linux/drivers/tty/serial/s5pv210.c
Boojin Kim 470f229754 ARM: SAMSUNG: serial: Fix on handling of one clock source for UART
This patch fixes the way of comparison for handling of two or more
clock sources for UART.

For example, if just only one clock source is defined even though
there are two clock sources for UART, the serial driver does not
set proper clock up. Of course, it is problem.

So this patch changes the condition of comparison to avoid useless
setup clock and adds a flag 'NO_NEED_CHECK_CLKSRC' which means
selection of source clock is not required.

In addition, since the Exynos4210 has only one clock source for UART
this patch adds the flag into its common_init_uarts().

Signed-off-by: Boojin Kim <boojin.kim@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-07 09:25:34 -07:00

162 lines
3.9 KiB
C

/*
* Copyright (c) 2010 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Based on drivers/serial/s3c6400.c
*
* Driver for Samsung S5PV210 SoC UARTs.
*
* 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 "samsung.h"
static int s5pv210_serial_setsource(struct uart_port *port,
struct s3c24xx_uart_clksrc *clk)
{
struct s3c2410_uartcfg *cfg = port->dev->platform_data;
unsigned long ucon = rd_regl(port, S3C2410_UCON);
if (cfg->flags & NO_NEED_CHECK_CLKSRC)
return 0;
if (strcmp(clk->name, "pclk") == 0)
ucon &= ~S5PV210_UCON_CLKMASK;
else if (strcmp(clk->name, "uclk1") == 0)
ucon |= S5PV210_UCON_CLKMASK;
else {
printk(KERN_ERR "unknown clock source %s\n", clk->name);
return -EINVAL;
}
wr_regl(port, S3C2410_UCON, ucon);
return 0;
}
static int s5pv210_serial_getsource(struct uart_port *port,
struct s3c24xx_uart_clksrc *clk)
{
struct s3c2410_uartcfg *cfg = port->dev->platform_data;
u32 ucon = rd_regl(port, S3C2410_UCON);
clk->divisor = 1;
if (cfg->flags & NO_NEED_CHECK_CLKSRC)
return 0;
switch (ucon & S5PV210_UCON_CLKMASK) {
case S5PV210_UCON_PCLK:
clk->name = "pclk";
break;
case S5PV210_UCON_UCLK:
clk->name = "uclk1";
break;
}
return 0;
}
static int s5pv210_serial_resetport(struct uart_port *port,
struct s3c2410_uartcfg *cfg)
{
unsigned long ucon = rd_regl(port, S3C2410_UCON);
ucon &= S5PV210_UCON_CLKMASK;
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;
}
#define S5PV210_UART_DEFAULT_INFO(fifo_size) \
.name = "Samsung S5PV210 UART0", \
.type = PORT_S3C6400, \
.fifosize = fifo_size, \
.has_divslot = 1, \
.rx_fifomask = S5PV210_UFSTAT_RXMASK, \
.rx_fifoshift = S5PV210_UFSTAT_RXSHIFT, \
.rx_fifofull = S5PV210_UFSTAT_RXFULL, \
.tx_fifofull = S5PV210_UFSTAT_TXFULL, \
.tx_fifomask = S5PV210_UFSTAT_TXMASK, \
.tx_fifoshift = S5PV210_UFSTAT_TXSHIFT, \
.get_clksrc = s5pv210_serial_getsource, \
.set_clksrc = s5pv210_serial_setsource, \
.reset_port = s5pv210_serial_resetport
static struct s3c24xx_uart_info s5p_port_fifo256 = {
S5PV210_UART_DEFAULT_INFO(256),
};
static struct s3c24xx_uart_info s5p_port_fifo64 = {
S5PV210_UART_DEFAULT_INFO(64),
};
static struct s3c24xx_uart_info s5p_port_fifo16 = {
S5PV210_UART_DEFAULT_INFO(16),
};
static struct s3c24xx_uart_info *s5p_uart_inf[] = {
[0] = &s5p_port_fifo256,
[1] = &s5p_port_fifo64,
[2] = &s5p_port_fifo16,
[3] = &s5p_port_fifo16,
};
/* device management */
static int s5p_serial_probe(struct platform_device *pdev)
{
return s3c24xx_serial_probe(pdev, s5p_uart_inf[pdev->id]);
}
static struct platform_driver s5p_serial_driver = {
.probe = s5p_serial_probe,
.remove = __devexit_p(s3c24xx_serial_remove),
.driver = {
.name = "s5pv210-uart",
.owner = THIS_MODULE,
},
};
static int __init s5pv210_serial_console_init(void)
{
return s3c24xx_serial_initconsole(&s5p_serial_driver, s5p_uart_inf);
}
console_initcall(s5pv210_serial_console_init);
static int __init s5p_serial_init(void)
{
return s3c24xx_serial_init(&s5p_serial_driver, *s5p_uart_inf);
}
static void __exit s5p_serial_exit(void)
{
platform_driver_unregister(&s5p_serial_driver);
}
module_init(s5p_serial_init);
module_exit(s5p_serial_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:s5pv210-uart");
MODULE_DESCRIPTION("Samsung S5PV210 UART Driver support");
MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com>");