[deliverable/linux.git] / drivers / rtc / rtc-pcf8563.c

/*
 * An I2C driver for the Philips PCF8563 RTC
 * Copyright 2005-06 Tower Technologies
 *
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 * Maintainers: http://www.nslu2-linux.org/
 *
 * based on the other drivers in this same directory.
 *
 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
 *
 * 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>

#define DRV_VERSION "0.4.3"

#define PCF8563_REG_ST1		0x00 /* status */
#define PCF8563_REG_ST2		0x01

#define PCF8563_REG_SC		0x02 /* datetime */
#define PCF8563_REG_MN		0x03
#define PCF8563_REG_HR		0x04
#define PCF8563_REG_DM		0x05
#define PCF8563_REG_DW		0x06
#define PCF8563_REG_MO		0x07
#define PCF8563_REG_YR		0x08

#define PCF8563_REG_AMN		0x09 /* alarm */
#define PCF8563_REG_AHR		0x0A
#define PCF8563_REG_ADM		0x0B
#define PCF8563_REG_ADW		0x0C

#define PCF8563_REG_CLKO	0x0D /* clock out */
#define PCF8563_REG_TMRC	0x0E /* timer control */
#define PCF8563_REG_TMR		0x0F /* timer */

#define PCF8563_SC_LV		0x80 /* low voltage */
#define PCF8563_MO_C		0x80 /* century */

static struct i2c_driver pcf8563_driver;

struct pcf8563 {
	struct rtc_device *rtc;
	/*
	 * The meaning of MO_C bit varies by the chip type.
	 * From PCF8563 datasheet: this bit is toggled when the years
	 * register overflows from 99 to 00
	 *   0 indicates the century is 20xx
	 *   1 indicates the century is 19xx
	 * From RTC8564 datasheet: this bit indicates change of
	 * century. When the year digit data overflows from 99 to 00,
	 * this bit is set. By presetting it to 0 while still in the
	 * 20th century, it will be set in year 2000, ...
	 * There seems no reliable way to know how the system use this
	 * bit.  So let's do it heuristically, assuming we are live in
	 * 1970...2069.
	 */
	int c_polarity;	/* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
};

/*
 * In the routines that deal directly with the pcf8563 hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
 */
static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
	unsigned char buf[13] = { PCF8563_REG_ST1 };

	struct i2c_msg msgs[] = {
		{ client->addr, 0, 1, buf },	/* setup read ptr */
		{ client->addr, I2C_M_RD, 13, buf },	/* read status + date */
	};

	/* read registers */
	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
		dev_err(&client->dev, "%s: read error\n", __func__);
		return -EIO;
	}

	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
		dev_info(&client->dev,
			"low voltage detected, date/time is not reliable.\n");

	dev_dbg(&client->dev,
		"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
		"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
		__func__,
		buf[0], buf[1], buf[2], buf[3],
		buf[4], buf[5], buf[6], buf[7],
		buf[8]);


	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
	if (tm->tm_year < 70)
		tm->tm_year += 100;	/* assume we are in 1970...2069 */
	/* detect the polarity heuristically. see note above. */
	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
		(tm->tm_year >= 100) : (tm->tm_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);

	/* 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/time is not valid.\n");

	return 0;
}

static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
	int i, err;
	unsigned char buf[9];

	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);

	/* hours, minutes and seconds */
	buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);

	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);

	/* month, 1 - 12 */
	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);

	/* year and century */
	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
		buf[PCF8563_REG_MO] |= PCF8563_MO_C;

	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;

	/* write register's data */
	for (i = 0; i < 7; i++) {
		unsigned char data[2] = { PCF8563_REG_SC + i,
						buf[PCF8563_REG_SC + i] };

		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;
}

static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return pcf8563_get_datetime(to_i2c_client(dev), tm);
}

static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return pcf8563_set_datetime(to_i2c_client(dev), tm);
}

static const struct rtc_class_ops pcf8563_rtc_ops = {
	.read_time	= pcf8563_rtc_read_time,
	.set_time	= pcf8563_rtc_set_time,
};

static int pcf8563_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct pcf8563 *pcf8563;

	int err = 0;

	dev_dbg(&client->dev, "%s\n", __func__);

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

	pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
	if (!pcf8563)
		return -ENOMEM;

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

	i2c_set_clientdata(client, pcf8563);

	pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
				&client->dev, &pcf8563_rtc_ops, THIS_MODULE);

	if (IS_ERR(pcf8563->rtc)) {
		err = PTR_ERR(pcf8563->rtc);
		goto exit_kfree;
	}

	return 0;

exit_kfree:
	kfree(pcf8563);

	return err;
}

static int pcf8563_remove(struct i2c_client *client)
{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);

	if (pcf8563->rtc)
		rtc_device_unregister(pcf8563->rtc);

	kfree(pcf8563);

	return 0;
}

static const struct i2c_device_id pcf8563_id[] = {
	{ "pcf8563", 0 },
	{ "rtc8564", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pcf8563_id);

static struct i2c_driver pcf8563_driver = {
	.driver		= {
		.name	= "rtc-pcf8563",
	},
	.probe		= pcf8563_probe,
	.remove		= pcf8563_remove,
	.id_table	= pcf8563_id,
};

module_i2c_driver(pcf8563_driver);

MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
Commit	Line	Data
b5a82d62 AZ	1	/*
	2	* An I2C driver for the Philips PCF8563 RTC
	3	* Copyright 2005-06 Tower Technologies
	4	*
	5	* Author: Alessandro Zummo <a.zummo@towertech.it>
	6	* Maintainers: http://www.nslu2-linux.org/
	7	*
	8	* based on the other drivers in this same directory.
	9	*
	10	* http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*/
	16
	17	#include <linux/i2c.h>
	18	#include <linux/bcd.h>
	19	#include <linux/rtc.h>
5a0e3ad6	20	#include <linux/slab.h>
2113852b	21	#include <linux/module.h>
b5a82d62	22
e5fc9cc0	23	#define DRV_VERSION "0.4.3"
b5a82d62 AZ	24
	25	#define PCF8563_REG_ST1 0x00 /* status */
	26	#define PCF8563_REG_ST2 0x01
	27
	28	#define PCF8563_REG_SC 0x02 /* datetime */
	29	#define PCF8563_REG_MN 0x03
	30	#define PCF8563_REG_HR 0x04
	31	#define PCF8563_REG_DM 0x05
	32	#define PCF8563_REG_DW 0x06
	33	#define PCF8563_REG_MO 0x07
	34	#define PCF8563_REG_YR 0x08
	35
	36	#define PCF8563_REG_AMN 0x09 /* alarm */
	37	#define PCF8563_REG_AHR 0x0A
	38	#define PCF8563_REG_ADM 0x0B
	39	#define PCF8563_REG_ADW 0x0C
	40
	41	#define PCF8563_REG_CLKO 0x0D /* clock out */
	42	#define PCF8563_REG_TMRC 0x0E /* timer control */
	43	#define PCF8563_REG_TMR 0x0F /* timer */
	44
	45	#define PCF8563_SC_LV 0x80 /* low voltage */
	46	#define PCF8563_MO_C 0x80 /* century */
	47
e5fc9cc0 AZ	48	static struct i2c_driver pcf8563_driver;
e5fc9cc0 AZ	49
cbb94502	50	struct pcf8563 {
e5fc9cc0	51	struct rtc_device *rtc;
cbb94502 AN	52	/*
	53	* The meaning of MO_C bit varies by the chip type.
	54	* From PCF8563 datasheet: this bit is toggled when the years
	55	* register overflows from 99 to 00
	56	* 0 indicates the century is 20xx
	57	* 1 indicates the century is 19xx
	58	* From RTC8564 datasheet: this bit indicates change of
	59	* century. When the year digit data overflows from 99 to 00,
	60	* this bit is set. By presetting it to 0 while still in the
	61	* 20th century, it will be set in year 2000, ...
	62	* There seems no reliable way to know how the system use this
	63	* bit. So let's do it heuristically, assuming we are live in
	64	* 1970...2069.
	65	*/
	66	int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
	67	};
	68
b5a82d62 AZ	69	/*
	70	* In the routines that deal directly with the pcf8563 hardware, we use
	71	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	72	*/
	73	static int pcf8563_get_datetime(struct i2c_client client, struct rtc_time tm)
	74	{
e5fc9cc0	75	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
b5a82d62 AZ	76	unsigned char buf[13] = { PCF8563_REG_ST1 };
	77
	78	struct i2c_msg msgs[] = {
	79	{ client->addr, 0, 1, buf }, /* setup read ptr */
	80	{ client->addr, I2C_M_RD, 13, buf }, /* read status + date */
	81	};
	82
	83	/* read registers */
	84	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
2a4e2b87	85	dev_err(&client->dev, "%s: read error\n", __func__);
b5a82d62 AZ	86	return -EIO;
	87	}
	88
	89	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
	90	dev_info(&client->dev,
	91	"low voltage detected, date/time is not reliable.\n");
	92
	93	dev_dbg(&client->dev,
	94	"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
	95	"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
2a4e2b87	96	__func__,
b5a82d62 AZ	97	buf[0], buf[1], buf[2], buf[3],
	98	buf[4], buf[5], buf[6], buf[7],
	99	buf[8]);
	100
	101
fe20ba70 AB	102	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
	103	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
	104	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
	105	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
b5a82d62	106	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
fe20ba70 AB	107	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
fe20ba70 AB	108	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
cbb94502 AN	109	if (tm->tm_year < 70)
	110	tm->tm_year += 100; /* assume we are in 1970...2069 */
	111	/* detect the polarity heuristically. see note above. */
	112	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
	113	(tm->tm_year >= 100) : (tm->tm_year < 100);
b5a82d62 AZ	114
	115	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	116	"mday=%d, mon=%d, year=%d, wday=%d\n",
2a4e2b87	117	__func__,
b5a82d62 AZ	118	tm->tm_sec, tm->tm_min, tm->tm_hour,
	119	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	120
	121	/* the clock can give out invalid datetime, but we cannot return
	122	* -EINVAL otherwise hwclock will refuse to set the time on bootup.
	123	*/
	124	if (rtc_valid_tm(tm) < 0)
	125	dev_err(&client->dev, "retrieved date/time is not valid.\n");
	126
	127	return 0;
	128	}
	129
	130	static int pcf8563_set_datetime(struct i2c_client client, struct rtc_time tm)
	131	{
e5fc9cc0	132	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
b5a82d62 AZ	133	int i, err;
	134	unsigned char buf[9];
	135
	136	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	137	"mday=%d, mon=%d, year=%d, wday=%d\n",
2a4e2b87	138	__func__,
b5a82d62 AZ	139	tm->tm_sec, tm->tm_min, tm->tm_hour,
	140	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	141
	142	/* hours, minutes and seconds */
fe20ba70 AB	143	buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
	144	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
	145	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
b5a82d62	146
fe20ba70	147	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
b5a82d62 AZ	148
b5a82d62 AZ	149	/* month, 1 - 12 */
fe20ba70	150	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
b5a82d62 AZ	151
b5a82d62 AZ	152	/* year and century */
fe20ba70	153	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
cbb94502	154	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
b5a82d62 AZ	155	buf[PCF8563_REG_MO] \|= PCF8563_MO_C;
	156
	157	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
	158
	159	/* write register's data */
	160	for (i = 0; i < 7; i++) {
	161	unsigned char data[2] = { PCF8563_REG_SC + i,
	162	buf[PCF8563_REG_SC + i] };
	163
	164	err = i2c_master_send(client, data, sizeof(data));
	165	if (err != sizeof(data)) {
	166	dev_err(&client->dev,
	167	"%s: err=%d addr=%02x, data=%02x\n",
2a4e2b87	168	__func__, err, data[0], data[1]);
b5a82d62 AZ	169	return -EIO;
	170	}
	171	};
	172
	173	return 0;
	174	}
	175
b5a82d62 AZ	176	static int pcf8563_rtc_read_time(struct device dev, struct rtc_time tm)
	177	{
	178	return pcf8563_get_datetime(to_i2c_client(dev), tm);
	179	}
	180
	181	static int pcf8563_rtc_set_time(struct device dev, struct rtc_time tm)
	182	{
	183	return pcf8563_set_datetime(to_i2c_client(dev), tm);
	184	}
	185
ff8371ac	186	static const struct rtc_class_ops pcf8563_rtc_ops = {
b5a82d62 AZ	187	.read_time = pcf8563_rtc_read_time,
	188	.set_time = pcf8563_rtc_set_time,
	189	};
	190
d2653e92 JD	191	static int pcf8563_probe(struct i2c_client *client,
d2653e92 JD	192	const struct i2c_device_id *id)
b5a82d62	193	{
cbb94502	194	struct pcf8563 *pcf8563;
b5a82d62 AZ	195
	196	int err = 0;
	197
e5fc9cc0	198	dev_dbg(&client->dev, "%s\n", __func__);
b5a82d62	199
e5fc9cc0 AZ	200	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
e5fc9cc0 AZ	201	return -ENODEV;
b5a82d62	202
e5fc9cc0 AZ	203	pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
	204	if (!pcf8563)
	205	return -ENOMEM;
b5a82d62	206
b5a82d62 AZ	207	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
b5a82d62 AZ	208
b74d2caa AZ	209	i2c_set_clientdata(client, pcf8563);
b74d2caa AZ	210
e5fc9cc0 AZ	211	pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
e5fc9cc0 AZ	212	&client->dev, &pcf8563_rtc_ops, THIS_MODULE);
b5a82d62	213
e5fc9cc0 AZ	214	if (IS_ERR(pcf8563->rtc)) {
	215	err = PTR_ERR(pcf8563->rtc);
	216	goto exit_kfree;
b5a82d62 AZ	217	}
b5a82d62 AZ	218
b5a82d62 AZ	219	return 0;
b5a82d62 AZ	220
b5a82d62	221	exit_kfree:
cbb94502	222	kfree(pcf8563);
b5a82d62	223
b5a82d62 AZ	224	return err;
	225	}
	226
e5fc9cc0	227	static int pcf8563_remove(struct i2c_client *client)
b5a82d62	228	{
e5fc9cc0	229	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
b5a82d62	230
e5fc9cc0 AZ	231	if (pcf8563->rtc)
e5fc9cc0 AZ	232	rtc_device_unregister(pcf8563->rtc);
b5a82d62	233
cbb94502	234	kfree(pcf8563);
b5a82d62 AZ	235
	236	return 0;
	237	}
	238
3760f736 JD	239	static const struct i2c_device_id pcf8563_id[] = {
3760f736 JD	240	{ "pcf8563", 0 },
8ea9212c	241	{ "rtc8564", 0 },
3760f736 JD	242	{ }
	243	};
	244	MODULE_DEVICE_TABLE(i2c, pcf8563_id);
	245
e5fc9cc0 AZ	246	static struct i2c_driver pcf8563_driver = {
	247	.driver = {
	248	.name = "rtc-pcf8563",
	249	},
	250	.probe = pcf8563_probe,
	251	.remove = pcf8563_remove,
3760f736	252	.id_table = pcf8563_id,
e5fc9cc0 AZ	253	};
e5fc9cc0 AZ	254
0abc9201	255	module_i2c_driver(pcf8563_driver);
b5a82d62 AZ	256
	257	MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
	258	MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
	259	MODULE_LICENSE("GPL");
	260	MODULE_VERSION(DRV_VERSION);