[deliverable/linux.git] / drivers / rtc / rtc-s35390a.c

/*
 * Seiko Instruments S-35390A RTC Driver
 *
 * Copyright (c) 2007 Byron Bradley
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/i2c.h>
#include <linux/bitrev.h>
#include <linux/bcd.h>
#include <linux/slab.h>

#define S35390A_CMD_STATUS1	0
#define S35390A_CMD_STATUS2	1
#define S35390A_CMD_TIME1	2

#define S35390A_BYTE_YEAR	0
#define S35390A_BYTE_MONTH	1
#define S35390A_BYTE_DAY	2
#define S35390A_BYTE_WDAY	3
#define S35390A_BYTE_HOURS	4
#define S35390A_BYTE_MINS	5
#define S35390A_BYTE_SECS	6

#define S35390A_FLAG_POC	0x01
#define S35390A_FLAG_BLD	0x02
#define S35390A_FLAG_24H	0x40
#define S35390A_FLAG_RESET	0x80
#define S35390A_FLAG_TEST	0x01

static const struct i2c_device_id s35390a_id[] = {
	{ "s35390a", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, s35390a_id);

struct s35390a {
	struct i2c_client *client[8];
	struct rtc_device *rtc;
	int twentyfourhour;
};

static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
{
	struct i2c_client *client = s35390a->client[reg];
	struct i2c_msg msg[] = {
		{
			.addr = client->addr,
			.len = len,
			.buf = buf
		},
	};

	if ((i2c_transfer(client->adapter, msg, 1)) != 1)
		return -EIO;

	return 0;
}

static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
{
	struct i2c_client *client = s35390a->client[reg];
	struct i2c_msg msg[] = {
		{
			.addr = client->addr,
			.flags = I2C_M_RD,
			.len = len,
			.buf = buf
		},
	};

	if ((i2c_transfer(client->adapter, msg, 1)) != 1)
		return -EIO;

	return 0;
}

static int s35390a_reset(struct s35390a *s35390a)
{
	char buf[1];

	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0)
		return -EIO;

	if (!(buf[0] & (S35390A_FLAG_POC | S35390A_FLAG_BLD)))
		return 0;

	buf[0] |= (S35390A_FLAG_RESET | S35390A_FLAG_24H);
	buf[0] &= 0xf0;
	return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
}

static int s35390a_disable_test_mode(struct s35390a *s35390a)
{
	char buf[1];

	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
		return -EIO;

	if (!(buf[0] & S35390A_FLAG_TEST))
		return 0;

	buf[0] &= ~S35390A_FLAG_TEST;
	return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
}

static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
{
	if (s35390a->twentyfourhour)
		return bin2bcd(hour);

	if (hour < 12)
		return bin2bcd(hour);

	return 0x40 | bin2bcd(hour - 12);
}

static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
{
	unsigned hour;

	if (s35390a->twentyfourhour)
		return bcd2bin(reg & 0x3f);

	hour = bcd2bin(reg & 0x3f);
	if (reg & 0x40)
		hour += 12;

	return hour;
}

static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	struct s35390a	*s35390a = i2c_get_clientdata(client);
	int i, err;
	char buf[7];

	dev_dbg(&client->dev, "%s: tm is 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);

	buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
	buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
	buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
	buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
	buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
	buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
	buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);

	/* This chip expects the bits of each byte to be in reverse order */
	for (i = 0; i < 7; ++i)
		buf[i] = bitrev8(buf[i]);

	err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));

	return err;
}

static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	struct s35390a *s35390a = i2c_get_clientdata(client);
	char buf[7];
	int i, err;

	err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
	if (err < 0)
		return err;

	/* This chip returns the bits of each byte in reverse order */
	for (i = 0; i < 7; ++i)
		buf[i] = bitrev8(buf[i]);

	tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
	tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
	tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
	tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
	tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
	tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
	tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;

	dev_dbg(&client->dev, "%s: tm is 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 s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return s35390a_get_datetime(to_i2c_client(dev), tm);
}

static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return s35390a_set_datetime(to_i2c_client(dev), tm);
}

static const struct rtc_class_ops s35390a_rtc_ops = {
	.read_time	= s35390a_rtc_read_time,
	.set_time	= s35390a_rtc_set_time,
};

static struct i2c_driver s35390a_driver;

static int s35390a_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	int err;
	unsigned int i;
	struct s35390a *s35390a;
	struct rtc_time tm;
	char buf[1];

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		err = -ENODEV;
		goto exit;
	}

	s35390a = kzalloc(sizeof(struct s35390a), GFP_KERNEL);
	if (!s35390a) {
		err = -ENOMEM;
		goto exit;
	}

	s35390a->client[0] = client;
	i2c_set_clientdata(client, s35390a);

	/* This chip uses multiple addresses, use dummy devices for them */
	for (i = 1; i < 8; ++i) {
		s35390a->client[i] = i2c_new_dummy(client->adapter,
					client->addr + i);
		if (!s35390a->client[i]) {
			dev_err(&client->dev, "Address %02x unavailable\n",
						client->addr + i);
			err = -EBUSY;
			goto exit_dummy;
		}
	}

	err = s35390a_reset(s35390a);
	if (err < 0) {
		dev_err(&client->dev, "error resetting chip\n");
		goto exit_dummy;
	}

	err = s35390a_disable_test_mode(s35390a);
	if (err < 0) {
		dev_err(&client->dev, "error disabling test mode\n");
		goto exit_dummy;
	}

	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
	if (err < 0) {
		dev_err(&client->dev, "error checking 12/24 hour mode\n");
		goto exit_dummy;
	}
	if (buf[0] & S35390A_FLAG_24H)
		s35390a->twentyfourhour = 1;
	else
		s35390a->twentyfourhour = 0;

	if (s35390a_get_datetime(client, &tm) < 0)
		dev_warn(&client->dev, "clock needs to be set\n");

	s35390a->rtc = rtc_device_register(s35390a_driver.driver.name,
				&client->dev, &s35390a_rtc_ops, THIS_MODULE);

	if (IS_ERR(s35390a->rtc)) {
		err = PTR_ERR(s35390a->rtc);
		goto exit_dummy;
	}
	return 0;

exit_dummy:
	for (i = 1; i < 8; ++i)
		if (s35390a->client[i])
			i2c_unregister_device(s35390a->client[i]);
	kfree(s35390a);

exit:
	return err;
}

static int s35390a_remove(struct i2c_client *client)
{
	unsigned int i;

	struct s35390a *s35390a = i2c_get_clientdata(client);
	for (i = 1; i < 8; ++i)
		if (s35390a->client[i])
			i2c_unregister_device(s35390a->client[i]);

	rtc_device_unregister(s35390a->rtc);
	kfree(s35390a);

	return 0;
}

static struct i2c_driver s35390a_driver = {
	.driver		= {
		.name	= "rtc-s35390a",
	},
	.probe		= s35390a_probe,
	.remove		= s35390a_remove,
	.id_table	= s35390a_id,
};

module_i2c_driver(s35390a_driver);

MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
MODULE_DESCRIPTION("S35390A RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
c46288b0 BB	1	/*
	2	* Seiko Instruments S-35390A RTC Driver
	3	*
	4	* Copyright (c) 2007 Byron Bradley
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/rtc.h>
	14	#include <linux/i2c.h>
	15	#include <linux/bitrev.h>
	16	#include <linux/bcd.h>
	17	#include <linux/slab.h>
	18
	19	#define S35390A_CMD_STATUS1 0
	20	#define S35390A_CMD_STATUS2 1
	21	#define S35390A_CMD_TIME1 2
	22
	23	#define S35390A_BYTE_YEAR 0
	24	#define S35390A_BYTE_MONTH 1
	25	#define S35390A_BYTE_DAY 2
	26	#define S35390A_BYTE_WDAY 3
	27	#define S35390A_BYTE_HOURS 4
	28	#define S35390A_BYTE_MINS 5
	29	#define S35390A_BYTE_SECS 6
	30
	31	#define S35390A_FLAG_POC 0x01
	32	#define S35390A_FLAG_BLD 0x02
	33	#define S35390A_FLAG_24H 0x40
	34	#define S35390A_FLAG_RESET 0x80
	35	#define S35390A_FLAG_TEST 0x01
	36
3760f736 JD	37	static const struct i2c_device_id s35390a_id[] = {
	38	{ "s35390a", 0 },
	39	{ }
	40	};
	41	MODULE_DEVICE_TABLE(i2c, s35390a_id);
	42
c46288b0 BB	43	struct s35390a {
	44	struct i2c_client *client[8];
	45	struct rtc_device *rtc;
	46	int twentyfourhour;
	47	};
	48
	49	static int s35390a_set_reg(struct s35390a s35390a, int reg, char buf, int len)
	50	{
	51	struct i2c_client *client = s35390a->client[reg];
	52	struct i2c_msg msg[] = {
65659f63 S	53	{
	54	.addr = client->addr,
	55	.len = len,
	56	.buf = buf
	57	},
c46288b0 BB	58	};
	59
	60	if ((i2c_transfer(client->adapter, msg, 1)) != 1)
	61	return -EIO;
	62
	63	return 0;
	64	}
	65
	66	static int s35390a_get_reg(struct s35390a s35390a, int reg, char buf, int len)
	67	{
	68	struct i2c_client *client = s35390a->client[reg];
	69	struct i2c_msg msg[] = {
65659f63 S	70	{
	71	.addr = client->addr,
	72	.flags = I2C_M_RD,
	73	.len = len,
	74	.buf = buf
	75	},
c46288b0 BB	76	};
	77
	78	if ((i2c_transfer(client->adapter, msg, 1)) != 1)
	79	return -EIO;
	80
	81	return 0;
	82	}
	83
	84	static int s35390a_reset(struct s35390a *s35390a)
	85	{
	86	char buf[1];
	87
	88	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0)
	89	return -EIO;
	90
	91	if (!(buf[0] & (S35390A_FLAG_POC \| S35390A_FLAG_BLD)))
	92	return 0;
	93
	94	buf[0] \|= (S35390A_FLAG_RESET \| S35390A_FLAG_24H);
	95	buf[0] &= 0xf0;
	96	return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
	97	}
	98
	99	static int s35390a_disable_test_mode(struct s35390a *s35390a)
	100	{
	101	char buf[1];
	102
	103	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
	104	return -EIO;
	105
	106	if (!(buf[0] & S35390A_FLAG_TEST))
	107	return 0;
	108
	109	buf[0] &= ~S35390A_FLAG_TEST;
	110	return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
	111	}
	112
	113	static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
	114	{
	115	if (s35390a->twentyfourhour)
fe20ba70	116	return bin2bcd(hour);
c46288b0 BB	117
c46288b0 BB	118	if (hour < 12)
fe20ba70	119	return bin2bcd(hour);
c46288b0	120
fe20ba70	121	return 0x40 \| bin2bcd(hour - 12);
c46288b0 BB	122	}
	123
	124	static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
	125	{
	126	unsigned hour;
	127
	128	if (s35390a->twentyfourhour)
fe20ba70	129	return bcd2bin(reg & 0x3f);
c46288b0	130
fe20ba70	131	hour = bcd2bin(reg & 0x3f);
c46288b0 BB	132	if (reg & 0x40)
	133	hour += 12;
	134
	135	return hour;
	136	}
	137
	138	static int s35390a_set_datetime(struct i2c_client client, struct rtc_time tm)
	139	{
	140	struct s35390a *s35390a = i2c_get_clientdata(client);
	141	int i, err;
	142	char buf[7];
	143
	144	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
	145	"mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
	146	tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
	147	tm->tm_wday);
	148
fe20ba70 AB	149	buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
	150	buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
	151	buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
	152	buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
c46288b0	153	buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
fe20ba70 AB	154	buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
fe20ba70 AB	155	buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
c46288b0 BB	156
	157	/* This chip expects the bits of each byte to be in reverse order */
	158	for (i = 0; i < 7; ++i)
	159	buf[i] = bitrev8(buf[i]);
	160
	161	err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
	162
	163	return err;
	164	}
	165
	166	static int s35390a_get_datetime(struct i2c_client client, struct rtc_time tm)
	167	{
	168	struct s35390a *s35390a = i2c_get_clientdata(client);
	169	char buf[7];
	170	int i, err;
	171
	172	err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
	173	if (err < 0)
	174	return err;
	175
	176	/* This chip returns the bits of each byte in reverse order */
	177	for (i = 0; i < 7; ++i)
	178	buf[i] = bitrev8(buf[i]);
	179
fe20ba70 AB	180	tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
fe20ba70 AB	181	tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
c46288b0	182	tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
fe20ba70 AB	183	tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
	184	tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
	185	tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
	186	tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
c46288b0 BB	187
	188	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
	189	"mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
	190	tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
	191	tm->tm_wday);
	192
	193	return rtc_valid_tm(tm);
	194	}
	195
	196	static int s35390a_rtc_read_time(struct device dev, struct rtc_time tm)
	197	{
	198	return s35390a_get_datetime(to_i2c_client(dev), tm);
	199	}
	200
	201	static int s35390a_rtc_set_time(struct device dev, struct rtc_time tm)
	202	{
	203	return s35390a_set_datetime(to_i2c_client(dev), tm);
	204	}
	205
	206	static const struct rtc_class_ops s35390a_rtc_ops = {
	207	.read_time = s35390a_rtc_read_time,
	208	.set_time = s35390a_rtc_set_time,
	209	};
	210
	211	static struct i2c_driver s35390a_driver;
	212
d2653e92 JD	213	static int s35390a_probe(struct i2c_client *client,
d2653e92 JD	214	const struct i2c_device_id *id)
c46288b0 BB	215	{
	216	int err;
	217	unsigned int i;
	218	struct s35390a *s35390a;
	219	struct rtc_time tm;
	220	char buf[1];
	221
	222	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
	223	err = -ENODEV;
	224	goto exit;
	225	}
	226
	227	s35390a = kzalloc(sizeof(struct s35390a), GFP_KERNEL);
	228	if (!s35390a) {
	229	err = -ENOMEM;
	230	goto exit;
	231	}
	232
	233	s35390a->client[0] = client;
	234	i2c_set_clientdata(client, s35390a);
	235
	236	/* This chip uses multiple addresses, use dummy devices for them */
	237	for (i = 1; i < 8; ++i) {
	238	s35390a->client[i] = i2c_new_dummy(client->adapter,
60b129d7	239	client->addr + i);
c46288b0 BB	240	if (!s35390a->client[i]) {
	241	dev_err(&client->dev, "Address %02x unavailable\n",
	242	client->addr + i);
	243	err = -EBUSY;
	244	goto exit_dummy;
	245	}
	246	}
	247
	248	err = s35390a_reset(s35390a);
	249	if (err < 0) {
	250	dev_err(&client->dev, "error resetting chip\n");
	251	goto exit_dummy;
	252	}
	253
	254	err = s35390a_disable_test_mode(s35390a);
	255	if (err < 0) {
	256	dev_err(&client->dev, "error disabling test mode\n");
	257	goto exit_dummy;
	258	}
	259
	260	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
	261	if (err < 0) {
	262	dev_err(&client->dev, "error checking 12/24 hour mode\n");
	263	goto exit_dummy;
	264	}
	265	if (buf[0] & S35390A_FLAG_24H)
	266	s35390a->twentyfourhour = 1;
	267	else
	268	s35390a->twentyfourhour = 0;
	269
	270	if (s35390a_get_datetime(client, &tm) < 0)
	271	dev_warn(&client->dev, "clock needs to be set\n");
	272
	273	s35390a->rtc = rtc_device_register(s35390a_driver.driver.name,
	274	&client->dev, &s35390a_rtc_ops, THIS_MODULE);
	275
	276	if (IS_ERR(s35390a->rtc)) {
	277	err = PTR_ERR(s35390a->rtc);
	278	goto exit_dummy;
	279	}
	280	return 0;
	281
	282	exit_dummy:
	283	for (i = 1; i < 8; ++i)
	284	if (s35390a->client[i])
	285	i2c_unregister_device(s35390a->client[i]);
	286	kfree(s35390a);
c46288b0 BB	287
	288	exit:
	289	return err;
	290	}
	291
	292	static int s35390a_remove(struct i2c_client *client)
	293	{
	294	unsigned int i;
	295
	296	struct s35390a *s35390a = i2c_get_clientdata(client);
	297	for (i = 1; i < 8; ++i)
	298	if (s35390a->client[i])
	299	i2c_unregister_device(s35390a->client[i]);
	300
	301	rtc_device_unregister(s35390a->rtc);
	302	kfree(s35390a);
c46288b0 BB	303
	304	return 0;
	305	}
	306
	307	static struct i2c_driver s35390a_driver = {
	308	.driver = {
	309	.name = "rtc-s35390a",
	310	},
	311	.probe = s35390a_probe,
	312	.remove = s35390a_remove,
3760f736	313	.id_table = s35390a_id,
c46288b0 BB	314	};
c46288b0 BB	315
0abc9201	316	module_i2c_driver(s35390a_driver);
c46288b0 BB	317
	318	MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
	319	MODULE_DESCRIPTION("S35390A RTC driver");
	320	MODULE_LICENSE("GPL");