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Commit d643a49a authored by Andreas Werner's avatar Andreas Werner Committed by Linus Torvalds
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drivers/rtc/rtc-rx8581.c: add SMBus-only adapters support 



Add support for SMBus-only adapters (e.g.  i2c-piix4).  The driver has
implemented only support for I2C adapters which implement the
I2C_FUNC_SMBUS_I2C_BLOCK functionality before.

With this patch it is possible to load and use the RTC driver with I2C and
SMBUS adapters like the rtc-ds1307 does.

Tested on AMD G Series Platform (i2c-piix4 adapter driver).

Signed-off-by: default avatarAndreas Werner <andreas.werner@men.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 11ba5a1e

drivers/rtc/rtc-rx8581.c

+68 −13
Original line number Diff line number Diff line
@@ -52,8 +52,45 @@ 
#define RX8581_CTRL_STOP	0x02 /* STOP bit */

#define RX8581_CTRL_RESET	0x01 /* RESET bit */



struct rx8581 {

	struct i2c_client	*client;

	struct rtc_device	*rtc;

	s32 (*read_block_data)(const struct i2c_client *client, u8 command,

				u8 length, u8 *values);

	s32 (*write_block_data)(const struct i2c_client *client, u8 command,

				u8 length, const u8 *values);

};



static struct i2c_driver rx8581_driver;



static int rx8581_read_block_data(const struct i2c_client *client, u8 command,

					u8 length, u8 *values)

{

	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;

}



static int rx8581_write_block_data(const struct i2c_client *client, u8 command,

					u8 length, const u8 *values)

{

	s32 i, ret;



	for (i = 0; i < length; i++) {

		ret = i2c_smbus_write_byte_data(client, command + i,

						values[i]);

		if (ret < 0)

			return ret;

	}

	return length;

}



/*

 * In the routines that deal directly with the rx8581 hardware, we use

 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
@@ -62,6 +99,7 @@ static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm) 
{

	unsigned char date[7];

	int data, err;

	struct rx8581 *rx8581 = i2c_get_clientdata(client);



	/* First we ensure that the "update flag" is not set, we read the

	 * time and date then re-read the "update flag". If the update flag
@@ -80,14 +118,13 @@ static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm) 
			err = i2c_smbus_write_byte_data(client,

				RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF));

			if (err != 0) {

				dev_err(&client->dev, "Unable to write device "

					"flags\n");

				dev_err(&client->dev, "Unable to write device flags\n");

				return -EIO;

			}

		}



		/* Now read time and date */

		err = i2c_smbus_read_i2c_block_data(client, RX8581_REG_SC,

		err = rx8581->read_block_data(client, RX8581_REG_SC,

			7, date);

		if (err < 0) {

			dev_err(&client->dev, "Unable to read date\n");
@@ -140,6 +177,7 @@ static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm) 
{

	int data, err;

	unsigned char buf[7];

	struct rx8581 *rx8581 = i2c_get_clientdata(client);



	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "

		"mday=%d, mon=%d, year=%d, wday=%d\n",
@@ -176,7 +214,7 @@ static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm) 
	}



	/* write register's data */

	err = i2c_smbus_write_i2c_block_data(client, RX8581_REG_SC, 7, buf);

	err = rx8581->write_block_data(client, RX8581_REG_SC, 7, buf);

	if (err < 0) {

		dev_err(&client->dev, "Unable to write to date registers\n");

		return -EIO;
@@ -231,22 +269,39 @@ static const struct rtc_class_ops rx8581_rtc_ops = { 
static int rx8581_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{

	struct rtc_device *rtc;

	struct rx8581	  *rx8581;



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



	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))

		return -ENODEV;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)

		&& !i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))

		return -EIO;



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

	rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL);

	if (!rx8581)

		return -ENOMEM;



	rtc = devm_rtc_device_register(&client->dev, rx8581_driver.driver.name,

					&rx8581_rtc_ops, THIS_MODULE);

	i2c_set_clientdata(client, rx8581);

	rx8581->client = client;



	if (IS_ERR(rtc))

		return PTR_ERR(rtc);

	if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {

		rx8581->read_block_data = i2c_smbus_read_i2c_block_data;

		rx8581->write_block_data = i2c_smbus_write_i2c_block_data;

	} else {

		rx8581->read_block_data = rx8581_read_block_data;

		rx8581->write_block_data = rx8581_write_block_data;

	}



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



	i2c_set_clientdata(client, rtc);

	rx8581->rtc = devm_rtc_device_register(&client->dev,

		rx8581_driver.driver.name, &rx8581_rtc_ops, THIS_MODULE);



	if (IS_ERR(rx8581->rtc)) {

		dev_err(&client->dev,

			"unable to register the class device\n");

		return PTR_ERR(rx8581->rtc);

	}



	return 0;

}