rtc: ds1307: add support for watchdog timer on ds1388 (fd90d48d) · Commits · 戴 / test

drivers/rtc/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -238,6 +238,7 @@ config RTC_DRV_AS3722
		config RTC_DRV_DS1307
		tristate "Dallas/Maxim DS1307/37/38/39/40/41, ST M41T00, EPSON RX-8025, ISL12057"
		select REGMAP_I2C
		select WATCHDOG_CORE if WATCHDOG
		help
		If you say yes here you get support for various compatible RTC
		chips (often with battery backup) connected with I2C. This driver

drivers/rtc/rtc-ds1307.c

+115 −0

Original line number	Diff line number	Diff line
		@@ -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;

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