[mirror_ubuntu-artful-kernel.git] / drivers / rtc / rtc-pcf2127.c

/*
 * An I2C driver for the NXP PCF2127 RTC
 * Copyright 2013 Til-Technologies
 *
 * Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
 *
 * based on the other drivers in this same directory.
 *
 * http://www.nxp.com/documents/data_sheet/PCF2127AT.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>
#include <linux/of.h>

#define PCF2127_REG_CTRL1       (0x00)  /* Control Register 1 */
#define PCF2127_REG_CTRL2       (0x01)  /* Control Register 2 */

#define PCF2127_REG_CTRL3       (0x02)  /* Control Register 3 */
#define PCF2127_REG_CTRL3_BLF		BIT(2)

#define PCF2127_REG_SC          (0x03)  /* datetime */
#define PCF2127_REG_MN          (0x04)
#define PCF2127_REG_HR          (0x05)
#define PCF2127_REG_DM          (0x06)
#define PCF2127_REG_DW          (0x07)
#define PCF2127_REG_MO          (0x08)
#define PCF2127_REG_YR          (0x09)

#define PCF2127_OSF             BIT(7)  /* Oscillator Fail flag */

static struct i2c_driver pcf2127_driver;

struct pcf2127 {
	struct rtc_device *rtc;
};

/*
 * In the routines that deal directly with the pcf2127 hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
 */
static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	unsigned char buf[10] = { PCF2127_REG_CTRL1 };

	/* read registers */
	if (i2c_master_send(client, buf, 1) != 1 ||
		i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
		dev_err(&client->dev, "%s: read error\n", __func__);
		return -EIO;
	}

	if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF)
		dev_info(&client->dev,
			"low voltage detected, check/replace RTC battery.\n");

	if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
		/*
		 * no need clear the flag here,
		 * it will be cleared once the new date is saved
		 */
		dev_warn(&client->dev,
			 "oscillator stop detected, date/time is not reliable\n");
		return -EINVAL;
	}

	dev_dbg(&client->dev,
		"%s: raw data is cr1=%02x, cr2=%02x, cr3=%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], buf[9]);


	tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
	tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
	tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
	tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
	if (tm->tm_year < 70)
		tm->tm_year += 100;	/* assume we are in 1970...2069 */

	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 pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	unsigned char buf[8];
	int i = 0, err;

	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);

	/* start register address */
	buf[i++] = PCF2127_REG_SC;

	/* hours, minutes and seconds */
	buf[i++] = bin2bcd(tm->tm_sec);	/* this will also clear OSF flag */
	buf[i++] = bin2bcd(tm->tm_min);
	buf[i++] = bin2bcd(tm->tm_hour);
	buf[i++] = bin2bcd(tm->tm_mday);
	buf[i++] = tm->tm_wday & 0x07;

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

	/* year */
	buf[i++] = bin2bcd(tm->tm_year % 100);

	/* write register's data */
	err = i2c_master_send(client, buf, i);
	if (err != i) {
		dev_err(&client->dev,
			"%s: err=%d", __func__, err);
		return -EIO;
	}

	return 0;
}

#ifdef CONFIG_RTC_INTF_DEV
static int pcf2127_rtc_ioctl(struct device *dev,
				unsigned int cmd, unsigned long arg)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf = PCF2127_REG_CTRL3;
	int touser;
	int ret;

	switch (cmd) {
	case RTC_VL_READ:
		ret = i2c_master_send(client, &buf, 1);
		if (!ret)
			ret = -EIO;
		if (ret < 0)
			return ret;

		ret = i2c_master_recv(client, &buf, 1);
		if (!ret)
			ret = -EIO;
		if (ret < 0)
			return ret;

		touser = buf & PCF2127_REG_CTRL3_BLF ? 1 : 0;

		if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
			return -EFAULT;
		return 0;
	default:
		return -ENOIOCTLCMD;
	}
}
#else
#define pcf2127_rtc_ioctl NULL
#endif

static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return pcf2127_get_datetime(to_i2c_client(dev), tm);
}

static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return pcf2127_set_datetime(to_i2c_client(dev), tm);
}

static const struct rtc_class_ops pcf2127_rtc_ops = {
	.ioctl		= pcf2127_rtc_ioctl,
	.read_time	= pcf2127_rtc_read_time,
	.set_time	= pcf2127_rtc_set_time,
};

static int pcf2127_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct pcf2127 *pcf2127;

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

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

	pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
				GFP_KERNEL);
	if (!pcf2127)
		return -ENOMEM;

	i2c_set_clientdata(client, pcf2127);

	pcf2127->rtc = devm_rtc_device_register(&client->dev,
				pcf2127_driver.driver.name,
				&pcf2127_rtc_ops, THIS_MODULE);

	return PTR_ERR_OR_ZERO(pcf2127->rtc);
}

static const struct i2c_device_id pcf2127_id[] = {
	{ "pcf2127", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pcf2127_id);

#ifdef CONFIG_OF
static const struct of_device_id pcf2127_of_match[] = {
	{ .compatible = "nxp,pcf2127" },
	{}
};
MODULE_DEVICE_TABLE(of, pcf2127_of_match);
#endif

static struct i2c_driver pcf2127_driver = {
	.driver		= {
		.name	= "rtc-pcf2127",
		.of_match_table = of_match_ptr(pcf2127_of_match),
	},
	.probe		= pcf2127_probe,
	.id_table	= pcf2127_id,
};

module_i2c_driver(pcf2127_driver);

MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
18cb6368 RC	1	/*
	2	* An I2C driver for the NXP PCF2127 RTC
	3	* Copyright 2013 Til-Technologies
	4	*
	5	* Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
	6	*
	7	* based on the other drivers in this same directory.
	8	*
	9	* http://www.nxp.com/documents/data_sheet/PCF2127AT.pdf
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* published by the Free Software Foundation.
	14	*/
	15
	16	#include <linux/i2c.h>
	17	#include <linux/bcd.h>
	18	#include <linux/rtc.h>
	19	#include <linux/slab.h>
	20	#include <linux/module.h>
	21	#include <linux/of.h>
	22
18cb6368 RC	23	#define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */
18cb6368 RC	24	#define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */
f97cfddc	25
18cb6368	26	#define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */
f97cfddc UKK	27	#define PCF2127_REG_CTRL3_BLF BIT(2)
f97cfddc UKK	28
18cb6368 RC	29	#define PCF2127_REG_SC (0x03) /* datetime */
	30	#define PCF2127_REG_MN (0x04)
	31	#define PCF2127_REG_HR (0x05)
	32	#define PCF2127_REG_DM (0x06)
	33	#define PCF2127_REG_DW (0x07)
	34	#define PCF2127_REG_MO (0x08)
	35	#define PCF2127_REG_YR (0x09)
	36
653ebd75 AS	37	#define PCF2127_OSF BIT(7) /* Oscillator Fail flag */
653ebd75 AS	38
18cb6368 RC	39	static struct i2c_driver pcf2127_driver;
	40
	41	struct pcf2127 {
	42	struct rtc_device *rtc;
18cb6368 RC	43	};
	44
	45	/*
	46	* In the routines that deal directly with the pcf2127 hardware, we use
	47	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	48	*/
	49	static int pcf2127_get_datetime(struct i2c_client client, struct rtc_time tm)
	50	{
18cb6368 RC	51	unsigned char buf[10] = { PCF2127_REG_CTRL1 };
	52
	53	/* read registers */
	54	if (i2c_master_send(client, buf, 1) != 1 \|\|
	55	i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
	56	dev_err(&client->dev, "%s: read error\n", __func__);
	57	return -EIO;
	58	}
	59
f97cfddc	60	if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF)
18cb6368	61	dev_info(&client->dev,
653ebd75	62	"low voltage detected, check/replace RTC battery.\n");
653ebd75 AS	63
	64	if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
	65	/*
	66	* no need clear the flag here,
	67	* it will be cleared once the new date is saved
	68	*/
653ebd75 AS	69	dev_warn(&client->dev,
	70	"oscillator stop detected, date/time is not reliable\n");
	71	return -EINVAL;
18cb6368 RC	72	}
	73
	74	dev_dbg(&client->dev,
	75	"%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
	76	"sec=%02x, min=%02x, hr=%02x, "
	77	"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
	78	__func__,
	79	buf[0], buf[1], buf[2],
	80	buf[3], buf[4], buf[5],
	81	buf[6], buf[7], buf[8], buf[9]);
	82
	83
	84	tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
	85	tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
	86	tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
	87	tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
	88	tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
	89	tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	90	tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
	91	if (tm->tm_year < 70)
	92	tm->tm_year += 100; /* assume we are in 1970...2069 */
	93
	94	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	95	"mday=%d, mon=%d, year=%d, wday=%d\n",
	96	__func__,
	97	tm->tm_sec, tm->tm_min, tm->tm_hour,
	98	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	99
821f51c4	100	return rtc_valid_tm(tm);
18cb6368 RC	101	}
	102
	103	static int pcf2127_set_datetime(struct i2c_client client, struct rtc_time tm)
	104	{
	105	unsigned char buf[8];
	106	int i = 0, err;
	107
	108	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	109	"mday=%d, mon=%d, year=%d, wday=%d\n",
	110	__func__,
	111	tm->tm_sec, tm->tm_min, tm->tm_hour,
	112	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	113
	114	/* start register address */
	115	buf[i++] = PCF2127_REG_SC;
	116
	117	/* hours, minutes and seconds */
653ebd75	118	buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
18cb6368 RC	119	buf[i++] = bin2bcd(tm->tm_min);
	120	buf[i++] = bin2bcd(tm->tm_hour);
	121	buf[i++] = bin2bcd(tm->tm_mday);
	122	buf[i++] = tm->tm_wday & 0x07;
	123
	124	/* month, 1 - 12 */
	125	buf[i++] = bin2bcd(tm->tm_mon + 1);
	126
	127	/* year */
	128	buf[i++] = bin2bcd(tm->tm_year % 100);
	129
	130	/* write register's data */
	131	err = i2c_master_send(client, buf, i);
	132	if (err != i) {
	133	dev_err(&client->dev,
	134	"%s: err=%d", __func__, err);
	135	return -EIO;
	136	}
	137
	138	return 0;
	139	}
	140
	141	#ifdef CONFIG_RTC_INTF_DEV
	142	static int pcf2127_rtc_ioctl(struct device *dev,
	143	unsigned int cmd, unsigned long arg)
	144	{
f97cfddc UKK	145	struct i2c_client *client = to_i2c_client(dev);
	146	unsigned char buf = PCF2127_REG_CTRL3;
	147	int touser;
	148	int ret;
18cb6368 RC	149
	150	switch (cmd) {
	151	case RTC_VL_READ:
f97cfddc UKK	152	ret = i2c_master_send(client, &buf, 1);
	153	if (!ret)
	154	ret = -EIO;
	155	if (ret < 0)
	156	return ret;
	157
	158	ret = i2c_master_recv(client, &buf, 1);
	159	if (!ret)
	160	ret = -EIO;
	161	if (ret < 0)
	162	return ret;
	163
	164	touser = buf & PCF2127_REG_CTRL3_BLF ? 1 : 0;
18cb6368	165
f97cfddc	166	if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
18cb6368 RC	167	return -EFAULT;
	168	return 0;
	169	default:
	170	return -ENOIOCTLCMD;
	171	}
	172	}
	173	#else
	174	#define pcf2127_rtc_ioctl NULL
	175	#endif
	176
	177	static int pcf2127_rtc_read_time(struct device dev, struct rtc_time tm)
	178	{
	179	return pcf2127_get_datetime(to_i2c_client(dev), tm);
	180	}
	181
	182	static int pcf2127_rtc_set_time(struct device dev, struct rtc_time tm)
	183	{
	184	return pcf2127_set_datetime(to_i2c_client(dev), tm);
	185	}
	186
	187	static const struct rtc_class_ops pcf2127_rtc_ops = {
	188	.ioctl = pcf2127_rtc_ioctl,
	189	.read_time = pcf2127_rtc_read_time,
	190	.set_time = pcf2127_rtc_set_time,
	191	};
	192
	193	static int pcf2127_probe(struct i2c_client *client,
	194	const struct i2c_device_id *id)
	195	{
	196	struct pcf2127 *pcf2127;
	197
	198	dev_dbg(&client->dev, "%s\n", __func__);
	199
	200	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	201	return -ENODEV;
	202
	203	pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
	204	GFP_KERNEL);
	205	if (!pcf2127)
	206	return -ENOMEM;
	207
18cb6368 RC	208	i2c_set_clientdata(client, pcf2127);
	209
	210	pcf2127->rtc = devm_rtc_device_register(&client->dev,
	211	pcf2127_driver.driver.name,
	212	&pcf2127_rtc_ops, THIS_MODULE);
	213
7ab26cd1	214	return PTR_ERR_OR_ZERO(pcf2127->rtc);
18cb6368 RC	215	}
18cb6368 RC	216
18cb6368 RC	217	static const struct i2c_device_id pcf2127_id[] = {
	218	{ "pcf2127", 0 },
	219	{ }
	220	};
	221	MODULE_DEVICE_TABLE(i2c, pcf2127_id);
	222
	223	#ifdef CONFIG_OF
	224	static const struct of_device_id pcf2127_of_match[] = {
	225	{ .compatible = "nxp,pcf2127" },
	226	{}
	227	};
	228	MODULE_DEVICE_TABLE(of, pcf2127_of_match);
	229	#endif
	230
	231	static struct i2c_driver pcf2127_driver = {
	232	.driver = {
	233	.name = "rtc-pcf2127",
18cb6368 RC	234	.of_match_table = of_match_ptr(pcf2127_of_match),
	235	},
	236	.probe = pcf2127_probe,
18cb6368 RC	237	.id_table = pcf2127_id,
	238	};
	239
	240	module_i2c_driver(pcf2127_driver);
	241
	242	MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
	243	MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
4d8318bc	244	MODULE_LICENSE("GPL v2");