[linux.git] / drivers / rtc / rtc-isl12022.c

/*
 * An I2C driver for the Intersil ISL 12022
 *
 * Author: Roman Fietze <[email protected]>
 *
 * Based on the Philips PCF8563 RTC
 * by Alessandro Zummo <[email protected]>.
 *
 * 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/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_device.h>

/* ISL register offsets */
#define ISL12022_REG_SC		0x00
#define ISL12022_REG_MN		0x01
#define ISL12022_REG_HR		0x02
#define ISL12022_REG_DT		0x03
#define ISL12022_REG_MO		0x04
#define ISL12022_REG_YR		0x05
#define ISL12022_REG_DW		0x06

#define ISL12022_REG_SR		0x07
#define ISL12022_REG_INT	0x08

/* ISL register bits */
#define ISL12022_HR_MIL		(1 << 7)	/* military or 24 hour time */

#define ISL12022_SR_LBAT85	(1 << 2)
#define ISL12022_SR_LBAT75	(1 << 1)

#define ISL12022_INT_WRTC	(1 << 6)


static struct i2c_driver isl12022_driver;

struct isl12022 {
	struct rtc_device *rtc;

	bool write_enabled;	/* true if write enable is set */
};


static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
			      uint8_t *data, size_t n)
{
	struct i2c_msg msgs[] = {
		{
			.addr	= client->addr,
			.flags	= 0,
			.len	= 1,
			.buf	= data
		},		/* setup read ptr */
		{
			.addr	= client->addr,
			.flags	= I2C_M_RD,
			.len	= n,
			.buf	= data
		}
	};

	int ret;

	data[0] = reg;
	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret != ARRAY_SIZE(msgs)) {
		dev_err(&client->dev, "%s: read error, ret=%d\n",
			__func__, ret);
		return -EIO;
	}

	return 0;
}


static int isl12022_write_reg(struct i2c_client *client,
			      uint8_t reg, uint8_t val)
{
	uint8_t data[2] = { reg, val };
	int err;

	err = i2c_master_send(client, data, sizeof(data));
	if (err != sizeof(data)) {
		dev_err(&client->dev,
			"%s: err=%d addr=%02x, data=%02x\n",
			__func__, err, data[0], data[1]);
		return -EIO;
	}

	return 0;
}


/*
 * In the routines that deal directly with the isl12022 hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
 */
static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	uint8_t buf[ISL12022_REG_INT + 1];
	int ret;

	ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
	if (ret)
		return ret;

	if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
		dev_warn(&client->dev,
			 "voltage dropped below %u%%, "
			 "date and time is not reliable.\n",
			 buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
	}

	dev_dbg(&client->dev,
		"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
		"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
		"sr=%02x, int=%02x",
		__func__,
		buf[ISL12022_REG_SC],
		buf[ISL12022_REG_MN],
		buf[ISL12022_REG_HR],
		buf[ISL12022_REG_DT],
		buf[ISL12022_REG_MO],
		buf[ISL12022_REG_YR],
		buf[ISL12022_REG_DW],
		buf[ISL12022_REG_SR],
		buf[ISL12022_REG_INT]);

	tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
	tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
	tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
	tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
	tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;

	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	return 0;
}

static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct isl12022 *isl12022 = i2c_get_clientdata(client);
	size_t i;
	int ret;
	uint8_t buf[ISL12022_REG_DW + 1];

	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	if (!isl12022->write_enabled) {

		ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
		if (ret)
			return ret;

		/* Check if WRTC (write rtc enable) is set factory default is
		 * 0 (not set) */
		if (!(buf[0] & ISL12022_INT_WRTC)) {
			dev_info(&client->dev,
				 "init write enable and 24 hour format\n");

			/* Set the write enable bit. */
			ret = isl12022_write_reg(client,
						 ISL12022_REG_INT,
						 buf[0] | ISL12022_INT_WRTC);
			if (ret)
				return ret;

			/* Write to any RTC register to start RTC, we use the
			 * HR register, setting the MIL bit to use the 24 hour
			 * format. */
			ret = isl12022_read_regs(client, ISL12022_REG_HR,
						 buf, 1);
			if (ret)
				return ret;

			ret = isl12022_write_reg(client,
						 ISL12022_REG_HR,
						 buf[0] | ISL12022_HR_MIL);
			if (ret)
				return ret;
		}

		isl12022->write_enabled = true;
	}

	/* hours, minutes and seconds */
	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;

	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);

	/* month, 1 - 12 */
	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);

	/* year and century */
	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);

	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;

	/* write register's data */
	for (i = 0; i < ARRAY_SIZE(buf); i++) {
		ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
					 buf[ISL12022_REG_SC + i]);
		if (ret)
			return -EIO;
	}

	return 0;
}

static const struct rtc_class_ops isl12022_rtc_ops = {
	.read_time	= isl12022_rtc_read_time,
	.set_time	= isl12022_rtc_set_time,
};

static int isl12022_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct isl12022 *isl12022;

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

	isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
				GFP_KERNEL);
	if (!isl12022)
		return -ENOMEM;

	i2c_set_clientdata(client, isl12022);

	isl12022->rtc = devm_rtc_device_register(&client->dev,
					isl12022_driver.driver.name,
					&isl12022_rtc_ops, THIS_MODULE);
	return PTR_ERR_OR_ZERO(isl12022->rtc);
}

#ifdef CONFIG_OF
static const struct of_device_id isl12022_dt_match[] = {
	{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
	{ .compatible = "isil,isl12022" },
	{ },
};
MODULE_DEVICE_TABLE(of, isl12022_dt_match);
#endif

static const struct i2c_device_id isl12022_id[] = {
	{ "isl12022", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, isl12022_id);

static struct i2c_driver isl12022_driver = {
	.driver		= {
		.name	= "rtc-isl12022",
#ifdef CONFIG_OF
		.of_match_table = of_match_ptr(isl12022_dt_match),
#endif
	},
	.probe		= isl12022_probe,
	.id_table	= isl12022_id,
};

module_i2c_driver(isl12022_driver);

MODULE_AUTHOR("[email protected]");
MODULE_DESCRIPTION("ISL 12022 RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
d6c7428f RF	1	/*
	2	* An I2C driver for the Intersil ISL 12022
	3	*
	4	* Author: Roman Fietze <[email protected]>
	5	*
	6	* Based on the Philips PCF8563 RTC
	7	* by Alessandro Zummo <[email protected]>.
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License version
	11	* 2 as published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/i2c.h>
	15	#include <linux/bcd.h>
	16	#include <linux/rtc.h>
	17	#include <linux/slab.h>
2113852b	18	#include <linux/module.h>
17cc54b2	19	#include <linux/err.h>
db04d628 SL	20	#include <linux/of.h>
db04d628 SL	21	#include <linux/of_device.h>
d6c7428f	22
d6c7428f RF	23	/* ISL register offsets */
	24	#define ISL12022_REG_SC 0x00
	25	#define ISL12022_REG_MN 0x01
	26	#define ISL12022_REG_HR 0x02
	27	#define ISL12022_REG_DT 0x03
	28	#define ISL12022_REG_MO 0x04
	29	#define ISL12022_REG_YR 0x05
	30	#define ISL12022_REG_DW 0x06
	31
	32	#define ISL12022_REG_SR 0x07
	33	#define ISL12022_REG_INT 0x08
	34
	35	/* ISL register bits */
	36	#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
	37
	38	#define ISL12022_SR_LBAT85 (1 << 2)
	39	#define ISL12022_SR_LBAT75 (1 << 1)
	40
	41	#define ISL12022_INT_WRTC (1 << 6)
	42
	43
	44	static struct i2c_driver isl12022_driver;
	45
	46	struct isl12022 {
	47	struct rtc_device *rtc;
	48
	49	bool write_enabled; /* true if write enable is set */
	50	};
	51
	52
	53	static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
	54	uint8_t *data, size_t n)
	55	{
	56	struct i2c_msg msgs[] = {
	57	{
	58	.addr = client->addr,
	59	.flags = 0,
	60	.len = 1,
	61	.buf = data
	62	}, /* setup read ptr */
	63	{
	64	.addr = client->addr,
	65	.flags = I2C_M_RD,
	66	.len = n,
	67	.buf = data
	68	}
	69	};
	70
	71	int ret;
	72
	73	data[0] = reg;
	74	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	75	if (ret != ARRAY_SIZE(msgs)) {
	76	dev_err(&client->dev, "%s: read error, ret=%d\n",
	77	__func__, ret);
	78	return -EIO;
	79	}
	80
	81	return 0;
	82	}
	83
	84
	85	static int isl12022_write_reg(struct i2c_client *client,
	86	uint8_t reg, uint8_t val)
87	{
88	uint8_t data[2] = { reg, val };
89	int err;
90
91	err = i2c_master_send(client, data, sizeof(data));
92	if (err != sizeof(data)) {
93	dev_err(&client->dev,
94	"%s: err=%d addr=%02x, data=%02x\n",
95	__func__, err, data[0], data[1]);
96	return -EIO;
97	}
98
99	return 0;
100	}
101
102
103	/*
104	* In the routines that deal directly with the isl12022 hardware, we use
105	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
106	*/
143d92be	107	static int isl12022_rtc_read_time(struct device dev, struct rtc_time tm)
d6c7428f	108	{
143d92be	109	struct i2c_client *client = to_i2c_client(dev);
d6c7428f RF	110	uint8_t buf[ISL12022_REG_INT + 1];
	111	int ret;
	112
	113	ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
	114	if (ret)
	115	return ret;
	116
	117	if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 \| ISL12022_SR_LBAT75)) {
	118	dev_warn(&client->dev,
	119	"voltage dropped below %u%%, "
	120	"date and time is not reliable.\n",
	121	buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
	122	}
	123
	124	dev_dbg(&client->dev,
	125	"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
	126	"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
	127	"sr=%02x, int=%02x",
	128	__func__,
	129	buf[ISL12022_REG_SC],
	130	buf[ISL12022_REG_MN],
	131	buf[ISL12022_REG_HR],
	132	buf[ISL12022_REG_DT],
	133	buf[ISL12022_REG_MO],
	134	buf[ISL12022_REG_YR],
	135	buf[ISL12022_REG_DW],
	136	buf[ISL12022_REG_SR],
	137	buf[ISL12022_REG_INT]);
	138
	139	tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
	140	tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
	141	tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
	142	tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
	143	tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
	144	tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
	145	tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
	146
	147	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	148	"mday=%d, mon=%d, year=%d, wday=%d\n",
	149	__func__,
	150	tm->tm_sec, tm->tm_min, tm->tm_hour,
	151	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	152
22652ba7	153	return 0;
d6c7428f RF	154	}
d6c7428f RF	155
143d92be	156	static int isl12022_rtc_set_time(struct device dev, struct rtc_time tm)
d6c7428f	157	{
143d92be	158	struct i2c_client *client = to_i2c_client(dev);
d6c7428f RF	159	struct isl12022 *isl12022 = i2c_get_clientdata(client);
	160	size_t i;
	161	int ret;
	162	uint8_t buf[ISL12022_REG_DW + 1];
	163
	164	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	165	"mday=%d, mon=%d, year=%d, wday=%d\n",
	166	__func__,
	167	tm->tm_sec, tm->tm_min, tm->tm_hour,
	168	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	169
	170	if (!isl12022->write_enabled) {
	171
	172	ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
	173	if (ret)
	174	return ret;
	175
	176	/* Check if WRTC (write rtc enable) is set factory default is
	177	* 0 (not set) */
	178	if (!(buf[0] & ISL12022_INT_WRTC)) {
	179	dev_info(&client->dev,
	180	"init write enable and 24 hour format\n");
	181
	182	/* Set the write enable bit. */
	183	ret = isl12022_write_reg(client,
	184	ISL12022_REG_INT,
	185	buf[0] \| ISL12022_INT_WRTC);
	186	if (ret)
	187	return ret;
	188
	189	/* Write to any RTC register to start RTC, we use the
	190	* HR register, setting the MIL bit to use the 24 hour
	191	* format. */
	192	ret = isl12022_read_regs(client, ISL12022_REG_HR,
	193	buf, 1);
	194	if (ret)
	195	return ret;
	196
	197	ret = isl12022_write_reg(client,
	198	ISL12022_REG_HR,
	199	buf[0] \| ISL12022_HR_MIL);
	200	if (ret)
	201	return ret;
	202	}
	203
c1f5f054	204	isl12022->write_enabled = true;
d6c7428f RF	205	}
	206
	207	/* hours, minutes and seconds */
	208	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
	209	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
6d23b258	210	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) \| ISL12022_HR_MIL;
d6c7428f RF	211
	212	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
	213
	214	/* month, 1 - 12 */
	215	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
	216
	217	/* year and century */
	218	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
	219
	220	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
	221
	222	/* write register's data */
	223	for (i = 0; i < ARRAY_SIZE(buf); i++) {
	224	ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
	225	buf[ISL12022_REG_SC + i]);
	226	if (ret)
	227	return -EIO;
0b7e0392	228	}
d6c7428f RF	229
	230	return 0;
	231	}
	232
d6c7428f RF	233	static const struct rtc_class_ops isl12022_rtc_ops = {
	234	.read_time = isl12022_rtc_read_time,
	235	.set_time = isl12022_rtc_set_time,
	236	};
	237
	238	static int isl12022_probe(struct i2c_client *client,
	239	const struct i2c_device_id *id)
	240	{
	241	struct isl12022 *isl12022;
	242
d6c7428f RF	243	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	244	return -ENODEV;
	245
dc831f97 JH	246	isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
dc831f97 JH	247	GFP_KERNEL);
d6c7428f RF	248	if (!isl12022)
	249	return -ENOMEM;
	250
d6c7428f RF	251	i2c_set_clientdata(client, isl12022);
d6c7428f RF	252
dc831f97 JH	253	isl12022->rtc = devm_rtc_device_register(&client->dev,
	254	isl12022_driver.driver.name,
	255	&isl12022_rtc_ops, THIS_MODULE);
dac30a98	256	return PTR_ERR_OR_ZERO(isl12022->rtc);
d6c7428f RF	257	}
d6c7428f RF	258
db04d628	259	#ifdef CONFIG_OF
a28885bc	260	static const struct of_device_id isl12022_dt_match[] = {
c5cd8273 AE	261	{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
c5cd8273 AE	262	{ .compatible = "isil,isl12022" },
db04d628 SL	263	{ },
db04d628 SL	264	};
1c4fc295	265	MODULE_DEVICE_TABLE(of, isl12022_dt_match);
db04d628 SL	266	#endif
db04d628 SL	267
d6c7428f RF	268	static const struct i2c_device_id isl12022_id[] = {
d6c7428f RF	269	{ "isl12022", 0 },
d6c7428f RF	270	{ }
	271	};
	272	MODULE_DEVICE_TABLE(i2c, isl12022_id);
	273
	274	static struct i2c_driver isl12022_driver = {
	275	.driver = {
	276	.name = "rtc-isl12022",
db04d628 SL	277	#ifdef CONFIG_OF
	278	.of_match_table = of_match_ptr(isl12022_dt_match),
	279	#endif
d6c7428f RF	280	},
d6c7428f RF	281	.probe = isl12022_probe,
d6c7428f RF	282	.id_table = isl12022_id,
	283	};
	284
0abc9201	285	module_i2c_driver(isl12022_driver);
d6c7428f RF	286
	287	MODULE_AUTHOR("[email protected]");
	288	MODULE_DESCRIPTION("ISL 12022 RTC driver");
	289	MODULE_LICENSE("GPL");