rtc-ds1307.c 25.0 KB
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/*
 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
 *
 *  Copyright (C) 2005 James Chapman (ds1337 core)
 *  Copyright (C) 2006 David Brownell
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 *  Copyright (C) 2009 Matthias Fuchs (rx8025 support)
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 *
 * 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>



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/*
 * We can't determine type by probing, but if we expect pre-Linux code
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 * 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.
 */
enum ds_type {
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	ds_1307,
	ds_1337,
	ds_1338,
	ds_1339,
	ds_1340,
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	ds_1388,
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	ds_3231,
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	m41t00,
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	mcp7941x,
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	rx_8025,
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	last_ds_type /* always last */
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	/* rs5c372 too?  different address... */
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};


/* RTC registers don't differ much, except for the century flag */
#define DS1307_REG_SECS		0x00	/* 00-59 */
#	define DS1307_BIT_CH		0x80
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#	define DS1340_BIT_nEOSC		0x80
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#	define MCP7941X_BIT_ST		0x80
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#define DS1307_REG_MIN		0x01	/* 00-59 */
#define DS1307_REG_HOUR		0x02	/* 00-23, or 1-12{am,pm} */
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#	define DS1307_BIT_12HR		0x40	/* in REG_HOUR */
#	define DS1307_BIT_PM		0x20	/* in REG_HOUR */
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#	define DS1340_BIT_CENTURY_EN	0x80	/* in REG_HOUR */
#	define DS1340_BIT_CENTURY	0x40	/* in REG_HOUR */
#define DS1307_REG_WDAY		0x03	/* 01-07 */
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#	define MCP7941X_BIT_VBATEN	0x08
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#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 */

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/*
 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
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 * start at 7, and they differ a LOT. Only control and status matter for
 * basic RTC date and time functionality; be careful using them.
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 */
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#define DS1307_REG_CONTROL	0x07		/* or ds1338 */
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#	define DS1307_BIT_OUT		0x80
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#	define DS1338_BIT_OSF		0x20
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#	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
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#	define DS1339_BIT_BBSQI		0x20
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#	define DS3231_BIT_BBSQW		0x40 /* same as BBSQI */
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#	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
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#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
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#define DS1340_REG_FLAG		0x09
#	define DS1340_BIT_OSF		0x80
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#define DS1337_REG_STATUS	0x0f
#	define DS1337_BIT_OSF		0x80
#	define DS1337_BIT_A2I		0x02
#	define DS1337_BIT_A1I		0x01
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#define DS1339_REG_ALARM1_SECS	0x07
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#define DS1339_REG_TRICKLE	0x10

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#define RX8025_REG_CTRL1	0x0e
#	define RX8025_BIT_2412		0x20
#define RX8025_REG_CTRL2	0x0f
#	define RX8025_BIT_PON		0x10
#	define RX8025_BIT_VDET		0x40
#	define RX8025_BIT_XST		0x20
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struct ds1307 {
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	u8			offset; /* register's offset */
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	u8			regs[11];
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	u16			nvram_offset;
	struct bin_attribute	*nvram;
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	enum ds_type		type;
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	unsigned long		flags;
#define HAS_NVRAM	0		/* bit 0 == sysfs file active */
#define HAS_ALARM	1		/* bit 1 == irq claimed */
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	struct i2c_client	*client;
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	struct rtc_device	*rtc;
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	struct work_struct	work;
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	s32 (*read_block_data)(const struct i2c_client *client, u8 command,
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			       u8 length, u8 *values);
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	s32 (*write_block_data)(const struct i2c_client *client, u8 command,
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				u8 length, const u8 *values);
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};

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struct chip_desc {
	unsigned		alarm:1;
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	u16			nvram_offset;
	u16			nvram_size;
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};

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static const struct chip_desc chips[last_ds_type] = {
	[ds_1307] = {
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		.nvram_offset	= 8,
		.nvram_size	= 56,
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	},
	[ds_1337] = {
		.alarm		= 1,
	},
	[ds_1338] = {
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		.nvram_offset	= 8,
		.nvram_size	= 56,
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	},
	[ds_1339] = {
		.alarm		= 1,
	},
	[ds_3231] = {
		.alarm		= 1,
	},
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	[mcp7941x] = {
		/* this is battery backed SRAM */
		.nvram_offset	= 0x20,
		.nvram_size	= 0x40,
	},
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};
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static const struct i2c_device_id ds1307_id[] = {
	{ "ds1307", ds_1307 },
	{ "ds1337", ds_1337 },
	{ "ds1338", ds_1338 },
	{ "ds1339", ds_1339 },
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	{ "ds1388", ds_1388 },
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	{ "ds1340", ds_1340 },
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	{ "ds3231", ds_3231 },
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	{ "m41t00", m41t00 },
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	{ "mcp7941x", mcp7941x },
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	{ "pt7c4338", ds_1307 },
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	{ "rx8025", rx_8025 },
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	{ }
};
MODULE_DEVICE_TABLE(i2c, ds1307_id);
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/*----------------------------------------------------------------------*/

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#define BLOCK_DATA_MAX_TRIES 10

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static s32 ds1307_read_block_data_once(const struct i2c_client *client,
				       u8 command, u8 length, u8 *values)
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{
	s32 i, data;

	for (i = 0; i < length; i++) {
		data = i2c_smbus_read_byte_data(client, command + i);
		if (data < 0)
			return data;
		values[i] = data;
	}
	return i;
}

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static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
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				  u8 length, u8 *values)
{
	u8 oldvalues[I2C_SMBUS_BLOCK_MAX];
	s32 ret;
	int tries = 0;

	dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
	ret = ds1307_read_block_data_once(client, command, length, values);
	if (ret < 0)
		return ret;
	do {
		if (++tries > BLOCK_DATA_MAX_TRIES) {
			dev_err(&client->dev,
				"ds1307_read_block_data failed\n");
			return -EIO;
		}
		memcpy(oldvalues, values, length);
		ret = ds1307_read_block_data_once(client, command, length,
						  values);
		if (ret < 0)
			return ret;
	} while (memcmp(oldvalues, values, length));
	return length;
}

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static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
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				   u8 length, const u8 *values)
{
	u8 currvalues[I2C_SMBUS_BLOCK_MAX];
	int tries = 0;

	dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
	do {
		s32 i, ret;

		if (++tries > BLOCK_DATA_MAX_TRIES) {
			dev_err(&client->dev,
				"ds1307_write_block_data failed\n");
			return -EIO;
		}
		for (i = 0; i < length; i++) {
			ret = i2c_smbus_write_byte_data(client, command + i,
							values[i]);
			if (ret < 0)
				return ret;
		}
		ret = ds1307_read_block_data_once(client, command, length,
						  currvalues);
		if (ret < 0)
			return ret;
	} while (memcmp(currvalues, values, length));
	return length;
}

/*----------------------------------------------------------------------*/

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/*
 * The IRQ logic includes a "real" handler running in IRQ context just
 * long enough to schedule this workqueue entry.   We need a task context
 * to talk to the RTC, since I2C I/O calls require that; and disable the
 * IRQ until we clear its status on the chip, so that this handler can
 * work with any type of triggering (not just falling edge).
 *
 * The ds1337 and ds1339 both have two alarms, but we only use the first
 * one (with a "seconds" field).  For ds1337 we expect nINTA is our alarm
 * signal; ds1339 chips have only one alarm signal.
 */
static void ds1307_work(struct work_struct *work)
{
	struct ds1307		*ds1307;
	struct i2c_client	*client;
	struct mutex		*lock;
	int			stat, control;

	ds1307 = container_of(work, struct ds1307, work);
	client = ds1307->client;
	lock = &ds1307->rtc->ops_lock;

	mutex_lock(lock);
	stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
	if (stat < 0)
		goto out;

	if (stat & DS1337_BIT_A1I) {
		stat &= ~DS1337_BIT_A1I;
		i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);

		control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
		if (control < 0)
			goto out;

		control &= ~DS1337_BIT_A1IE;
		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);

		rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
	}

out:
	if (test_bit(HAS_ALARM, &ds1307->flags))
		enable_irq(client->irq);
	mutex_unlock(lock);
}

static irqreturn_t ds1307_irq(int irq, void *dev_id)
{
	struct i2c_client	*client = dev_id;
	struct ds1307		*ds1307 = i2c_get_clientdata(client);

	disable_irq_nosync(irq);
	schedule_work(&ds1307->work);
	return IRQ_HANDLED;
}

/*----------------------------------------------------------------------*/

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

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	/* read the RTC date and time registers all at once */
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	tmp = ds1307->read_block_data(ds1307->client,
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		ds1307->offset, 7, ds1307->regs);
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	if (tmp != 7) {
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		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]);

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	t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
	t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
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	tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
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	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);
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	tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
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	t->tm_mon = bcd2bin(tmp) - 1;
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	/* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
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	t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
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	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);

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

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",
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		"write", t->tm_sec, t->tm_min,
		t->tm_hour, t->tm_mday,
		t->tm_mon, t->tm_year, t->tm_wday);
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	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);
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	/* assume 20YY not 19YY */
	tmp = t->tm_year - 100;
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	buf[DS1307_REG_YEAR] = bin2bcd(tmp);
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	switch (ds1307->type) {
	case ds_1337:
	case ds_1339:
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	case ds_3231:
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		buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
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		break;
	case ds_1340:
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		buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
				| DS1340_BIT_CENTURY;
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		break;
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	case mcp7941x:
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		/*
		 * these bits were cleared when preparing the date/time
		 * values and need to be set again before writing the
		 * buffer out to the device.
		 */
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		buf[DS1307_REG_SECS] |= MCP7941X_BIT_ST;
		buf[DS1307_REG_WDAY] |= MCP7941X_BIT_VBATEN;
		break;
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	default:
		break;
	}
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	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]);

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	result = ds1307->write_block_data(ds1307->client,
		ds1307->offset, 7, buf);
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	if (result < 0) {
		dev_err(dev, "%s error %d\n", "write", result);
		return result;
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	}
	return 0;
}

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static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
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{
	struct i2c_client       *client = to_i2c_client(dev);
	struct ds1307		*ds1307 = i2c_get_clientdata(client);
	int			ret;

	if (!test_bit(HAS_ALARM, &ds1307->flags))
		return -EINVAL;

	/* read all ALARM1, ALARM2, and status registers at once */
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	ret = ds1307->read_block_data(client,
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			DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
	if (ret != 9) {
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		dev_err(dev, "%s error %d\n", "alarm read", ret);
		return -EIO;
	}

	dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
			"alarm read",
			ds1307->regs[0], ds1307->regs[1],
			ds1307->regs[2], ds1307->regs[3],
			ds1307->regs[4], ds1307->regs[5],
			ds1307->regs[6], ds1307->regs[7],
			ds1307->regs[8]);

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	/*
	 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
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	 * and that all four fields are checked matches
	 */
	t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
	t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
	t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
	t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
	t->time.tm_mon = -1;
	t->time.tm_year = -1;
	t->time.tm_wday = -1;
	t->time.tm_yday = -1;
	t->time.tm_isdst = -1;

	/* ... and status */
	t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
	t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);

	dev_dbg(dev, "%s secs=%d, mins=%d, "
		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
		"alarm read", t->time.tm_sec, t->time.tm_min,
		t->time.tm_hour, t->time.tm_mday,
		t->enabled, t->pending);

	return 0;
}

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static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
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{
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	struct i2c_client	*client = to_i2c_client(dev);
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	struct ds1307		*ds1307 = i2c_get_clientdata(client);
	unsigned char		*buf = ds1307->regs;
	u8			control, status;
	int			ret;

	if (!test_bit(HAS_ALARM, &ds1307->flags))
		return -EINVAL;

	dev_dbg(dev, "%s secs=%d, mins=%d, "
		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
		"alarm set", t->time.tm_sec, t->time.tm_min,
		t->time.tm_hour, t->time.tm_mday,
		t->enabled, t->pending);

	/* read current status of both alarms and the chip */
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	ret = ds1307->read_block_data(client,
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			DS1339_REG_ALARM1_SECS, 9, buf);
	if (ret != 9) {
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		dev_err(dev, "%s error %d\n", "alarm write", ret);
		return -EIO;
	}
	control = ds1307->regs[7];
	status = ds1307->regs[8];

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

	/* set ALARM1, using 24 hour and day-of-month modes */
	buf[0] = bin2bcd(t->time.tm_sec);
	buf[1] = bin2bcd(t->time.tm_min);
	buf[2] = bin2bcd(t->time.tm_hour);
	buf[3] = bin2bcd(t->time.tm_mday);

	/* set ALARM2 to non-garbage */
	buf[4] = 0;
	buf[5] = 0;
	buf[6] = 0;

	/* optionally enable ALARM1 */
	buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
	if (t->enabled) {
		dev_dbg(dev, "alarm IRQ armed\n");
		buf[7] |= DS1337_BIT_A1IE;	/* only ALARM1 is used */
	}
	buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);

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	ret = ds1307->write_block_data(client,
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			DS1339_REG_ALARM1_SECS, 9, buf);
	if (ret < 0) {
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		dev_err(dev, "can't set alarm time\n");
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		return ret;
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	}

	return 0;
}

521
static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
522 523 524 525 526
{
	struct i2c_client	*client = to_i2c_client(dev);
	struct ds1307		*ds1307 = i2c_get_clientdata(client);
	int			ret;

527 528
	if (!test_bit(HAS_ALARM, &ds1307->flags))
		return -ENOTTY;
529

530 531 532
	ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
	if (ret < 0)
		return ret;
533

534
	if (enabled)
535
		ret |= DS1337_BIT_A1IE;
536 537
	else
		ret &= ~DS1337_BIT_A1IE;
538

539 540 541
	ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
	if (ret < 0)
		return ret;
542 543 544 545

	return 0;
}

546
static const struct rtc_class_ops ds13xx_rtc_ops = {
547 548
	.read_time	= ds1307_get_time,
	.set_time	= ds1307_set_time,
549 550
	.read_alarm	= ds1337_read_alarm,
	.set_alarm	= ds1337_set_alarm,
551
	.alarm_irq_enable = ds1307_alarm_irq_enable,
552 553
};

D
David Brownell 已提交
554 555 556
/*----------------------------------------------------------------------*/

static ssize_t
557 558
ds1307_nvram_read(struct file *filp, struct kobject *kobj,
		struct bin_attribute *attr,
D
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559 560 561 562 563 564
		char *buf, loff_t off, size_t count)
{
	struct i2c_client	*client;
	struct ds1307		*ds1307;
	int			result;

F
frederic Rodo 已提交
565
	client = kobj_to_i2c_client(kobj);
D
David Brownell 已提交
566 567
	ds1307 = i2c_get_clientdata(client);

568
	if (unlikely(off >= ds1307->nvram->size))
D
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569
		return 0;
570 571
	if ((off + count) > ds1307->nvram->size)
		count = ds1307->nvram->size - off;
D
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572 573 574
	if (unlikely(!count))
		return count;

575 576
	result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
								count, buf);
577
	if (result < 0)
D
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578
		dev_err(&client->dev, "%s error %d\n", "nvram read", result);
579
	return result;
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580 581 582
}

static ssize_t
583 584
ds1307_nvram_write(struct file *filp, struct kobject *kobj,
		struct bin_attribute *attr,
D
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585 586 587
		char *buf, loff_t off, size_t count)
{
	struct i2c_client	*client;
E
Ed Swierk 已提交
588
	struct ds1307		*ds1307;
589
	int			result;
D
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590

F
frederic Rodo 已提交
591
	client = kobj_to_i2c_client(kobj);
E
Ed Swierk 已提交
592
	ds1307 = i2c_get_clientdata(client);
D
David Brownell 已提交
593

594
	if (unlikely(off >= ds1307->nvram->size))
D
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595
		return -EFBIG;
596 597
	if ((off + count) > ds1307->nvram->size)
		count = ds1307->nvram->size - off;
D
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598 599 600
	if (unlikely(!count))
		return count;

601 602
	result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
								count, buf);
603 604 605 606 607
	if (result < 0) {
		dev_err(&client->dev, "%s error %d\n", "nvram write", result);
		return result;
	}
	return count;
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608 609 610 611
}

/*----------------------------------------------------------------------*/

612 613
static int __devinit ds1307_probe(struct i2c_client *client,
				  const struct i2c_device_id *id)
614 615 616 617
{
	struct ds1307		*ds1307;
	int			err = -ENODEV;
	int			tmp;
618
	const struct chip_desc	*chip = &chips[id->driver_data];
619
	struct i2c_adapter	*adapter = to_i2c_adapter(client->dev.parent);
620
	int			want_irq = false;
621
	unsigned char		*buf;
W
Wolfram Sang 已提交
622 623 624 625 626
	static const int	bbsqi_bitpos[] = {
		[ds_1337] = 0,
		[ds_1339] = DS1339_BIT_BBSQI,
		[ds_3231] = DS3231_BIT_BBSQW,
	};
627

E
Ed Swierk 已提交
628 629
	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
	    && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
630 631
		return -EIO;

632 633
	ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL);
	if (!ds1307)
634
		return -ENOMEM;
D
David Brownell 已提交
635

636
	i2c_set_clientdata(client, ds1307);
J
Joakim Tjernlund 已提交
637 638 639 640

	ds1307->client	= client;
	ds1307->type	= id->driver_data;

641
	buf = ds1307->regs;
E
Ed Swierk 已提交
642 643 644 645 646 647 648
	if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
		ds1307->read_block_data = i2c_smbus_read_i2c_block_data;
		ds1307->write_block_data = i2c_smbus_write_i2c_block_data;
	} else {
		ds1307->read_block_data = ds1307_read_block_data;
		ds1307->write_block_data = ds1307_write_block_data;
	}
D
David Brownell 已提交
649 650 651 652

	switch (ds1307->type) {
	case ds_1337:
	case ds_1339:
W
Wolfram Sang 已提交
653
	case ds_3231:
654
		/* get registers that the "rtc" read below won't read... */
E
Ed Swierk 已提交
655
		tmp = ds1307->read_block_data(ds1307->client,
656
				DS1337_REG_CONTROL, 2, buf);
657 658 659 660 661 662
		if (tmp != 2) {
			pr_debug("read error %d\n", tmp);
			err = -EIO;
			goto exit_free;
		}

663 664
		/* oscillator off?  turn it on, so clock can tick. */
		if (ds1307->regs[0] & DS1337_BIT_nEOSC)
665 666
			ds1307->regs[0] &= ~DS1337_BIT_nEOSC;

667 668
		/*
		 * Using IRQ?  Disable the square wave and both alarms.
W
Wolfram Sang 已提交
669 670
		 * For some variants, be sure alarms can trigger when we're
		 * running on Vbackup (BBSQI/BBSQW)
671
		 */
672 673 674
		if (ds1307->client->irq > 0 && chip->alarm) {
			INIT_WORK(&ds1307->work, ds1307_work);

W
Wolfram Sang 已提交
675 676
			ds1307->regs[0] |= DS1337_BIT_INTCN
					| bbsqi_bitpos[ds1307->type];
677
			ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
678 679

			want_irq = true;
680 681 682 683
		}

		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
							ds1307->regs[0]);
684 685 686 687 688 689

		/* oscillator fault?  clear flag, and warn */
		if (ds1307->regs[1] & DS1337_BIT_OSF) {
			i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
				ds1307->regs[1] & ~DS1337_BIT_OSF);
			dev_warn(&client->dev, "SET TIME!\n");
690
		}
D
David Brownell 已提交
691
		break;
692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757

	case rx_8025:
		tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
				RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
		if (tmp != 2) {
			pr_debug("read error %d\n", tmp);
			err = -EIO;
			goto exit_free;
		}

		/* oscillator off?  turn it on, so clock can tick. */
		if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
			ds1307->regs[1] |= RX8025_BIT_XST;
			i2c_smbus_write_byte_data(client,
						  RX8025_REG_CTRL2 << 4 | 0x08,
						  ds1307->regs[1]);
			dev_warn(&client->dev,
				 "oscillator stop detected - SET TIME!\n");
		}

		if (ds1307->regs[1] & RX8025_BIT_PON) {
			ds1307->regs[1] &= ~RX8025_BIT_PON;
			i2c_smbus_write_byte_data(client,
						  RX8025_REG_CTRL2 << 4 | 0x08,
						  ds1307->regs[1]);
			dev_warn(&client->dev, "power-on detected\n");
		}

		if (ds1307->regs[1] & RX8025_BIT_VDET) {
			ds1307->regs[1] &= ~RX8025_BIT_VDET;
			i2c_smbus_write_byte_data(client,
						  RX8025_REG_CTRL2 << 4 | 0x08,
						  ds1307->regs[1]);
			dev_warn(&client->dev, "voltage drop detected\n");
		}

		/* make sure we are running in 24hour mode */
		if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
			u8 hour;

			/* switch to 24 hour mode */
			i2c_smbus_write_byte_data(client,
						  RX8025_REG_CTRL1 << 4 | 0x08,
						  ds1307->regs[0] |
						  RX8025_BIT_2412);

			tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
					RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
			if (tmp != 2) {
				pr_debug("read error %d\n", tmp);
				err = -EIO;
				goto exit_free;
			}

			/* correct hour */
			hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
			if (hour == 12)
				hour = 0;
			if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
				hour += 12;

			i2c_smbus_write_byte_data(client,
						  DS1307_REG_HOUR << 4 | 0x08,
						  hour);
		}
		break;
J
Joakim Tjernlund 已提交
758 759 760
	case ds_1388:
		ds1307->offset = 1; /* Seconds starts at 1 */
		break;
D
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761 762 763
	default:
		break;
	}
764 765 766

read_rtc:
	/* read RTC registers */
767
	tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
768
	if (tmp != 8) {
769 770 771 772 773
		pr_debug("read error %d\n", tmp);
		err = -EIO;
		goto exit_free;
	}

774 775
	/*
	 * minimal sanity checking; some chips (like DS1340) don't
776 777 778 779
	 * 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];
D
David Brownell 已提交
780 781 782
	switch (ds1307->type) {
	case ds_1307:
	case m41t00:
783
		/* clock halted?  turn it on, so clock can tick. */
D
David Brownell 已提交
784
		if (tmp & DS1307_BIT_CH) {
785 786
			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
			dev_warn(&client->dev, "SET TIME!\n");
D
David Brownell 已提交
787
			goto read_rtc;
788
		}
D
David Brownell 已提交
789
		break;
790 791
	case ds_1338:
		/* clock halted?  turn it on, so clock can tick. */
D
David Brownell 已提交
792
		if (tmp & DS1307_BIT_CH)
793 794 795 796 797
			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);

		/* oscillator fault?  clear flag, and warn */
		if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
			i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
798
					ds1307->regs[DS1307_REG_CONTROL]
799 800 801 802
					& ~DS1338_BIT_OSF);
			dev_warn(&client->dev, "SET TIME!\n");
			goto read_rtc;
		}
D
David Brownell 已提交
803
		break;
F
frederic Rodo 已提交
804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820
	case ds_1340:
		/* clock halted?  turn it on, so clock can tick. */
		if (tmp & DS1340_BIT_nEOSC)
			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);

		tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
		if (tmp < 0) {
			pr_debug("read error %d\n", tmp);
			err = -EIO;
			goto exit_free;
		}

		/* oscillator fault?  clear flag, and warn */
		if (tmp & DS1340_BIT_OSF) {
			i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
			dev_warn(&client->dev, "SET TIME!\n");
		}
821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
		break;
	case mcp7941x:
		/* make sure that the backup battery is enabled */
		if (!(ds1307->regs[DS1307_REG_WDAY] & MCP7941X_BIT_VBATEN)) {
			i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
					ds1307->regs[DS1307_REG_WDAY]
					| MCP7941X_BIT_VBATEN);
		}

		/* clock halted?  turn it on, so clock can tick. */
		if (!(tmp & MCP7941X_BIT_ST)) {
			i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
					MCP7941X_BIT_ST);
			dev_warn(&client->dev, "SET TIME!\n");
			goto read_rtc;
		}

F
frederic Rodo 已提交
838
		break;
839
	default:
D
David Brownell 已提交
840
		break;
841
	}
D
David Brownell 已提交
842

843
	tmp = ds1307->regs[DS1307_REG_HOUR];
844 845 846
	switch (ds1307->type) {
	case ds_1340:
	case m41t00:
847 848
		/*
		 * NOTE: ignores century bits; fix before deploying
849 850 851
		 * systems that will run through year 2100.
		 */
		break;
852 853
	case rx_8025:
		break;
854 855 856 857
	default:
		if (!(tmp & DS1307_BIT_12HR))
			break;

858 859
		/*
		 * Be sure we're in 24 hour mode.  Multi-master systems
860 861
		 * take note...
		 */
A
Adrian Bunk 已提交
862
		tmp = bcd2bin(tmp & 0x1f);
863 864 865 866
		if (tmp == 12)
			tmp = 0;
		if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
			tmp += 12;
867
		i2c_smbus_write_byte_data(client,
868
				ds1307->offset + DS1307_REG_HOUR,
A
Adrian Bunk 已提交
869
				bin2bcd(tmp));
870 871 872 873 874 875 876 877
	}

	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");
878
		goto exit_free;
879 880
	}

881
	if (want_irq) {
882
		err = request_irq(client->irq, ds1307_irq, IRQF_SHARED,
883 884 885 886 887 888
			  ds1307->rtc->name, client);
		if (err) {
			dev_err(&client->dev,
				"unable to request IRQ!\n");
			goto exit_irq;
		}
889 890

		device_set_wakeup_capable(&client->dev, 1);
891 892 893 894
		set_bit(HAS_ALARM, &ds1307->flags);
		dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
	}

895 896 897 898 899 900 901 902 903
	if (chip->nvram_size) {
		ds1307->nvram = kzalloc(sizeof(struct bin_attribute),
							GFP_KERNEL);
		if (!ds1307->nvram) {
			err = -ENOMEM;
			goto exit_nvram;
		}
		ds1307->nvram->attr.name = "nvram";
		ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
904
		sysfs_bin_attr_init(ds1307->nvram);
905 906 907 908 909 910 911 912
		ds1307->nvram->read = ds1307_nvram_read,
		ds1307->nvram->write = ds1307_nvram_write,
		ds1307->nvram->size = chip->nvram_size;
		ds1307->nvram_offset = chip->nvram_offset;
		err = sysfs_create_bin_file(&client->dev.kobj, ds1307->nvram);
		if (err) {
			kfree(ds1307->nvram);
			goto exit_nvram;
D
David Brownell 已提交
913
		}
914 915
		set_bit(HAS_NVRAM, &ds1307->flags);
		dev_info(&client->dev, "%zu bytes nvram\n", ds1307->nvram->size);
D
David Brownell 已提交
916 917
	}

918 919
	return 0;

920
exit_nvram:
921
exit_irq:
922
	rtc_device_unregister(ds1307->rtc);
923 924 925 926 927
exit_free:
	kfree(ds1307);
	return err;
}

928
static int __devexit ds1307_remove(struct i2c_client *client)
929
{
930
	struct ds1307 *ds1307 = i2c_get_clientdata(client);
931 932 933 934 935

	if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
		free_irq(client->irq, client);
		cancel_work_sync(&ds1307->work);
	}
936

937 938 939 940
	if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags)) {
		sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
		kfree(ds1307->nvram);
	}
D
David Brownell 已提交
941

942 943 944 945 946 947 948
	rtc_device_unregister(ds1307->rtc);
	kfree(ds1307);
	return 0;
}

static struct i2c_driver ds1307_driver = {
	.driver = {
949
		.name	= "rtc-ds1307",
950 951
		.owner	= THIS_MODULE,
	},
952 953
	.probe		= ds1307_probe,
	.remove		= __devexit_p(ds1307_remove),
954
	.id_table	= ds1307_id,
955 956
};

957
module_i2c_driver(ds1307_driver);
958 959 960

MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
MODULE_LICENSE("GPL");