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Commit ed13d89b authored by Akshay Bhat's avatar Akshay Bhat Committed by Alexandre Belloni
Browse files

rtc: Add Epson RX8010SJ RTC driver 

This driver supports the following functions:
 - reading and setting time
 - alarms when connected to an IRQ
 - reading and clearing the voltage low flags

Datasheet:
http://www.epsondevice.com/docs/qd/en/DownloadServlet?id=ID000956


Signed-off-by: default avatarAkshay Bhat <akshay.bhat@timesys.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
parent 529af7d1

drivers/rtc/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -558,6 +558,16 @@ config RTC_DRV_FM3130 
	  This driver can also be built as a module. If so the module

	  will be called rtc-fm3130.



config RTC_DRV_RX8010

	tristate "Epson RX8010SJ"

	depends on I2C

	help

	  If you say yes here you get support for the Epson RX8010SJ RTC

	  chip.



	  This driver can also be built as a module. If so, the module

	  will be called rtc-rx8010.



config RTC_DRV_RX8581

	tristate "Epson RX-8581"

	help

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o 
obj-$(CONFIG_RTC_DRV_RV3029C2)	+= rtc-rv3029c2.o

obj-$(CONFIG_RTC_DRV_RV8803)	+= rtc-rv8803.o

obj-$(CONFIG_RTC_DRV_RX4581)	+= rtc-rx4581.o

obj-$(CONFIG_RTC_DRV_RX8010)	+= rtc-rx8010.o

obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o

obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o

obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o

drivers/rtc/rtc-rx8010.c

0 → 100644
+523 −0
Original line number Diff line number Diff line 
/*

 * Driver for the Epson RTC module RX-8010 SJ

 *

 * Copyright(C) Timesys Corporation 2015

 * Copyright(C) General Electric Company 2015

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 */



#include <linux/bcd.h>

#include <linux/bitops.h>

#include <linux/i2c.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/rtc.h>



#define RX8010_SEC     0x10

#define RX8010_MIN     0x11

#define RX8010_HOUR    0x12

#define RX8010_WDAY    0x13

#define RX8010_MDAY    0x14

#define RX8010_MONTH   0x15

#define RX8010_YEAR    0x16

#define RX8010_YEAR    0x16

#define RX8010_RESV17  0x17

#define RX8010_ALMIN   0x18

#define RX8010_ALHOUR  0x19

#define RX8010_ALWDAY  0x1A

#define RX8010_TCOUNT0 0x1B

#define RX8010_TCOUNT1 0x1C

#define RX8010_EXT     0x1D

#define RX8010_FLAG    0x1E

#define RX8010_CTRL    0x1F

/* 0x20 to 0x2F are user registers */

#define RX8010_RESV30  0x30

#define RX8010_RESV31  0x32

#define RX8010_IRQ     0x32



#define RX8010_EXT_WADA  BIT(3)



#define RX8010_FLAG_VLF  BIT(1)

#define RX8010_FLAG_AF   BIT(3)

#define RX8010_FLAG_TF   BIT(4)

#define RX8010_FLAG_UF   BIT(5)



#define RX8010_CTRL_AIE  BIT(3)

#define RX8010_CTRL_UIE  BIT(5)

#define RX8010_CTRL_STOP BIT(6)

#define RX8010_CTRL_TEST BIT(7)



#define RX8010_ALARM_AE  BIT(7)



static const struct i2c_device_id rx8010_id[] = {

	{ "rx8010", 0 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, rx8010_id);



struct rx8010_data {

	struct i2c_client *client;

	struct rtc_device *rtc;

	u8 ctrlreg;

	spinlock_t flags_lock;

};



static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)

{

	struct i2c_client *client = dev_id;

	struct rx8010_data *rx8010 = i2c_get_clientdata(client);

	int flagreg;



	spin_lock(&rx8010->flags_lock);



	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);



	if (flagreg <= 0) {

		spin_unlock(&rx8010->flags_lock);

		return IRQ_NONE;

	}



	if (flagreg & RX8010_FLAG_VLF)

		dev_warn(&client->dev, "Frequency stop detected\n");



	if (flagreg & RX8010_FLAG_TF) {

		flagreg &= ~RX8010_FLAG_TF;

		rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);

	}



	if (flagreg & RX8010_FLAG_AF) {

		flagreg &= ~RX8010_FLAG_AF;

		rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);

	}



	if (flagreg & RX8010_FLAG_UF) {

		flagreg &= ~RX8010_FLAG_UF;

		rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);

	}



	i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);



	spin_unlock(&rx8010->flags_lock);

	return IRQ_HANDLED;

}



static int rx8010_get_time(struct device *dev, struct rtc_time *dt)

{

	struct rx8010_data *rx8010 = dev_get_drvdata(dev);

	u8 date[7];

	int flagreg;

	int err;



	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);

	if (flagreg < 0)

		return flagreg;



	if (flagreg & RX8010_FLAG_VLF) {

		dev_warn(dev, "Frequency stop detected\n");

		return -EINVAL;

	}



	err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC,

					    7, date);

	if (err != 7)

		return err < 0 ? err : -EIO;



	dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);

	dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);

	dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);

	dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);

	dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;

	dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;

	dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);



	return rtc_valid_tm(dt);

}



static int rx8010_set_time(struct device *dev, struct rtc_time *dt)

{

	struct rx8010_data *rx8010 = dev_get_drvdata(dev);

	u8 date[7];

	int ctrl, flagreg;

	int ret;

	unsigned long irqflags;



	if ((dt->tm_year < 100) || (dt->tm_year > 199))

		return -EINVAL;



	/* set STOP bit before changing clock/calendar */

	ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);

	if (ctrl < 0)

		return ctrl;

	rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;

	ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,

					rx8010->ctrlreg);

	if (ret < 0)

		return ret;



	date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);

	date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);

	date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);

	date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);

	date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);

	date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);

	date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);



	ret = i2c_smbus_write_i2c_block_data(rx8010->client,

					     RX8010_SEC, 7, date);

	if (ret < 0)

		return ret;



	/* clear STOP bit after changing clock/calendar */

	ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);

	if (ctrl < 0)

		return ctrl;

	rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;

	ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,

					rx8010->ctrlreg);

	if (ret < 0)

		return ret;



	spin_lock_irqsave(&rx8010->flags_lock, irqflags);



	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);

	if (flagreg < 0) {

		spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);

		return flagreg;

	}



	if (flagreg & RX8010_FLAG_VLF)

		ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,

						flagreg & ~RX8010_FLAG_VLF);



	spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);



	return 0;

}



static int rx8010_init_client(struct i2c_client *client)

{

	struct rx8010_data *rx8010 = i2c_get_clientdata(client);

	u8 ctrl[2];

	int need_clear = 0, err = 0;



	/* Initialize reserved registers as specified in datasheet */

	err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);

	if (err < 0)

		return err;



	err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);

	if (err < 0)

		return err;



	err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);

	if (err < 0)

		return err;



	err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);

	if (err < 0)

		return err;



	err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG,

					    2, ctrl);

	if (err != 2)

		return err < 0 ? err : -EIO;



	if (ctrl[0] & RX8010_FLAG_VLF)

		dev_warn(&client->dev, "Frequency stop was detected\n");



	if (ctrl[0] & RX8010_FLAG_AF) {

		dev_warn(&client->dev, "Alarm was detected\n");

		need_clear = 1;

	}



	if (ctrl[0] & RX8010_FLAG_TF)

		need_clear = 1;



	if (ctrl[0] & RX8010_FLAG_UF)

		need_clear = 1;



	if (need_clear) {

		ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);

		err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]);

		if (err < 0)

			return err;

	}



	rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);



	return err;

}



static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)

{

	struct rx8010_data *rx8010 = dev_get_drvdata(dev);

	struct i2c_client *client = rx8010->client;

	u8 alarmvals[3];

	int flagreg;

	int err;



	err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals);

	if (err != 3)

		return err < 0 ? err : -EIO;



	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);

	if (flagreg < 0)

		return flagreg;



	t->time.tm_sec = 0;

	t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);

	t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);



	if (alarmvals[2] & RX8010_ALARM_AE)

		t->time.tm_mday = -1;

	else

		t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);



	t->time.tm_wday = -1;

	t->time.tm_mon = -1;

	t->time.tm_year = -1;



	t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);

	t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;



	return err;

}



static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct rx8010_data *rx8010 = dev_get_drvdata(dev);

	u8 alarmvals[3];

	int extreg, flagreg;

	int err;

	unsigned long irqflags;



	spin_lock_irqsave(&rx8010->flags_lock, irqflags);

	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);

	if (flagreg < 0) {

		spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);

		return flagreg;

	}



	if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {

		rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);

		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,

						rx8010->ctrlreg);

		if (err < 0) {

			spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);

			return err;

		}

	}



	flagreg &= ~RX8010_FLAG_AF;

	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);

	spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);

	if (err < 0)

		return err;



	alarmvals[0] = bin2bcd(t->time.tm_min);

	alarmvals[1] = bin2bcd(t->time.tm_hour);

	alarmvals[2] = bin2bcd(t->time.tm_mday);



	err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,

					     2, alarmvals);

	if (err < 0)

		return err;



	extreg = i2c_smbus_read_byte_data(client, RX8010_EXT);

	if (extreg < 0)

		return extreg;



	extreg |= RX8010_EXT_WADA;

	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);

	if (err < 0)

		return err;



	if (alarmvals[2] == 0)

		alarmvals[2] |= RX8010_ALARM_AE;



	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,

					alarmvals[2]);

	if (err < 0)

		return err;



	if (t->enabled) {

		if (rx8010->rtc->uie_rtctimer.enabled)

			rx8010->ctrlreg |= RX8010_CTRL_UIE;

		if (rx8010->rtc->aie_timer.enabled)

			rx8010->ctrlreg |=

				(RX8010_CTRL_AIE | RX8010_CTRL_UIE);



		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,

						rx8010->ctrlreg);

		if (err < 0)

			return err;

	}



	return 0;

}



static int rx8010_alarm_irq_enable(struct device *dev,

				   unsigned int enabled)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct rx8010_data *rx8010 = dev_get_drvdata(dev);

	int flagreg;

	u8 ctrl;

	int err;



	ctrl = rx8010->ctrlreg;



	if (enabled) {

		if (rx8010->rtc->uie_rtctimer.enabled)

			ctrl |= RX8010_CTRL_UIE;

		if (rx8010->rtc->aie_timer.enabled)

			ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);

	} else {

		if (!rx8010->rtc->uie_rtctimer.enabled)

			ctrl &= ~RX8010_CTRL_UIE;

		if (!rx8010->rtc->aie_timer.enabled)

			ctrl &= ~RX8010_CTRL_AIE;

	}



	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);

	if (flagreg < 0)

		return flagreg;



	flagreg &= ~RX8010_FLAG_AF;

	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);

	if (err < 0)

		return err;



	if (ctrl != rx8010->ctrlreg) {

		rx8010->ctrlreg = ctrl;

		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,

						rx8010->ctrlreg);

		if (err < 0)

			return err;

	}



	return 0;

}



static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct rx8010_data *rx8010 = dev_get_drvdata(dev);

	int ret, tmp;

	int flagreg;

	unsigned long irqflags;



	switch (cmd) {

	case RTC_VL_READ:

		flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);

		if (flagreg < 0)

			return flagreg;



		tmp = !!(flagreg & RX8010_FLAG_VLF);

		if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))

			return -EFAULT;



		return 0;



	case RTC_VL_CLR:

		spin_lock_irqsave(&rx8010->flags_lock, irqflags);

		flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);

		if (flagreg < 0) {

			spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);

			return flagreg;

		}



		flagreg &= ~RX8010_FLAG_VLF;

		ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);

		spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);

		if (ret < 0)

			return ret;



		return 0;



	default:

		return -ENOIOCTLCMD;

	}

}



static struct rtc_class_ops rx8010_rtc_ops = {

	.read_time = rx8010_get_time,

	.set_time = rx8010_set_time,

	.ioctl = rx8010_ioctl,

};



static int rx8010_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{

	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);

	struct rx8010_data *rx8010;

	int err = 0;



	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA

		| I2C_FUNC_SMBUS_I2C_BLOCK)) {

		dev_err(&adapter->dev, "doesn't support required functionality\n");

		return -EIO;

	}



	rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),

			      GFP_KERNEL);

	if (!rx8010)

		return -ENOMEM;



	rx8010->client = client;

	i2c_set_clientdata(client, rx8010);



	spin_lock_init(&rx8010->flags_lock);



	err = rx8010_init_client(client);

	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,

						rx8010_irq_1_handler,

						IRQF_TRIGGER_LOW | IRQF_ONESHOT,

						"rx8010", client);



		if (err) {

			dev_err(&client->dev, "unable to request IRQ\n");

			client->irq = 0;

		} else {

			rx8010_rtc_ops.read_alarm = rx8010_read_alarm;

			rx8010_rtc_ops.set_alarm = rx8010_set_alarm;

			rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable;

		}

	}



	rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,

		&rx8010_rtc_ops, THIS_MODULE);



	if (IS_ERR(rx8010->rtc)) {

		dev_err(&client->dev, "unable to register the class device\n");

		return PTR_ERR(rx8010->rtc);

	}



	rx8010->rtc->max_user_freq = 1;



	return err;

}



static struct i2c_driver rx8010_driver = {

	.driver = {

		.name = "rtc-rx8010",

	},

	.probe		= rx8010_probe,

	.id_table	= rx8010_id,

};



module_i2c_driver(rx8010_driver);



MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");

MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");

MODULE_LICENSE("GPL v2");