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authorWolfram Sang <wsa+renesas@sang-engineering.com>2020-09-08 12:56:15 +0300
committerWim Van Sebroeck <wim@linux-watchdog.org>2020-10-14 16:22:56 +0300
commit962085a2bb823d8c88c6bc706c654648407e6408 (patch)
tree299377f5219336b50ee3b87adfb4e4b07bc6379b /drivers/watchdog/renesas_wdt.c
parent0cfbe17959b69896a72dffbc2d37280859b0d086 (diff)
downloadlinux-962085a2bb823d8c88c6bc706c654648407e6408.tar.xz
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>
Diffstat (limited to 'drivers/watchdog/renesas_wdt.c')
-rw-r--r--drivers/watchdog/renesas_wdt.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
index 00662a8e039c..47fce4de0110 100644
--- a/drivers/watchdog/renesas_wdt.c
+++ b/drivers/watchdog/renesas_wdt.c
@@ -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;