[mirror_ubuntu-bionic-kernel.git] / drivers / rtc / rtc-ds1307.c

/*
 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
 *
 *  Copyright (C) 2005 James Chapman (ds1337 core)
 *  Copyright (C) 2006 David Brownell
 *
 * 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/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/string.h>
#include <linux/rtc.h>
#include <linux/bcd.h>


/* We can't determine type by probing, but if we expect pre-Linux code
 * to have set the chip up as a clock (turning on the oscillator and
 * setting the date and time), Linux can ignore the non-clock features.
 * That's a natural job for a factory or repair bench.
 *
 * This is currently a simple no-alarms driver.  If your board has the
 * alarm irq wired up on a ds1337 or ds1339, and you want to use that,
 * then look at the rtc-rs5c372 driver for code to steal...
 *
 * If the I2C "force" mechanism is used, we assume the chip is a ds1337.
 * (Much better would be board-specific tables of I2C devices, along with
 * the platform_data drivers would use to sort such issues out.)
 */
enum ds_type {
	unknown = 0,
	ds_1307,
	ds_1337,
	ds_1338,
	ds_1339,
	ds_1340,
	m41t00,
	// rs5c372 too?  different address...
};

static unsigned short normal_i2c[] = { 0x68, I2C_CLIENT_END };

I2C_CLIENT_INSMOD;


/* RTC registers don't differ much, except for the century flag */
#define DS1307_REG_SECS		0x00	/* 00-59 */
#	define DS1307_BIT_CH		0x80
#define DS1307_REG_MIN		0x01	/* 00-59 */
#define DS1307_REG_HOUR		0x02	/* 00-23, or 1-12{am,pm} */
#	define DS1340_BIT_CENTURY_EN	0x80	/* in REG_HOUR */
#	define DS1340_BIT_CENTURY	0x40	/* in REG_HOUR */
#define DS1307_REG_WDAY		0x03	/* 01-07 */
#define DS1307_REG_MDAY		0x04	/* 01-31 */
#define DS1307_REG_MONTH	0x05	/* 01-12 */
#	define DS1337_BIT_CENTURY	0x80	/* in REG_MONTH */
#define DS1307_REG_YEAR		0x06	/* 00-99 */

/* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
 * start at 7, and they differ a LOT. Only control and status matter for
 * basic RTC date and time functionality; be careful using them.
 */
#define DS1307_REG_CONTROL	0x07		/* or ds1338 */
#	define DS1307_BIT_OUT		0x80
#	define DS1338_BIT_STOP		0x20
#	define DS1307_BIT_SQWE		0x10
#	define DS1307_BIT_RS1		0x02
#	define DS1307_BIT_RS0		0x01
#define DS1337_REG_CONTROL	0x0e
#	define DS1337_BIT_nEOSC		0x80
#	define DS1337_BIT_RS2		0x10
#	define DS1337_BIT_RS1		0x08
#	define DS1337_BIT_INTCN		0x04
#	define DS1337_BIT_A2IE		0x02
#	define DS1337_BIT_A1IE		0x01
#define DS1340_REG_CONTROL	0x07
#	define DS1340_BIT_OUT		0x80
#	define DS1340_BIT_FT		0x40
#	define DS1340_BIT_CALIB_SIGN	0x20
#	define DS1340_M_CALIBRATION	0x1f
#define DS1338_REG_FLAG		0x09
#	define DS1338_BIT_OSF		0x80
#define DS1337_REG_STATUS	0x0f
#	define DS1337_BIT_OSF		0x80
#	define DS1337_BIT_A2I		0x02
#	define DS1337_BIT_A1I		0x01
#define DS1339_REG_TRICKLE	0x10


struct ds1307 {
	u8			reg_addr;
	u8			regs[8];
	enum ds_type		type;
	struct i2c_msg		msg[2];
	struct i2c_client	*client;
	struct i2c_client	dev;
	struct rtc_device	*rtc;
};

struct chip_desc {
	char			name[9];
	unsigned		nvram56:1;
	unsigned		alarm:1;
	enum ds_type		type;
};

static const struct chip_desc chips[] = { {
	.name		= "ds1307",
	.type		= ds_1307,
	.nvram56	= 1,
}, {
	.name		= "ds1337",
	.type		= ds_1337,
	.alarm		= 1,
}, {
	.name		= "ds1338",
	.type		= ds_1338,
	.nvram56	= 1,
}, {
	.name		= "ds1339",
	.type		= ds_1339,
	.alarm		= 1,
}, {
	.name		= "ds1340",
	.type		= ds_1340,
}, {
	.name		= "m41t00",
	.type		= m41t00,
}, };

static inline const struct chip_desc *find_chip(const char *s)
{
	unsigned i;

	for (i = 0; i < ARRAY_SIZE(chips); i++)
		if (strnicmp(s, chips[i].name, sizeof chips[i].name) == 0)
			return &chips[i];
	return NULL;
}

static int ds1307_get_time(struct device *dev, struct rtc_time *t)
{
	struct ds1307	*ds1307 = dev_get_drvdata(dev);
	int		tmp;

	/* read the RTC date and time registers all at once */
	ds1307->msg[1].flags = I2C_M_RD;
	ds1307->msg[1].len = 7;

	tmp = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
			ds1307->msg, 2);
	if (tmp != 2) {
		dev_err(dev, "%s error %d\n", "read", tmp);
		return -EIO;
	}

	dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
			"read",
			ds1307->regs[0], ds1307->regs[1],
			ds1307->regs[2], ds1307->regs[3],
			ds1307->regs[4], ds1307->regs[5],
			ds1307->regs[6]);

	t->tm_sec = BCD2BIN(ds1307->regs[DS1307_REG_SECS] & 0x7f);
	t->tm_min = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
	tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
	t->tm_hour = BCD2BIN(tmp);
	t->tm_wday = BCD2BIN(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
	t->tm_mday = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
	tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
	t->tm_mon = BCD2BIN(tmp) - 1;

	/* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
	t->tm_year = BCD2BIN(ds1307->regs[DS1307_REG_YEAR]) + 100;

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

	/* initial clock setting can be undefined */
	return rtc_valid_tm(t);
}

static int ds1307_set_time(struct device *dev, struct rtc_time *t)
{
	struct ds1307	*ds1307 = dev_get_drvdata(dev);
	int		result;
	int		tmp;
	u8		*buf = ds1307->regs;

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

	*buf++ = 0;		/* first register addr */
	buf[DS1307_REG_SECS] = BIN2BCD(t->tm_sec);
	buf[DS1307_REG_MIN] = BIN2BCD(t->tm_min);
	buf[DS1307_REG_HOUR] = BIN2BCD(t->tm_hour);
	buf[DS1307_REG_WDAY] = BIN2BCD(t->tm_wday + 1);
	buf[DS1307_REG_MDAY] = BIN2BCD(t->tm_mday);
	buf[DS1307_REG_MONTH] = BIN2BCD(t->tm_mon + 1);

	/* assume 20YY not 19YY */
	tmp = t->tm_year - 100;
	buf[DS1307_REG_YEAR] = BIN2BCD(tmp);

	if (ds1307->type == ds_1337)
		buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
	else if (ds1307->type == ds_1340)
		buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
				| DS1340_BIT_CENTURY;

	ds1307->msg[1].flags = 0;
	ds1307->msg[1].len = 8;

	dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
		"write", buf[0], buf[1], buf[2], buf[3],
		buf[4], buf[5], buf[6]);

	result = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
			&ds1307->msg[1], 1);
	if (result != 1) {
		dev_err(dev, "%s error %d\n", "write", tmp);
		return -EIO;
	}
	return 0;
}

static const struct rtc_class_ops ds13xx_rtc_ops = {
	.read_time	= ds1307_get_time,
	.set_time	= ds1307_set_time,
};

static struct i2c_driver ds1307_driver;

static int __devinit
ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
{
	struct ds1307		*ds1307;
	int			err = -ENODEV;
	struct i2c_client	*client;
	int			tmp;
	const struct chip_desc	*chip;

	if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) {
		err = -ENOMEM;
		goto exit;
	}

	/* REVISIT:  pending driver model conversion, set up "client"
	 * ourselves, and use a hack to determine the RTC type (instead
	 * of reading the client->name we're given)
	 */
	client = &ds1307->dev;
	client->addr = address;
	client->adapter = adapter;
	client->driver = &ds1307_driver;

	/* HACK: "force" implies "needs ds1337-style-oscillator setup", and
	 * that's the only kind of chip setup we'll know about.  Until the
	 * driver model conversion, here's where to add any board-specific
	 * code to say what kind of chip is present...
	 */
	if (kind >= 0)
		chip = find_chip("ds1337");
	else
		chip = find_chip("ds1307");
	strlcpy(client->name, chip->name, I2C_NAME_SIZE);

	ds1307->client = client;
	i2c_set_clientdata(client, ds1307);

	ds1307->msg[0].addr = client->addr;
	ds1307->msg[0].flags = 0;
	ds1307->msg[0].len = 1;
	ds1307->msg[0].buf = &ds1307->reg_addr;

	ds1307->msg[1].addr = client->addr;
	ds1307->msg[1].flags = I2C_M_RD;
	ds1307->msg[1].len = sizeof(ds1307->regs);
	ds1307->msg[1].buf = ds1307->regs;

	ds1307->type = chip->type;

	switch (ds1307->type) {
	case ds_1337:
	case ds_1339:
		ds1307->type = ds_1337;

		ds1307->reg_addr = DS1337_REG_CONTROL;
		ds1307->msg[1].len = 2;

		tmp = i2c_transfer(adapter, ds1307->msg, 2);
		if (tmp != 2) {
			pr_debug("read error %d\n", tmp);
			err = -EIO;
			goto exit_free;
		}

		ds1307->reg_addr = 0;
		ds1307->msg[1].len = sizeof(ds1307->regs);

		/* oscillator is off; need to turn it on */
		if ((ds1307->regs[0] & DS1337_BIT_nEOSC)
				|| (ds1307->regs[1] & DS1337_BIT_OSF)) {
no_osc_start:
			printk(KERN_ERR "no %s oscillator code\n",
				chip->name);
			goto exit_free;
		}
		break;
	default:
		break;
	}

read_rtc:
	/* read RTC registers */

	tmp = i2c_transfer(adapter, ds1307->msg, 2);
	if (tmp != 2) {
		pr_debug("read error %d\n", tmp);
		err = -EIO;
		goto exit_free;
	}

	/* minimal sanity checking; some chips (like DS1340) don't
	 * specify the extra bits as must-be-zero, but there are
	 * still a few values that are clearly out-of-range.
	 */
	tmp = ds1307->regs[DS1307_REG_SECS];
	switch (ds1307->type) {
	case ds_1307:
	case ds_1338:
	case m41t00:
		if (tmp & DS1307_BIT_CH) {
			i2c_smbus_write_byte_data(client, 0, 0);
			dev_warn(&client->dev,
				"oscillator started; SET TIME!\n");
			goto read_rtc;
		}
		break;
	case ds_1340:
		/* FIXME write code to start the oscillator */
		if (tmp & DS1307_BIT_CH)
			goto no_osc_start;
		break;
	default:
		break;
	}

	tmp = ds1307->regs[DS1307_REG_SECS];
	tmp = BCD2BIN(tmp & 0x7f);
	if (tmp > 60)
		goto exit_free;
	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
	if (tmp > 60)
		goto exit_free;

	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
	if (tmp == 0 || tmp > 31)
		goto exit_free;

	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f);
	if (tmp == 0 || tmp > 12)
		goto exit_free;

	/* force into in 24 hour mode (most chips) or
	 * disable century bit (ds1340)
	 *
	 * REVISIT forcing 24 hour mode can prevent multi-master
	 * configs from sharing this RTC ... don't do this.
	 */
	tmp = ds1307->regs[DS1307_REG_HOUR];
	if (tmp & (1 << 6)) {
		if (tmp & (1 << 5))
			tmp = BCD2BIN(tmp & 0x1f) + 12;
		else
			tmp = BCD2BIN(tmp);
		i2c_smbus_write_byte_data(client,
				DS1307_REG_HOUR,
				BIN2BCD(tmp));
	}

	/* Tell the I2C layer a new client has arrived */
	if ((err = i2c_attach_client(client)))
		goto exit_free;

	ds1307->rtc = rtc_device_register(client->name, &client->dev,
				&ds13xx_rtc_ops, THIS_MODULE);
	if (IS_ERR(ds1307->rtc)) {
		err = PTR_ERR(ds1307->rtc);
		dev_err(&client->dev,
			"unable to register the class device\n");
		goto exit_detach;
	}

	return 0;

exit_detach:
	i2c_detach_client(client);
exit_free:
	kfree(ds1307);
exit:
	return err;
}

static int __devinit
ds1307_attach_adapter(struct i2c_adapter *adapter)
{
	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
		return 0;
	return i2c_probe(adapter, &addr_data, ds1307_detect);
}

static int __devexit ds1307_detach_client(struct i2c_client *client)
{
	int		err;
	struct ds1307	*ds1307 = i2c_get_clientdata(client);

	rtc_device_unregister(ds1307->rtc);
	if ((err = i2c_detach_client(client)))
		return err;
	kfree(ds1307);
	return 0;
}

static struct i2c_driver ds1307_driver = {
	.driver = {
		.name	= "ds1307",
		.owner	= THIS_MODULE,
	},
	.attach_adapter	= ds1307_attach_adapter,
	.detach_client	= __devexit_p(ds1307_detach_client),
};

static int __init ds1307_init(void)
{
	return i2c_add_driver(&ds1307_driver);
}
module_init(ds1307_init);

static void __exit ds1307_exit(void)
{
	i2c_del_driver(&ds1307_driver);
}
module_exit(ds1307_exit);

MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
MODULE_LICENSE("GPL");
Commit	Line	Data
1abb0dc9 DB	1	/*
	2	* rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
	3	*
	4	* Copyright (C) 2005 James Chapman (ds1337 core)
	5	* Copyright (C) 2006 David Brownell
	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/init.h>
	14	#include <linux/slab.h>
	15	#include <linux/i2c.h>
	16	#include <linux/string.h>
	17	#include <linux/rtc.h>
	18	#include <linux/bcd.h>
	19
	20
	21
	22	/* We can't determine type by probing, but if we expect pre-Linux code
	23	* to have set the chip up as a clock (turning on the oscillator and
	24	* setting the date and time), Linux can ignore the non-clock features.
	25	* That's a natural job for a factory or repair bench.
	26	*
045e0e85 DB	27	* This is currently a simple no-alarms driver. If your board has the
	28	* alarm irq wired up on a ds1337 or ds1339, and you want to use that,
	29	* then look at the rtc-rs5c372 driver for code to steal...
	30	*
1abb0dc9 DB	31	* If the I2C "force" mechanism is used, we assume the chip is a ds1337.
	32	* (Much better would be board-specific tables of I2C devices, along with
	33	* the platform_data drivers would use to sort such issues out.)
	34	*/
	35	enum ds_type {
	36	unknown = 0,
045e0e85 DB	37	ds_1307,
	38	ds_1337,
	39	ds_1338,
	40	ds_1339,
	41	ds_1340,
	42	m41t00,
1abb0dc9 DB	43	// rs5c372 too? different address...
	44	};
	45
	46	static unsigned short normal_i2c[] = { 0x68, I2C_CLIENT_END };
	47
	48	I2C_CLIENT_INSMOD;
	49
	50
	51
	52	/* RTC registers don't differ much, except for the century flag */
	53	#define DS1307_REG_SECS 0x00 /* 00-59 */
	54	# define DS1307_BIT_CH 0x80
	55	#define DS1307_REG_MIN 0x01 /* 00-59 */
	56	#define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
	57	# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
	58	# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
	59	#define DS1307_REG_WDAY 0x03 /* 01-07 */
	60	#define DS1307_REG_MDAY 0x04 /* 01-31 */
	61	#define DS1307_REG_MONTH 0x05 /* 01-12 */
	62	# define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
	63	#define DS1307_REG_YEAR 0x06 /* 00-99 */
	64
	65	/* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
045e0e85 DB	66	* start at 7, and they differ a LOT. Only control and status matter for
045e0e85 DB	67	* basic RTC date and time functionality; be careful using them.
1abb0dc9	68	*/
045e0e85	69	#define DS1307_REG_CONTROL 0x07 /* or ds1338 */
1abb0dc9	70	# define DS1307_BIT_OUT 0x80
045e0e85	71	# define DS1338_BIT_STOP 0x20
1abb0dc9 DB	72	# define DS1307_BIT_SQWE 0x10
	73	# define DS1307_BIT_RS1 0x02
	74	# define DS1307_BIT_RS0 0x01
	75	#define DS1337_REG_CONTROL 0x0e
	76	# define DS1337_BIT_nEOSC 0x80
	77	# define DS1337_BIT_RS2 0x10
	78	# define DS1337_BIT_RS1 0x08
	79	# define DS1337_BIT_INTCN 0x04
	80	# define DS1337_BIT_A2IE 0x02
	81	# define DS1337_BIT_A1IE 0x01
045e0e85 DB	82	#define DS1340_REG_CONTROL 0x07
	83	# define DS1340_BIT_OUT 0x80
	84	# define DS1340_BIT_FT 0x40
	85	# define DS1340_BIT_CALIB_SIGN 0x20
	86	# define DS1340_M_CALIBRATION 0x1f
	87	#define DS1338_REG_FLAG 0x09
	88	# define DS1338_BIT_OSF 0x80
1abb0dc9 DB	89	#define DS1337_REG_STATUS 0x0f
	90	# define DS1337_BIT_OSF 0x80
	91	# define DS1337_BIT_A2I 0x02
	92	# define DS1337_BIT_A1I 0x01
	93	#define DS1339_REG_TRICKLE 0x10
	94
	95
	96
	97	struct ds1307 {
	98	u8 reg_addr;
	99	u8 regs[8];
	100	enum ds_type type;
	101	struct i2c_msg msg[2];
045e0e85 DB	102	struct i2c_client *client;
045e0e85 DB	103	struct i2c_client dev;
1abb0dc9 DB	104	struct rtc_device *rtc;
	105	};
	106
045e0e85 DB	107	struct chip_desc {
	108	char name[9];
	109	unsigned nvram56:1;
	110	unsigned alarm:1;
	111	enum ds_type type;
	112	};
	113
	114	static const struct chip_desc chips[] = { {
	115	.name = "ds1307",
	116	.type = ds_1307,
	117	.nvram56 = 1,
	118	}, {
	119	.name = "ds1337",
	120	.type = ds_1337,
	121	.alarm = 1,
	122	}, {
	123	.name = "ds1338",
	124	.type = ds_1338,
	125	.nvram56 = 1,
	126	}, {
	127	.name = "ds1339",
	128	.type = ds_1339,
	129	.alarm = 1,
	130	}, {
	131	.name = "ds1340",
	132	.type = ds_1340,
	133	}, {
	134	.name = "m41t00",
	135	.type = m41t00,
	136	}, };
	137
	138	static inline const struct chip_desc find_chip(const char s)
	139	{
	140	unsigned i;
	141
	142	for (i = 0; i < ARRAY_SIZE(chips); i++)
	143	if (strnicmp(s, chips[i].name, sizeof chips[i].name) == 0)
	144	return &chips[i];
	145	return NULL;
	146	}
1abb0dc9 DB	147
	148	static int ds1307_get_time(struct device dev, struct rtc_time t)
	149	{
	150	struct ds1307 *ds1307 = dev_get_drvdata(dev);
	151	int tmp;
	152
045e0e85	153	/* read the RTC date and time registers all at once */
1abb0dc9 DB	154	ds1307->msg[1].flags = I2C_M_RD;
	155	ds1307->msg[1].len = 7;
	156
045e0e85 DB	157	tmp = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
045e0e85 DB	158	ds1307->msg, 2);
1abb0dc9 DB	159	if (tmp != 2) {
	160	dev_err(dev, "%s error %d\n", "read", tmp);
	161	return -EIO;
	162	}
	163
	164	dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
	165	"read",
	166	ds1307->regs[0], ds1307->regs[1],
	167	ds1307->regs[2], ds1307->regs[3],
	168	ds1307->regs[4], ds1307->regs[5],
	169	ds1307->regs[6]);
	170
	171	t->tm_sec = BCD2BIN(ds1307->regs[DS1307_REG_SECS] & 0x7f);
	172	t->tm_min = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
	173	tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
	174	t->tm_hour = BCD2BIN(tmp);
	175	t->tm_wday = BCD2BIN(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
	176	t->tm_mday = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
	177	tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
	178	t->tm_mon = BCD2BIN(tmp) - 1;
	179
	180	/* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
	181	t->tm_year = BCD2BIN(ds1307->regs[DS1307_REG_YEAR]) + 100;
	182
	183	dev_dbg(dev, "%s secs=%d, mins=%d, "
	184	"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
	185	"read", t->tm_sec, t->tm_min,
	186	t->tm_hour, t->tm_mday,
	187	t->tm_mon, t->tm_year, t->tm_wday);
	188
045e0e85 DB	189	/* initial clock setting can be undefined */
045e0e85 DB	190	return rtc_valid_tm(t);
1abb0dc9 DB	191	}
	192
	193	static int ds1307_set_time(struct device dev, struct rtc_time t)
	194	{
	195	struct ds1307 *ds1307 = dev_get_drvdata(dev);
	196	int result;
	197	int tmp;
	198	u8 *buf = ds1307->regs;
	199
	200	dev_dbg(dev, "%s secs=%d, mins=%d, "
	201	"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
11966adc JG	202	"write", t->tm_sec, t->tm_min,
	203	t->tm_hour, t->tm_mday,
	204	t->tm_mon, t->tm_year, t->tm_wday);
1abb0dc9 DB	205
	206	buf++ = 0; / first register addr */
	207	buf[DS1307_REG_SECS] = BIN2BCD(t->tm_sec);
	208	buf[DS1307_REG_MIN] = BIN2BCD(t->tm_min);
	209	buf[DS1307_REG_HOUR] = BIN2BCD(t->tm_hour);
	210	buf[DS1307_REG_WDAY] = BIN2BCD(t->tm_wday + 1);
	211	buf[DS1307_REG_MDAY] = BIN2BCD(t->tm_mday);
	212	buf[DS1307_REG_MONTH] = BIN2BCD(t->tm_mon + 1);
	213
	214	/* assume 20YY not 19YY */
	215	tmp = t->tm_year - 100;
	216	buf[DS1307_REG_YEAR] = BIN2BCD(tmp);
	217
	218	if (ds1307->type == ds_1337)
	219	buf[DS1307_REG_MONTH] \|= DS1337_BIT_CENTURY;
	220	else if (ds1307->type == ds_1340)
	221	buf[DS1307_REG_HOUR] \|= DS1340_BIT_CENTURY_EN
	222	\| DS1340_BIT_CENTURY;
	223
	224	ds1307->msg[1].flags = 0;
	225	ds1307->msg[1].len = 8;
	226
	227	dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
	228	"write", buf[0], buf[1], buf[2], buf[3],
	229	buf[4], buf[5], buf[6]);
	230
045e0e85 DB	231	result = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
045e0e85 DB	232	&ds1307->msg[1], 1);
1abb0dc9 DB	233	if (result != 1) {
	234	dev_err(dev, "%s error %d\n", "write", tmp);
	235	return -EIO;
	236	}
	237	return 0;
	238	}
	239
ff8371ac	240	static const struct rtc_class_ops ds13xx_rtc_ops = {
1abb0dc9 DB	241	.read_time = ds1307_get_time,
	242	.set_time = ds1307_set_time,
	243	};
	244
	245	static struct i2c_driver ds1307_driver;
	246
	247	static int __devinit
	248	ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
	249	{
	250	struct ds1307 *ds1307;
	251	int err = -ENODEV;
	252	struct i2c_client *client;
	253	int tmp;
045e0e85	254	const struct chip_desc *chip;
1abb0dc9 DB	255
	256	if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) {
	257	err = -ENOMEM;
	258	goto exit;
	259	}
	260
045e0e85 DB	261	/* REVISIT: pending driver model conversion, set up "client"
	262	* ourselves, and use a hack to determine the RTC type (instead
	263	* of reading the client->name we're given)
	264	*/
	265	client = &ds1307->dev;
1abb0dc9 DB	266	client->addr = address;
	267	client->adapter = adapter;
	268	client->driver = &ds1307_driver;
1abb0dc9	269
045e0e85 DB	270	/* HACK: "force" implies "needs ds1337-style-oscillator setup", and
	271	* that's the only kind of chip setup we'll know about. Until the
	272	* driver model conversion, here's where to add any board-specific
	273	* code to say what kind of chip is present...
	274	*/
	275	if (kind >= 0)
	276	chip = find_chip("ds1337");
	277	else
	278	chip = find_chip("ds1307");
	279	strlcpy(client->name, chip->name, I2C_NAME_SIZE);
	280
	281	ds1307->client = client;
1abb0dc9 DB	282	i2c_set_clientdata(client, ds1307);
	283
	284	ds1307->msg[0].addr = client->addr;
	285	ds1307->msg[0].flags = 0;
	286	ds1307->msg[0].len = 1;
	287	ds1307->msg[0].buf = &ds1307->reg_addr;
	288
	289	ds1307->msg[1].addr = client->addr;
	290	ds1307->msg[1].flags = I2C_M_RD;
	291	ds1307->msg[1].len = sizeof(ds1307->regs);
	292	ds1307->msg[1].buf = ds1307->regs;
	293
045e0e85 DB	294	ds1307->type = chip->type;
	295
	296	switch (ds1307->type) {
	297	case ds_1337:
	298	case ds_1339:
1abb0dc9 DB	299	ds1307->type = ds_1337;
	300
	301	ds1307->reg_addr = DS1337_REG_CONTROL;
	302	ds1307->msg[1].len = 2;
	303
045e0e85	304	tmp = i2c_transfer(adapter, ds1307->msg, 2);
1abb0dc9 DB	305	if (tmp != 2) {
	306	pr_debug("read error %d\n", tmp);
	307	err = -EIO;
	308	goto exit_free;
	309	}
	310
	311	ds1307->reg_addr = 0;
	312	ds1307->msg[1].len = sizeof(ds1307->regs);
	313
	314	/* oscillator is off; need to turn it on */
	315	if ((ds1307->regs[0] & DS1337_BIT_nEOSC)
	316	\|\| (ds1307->regs[1] & DS1337_BIT_OSF)) {
045e0e85 DB	317	no_osc_start:
	318	printk(KERN_ERR "no %s oscillator code\n",
	319	chip->name);
1abb0dc9 DB	320	goto exit_free;
1abb0dc9 DB	321	}
045e0e85 DB	322	break;
	323	default:
	324	break;
	325	}
1abb0dc9 DB	326
	327	read_rtc:
	328	/* read RTC registers */
	329
045e0e85	330	tmp = i2c_transfer(adapter, ds1307->msg, 2);
1abb0dc9 DB	331	if (tmp != 2) {
	332	pr_debug("read error %d\n", tmp);
	333	err = -EIO;
	334	goto exit_free;
	335	}
	336
	337	/* minimal sanity checking; some chips (like DS1340) don't
	338	* specify the extra bits as must-be-zero, but there are
	339	* still a few values that are clearly out-of-range.
	340	*/
	341	tmp = ds1307->regs[DS1307_REG_SECS];
045e0e85 DB	342	switch (ds1307->type) {
	343	case ds_1307:
	344	case ds_1338:
	345	case m41t00:
	346	if (tmp & DS1307_BIT_CH) {
	347	i2c_smbus_write_byte_data(client, 0, 0);
	348	dev_warn(&client->dev,
	349	"oscillator started; SET TIME!\n");
	350	goto read_rtc;
1abb0dc9	351	}
045e0e85 DB	352	break;
	353	case ds_1340:
	354	/* FIXME write code to start the oscillator */
	355	if (tmp & DS1307_BIT_CH)
	356	goto no_osc_start;
	357	break;
	358	default:
	359	break;
1abb0dc9	360	}
045e0e85 DB	361
045e0e85 DB	362	tmp = ds1307->regs[DS1307_REG_SECS];
1abb0dc9 DB	363	tmp = BCD2BIN(tmp & 0x7f);
	364	if (tmp > 60)
	365	goto exit_free;
	366	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
	367	if (tmp > 60)
	368	goto exit_free;
	369
	370	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
	371	if (tmp == 0 \|\| tmp > 31)
	372	goto exit_free;
	373
	374	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f);
	375	if (tmp == 0 \|\| tmp > 12)
	376	goto exit_free;
	377
	378	/* force into in 24 hour mode (most chips) or
	379	* disable century bit (ds1340)
045e0e85 DB	380	*
	381	* REVISIT forcing 24 hour mode can prevent multi-master
	382	* configs from sharing this RTC ... don't do this.
1abb0dc9 DB	383	*/
	384	tmp = ds1307->regs[DS1307_REG_HOUR];
	385	if (tmp & (1 << 6)) {
	386	if (tmp & (1 << 5))
	387	tmp = BCD2BIN(tmp & 0x1f) + 12;
	388	else
	389	tmp = BCD2BIN(tmp);
	390	i2c_smbus_write_byte_data(client,
	391	DS1307_REG_HOUR,
	392	BIN2BCD(tmp));
	393	}
	394
1abb0dc9 DB	395	/* Tell the I2C layer a new client has arrived */
	396	if ((err = i2c_attach_client(client)))
	397	goto exit_free;
	398
	399	ds1307->rtc = rtc_device_register(client->name, &client->dev,
	400	&ds13xx_rtc_ops, THIS_MODULE);
	401	if (IS_ERR(ds1307->rtc)) {
	402	err = PTR_ERR(ds1307->rtc);
	403	dev_err(&client->dev,
	404	"unable to register the class device\n");
	405	goto exit_detach;
	406	}
	407
	408	return 0;
	409
	410	exit_detach:
	411	i2c_detach_client(client);
	412	exit_free:
	413	kfree(ds1307);
	414	exit:
	415	return err;
	416	}
	417
	418	static int __devinit
	419	ds1307_attach_adapter(struct i2c_adapter *adapter)
	420	{
	421	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
	422	return 0;
	423	return i2c_probe(adapter, &addr_data, ds1307_detect);
	424	}
	425
	426	static int __devexit ds1307_detach_client(struct i2c_client *client)
	427	{
	428	int err;
	429	struct ds1307 *ds1307 = i2c_get_clientdata(client);
	430
	431	rtc_device_unregister(ds1307->rtc);
	432	if ((err = i2c_detach_client(client)))
	433	return err;
	434	kfree(ds1307);
	435	return 0;
	436	}
	437
	438	static struct i2c_driver ds1307_driver = {
	439	.driver = {
	440	.name = "ds1307",
	441	.owner = THIS_MODULE,
	442	},
	443	.attach_adapter = ds1307_attach_adapter,
	444	.detach_client = __devexit_p(ds1307_detach_client),
	445	};
	446
	447	static int __init ds1307_init(void)
	448	{
	449	return i2c_add_driver(&ds1307_driver);
	450	}
	451	module_init(ds1307_init);
	452
	453	static void __exit ds1307_exit(void)
	454	{
	455	i2c_del_driver(&ds1307_driver);
	456	}
	457	module_exit(ds1307_exit);
	458
459	MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
460	MODULE_LICENSE("GPL");