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linux/drivers/tty/serial/samsung.c
Thomas Abraham 88bb4ea14c serial: samsung: Add unified interrupt handler for s3c64xx and later SoC's 
s3c64xx and later SoC's include the interrupt mask and pending registers
in the uart controller, unlike the s3c24xx SoC's which have these registers
in the interrupt controller. When the mask and pending registers are part
of the uart controller, a unified interrupt handler can handle the tx/rx
interrupt. With this, the static reservation of interrupt numbers for the
uart tx/rx/err interrupts in the linux irq space is not required and
simplifies adding device tree support.

Suggested-by: Grant Likely <grant.likely@secretlab.ca>
CC: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-23 10:48:31 -07:00

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/*
* Driver core for Samsung SoC onboard UARTs.
*
* Ben Dooks, Copyright (c) 2003-2008 Simtec Electronics
* http://armlinux.simtec.co.uk/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/* Hote on 2410 error handling
*
* The s3c2410 manual has a love/hate affair with the contents of the
* UERSTAT register in the UART blocks, and keeps marking some of the
* error bits as reserved. Having checked with the s3c2410x01,
* it copes with BREAKs properly, so I am happy to ignore the RESERVED
* feature from the latter versions of the manual.
*
* If it becomes aparrent that latter versions of the 2410 remove these
* bits, then action will have to be taken to differentiate the versions
* and change the policy on BREAK
*
* BJD, 04-Nov-2004
*/
#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/cpufreq.h>
#include <asm/irq.h>
#include <mach/hardware.h>
#include <mach/map.h>
#include <plat/regs-serial.h>
#include "samsung.h"
/* UART name and device definitions */
#define S3C24XX_SERIAL_NAME "ttySAC"
#define S3C24XX_SERIAL_MAJOR 204
#define S3C24XX_SERIAL_MINOR 64
/* macros to change one thing to another */
#define tx_enabled(port) ((port)->unused[0])
#define rx_enabled(port) ((port)->unused[1])
/* flag to ignore all characters coming in */
#define RXSTAT_DUMMY_READ (0x10000000)
static inline struct s3c24xx_uart_port *to_ourport(struct uart_port *port)
{
return container_of(port, struct s3c24xx_uart_port, port);
}
/* translate a port to the device name */
static inline const char *s3c24xx_serial_portname(struct uart_port *port)
{
return to_platform_device(port->dev)->name;
}
static int s3c24xx_serial_txempty_nofifo(struct uart_port *port)
{
return (rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE);
}
/*
* s3c64xx and later SoC's include the interrupt mask and status registers in
* the controller itself, unlike the s3c24xx SoC's which have these registers
* in the interrupt controller. Check if the port type is s3c64xx or higher.
*/
static int s3c24xx_serial_has_interrupt_mask(struct uart_port *port)
{
return to_ourport(port)->info->type == PORT_S3C6400;
}
static void s3c24xx_serial_rx_enable(struct uart_port *port)
{
unsigned long flags;
unsigned int ucon, ufcon;
int count = 10000;
spin_lock_irqsave(&port->lock, flags);
while (--count && !s3c24xx_serial_txempty_nofifo(port))
udelay(100);
ufcon = rd_regl(port, S3C2410_UFCON);
ufcon |= S3C2410_UFCON_RESETRX;
wr_regl(port, S3C2410_UFCON, ufcon);
ucon = rd_regl(port, S3C2410_UCON);
ucon |= S3C2410_UCON_RXIRQMODE;
wr_regl(port, S3C2410_UCON, ucon);
rx_enabled(port) = 1;
spin_unlock_irqrestore(&port->lock, flags);
}
static void s3c24xx_serial_rx_disable(struct uart_port *port)
{
unsigned long flags;
unsigned int ucon;
spin_lock_irqsave(&port->lock, flags);
ucon = rd_regl(port, S3C2410_UCON);
ucon &= ~S3C2410_UCON_RXIRQMODE;
wr_regl(port, S3C2410_UCON, ucon);
rx_enabled(port) = 0;
spin_unlock_irqrestore(&port->lock, flags);
}
static void s3c24xx_serial_stop_tx(struct uart_port *port)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
if (tx_enabled(port)) {
if (s3c24xx_serial_has_interrupt_mask(port))
__set_bit(S3C64XX_UINTM_TXD,
portaddrl(port, S3C64XX_UINTM));
else
disable_irq_nosync(ourport->tx_irq);
tx_enabled(port) = 0;
if (port->flags & UPF_CONS_FLOW)
s3c24xx_serial_rx_enable(port);
}
}
static void s3c24xx_serial_start_tx(struct uart_port *port)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
if (!tx_enabled(port)) {
if (port->flags & UPF_CONS_FLOW)
s3c24xx_serial_rx_disable(port);
if (s3c24xx_serial_has_interrupt_mask(port))
__clear_bit(S3C64XX_UINTM_TXD,
portaddrl(port, S3C64XX_UINTM));
else
enable_irq(ourport->tx_irq);
tx_enabled(port) = 1;
}
}
static void s3c24xx_serial_stop_rx(struct uart_port *port)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
if (rx_enabled(port)) {
dbg("s3c24xx_serial_stop_rx: port=%p\n", port);
if (s3c24xx_serial_has_interrupt_mask(port))
__set_bit(S3C64XX_UINTM_RXD,
portaddrl(port, S3C64XX_UINTM));
else
disable_irq_nosync(ourport->rx_irq);
rx_enabled(port) = 0;
}
}
static void s3c24xx_serial_enable_ms(struct uart_port *port)
{
}
static inline struct s3c24xx_uart_info *s3c24xx_port_to_info(struct uart_port *port)
{
return to_ourport(port)->info;
}
static inline struct s3c2410_uartcfg *s3c24xx_port_to_cfg(struct uart_port *port)
{
if (port->dev == NULL)
return NULL;
return (struct s3c2410_uartcfg *)port->dev->platform_data;
}
static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport,
unsigned long ufstat)
{
struct s3c24xx_uart_info *info = ourport->info;
if (ufstat & info->rx_fifofull)
return info->fifosize;
return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
}
/* ? - where has parity gone?? */
#define S3C2410_UERSTAT_PARITY (0x1000)
static irqreturn_t
s3c24xx_serial_rx_chars(int irq, void *dev_id)
{
struct s3c24xx_uart_port *ourport = dev_id;
struct uart_port *port = &ourport->port;
struct tty_struct *tty = port->state->port.tty;
unsigned int ufcon, ch, flag, ufstat, uerstat;
int max_count = 64;
while (max_count-- > 0) {
ufcon = rd_regl(port, S3C2410_UFCON);
ufstat = rd_regl(port, S3C2410_UFSTAT);
if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
break;
uerstat = rd_regl(port, S3C2410_UERSTAT);
ch = rd_regb(port, S3C2410_URXH);
if (port->flags & UPF_CONS_FLOW) {
int txe = s3c24xx_serial_txempty_nofifo(port);
if (rx_enabled(port)) {
if (!txe) {
rx_enabled(port) = 0;
continue;
}
} else {
if (txe) {
ufcon |= S3C2410_UFCON_RESETRX;
wr_regl(port, S3C2410_UFCON, ufcon);
rx_enabled(port) = 1;
goto out;
}
continue;
}
}
/* insert the character into the buffer */
flag = TTY_NORMAL;
port->icount.rx++;
if (unlikely(uerstat & S3C2410_UERSTAT_ANY)) {
dbg("rxerr: port ch=0x%02x, rxs=0x%08x\n",
ch, uerstat);
/* check for break */
if (uerstat & S3C2410_UERSTAT_BREAK) {
dbg("break!\n");
port->icount.brk++;
if (uart_handle_break(port))
goto ignore_char;
}
if (uerstat & S3C2410_UERSTAT_FRAME)
port->icount.frame++;
if (uerstat & S3C2410_UERSTAT_OVERRUN)
port->icount.overrun++;
uerstat &= port->read_status_mask;
if (uerstat & S3C2410_UERSTAT_BREAK)
flag = TTY_BREAK;
else if (uerstat & S3C2410_UERSTAT_PARITY)
flag = TTY_PARITY;
else if (uerstat & (S3C2410_UERSTAT_FRAME |
S3C2410_UERSTAT_OVERRUN))
flag = TTY_FRAME;
}
if (uart_handle_sysrq_char(port, ch))
goto ignore_char;
uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN,
ch, flag);
ignore_char:
continue;
}
tty_flip_buffer_push(tty);
out:
return IRQ_HANDLED;
}
static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
{
struct s3c24xx_uart_port *ourport = id;
struct uart_port *port = &ourport->port;
struct circ_buf *xmit = &port->state->xmit;
int count = 256;
if (port->x_char) {
wr_regb(port, S3C2410_UTXH, port->x_char);
port->icount.tx++;
port->x_char = 0;
goto out;
}
/* if there isn't anything more to transmit, or the uart is now
* stopped, disable the uart and exit
*/
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
s3c24xx_serial_stop_tx(port);
goto out;
}
/* try and drain the buffer... */
while (!uart_circ_empty(xmit) && count-- > 0) {
if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
break;
wr_regb(port, S3C2410_UTXH, 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))
s3c24xx_serial_stop_tx(port);
out:
return IRQ_HANDLED;
}
/* interrupt handler for s3c64xx and later SoC's.*/
static irqreturn_t s3c64xx_serial_handle_irq(int irq, void *id)
{
struct s3c24xx_uart_port *ourport = id;
struct uart_port *port = &ourport->port;
unsigned int pend = rd_regl(port, S3C64XX_UINTP);
unsigned long flags;
irqreturn_t ret = IRQ_HANDLED;
spin_lock_irqsave(&port->lock, flags);
if (pend & S3C64XX_UINTM_RXD_MSK) {
ret = s3c24xx_serial_rx_chars(irq, id);
wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_RXD_MSK);
}
if (pend & S3C64XX_UINTM_TXD_MSK) {
ret = s3c24xx_serial_tx_chars(irq, id);
wr_regl(port, S3C64XX_UINTP, S3C64XX_UINTM_TXD_MSK);
}
spin_unlock_irqrestore(&port->lock, flags);
return ret;
}
static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
{
struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
unsigned long ufstat = rd_regl(port, S3C2410_UFSTAT);
unsigned long ufcon = rd_regl(port, S3C2410_UFCON);
if (ufcon & S3C2410_UFCON_FIFOMODE) {
if ((ufstat & info->tx_fifomask) != 0 ||
(ufstat & info->tx_fifofull))
return 0;
return 1;
}
return s3c24xx_serial_txempty_nofifo(port);
}
/* no modem control lines */
static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
{
unsigned int umstat = rd_regb(port, S3C2410_UMSTAT);
if (umstat & S3C2410_UMSTAT_CTS)
return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
else
return TIOCM_CAR | TIOCM_DSR;
}
static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
/* todo - possibly remove AFC and do manual CTS */
}
static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
{
unsigned long flags;
unsigned int ucon;
spin_lock_irqsave(&port->lock, flags);
ucon = rd_regl(port, S3C2410_UCON);
if (break_state)
ucon |= S3C2410_UCON_SBREAK;
else
ucon &= ~S3C2410_UCON_SBREAK;
wr_regl(port, S3C2410_UCON, ucon);
spin_unlock_irqrestore(&port->lock, flags);
}
static void s3c24xx_serial_shutdown(struct uart_port *port)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
if (ourport->tx_claimed) {
if (!s3c24xx_serial_has_interrupt_mask(port))
free_irq(ourport->tx_irq, ourport);
tx_enabled(port) = 0;
ourport->tx_claimed = 0;
}
if (ourport->rx_claimed) {
if (!s3c24xx_serial_has_interrupt_mask(port))
free_irq(ourport->rx_irq, ourport);
ourport->rx_claimed = 0;
rx_enabled(port) = 0;
}
/* Clear pending interrupts and mask all interrupts */
if (s3c24xx_serial_has_interrupt_mask(port)) {
wr_regl(port, S3C64XX_UINTP, 0xf);
wr_regl(port, S3C64XX_UINTM, 0xf);
}
}
static int s3c24xx_serial_startup(struct uart_port *port)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
int ret;
dbg("s3c24xx_serial_startup: port=%p (%08lx,%p)\n",
port->mapbase, port->membase);
rx_enabled(port) = 1;
ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_chars, 0,
s3c24xx_serial_portname(port), ourport);
if (ret != 0) {
printk(KERN_ERR "cannot get irq %d\n", ourport->rx_irq);
return ret;
}
ourport->rx_claimed = 1;
dbg("requesting tx irq...\n");
tx_enabled(port) = 1;
ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_chars, 0,
s3c24xx_serial_portname(port), ourport);
if (ret) {
printk(KERN_ERR "cannot get irq %d\n", ourport->tx_irq);
goto err;
}
ourport->tx_claimed = 1;
dbg("s3c24xx_serial_startup ok\n");
/* the port reset code should have done the correct
* register setup for the port controls */
return ret;
err:
s3c24xx_serial_shutdown(port);
return ret;
}
static int s3c64xx_serial_startup(struct uart_port *port)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
int ret;
dbg("s3c64xx_serial_startup: port=%p (%08lx,%p)\n",
port->mapbase, port->membase);
ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
s3c24xx_serial_portname(port), ourport);
if (ret) {
printk(KERN_ERR "cannot get irq %d\n", port->irq);
return ret;
}
/* For compatibility with s3c24xx Soc's */
rx_enabled(port) = 1;
ourport->rx_claimed = 1;
tx_enabled(port) = 0;
ourport->tx_claimed = 1;
/* Enable Rx Interrupt */
__clear_bit(S3C64XX_UINTM_RXD, portaddrl(port, S3C64XX_UINTM));
dbg("s3c64xx_serial_startup ok\n");
return ret;
}
/* power power management control */
static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
unsigned int old)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
ourport->pm_level = level;
switch (level) {
case 3:
if (!IS_ERR(ourport->baudclk) && ourport->baudclk != NULL)
clk_disable(ourport->baudclk);
clk_disable(ourport->clk);
break;
case 0:
clk_enable(ourport->clk);
if (!IS_ERR(ourport->baudclk) && ourport->baudclk != NULL)
clk_enable(ourport->baudclk);
break;
default:
printk(KERN_ERR "s3c24xx_serial: unknown pm %d\n", level);
}
}
/* baud rate calculation
*
* The UARTs on the S3C2410/S3C2440 can take their clocks from a number
* of different sources, including the peripheral clock ("pclk") and an
* external clock ("uclk"). The S3C2440 also adds the core clock ("fclk")
* with a programmable extra divisor.
*
* The following code goes through the clock sources, and calculates the
* baud clocks (and the resultant actual baud rates) and then tries to
* pick the closest one and select that.
*
*/
#define MAX_CLKS (8)
static struct s3c24xx_uart_clksrc tmp_clksrc = {
.name = "pclk",
.min_baud = 0,
.max_baud = 0,
.divisor = 1,
};
static inline int
s3c24xx_serial_getsource(struct uart_port *port, struct s3c24xx_uart_clksrc *c)
{
struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
return (info->get_clksrc)(port, c);
}
static inline int
s3c24xx_serial_setsource(struct uart_port *port, struct s3c24xx_uart_clksrc *c)
{
struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
return (info->set_clksrc)(port, c);
}
struct baud_calc {
struct s3c24xx_uart_clksrc *clksrc;
unsigned int calc;
unsigned int divslot;
unsigned int quot;
struct clk *src;
};
static int s3c24xx_serial_calcbaud(struct baud_calc *calc,
struct uart_port *port,
struct s3c24xx_uart_clksrc *clksrc,
unsigned int baud)
{
struct s3c24xx_uart_port *ourport = to_ourport(port);
unsigned long rate;
calc->src = clk_get(port->dev, clksrc->name);
if (calc->src == NULL || IS_ERR(calc->src))
return 0;
rate = clk_get_rate(calc->src);
rate /= clksrc->divisor;
calc->clksrc = clksrc;
if (ourport->info->has_divslot) {
unsigned long div = rate / baud;
/* The UDIVSLOT register on the newer UARTs allows us to
* get a divisor adjustment of 1/16th on the baud clock.
*
* We don't keep the UDIVSLOT value (the 16ths we calculated
* by not multiplying the baud by 16) as it is easy enough
* to recalculate.
*/
calc->quot = div / 16;
calc->calc = rate / div;
} else {
calc->quot = (rate + (8 * baud)) / (16 * baud);
calc->calc = (rate / (calc->quot * 16));
}
calc->quot--;
return 1;
}
static unsigned int s3c24xx_serial_getclk(struct uart_port *port,
struct s3c24xx_uart_clksrc **clksrc,
struct clk **clk,
unsigned int baud)
{
struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
struct s3c24xx_uart_clksrc *clkp;
struct baud_calc res[MAX_CLKS];
struct baud_calc *resptr, *best, *sptr;
int i;
clkp = cfg->clocks;
best = NULL;
if (cfg->clocks_size < 2) {
if (cfg->clocks_size == 0)
clkp = &tmp_clksrc;
/* check to see if we're sourcing fclk, and if so we're
* going to have to update the clock source
*/
if (strcmp(clkp->name, "fclk") == 0) {
struct s3c24xx_uart_clksrc src;
s3c24xx_serial_getsource(port, &src);
/* check that the port already using fclk, and if
* not, then re-select fclk
*/
if (strcmp(src.name, clkp->name) == 0) {
s3c24xx_serial_setsource(port, clkp);
s3c24xx_serial_getsource(port, &src);
}
clkp->divisor = src.divisor;
}
s3c24xx_serial_calcbaud(res, port, clkp, baud);
best = res;
resptr = best + 1;
} else {
resptr = res;
for (i = 0; i < cfg->clocks_size; i++, clkp++) {
if (s3c24xx_serial_calcbaud(resptr, port, clkp, baud))
resptr++;
}
}
/* ok, we now need to select the best clock we found */
if (!best) {
unsigned int deviation = (1<<30)|((1<<30)-1);
int calc_deviation;
for (sptr = res; sptr < resptr; sptr++) {
calc_deviation = baud - sptr->calc;
if (calc_deviation < 0)
calc_deviation = -calc_deviation;
if (calc_deviation < deviation) {
best = sptr;
deviation = calc_deviation;
}
}
}
/* store results to pass back */
*clksrc = best->clksrc;
*clk = best->src;
return best->quot;
}
/* udivslot_table[]
*
* This table takes the fractional value of the baud divisor and gives
* the recommended setting for the UDIVSLOT register.
*/
static u16 udivslot_table[16] = {
[0] = 0x0000,
[1] = 0x0080,
[2] = 0x0808,
[3] = 0x0888,
[4] = 0x2222,
[5] = 0x4924,
[6] = 0x4A52,
[7] = 0x54AA,
[8] = 0x5555,
[9] = 0xD555,
[10] = 0xD5D5,
[11] = 0xDDD5,
[12] = 0xDDDD,
[13] = 0xDFDD,
[14] = 0xDFDF,
[15] = 0xFFDF,
};
static void s3c24xx_serial_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
struct s3c24xx_uart_port *ourport = to_ourport(port);
struct s3c24xx_uart_clksrc *clksrc = NULL;
struct clk *clk = NULL;
unsigned long flags;
unsigned int baud, quot;
unsigned int ulcon;
unsigned int umcon;
unsigned int udivslot = 0;
/*
* We don't support modem control lines.
*/
termios->c_cflag &= ~(HUPCL | CMSPAR);
termios->c_cflag |= CLOCAL;
/*
* Ask the core to calculate the divisor for us.
*/
baud = uart_get_baud_rate(port, termios, old, 0, 115200*8);
if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
quot = port->custom_divisor;
else
quot = s3c24xx_serial_getclk(port, &clksrc, &clk, baud);
/* check to see if we need to change clock source */
if (ourport->clksrc != clksrc || ourport->baudclk != clk) {
dbg("selecting clock %p\n", clk);
s3c24xx_serial_setsource(port, clksrc);
if (ourport->baudclk != NULL && !IS_ERR(ourport->baudclk)) {
clk_disable(ourport->baudclk);
ourport->baudclk = NULL;
}
clk_enable(clk);
ourport->clksrc = clksrc;
ourport->baudclk = clk;
ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0;
}
if (ourport->info->has_divslot) {
unsigned int div = ourport->baudclk_rate / baud;
if (cfg->has_fracval) {
udivslot = (div & 15);
dbg("fracval = %04x\n", udivslot);
} else {
udivslot = udivslot_table[div & 15];
dbg("udivslot = %04x (div %d)\n", udivslot, div & 15);
}
}
switch (termios->c_cflag & CSIZE) {
case CS5:
dbg("config: 5bits/char\n");
ulcon = S3C2410_LCON_CS5;
break;
case CS6:
dbg("config: 6bits/char\n");
ulcon = S3C2410_LCON_CS6;
break;
case CS7:
dbg("config: 7bits/char\n");
ulcon = S3C2410_LCON_CS7;
break;
case CS8:
default:
dbg("config: 8bits/char\n");
ulcon = S3C2410_LCON_CS8;
break;
}
/* preserve original lcon IR settings */
ulcon |= (cfg->ulcon & S3C2410_LCON_IRM);
if (termios->c_cflag & CSTOPB)
ulcon |= S3C2410_LCON_STOPB;
umcon = (termios->c_cflag & CRTSCTS) ? S3C2410_UMCOM_AFC : 0;
if (termios->c_cflag & PARENB) {
if (termios->c_cflag & PARODD)
ulcon |= S3C2410_LCON_PODD;
else
ulcon |= S3C2410_LCON_PEVEN;
} else {
ulcon |= S3C2410_LCON_PNONE;
}
spin_lock_irqsave(&port->lock, flags);
dbg("setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
ulcon, quot, udivslot);
wr_regl(port, S3C2410_ULCON, ulcon);
wr_regl(port, S3C2410_UBRDIV, quot);
wr_regl(port, S3C2410_UMCON, umcon);
if (ourport->info->has_divslot)
wr_regl(port, S3C2443_DIVSLOT, udivslot);
dbg("uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
rd_regl(port, S3C2410_ULCON),
rd_regl(port, S3C2410_UCON),
rd_regl(port, S3C2410_UFCON));
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
/*
* Which character status flags are we interested in?
*/
port->read_status_mask = S3C2410_UERSTAT_OVERRUN;
if (termios->c_iflag & INPCK)
port->read_status_mask |= S3C2410_UERSTAT_FRAME | S3C2410_UERSTAT_PARITY;
/*
* Which character status flags should we ignore?
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= S3C2410_UERSTAT_OVERRUN;
if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
port->ignore_status_mask |= S3C2410_UERSTAT_FRAME;
/*
* Ignore all characters if CREAD is not set.
*/
if ((termios->c_cflag & CREAD) == 0)
port->ignore_status_mask |= RXSTAT_DUMMY_READ;
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *s3c24xx_serial_type(struct uart_port *port)
{
switch (port->type) {
case PORT_S3C2410:
return "S3C2410";
case PORT_S3C2440:
return "S3C2440";
case PORT_S3C2412:
return "S3C2412";
case PORT_S3C6400:
return "S3C6400/10";
default:
return NULL;
}
}
#define MAP_SIZE (0x100)
static void s3c24xx_serial_release_port(struct uart_port *port)
{
release_mem_region(port->mapbase, MAP_SIZE);
}
static int s3c24xx_serial_request_port(struct uart_port *port)
{
const char *name = s3c24xx_serial_portname(port);
return request_mem_region(port->mapbase, MAP_SIZE, name) ? 0 : -EBUSY;
}
static void s3c24xx_serial_config_port(struct uart_port *port, int flags)
{
struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
if (flags & UART_CONFIG_TYPE &&
s3c24xx_serial_request_port(port) == 0)
port->type = info->type;
}
/*
* verify the new serial_struct (for TIOCSSERIAL).
*/
static int
s3c24xx_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
{
struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
if (ser->type != PORT_UNKNOWN && ser->type != info->type)
return -EINVAL;
return 0;
}
#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
static struct console s3c24xx_serial_console;
#define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
#else
#define S3C24XX_SERIAL_CONSOLE NULL
#endif
static struct uart_ops s3c24xx_serial_ops = {
.pm = s3c24xx_serial_pm,
.tx_empty = s3c24xx_serial_tx_empty,
.get_mctrl = s3c24xx_serial_get_mctrl,
.set_mctrl = s3c24xx_serial_set_mctrl,
.stop_tx = s3c24xx_serial_stop_tx,
.start_tx = s3c24xx_serial_start_tx,
.stop_rx = s3c24xx_serial_stop_rx,
.enable_ms = s3c24xx_serial_enable_ms,
.break_ctl = s3c24xx_serial_break_ctl,
.startup = s3c24xx_serial_startup,
.shutdown = s3c24xx_serial_shutdown,
.set_termios = s3c24xx_serial_set_termios,
.type = s3c24xx_serial_type,
.release_port = s3c24xx_serial_release_port,
.request_port = s3c24xx_serial_request_port,
.config_port = s3c24xx_serial_config_port,
.verify_port = s3c24xx_serial_verify_port,
};
static struct uart_driver s3c24xx_uart_drv = {
.owner = THIS_MODULE,
.driver_name = "s3c2410_serial",
.nr = CONFIG_SERIAL_SAMSUNG_UARTS,
.cons = S3C24XX_SERIAL_CONSOLE,
.dev_name = S3C24XX_SERIAL_NAME,
.major = S3C24XX_SERIAL_MAJOR,
.minor = S3C24XX_SERIAL_MINOR,
};
static struct s3c24xx_uart_port s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS] = {
[0] = {
.port = {
.lock = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[0].port.lock),
.iotype = UPIO_MEM,
.uartclk = 0,
.fifosize = 16,
.ops = &s3c24xx_serial_ops,
.flags = UPF_BOOT_AUTOCONF,
.line = 0,
}
},
[1] = {
.port = {
.lock = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[1].port.lock),
.iotype = UPIO_MEM,
.uartclk = 0,
.fifosize = 16,
.ops = &s3c24xx_serial_ops,
.flags = UPF_BOOT_AUTOCONF,
.line = 1,
}
},
#if CONFIG_SERIAL_SAMSUNG_UARTS > 2
[2] = {
.port = {
.lock = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[2].port.lock),
.iotype = UPIO_MEM,
.uartclk = 0,
.fifosize = 16,
.ops = &s3c24xx_serial_ops,
.flags = UPF_BOOT_AUTOCONF,
.line = 2,
}
},
#endif
#if CONFIG_SERIAL_SAMSUNG_UARTS > 3
[3] = {
.port = {
.lock = __SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[3].port.lock),
.iotype = UPIO_MEM,
.uartclk = 0,
.fifosize = 16,
.ops = &s3c24xx_serial_ops,
.flags = UPF_BOOT_AUTOCONF,
.line = 3,
}
}
#endif
};
/* s3c24xx_serial_resetport
*
* wrapper to call the specific reset for this port (reset the fifos
* and the settings)
*/
static inline int s3c24xx_serial_resetport(struct uart_port *port,
struct s3c2410_uartcfg *cfg)
{
struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
return (info->reset_port)(port, cfg);
}
#ifdef CONFIG_CPU_FREQ
static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
unsigned long val, void *data)
{
struct s3c24xx_uart_port *port;
struct uart_port *uport;
port = container_of(nb, struct s3c24xx_uart_port, freq_transition);
uport = &port->port;
/* check to see if port is enabled */
if (port->pm_level != 0)
return 0;
/* try and work out if the baudrate is changing, we can detect
* a change in rate, but we do not have support for detecting
* a disturbance in the clock-rate over the change.
*/
if (IS_ERR(port->clk))
goto exit;
if (port->baudclk_rate == clk_get_rate(port->clk))
goto exit;
if (val == CPUFREQ_PRECHANGE) {
/* we should really shut the port down whilst the
* frequency change is in progress. */
} else if (val == CPUFREQ_POSTCHANGE) {
struct ktermios *termios;
struct tty_struct *tty;
if (uport->state == NULL)
goto exit;
tty = uport->state->port.tty;
if (tty == NULL)
goto exit;
termios = tty->termios;
if (termios == NULL) {
printk(KERN_WARNING "%s: no termios?\n", __func__);
goto exit;
}
s3c24xx_serial_set_termios(uport, termios, NULL);
}
exit:
return 0;
}
static inline int s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
{
port->freq_transition.notifier_call = s3c24xx_serial_cpufreq_transition;
return cpufreq_register_notifier(&port->freq_transition,
CPUFREQ_TRANSITION_NOTIFIER);
}
static inline void s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
{
cpufreq_unregister_notifier(&port->freq_transition,
CPUFREQ_TRANSITION_NOTIFIER);
}
#else
static inline int s3c24xx_serial_cpufreq_register(struct s3c24xx_uart_port *port)
{
return 0;
}
static inline void s3c24xx_serial_cpufreq_deregister(struct s3c24xx_uart_port *port)
{
}
#endif
/* s3c24xx_serial_init_port
*
* initialise a single serial port from the platform device given
*/
static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
struct s3c24xx_uart_info *info,
struct platform_device *platdev)
{
struct uart_port *port = &ourport->port;
struct s3c2410_uartcfg *cfg;
struct resource *res;
int ret;
dbg("s3c24xx_serial_init_port: port=%p, platdev=%p\n", port, platdev);
if (platdev == NULL)
return -ENODEV;
cfg = s3c24xx_dev_to_cfg(&platdev->dev);
if (port->mapbase != 0)
return 0;
if (cfg->hwport > CONFIG_SERIAL_SAMSUNG_UARTS) {
printk(KERN_ERR "%s: port %d bigger than %d\n", __func__,
cfg->hwport, CONFIG_SERIAL_SAMSUNG_UARTS);
return -ERANGE;
}
/* setup info for port */
port->dev = &platdev->dev;
ourport->info = info;
/* Startup sequence is different for s3c64xx and higher SoC's */
if (s3c24xx_serial_has_interrupt_mask(port))
s3c24xx_serial_ops.startup = s3c64xx_serial_startup;
/* copy the info in from provided structure */
ourport->port.fifosize = info->fifosize;
dbg("s3c24xx_serial_init_port: %p (hw %d)...\n", port, cfg->hwport);
port->uartclk = 1;
if (cfg->uart_flags & UPF_CONS_FLOW) {
dbg("s3c24xx_serial_init_port: enabling flow control\n");
port->flags |= UPF_CONS_FLOW;
}
/* sort our the physical and virtual addresses for each UART */
res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
if (res == NULL) {
printk(KERN_ERR "failed to find memory resource for uart\n");
return -EINVAL;
}
dbg("resource %p (%lx..%lx)\n", res, res->start, res->end);
port->mapbase = res->start;
port->membase = S3C_VA_UART + (res->start & 0xfffff);
ret = platform_get_irq(platdev, 0);
if (ret < 0)
port->irq = 0;
else {
port->irq = ret;
ourport->rx_irq = ret;
ourport->tx_irq = ret + 1;
}
ret = platform_get_irq(platdev, 1);
if (ret > 0)
ourport->tx_irq = ret;
ourport->clk = clk_get(&platdev->dev, "uart");
/* Keep all interrupts masked and cleared */
if (s3c24xx_serial_has_interrupt_mask(port)) {
wr_regl(port, S3C64XX_UINTM, 0xf);
wr_regl(port, S3C64XX_UINTP, 0xf);
wr_regl(port, S3C64XX_UINTSP, 0xf);
}
dbg("port: map=%08x, mem=%08x, irq=%d (%d,%d), clock=%ld\n",
port->mapbase, port->membase, port->irq,
ourport->rx_irq, ourport->tx_irq, port->uartclk);
/* reset the fifos (and setup the uart) */
s3c24xx_serial_resetport(port, cfg);
return 0;
}
static ssize_t s3c24xx_serial_show_clksrc(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct uart_port *port = s3c24xx_dev_to_port(dev);
struct s3c24xx_uart_port *ourport = to_ourport(port);
return snprintf(buf, PAGE_SIZE, "* %s\n", ourport->clksrc->name);
}
static DEVICE_ATTR(clock_source, S_IRUGO, s3c24xx_serial_show_clksrc, NULL);
/* Device driver serial port probe */
static int probe_index;
int s3c24xx_serial_probe(struct platform_device *dev,
struct s3c24xx_uart_info *info)
{
struct s3c24xx_uart_port *ourport;
int ret;
dbg("s3c24xx_serial_probe(%p, %p) %d\n", dev, info, probe_index);
ourport = &s3c24xx_serial_ports[probe_index];
probe_index++;
dbg("%s: initialising port %p...\n", __func__, ourport);
ret = s3c24xx_serial_init_port(ourport, info, dev);
if (ret < 0)
goto probe_err;
dbg("%s: adding port\n", __func__);
uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
platform_set_drvdata(dev, &ourport->port);
ret = device_create_file(&dev->dev, &dev_attr_clock_source);
if (ret < 0)
printk(KERN_ERR "%s: failed to add clksrc attr.\n", __func__);
ret = s3c24xx_serial_cpufreq_register(ourport);
if (ret < 0)
dev_err(&dev->dev, "failed to add cpufreq notifier\n");
return 0;
probe_err:
return ret;
}
EXPORT_SYMBOL_GPL(s3c24xx_serial_probe);
int __devexit s3c24xx_serial_remove(struct platform_device *dev)
{
struct uart_port *port = s3c24xx_dev_to_port(&dev->dev);
if (port) {
s3c24xx_serial_cpufreq_deregister(to_ourport(port));
device_remove_file(&dev->dev, &dev_attr_clock_source);
uart_remove_one_port(&s3c24xx_uart_drv, port);
}
return 0;
}
EXPORT_SYMBOL_GPL(s3c24xx_serial_remove);
/* UART power management code */
#ifdef CONFIG_PM_SLEEP
static int s3c24xx_serial_suspend(struct device *dev)
{
struct uart_port *port = s3c24xx_dev_to_port(dev);
if (port)
uart_suspend_port(&s3c24xx_uart_drv, port);
return 0;
}
static int s3c24xx_serial_resume(struct device *dev)
{
struct uart_port *port = s3c24xx_dev_to_port(dev);
struct s3c24xx_uart_port *ourport = to_ourport(port);
if (port) {
clk_enable(ourport->clk);
s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
clk_disable(ourport->clk);
uart_resume_port(&s3c24xx_uart_drv, port);
}
return 0;
}
static const struct dev_pm_ops s3c24xx_serial_pm_ops = {
.suspend = s3c24xx_serial_suspend,
.resume = s3c24xx_serial_resume,
};
#else /* !CONFIG_PM_SLEEP */
#define s3c24xx_serial_pm_ops NULL
#endif /* CONFIG_PM_SLEEP */
int s3c24xx_serial_init(struct platform_driver *drv,
struct s3c24xx_uart_info *info)
{
dbg("s3c24xx_serial_init(%p,%p)\n", drv, info);
drv->driver.pm = &s3c24xx_serial_pm_ops;
return platform_driver_register(drv);
}
EXPORT_SYMBOL_GPL(s3c24xx_serial_init);
/* module initialisation code */
static int __init s3c24xx_serial_modinit(void)
{
int ret;
ret = uart_register_driver(&s3c24xx_uart_drv);
if (ret < 0) {
printk(KERN_ERR "failed to register UART driver\n");
return -1;
}
return 0;
}
static void __exit s3c24xx_serial_modexit(void)
{
uart_unregister_driver(&s3c24xx_uart_drv);
}
module_init(s3c24xx_serial_modinit);
module_exit(s3c24xx_serial_modexit);
/* Console code */
#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
static struct uart_port *cons_uart;
static int
s3c24xx_serial_console_txrdy(struct uart_port *port, unsigned int ufcon)
{
struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port);
unsigned long ufstat, utrstat;
if (ufcon & S3C2410_UFCON_FIFOMODE) {
/* fifo mode - check amount of data in fifo registers... */
ufstat = rd_regl(port, S3C2410_UFSTAT);
return (ufstat & info->tx_fifofull) ? 0 : 1;
}
/* in non-fifo mode, we go and use the tx buffer empty */
utrstat = rd_regl(port, S3C2410_UTRSTAT);
return (utrstat & S3C2410_UTRSTAT_TXE) ? 1 : 0;
}
static void
s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
{
unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);
while (!s3c24xx_serial_console_txrdy(port, ufcon))
barrier();
wr_regb(cons_uart, S3C2410_UTXH, ch);
}
static void
s3c24xx_serial_console_write(struct console *co, const char *s,
unsigned int count)
{
uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
}
static void __init
s3c24xx_serial_get_options(struct uart_port *port, int *baud,
int *parity, int *bits)
{
struct s3c24xx_uart_clksrc clksrc;
struct clk *clk;
unsigned int ulcon;
unsigned int ucon;
unsigned int ubrdiv;
unsigned long rate;
ulcon = rd_regl(port, S3C2410_ULCON);
ucon = rd_regl(port, S3C2410_UCON);
ubrdiv = rd_regl(port, S3C2410_UBRDIV);
dbg("s3c24xx_serial_get_options: port=%p\n"
"registers: ulcon=%08x, ucon=%08x, ubdriv=%08x\n",
port, ulcon, ucon, ubrdiv);
if ((ucon & 0xf) != 0) {
/* consider the serial port configured if the tx/rx mode set */
switch (ulcon & S3C2410_LCON_CSMASK) {
case S3C2410_LCON_CS5:
*bits = 5;
break;
case S3C2410_LCON_CS6:
*bits = 6;
break;
case S3C2410_LCON_CS7:
*bits = 7;
break;
default:
case S3C2410_LCON_CS8:
*bits = 8;
break;
}
switch (ulcon & S3C2410_LCON_PMASK) {
case S3C2410_LCON_PEVEN:
*parity = 'e';
break;
case S3C2410_LCON_PODD:
*parity = 'o';
break;
case S3C2410_LCON_PNONE:
default:
*parity = 'n';
}
/* now calculate the baud rate */
s3c24xx_serial_getsource(port, &clksrc);
clk = clk_get(port->dev, clksrc.name);
if (!IS_ERR(clk) && clk != NULL)
rate = clk_get_rate(clk) / clksrc.divisor;
else
rate = 1;
*baud = rate / (16 * (ubrdiv + 1));
dbg("calculated baud %d\n", *baud);
}
}
/* s3c24xx_serial_init_ports
*
* initialise the serial ports from the machine provided initialisation
* data.
*/
static int s3c24xx_serial_init_ports(struct s3c24xx_uart_info **info)
{
struct s3c24xx_uart_port *ptr = s3c24xx_serial_ports;
struct platform_device **platdev_ptr;
int i;
dbg("s3c24xx_serial_init_ports: initialising ports...\n");
platdev_ptr = s3c24xx_uart_devs;
for (i = 0; i < CONFIG_SERIAL_SAMSUNG_UARTS; i++, ptr++, platdev_ptr++) {
s3c24xx_serial_init_port(ptr, info[i], *platdev_ptr);
}
return 0;
}
static int __init
s3c24xx_serial_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
dbg("s3c24xx_serial_console_setup: co=%p (%d), %s\n",
co, co->index, options);
/* is this a valid port */
if (co->index == -1 || co->index >= CONFIG_SERIAL_SAMSUNG_UARTS)
co->index = 0;
port = &s3c24xx_serial_ports[co->index].port;
/* is the port configured? */
if (port->mapbase == 0x0)
return -ENODEV;
cons_uart = port;
dbg("s3c24xx_serial_console_setup: port=%p (%d)\n", port, co->index);
/*
* Check whether an invalid uart number has been specified, and
* if so, search for the first available port that does have
* console support.
*/
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
s3c24xx_serial_get_options(port, &baud, &parity, &bits);
dbg("s3c24xx_serial_console_setup: baud %d\n", baud);
return uart_set_options(port, co, baud, parity, bits, flow);
}
/* s3c24xx_serial_initconsole
*
* initialise the console from one of the uart drivers
*/
static struct console s3c24xx_serial_console = {
.name = S3C24XX_SERIAL_NAME,
.device = uart_console_device,
.flags = CON_PRINTBUFFER,
.index = -1,
.write = s3c24xx_serial_console_write,
.setup = s3c24xx_serial_console_setup,
.data = &s3c24xx_uart_drv,
};
int s3c24xx_serial_initconsole(struct platform_driver *drv,
struct s3c24xx_uart_info **info)
{
struct platform_device *dev = s3c24xx_uart_devs[0];
dbg("s3c24xx_serial_initconsole\n");
/* select driver based on the cpu */
if (dev == NULL) {
printk(KERN_ERR "s3c24xx: no devices for console init\n");
return 0;
}
if (strcmp(dev->name, drv->driver.name) != 0)
return 0;
s3c24xx_serial_console.data = &s3c24xx_uart_drv;
s3c24xx_serial_init_ports(info);
register_console(&s3c24xx_serial_console);
return 0;
}
#endif /* CONFIG_SERIAL_SAMSUNG_CONSOLE */
MODULE_DESCRIPTION("Samsung SoC Serial port driver");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_LICENSE("GPL v2");
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