mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 15:43:59 +08:00
a4658e57a7
This patch adds a watchdog reset driver that can be used on Samsung SoCs that do not provide dedicated reset method. It replaces the legacy helper function that relies on static IO mapping. Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com> Tested-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
98 lines
2.3 KiB
C
98 lines
2.3 KiB
C
/* arch/arm/plat-samsung/watchdog-reset.c
|
|
*
|
|
* Copyright (c) 2008 Simtec Electronics
|
|
* Ben Dooks <ben@simtec.co.uk>
|
|
*
|
|
* Coyright (c) 2013 Tomasz Figa <tomasz.figa@gmail.com>
|
|
*
|
|
* Watchdog reset support for Samsung SoCs.
|
|
*
|
|
* 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/clk.h>
|
|
#include <linux/err.h>
|
|
#include <linux/io.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_address.h>
|
|
|
|
#define S3C2410_WTCON 0x00
|
|
#define S3C2410_WTDAT 0x04
|
|
#define S3C2410_WTCNT 0x08
|
|
|
|
#define S3C2410_WTCON_ENABLE (1 << 5)
|
|
#define S3C2410_WTCON_DIV16 (0 << 3)
|
|
#define S3C2410_WTCON_RSTEN (1 << 0)
|
|
#define S3C2410_WTCON_PRESCALE(x) ((x) << 8)
|
|
|
|
static void __iomem *wdt_base;
|
|
static struct clk *wdt_clock;
|
|
|
|
void samsung_wdt_reset(void)
|
|
{
|
|
if (!wdt_base) {
|
|
pr_err("%s: wdt reset not initialized\n", __func__);
|
|
/* delay to allow the serial port to show the message */
|
|
mdelay(50);
|
|
return;
|
|
}
|
|
|
|
if (!IS_ERR(wdt_clock))
|
|
clk_prepare_enable(wdt_clock);
|
|
|
|
/* disable watchdog, to be safe */
|
|
__raw_writel(0, wdt_base + S3C2410_WTCON);
|
|
|
|
/* put initial values into count and data */
|
|
__raw_writel(0x80, wdt_base + S3C2410_WTCNT);
|
|
__raw_writel(0x80, wdt_base + S3C2410_WTDAT);
|
|
|
|
/* set the watchdog to go and reset... */
|
|
__raw_writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
|
|
S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
|
|
wdt_base + S3C2410_WTCON);
|
|
|
|
/* wait for reset to assert... */
|
|
mdelay(500);
|
|
|
|
pr_err("Watchdog reset failed to assert reset\n");
|
|
|
|
/* delay to allow the serial port to show the message */
|
|
mdelay(50);
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id s3c2410_wdt_match[] = {
|
|
{ .compatible = "samsung,s3c2410-wdt" },
|
|
{},
|
|
};
|
|
|
|
void __init samsung_wdt_reset_of_init(void)
|
|
{
|
|
struct device_node *np;
|
|
|
|
np = of_find_matching_node(NULL, s3c2410_wdt_match);
|
|
if (!np) {
|
|
pr_err("%s: failed to find watchdog node\n", __func__);
|
|
return;
|
|
}
|
|
|
|
wdt_base = of_iomap(np, 0);
|
|
if (!wdt_base) {
|
|
pr_err("%s: failed to map watchdog registers\n", __func__);
|
|
return;
|
|
}
|
|
|
|
wdt_clock = of_clk_get(np, 0);
|
|
}
|
|
#endif
|
|
|
|
void __init samsung_wdt_reset_init(void __iomem *base)
|
|
{
|
|
wdt_base = base;
|
|
wdt_clock = clk_get(NULL, "watchdog");
|
|
}
|