drivers/rtc/rtc-abx80x.c - kernel/msm-4.9 - Gitiles

 /*
  * A driver for the I2C members of the Abracon AB x8xx RTC family,
  * and compatible: AB 1805 and AB 0805
  *
  * Copyright 2014-2015 Macq S.A.
  *
  * Author: Philippe De Muyter <phdm@macqel.be>
  * Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
  *
  * 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/i2c.h>
 #include <linux/module.h>
 #include <linux/rtc.h>

 #define ABX8XX_REG_HTH		0x00
 #define ABX8XX_REG_SC		0x01
 #define ABX8XX_REG_MN		0x02
 #define ABX8XX_REG_HR		0x03
 #define ABX8XX_REG_DA		0x04
 #define ABX8XX_REG_MO		0x05
 #define ABX8XX_REG_YR		0x06
 #define ABX8XX_REG_WD		0x07

 #define ABX8XX_REG_CTRL1	0x10
 #define ABX8XX_CTRL_WRITE	BIT(1)
 #define ABX8XX_CTRL_12_24	BIT(6)

 #define ABX8XX_REG_CFG_KEY	0x1f
 #define ABX8XX_CFG_KEY_MISC	0x9d

 #define ABX8XX_REG_ID0		0x28

 #define ABX8XX_REG_TRICKLE	0x20
 #define ABX8XX_TRICKLE_CHARGE_ENABLE	0xa0
 #define ABX8XX_TRICKLE_STANDARD_DIODE	0x8
 #define ABX8XX_TRICKLE_SCHOTTKY_DIODE	0x4

 static u8 trickle_resistors[] = {0, 3, 6, 11};

 enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
 	AB1801, AB1803, AB1804, AB1805, ABX80X};

 struct abx80x_cap {
 	u16 pn;
 	bool has_tc;
 };

 static struct abx80x_cap abx80x_caps[] = {
 	[AB0801] = {.pn = 0x0801},
 	[AB0803] = {.pn = 0x0803},
 	[AB0804] = {.pn = 0x0804, .has_tc = true},
 	[AB0805] = {.pn = 0x0805, .has_tc = true},
 	[AB1801] = {.pn = 0x1801},
 	[AB1803] = {.pn = 0x1803},
 	[AB1804] = {.pn = 0x1804, .has_tc = true},
 	[AB1805] = {.pn = 0x1805, .has_tc = true},
 	[ABX80X] = {.pn = 0}
 };

 static struct i2c_driver abx80x_driver;

 static int abx80x_enable_trickle_charger(struct i2c_client *client,
 					 u8 trickle_cfg)
 {
 	int err;

 	/*
 	 * Write the configuration key register to enable access to the Trickle
 	 * register
 	 */
 	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
 					ABX8XX_CFG_KEY_MISC);
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to write configuration key\n");
 		return -EIO;
 	}

 	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
 					ABX8XX_TRICKLE_CHARGE_ENABLE |
 					trickle_cfg);
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to write trickle register\n");
 		return -EIO;
 	}

 	return 0;
 }

 static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	unsigned char buf[8];
 	int err;

 	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
 					    sizeof(buf), buf);
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to read date\n");
 		return -EIO;
 	}

 	tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
 	tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
 	tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
 	tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
 	tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
 	tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
 	tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;

 	err = rtc_valid_tm(tm);
 	if (err < 0)
 		dev_err(&client->dev, "retrieved date/time is not valid.\n");

 	return err;
 }

 static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	unsigned char buf[8];
 	int err;

 	if (tm->tm_year < 100)
 		return -EINVAL;

 	buf[ABX8XX_REG_HTH] = 0;
 	buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
 	buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
 	buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
 	buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
 	buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
 	buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
 	buf[ABX8XX_REG_WD] = tm->tm_wday;

 	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
 					     sizeof(buf), buf);
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to write to date registers\n");
 		return -EIO;
 	}

 	return 0;
 }

 static const struct rtc_class_ops abx80x_rtc_ops = {
 	.read_time	= abx80x_rtc_read_time,
 	.set_time	= abx80x_rtc_set_time,
 };

 static int abx80x_dt_trickle_cfg(struct device_node *np)
 {
 	const char *diode;
 	int trickle_cfg = 0;
 	int i, ret;
 	u32 tmp;

 	ret = of_property_read_string(np, "abracon,tc-diode", &diode);
 	if (ret)
 		return ret;

 	if (!strcmp(diode, "standard"))
 		trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
 	else if (!strcmp(diode, "schottky"))
 		trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
 	else
 		return -EINVAL;

 	ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
 	if (ret)
 		return ret;

 	for (i = 0; i < sizeof(trickle_resistors); i++)
 		if (trickle_resistors[i] == tmp)
 			break;

 	if (i == sizeof(trickle_resistors))
 		return -EINVAL;

 	return (trickle_cfg | i);
 }

 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;
 	int i, data, err, trickle_cfg = -EINVAL;
 	char buf[7];
 	unsigned int part = id->driver_data;
 	unsigned int partnumber;
 	unsigned int majrev, minrev;
 	unsigned int lot;
 	unsigned int wafer;
 	unsigned int uid;

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return -ENODEV;

 	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
 					    sizeof(buf), buf);
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to read partnumber\n");
 		return -EIO;
 	}

 	partnumber = (buf[0] << 8) | buf[1];
 	majrev = buf[2] >> 3;
 	minrev = buf[2] & 0x7;
 	lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
 	uid = ((buf[4] & 0x7f) << 8) | buf[5];
 	wafer = (buf[6] & 0x7c) >> 2;
 	dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
 		 partnumber, majrev, minrev, lot, wafer, uid);

 	data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
 	if (data < 0) {
 		dev_err(&client->dev, "Unable to read control register\n");
 		return -EIO;
 	}

 	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
 					((data & ~ABX8XX_CTRL_12_24) |
 					 ABX8XX_CTRL_WRITE));
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to write control register\n");
 		return -EIO;
 	}

 	/* part autodetection */
 	if (part == ABX80X) {
 		for (i = 0; abx80x_caps[i].pn; i++)
 			if (partnumber == abx80x_caps[i].pn)
 				break;
 		if (abx80x_caps[i].pn == 0) {
 			dev_err(&client->dev, "Unknown part: %04x\n",
 				partnumber);
 			return -EINVAL;
 		}
 		part = i;
 	}

 	if (partnumber != abx80x_caps[part].pn) {
 		dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
 			partnumber, abx80x_caps[part].pn);
 		return -EINVAL;
 	}

 	if (np && abx80x_caps[part].has_tc)
 		trickle_cfg = abx80x_dt_trickle_cfg(np);

 	if (trickle_cfg > 0) {
 		dev_info(&client->dev, "Enabling trickle charger: %02x\n",
 			 trickle_cfg);
 		abx80x_enable_trickle_charger(client, trickle_cfg);
 	}

 	rtc = devm_rtc_device_register(&client->dev, abx80x_driver.driver.name,
 				       &abx80x_rtc_ops, THIS_MODULE);

 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);

 	i2c_set_clientdata(client, rtc);

 	return 0;
 }

 static int abx80x_remove(struct i2c_client *client)
 {
 	return 0;
 }

 static const struct i2c_device_id abx80x_id[] = {
 	{ "abx80x", ABX80X },
 	{ "ab0801", AB0801 },
 	{ "ab0803", AB0803 },
 	{ "ab0804", AB0804 },
 	{ "ab0805", AB0805 },
 	{ "ab1801", AB1801 },
 	{ "ab1803", AB1803 },
 	{ "ab1804", AB1804 },
 	{ "ab1805", AB1805 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, abx80x_id);

 static struct i2c_driver abx80x_driver = {
 	.driver		= {
 		.name	= "rtc-abx80x",
 	},
 	.probe		= abx80x_probe,
 	.remove		= abx80x_remove,
 	.id_table	= abx80x_id,
 };

 module_i2c_driver(abx80x_driver);

 MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
 MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
 MODULE_LICENSE("GPL v2");
	/*
	* A driver for the I2C members of the Abracon AB x8xx RTC family,
	* and compatible: AB 1805 and AB 0805
	*
	* Copyright 2014-2015 Macq S.A.
	*
	* Author: Philippe De Muyter <phdm@macqel.be>
	* Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
	*
	* 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/i2c.h>
	#include <linux/module.h>
	#include <linux/rtc.h>

	#define ABX8XX_REG_HTH 0x00
	#define ABX8XX_REG_SC 0x01
	#define ABX8XX_REG_MN 0x02
	#define ABX8XX_REG_HR 0x03
	#define ABX8XX_REG_DA 0x04
	#define ABX8XX_REG_MO 0x05
	#define ABX8XX_REG_YR 0x06
	#define ABX8XX_REG_WD 0x07

	#define ABX8XX_REG_CTRL1 0x10
	#define ABX8XX_CTRL_WRITE BIT(1)
	#define ABX8XX_CTRL_12_24 BIT(6)

	#define ABX8XX_REG_CFG_KEY 0x1f
	#define ABX8XX_CFG_KEY_MISC 0x9d

	#define ABX8XX_REG_ID0 0x28

	#define ABX8XX_REG_TRICKLE 0x20
	#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
	#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
	#define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4

	static u8 trickle_resistors[] = {0, 3, 6, 11};

	enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
	AB1801, AB1803, AB1804, AB1805, ABX80X};

	struct abx80x_cap {
	u16 pn;
	bool has_tc;
	};

	static struct abx80x_cap abx80x_caps[] = {
	[AB0801] = {.pn = 0x0801},
	[AB0803] = {.pn = 0x0803},
	[AB0804] = {.pn = 0x0804, .has_tc = true},
	[AB0805] = {.pn = 0x0805, .has_tc = true},
	[AB1801] = {.pn = 0x1801},
	[AB1803] = {.pn = 0x1803},
	[AB1804] = {.pn = 0x1804, .has_tc = true},
	[AB1805] = {.pn = 0x1805, .has_tc = true},
	[ABX80X] = {.pn = 0}
	};

	static struct i2c_driver abx80x_driver;

	static int abx80x_enable_trickle_charger(struct i2c_client *client,
	u8 trickle_cfg)
	{
	int err;

	/*
	* Write the configuration key register to enable access to the Trickle
	* register
	*/
	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
	ABX8XX_CFG_KEY_MISC);
	if (err < 0) {
	dev_err(&client->dev, "Unable to write configuration key\n");
	return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
	ABX8XX_TRICKLE_CHARGE_ENABLE \|
	trickle_cfg);
	if (err < 0) {
	dev_err(&client->dev, "Unable to write trickle register\n");
	return -EIO;
	}

	return 0;
	}

	static int abx80x_rtc_read_time(struct device dev, struct rtc_time tm)
	{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf[8];
	int err;

	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
	sizeof(buf), buf);
	if (err < 0) {
	dev_err(&client->dev, "Unable to read date\n");
	return -EIO;
	}

	tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
	tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
	tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
	tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
	tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;

	err = rtc_valid_tm(tm);
	if (err < 0)
	dev_err(&client->dev, "retrieved date/time is not valid.\n");

	return err;
	}

	static int abx80x_rtc_set_time(struct device dev, struct rtc_time tm)
	{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf[8];
	int err;

	if (tm->tm_year < 100)
	return -EINVAL;

	buf[ABX8XX_REG_HTH] = 0;
	buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
	buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
	buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
	buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
	buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
	buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
	buf[ABX8XX_REG_WD] = tm->tm_wday;

	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
	sizeof(buf), buf);
	if (err < 0) {
	dev_err(&client->dev, "Unable to write to date registers\n");
	return -EIO;
	}

	return 0;
	}

	static const struct rtc_class_ops abx80x_rtc_ops = {
	.read_time = abx80x_rtc_read_time,
	.set_time = abx80x_rtc_set_time,
	};

	static int abx80x_dt_trickle_cfg(struct device_node *np)
	{
	const char *diode;
	int trickle_cfg = 0;
	int i, ret;
	u32 tmp;

	ret = of_property_read_string(np, "abracon,tc-diode", &diode);
	if (ret)
	return ret;

	if (!strcmp(diode, "standard"))
	trickle_cfg \|= ABX8XX_TRICKLE_STANDARD_DIODE;
	else if (!strcmp(diode, "schottky"))
	trickle_cfg \|= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
	else
	return -EINVAL;

	ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
	if (ret)
	return ret;

	for (i = 0; i < sizeof(trickle_resistors); i++)
	if (trickle_resistors[i] == tmp)
	break;

	if (i == sizeof(trickle_resistors))
	return -EINVAL;

	return (trickle_cfg \| i);
	}

	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;
	int i, data, err, trickle_cfg = -EINVAL;
	char buf[7];
	unsigned int part = id->driver_data;
	unsigned int partnumber;
	unsigned int majrev, minrev;
	unsigned int lot;
	unsigned int wafer;
	unsigned int uid;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	return -ENODEV;

	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
	sizeof(buf), buf);
	if (err < 0) {
	dev_err(&client->dev, "Unable to read partnumber\n");
	return -EIO;
	}

	partnumber = (buf[0] << 8) \| buf[1];
	majrev = buf[2] >> 3;
	minrev = buf[2] & 0x7;
	lot = ((buf[4] & 0x80) << 2) \| ((buf[6] & 0x80) << 1) \| buf[3];
	uid = ((buf[4] & 0x7f) << 8) \| buf[5];
	wafer = (buf[6] & 0x7c) >> 2;
	dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
	partnumber, majrev, minrev, lot, wafer, uid);

	data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
	if (data < 0) {
	dev_err(&client->dev, "Unable to read control register\n");
	return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
	((data & ~ABX8XX_CTRL_12_24) \|
	ABX8XX_CTRL_WRITE));
	if (err < 0) {
	dev_err(&client->dev, "Unable to write control register\n");
	return -EIO;
	}

	/* part autodetection */
	if (part == ABX80X) {
	for (i = 0; abx80x_caps[i].pn; i++)
	if (partnumber == abx80x_caps[i].pn)
	break;
	if (abx80x_caps[i].pn == 0) {
	dev_err(&client->dev, "Unknown part: %04x\n",
	partnumber);
	return -EINVAL;
	}
	part = i;
	}

	if (partnumber != abx80x_caps[part].pn) {
	dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
	partnumber, abx80x_caps[part].pn);
	return -EINVAL;
	}

	if (np && abx80x_caps[part].has_tc)
	trickle_cfg = abx80x_dt_trickle_cfg(np);

	if (trickle_cfg > 0) {
	dev_info(&client->dev, "Enabling trickle charger: %02x\n",
	trickle_cfg);
	abx80x_enable_trickle_charger(client, trickle_cfg);
	}

	rtc = devm_rtc_device_register(&client->dev, abx80x_driver.driver.name,
	&abx80x_rtc_ops, THIS_MODULE);

	if (IS_ERR(rtc))
	return PTR_ERR(rtc);

	i2c_set_clientdata(client, rtc);

	return 0;
	}

	static int abx80x_remove(struct i2c_client *client)
	{
	return 0;
	}

	static const struct i2c_device_id abx80x_id[] = {
	{ "abx80x", ABX80X },
	{ "ab0801", AB0801 },
	{ "ab0803", AB0803 },
	{ "ab0804", AB0804 },
	{ "ab0805", AB0805 },
	{ "ab1801", AB1801 },
	{ "ab1803", AB1803 },
	{ "ab1804", AB1804 },
	{ "ab1805", AB1805 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, abx80x_id);

	static struct i2c_driver abx80x_driver = {
	.driver = {
	.name = "rtc-abx80x",
	},
	.probe = abx80x_probe,
	.remove = abx80x_remove,
	.id_table = abx80x_id,
	};

	module_i2c_driver(abx80x_driver);

	MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
	MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
	MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
	MODULE_LICENSE("GPL v2");