[linux.git] / drivers / rtc / rtc-ds1672.c

/*
 * An rtc/i2c driver for the Dallas DS1672
 * Copyright 2005-06 Tower Technologies
 *
 * Author: Alessandro Zummo <[email protected]>
 *
 * 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/module.h>
#include <linux/i2c.h>
#include <linux/rtc.h>

#define DRV_VERSION "0.3"

/* Addresses to scan: none. This chip cannot be detected. */
static unsigned short normal_i2c[] = { I2C_CLIENT_END };

/* Insmod parameters */
I2C_CLIENT_INSMOD;

/* Registers */

#define DS1672_REG_CNT_BASE	0
#define DS1672_REG_CONTROL	4
#define DS1672_REG_TRICKLE	5

#define DS1672_REG_CONTROL_EOSC	0x80

/* Prototypes */
static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind);

/*
 * In the routines that deal directly with the ds1672 hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
 * Epoch is initialized as 2000. Time is set to UTC.
 */
static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	unsigned long time;
	unsigned char addr = DS1672_REG_CNT_BASE;
	unsigned char buf[4];

	struct i2c_msg msgs[] = {
		{ client->addr, 0, 1, &addr },		/* setup read ptr */
		{ client->addr, I2C_M_RD, 4, buf },	/* read date */
	};

	/* read date registers */
	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
		return -EIO;
	}

	dev_dbg(&client->dev,
		"%s: raw read data - counters=%02x,%02x,%02x,%02x\n",
		__FUNCTION__, buf[0], buf[1], buf[2], buf[3]);

	time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];

	rtc_time_to_tm(time, tm);

	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	return 0;
}

static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs)
{
	int xfer;
	unsigned char buf[6];

	buf[0] = DS1672_REG_CNT_BASE;
	buf[1] = secs & 0x000000FF;
	buf[2] = (secs & 0x0000FF00) >> 8;
	buf[3] = (secs & 0x00FF0000) >> 16;
	buf[4] = (secs & 0xFF000000) >> 24;
	buf[5] = 0;	/* set control reg to enable counting */

	xfer = i2c_master_send(client, buf, 6);
	if (xfer != 6) {
		dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer);
		return -EIO;
	}

	return 0;
}

static int ds1672_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	unsigned long secs;

	dev_dbg(&client->dev,
		"%s: secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__FUNCTION__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	rtc_tm_to_time(tm, &secs);

	return ds1672_set_mmss(client, secs);
}

static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return ds1672_get_datetime(to_i2c_client(dev), tm);
}

static int ds1672_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return ds1672_set_datetime(to_i2c_client(dev), tm);
}

static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
{
	return ds1672_set_mmss(to_i2c_client(dev), secs);
}

static int ds1672_get_control(struct i2c_client *client, u8 *status)
{
	unsigned char addr = DS1672_REG_CONTROL;

	struct i2c_msg msgs[] = {
		{ client->addr, 0, 1, &addr },		/* setup read ptr */
		{ client->addr, I2C_M_RD, 1, status },	/* read control */
	};

	/* read control register */
	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
		return -EIO;
	}

	return 0;
}

/* following are the sysfs callback functions */
static ssize_t show_control(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	u8 control;
	int err;

	err = ds1672_get_control(client, &control);
	if (err)
		return err;

	return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC)
					? "disabled" : "enabled");
}
static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);

static const struct rtc_class_ops ds1672_rtc_ops = {
	.read_time	= ds1672_rtc_read_time,
	.set_time	= ds1672_rtc_set_time,
	.set_mmss	= ds1672_rtc_set_mmss,
};

static int ds1672_attach(struct i2c_adapter *adapter)
{
	return i2c_probe(adapter, &addr_data, ds1672_probe);
}

static int ds1672_detach(struct i2c_client *client)
{
	int err;
	struct rtc_device *rtc = i2c_get_clientdata(client);

 	if (rtc)
		rtc_device_unregister(rtc);

	if ((err = i2c_detach_client(client)))
		return err;

	kfree(client);

	return 0;
}

static struct i2c_driver ds1672_driver = {
	.driver		= {
		.name	= "ds1672",
	},
	.id		= I2C_DRIVERID_DS1672,
	.attach_adapter = &ds1672_attach,
	.detach_client	= &ds1672_detach,
};

static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind)
{
	int err = 0;
	u8 control;
	struct i2c_client *client;
	struct rtc_device *rtc;

	dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);

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

	if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
		err = -ENOMEM;
		goto exit;
	}

	/* I2C client */
	client->addr = address;
	client->driver = &ds1672_driver;
	client->adapter	= adapter;

	strlcpy(client->name, ds1672_driver.driver.name, I2C_NAME_SIZE);

	/* Inform the i2c layer */
	if ((err = i2c_attach_client(client)))
		goto exit_kfree;

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

	rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev,
				&ds1672_rtc_ops, THIS_MODULE);

	if (IS_ERR(rtc)) {
		err = PTR_ERR(rtc);
		goto exit_detach;
	}

	i2c_set_clientdata(client, rtc);

	/* read control register */
	err = ds1672_get_control(client, &control);
	if (err)
		goto exit_devreg;

	if (control & DS1672_REG_CONTROL_EOSC)
		dev_warn(&client->dev, "Oscillator not enabled. "
					"Set time to enable.\n");

	/* Register sysfs hooks */
	err = device_create_file(&client->dev, &dev_attr_control);
	if (err)
		goto exit_devreg;

	return 0;

exit_devreg:
	rtc_device_unregister(rtc);

exit_detach:
	i2c_detach_client(client);

exit_kfree:
	kfree(client);

exit:
	return err;
}

static int __init ds1672_init(void)
{
	return i2c_add_driver(&ds1672_driver);
}

static void __exit ds1672_exit(void)
{
	i2c_del_driver(&ds1672_driver);
}

MODULE_AUTHOR("Alessandro Zummo <[email protected]>");
MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

module_init(ds1672_init);
module_exit(ds1672_exit);
Commit	Line	Data
edf1aaa3 AZ	1	/*
edf1aaa3 AZ	2	* An rtc/i2c driver for the Dallas DS1672
3903586a AZ	3	* Copyright 2005-06 Tower Technologies
	4	*
	5	* Author: Alessandro Zummo <[email protected]>
edf1aaa3 AZ	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/i2c.h>
	14	#include <linux/rtc.h>
	15
3903586a	16	#define DRV_VERSION "0.3"
edf1aaa3 AZ	17
	18	/* Addresses to scan: none. This chip cannot be detected. */
	19	static unsigned short normal_i2c[] = { I2C_CLIENT_END };
	20
	21	/* Insmod parameters */
	22	I2C_CLIENT_INSMOD;
	23
	24	/* Registers */
	25
	26	#define DS1672_REG_CNT_BASE 0
	27	#define DS1672_REG_CONTROL 4
	28	#define DS1672_REG_TRICKLE 5
	29
3903586a	30	#define DS1672_REG_CONTROL_EOSC 0x80
edf1aaa3 AZ	31
	32	/* Prototypes */
	33	static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind);
	34
	35	/*
	36	* In the routines that deal directly with the ds1672 hardware, we use
	37	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
	38	* Epoch is initialized as 2000. Time is set to UTC.
	39	*/
	40	static int ds1672_get_datetime(struct i2c_client client, struct rtc_time tm)
	41	{
	42	unsigned long time;
	43	unsigned char addr = DS1672_REG_CNT_BASE;
	44	unsigned char buf[4];
	45
	46	struct i2c_msg msgs[] = {
	47	{ client->addr, 0, 1, &addr }, /* setup read ptr */
	48	{ client->addr, I2C_M_RD, 4, buf }, /* read date */
	49	};
	50
	51	/* read date registers */
	52	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
	53	dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
	54	return -EIO;
	55	}
	56
	57	dev_dbg(&client->dev,
11966adc	58	"%s: raw read data - counters=%02x,%02x,%02x,%02x\n",
3903586a	59	__FUNCTION__, buf[0], buf[1], buf[2], buf[3]);
edf1aaa3 AZ	60
	61	time = (buf[3] << 24) \| (buf[2] << 16) \| (buf[1] << 8) \| buf[0];
	62
	63	rtc_time_to_tm(time, tm);
	64
	65	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	66	"mday=%d, mon=%d, year=%d, wday=%d\n",
3903586a	67	__FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour,
edf1aaa3 AZ	68	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	69
	70	return 0;
	71	}
	72
	73	static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs)
	74	{
	75	int xfer;
8a95b252	76	unsigned char buf[6];
edf1aaa3 AZ	77
	78	buf[0] = DS1672_REG_CNT_BASE;
	79	buf[1] = secs & 0x000000FF;
	80	buf[2] = (secs & 0x0000FF00) >> 8;
	81	buf[3] = (secs & 0x00FF0000) >> 16;
	82	buf[4] = (secs & 0xFF000000) >> 24;
8a95b252	83	buf[5] = 0; /* set control reg to enable counting */
edf1aaa3	84
8a95b252 KG	85	xfer = i2c_master_send(client, buf, 6);
8a95b252 KG	86	if (xfer != 6) {
edf1aaa3 AZ	87	dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer);
	88	return -EIO;
	89	}
	90
	91	return 0;
	92	}
	93
	94	static int ds1672_set_datetime(struct i2c_client client, struct rtc_time tm)
	95	{
	96	unsigned long secs;
	97
	98	dev_dbg(&client->dev,
11966adc	99	"%s: secs=%d, mins=%d, hours=%d, "
edf1aaa3 AZ	100	"mday=%d, mon=%d, year=%d, wday=%d\n",
	101	__FUNCTION__,
	102	tm->tm_sec, tm->tm_min, tm->tm_hour,
	103	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	104
	105	rtc_tm_to_time(tm, &secs);
	106
	107	return ds1672_set_mmss(client, secs);
	108	}
	109
	110	static int ds1672_rtc_read_time(struct device dev, struct rtc_time tm)
	111	{
	112	return ds1672_get_datetime(to_i2c_client(dev), tm);
	113	}
	114
	115	static int ds1672_rtc_set_time(struct device dev, struct rtc_time tm)
	116	{
	117	return ds1672_set_datetime(to_i2c_client(dev), tm);
	118	}
	119
	120	static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
	121	{
	122	return ds1672_set_mmss(to_i2c_client(dev), secs);
	123	}
	124
8a95b252 KG	125	static int ds1672_get_control(struct i2c_client client, u8 status)
	126	{
	127	unsigned char addr = DS1672_REG_CONTROL;
	128
	129	struct i2c_msg msgs[] = {
	130	{ client->addr, 0, 1, &addr }, /* setup read ptr */
	131	{ client->addr, I2C_M_RD, 1, status }, /* read control */
	132	};
	133
	134	/* read control register */
	135	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
	136	dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
	137	return -EIO;
	138	}
	139
	140	return 0;
	141	}
	142
	143	/* following are the sysfs callback functions */
	144	static ssize_t show_control(struct device dev, struct device_attribute attr, char *buf)
	145	{
	146	struct i2c_client *client = to_i2c_client(dev);
8a95b252 KG	147	u8 control;
	148	int err;
	149
	150	err = ds1672_get_control(client, &control);
	151	if (err)
	152	return err;
	153
3903586a AZ	154	return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC)
3903586a AZ	155	? "disabled" : "enabled");
8a95b252	156	}
8a95b252 KG	157	static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);
8a95b252 KG	158
ff8371ac	159	static const struct rtc_class_ops ds1672_rtc_ops = {
edf1aaa3 AZ	160	.read_time = ds1672_rtc_read_time,
	161	.set_time = ds1672_rtc_set_time,
	162	.set_mmss = ds1672_rtc_set_mmss,
	163	};
	164
	165	static int ds1672_attach(struct i2c_adapter *adapter)
	166	{
edf1aaa3 AZ	167	return i2c_probe(adapter, &addr_data, ds1672_probe);
	168	}
	169
	170	static int ds1672_detach(struct i2c_client *client)
	171	{
	172	int err;
	173	struct rtc_device *rtc = i2c_get_clientdata(client);
	174
edf1aaa3 AZ	175	if (rtc)
	176	rtc_device_unregister(rtc);
	177
	178	if ((err = i2c_detach_client(client)))
	179	return err;
	180
	181	kfree(client);
	182
	183	return 0;
	184	}
	185
	186	static struct i2c_driver ds1672_driver = {
	187	.driver = {
	188	.name = "ds1672",
	189	},
	190	.id = I2C_DRIVERID_DS1672,
	191	.attach_adapter = &ds1672_attach,
	192	.detach_client = &ds1672_detach,
	193	};
	194
	195	static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind)
	196	{
	197	int err = 0;
8a95b252	198	u8 control;
edf1aaa3 AZ	199	struct i2c_client *client;
	200	struct rtc_device *rtc;
	201
	202	dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
	203
	204	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
	205	err = -ENODEV;
	206	goto exit;
	207	}
	208
	209	if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
	210	err = -ENOMEM;
	211	goto exit;
	212	}
	213
	214	/* I2C client */
	215	client->addr = address;
	216	client->driver = &ds1672_driver;
	217	client->adapter = adapter;
	218
	219	strlcpy(client->name, ds1672_driver.driver.name, I2C_NAME_SIZE);
	220
	221	/* Inform the i2c layer */
	222	if ((err = i2c_attach_client(client)))
	223	goto exit_kfree;
	224
	225	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
	226
	227	rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev,
	228	&ds1672_rtc_ops, THIS_MODULE);
	229
	230	if (IS_ERR(rtc)) {
	231	err = PTR_ERR(rtc);
edf1aaa3 AZ	232	goto exit_detach;
	233	}
	234
	235	i2c_set_clientdata(client, rtc);
	236
8a95b252 KG	237	/* read control register */
8a95b252 KG	238	err = ds1672_get_control(client, &control);
3903586a	239	if (err)
91046a8a	240	goto exit_devreg;
8a95b252 KG	241
	242	if (control & DS1672_REG_CONTROL_EOSC)
	243	dev_warn(&client->dev, "Oscillator not enabled. "
	244	"Set time to enable.\n");
	245
	246	/* Register sysfs hooks */
91046a8a JG	247	err = device_create_file(&client->dev, &dev_attr_control);
	248	if (err)
	249	goto exit_devreg;
8a95b252	250
edf1aaa3 AZ	251	return 0;
edf1aaa3 AZ	252
91046a8a JG	253	exit_devreg:
	254	rtc_device_unregister(rtc);
	255
edf1aaa3 AZ	256	exit_detach:
	257	i2c_detach_client(client);
	258
	259	exit_kfree:
	260	kfree(client);
	261
	262	exit:
	263	return err;
	264	}
	265
	266	static int __init ds1672_init(void)
	267	{
	268	return i2c_add_driver(&ds1672_driver);
	269	}
	270
	271	static void __exit ds1672_exit(void)
	272	{
	273	i2c_del_driver(&ds1672_driver);
	274	}
	275
	276	MODULE_AUTHOR("Alessandro Zummo <[email protected]>");
	277	MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
	278	MODULE_LICENSE("GPL");
	279	MODULE_VERSION(DRV_VERSION);
	280
	281	module_init(ds1672_init);
	282	module_exit(ds1672_exit);