diff options
Diffstat (limited to 'drivers/watchdog')
| -rw-r--r-- | drivers/watchdog/renesas_wdt.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c index d8ac2299400b..00662a8e039c 100644 --- a/drivers/watchdog/renesas_wdt.c +++ b/drivers/watchdog/renesas_wdt.c @@ -7,6 +7,7 @@ */ #include <linux/bitops.h> #include <linux/clk.h> +#include <linux/delay.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> @@ -70,6 +71,15 @@ static int rwdt_init_timeout(struct watchdog_device *wdev) return 0; } +static void rwdt_wait_cycles(struct rwdt_priv *priv, unsigned int cycles) +{ + unsigned int delay; + + delay = DIV_ROUND_UP(cycles * 1000000, priv->clk_rate); + + usleep_range(delay, 2 * delay); +} + static int rwdt_start(struct watchdog_device *wdev) { struct rwdt_priv *priv = watchdog_get_drvdata(wdev); @@ -80,6 +90,8 @@ static int rwdt_start(struct watchdog_device *wdev) /* Stop the timer before we modify any register */ val = readb_relaxed(priv->base + RWTCSRA) & ~RWTCSRA_TME; rwdt_write(priv, val, RWTCSRA); + /* Delay 2 cycles before setting watchdog counter */ + rwdt_wait_cycles(priv, 2); rwdt_init_timeout(wdev); rwdt_write(priv, priv->cks, RWTCSRA); @@ -98,6 +110,8 @@ static int rwdt_stop(struct watchdog_device *wdev) struct rwdt_priv *priv = watchdog_get_drvdata(wdev); rwdt_write(priv, priv->cks, RWTCSRA); + /* Delay 3 cycles before disabling module clock */ + rwdt_wait_cycles(priv, 3); pm_runtime_put(wdev->parent); return 0; |