static int dw_wdt_open(struct inode *inode, struct file *filp)
{
if (test_and_set_bit(0, &dw_wdt.in_use))
return -EBUSY;
/* Make sure we don't get unloaded. */
__module_get(THIS_MODULE);
spin_lock(&dw_wdt.lock);
if (!dw_wdt_is_enabled()) {
/*
* The watchdog is not currently enabled. Set the timeout to
* the maximum and then start it.
*/
dw_wdt_set_top(DW_WDT_MAX_TOP);
writel(WDOG_CONTROL_REG_WDT_EN_MASK,
dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
}
dw_wdt_set_next_heartbeat();
spin_unlock(&dw_wdt.lock);
return nonseekable_open(inode, filp);
}
static int dw_wdt_restart(struct watchdog_device *wdd,
unsigned long action, void *data)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
writel(0, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
if (dw_wdt_is_enabled(dw_wdt))
writel(WDOG_COUNTER_RESTART_KICK_VALUE,
dw_wdt->regs + WDOG_COUNTER_RESTART_REG_OFFSET);
else
dw_wdt_arm_system_reset(dw_wdt);
/* wait for reset to assert... */
mdelay(500);
return 0;
}
static int dw_wdt_open(struct inode *inode, struct file *filp)
{
if (test_and_set_bit(0, &dw_wdt.in_use))
return -EBUSY;
__module_get(THIS_MODULE);
spin_lock(&dw_wdt.lock);
if (!dw_wdt_is_enabled()) {
dw_wdt_set_top(DW_WDT_MAX_TOP);
writel(WDOG_CONTROL_REG_WDT_EN_MASK,
dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
}
dw_wdt_set_next_heartbeat();
spin_unlock(&dw_wdt.lock);
return nonseekable_open(inode, filp);
}
static int dw_wdt_drv_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct watchdog_device *wdd;
struct dw_wdt *dw_wdt;
struct resource *mem;
int ret;
dw_wdt = devm_kzalloc(dev, sizeof(*dw_wdt), GFP_KERNEL);
if (!dw_wdt)
return -ENOMEM;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dw_wdt->regs = devm_ioremap_resource(dev, mem);
if (IS_ERR(dw_wdt->regs))
return PTR_ERR(dw_wdt->regs);
dw_wdt->clk = devm_clk_get(dev, NULL);
if (IS_ERR(dw_wdt->clk))
return PTR_ERR(dw_wdt->clk);
ret = clk_prepare_enable(dw_wdt->clk);
if (ret)
return ret;
dw_wdt->rate = clk_get_rate(dw_wdt->clk);
if (dw_wdt->rate == 0) {
ret = -EINVAL;
goto out_disable_clk;
}
dw_wdt->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
if (IS_ERR(dw_wdt->rst)) {
ret = PTR_ERR(dw_wdt->rst);
goto out_disable_clk;
}
reset_control_deassert(dw_wdt->rst);
wdd = &dw_wdt->wdd;
wdd->info = &dw_wdt_ident;
wdd->ops = &dw_wdt_ops;
wdd->min_timeout = 1;
wdd->max_hw_heartbeat_ms =
dw_wdt_top_in_seconds(dw_wdt, DW_WDT_MAX_TOP) * 1000;
wdd->parent = dev;
watchdog_set_drvdata(wdd, dw_wdt);
watchdog_set_nowayout(wdd, nowayout);
watchdog_init_timeout(wdd, 0, dev);
/*
* If the watchdog is already running, use its already configured
* timeout. Otherwise use the default or the value provided through
* devicetree.
*/
if (dw_wdt_is_enabled(dw_wdt)) {
wdd->timeout = dw_wdt_get_top(dw_wdt);
set_bit(WDOG_HW_RUNNING, &wdd->status);
} else {
wdd->timeout = DW_WDT_DEFAULT_SECONDS;
watchdog_init_timeout(wdd, 0, dev);
}
platform_set_drvdata(pdev, dw_wdt);
watchdog_set_restart_priority(wdd, 128);
ret = watchdog_register_device(wdd);
if (ret)
goto out_disable_clk;
return 0;
out_disable_clk:
clk_disable_unprepare(dw_wdt->clk);
return ret;
}
