[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_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	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 rtc_valid_tm(tm);
}

static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	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 = 1;
	}

	/* 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 int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return isl12022_get_datetime(to_i2c_client(dev), tm);
}

static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return isl12022_set_datetime(to_i2c_client(dev), tm);
}

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	*/
107	static int isl12022_get_datetime(struct i2c_client client, struct rtc_time tm)
108	{
109	uint8_t buf[ISL12022_REG_INT + 1];
110	int ret;
111
112	ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
113	if (ret)
114	return ret;
115
116	if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 \| ISL12022_SR_LBAT75)) {
117	dev_warn(&client->dev,
118	"voltage dropped below %u%%, "
119	"date and time is not reliable.\n",
120	buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
121	}
122
123	dev_dbg(&client->dev,
124	"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
125	"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
126	"sr=%02x, int=%02x",
127	__func__,
128	buf[ISL12022_REG_SC],
129	buf[ISL12022_REG_MN],
130	buf[ISL12022_REG_HR],
131	buf[ISL12022_REG_DT],
132	buf[ISL12022_REG_MO],
133	buf[ISL12022_REG_YR],
134	buf[ISL12022_REG_DW],
135	buf[ISL12022_REG_SR],
136	buf[ISL12022_REG_INT]);
137
138	tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
139	tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
140	tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
141	tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
142	tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
143	tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
144	tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
145
146	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
147	"mday=%d, mon=%d, year=%d, wday=%d\n",
148	__func__,
149	tm->tm_sec, tm->tm_min, tm->tm_hour,
150	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
151
821f51c4	152	return rtc_valid_tm(tm);
d6c7428f RF	153	}
	154
	155	static int isl12022_set_datetime(struct i2c_client client, struct rtc_time tm)
	156	{
	157	struct isl12022 *isl12022 = i2c_get_clientdata(client);
	158	size_t i;
	159	int ret;
	160	uint8_t buf[ISL12022_REG_DW + 1];
	161
	162	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	163	"mday=%d, mon=%d, year=%d, wday=%d\n",
	164	__func__,
	165	tm->tm_sec, tm->tm_min, tm->tm_hour,
	166	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	167
	168	if (!isl12022->write_enabled) {
	169
	170	ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
	171	if (ret)
	172	return ret;
	173
	174	/* Check if WRTC (write rtc enable) is set factory default is
	175	* 0 (not set) */
	176	if (!(buf[0] & ISL12022_INT_WRTC)) {
	177	dev_info(&client->dev,
	178	"init write enable and 24 hour format\n");
	179
	180	/* Set the write enable bit. */
	181	ret = isl12022_write_reg(client,
	182	ISL12022_REG_INT,
	183	buf[0] \| ISL12022_INT_WRTC);
	184	if (ret)
	185	return ret;
	186
	187	/* Write to any RTC register to start RTC, we use the
	188	* HR register, setting the MIL bit to use the 24 hour
	189	* format. */
	190	ret = isl12022_read_regs(client, ISL12022_REG_HR,
	191	buf, 1);
	192	if (ret)
	193	return ret;
	194
	195	ret = isl12022_write_reg(client,
	196	ISL12022_REG_HR,
	197	buf[0] \| ISL12022_HR_MIL);
	198	if (ret)
	199	return ret;
	200	}
	201
	202	isl12022->write_enabled = 1;
	203	}
	204
	205	/* hours, minutes and seconds */
	206	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
	207	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
6d23b258	208	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) \| ISL12022_HR_MIL;
d6c7428f RF	209
	210	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
	211
	212	/* month, 1 - 12 */
	213	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
	214
	215	/* year and century */
	216	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
	217
	218	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
	219
	220	/* write register's data */
	221	for (i = 0; i < ARRAY_SIZE(buf); i++) {
	222	ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
	223	buf[ISL12022_REG_SC + i]);
	224	if (ret)
	225	return -EIO;
0b7e0392	226	}
d6c7428f RF	227
	228	return 0;
	229	}
	230
	231	static int isl12022_rtc_read_time(struct device dev, struct rtc_time tm)
	232	{
	233	return isl12022_get_datetime(to_i2c_client(dev), tm);
	234	}
	235
	236	static int isl12022_rtc_set_time(struct device dev, struct rtc_time tm)
	237	{
	238	return isl12022_set_datetime(to_i2c_client(dev), tm);
	239	}
	240
	241	static const struct rtc_class_ops isl12022_rtc_ops = {
	242	.read_time = isl12022_rtc_read_time,
	243	.set_time = isl12022_rtc_set_time,
	244	};
	245
	246	static int isl12022_probe(struct i2c_client *client,
	247	const struct i2c_device_id *id)
	248	{
	249	struct isl12022 *isl12022;
	250
d6c7428f RF	251	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	252	return -ENODEV;
	253
dc831f97 JH	254	isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
dc831f97 JH	255	GFP_KERNEL);
d6c7428f RF	256	if (!isl12022)
	257	return -ENOMEM;
	258
d6c7428f RF	259	i2c_set_clientdata(client, isl12022);
d6c7428f RF	260
dc831f97 JH	261	isl12022->rtc = devm_rtc_device_register(&client->dev,
	262	isl12022_driver.driver.name,
	263	&isl12022_rtc_ops, THIS_MODULE);
dac30a98	264	return PTR_ERR_OR_ZERO(isl12022->rtc);
d6c7428f RF	265	}
d6c7428f RF	266
db04d628	267	#ifdef CONFIG_OF
a28885bc	268	static const struct of_device_id isl12022_dt_match[] = {
c5cd8273 AE	269	{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
c5cd8273 AE	270	{ .compatible = "isil,isl12022" },
db04d628 SL	271	{ },
db04d628 SL	272	};
1c4fc295	273	MODULE_DEVICE_TABLE(of, isl12022_dt_match);
db04d628 SL	274	#endif
db04d628 SL	275
d6c7428f RF	276	static const struct i2c_device_id isl12022_id[] = {
d6c7428f RF	277	{ "isl12022", 0 },
d6c7428f RF	278	{ }
	279	};
	280	MODULE_DEVICE_TABLE(i2c, isl12022_id);
	281
	282	static struct i2c_driver isl12022_driver = {
	283	.driver = {
	284	.name = "rtc-isl12022",
db04d628 SL	285	#ifdef CONFIG_OF
	286	.of_match_table = of_match_ptr(isl12022_dt_match),
	287	#endif
d6c7428f RF	288	},
d6c7428f RF	289	.probe = isl12022_probe,
d6c7428f RF	290	.id_table = isl12022_id,
	291	};
	292
0abc9201	293	module_i2c_driver(isl12022_driver);
d6c7428f RF	294
	295	MODULE_AUTHOR("[email protected]");
	296	MODULE_DESCRIPTION("ISL 12022 RTC driver");
	297	MODULE_LICENSE("GPL");