[linux-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>
#include <linux/regmap.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;
	struct regmap *regmap;
};

/*
 * 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 isl12022 *isl12022 = dev_get_drvdata(dev);
	struct regmap *regmap = isl12022->regmap;
	uint8_t buf[ISL12022_REG_INT + 1];
	int ret;

	ret = regmap_bulk_read(regmap, ISL12022_REG_SC, buf, sizeof(buf));
	if (ret)
		return ret;

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

	dev_dbg(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(dev, "%s: %ptR\n", __func__, tm);

	return 0;
}

static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct isl12022 *isl12022 = dev_get_drvdata(dev);
	struct regmap *regmap = isl12022->regmap;
	int ret;
	uint8_t buf[ISL12022_REG_DW + 1];

	dev_dbg(dev, "%s: %ptR\n", __func__, tm);

	/* Ensure the write enable bit is set. */
	ret = regmap_update_bits(regmap, ISL12022_REG_INT,
				 ISL12022_INT_WRTC, ISL12022_INT_WRTC);
	if (ret)
		return ret;

	/* 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;

	return regmap_bulk_write(isl12022->regmap, ISL12022_REG_SC,
				 buf, sizeof(buf));
}

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

static const struct regmap_config regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.use_single_write = true,
};

static int isl12022_probe(struct i2c_client *client)
{
	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;
	dev_set_drvdata(&client->dev, isl12022);

	isl12022->regmap = devm_regmap_init_i2c(client, &regmap_config);
	if (IS_ERR(isl12022->regmap)) {
		dev_err(&client->dev, "regmap allocation failed\n");
		return PTR_ERR(isl12022->regmap);
	}

	isl12022->rtc = devm_rtc_allocate_device(&client->dev);
	if (IS_ERR(isl12022->rtc))
		return PTR_ERR(isl12022->rtc);

	isl12022->rtc->ops = &isl12022_rtc_ops;
	isl12022->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	isl12022->rtc->range_max = RTC_TIMESTAMP_END_2099;

	return devm_rtc_register_device(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_new	= 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>
b1a1baa6	19	#include <linux/regmap.h>
d6c7428f	20
d6c7428f RF	21	/* ISL register offsets */
	22	#define ISL12022_REG_SC 0x00
	23	#define ISL12022_REG_MN 0x01
	24	#define ISL12022_REG_HR 0x02
	25	#define ISL12022_REG_DT 0x03
	26	#define ISL12022_REG_MO 0x04
	27	#define ISL12022_REG_YR 0x05
	28	#define ISL12022_REG_DW 0x06
	29
	30	#define ISL12022_REG_SR 0x07
	31	#define ISL12022_REG_INT 0x08
	32
	33	/* ISL register bits */
	34	#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
	35
	36	#define ISL12022_SR_LBAT85 (1 << 2)
	37	#define ISL12022_SR_LBAT75 (1 << 1)
	38
	39	#define ISL12022_INT_WRTC (1 << 6)
	40
	41
	42	static struct i2c_driver isl12022_driver;
	43
	44	struct isl12022 {
	45	struct rtc_device *rtc;
b1a1baa6	46	struct regmap *regmap;
d6c7428f RF	47	};
d6c7428f RF	48
d6c7428f RF	49	/*
	50	* In the routines that deal directly with the isl12022 hardware, we use
	51	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	52	*/
143d92be	53	static int isl12022_rtc_read_time(struct device dev, struct rtc_time tm)
d6c7428f	54	{
b1a1baa6 RV	55	struct isl12022 *isl12022 = dev_get_drvdata(dev);
b1a1baa6 RV	56	struct regmap *regmap = isl12022->regmap;
d6c7428f RF	57	uint8_t buf[ISL12022_REG_INT + 1];
	58	int ret;
	59
b1a1baa6	60	ret = regmap_bulk_read(regmap, ISL12022_REG_SC, buf, sizeof(buf));
d6c7428f RF	61	if (ret)
	62	return ret;
	63
	64	if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 \| ISL12022_SR_LBAT75)) {
ca358871	65	dev_warn(dev,
d6c7428f RF	66	"voltage dropped below %u%%, "
	67	"date and time is not reliable.\n",
	68	buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
	69	}
	70
ca358871	71	dev_dbg(dev,
d6c7428f RF	72	"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
	73	"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
	74	"sr=%02x, int=%02x",
	75	__func__,
	76	buf[ISL12022_REG_SC],
	77	buf[ISL12022_REG_MN],
	78	buf[ISL12022_REG_HR],
	79	buf[ISL12022_REG_DT],
	80	buf[ISL12022_REG_MO],
	81	buf[ISL12022_REG_YR],
	82	buf[ISL12022_REG_DW],
	83	buf[ISL12022_REG_SR],
	84	buf[ISL12022_REG_INT]);
	85
	86	tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
	87	tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
	88	tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
	89	tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
	90	tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
	91	tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
	92	tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
	93
7093b8a4	94	dev_dbg(dev, "%s: %ptR\n", __func__, tm);
d6c7428f	95
22652ba7	96	return 0;
d6c7428f RF	97	}
d6c7428f RF	98
143d92be	99	static int isl12022_rtc_set_time(struct device dev, struct rtc_time tm)
d6c7428f	100	{
31b108ac	101	struct isl12022 *isl12022 = dev_get_drvdata(dev);
b1a1baa6	102	struct regmap *regmap = isl12022->regmap;
d6c7428f RF	103	int ret;
	104	uint8_t buf[ISL12022_REG_DW + 1];
	105
7093b8a4	106	dev_dbg(dev, "%s: %ptR\n", __func__, tm);
d6c7428f	107
b1a1baa6 RV	108	/* Ensure the write enable bit is set. */
	109	ret = regmap_update_bits(regmap, ISL12022_REG_INT,
	110	ISL12022_INT_WRTC, ISL12022_INT_WRTC);
	111	if (ret)
	112	return ret;
d6c7428f RF	113
	114	/* hours, minutes and seconds */
	115	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
	116	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
6d23b258	117	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) \| ISL12022_HR_MIL;
d6c7428f RF	118
	119	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
	120
	121	/* month, 1 - 12 */
	122	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
	123
	124	/* year and century */
	125	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
	126
	127	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
	128
b1a1baa6 RV	129	return regmap_bulk_write(isl12022->regmap, ISL12022_REG_SC,
b1a1baa6 RV	130	buf, sizeof(buf));
d6c7428f RF	131	}
d6c7428f RF	132
d6c7428f RF	133	static const struct rtc_class_ops isl12022_rtc_ops = {
	134	.read_time = isl12022_rtc_read_time,
	135	.set_time = isl12022_rtc_set_time,
	136	};
	137
b1a1baa6 RV	138	static const struct regmap_config regmap_config = {
	139	.reg_bits = 8,
	140	.val_bits = 8,
	141	.use_single_write = true,
	142	};
	143
3f4a3322	144	static int isl12022_probe(struct i2c_client *client)
d6c7428f RF	145	{
	146	struct isl12022 *isl12022;
	147
d6c7428f RF	148	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	149	return -ENODEV;
	150
dc831f97 JH	151	isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
dc831f97 JH	152	GFP_KERNEL);
d6c7428f RF	153	if (!isl12022)
d6c7428f RF	154	return -ENOMEM;
31b108ac	155	dev_set_drvdata(&client->dev, isl12022);
d6c7428f	156
b1a1baa6 RV	157	isl12022->regmap = devm_regmap_init_i2c(client, &regmap_config);
	158	if (IS_ERR(isl12022->regmap)) {
	159	dev_err(&client->dev, "regmap allocation failed\n");
	160	return PTR_ERR(isl12022->regmap);
	161	}
	162
a35a2ad2 RV	163	isl12022->rtc = devm_rtc_allocate_device(&client->dev);
	164	if (IS_ERR(isl12022->rtc))
	165	return PTR_ERR(isl12022->rtc);
	166
	167	isl12022->rtc->ops = &isl12022_rtc_ops;
ca03b7a2 RV	168	isl12022->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
ca03b7a2 RV	169	isl12022->rtc->range_max = RTC_TIMESTAMP_END_2099;
a35a2ad2 RV	170
a35a2ad2 RV	171	return devm_rtc_register_device(isl12022->rtc);
d6c7428f RF	172	}
d6c7428f RF	173
db04d628	174	#ifdef CONFIG_OF
a28885bc	175	static const struct of_device_id isl12022_dt_match[] = {
c5cd8273 AE	176	{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
c5cd8273 AE	177	{ .compatible = "isil,isl12022" },
db04d628 SL	178	{ },
db04d628 SL	179	};
1c4fc295	180	MODULE_DEVICE_TABLE(of, isl12022_dt_match);
db04d628 SL	181	#endif
db04d628 SL	182
d6c7428f RF	183	static const struct i2c_device_id isl12022_id[] = {
d6c7428f RF	184	{ "isl12022", 0 },
d6c7428f RF	185	{ }
	186	};
	187	MODULE_DEVICE_TABLE(i2c, isl12022_id);
	188
	189	static struct i2c_driver isl12022_driver = {
	190	.driver = {
	191	.name = "rtc-isl12022",
db04d628 SL	192	#ifdef CONFIG_OF
	193	.of_match_table = of_match_ptr(isl12022_dt_match),
	194	#endif
d6c7428f	195	},
3f4a3322	196	.probe_new = isl12022_probe,
d6c7428f RF	197	.id_table = isl12022_id,
	198	};
	199
0abc9201	200	module_i2c_driver(isl12022_driver);
d6c7428f RF	201
	202	MODULE_AUTHOR("roman.fietze@telemotive.de");
	203	MODULE_DESCRIPTION("ISL 12022 RTC driver");
	204	MODULE_LICENSE("GPL");