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

/*
 * 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>.
 *
 * 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>

#define DRV_VERSION "0.1"

/* 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);

	/* The clock can give out invalid datetime, but we cannot return
	 * -EINVAL otherwise hwclock will refuse to set the time on bootup. */
	if (rtc_valid_tm(tm) < 0)
		dev_err(&client->dev, "retrieved date and time is invalid.\n");

	return 0;
}

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;

	dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");

	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" },
	{ },
};
#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");
MODULE_VERSION(DRV_VERSION);
Commit	Line	Data
d6c7428f RF	1	/*
	2	* An I2C driver for the Intersil ISL 12022
	3	*
	4	* Author: Roman Fietze <roman.fietze@telemotive.de>
	5	*
	6	* Based on the Philips PCF8563 RTC
	7	* by Alessandro Zummo <a.zummo@towertech.it>.
	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 RF	22
	23	#define DRV_VERSION "0.1"
	24
	25	/* ISL register offsets */
	26	#define ISL12022_REG_SC 0x00
	27	#define ISL12022_REG_MN 0x01
	28	#define ISL12022_REG_HR 0x02
	29	#define ISL12022_REG_DT 0x03
	30	#define ISL12022_REG_MO 0x04
	31	#define ISL12022_REG_YR 0x05
	32	#define ISL12022_REG_DW 0x06
	33
	34	#define ISL12022_REG_SR 0x07
	35	#define ISL12022_REG_INT 0x08
	36
	37	/* ISL register bits */
	38	#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
	39
	40	#define ISL12022_SR_LBAT85 (1 << 2)
	41	#define ISL12022_SR_LBAT75 (1 << 1)
	42
	43	#define ISL12022_INT_WRTC (1 << 6)
	44
	45
	46	static struct i2c_driver isl12022_driver;
	47
	48	struct isl12022 {
	49	struct rtc_device *rtc;
	50
	51	bool write_enabled; /* true if write enable is set */
	52	};
	53
	54
	55	static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
	56	uint8_t *data, size_t n)
	57	{
	58	struct i2c_msg msgs[] = {
	59	{
	60	.addr = client->addr,
	61	.flags = 0,
	62	.len = 1,
	63	.buf = data
	64	}, /* setup read ptr */
	65	{
	66	.addr = client->addr,
	67	.flags = I2C_M_RD,
	68	.len = n,
	69	.buf = data
	70	}
	71	};
	72
	73	int ret;
	74
	75	data[0] = reg;
	76	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	77	if (ret != ARRAY_SIZE(msgs)) {
	78	dev_err(&client->dev, "%s: read error, ret=%d\n",
	79	__func__, ret);
	80	return -EIO;
	81	}
	82
	83	return 0;
	84	}
	85
86
87	static int isl12022_write_reg(struct i2c_client *client,
88	uint8_t reg, uint8_t val)
89	{
90	uint8_t data[2] = { reg, val };
91	int err;
92
93	err = i2c_master_send(client, data, sizeof(data));
94	if (err != sizeof(data)) {
95	dev_err(&client->dev,
96	"%s: err=%d addr=%02x, data=%02x\n",
97	__func__, err, data[0], data[1]);
98	return -EIO;
99	}
100
101	return 0;
102	}
103
104
105	/*
106	* In the routines that deal directly with the isl12022 hardware, we use
107	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
108	*/
109	static int isl12022_get_datetime(struct i2c_client client, struct rtc_time tm)
110	{
111	uint8_t buf[ISL12022_REG_INT + 1];
112	int ret;
113
114	ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
115	if (ret)
116	return ret;
117
118	if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 \| ISL12022_SR_LBAT75)) {
119	dev_warn(&client->dev,
120	"voltage dropped below %u%%, "
121	"date and time is not reliable.\n",
122	buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
123	}
124
125	dev_dbg(&client->dev,
126	"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
127	"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
128	"sr=%02x, int=%02x",
129	__func__,
130	buf[ISL12022_REG_SC],
131	buf[ISL12022_REG_MN],
132	buf[ISL12022_REG_HR],
133	buf[ISL12022_REG_DT],
134	buf[ISL12022_REG_MO],
135	buf[ISL12022_REG_YR],
136	buf[ISL12022_REG_DW],
137	buf[ISL12022_REG_SR],
138	buf[ISL12022_REG_INT]);
139
140	tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
141	tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
142	tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
143	tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
144	tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
145	tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
146	tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
147
148	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
149	"mday=%d, mon=%d, year=%d, wday=%d\n",
150	__func__,
151	tm->tm_sec, tm->tm_min, tm->tm_hour,
152	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
153
154	/* The clock can give out invalid datetime, but we cannot return
155	* -EINVAL otherwise hwclock will refuse to set the time on bootup. */
156	if (rtc_valid_tm(tm) < 0)
157	dev_err(&client->dev, "retrieved date and time is invalid.\n");
158
159	return 0;
160	}
161
162	static int isl12022_set_datetime(struct i2c_client client, struct rtc_time tm)
163	{
164	struct isl12022 *isl12022 = i2c_get_clientdata(client);
165	size_t i;
166	int ret;
167	uint8_t buf[ISL12022_REG_DW + 1];
168
169	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
170	"mday=%d, mon=%d, year=%d, wday=%d\n",
171	__func__,
172	tm->tm_sec, tm->tm_min, tm->tm_hour,
173	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
174
175	if (!isl12022->write_enabled) {
176
177	ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
178	if (ret)
179	return ret;
180
181	/* Check if WRTC (write rtc enable) is set factory default is
182	* 0 (not set) */
183	if (!(buf[0] & ISL12022_INT_WRTC)) {
184	dev_info(&client->dev,
185	"init write enable and 24 hour format\n");
186
187	/* Set the write enable bit. */
188	ret = isl12022_write_reg(client,
189	ISL12022_REG_INT,
190	buf[0] \| ISL12022_INT_WRTC);
191	if (ret)
192	return ret;
193
194	/* Write to any RTC register to start RTC, we use the
195	* HR register, setting the MIL bit to use the 24 hour
196	* format. */
197	ret = isl12022_read_regs(client, ISL12022_REG_HR,
198	buf, 1);
199	if (ret)
200	return ret;
201
202	ret = isl12022_write_reg(client,
203	ISL12022_REG_HR,
204	buf[0] \| ISL12022_HR_MIL);
205	if (ret)
206	return ret;
207	}
208
209	isl12022->write_enabled = 1;
210	}
211
212	/* hours, minutes and seconds */
213	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
214	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
6d23b258	215	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) \| ISL12022_HR_MIL;
d6c7428f RF	216
	217	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
	218
	219	/* month, 1 - 12 */
	220	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
	221
	222	/* year and century */
	223	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
	224
	225	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
	226
	227	/* write register's data */
	228	for (i = 0; i < ARRAY_SIZE(buf); i++) {
	229	ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
	230	buf[ISL12022_REG_SC + i]);
	231	if (ret)
	232	return -EIO;
0b7e0392	233	}
d6c7428f RF	234
	235	return 0;
	236	}
	237
	238	static int isl12022_rtc_read_time(struct device dev, struct rtc_time tm)
	239	{
	240	return isl12022_get_datetime(to_i2c_client(dev), tm);
	241	}
	242
	243	static int isl12022_rtc_set_time(struct device dev, struct rtc_time tm)
	244	{
	245	return isl12022_set_datetime(to_i2c_client(dev), tm);
	246	}
	247
	248	static const struct rtc_class_ops isl12022_rtc_ops = {
	249	.read_time = isl12022_rtc_read_time,
	250	.set_time = isl12022_rtc_set_time,
	251	};
	252
	253	static int isl12022_probe(struct i2c_client *client,
	254	const struct i2c_device_id *id)
	255	{
	256	struct isl12022 *isl12022;
	257
d6c7428f RF	258	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	259	return -ENODEV;
	260
dc831f97 JH	261	isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
dc831f97 JH	262	GFP_KERNEL);
d6c7428f RF	263	if (!isl12022)
	264	return -ENOMEM;
	265
	266	dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");
	267
	268	i2c_set_clientdata(client, isl12022);
	269
dc831f97 JH	270	isl12022->rtc = devm_rtc_device_register(&client->dev,
	271	isl12022_driver.driver.name,
	272	&isl12022_rtc_ops, THIS_MODULE);
dac30a98	273	return PTR_ERR_OR_ZERO(isl12022->rtc);
d6c7428f RF	274	}
d6c7428f RF	275
db04d628	276	#ifdef CONFIG_OF
a28885bc	277	static const struct of_device_id isl12022_dt_match[] = {
c5cd8273 AE	278	{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
c5cd8273 AE	279	{ .compatible = "isil,isl12022" },
db04d628 SL	280	{ },
	281	};
	282	#endif
	283
d6c7428f RF	284	static const struct i2c_device_id isl12022_id[] = {
d6c7428f RF	285	{ "isl12022", 0 },
d6c7428f RF	286	{ }
	287	};
	288	MODULE_DEVICE_TABLE(i2c, isl12022_id);
	289
	290	static struct i2c_driver isl12022_driver = {
	291	.driver = {
	292	.name = "rtc-isl12022",
db04d628 SL	293	#ifdef CONFIG_OF
	294	.of_match_table = of_match_ptr(isl12022_dt_match),
	295	#endif
d6c7428f RF	296	},
d6c7428f RF	297	.probe = isl12022_probe,
d6c7428f RF	298	.id_table = isl12022_id,
	299	};
	300
0abc9201	301	module_i2c_driver(isl12022_driver);
d6c7428f RF	302
	303	MODULE_AUTHOR("roman.fietze@telemotive.de");
	304	MODULE_DESCRIPTION("ISL 12022 RTC driver");
	305	MODULE_LICENSE("GPL");
	306	MODULE_VERSION(DRV_VERSION);