
#define WR_PORT_THR 0x0c
/* SR bits */
#define SR_BREAK (1 << 7)
#define SR_FRAME (1 << 6)
#define SR_PARITY (1 << 5)
#define SR_OVERRUN (1 << 4)
#define SR_TXRDY (1 << 2)
#define SR_RXRDY (1 << 0)
#define CR_RES_MR (1 << 4)
#define CR_RES_RX (2 << 4)
#define CR_RES_TX (3 << 4)
#define CR_STRT_BRK (6 << 4)
#define CR_STOP_BRK (7 << 4)
#define CR_DIS_TX (1 << 3)
#define CR_ENA_TX (1 << 2)
#define CR_DIS_RX (1 << 1)
#define CR_ENA_RX (1 << 0)
/* ISR bits */
#define ISR_RXRDYB (1 << 5)
#define ISR_TXRDYB (1 << 4)
#define ISR_RXRDYA (1 << 1)
#define ISR_TXRDYA (1 << 0)
/* IMR bits */
#define IMR_RXRDY (1 << 1)
#define IMR_TXRDY (1 << 0)
/* access port register */
static inline u8 read_sc_port(struct uart_port *p, u8 reg)
{
return readb(p->membase + p->line * 0x20 + reg);
}
static inline void write_sc_port(struct uart_port *p, u8 reg, u8 val)
{
writeb(val, p->membase + p->line * 0x20 + reg);
}
#define READ_SC_PORT(p, r) read_sc_port(p, RD_PORT_##r)
#define WRITE_SC_PORT(p, r, v) write_sc_port(p, WR_PORT_##r, v)
static void sc26xx_enable_irq(struct uart_port *port, int mask)
{
struct uart_sc26xx_port *up;
int line = port->line;
port -= line;
up = container_of(port, struct uart_sc26xx_port, port[0]);
up->imr |= mask << (line * 4);
WRITE_SC(port, IMR, up->imr);
}
static void sc26xx_disable_irq(struct uart_port *port, int mask)
{
struct uart_sc26xx_port *up;
int line = port->line;
port -= line;
up = container_of(port, struct uart_sc26xx_port, port[0]);
up->imr &= ~(mask << (line * 4));
WRITE_SC(port, IMR, up->imr);
}
static struct tty_struct *receive_chars(struct uart_port *port)
{
struct tty_struct *tty = NULL;
int limit = 10000;
unsigned char ch;
char flag;
u8 status;
if (port->state != NULL) /* Unopened serial console */
tty = port->state->port.tty;
while (limit-- > 0) {
status = READ_SC_PORT(port, SR);
if (!(status & SR_RXRDY))
break;
ch = READ_SC_PORT(port, RHR);
flag = TTY_NORMAL;
port->icount.rx++;
if (unlikely(status & (SR_BREAK | SR_FRAME |
SR_PARITY | SR_OVERRUN))) {
if (status & SR_BREAK) {
status &= ~(SR_PARITY | SR_FRAME);
port->icount.brk++;
if (uart_handle_break(port))
continue;
} else if (status & SR_PARITY)
port->icount.parity++;
else if (status & SR_FRAME)
port->icount.frame++;
if (status & SR_OVERRUN)
port->icount.overrun++;
status &= port->read_status_mask;
if (status & SR_BREAK)
flag = TTY_BREAK;
else if (status & SR_PARITY)
flag = TTY_PARITY;
else if (status & SR_FRAME)
flag = TTY_FRAME;
}
if (uart_handle_sysrq_char(port, ch))
continue;
if (status & port->ignore_status_mask)
continue;
tty_insert_flip_char(tty, ch, flag);
}
return tty;
}
static void transmit_chars(struct uart_port *port)
{
struct circ_buf *xmit;
if (!port->state)
return;
xmit = &port->state->xmit;
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
sc26xx_disable_irq(port, IMR_TXRDY);
return;
}
while (!uart_circ_empty(xmit)) {
if (!(READ_SC_PORT(port, SR) & SR_TXRDY))
break;
WRITE_SC_PORT(port, THR, 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);
}
static irqreturn_t sc26xx_interrupt(int irq, void *dev_id)
{
struct uart_sc26xx_port *up = dev_id;
struct tty_struct *tty;
unsigned long flags;
u8 isr;
spin_lock_irqsave(&up->port[0].lock, flags);
tty = NULL;
isr = READ_SC(&up->port[0], ISR);
if (isr & ISR_TXRDYA)
transmit_chars(&up->port[0]);
if (isr & ISR_RXRDYA)
tty = receive_chars(&up->port[0]);
spin_unlock(&up->port[0].lock);
if (tty)
tty_flip_buffer_push(tty);
spin_lock(&up->port[1].lock);
tty = NULL;
if (isr & ISR_TXRDYB)
transmit_chars(&up->port[1]);
if (isr & ISR_RXRDYB)
tty = receive_chars(&up->port[1]);
spin_unlock_irqrestore(&up->port[1].lock, flags);
if (tty)
tty_flip_buffer_push(tty);
return IRQ_HANDLED;
}
/* port->lock is not held. */
static unsigned int sc26xx_tx_empty(struct uart_port *port)
{
return (READ_SC_PORT(port, SR) & SR_TXRDY) ? TIOCSER_TEMT : 0;
}
/* port->lock held by caller. */
static void sc26xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_sc26xx_port *up;
int line = port->line;
port -= line;
up = container_of(port, struct uart_sc26xx_port, port[0]);
if (up->dtr_mask[line]) {
if (mctrl & TIOCM_DTR)
WRITE_SC(port, OPR_SET, up->dtr_mask[line]);
else
WRITE_SC(port, OPR_CLR, up->dtr_mask[line]);
}
if (up->rts_mask[line]) {
if (mctrl & TIOCM_RTS)
WRITE_SC(port, OPR_SET, up->rts_mask[line]);
else
WRITE_SC(port, OPR_CLR, up->rts_mask[line]);
}
}
/* port->lock is held by caller and interrupts are disabled. */
static unsigned int sc26xx_get_mctrl(struct uart_port *port)
{
struct uart_sc26xx_port *up;
int line = port->line;
unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
u8 ipr;
port -= line;
up = container_of(port, struct uart_sc26xx_port, port[0]);
ipr = READ_SC(port, IPR) ^ 0xff;
if (up->dsr_mask[line]) {
mctrl &= ~TIOCM_DSR;
mctrl |= ipr & up->dsr_mask[line] ? TIOCM_DSR : 0;
}
if (up->cts_mask[line]) {
mctrl &= ~TIOCM_CTS;
mctrl |= ipr & up->cts_mask[line] ? TIOCM_CTS : 0;
}
if (up->dcd_mask[line]) {
mctrl &= ~TIOCM_CAR;
mctrl |= ipr & up->dcd_mask[line] ? TIOCM_CAR : 0;
}
if (up->ri_mask[line]) {
mctrl &= ~TIOCM_RNG;
mctrl |= ipr & up->ri_mask[line] ? TIOCM_RNG : 0;
}
return mctrl;
}
/* port->lock held by caller. */
static void sc26xx_stop_tx(struct uart_port *port)
{
return;
}
/* port->lock held by caller. */
static void sc26xx_start_tx(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
while (!uart_circ_empty(xmit)) {
if (!(READ_SC_PORT(port, SR) & SR_TXRDY)) {
sc26xx_enable_irq(port, IMR_TXRDY);
break;
}
WRITE_SC_PORT(port, THR, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
}
}
/* port->lock held by caller. */
static void sc26xx_stop_rx(struct uart_port *port)
{
}
/* port->lock held by caller. */
static void sc26xx_enable_ms(struct uart_port *port)
{
}
/* port->lock is not held. */
static void sc26xx_break_ctl(struct uart_port *port, int break_state)
{
if (break_state == -1)
WRITE_SC_PORT(port, CR, CR_STRT_BRK);
else
WRITE_SC_PORT(port, CR, CR_STOP_BRK);
}
/* port->lock is not held. */
static int sc26xx_startup(struct uart_port *port)
{
sc26xx_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
WRITE_SC(port, OPCR, 0);
/* reset tx and rx */
WRITE_SC_PORT(port, CR, CR_RES_RX);
WRITE_SC_PORT(port, CR, CR_RES_TX);
/* start rx/tx */
WRITE_SC_PORT(port, CR, CR_ENA_TX | CR_ENA_RX);
/* enable irqs */
sc26xx_enable_irq(port, IMR_RXRDY);
return 0;
}
/* port->lock is not held. */
static void sc26xx_shutdown(struct uart_port *port)
{
/* disable interrupst */
sc26xx_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
/* stop tx/rx */
WRITE_SC_PORT(port, CR, CR_DIS_TX | CR_DIS_RX);
}
/* port->lock is not held. */
static void sc26xx_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
unsigned int quot = uart_get_divisor(port, baud);
unsigned int iflag, cflag;
unsigned long flags;
u8 mr1, mr2, csr;
spin_lock_irqsave(&port->lock, flags);
while ((READ_SC_PORT(port, SR) & ((1 << 3) | (1 << 2))) != 0xc)
udelay(2);
WRITE_SC_PORT(port, CR, CR_DIS_TX | CR_DIS_RX);
iflag = termios->c_iflag;
cflag = termios->c_cflag;
port->read_status_mask = SR_OVERRUN;
if (iflag & INPCK)
port->read_status_mask |= SR_PARITY | SR_FRAME;
if (iflag & (BRKINT | PARMRK))
port->read_status_mask |= SR_BREAK;
port->ignore_status_mask = 0;
if (iflag & IGNBRK)
port->ignore_status_mask |= SR_BREAK;
if ((cflag & CREAD) == 0)
port->ignore_status_mask |= SR_BREAK | SR_FRAME |
SR_PARITY | SR_OVERRUN;
switch (cflag & CSIZE) {
case CS5:
mr1 = 0x00;
break;
case CS6:
mr1 = 0x01;
break;
case CS7:
mr1 = 0x02;
break;
default:
case CS8:
mr1 = 0x03;
break;
}
mr2 = 0x07;
if (cflag & CSTOPB)
mr2 = 0x0f;
if (cflag & PARENB) {
if (cflag & PARODD)
mr1 |= (1 << 2);
} else
mr1 |= (2 << 3);
switch (baud) {
case 50:
csr = 0x00;
break;
case 110:
csr = 0x11;
break;
case 134:
csr = 0x22;
break;
case 200:
csr = 0x33;
break;
case 300:
csr = 0x44;
break;
case 600:
csr = 0x55;
break;
case 1200:
csr = 0x66;
break;
case 2400:
csr = 0x88;
break;
case 4800:
csr = 0x99;
break;
default:
case 9600:
csr = 0xbb;
break;
case 19200:
csr = 0xcc;
break;
}
WRITE_SC_PORT(port, CR, CR_RES_MR);
WRITE_SC_PORT(port, MRx, mr1);
WRITE_SC_PORT(port, MRx, mr2);
WRITE_SC(port, ACR, 0x80);
WRITE_SC_PORT(port, CSR, csr);
/* reset tx and rx */
WRITE_SC_PORT(port, CR, CR_RES_RX);
WRITE_SC_PORT(port, CR, CR_RES_TX);
WRITE_SC_PORT(port, CR, CR_ENA_TX | CR_ENA_RX);
while ((READ_SC_PORT(port, SR) & ((1 << 3) | (1 << 2))) != 0xc)
udelay(2);
/* XXX */
uart_update_timeout(port, cflag,
(port->uartclk / (16 * quot)));
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *sc26xx_type(struct uart_port *port)
{
return "SC26XX";
}
static void sc26xx_release_port(struct uart_port *port)
{
}
static int sc26xx_request_port(struct uart_port *port)
{
return 0;
}
static void sc26xx_config_port(struct uart_port *port, int flags)
{
}
static int sc26xx_verify_port(struct uart_port *port, struct serial_struct *ser)
{
return -EINVAL;
}
static struct uart_ops sc26xx_ops = {
.tx_empty = sc26xx_tx_empty,
.set_mctrl = sc26xx_set_mctrl,
.get_mctrl = sc26xx_get_mctrl,
.stop_tx = sc26xx_stop_tx,
.start_tx = sc26xx_start_tx,
.stop_rx = sc26xx_stop_rx,
.enable_ms = sc26xx_enable_ms,
.break_ctl = sc26xx_break_ctl,
.startup = sc26xx_startup,
.shutdown = sc26xx_shutdown,
.set_termios = sc26xx_set_termios,
.type = sc26xx_type,
.release_port = sc26xx_release_port,
.request_port = sc26xx_request_port,
.config_port = sc26xx_config_port,
.verify_port = sc26xx_verify_port,
};
static struct uart_port *sc26xx_port;
#ifdef CONFIG_SERIAL_SC26XX_CONSOLE
static void sc26xx_console_putchar(struct uart_port *port, char c)
{
unsigned long flags;
int limit = 1000000;
spin_lock_irqsave(&port->lock, flags);
while (limit-- > 0) {
if (READ_SC_PORT(port, SR) & SR_TXRDY) {
WRITE_SC_PORT(port, THR, c);
break;
}
udelay(2);
}
spin_unlock_irqrestore(&port->lock, flags);
}
static void sc26xx_console_write(struct console *con, const char *s, unsigned n)
{
struct uart_port *port = sc26xx_port;
int i;
for (i = 0; i < n; i++) {
if (*s == '\n')
sc26xx_console_putchar(port, '\r');
sc26xx_console_putchar(port, *s++);
}
}
static int __init sc26xx_console_setup(struct console *con, char *options)
{
struct uart_port *port = sc26xx_port;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (port->type != PORT_SC26XX)
return -1;
printk(KERN_INFO "Console: ttySC%d (SC26XX)\n", con->index);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, con, baud, parity, bits, flow);
}
static struct uart_driver sc26xx_reg;
static struct console sc26xx_console = {
.name = "ttySC",
.write = sc26xx_console_write,
.device = uart_console_device,
.setup = sc26xx_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &sc26xx_reg,
};
#define SC26XX_CONSOLE &sc26xx_console
#else
#define SC26XX_CONSOLE NULL
#endif
static struct uart_driver sc26xx_reg = {
.owner = THIS_MODULE,
.driver_name = "SC26xx",
.dev_name = "ttySC",
.major = SC26XX_MAJOR,
.minor = SC26XX_MINOR_START,
.nr = SC26XX_NR,
.cons = SC26XX_CONSOLE,
};
static u8 sc26xx_flags2mask(unsigned int flags, unsigned int bitpos)
{
unsigned int bit = (flags >> bitpos) & 15;
return bit ? (1 << (bit - 1)) : 0;
}
static void __devinit sc26xx_init_masks(struct uart_sc26xx_port *up,
int line, unsigned int data)
{
up->dtr_mask[line] = sc26xx_flags2mask(data, 0);
up->rts_mask[line] = sc26xx_flags2mask(data, 4);
up->dsr_mask[line] = sc26xx_flags2mask(data, 8);
up->cts_mask[line] = sc26xx_flags2mask(data, 12);
up->dcd_mask[line] = sc26xx_flags2mask(data, 16);
up->ri_mask[line] = sc26xx_flags2mask(data, 20);
}
static int __devinit sc26xx_probe(struct platform_device *dev)
{
struct resource *res;
struct uart_sc26xx_port *up;
unsigned int *sc26xx_data = dev->dev.platform_data;
int err;
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
up = kzalloc(sizeof *up, GFP_KERNEL);
if (unlikely(!up))
return -ENOMEM;
up->port[0].line = 0;
up->port[0].ops = &sc26xx_ops;
up->port[0].type = PORT_SC26XX;
up->port[0].uartclk = (29491200 / 16); /* arbitrary */
up->port[0].mapbase = res->start;
up->port[0].membase = ioremap_nocache(up->port[0].mapbase, 0x40);
up->port[0].iotype = UPIO_MEM;
up->port[0].irq = platform_get_irq(dev, 0);
up->port[0].dev = &dev->dev;
sc26xx_init_masks(up, 0, sc26xx_data[0]);
sc26xx_port = &up->port[0];
up->port[1].line = 1;
up->port[1].ops = &sc26xx_ops;
up->port[1].type = PORT_SC26XX;
up->port[1].uartclk = (29491200 / 16); /* arbitrary */
up->port[1].mapbase = up->port[0].mapbase;
up->port[1].membase = up->port[0].membase;
up->port[1].iotype = UPIO_MEM;
up->port[1].irq = up->port[0].irq;
up->port[1].dev = &dev->dev;
sc26xx_init_masks(up, 1, sc26xx_data[1]);
err = uart_register_driver(&sc26xx_reg);
if (err)
goto out_free_port;
sc26xx_reg.tty_driver->name_base = sc26xx_reg.minor;
err = uart_add_one_port(&sc26xx_reg, &up->port[0]);
if (err)
goto out_unregister_driver;
err = uart_add_one_port(&sc26xx_reg, &up->port[1]);
if (err)
goto out_remove_port0;
err = request_irq(up->port[0].irq, sc26xx_interrupt, 0, "sc26xx", up);
if (err)
goto out_remove_ports;
dev_set_drvdata(&dev->dev, up);
return 0;
out_remove_ports:
uart_remove_one_port(&sc26xx_reg, &up->port[1]);
out_remove_port0:
uart_remove_one_port(&sc26xx_reg, &up->port[0]);
out_unregister_driver:
uart_unregister_driver(&sc26xx_reg);
out_free_port:
kfree(up);
sc26xx_port = NULL;
return err;
}
static int __exit sc26xx_driver_remove(struct platform_device *dev)
{
struct uart_sc26xx_port *up = dev_get_drvdata(&dev->dev);
free_irq(up->port[0].irq, up);
uart_remove_one_port(&sc26xx_reg, &up->port[0]);
uart_remove_one_port(&sc26xx_reg, &up->port[1]);
uart_unregister_driver(&sc26xx_reg);
kfree(up);
sc26xx_port = NULL;
dev_set_drvdata(&dev->dev, NULL);
return 0;
}
static struct platform_driver sc26xx_driver = {
.probe = sc26xx_probe,
.remove = __devexit_p(sc26xx_driver_remove),
.driver = {
.name = "SC26xx",
.owner = THIS_MODULE,
},
};
static int __init sc26xx_init(void)
{
return platform_driver_register(&sc26xx_driver);
}
static void __exit sc26xx_exit(void)
{
platform_driver_unregister(&sc26xx_driver);
}
module_init(sc26xx_init);
module_exit(sc26xx_exit);
MODULE_AUTHOR("Thomas Bogendörfer");
MODULE_DESCRIPTION("SC681/SC2692 serial driver");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:SC26xx");