diff options
Diffstat (limited to 'drivers/rtc/rtc-ds1307.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1307.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 31a38d468378..fad042118862 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -22,6 +22,7 @@ #include <linux/hwmon-sysfs.h> #include <linux/clk-provider.h> #include <linux/regmap.h> +#include <linux/watchdog.h> /* * We can't determine type by probing, but if we expect pre-Linux code @@ -144,8 +145,15 @@ enum ds_type { # define M41TXX_BIT_CALIB_SIGN BIT(5) # define M41TXX_M_CALIBRATION GENMASK(4, 0) +#define DS1388_REG_WDOG_HUN_SECS 0x08 +#define DS1388_REG_WDOG_SECS 0x09 #define DS1388_REG_FLAG 0x0b +# define DS1388_BIT_WF BIT(6) # define DS1388_BIT_OSF BIT(7) +#define DS1388_REG_CONTROL 0x0c +# define DS1388_BIT_RST BIT(0) +# define DS1388_BIT_WDE BIT(1) + /* negative offset step is -2.034ppm */ #define M41TXX_NEG_OFFSET_STEP_PPB 2034 /* positive offset step is +4.068ppm */ @@ -854,6 +862,72 @@ static int m41txx_rtc_set_offset(struct device *dev, long offset) ctrl_reg); } +#ifdef CONFIG_WATCHDOG_CORE +static int ds1388_wdt_start(struct watchdog_device *wdt_dev) +{ + struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev); + u8 regs[2]; + int ret; + + ret = regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG, + DS1388_BIT_WF, 0); + if (ret) + return ret; + + ret = regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL, + DS1388_BIT_WDE | DS1388_BIT_RST, 0); + if (ret) + return ret; + + /* + * watchdog timeouts are measured in seconds. So ignore hundredths of + * seconds field. + */ + regs[0] = 0; + regs[1] = bin2bcd(wdt_dev->timeout); + + ret = regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs, + sizeof(regs)); + if (ret) + return ret; + + return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL, + DS1388_BIT_WDE | DS1388_BIT_RST, + DS1388_BIT_WDE | DS1388_BIT_RST); +} + +static int ds1388_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev); + + return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL, + DS1388_BIT_WDE | DS1388_BIT_RST, 0); +} + +static int ds1388_wdt_ping(struct watchdog_device *wdt_dev) +{ + struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev); + u8 regs[2]; + + return regmap_bulk_read(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs, + sizeof(regs)); +} + +static int ds1388_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int val) +{ + struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev); + u8 regs[2]; + + wdt_dev->timeout = val; + regs[0] = 0; + regs[1] = bin2bcd(wdt_dev->timeout); + + return regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs, + sizeof(regs)); +} +#endif + static const struct rtc_class_ops rx8130_rtc_ops = { .read_time = ds1307_get_time, .set_time = ds1307_set_time, @@ -1576,6 +1650,46 @@ static void ds1307_clks_register(struct ds1307 *ds1307) #endif /* CONFIG_COMMON_CLK */ +#ifdef CONFIG_WATCHDOG_CORE +static const struct watchdog_info ds1388_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "DS1388 watchdog", +}; + +static const struct watchdog_ops ds1388_wdt_ops = { + .owner = THIS_MODULE, + .start = ds1388_wdt_start, + .stop = ds1388_wdt_stop, + .ping = ds1388_wdt_ping, + .set_timeout = ds1388_wdt_set_timeout, + +}; + +static void ds1307_wdt_register(struct ds1307 *ds1307) +{ + struct watchdog_device *wdt; + + if (ds1307->type != ds_1388) + return; + + wdt = devm_kzalloc(ds1307->dev, sizeof(*wdt), GFP_KERNEL); + + wdt->info = &ds1388_wdt_info; + wdt->ops = &ds1388_wdt_ops; + wdt->timeout = 99; + wdt->max_timeout = 99; + wdt->min_timeout = 1; + + watchdog_init_timeout(wdt, 0, ds1307->dev); + watchdog_set_drvdata(wdt, ds1307); + devm_watchdog_register_device(ds1307->dev, wdt); +} +#else +static void ds1307_wdt_register(struct ds1307 *ds1307) +{ +} +#endif /* CONFIG_WATCHDOG_CORE */ + static const struct regmap_config regmap_config = { .reg_bits = 8, .val_bits = 8, @@ -1865,6 +1979,7 @@ static int ds1307_probe(struct i2c_client *client, ds1307_hwmon_register(ds1307); ds1307_clks_register(ds1307); + ds1307_wdt_register(ds1307); return 0; |