On Tue, Sep 11, 2018 at 11:28:26AM -0600, Jeremy Gebben wrote: > The abx804 and abx805 chips have support for a simple watchdog > function that can trigger an external reset. > > Signed-off-by: Jeremy Gebben <[email protected]>
Reviewed-by: Guenter Roeck <[email protected]> > --- > drivers/rtc/Kconfig | 1 + > drivers/rtc/rtc-abx80x.c | 116 +++++++++++++++++++++++++++++++++++++-- > 2 files changed, 113 insertions(+), 4 deletions(-) > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 7d7be60a2413..bcb0e9eda781 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -187,6 +187,7 @@ config RTC_DRV_ABB5ZES3 > > config RTC_DRV_ABX80X > tristate "Abracon ABx80x" > + select WATCHDOG_CORE if WATCHDOG > help > If you say yes here you get support for Abracon AB080X and AB180X > families of ultra-low-power battery- and capacitor-backed real-time > diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c > index 9d49054a0a4a..d8e94edcb0ba 100644 > --- a/drivers/rtc/rtc-abx80x.c > +++ b/drivers/rtc/rtc-abx80x.c > @@ -17,6 +17,7 @@ > #include <linux/i2c.h> > #include <linux/module.h> > #include <linux/rtc.h> > +#include <linux/watchdog.h> > > #define ABX8XX_REG_HTH 0x00 > #define ABX8XX_REG_SC 0x01 > @@ -37,6 +38,7 @@ > > #define ABX8XX_REG_STATUS 0x0f > #define ABX8XX_STATUS_AF BIT(2) > +#define ABX8XX_STATUS_WDT BIT(6) > > #define ABX8XX_REG_CTRL1 0x10 > #define ABX8XX_CTRL_WRITE BIT(0) > @@ -61,6 +63,14 @@ > #define ABX8XX_OSS_OF BIT(1) > #define ABX8XX_OSS_OMODE BIT(4) > > +#define ABX8XX_REG_WDT 0x1b > +#define ABX8XX_WDT_WDS BIT(7) > +#define ABX8XX_WDT_BMB_MASK 0x7c > +#define ABX8XX_WDT_BMB_SHIFT 2 > +#define ABX8XX_WDT_MAX_TIME (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT) > +#define ABX8XX_WDT_WRB_MASK 0x03 > +#define ABX8XX_WDT_WRB_1HZ 0x02 > + > #define ABX8XX_REG_CFG_KEY 0x1f > #define ABX8XX_CFG_KEY_OSC 0xa1 > #define ABX8XX_CFG_KEY_MISC 0x9d > @@ -80,23 +90,25 @@ enum abx80x_chip {AB0801, AB0803, AB0804, AB0805, > struct abx80x_cap { > u16 pn; > bool has_tc; > + bool has_wdog; > }; > > static struct abx80x_cap abx80x_caps[] = { > [AB0801] = {.pn = 0x0801}, > [AB0803] = {.pn = 0x0803}, > - [AB0804] = {.pn = 0x0804, .has_tc = true}, > - [AB0805] = {.pn = 0x0805, .has_tc = true}, > + [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true}, > + [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true}, > [AB1801] = {.pn = 0x1801}, > [AB1803] = {.pn = 0x1803}, > - [AB1804] = {.pn = 0x1804, .has_tc = true}, > - [AB1805] = {.pn = 0x1805, .has_tc = true}, > + [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true}, > + [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true}, > [ABX80X] = {.pn = 0} > }; > > struct abx80x_priv { > struct rtc_device *rtc; > struct i2c_client *client; > + struct watchdog_device wdog; > }; > > static int abx80x_is_rc_mode(struct i2c_client *client) > @@ -234,6 +246,13 @@ static irqreturn_t abx80x_handle_irq(int irq, void > *dev_id) > if (status & ABX8XX_STATUS_AF) > rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF); > > + /* > + * It is unclear if we'll get an interrupt before the external > + * reset kicks in. > + */ > + if (status & ABX8XX_STATUS_WDT) > + dev_alert(&client->dev, "watchdog timeout interrupt.\n"); > + > i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0); > > return IRQ_HANDLED; > @@ -535,6 +554,89 @@ static void rtc_calib_remove_sysfs_group(void *_dev) > sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group); > } > > +#ifdef CONFIG_WATCHDOG > + > +static inline u8 timeout_bits(unsigned int timeout) > +{ > + return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) | > + ABX8XX_WDT_WRB_1HZ; > +} > + > +static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog, > + unsigned int timeout) > +{ > + struct abx80x_priv *priv = watchdog_get_drvdata(wdog); > + u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout); > + > + /* > + * Writing any timeout to the WDT register resets the watchdog timer. > + * Writing 0 disables it. > + */ > + return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val); > +} > + > +static int abx80x_wdog_set_timeout(struct watchdog_device *wdog, > + unsigned int new_timeout) > +{ > + int err = 0; > + > + if (watchdog_hw_running(wdog)) > + err = __abx80x_wdog_set_timeout(wdog, new_timeout); > + > + if (err == 0) > + wdog->timeout = new_timeout; > + > + return err; > +} > + > +static int abx80x_wdog_ping(struct watchdog_device *wdog) > +{ > + return __abx80x_wdog_set_timeout(wdog, wdog->timeout); > +} > + > +static int abx80x_wdog_start(struct watchdog_device *wdog) > +{ > + return __abx80x_wdog_set_timeout(wdog, wdog->timeout); > +} > + > +static int abx80x_wdog_stop(struct watchdog_device *wdog) > +{ > + return __abx80x_wdog_set_timeout(wdog, 0); > +} > + > +static const struct watchdog_info abx80x_wdog_info = { > + .identity = "abx80x watchdog", > + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, > +}; > + > +static const struct watchdog_ops abx80x_wdog_ops = { > + .owner = THIS_MODULE, > + .start = abx80x_wdog_start, > + .stop = abx80x_wdog_stop, > + .ping = abx80x_wdog_ping, > + .set_timeout = abx80x_wdog_set_timeout, > +}; > + > +static int abx80x_setup_watchdog(struct abx80x_priv *priv) > +{ > + priv->wdog.parent = &priv->client->dev; > + priv->wdog.ops = &abx80x_wdog_ops; > + priv->wdog.info = &abx80x_wdog_info; > + priv->wdog.min_timeout = 1; > + priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME; > + priv->wdog.timeout = ABX8XX_WDT_MAX_TIME; > + > + watchdog_set_drvdata(&priv->wdog, priv); > + > + return devm_watchdog_register_device(&priv->client->dev, &priv->wdog); > +} > +#else > +static int abx80x_setup_watchdog(struct abx80x_priv *priv) > +{ > + return 0; > +} > +#endif > + > static int abx80x_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -629,6 +731,12 @@ static int abx80x_probe(struct i2c_client *client, > > i2c_set_clientdata(client, priv); > > + if (abx80x_caps[part].has_wdog) { > + err = abx80x_setup_watchdog(priv); > + if (err) > + return err; > + } > + > if (client->irq > 0) { > dev_info(&client->dev, "IRQ %d supplied\n", client->irq); > err = devm_request_threaded_irq(&client->dev, client->irq, NULL, > -- > 2.17.1 >
