watchdog: renesas_wdt: support handover from bootloader

Support an already running watchdog by checking its enable bit and set
up the status accordingly before registering the device.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200908095615.31376-1-wsa+renesas@sang-engineering.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
This commit is contained in:
Wolfram Sang 2020-09-08 11:56:15 +02:00 committed by Wim Van Sebroeck
parent 0cfbe17959
commit 962085a2bb
1 changed files with 10 additions and 2 deletions

View File

@ -194,6 +194,7 @@ static int rwdt_probe(struct platform_device *pdev)
struct clk *clk;
unsigned long clks_per_sec;
int ret, i;
u8 csra;
if (rwdt_blacklisted(dev))
return -ENODEV;
@ -213,8 +214,8 @@ static int rwdt_probe(struct platform_device *pdev)
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
priv->clk_rate = clk_get_rate(clk);
priv->wdev.bootstatus = (readb_relaxed(priv->base + RWTCSRA) &
RWTCSRA_WOVF) ? WDIOF_CARDRESET : 0;
csra = readb_relaxed(priv->base + RWTCSRA);
priv->wdev.bootstatus = csra & RWTCSRA_WOVF ? WDIOF_CARDRESET : 0;
pm_runtime_put(dev);
if (!priv->clk_rate) {
@ -252,6 +253,13 @@ static int rwdt_probe(struct platform_device *pdev)
/* This overrides the default timeout only if DT configuration was found */
watchdog_init_timeout(&priv->wdev, 0, dev);
/* Check if FW enabled the watchdog */
if (csra & RWTCSRA_TME) {
/* Ensure properly initialized dividers */
rwdt_start(&priv->wdev);
set_bit(WDOG_HW_RUNNING, &priv->wdev.status);
}
ret = watchdog_register_device(&priv->wdev);
if (ret < 0)
goto out_pm_disable;