/* linux/drivers/serial/s3c2440.c
*
* Driver for Samsung S3C2440 and S3C2442 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.
*/
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <asm/irq.h>
#include <mach/hardware.h>
#include <plat/regs-serial.h>
#include <mach/regs-gpio.h>
#include "samsung.h"
static int s3c2440_serial_setsource(struct uart_port *port,
struct s3c24xx_uart_clksrc *clk)
{
unsigned long ucon = rd_regl(port, S3C2410_UCON);
/* todo - proper fclk<>nonfclk switch. */
ucon &= ~S3C2440_UCON_CLKMASK;
if (strcmp(clk->name, "uclk") == 0)
ucon |= S3C2440_UCON_UCLK;
else if (strcmp(clk->name, "pclk") == 0)
ucon |= S3C2440_UCON_PCLK;
else if (strcmp(clk->name, "fclk") == 0)
ucon |= S3C2440_UCON_FCLK;
else {
printk(KERN_ERR "unknown clock source %s\n", clk->name);
return -EINVAL;
}
wr_regl(port, S3C2410_UCON, ucon);
return 0;
}
static int s3c2440_serial_getsource(struct uart_port *port,
struct s3c24xx_uart_clksrc *clk)
{
unsigned long ucon = rd_regl(port, S3C2410_UCON);
unsigned long ucon0, ucon1, ucon2;
switch (ucon & S3C2440_UCON_CLKMASK) {
case S3C2440_UCON_UCLK:
clk->divisor = 1;
clk->name = "uclk";
break;
case S3C2440_UCON_PCLK:
case S3C2440_UCON_PCLK2:
clk->divisor = 1;
clk->name = "pclk";
break;
case S3C2440_UCON_FCLK:
/* the fun of calculating the uart divisors on
* the s3c2440 */
ucon0 = __raw_readl(S3C24XX_VA_UART0 + S3C2410_UCON);
ucon1 = __raw_readl(S3C24XX_VA_UART1 + S3C2410_UCON);
ucon2 = __raw_readl(S3C24XX_VA_UART2 + S3C2410_UCON);
printk("ucons: %08lx, %08lx, %08lx\n", ucon0, ucon1, ucon2);
ucon0 &= S3C2440_UCON0_DIVMASK;
ucon1 &= S3C2440_UCON1_DIVMASK;
ucon2 &= S3C2440_UCON2_DIVMASK;
if (ucon0 != 0) {
clk->divisor = ucon0 >> S3C2440_UCON_DIVSHIFT;
clk->divisor += 6;
} else if (ucon1 != 0) {
clk->divisor = ucon1 >> S3C2440_UCON_DIVSHIFT;
clk->divisor += 21;
} else if (ucon2 != 0) {
clk->divisor = ucon2 >> S3C2440_UCON_DIVSHIFT;
clk->divisor += 36;
} else {
/* manual calims 44, seems to be 9 */
clk->divisor = 9;
}
clk->name = "fclk";
break;
}
return 0;
}
static int s3c2440_serial_resetport(struct uart_port *port,
struct s3c2410_uartcfg *cfg)
{
unsigned long ucon = rd_regl(port, S3C2410_UCON);
dbg("s3c2440_serial_resetport: port=%p (%08lx), cfg=%p\n",
port, port->mapbase, cfg);
/* ensure we don't change the clock settings... */
ucon &= (S3C2440_UCON0_DIVMASK | (3<<10));
wr_regl(port, S3C2410_UCON, ucon | cfg->ucon);
wr_regl(port, S3C2410_ULCON, cfg->ulcon);
/* reset both fifos */
wr_regl(port, S3C2410_UFCON, cfg->ufcon | S3C2410_UFCON_RESETBOTH);
wr_regl(port, S3C2410_UFCON, cfg->ufcon);
return 0;
}
static struct s3c24xx_uart_info s3c2440_uart_inf = {
.name = "Samsung S3C2440 UART",
.type = PORT_S3C2440,
.fifosize = 64,
.rx_fifomask = S3C2440_UFSTAT_RXMASK,
.rx_fifoshift = S3C2440_UFSTAT_RXSHIFT,
.rx_fifofull = S3C2440_UFSTAT_RXFULL,
.tx_fifofull = S3C2440_UFSTAT_TXFULL,
.tx_fifomask = S3C2440_UFSTAT_TXMASK,
.tx_fifoshift = S3C2440_UFSTAT_TXSHIFT,
.get_clksrc = s3c2440_serial_getsource,
.set_clksrc = s3c2440_serial_setsource,
.reset_port = s3c2440_serial_resetport,
};
/* device management */
static int s3c2440_serial_probe(struct platform_device *dev)
{
dbg("s3c2440_serial_probe: dev=%p\n", dev);
return s3c24xx_serial_probe(dev, &s3c2440_uart_inf);
}
static struct platform_driver s3c2440_serial_driver = {
.probe = s3c2440_serial_probe,
.remove = __devexit_p(s3c24xx_serial_remove),
.driver = {
.name = "s3c2440-uart",
.owner = THIS_MODULE,
},
};
s3c24xx_console_init(&s3c2440_serial_driver, &s3c2440_uart_inf);
static int __init s3c2440_serial_init(void)
{
return s3c24xx_serial_init(&s3c2440_serial_driver, &s3c2440_uart_inf);
}
static void __exit s3c2440_serial_exit(void)
{
platform_driver_unregister(&s3c2440_serial_driver);
}
module_init(s3c2440_serial_init);
module_exit(s3c2440_serial_exit);
MODULE_DESCRIPTION("Samsung S3C2440,S3C2442 SoC Serial port driver");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:s3c2440-uart");
