[PATCH 1/7] rtc: rx8581: switch to rtc_register_device

[PATCH 1/7] rtc: rx8581: switch to rtc_register_device

[Alexandre Belloni]

This allows for future improvement of the driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-rx8581.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index 32caadf912ca..c64911a08531 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -286,16 +286,13 @@ static int rx8581_probe(struct i2c_client *client,
 		rx8581->write_block_data = rx8581_write_block_data;
 	}
 
-	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");
+	rx8581->rtc = devm_rtc_allocate_device(&client->dev);
+	if (IS_ERR(rx8581->rtc))
 		return PTR_ERR(rx8581->rtc);
-	}
 
-	return 0;
+	rx8581->rtc->ops = &rx8581_rtc_ops;
+
+	return rtc_register_device(rx8581->rtc);
 }
 
 static const struct i2c_device_id rx8581_id[] = {
-- 
2.17.0

[PATCH 2/7] rtc: rx8581: add RTC range

[Alexandre Belloni]

The rx8581 can support dates from 01/01/2000 to 31/12/2099.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-rx8581.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index c64911a08531..c5ffd30ca672 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -291,6 +291,8 @@ static int rx8581_probe(struct i2c_client *client,
 		return PTR_ERR(rx8581->rtc);
 
 	rx8581->rtc->ops = &rx8581_rtc_ops;
+	rx8581->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rx8581->rtc->range_max = RTC_TIMESTAMP_END_2099;
 
 	return rtc_register_device(rx8581->rtc);
 }
-- 
2.17.0

[PATCH 3/7] rtc: rx8581: let the core handle rtc range

[Alexandre Belloni]

Let the core handle offsetting and windowing the RTC range.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-rx8581.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index c5ffd30ca672..171ee241bd2f 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -153,10 +153,7 @@ static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 	tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
 	tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
 	tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
-	tm->tm_year = bcd2bin(date[RX8581_REG_YR]);
-	if (tm->tm_year < 70)
-		tm->tm_year += 100;	/* assume we are in 1970...2069 */
-
+	tm->tm_year = bcd2bin(date[RX8581_REG_YR]) + 100;
 
 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 		"mday=%d, mon=%d, year=%d, wday=%d\n",
@@ -190,7 +187,7 @@ static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 	buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);
 
 	/* year and century */
-	buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100);
+	buf[RX8581_REG_YR] = bin2bcd(tm->tm_year - 100);
 	buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);
 
 	/* Stop the clock */
@@ -293,6 +290,8 @@ static int rx8581_probe(struct i2c_client *client,
 	rx8581->rtc->ops = &rx8581_rtc_ops;
 	rx8581->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 	rx8581->rtc->range_max = RTC_TIMESTAMP_END_2099;
+	rx8581->rtc->start_secs = 0;
+	rx8581->rtc->set_start_time = true;
 
 	return rtc_register_device(rx8581->rtc);
 }
-- 
2.17.0

[PATCH 4/7] rtc: rx8581: remove useless indirection

[Alexandre Belloni]

rx8581_get_datetime and rx8581_set_datetime are only used after casting dev
to an i2c_client. Remove that useless indirection.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-rx8581.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index 171ee241bd2f..a91fbb86a110 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -93,8 +93,9 @@ static int rx8581_write_block_data(const struct i2c_client *client, u8 command,
  * In the routines that deal directly with the rx8581 hardware, we use
  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
  */
-static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm)
+static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
+	struct i2c_client *client = to_i2c_client(dev);
 	unsigned char date[7];
 	int data, err;
 	struct rx8581 *rx8581 = i2c_get_clientdata(client);
@@ -164,8 +165,9 @@ static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 	return 0;
 }
 
-static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm)
+static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
+	struct i2c_client *client = to_i2c_client(dev);
 	int data, err;
 	unsigned char buf[7];
 	struct rx8581 *rx8581 = i2c_get_clientdata(client);
@@ -242,16 +244,6 @@ static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 	return 0;
 }
 
-static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
-{
-	return rx8581_get_datetime(to_i2c_client(dev), tm);
-}
-
-static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
-{
-	return rx8581_set_datetime(to_i2c_client(dev), tm);
-}
-
 static const struct rtc_class_ops rx8581_rtc_ops = {
 	.read_time	= rx8581_rtc_read_time,
 	.set_time	= rx8581_rtc_set_time,
-- 
2.17.0

[PATCH 5/7] rtc: rx8581: remove useless declaration

[Alexandre Belloni]

The rx8581_driver forward declaration is useless, remove it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-rx8581.c | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index a91fbb86a110..0a70f1ac5cc2 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -59,8 +59,6 @@ struct rx8581 {
 				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)
 {
@@ -107,7 +105,7 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	 */
 	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
 	if (data < 0) {
-		dev_err(&client->dev, "Unable to read device flags\n");
+		dev_err(dev, "Unable to read device flags\n");
 		return -EIO;
 	}
 
@@ -117,7 +115,7 @@ static int rx8581_rtc_read_time(struct device *dev, 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(dev, "Unable to write device flags\n");
 				return -EIO;
 			}
 		}
@@ -126,24 +124,23 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 		err = rx8581->read_block_data(client, RX8581_REG_SC,
 			7, date);
 		if (err < 0) {
-			dev_err(&client->dev, "Unable to read date\n");
+			dev_err(dev, "Unable to read date\n");
 			return -EIO;
 		}
 
 		/* Check flag register */
 		data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
 		if (data < 0) {
-			dev_err(&client->dev, "Unable to read device flags\n");
+			dev_err(dev, "Unable to read device flags\n");
 			return -EIO;
 		}
 	} while (data & RX8581_FLAG_UF);
 
 	if (data & RX8581_FLAG_VLF)
-		dev_info(&client->dev,
+		dev_info(dev,
 			"low voltage detected, date/time is not reliable.\n");
 
-	dev_dbg(&client->dev,
-		"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
+	dev_dbg(dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
 		"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
 		__func__,
 		date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
@@ -156,7 +153,7 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
 	tm->tm_year = bcd2bin(date[RX8581_REG_YR]) + 100;
 
-	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 		"mday=%d, mon=%d, year=%d, wday=%d\n",
 		__func__,
 		tm->tm_sec, tm->tm_min, tm->tm_hour,
@@ -172,7 +169,7 @@ static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	unsigned char buf[7];
 	struct rx8581 *rx8581 = i2c_get_clientdata(client);
 
-	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
+	dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
 		"mday=%d, mon=%d, year=%d, wday=%d\n",
 		__func__,
 		tm->tm_sec, tm->tm_min, tm->tm_hour,
@@ -195,49 +192,49 @@ static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	/* Stop the clock */
 	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
 	if (data < 0) {
-		dev_err(&client->dev, "Unable to read control register\n");
+		dev_err(dev, "Unable to read control register\n");
 		return -EIO;
 	}
 
 	err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
 		(data | RX8581_CTRL_STOP));
 	if (err < 0) {
-		dev_err(&client->dev, "Unable to write control register\n");
+		dev_err(dev, "Unable to write control register\n");
 		return -EIO;
 	}
 
 	/* write register's data */
 	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");
+		dev_err(dev, "Unable to write to date registers\n");
 		return -EIO;
 	}
 
 	/* get VLF and clear it */
 	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
 	if (data < 0) {
-		dev_err(&client->dev, "Unable to read flag register\n");
+		dev_err(dev, "Unable to read flag register\n");
 		return -EIO;
 	}
 
 	err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
 		(data & ~(RX8581_FLAG_VLF)));
 	if (err != 0) {
-		dev_err(&client->dev, "Unable to write flag register\n");
+		dev_err(dev, "Unable to write flag register\n");
 		return -EIO;
 	}
 
 	/* Restart the clock */
 	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
 	if (data < 0) {
-		dev_err(&client->dev, "Unable to read control register\n");
+		dev_err(dev, "Unable to read control register\n");
 		return -EIO;
 	}
 
 	err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
 		(data & ~(RX8581_CTRL_STOP)));
 	if (err != 0) {
-		dev_err(&client->dev, "Unable to write control register\n");
+		dev_err(dev, "Unable to write control register\n");
 		return -EIO;
 	}
 
-- 
2.17.0

[PATCH 6/7] rtc: rx8581: error out when time invalid

[Alexandre Belloni]

Return an error when the date is unreliable because the battery is low.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-rx8581.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index 0a70f1ac5cc2..53644bb271af 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -109,6 +109,12 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 		return -EIO;
 	}
 
+	if (data & RX8581_FLAG_VLF) {
+		dev_warn(dev,
+			"low voltage detected, date/time is not reliable.\n");
+		return -EINVAL;
+	}
+
 	do {
 		/* If update flag set, clear it */
 		if (data & RX8581_FLAG_UF) {
@@ -136,10 +142,6 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 		}
 	} while (data & RX8581_FLAG_UF);
 
-	if (data & RX8581_FLAG_VLF)
-		dev_info(dev,
-			"low voltage detected, date/time is not reliable.\n");
-
 	dev_dbg(dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
 		"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
 		__func__,
-- 
2.17.0

[PATCH 7/7] rtc: rx8581: switch to regmap

[Alexandre Belloni]

Switch to regmap to simplify handling block read/write.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-rx8581.c | 155 +++++++++++----------------------------
 1 file changed, 42 insertions(+), 113 deletions(-)

diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index 53644bb271af..0e0546e5c541 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/bcd.h>
+#include <linux/regmap.h>
 #include <linux/rtc.h>
 #include <linux/log2.h>
 
@@ -51,42 +52,10 @@
 #define RX8581_CTRL_RESET	0x01 /* RESET bit */
 
 struct rx8581 {
-	struct i2c_client	*client;
+	struct regmap		*regmap;
 	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 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.
@@ -95,7 +64,8 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	unsigned char date[7];
-	int data, err;
+	unsigned int data;
+	int err;
 	struct rx8581 *rx8581 = i2c_get_clientdata(client);
 
 	/* First we ensure that the "update flag" is not set, we read the
@@ -103,11 +73,9 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	 * has been set, we know that the time has changed during the read so
 	 * we repeat the whole process again.
 	 */
-	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
-	if (data < 0) {
-		dev_err(dev, "Unable to read device flags\n");
-		return -EIO;
-	}
+	err = regmap_read(rx8581->regmap, RX8581_REG_FLAG, &data);
+	if (err < 0)
+		return err;
 
 	if (data & RX8581_FLAG_VLF) {
 		dev_warn(dev,
@@ -118,28 +86,22 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	do {
 		/* If update flag set, clear it */
 		if (data & RX8581_FLAG_UF) {
-			err = i2c_smbus_write_byte_data(client,
-				RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF));
-			if (err != 0) {
-				dev_err(dev, "Unable to write device flags\n");
-				return -EIO;
-			}
+			err = regmap_write(rx8581->regmap, RX8581_REG_FLAG,
+					  data & ~RX8581_FLAG_UF);
+			if (err < 0)
+				return err;
 		}
 
 		/* Now read time and date */
-		err = rx8581->read_block_data(client, RX8581_REG_SC,
-			7, date);
-		if (err < 0) {
-			dev_err(dev, "Unable to read date\n");
-			return -EIO;
-		}
+		err = regmap_bulk_read(rx8581->regmap, RX8581_REG_SC, date,
+				       sizeof(date));
+		if (err < 0)
+			return err;
 
 		/* Check flag register */
-		data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
-		if (data < 0) {
-			dev_err(dev, "Unable to read device flags\n");
-			return -EIO;
-		}
+		err = regmap_read(rx8581->regmap, RX8581_REG_FLAG, &data);
+		if (err < 0)
+			return err;
 	} while (data & RX8581_FLAG_UF);
 
 	dev_dbg(dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
@@ -167,7 +129,7 @@ static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	int data, err;
+	int err;
 	unsigned char buf[7];
 	struct rx8581 *rx8581 = i2c_get_clientdata(client);
 
@@ -192,55 +154,26 @@ static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);
 
 	/* Stop the clock */
-	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
-	if (data < 0) {
-		dev_err(dev, "Unable to read control register\n");
-		return -EIO;
-	}
-
-	err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
-		(data | RX8581_CTRL_STOP));
-	if (err < 0) {
-		dev_err(dev, "Unable to write control register\n");
-		return -EIO;
-	}
+	err = regmap_update_bits(rx8581->regmap, RX8581_REG_CTRL,
+				 RX8581_CTRL_STOP, RX8581_CTRL_STOP);
+	if (err < 0)
+		return err;
 
 	/* write register's data */
-	err = rx8581->write_block_data(client, RX8581_REG_SC, 7, buf);
-	if (err < 0) {
-		dev_err(dev, "Unable to write to date registers\n");
-		return -EIO;
-	}
+	err = regmap_bulk_write(rx8581->regmap, RX8581_REG_SC,
+				buf, sizeof(buf));
+	if (err < 0)
+		return err;
 
 	/* get VLF and clear it */
-	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
-	if (data < 0) {
-		dev_err(dev, "Unable to read flag register\n");
-		return -EIO;
-	}
-
-	err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
-		(data & ~(RX8581_FLAG_VLF)));
-	if (err != 0) {
-		dev_err(dev, "Unable to write flag register\n");
-		return -EIO;
-	}
+	err = regmap_update_bits(rx8581->regmap, RX8581_REG_FLAG,
+				 RX8581_FLAG_VLF, 0);
+	if (err < 0)
+		return err;
 
 	/* Restart the clock */
-	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
-	if (data < 0) {
-		dev_err(dev, "Unable to read control register\n");
-		return -EIO;
-	}
-
-	err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
-		(data & ~(RX8581_CTRL_STOP)));
-	if (err != 0) {
-		dev_err(dev, "Unable to write control register\n");
-		return -EIO;
-	}
-
-	return 0;
+	return regmap_update_bits(rx8581->regmap, RX8581_REG_CTRL,
+				 RX8581_CTRL_STOP, 0);
 }
 
 static const struct rtc_class_ops rx8581_rtc_ops = {
@@ -252,27 +185,23 @@ static int rx8581_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct rx8581	  *rx8581;
+	static const struct regmap_config config = {
+		.reg_bits = 8,
+		.val_bits = 8,
+		.max_register = 0xf,
+	};
 
 	dev_dbg(&client->dev, "%s\n", __func__);
 
-	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)
-		&& !i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
-		return -EIO;
-
 	rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL);
 	if (!rx8581)
 		return -ENOMEM;
 
 	i2c_set_clientdata(client, rx8581);
-	rx8581->client = client;
-
-	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;
-	}
+
+	rx8581->regmap = devm_regmap_init_i2c(client, &config);
+	if (IS_ERR(rx8581->regmap))
+		return PTR_ERR(rx8581->regmap);
 
 	rx8581->rtc = devm_rtc_allocate_device(&client->dev);
 	if (IS_ERR(rx8581->rtc))
-- 
2.17.0