196 строки
4.7 KiB
C
196 строки
4.7 KiB
C
/*
|
|
* Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer
|
|
*
|
|
* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
|
|
* Copyright (C) 2013 John Crispin <john@phrozen.org>
|
|
*
|
|
* This driver was based on: drivers/watchdog/softdog.c
|
|
*
|
|
* 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/reset.h>
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/mod_devicetable.h>
|
|
|
|
#include <asm/mach-ralink/ralink_regs.h>
|
|
|
|
#define SYSC_RSTSTAT 0x38
|
|
#define WDT_RST_CAUSE BIT(1)
|
|
|
|
#define RALINK_WDT_TIMEOUT 30
|
|
#define RALINK_WDT_PRESCALE 65536
|
|
|
|
#define TIMER_REG_TMR1LOAD 0x00
|
|
#define TIMER_REG_TMR1CTL 0x08
|
|
|
|
#define TMRSTAT_TMR1RST BIT(5)
|
|
|
|
#define TMR1CTL_ENABLE BIT(7)
|
|
#define TMR1CTL_MODE_SHIFT 4
|
|
#define TMR1CTL_MODE_MASK 0x3
|
|
#define TMR1CTL_MODE_FREE_RUNNING 0x0
|
|
#define TMR1CTL_MODE_PERIODIC 0x1
|
|
#define TMR1CTL_MODE_TIMEOUT 0x2
|
|
#define TMR1CTL_MODE_WDT 0x3
|
|
#define TMR1CTL_PRESCALE_MASK 0xf
|
|
#define TMR1CTL_PRESCALE_65536 0xf
|
|
|
|
static struct clk *rt288x_wdt_clk;
|
|
static unsigned long rt288x_wdt_freq;
|
|
static void __iomem *rt288x_wdt_base;
|
|
static struct reset_control *rt288x_wdt_reset;
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
static inline void rt_wdt_w32(unsigned reg, u32 val)
|
|
{
|
|
iowrite32(val, rt288x_wdt_base + reg);
|
|
}
|
|
|
|
static inline u32 rt_wdt_r32(unsigned reg)
|
|
{
|
|
return ioread32(rt288x_wdt_base + reg);
|
|
}
|
|
|
|
static int rt288x_wdt_ping(struct watchdog_device *w)
|
|
{
|
|
rt_wdt_w32(TIMER_REG_TMR1LOAD, w->timeout * rt288x_wdt_freq);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rt288x_wdt_start(struct watchdog_device *w)
|
|
{
|
|
u32 t;
|
|
|
|
t = rt_wdt_r32(TIMER_REG_TMR1CTL);
|
|
t &= ~(TMR1CTL_MODE_MASK << TMR1CTL_MODE_SHIFT |
|
|
TMR1CTL_PRESCALE_MASK);
|
|
t |= (TMR1CTL_MODE_WDT << TMR1CTL_MODE_SHIFT |
|
|
TMR1CTL_PRESCALE_65536);
|
|
rt_wdt_w32(TIMER_REG_TMR1CTL, t);
|
|
|
|
rt288x_wdt_ping(w);
|
|
|
|
t = rt_wdt_r32(TIMER_REG_TMR1CTL);
|
|
t |= TMR1CTL_ENABLE;
|
|
rt_wdt_w32(TIMER_REG_TMR1CTL, t);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rt288x_wdt_stop(struct watchdog_device *w)
|
|
{
|
|
u32 t;
|
|
|
|
rt288x_wdt_ping(w);
|
|
|
|
t = rt_wdt_r32(TIMER_REG_TMR1CTL);
|
|
t &= ~TMR1CTL_ENABLE;
|
|
rt_wdt_w32(TIMER_REG_TMR1CTL, t);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rt288x_wdt_set_timeout(struct watchdog_device *w, unsigned int t)
|
|
{
|
|
w->timeout = t;
|
|
rt288x_wdt_ping(w);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rt288x_wdt_bootcause(void)
|
|
{
|
|
if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE)
|
|
return WDIOF_CARDRESET;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct watchdog_info rt288x_wdt_info = {
|
|
.identity = "Ralink Watchdog",
|
|
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
|
|
};
|
|
|
|
static const struct watchdog_ops rt288x_wdt_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = rt288x_wdt_start,
|
|
.stop = rt288x_wdt_stop,
|
|
.ping = rt288x_wdt_ping,
|
|
.set_timeout = rt288x_wdt_set_timeout,
|
|
};
|
|
|
|
static struct watchdog_device rt288x_wdt_dev = {
|
|
.info = &rt288x_wdt_info,
|
|
.ops = &rt288x_wdt_ops,
|
|
.min_timeout = 1,
|
|
};
|
|
|
|
static int rt288x_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
int ret;
|
|
|
|
rt288x_wdt_base = devm_platform_ioremap_resource(pdev, 0);
|
|
if (IS_ERR(rt288x_wdt_base))
|
|
return PTR_ERR(rt288x_wdt_base);
|
|
|
|
rt288x_wdt_clk = devm_clk_get(dev, NULL);
|
|
if (IS_ERR(rt288x_wdt_clk))
|
|
return PTR_ERR(rt288x_wdt_clk);
|
|
|
|
rt288x_wdt_reset = devm_reset_control_get_exclusive(dev, NULL);
|
|
if (!IS_ERR(rt288x_wdt_reset))
|
|
reset_control_deassert(rt288x_wdt_reset);
|
|
|
|
rt288x_wdt_freq = clk_get_rate(rt288x_wdt_clk) / RALINK_WDT_PRESCALE;
|
|
|
|
rt288x_wdt_dev.bootstatus = rt288x_wdt_bootcause();
|
|
rt288x_wdt_dev.max_timeout = (0xfffful / rt288x_wdt_freq);
|
|
rt288x_wdt_dev.parent = dev;
|
|
|
|
watchdog_init_timeout(&rt288x_wdt_dev, rt288x_wdt_dev.max_timeout,
|
|
dev);
|
|
watchdog_set_nowayout(&rt288x_wdt_dev, nowayout);
|
|
|
|
watchdog_stop_on_reboot(&rt288x_wdt_dev);
|
|
ret = devm_watchdog_register_device(dev, &rt288x_wdt_dev);
|
|
if (!ret)
|
|
dev_info(dev, "Initialized\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id rt288x_wdt_match[] = {
|
|
{ .compatible = "ralink,rt2880-wdt" },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, rt288x_wdt_match);
|
|
|
|
static struct platform_driver rt288x_wdt_driver = {
|
|
.probe = rt288x_wdt_probe,
|
|
.driver = {
|
|
.name = KBUILD_MODNAME,
|
|
.of_match_table = rt288x_wdt_match,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(rt288x_wdt_driver);
|
|
|
|
MODULE_DESCRIPTION("MediaTek/Ralink RT288x/RT3xxx hardware watchdog driver");
|
|
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org");
|
|
MODULE_LICENSE("GPL v2");
|