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Commit c065f35c authored by David Brownell's avatar David Brownell Committed by Linus Torvalds
Browse files

rtc-ds1307 becomes new-style i2c driver 



Convert the rtc-ds1307 driver into a "new style" driver.

Also improve probe() checks:  be more correct about switching out of
AM/PM mode, and issue a (debug) diagnostic when failing due to bogus
register values.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Andrew Victor <andrew@sanpeople.com>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent be5f59f4

drivers/rtc/rtc-ds1307.c

+53 −75
Original line number Diff line number Diff line
@@ -27,13 +27,8 @@ 
 * 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,
@@ -43,11 +38,6 @@ enum ds_type { 
	// 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 */
@@ -55,6 +45,8 @@ I2C_CLIENT_INSMOD; 
#	define DS1340_BIT_nEOSC		0x80

#define DS1307_REG_MIN		0x01	/* 00-59 */

#define DS1307_REG_HOUR		0x02	/* 00-23, or 1-12{am,pm} */

#	define DS1307_BIT_12HR		0x40	/* in REG_HOUR */

#	define DS1307_BIT_PM		0x20	/* in REG_HOUR */

#	define DS1340_BIT_CENTURY_EN	0x80	/* in REG_HOUR */

#	define DS1340_BIT_CENTURY	0x40	/* in REG_HOUR */

#define DS1307_REG_WDAY		0x03	/* 01-07 */
@@ -252,39 +244,27 @@ static const struct rtc_class_ops ds13xx_rtc_ops = { 


static struct i2c_driver ds1307_driver;



static int __devinit

ds1307_detect(struct i2c_adapter *adapter, int address, int kind)

static int __devinit ds1307_probe(struct i2c_client *client)

{

	struct ds1307		*ds1307;

	int			err = -ENODEV;

	struct i2c_client	*client;

	int			tmp;

	const struct chip_desc	*chip;

	struct i2c_adapter	*adapter = to_i2c_adapter(client->dev.parent);



	if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) {

		err = -ENOMEM;

		goto exit;

	chip = find_chip(client->name);

	if (!chip) {

		dev_err(&client->dev, "unknown chip type '%s'\n",

				client->name);

		return -ENODEV;

	}



	/* 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);

	if (!i2c_check_functionality(adapter,

			I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))

		return -EIO;



	if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))

		return -ENOMEM;



	ds1307->client = client;

	i2c_set_clientdata(client, ds1307);
@@ -378,94 +358,92 @@ read_rtc: 
			goto read_rtc;

		}

		break;

	default:

	case ds_1337:

	case ds_1339:

		break;

	}



	tmp = ds1307->regs[DS1307_REG_SECS];

	tmp = BCD2BIN(tmp & 0x7f);

	if (tmp > 60)

		goto exit_free;

		goto exit_bad;

	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);

	if (tmp > 60)

		goto exit_free;

		goto exit_bad;



	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);

	if (tmp == 0 || tmp > 31)

		goto exit_free;

		goto exit_bad;



	tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f);

	if (tmp == 0 || tmp > 12)

		goto exit_free;

		goto exit_bad;



	/* 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.

	 * The clock needs to be reset after changing it, too...

	 */

	tmp = ds1307->regs[DS1307_REG_HOUR];

	if (tmp & (1 << 6)) {

		if (tmp & (1 << 5))

			tmp = BCD2BIN(tmp & 0x1f) + 12;

		else

			tmp = BCD2BIN(tmp);

	switch (ds1307->type) {

	case ds_1340:

	case m41t00:

		/* NOTE: ignores century bits; fix before deploying

		 * systems that will run through year 2100.

		 */

		break;

	default:

		if (!(tmp & DS1307_BIT_12HR))

			break;



		/* Be sure we're in 24 hour mode.  Multi-master systems

		 * take note...

		 */

		tmp = BCD2BIN(tmp & 0x1f);

		if (tmp == 12)

			tmp = 0;

		if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)

			tmp += 12;

		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;

		goto exit_free;

	}



	return 0;



exit_detach:

	i2c_detach_client(client);

exit_bad:

	dev_dbg(&client->dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",

			"bogus register",

			ds1307->regs[0], ds1307->regs[1],

			ds1307->regs[2], ds1307->regs[3],

			ds1307->regs[4], ds1307->regs[5],

			ds1307->regs[6]);



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)

static int __devexit ds1307_remove(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",

		.name	= "rtc-ds1307",

		.owner	= THIS_MODULE,

	},

	.attach_adapter	= ds1307_attach_adapter,

	.detach_client	= __devexit_p(ds1307_detach_client),

	.probe		= ds1307_probe,

	.remove		= __devexit_p(ds1307_remove),

};



static int __init ds1307_init(void)