[linux-2.6-block.git] / drivers / rtc / rtc-isl12022.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * An I2C driver for the Intersil ISL 12022
 *
 * Author: Roman Fietze <roman.fietze@telemotive.de>
 *
 * Based on the Philips PCF8563 RTC
 * by Alessandro Zummo <a.zummo@towertech.it>.
 */

#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("roman.fietze@telemotive.de");
MODULE_DESCRIPTION("ISL 12022 RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
d6c7428f RF	2	/*
	3	* An I2C driver for the Intersil ISL 12022
	4	*
	5	* Author: Roman Fietze <roman.fietze@telemotive.de>
	6	*
	7	* Based on the Philips PCF8563 RTC
	8	* by Alessandro Zummo <a.zummo@towertech.it>.
d6c7428f RF	9	*/
	10
	11	#include <linux/i2c.h>
	12	#include <linux/bcd.h>
	13	#include <linux/rtc.h>
	14	#include <linux/slab.h>
2113852b	15	#include <linux/module.h>
17cc54b2	16	#include <linux/err.h>
db04d628 SL	17	#include <linux/of.h>
db04d628 SL	18	#include <linux/of_device.h>
d6c7428f	19
d6c7428f RF	20	/* ISL register offsets */
	21	#define ISL12022_REG_SC 0x00
	22	#define ISL12022_REG_MN 0x01
	23	#define ISL12022_REG_HR 0x02
	24	#define ISL12022_REG_DT 0x03
	25	#define ISL12022_REG_MO 0x04
	26	#define ISL12022_REG_YR 0x05
	27	#define ISL12022_REG_DW 0x06
	28
	29	#define ISL12022_REG_SR 0x07
	30	#define ISL12022_REG_INT 0x08
	31
	32	/* ISL register bits */
	33	#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
	34
	35	#define ISL12022_SR_LBAT85 (1 << 2)
	36	#define ISL12022_SR_LBAT75 (1 << 1)
	37
	38	#define ISL12022_INT_WRTC (1 << 6)
	39
	40
	41	static struct i2c_driver isl12022_driver;
	42
	43	struct isl12022 {
	44	struct rtc_device *rtc;
	45
	46	bool write_enabled; /* true if write enable is set */
	47	};
	48
	49
	50	static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
	51	uint8_t *data, size_t n)
	52	{
	53	struct i2c_msg msgs[] = {
	54	{
	55	.addr = client->addr,
	56	.flags = 0,
	57	.len = 1,
	58	.buf = data
	59	}, /* setup read ptr */
	60	{
	61	.addr = client->addr,
	62	.flags = I2C_M_RD,
	63	.len = n,
	64	.buf = data
	65	}
	66	};
	67
	68	int ret;
	69
	70	data[0] = reg;
	71	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	72	if (ret != ARRAY_SIZE(msgs)) {
	73	dev_err(&client->dev, "%s: read error, ret=%d\n",
	74	__func__, ret);
	75	return -EIO;
	76	}
	77
	78	return 0;
	79	}
	80
	81
	82	static int isl12022_write_reg(struct i2c_client *client,
	83	uint8_t reg, uint8_t val)
84	{
85	uint8_t data[2] = { reg, val };
86	int err;
87
88	err = i2c_master_send(client, data, sizeof(data));
89	if (err != sizeof(data)) {
90	dev_err(&client->dev,
91	"%s: err=%d addr=%02x, data=%02x\n",
92	__func__, err, data[0], data[1]);
93	return -EIO;
94	}
95
96	return 0;
97	}
98
99
100	/*
101	* In the routines that deal directly with the isl12022 hardware, we use
102	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
103	*/
143d92be	104	static int isl12022_rtc_read_time(struct device dev, struct rtc_time tm)
d6c7428f	105	{
143d92be	106	struct i2c_client *client = to_i2c_client(dev);
d6c7428f RF	107	uint8_t buf[ISL12022_REG_INT + 1];
	108	int ret;
	109
	110	ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
	111	if (ret)
	112	return ret;
	113
	114	if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 \| ISL12022_SR_LBAT75)) {
	115	dev_warn(&client->dev,
	116	"voltage dropped below %u%%, "
	117	"date and time is not reliable.\n",
	118	buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
	119	}
	120
	121	dev_dbg(&client->dev,
	122	"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
	123	"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
	124	"sr=%02x, int=%02x",
	125	__func__,
	126	buf[ISL12022_REG_SC],
	127	buf[ISL12022_REG_MN],
	128	buf[ISL12022_REG_HR],
	129	buf[ISL12022_REG_DT],
	130	buf[ISL12022_REG_MO],
	131	buf[ISL12022_REG_YR],
	132	buf[ISL12022_REG_DW],
	133	buf[ISL12022_REG_SR],
	134	buf[ISL12022_REG_INT]);
	135
	136	tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
	137	tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
	138	tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
	139	tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
	140	tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
	141	tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
	142	tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
	143
	144	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	145	"mday=%d, mon=%d, year=%d, wday=%d\n",
	146	__func__,
	147	tm->tm_sec, tm->tm_min, tm->tm_hour,
	148	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	149
22652ba7	150	return 0;
d6c7428f RF	151	}
d6c7428f RF	152
143d92be	153	static int isl12022_rtc_set_time(struct device dev, struct rtc_time tm)
d6c7428f	154	{
143d92be	155	struct i2c_client *client = to_i2c_client(dev);
d6c7428f RF	156	struct isl12022 *isl12022 = i2c_get_clientdata(client);
	157	size_t i;
	158	int ret;
	159	uint8_t buf[ISL12022_REG_DW + 1];
	160
	161	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	162	"mday=%d, mon=%d, year=%d, wday=%d\n",
	163	__func__,
	164	tm->tm_sec, tm->tm_min, tm->tm_hour,
	165	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	166
	167	if (!isl12022->write_enabled) {
	168
	169	ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
	170	if (ret)
	171	return ret;
	172
	173	/* Check if WRTC (write rtc enable) is set factory default is
	174	* 0 (not set) */
	175	if (!(buf[0] & ISL12022_INT_WRTC)) {
	176	dev_info(&client->dev,
	177	"init write enable and 24 hour format\n");
	178
	179	/* Set the write enable bit. */
	180	ret = isl12022_write_reg(client,
	181	ISL12022_REG_INT,
	182	buf[0] \| ISL12022_INT_WRTC);
	183	if (ret)
	184	return ret;
	185
	186	/* Write to any RTC register to start RTC, we use the
	187	* HR register, setting the MIL bit to use the 24 hour
	188	* format. */
	189	ret = isl12022_read_regs(client, ISL12022_REG_HR,
	190	buf, 1);
	191	if (ret)
	192	return ret;
	193
	194	ret = isl12022_write_reg(client,
	195	ISL12022_REG_HR,
	196	buf[0] \| ISL12022_HR_MIL);
	197	if (ret)
	198	return ret;
	199	}
	200
c1f5f054	201	isl12022->write_enabled = true;
d6c7428f RF	202	}
	203
	204	/* hours, minutes and seconds */
	205	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
	206	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
6d23b258	207	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) \| ISL12022_HR_MIL;
d6c7428f RF	208
	209	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
	210
	211	/* month, 1 - 12 */
	212	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
	213
	214	/* year and century */
	215	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
	216
	217	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
	218
	219	/* write register's data */
	220	for (i = 0; i < ARRAY_SIZE(buf); i++) {
	221	ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
	222	buf[ISL12022_REG_SC + i]);
	223	if (ret)
	224	return -EIO;
0b7e0392	225	}
d6c7428f RF	226
	227	return 0;
	228	}
	229
d6c7428f RF	230	static const struct rtc_class_ops isl12022_rtc_ops = {
	231	.read_time = isl12022_rtc_read_time,
	232	.set_time = isl12022_rtc_set_time,
	233	};
	234
	235	static int isl12022_probe(struct i2c_client *client,
	236	const struct i2c_device_id *id)
	237	{
	238	struct isl12022 *isl12022;
	239
d6c7428f RF	240	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	241	return -ENODEV;
	242
dc831f97 JH	243	isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
dc831f97 JH	244	GFP_KERNEL);
d6c7428f RF	245	if (!isl12022)
	246	return -ENOMEM;
	247
d6c7428f RF	248	i2c_set_clientdata(client, isl12022);
d6c7428f RF	249
dc831f97 JH	250	isl12022->rtc = devm_rtc_device_register(&client->dev,
	251	isl12022_driver.driver.name,
	252	&isl12022_rtc_ops, THIS_MODULE);
dac30a98	253	return PTR_ERR_OR_ZERO(isl12022->rtc);
d6c7428f RF	254	}
d6c7428f RF	255
db04d628	256	#ifdef CONFIG_OF
a28885bc	257	static const struct of_device_id isl12022_dt_match[] = {
c5cd8273 AE	258	{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
c5cd8273 AE	259	{ .compatible = "isil,isl12022" },
db04d628 SL	260	{ },
db04d628 SL	261	};
1c4fc295	262	MODULE_DEVICE_TABLE(of, isl12022_dt_match);
db04d628 SL	263	#endif
db04d628 SL	264
d6c7428f RF	265	static const struct i2c_device_id isl12022_id[] = {
d6c7428f RF	266	{ "isl12022", 0 },
d6c7428f RF	267	{ }
	268	};
	269	MODULE_DEVICE_TABLE(i2c, isl12022_id);
	270
	271	static struct i2c_driver isl12022_driver = {
	272	.driver = {
	273	.name = "rtc-isl12022",
db04d628 SL	274	#ifdef CONFIG_OF
	275	.of_match_table = of_match_ptr(isl12022_dt_match),
	276	#endif
d6c7428f RF	277	},
d6c7428f RF	278	.probe = isl12022_probe,
d6c7428f RF	279	.id_table = isl12022_id,
	280	};
	281
0abc9201	282	module_i2c_driver(isl12022_driver);
d6c7428f RF	283
	284	MODULE_AUTHOR("roman.fietze@telemotive.de");
	285	MODULE_DESCRIPTION("ISL 12022 RTC driver");
	286	MODULE_LICENSE("GPL");