diff options
Diffstat (limited to 'drivers/rtc/rtc-abx80x.c')
-rw-r--r-- | drivers/rtc/rtc-abx80x.c | 143 |
1 files changed, 131 insertions, 12 deletions
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c index 2cefa67a1132..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 @@ -80,20 +90,27 @@ 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) { int flags = 0; @@ -218,7 +235,8 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm) static irqreturn_t abx80x_handle_irq(int irq, void *dev_id) { struct i2c_client *client = dev_id; - struct rtc_device *rtc = i2c_get_clientdata(client); + struct abx80x_priv *priv = i2c_get_clientdata(client); + struct rtc_device *rtc = priv->rtc; int status; status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS); @@ -228,6 +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; @@ -529,11 +554,94 @@ 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) { struct device_node *np = client->dev.of_node; - struct rtc_device *rtc; + struct abx80x_priv *priv; int i, data, err, trickle_cfg = -EINVAL; char buf[7]; unsigned int part = id->driver_data; @@ -610,13 +718,24 @@ static int abx80x_probe(struct i2c_client *client, if (err) return err; - rtc = devm_rtc_allocate_device(&client->dev); - if (IS_ERR(rtc)) - return PTR_ERR(rtc); + priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); + if (priv == NULL) + return -ENOMEM; + + priv->rtc = devm_rtc_allocate_device(&client->dev); + if (IS_ERR(priv->rtc)) + return PTR_ERR(priv->rtc); + + priv->rtc->ops = &abx80x_rtc_ops; + priv->client = client; - rtc->ops = &abx80x_rtc_ops; + i2c_set_clientdata(client, priv); - i2c_set_clientdata(client, rtc); + 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); @@ -649,7 +768,7 @@ static int abx80x_probe(struct i2c_client *client, return err; } - err = rtc_register_device(rtc); + err = rtc_register_device(priv->rtc); return err; } |