From cc2c60c531572ac27f42f419d3da1a65e4e67262 Mon Sep 17 00:00:00 2001 From: Enrico Scholz Date: Wed, 3 Aug 2016 16:14:51 +0200 Subject: mfd: da9063: reset watchdog timer Setting the new timeout does not suffice for restarting the watchdog; the self-clearing bit in CONTROL_F must be set too. barebox does not provide a ping function in its watchdog api to restart the watchdog timer. Detect ping vs. set_timeout() by comparing the actual with the previous timeout value. Signed-off-by: Enrico Scholz Tested-by: Stefan Christ Signed-off-by: Christian Hemp --- drivers/mfd/da9063.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-) diff --git a/drivers/mfd/da9063.c b/drivers/mfd/da9063.c index ac303611c0..74ad5bfdab 100644 --- a/drivers/mfd/da9063.c +++ b/drivers/mfd/da9063.c @@ -28,8 +28,13 @@ struct da9063 { struct watchdog wd; struct i2c_client *client; struct device_d *dev; + unsigned int timeout; }; +/* forbidden/impossible value; timeout will be set to this value initially to + * detect ping vs. set_timeout() operations. */ +#define DA9063_INITIAL_TIMEOUT (~0u) + /* System Control and Event Registers */ #define DA9063_REG_FAULT_LOG 0x05 #define DA9063_REG_CONTROL_D 0x11 @@ -44,8 +49,25 @@ struct da9063 { #define DA9063_TWDSCALE_MASK 0x07 /* DA9063_REG_CONTROL_F (addr=0x13) */ +#define DA9063_WATCHDOG 0x01 #define DA9063_SHUTDOWN 0x02 +static int da9063_watchdog_ping(struct da9063 *priv) +{ + int ret; + u8 val; + + dev_dbg(priv->dev, "ping\n"); + + /* reset watchdog timer; register is self clearing */ + val = DA9063_WATCHDOG; + ret = i2c_write_reg(priv->client, DA9063_REG_CONTROL_F, &val, 1); + if (ret < 0) + return ret; + + return 0; +} + static int da9063_watchdog_set_timeout(struct watchdog *wd, unsigned timeout) { struct da9063 *priv = container_of(wd, struct da9063, wd); @@ -57,8 +79,14 @@ static int da9063_watchdog_set_timeout(struct watchdog *wd, unsigned timeout) if (timeout > 131) return -EINVAL; + timeout *= 1000; /* convert to ms */ + + if (timeout == priv->timeout) + /* set_timeout called with previous parameter; just ping the + * watchdog */ + goto out; + if (timeout) { - timeout *= 1000; /* convert to ms */ scale = 0; while (timeout > (2048 << scale) && scale <= 6) scale++; @@ -78,7 +106,10 @@ static int da9063_watchdog_set_timeout(struct watchdog *wd, unsigned timeout) if (ret < 0) return ret; - return 0; + priv->timeout = timeout; + +out: + return da9063_watchdog_ping(priv); } static void da9063_detect_reset_source(struct da9063 *priv) @@ -127,6 +158,7 @@ static int da9063_probe(struct device_d *dev) priv->wd.priority = of_get_watchdog_priority(dev->device_node); priv->wd.set_timeout = da9063_watchdog_set_timeout; priv->wd.hwdev = dev; + priv->timeout = DA9063_INITIAL_TIMEOUT; priv->client = to_i2c_client(dev); priv->dev = dev; -- cgit v1.2.3