281 строка
6.3 KiB
C
281 строка
6.3 KiB
C
/*
|
|
* Driver for Atmel SAMA5D4 Watchdog Timer
|
|
*
|
|
* Copyright (C) 2015 Atmel Corporation
|
|
*
|
|
* Licensed under GPLv2.
|
|
*/
|
|
|
|
#include <linux/interrupt.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_irq.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/watchdog.h>
|
|
|
|
#include "at91sam9_wdt.h"
|
|
|
|
/* minimum and maximum watchdog timeout, in seconds */
|
|
#define MIN_WDT_TIMEOUT 1
|
|
#define MAX_WDT_TIMEOUT 16
|
|
#define WDT_DEFAULT_TIMEOUT MAX_WDT_TIMEOUT
|
|
|
|
#define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0)
|
|
|
|
struct sama5d4_wdt {
|
|
struct watchdog_device wdd;
|
|
void __iomem *reg_base;
|
|
u32 config;
|
|
};
|
|
|
|
static int wdt_timeout = WDT_DEFAULT_TIMEOUT;
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
|
|
module_param(wdt_timeout, int, 0);
|
|
MODULE_PARM_DESC(wdt_timeout,
|
|
"Watchdog timeout in seconds. (default = "
|
|
__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
|
|
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
#define wdt_read(wdt, field) \
|
|
readl_relaxed((wdt)->reg_base + (field))
|
|
|
|
#define wdt_write(wtd, field, val) \
|
|
writel_relaxed((val), (wdt)->reg_base + (field))
|
|
|
|
static int sama5d4_wdt_start(struct watchdog_device *wdd)
|
|
{
|
|
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
|
|
u32 reg;
|
|
|
|
reg = wdt_read(wdt, AT91_WDT_MR);
|
|
reg &= ~AT91_WDT_WDDIS;
|
|
wdt_write(wdt, AT91_WDT_MR, reg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sama5d4_wdt_stop(struct watchdog_device *wdd)
|
|
{
|
|
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
|
|
u32 reg;
|
|
|
|
reg = wdt_read(wdt, AT91_WDT_MR);
|
|
reg |= AT91_WDT_WDDIS;
|
|
wdt_write(wdt, AT91_WDT_MR, reg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sama5d4_wdt_ping(struct watchdog_device *wdd)
|
|
{
|
|
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
|
|
|
|
wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
|
|
unsigned int timeout)
|
|
{
|
|
struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
|
|
u32 value = WDT_SEC2TICKS(timeout);
|
|
u32 reg;
|
|
|
|
reg = wdt_read(wdt, AT91_WDT_MR);
|
|
reg &= ~AT91_WDT_WDV;
|
|
reg &= ~AT91_WDT_WDD;
|
|
reg |= AT91_WDT_SET_WDV(value);
|
|
reg |= AT91_WDT_SET_WDD(value);
|
|
wdt_write(wdt, AT91_WDT_MR, reg);
|
|
|
|
wdd->timeout = timeout;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct watchdog_info sama5d4_wdt_info = {
|
|
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
|
|
.identity = "Atmel SAMA5D4 Watchdog",
|
|
};
|
|
|
|
static struct watchdog_ops sama5d4_wdt_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = sama5d4_wdt_start,
|
|
.stop = sama5d4_wdt_stop,
|
|
.ping = sama5d4_wdt_ping,
|
|
.set_timeout = sama5d4_wdt_set_timeout,
|
|
};
|
|
|
|
static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
|
|
{
|
|
struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id);
|
|
|
|
if (wdt_read(wdt, AT91_WDT_SR)) {
|
|
pr_crit("Atmel Watchdog Software Reset\n");
|
|
emergency_restart();
|
|
pr_crit("Reboot didn't succeed\n");
|
|
}
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
|
|
{
|
|
const char *tmp;
|
|
|
|
wdt->config = AT91_WDT_WDDIS;
|
|
|
|
if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
|
|
!strcmp(tmp, "software"))
|
|
wdt->config |= AT91_WDT_WDFIEN;
|
|
else
|
|
wdt->config |= AT91_WDT_WDRSTEN;
|
|
|
|
if (of_property_read_bool(np, "atmel,idle-halt"))
|
|
wdt->config |= AT91_WDT_WDIDLEHLT;
|
|
|
|
if (of_property_read_bool(np, "atmel,dbg-halt"))
|
|
wdt->config |= AT91_WDT_WDDBGHLT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
|
|
{
|
|
struct watchdog_device *wdd = &wdt->wdd;
|
|
u32 value = WDT_SEC2TICKS(wdd->timeout);
|
|
u32 reg;
|
|
|
|
/*
|
|
* Because the fields WDV and WDD must not be modified when the WDDIS
|
|
* bit is set, so clear the WDDIS bit before writing the WDT_MR.
|
|
*/
|
|
reg = wdt_read(wdt, AT91_WDT_MR);
|
|
reg &= ~AT91_WDT_WDDIS;
|
|
wdt_write(wdt, AT91_WDT_MR, reg);
|
|
|
|
reg = wdt->config;
|
|
reg |= AT91_WDT_SET_WDD(value);
|
|
reg |= AT91_WDT_SET_WDV(value);
|
|
|
|
wdt_write(wdt, AT91_WDT_MR, reg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sama5d4_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct watchdog_device *wdd;
|
|
struct sama5d4_wdt *wdt;
|
|
struct resource *res;
|
|
void __iomem *regs;
|
|
u32 irq = 0;
|
|
int ret;
|
|
|
|
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
|
|
if (!wdt)
|
|
return -ENOMEM;
|
|
|
|
wdd = &wdt->wdd;
|
|
wdd->timeout = wdt_timeout;
|
|
wdd->info = &sama5d4_wdt_info;
|
|
wdd->ops = &sama5d4_wdt_ops;
|
|
wdd->min_timeout = MIN_WDT_TIMEOUT;
|
|
wdd->max_timeout = MAX_WDT_TIMEOUT;
|
|
|
|
watchdog_set_drvdata(wdd, wdt);
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
regs = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(regs))
|
|
return PTR_ERR(regs);
|
|
|
|
wdt->reg_base = regs;
|
|
|
|
if (pdev->dev.of_node) {
|
|
irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
|
|
if (!irq)
|
|
dev_warn(&pdev->dev, "failed to get IRQ from DT\n");
|
|
|
|
ret = of_sama5d4_wdt_init(pdev->dev.of_node, wdt);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if ((wdt->config & AT91_WDT_WDFIEN) && irq) {
|
|
ret = devm_request_irq(&pdev->dev, irq, sama5d4_wdt_irq_handler,
|
|
IRQF_SHARED | IRQF_IRQPOLL |
|
|
IRQF_NO_SUSPEND, pdev->name, pdev);
|
|
if (ret) {
|
|
dev_err(&pdev->dev,
|
|
"cannot register interrupt handler\n");
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = watchdog_init_timeout(wdd, wdt_timeout, &pdev->dev);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "unable to set timeout value\n");
|
|
return ret;
|
|
}
|
|
|
|
ret = sama5d4_wdt_init(wdt);
|
|
if (ret)
|
|
return ret;
|
|
|
|
watchdog_set_nowayout(wdd, nowayout);
|
|
|
|
ret = watchdog_register_device(wdd);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "failed to register watchdog device\n");
|
|
return ret;
|
|
}
|
|
|
|
platform_set_drvdata(pdev, wdt);
|
|
|
|
dev_info(&pdev->dev, "initialized (timeout = %d sec, nowayout = %d)\n",
|
|
wdt_timeout, nowayout);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sama5d4_wdt_remove(struct platform_device *pdev)
|
|
{
|
|
struct sama5d4_wdt *wdt = platform_get_drvdata(pdev);
|
|
|
|
sama5d4_wdt_stop(&wdt->wdd);
|
|
|
|
watchdog_unregister_device(&wdt->wdd);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id sama5d4_wdt_of_match[] = {
|
|
{ .compatible = "atmel,sama5d4-wdt", },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
|
|
|
|
static struct platform_driver sama5d4_wdt_driver = {
|
|
.probe = sama5d4_wdt_probe,
|
|
.remove = sama5d4_wdt_remove,
|
|
.driver = {
|
|
.name = "sama5d4_wdt",
|
|
.of_match_table = sama5d4_wdt_of_match,
|
|
}
|
|
};
|
|
module_platform_driver(sama5d4_wdt_driver);
|
|
|
|
MODULE_AUTHOR("Atmel Corporation");
|
|
MODULE_DESCRIPTION("Atmel SAMA5D4 Watchdog Timer driver");
|
|
MODULE_LICENSE("GPL v2");
|