[net-next-2.6.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>

#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;

	int ret = 0;

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

	isl12022 = kzalloc(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 = rtc_device_register(isl12022_driver.driver.name,
					    &client->dev,
					    &isl12022_rtc_ops,
					    THIS_MODULE);

	if (IS_ERR(isl12022->rtc)) {
		ret = PTR_ERR(isl12022->rtc);
		goto exit_kfree;
	}

	return 0;

exit_kfree:
	kfree(isl12022);

	return ret;
}

static int isl12022_remove(struct i2c_client *client)
{
	struct isl12022 *isl12022 = i2c_get_clientdata(client);

	rtc_device_unregister(isl12022->rtc);
	kfree(isl12022);

	return 0;
}

static const struct i2c_device_id isl12022_id[] = {
	{ "isl12022", 0 },
	{ "rtc8564", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, isl12022_id);

static struct i2c_driver isl12022_driver = {
	.driver		= {
		.name	= "rtc-isl12022",
	},
	.probe		= isl12022_probe,
	.remove		= isl12022_remove,
	.id_table	= isl12022_id,
};

static int __init isl12022_init(void)
{
	return i2c_add_driver(&isl12022_driver);
}

static void __exit isl12022_exit(void)
{
	i2c_del_driver(&isl12022_driver);
}

module_init(isl12022_init);
module_exit(isl12022_exit);

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>
	18
	19	#define DRV_VERSION "0.1"
	20
	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;
	46
	47	bool write_enabled; /* true if write enable is set */
	48	};
	49
	50
	51	static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
	52	uint8_t *data, size_t n)
	53	{
	54	struct i2c_msg msgs[] = {
	55	{
	56	.addr = client->addr,
	57	.flags = 0,
	58	.len = 1,
	59	.buf = data
	60	}, /* setup read ptr */
	61	{
	62	.addr = client->addr,
	63	.flags = I2C_M_RD,
	64	.len = n,
65	.buf = data
66	}
67	};
68
69	int ret;
70
71	data[0] = reg;
72	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
73	if (ret != ARRAY_SIZE(msgs)) {
74	dev_err(&client->dev, "%s: read error, ret=%d\n",
75	__func__, ret);
76	return -EIO;
77	}
78
79	return 0;
80	}
81
82
83	static int isl12022_write_reg(struct i2c_client *client,
84	uint8_t reg, uint8_t val)
85	{
86	uint8_t data[2] = { reg, val };
87	int err;
88
89	err = i2c_master_send(client, data, sizeof(data));
90	if (err != sizeof(data)) {
91	dev_err(&client->dev,
92	"%s: err=%d addr=%02x, data=%02x\n",
93	__func__, err, data[0], data[1]);
94	return -EIO;
95	}
96
97	return 0;
98	}
99
100
101	/*
102	* In the routines that deal directly with the isl12022 hardware, we use
103	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
104	*/
105	static int isl12022_get_datetime(struct i2c_client client, struct rtc_time tm)
106	{
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
150	/* The clock can give out invalid datetime, but we cannot return
151	* -EINVAL otherwise hwclock will refuse to set the time on bootup. */
152	if (rtc_valid_tm(tm) < 0)
153	dev_err(&client->dev, "retrieved date and time is invalid.\n");
154
155	return 0;
156	}
157
158	static int isl12022_set_datetime(struct i2c_client client, struct rtc_time tm)
159	{
160	struct isl12022 *isl12022 = i2c_get_clientdata(client);
161	size_t i;
162	int ret;
163	uint8_t buf[ISL12022_REG_DW + 1];
164
165	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
166	"mday=%d, mon=%d, year=%d, wday=%d\n",
167	__func__,
168	tm->tm_sec, tm->tm_min, tm->tm_hour,
169	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
170
171	if (!isl12022->write_enabled) {
172
173	ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
174	if (ret)
175	return ret;
176
177	/* Check if WRTC (write rtc enable) is set factory default is
178	* 0 (not set) */
179	if (!(buf[0] & ISL12022_INT_WRTC)) {
180	dev_info(&client->dev,
181	"init write enable and 24 hour format\n");
182
183	/* Set the write enable bit. */
184	ret = isl12022_write_reg(client,
185	ISL12022_REG_INT,
186	buf[0] \| ISL12022_INT_WRTC);
187	if (ret)
188	return ret;
189
190	/* Write to any RTC register to start RTC, we use the
191	* HR register, setting the MIL bit to use the 24 hour
192	* format. */
193	ret = isl12022_read_regs(client, ISL12022_REG_HR,
194	buf, 1);
195	if (ret)
196	return ret;
197
198	ret = isl12022_write_reg(client,
199	ISL12022_REG_HR,
200	buf[0] \| ISL12022_HR_MIL);
201	if (ret)
202	return ret;
203	}
204
205	isl12022->write_enabled = 1;
206	}
207
208	/* hours, minutes and seconds */
209	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
210	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
6d23b258	211	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) \| ISL12022_HR_MIL;
d6c7428f RF	212
	213	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
	214
	215	/* month, 1 - 12 */
	216	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
	217
	218	/* year and century */
	219	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
	220
	221	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
	222
	223	/* write register's data */
	224	for (i = 0; i < ARRAY_SIZE(buf); i++) {
	225	ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
	226	buf[ISL12022_REG_SC + i]);
	227	if (ret)
	228	return -EIO;
	229	};
	230
	231	return 0;
	232	}
	233
	234	static int isl12022_rtc_read_time(struct device dev, struct rtc_time tm)
	235	{
	236	return isl12022_get_datetime(to_i2c_client(dev), tm);
	237	}
	238
	239	static int isl12022_rtc_set_time(struct device dev, struct rtc_time tm)
	240	{
	241	return isl12022_set_datetime(to_i2c_client(dev), tm);
	242	}
	243
	244	static const struct rtc_class_ops isl12022_rtc_ops = {
	245	.read_time = isl12022_rtc_read_time,
	246	.set_time = isl12022_rtc_set_time,
	247	};
	248
	249	static int isl12022_probe(struct i2c_client *client,
	250	const struct i2c_device_id *id)
	251	{
	252	struct isl12022 *isl12022;
	253
	254	int ret = 0;
	255
	256	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	257	return -ENODEV;
	258
	259	isl12022 = kzalloc(sizeof(struct isl12022), GFP_KERNEL);
	260	if (!isl12022)
	261	return -ENOMEM;
	262
	263	dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");
	264
	265	i2c_set_clientdata(client, isl12022);
	266
	267	isl12022->rtc = rtc_device_register(isl12022_driver.driver.name,
	268	&client->dev,
	269	&isl12022_rtc_ops,
	270	THIS_MODULE);
	271
	272	if (IS_ERR(isl12022->rtc)) {
	273	ret = PTR_ERR(isl12022->rtc);
	274	goto exit_kfree;
	275	}
276
277	return 0;
278
279	exit_kfree:
280	kfree(isl12022);
281
282	return ret;
283	}
284
285	static int isl12022_remove(struct i2c_client *client)
286	{
287	struct isl12022 *isl12022 = i2c_get_clientdata(client);
288
289	rtc_device_unregister(isl12022->rtc);
290	kfree(isl12022);
291
292	return 0;
293	}
294
295	static const struct i2c_device_id isl12022_id[] = {
296	{ "isl12022", 0 },
297	{ "rtc8564", 0 },
298	{ }
299	};
300	MODULE_DEVICE_TABLE(i2c, isl12022_id);
301
302	static struct i2c_driver isl12022_driver = {
303	.driver = {
304	.name = "rtc-isl12022",
305	},
306	.probe = isl12022_probe,
307	.remove = isl12022_remove,
308	.id_table = isl12022_id,
309	};
310
311	static int __init isl12022_init(void)
312	{
313	return i2c_add_driver(&isl12022_driver);
314	}
315
316	static void __exit isl12022_exit(void)
317	{
318	i2c_del_driver(&isl12022_driver);
319	}
320
321	module_init(isl12022_init);
322	module_exit(isl12022_exit);
323
324	MODULE_AUTHOR("roman.fietze@telemotive.de");
325	MODULE_DESCRIPTION("ISL 12022 RTC driver");
326	MODULE_LICENSE("GPL");
327	MODULE_VERSION(DRV_VERSION);