rtc-ds1307: alarm support for ds1337/ds1339 (cb49a5e9) · Commits · e / devices / android_kernel_xiaomi_sm6125

drivers/rtc/rtc-ds1307.c

+295 −13

Original line number	Diff line number	Diff line
		@@ -23,10 +23,6 @@
		* to have set the chip up as a clock (turning on the oscillator and
		* setting the date and time), Linux can ignore the non-clock features.
		* That's a natural job for a factory or repair bench.
		*
		* This is currently a simple no-alarms driver. If your board has the
		* alarm irq wired up on a ds1337 or ds1339, and you want to use that,
		* then look at the rtc-rs5c372 driver for code to steal...
		*/
		enum ds_type {
		ds_1307,
		@@ -67,6 +63,7 @@ enum ds_type {
		# define DS1307_BIT_RS0 0x01
		#define DS1337_REG_CONTROL 0x0e
		# define DS1337_BIT_nEOSC 0x80
		# define DS1339_BIT_BBSQI 0x20
		# define DS1337_BIT_RS2 0x10
		# define DS1337_BIT_RS1 0x08
		# define DS1337_BIT_INTCN 0x04
		@@ -83,19 +80,22 @@ enum ds_type {
		# define DS1337_BIT_OSF 0x80
		# define DS1337_BIT_A2I 0x02
		# define DS1337_BIT_A1I 0x01
		#define DS1339_REG_ALARM1_SECS 0x07
		#define DS1339_REG_TRICKLE 0x10



		struct ds1307 {
		u8 reg_addr;
		bool has_nvram;
		u8 regs[8];
		u8 regs[11];
		enum ds_type type;
		unsigned long flags;
		#define HAS_NVRAM 0 /* bit 0 == sysfs file active */
		#define HAS_ALARM 1 /* bit 1 == irq claimed */
		struct i2c_msg msg[2];
		struct i2c_client *client;
		struct i2c_client dev;
		struct rtc_device *rtc;
		struct work_struct work;
		};

		struct chip_desc {
		@@ -132,12 +132,79 @@ static const struct i2c_device_id ds1307_id[] = {
		};
		MODULE_DEVICE_TABLE(i2c, ds1307_id);

		/----------------------------------------------------------------------/

		/*
		* The IRQ logic includes a "real" handler running in IRQ context just
		* long enough to schedule this workqueue entry. We need a task context
		* to talk to the RTC, since I2C I/O calls require that; and disable the
		* IRQ until we clear its status on the chip, so that this handler can
		* work with any type of triggering (not just falling edge).
		*
		* The ds1337 and ds1339 both have two alarms, but we only use the first
		* one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
		* signal; ds1339 chips have only one alarm signal.
		*/
		static void ds1307_work(struct work_struct *work)
		{
		struct ds1307 *ds1307;
		struct i2c_client *client;
		struct mutex *lock;
		int stat, control;

		ds1307 = container_of(work, struct ds1307, work);
		client = ds1307->client;
		lock = &ds1307->rtc->ops_lock;

		mutex_lock(lock);
		stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
		if (stat < 0)
		goto out;

		if (stat & DS1337_BIT_A1I) {
		stat &= ~DS1337_BIT_A1I;
		i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);

		control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
		if (control < 0)
		goto out;

		control &= ~DS1337_BIT_A1IE;
		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);

		/* rtc_update_irq() assumes that it is called
		* from IRQ-disabled context.
		*/
		local_irq_disable();
		rtc_update_irq(ds1307->rtc, 1, RTC_AF \| RTC_IRQF);
		local_irq_enable();
		}

		out:
		if (test_bit(HAS_ALARM, &ds1307->flags))
		enable_irq(client->irq);
		mutex_unlock(lock);
		}

		static irqreturn_t ds1307_irq(int irq, void *dev_id)
		{
		struct i2c_client *client = dev_id;
		struct ds1307 *ds1307 = i2c_get_clientdata(client);

		disable_irq_nosync(irq);
		schedule_work(&ds1307->work);
		return IRQ_HANDLED;
		}

		/----------------------------------------------------------------------/

		static int ds1307_get_time(struct device dev, struct rtc_time t)
		{
		struct ds1307 *ds1307 = dev_get_drvdata(dev);
		int tmp;

		/* read the RTC date and time registers all at once */
		ds1307->reg_addr = 0;
		ds1307->msg[1].flags = I2C_M_RD;
		ds1307->msg[1].len = 7;

		@@ -231,9 +298,186 @@ static int ds1307_set_time(struct device dev, struct rtc_time t)
		return 0;
		}

		static int ds1307_read_alarm(struct device dev, struct rtc_wkalrm t)
		{
		struct i2c_client *client = to_i2c_client(dev);
		struct ds1307 *ds1307 = i2c_get_clientdata(client);
		int ret;

		if (!test_bit(HAS_ALARM, &ds1307->flags))
		return -EINVAL;

		/* read all ALARM1, ALARM2, and status registers at once */
		ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
		ds1307->msg[1].flags = I2C_M_RD;
		ds1307->msg[1].len = 9;

		ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
		ds1307->msg, 2);
		if (ret != 2) {
		dev_err(dev, "%s error %d\n", "alarm read", ret);
		return -EIO;
		}

		dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
		"alarm read",
		ds1307->regs[0], ds1307->regs[1],
		ds1307->regs[2], ds1307->regs[3],
		ds1307->regs[4], ds1307->regs[5],
		ds1307->regs[6], ds1307->regs[7],
		ds1307->regs[8]);

		/* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
		* and that all four fields are checked matches
		*/
		t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
		t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
		t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
		t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
		t->time.tm_mon = -1;
		t->time.tm_year = -1;
		t->time.tm_wday = -1;
		t->time.tm_yday = -1;
		t->time.tm_isdst = -1;

		/* ... and status */
		t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
		t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);

		dev_dbg(dev, "%s secs=%d, mins=%d, "
		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
		"alarm read", t->time.tm_sec, t->time.tm_min,
		t->time.tm_hour, t->time.tm_mday,
		t->enabled, t->pending);

		return 0;
		}

		static int ds1307_set_alarm(struct device dev, struct rtc_wkalrm t)
		{
		struct i2c_client *client = to_i2c_client(dev);
		struct ds1307 *ds1307 = i2c_get_clientdata(client);
		unsigned char *buf = ds1307->regs;
		u8 control, status;
		int ret;

		if (!test_bit(HAS_ALARM, &ds1307->flags))
		return -EINVAL;

		dev_dbg(dev, "%s secs=%d, mins=%d, "
		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
		"alarm set", t->time.tm_sec, t->time.tm_min,
		t->time.tm_hour, t->time.tm_mday,
		t->enabled, t->pending);

		/* read current status of both alarms and the chip */
		ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
		ds1307->msg[1].flags = I2C_M_RD;
		ds1307->msg[1].len = 9;

		ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
		ds1307->msg, 2);
		if (ret != 2) {
		dev_err(dev, "%s error %d\n", "alarm write", ret);
		return -EIO;
		}
		control = ds1307->regs[7];
		status = ds1307->regs[8];

		dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
		"alarm set (old status)",
		ds1307->regs[0], ds1307->regs[1],
		ds1307->regs[2], ds1307->regs[3],
		ds1307->regs[4], ds1307->regs[5],
		ds1307->regs[6], control, status);

		/* set ALARM1, using 24 hour and day-of-month modes */
		buf++ = DS1339_REG_ALARM1_SECS; / first register addr */
		buf[0] = bin2bcd(t->time.tm_sec);
		buf[1] = bin2bcd(t->time.tm_min);
		buf[2] = bin2bcd(t->time.tm_hour);
		buf[3] = bin2bcd(t->time.tm_mday);

		/* set ALARM2 to non-garbage */
		buf[4] = 0;
		buf[5] = 0;
		buf[6] = 0;

		/* optionally enable ALARM1 */
		buf[7] = control & ~(DS1337_BIT_A1IE \| DS1337_BIT_A2IE);
		if (t->enabled) {
		dev_dbg(dev, "alarm IRQ armed\n");
		buf[7] \|= DS1337_BIT_A1IE; /* only ALARM1 is used */
		}
		buf[8] = status & ~(DS1337_BIT_A1I \| DS1337_BIT_A2I);

		ds1307->msg[1].flags = 0;
		ds1307->msg[1].len = 10;

		ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
		&ds1307->msg[1], 1);
		if (ret != 1) {
		dev_err(dev, "can't set alarm time\n");
		return -EIO;
		}

		return 0;
		}

		static int ds1307_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
		{
		struct i2c_client *client = to_i2c_client(dev);
		struct ds1307 *ds1307 = i2c_get_clientdata(client);
		int ret;

		switch (cmd) {
		case RTC_AIE_OFF:
		if (!test_bit(HAS_ALARM, &ds1307->flags))
		return -ENOTTY;

		ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
		if (ret < 0)
		return ret;

		ret &= ~DS1337_BIT_A1IE;

		ret = i2c_smbus_write_byte_data(client,
		DS1337_REG_CONTROL, ret);
		if (ret < 0)
		return ret;

		break;

		case RTC_AIE_ON:
		if (!test_bit(HAS_ALARM, &ds1307->flags))
		return -ENOTTY;

		ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
		if (ret < 0)
		return ret;

		ret \|= DS1337_BIT_A1IE;

		ret = i2c_smbus_write_byte_data(client,
		DS1337_REG_CONTROL, ret);
		if (ret < 0)
		return ret;

		break;

		default:
		return -ENOIOCTLCMD;
		}

		return 0;
		}

		static const struct rtc_class_ops ds13xx_rtc_ops = {
		.read_time = ds1307_get_time,
		.set_time = ds1307_set_time,
		.read_alarm = ds1307_read_alarm,
		.set_alarm = ds1307_set_alarm,
		.ioctl = ds1307_ioctl,
		};

		/----------------------------------------------------------------------/
		@@ -327,6 +571,7 @@ static int __devinit ds1307_probe(struct i2c_client *client,
		int tmp;
		const struct chip_desc *chip = &chips[id->driver_data];
		struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
		int want_irq = false;

		if (!i2c_check_functionality(adapter,
		I2C_FUNC_I2C \| I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
		@@ -353,6 +598,12 @@ static int __devinit ds1307_probe(struct i2c_client *client,
		switch (ds1307->type) {
		case ds_1337:
		case ds_1339:
		/* has IRQ? */
		if (ds1307->client->irq > 0 && chip->alarm) {
		INIT_WORK(&ds1307->work, ds1307_work);
		want_irq = true;
		}

		ds1307->reg_addr = DS1337_REG_CONTROL;
		ds1307->msg[1].len = 2;

		@@ -369,8 +620,20 @@ static int __devinit ds1307_probe(struct i2c_client *client,

		/* oscillator off? turn it on, so clock can tick. */
		if (ds1307->regs[0] & DS1337_BIT_nEOSC)
		ds1307->regs[0] &= ~DS1337_BIT_nEOSC;

		/* Using IRQ? Disable the square wave and both alarms.
		* For ds1339, be sure alarms can trigger when we're
		* running on Vbackup (BBSQI); we assume ds1337 will
		* ignore that bit
		*/
		if (want_irq) {
		ds1307->regs[0] \|= DS1337_BIT_INTCN \| DS1339_BIT_BBSQI;
		ds1307->regs[0] &= ~(DS1337_BIT_A2IE \| DS1337_BIT_A1IE);
		}

		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
		ds1307->regs[0] & ~DS1337_BIT_nEOSC);
		ds1307->regs[0]);

		/* oscillator fault? clear flag, and warn */
		if (ds1307->regs[1] & DS1337_BIT_OSF) {
		@@ -495,10 +758,22 @@ static int __devinit ds1307_probe(struct i2c_client *client,
		goto exit_free;
		}

		if (want_irq) {
		err = request_irq(client->irq, ds1307_irq, 0,
		ds1307->rtc->name, client);
		if (err) {
		dev_err(&client->dev,
		"unable to request IRQ!\n");
		goto exit_irq;
		}
		set_bit(HAS_ALARM, &ds1307->flags);
		dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
		}

		if (chip->nvram56) {
		err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
		if (err == 0) {
		ds1307->has_nvram = true;
		set_bit(HAS_NVRAM, &ds1307->flags);
		dev_info(&client->dev, "56 bytes nvram\n");
		}
		}
		@@ -512,7 +787,9 @@ static int __devinit ds1307_probe(struct i2c_client *client,
		ds1307->regs[2], ds1307->regs[3],
		ds1307->regs[4], ds1307->regs[5],
		ds1307->regs[6]);

		exit_irq:
		if (ds1307->rtc)
		rtc_device_unregister(ds1307->rtc);
		exit_free:
		kfree(ds1307);
		return err;
		@@ -522,7 +799,12 @@ static int __devexit ds1307_remove(struct i2c_client *client)
		{
		struct ds1307 *ds1307 = i2c_get_clientdata(client);

		if (ds1307->has_nvram)
		if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
		free_irq(client->irq, client);
		cancel_work_sync(&ds1307->work);
		}

		if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
		sysfs_remove_bin_file(&client->dev.kobj, &nvram);

		rtc_device_unregister(ds1307->rtc);