add regmap API support to hts221 iio driver

Move duplicated i2c/spi probe code in hts221_probe()

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 drivers/iio/humidity/hts221.h      |  3 ++-
 drivers/iio/humidity/hts221_core.c | 18 ++++++++++++++++--
 drivers/iio/humidity/hts221_i2c.c  | 18 ++----------------
 drivers/iio/humidity/hts221_spi.c  | 18 ++----------------
 4 files changed, 22 insertions(+), 35 deletions(-)

drivers/iio/humidity/hts221.h +2 -1

index 51d021966222..c581af8c0f5d 100644
@@ -61,7 +61,8 @@ struct hts221_hw {
 extern const struct dev_pm_ops hts221_pm_ops;
 
 int hts221_write_with_mask(struct hts221_hw *hw, u8 addr, u8 mask, u8 val);
-int hts221_probe(struct iio_dev *iio_dev);
+int hts221_probe(struct device *dev, int irq, const char *name,
+		 const struct hts221_transfer_function *tf_ops);
 int hts221_set_enable(struct hts221_hw *hw, bool enable);
 int hts221_allocate_buffers(struct hts221_hw *hw);
 int hts221_allocate_trigger(struct hts221_hw *hw);

drivers/iio/humidity/hts221_core.c +16 -2

index daef177219b6..d3f7904766bd 100644
@@ -581,12 +581,26 @@ static const struct iio_info hts221_info = {
 
 static const unsigned long hts221_scan_masks[] = {0x3, 0x0};
 
-int hts221_probe(struct iio_dev *iio_dev)
+int hts221_probe(struct device *dev, int irq, const char *name,
+		 const struct hts221_transfer_function *tf_ops)
 {
-	struct hts221_hw *hw = iio_priv(iio_dev);
+	struct iio_dev *iio_dev;
+	struct hts221_hw *hw;
 	int err;
 	u8 data;
 
+	iio_dev = devm_iio_device_alloc(dev, sizeof(*hw));
+	if (!iio_dev)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, (void *)iio_dev);
+
+	hw = iio_priv(iio_dev);
+	hw->name = name;
+	hw->dev = dev;
+	hw->irq = irq;
+	hw->tf = tf_ops;
+
 	mutex_init(&hw->lock);
 
 	err = hts221_check_whoami(hw);

drivers/iio/humidity/hts221_i2c.c +2 -16

index f38e4b7e0160..2c97350a0f76 100644
@@ -66,22 +66,8 @@ static const struct hts221_transfer_function hts221_transfer_fn = {
 static int hts221_i2c_probe(struct i2c_client *client,
 			    const struct i2c_device_id *id)
 {
-	struct hts221_hw *hw;
-	struct iio_dev *iio_dev;
-
-	iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*hw));
-	if (!iio_dev)
-		return -ENOMEM;
-
-	i2c_set_clientdata(client, iio_dev);
-
-	hw = iio_priv(iio_dev);
-	hw->name = client->name;
-	hw->dev = &client->dev;
-	hw->irq = client->irq;
-	hw->tf = &hts221_transfer_fn;
-
-	return hts221_probe(iio_dev);
+	return hts221_probe(&client->dev, client->irq,
+			    client->name, &hts221_transfer_fn);
 }
 
 static const struct acpi_device_id hts221_acpi_match[] = {

drivers/iio/humidity/hts221_spi.c +2 -16

index 57cbc256771b..55b29b53b9d1 100644
@@ -80,22 +80,8 @@ static const struct hts221_transfer_function hts221_transfer_fn = {
 
 static int hts221_spi_probe(struct spi_device *spi)
 {
-	struct hts221_hw *hw;
-	struct iio_dev *iio_dev;
-
-	iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*hw));
-	if (!iio_dev)
-		return -ENOMEM;
-
-	spi_set_drvdata(spi, iio_dev);
-
-	hw = iio_priv(iio_dev);
-	hw->name = spi->modalias;
-	hw->dev = &spi->dev;
-	hw->irq = spi->irq;
-	hw->tf = &hts221_transfer_fn;
-
-	return hts221_probe(iio_dev);
+	return hts221_probe(&spi->dev, spi->irq,
+			    spi->modalias, &hts221_transfer_fn);
 }
 
 static const struct of_device_id hts221_spi_of_match[] = {

Introduce regmap API support to access to i2c/spi bus instead of using a custom support.
Remove lock mutex since concurrency is already managed by regmap API

Signed-off-by Lorenzo Bianconi <[email protected]>

---
 drivers/iio/humidity/Kconfig         |   2 +
 drivers/iio/humidity/hts221.h        |  21 +------
 drivers/iio/humidity/hts221_buffer.c |  37 +++++------
 drivers/iio/humidity/hts221_core.c   | 115 +++++++++++++----------------------
 drivers/iio/humidity/hts221_i2c.c    |  64 ++++++-------------
 drivers/iio/humidity/hts221_spi.c    |  81 ++++++------------------
 6 files changed, 103 insertions(+), 217 deletions(-)

drivers/iio/humidity/Kconfig +2 -0

index 2c0fc9a400b8..1a0d458e4f4e 100644
@@ -68,10 +68,12 @@ config HTS221
 config HTS221_I2C
 	tristate
 	depends on HTS221
+	select REGMAP_I2C
 
 config HTS221_SPI
 	tristate
 	depends on HTS221
+	select REGMAP_SPI
 
 config HTU21
 	tristate "Measurement Specialties HTU21 humidity & temperature sensor"

drivers/iio/humidity/hts221.h +2 -19

index c581af8c0f5d..e41a3d83e95d 100644
@@ -15,21 +15,8 @@
 
 #include <linux/iio/iio.h>
 
-#define HTS221_RX_MAX_LENGTH	8
-#define HTS221_TX_MAX_LENGTH	8
-
 #define HTS221_DATA_SIZE	2
 
-struct hts221_transfer_buffer {
-	u8 rx_buf[HTS221_RX_MAX_LENGTH];
-	u8 tx_buf[HTS221_TX_MAX_LENGTH] ____cacheline_aligned;
-};
-
-struct hts221_transfer_function {
-	int (*read)(struct device *dev, u8 addr, int len, u8 *data);
-	int (*write)(struct device *dev, u8 addr, int len, u8 *data);
-};
-
 enum hts221_sensor_type {
 	HTS221_SENSOR_H,
 	HTS221_SENSOR_T,

@@ -44,8 +31,8 @@ struct hts221_sensor {
 struct hts221_hw {
 	const char *name;
 	struct device *dev;
+	struct regmap *regmap;
 
-	struct mutex lock;
 	struct iio_trigger *trig;
 	int irq;
 

@@ -53,16 +40,12 @@ struct hts221_hw {
 
 	bool enabled;
 	u8 odr;
-
-	const struct hts221_transfer_function *tf;
-	struct hts221_transfer_buffer tb;
 };
 
 extern const struct dev_pm_ops hts221_pm_ops;
 
-int hts221_write_with_mask(struct hts221_hw *hw, u8 addr, u8 mask, u8 val);
 int hts221_probe(struct device *dev, int irq, const char *name,
-		 const struct hts221_transfer_function *tf_ops);
+		 struct regmap *regmap);
 int hts221_set_enable(struct hts221_hw *hw, bool enable);
 int hts221_allocate_buffers(struct hts221_hw *hw);
 int hts221_allocate_trigger(struct hts221_hw *hw);

drivers/iio/humidity/hts221_buffer.c +19 -18

index e971ea425268..29e0e9c1491a 100644
@@ -12,6 +12,8 @@
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/irqreturn.h>
+#include <linux/regmap.h>
+#include <linux/bitfield.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/trigger.h>

@@ -38,12 +40,10 @@ static int hts221_trig_set_state(struct iio_trigger *trig, bool state)
 {
 	struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig);
 	struct hts221_hw *hw = iio_priv(iio_dev);
-	int err;
-
-	err = hts221_write_with_mask(hw, HTS221_REG_DRDY_EN_ADDR,
-				     HTS221_REG_DRDY_EN_MASK, state);
 
-	return err < 0 ? err : 0;
+	return regmap_update_bits(hw->regmap, HTS221_REG_DRDY_EN_ADDR,
+				  HTS221_REG_DRDY_EN_MASK,
+				  FIELD_PREP(HTS221_REG_DRDY_EN_MASK, state));
 }
 
 static const struct iio_trigger_ops hts221_trigger_ops = {

@@ -53,11 +53,9 @@ static const struct iio_trigger_ops hts221_trigger_ops = {
 static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
 {
 	struct hts221_hw *hw = private;
-	u8 status;
-	int err;
+	int err, status;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_STATUS_ADDR, sizeof(status),
-			   &status);
+	err = regmap_read(hw->regmap, HTS221_REG_STATUS_ADDR, &status);
 	if (err < 0)
 		return IRQ_HANDLED;
 

@@ -102,8 +100,10 @@ int hts221_allocate_trigger(struct hts221_hw *hw)
 		break;
 	}
 
-	err = hts221_write_with_mask(hw, HTS221_REG_DRDY_HL_ADDR,
-				     HTS221_REG_DRDY_HL_MASK, irq_active_low);
+	err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_HL_ADDR,
+				 HTS221_REG_DRDY_HL_MASK,
+				 FIELD_PREP(HTS221_REG_DRDY_HL_MASK,
+					    irq_active_low));
 	if (err < 0)
 		return err;
 

@@ -114,9 +114,10 @@ int hts221_allocate_trigger(struct hts221_hw *hw)
 		open_drain = true;
 	}
 
-	err = hts221_write_with_mask(hw, HTS221_REG_DRDY_PP_OD_ADDR,
-				     HTS221_REG_DRDY_PP_OD_MASK,
-				     open_drain);
+	err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_PP_OD_ADDR,
+				 HTS221_REG_DRDY_PP_OD_MASK,
+				 FIELD_PREP(HTS221_REG_DRDY_PP_OD_MASK,
+					    open_drain));
 	if (err < 0)
 		return err;
 

@@ -171,15 +172,15 @@ static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
 
 	/* humidity data */
 	ch = &iio_dev->channels[HTS221_SENSOR_H];
-	err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
-			   buffer);
+	err = regmap_bulk_read(hw->regmap, ch->address,
+			       buffer, HTS221_DATA_SIZE);
 	if (err < 0)
 		goto out;
 
 	/* temperature data */
 	ch = &iio_dev->channels[HTS221_SENSOR_T];
-	err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
-			   buffer + HTS221_DATA_SIZE);
+	err = regmap_bulk_read(hw->regmap, ch->address,
+			       buffer + HTS221_DATA_SIZE, HTS221_DATA_SIZE);
 	if (err < 0)
 		goto out;
 

drivers/iio/humidity/hts221_core.c +0 -0

index d3f7904766bd..75d442e7b510 100644

drivers/iio/humidity/hts221_core.c +43 -72

+#include <linux/regmap.h>
+#include <linux/bitfield.h>
 
 #include "hts221.h"
 

@@ -131,38 +133,11 @@ static const struct iio_chan_spec hts221_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(2),
 };
 
-int hts221_write_with_mask(struct hts221_hw *hw, u8 addr, u8 mask, u8 val)
-{
-	u8 data;
-	int err;
-
-	mutex_lock(&hw->lock);
-
-	err = hw->tf->read(hw->dev, addr, sizeof(data), &data);
-	if (err < 0) {
-		dev_err(hw->dev, "failed to read %02x register\n", addr);
-		goto unlock;
-	}
-
-	data = (data & ~mask) | ((val << __ffs(mask)) & mask);
-
-	err = hw->tf->write(hw->dev, addr, sizeof(data), &data);
-	if (err < 0)
-		dev_err(hw->dev, "failed to write %02x register\n", addr);
-
-unlock:
-	mutex_unlock(&hw->lock);
-
-	return err;
-}
-
 static int hts221_check_whoami(struct hts221_hw *hw)
 {
-	u8 data;
-	int err;
+	int err, data;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_WHOAMI_ADDR, sizeof(data),
-			   &data);
+	err = regmap_read(hw->regmap, HTS221_REG_WHOAMI_ADDR, &data);
 	if (err < 0) {
 		dev_err(hw->dev, "failed to read whoami register\n");
 		return err;

@@ -188,8 +163,10 @@ static int hts221_update_odr(struct hts221_hw *hw, u8 odr)
 	if (i == ARRAY_SIZE(hts221_odr_table))
 		return -EINVAL;
 
-	err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
-				     HTS221_ODR_MASK, hts221_odr_table[i].val);
+	err = regmap_update_bits(hw->regmap, HTS221_REG_CNTRL1_ADDR,
+				 HTS221_ODR_MASK,
+				 FIELD_PREP(HTS221_ODR_MASK,
+					    hts221_odr_table[i].val));
 	if (err < 0)
 		return err;
 

@@ -202,8 +179,8 @@ static int hts221_update_avg(struct hts221_hw *hw,
 			     enum hts221_sensor_type type,
 			     u16 val)
 {
-	int i, err;
 	const struct hts221_avg *avg = &hts221_avg_list[type];
+	int i, err, data;
 
 	for (i = 0; i < HTS221_AVG_DEPTH; i++)
 		if (avg->avg_avl[i] == val)

@@ -212,7 +189,9 @@ static int hts221_update_avg(struct hts221_hw *hw,
 	if (i == HTS221_AVG_DEPTH)
 		return -EINVAL;
 
-	err = hts221_write_with_mask(hw, avg->addr, avg->mask, i);
+	data = ((i << __ffs(avg->mask)) & avg->mask);
+	err = regmap_update_bits(hw->regmap, avg->addr,
+				 avg->mask, data);
 	if (err < 0)
 		return err;
 

@@ -274,8 +253,9 @@ int hts221_set_enable(struct hts221_hw *hw, bool enable)
 {
 	int err;
 
-	err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
-				     HTS221_ENABLE_MASK, enable);
+	err = regmap_update_bits(hw->regmap, HTS221_REG_CNTRL1_ADDR,
+				 HTS221_ENABLE_MASK,
+				 FIELD_PREP(HTS221_ENABLE_MASK, enable));
 	if (err < 0)
 		return err;
 

@@ -286,35 +266,31 @@ int hts221_set_enable(struct hts221_hw *hw, bool enable)
 
 static int hts221_parse_temp_caldata(struct hts221_hw *hw)
 {
-	int err, *slope, *b_gen;
+	int err, *slope, *b_gen, cal0, cal1;
 	s16 cal_x0, cal_x1, cal_y0, cal_y1;
-	u8 cal0, cal1;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_0T_CAL_Y_H,
-			   sizeof(cal0), &cal0);
+	err = regmap_read(hw->regmap, HTS221_REG_0T_CAL_Y_H, &cal0);
 	if (err < 0)
 		return err;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_T1_T0_CAL_Y_H,
-			   sizeof(cal1), &cal1);
+	err = regmap_read(hw->regmap, HTS221_REG_T1_T0_CAL_Y_H, &cal1);
 	if (err < 0)
 		return err;
 	cal_y0 = (le16_to_cpu(cal1 & 0x3) << 8) | cal0;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_1T_CAL_Y_H,
-			   sizeof(cal0), &cal0);
+	err = regmap_read(hw->regmap, HTS221_REG_1T_CAL_Y_H, &cal0);
 	if (err < 0)
 		return err;
 	cal_y1 = (((cal1 & 0xc) >> 2) << 8) | cal0;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_0T_CAL_X_L, sizeof(cal_x0),
-			   (u8 *)&cal_x0);
+	err = regmap_bulk_read(hw->regmap, HTS221_REG_0T_CAL_X_L,
+			       &cal_x0, sizeof(cal_x0));
 	if (err < 0)
 		return err;
 	cal_x0 = le16_to_cpu(cal_x0);
 
-	err = hw->tf->read(hw->dev, HTS221_REG_1T_CAL_X_L, sizeof(cal_x1),
-			   (u8 *)&cal_x1);
+	err = regmap_bulk_read(hw->regmap, HTS221_REG_1T_CAL_X_L,
+			       &cal_x1, sizeof(cal_x1));
 	if (err < 0)
 		return err;
 	cal_x1 = le16_to_cpu(cal_x1);

@@ -332,30 +308,27 @@ static int hts221_parse_temp_caldata(struct hts221_hw *hw)
 
 static int hts221_parse_rh_caldata(struct hts221_hw *hw)
 {
-	int err, *slope, *b_gen;
+	int err, *slope, *b_gen, data;
 	s16 cal_x0, cal_x1, cal_y0, cal_y1;
-	u8 data;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_0RH_CAL_Y_H, sizeof(data),
-			   &data);
+	err = regmap_read(hw->regmap, HTS221_REG_0RH_CAL_Y_H, &data);
 	if (err < 0)
 		return err;
 	cal_y0 = data;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_1RH_CAL_Y_H, sizeof(data),
-			   &data);
+	err = regmap_read(hw->regmap, HTS221_REG_1RH_CAL_Y_H, &data);
 	if (err < 0)
 		return err;
 	cal_y1 = data;
 
-	err = hw->tf->read(hw->dev, HTS221_REG_0RH_CAL_X_H, sizeof(cal_x0),
-			   (u8 *)&cal_x0);
+	err = regmap_bulk_read(hw->regmap, HTS221_REG_0RH_CAL_X_H,
+			       &cal_x0, sizeof(cal_x0));
 	if (err < 0)
 		return err;
 	cal_x0 = le16_to_cpu(cal_x0);
 
-	err = hw->tf->read(hw->dev, HTS221_REG_1RH_CAL_X_H, sizeof(cal_x1),
-			   (u8 *)&cal_x1);
+	err = regmap_bulk_read(hw->regmap, HTS221_REG_1RH_CAL_X_H,
+			       &cal_x1, sizeof(cal_x1));
 	if (err < 0)
 		return err;
 	cal_x1 = le16_to_cpu(cal_x1);

@@ -440,7 +413,7 @@ static int hts221_read_oneshot(struct hts221_hw *hw, u8 addr, int *val)
 
 	msleep(50);
 
-	err = hw->tf->read(hw->dev, addr, sizeof(data), data);
+	err = regmap_bulk_read(hw->regmap, addr, data, sizeof(data));
 	if (err < 0)
 		return err;
 

@@ -582,7 +555,7 @@ static const struct iio_info hts221_info = {
 static const unsigned long hts221_scan_masks[] = {0x3, 0x0};
 
 int hts221_probe(struct device *dev, int irq, const char *name,
-		 const struct hts221_transfer_function *tf_ops)
+		 struct regmap *regmap)
 {
 	struct iio_dev *iio_dev;
 	struct hts221_hw *hw;

@@ -599,9 +572,7 @@ int hts221_probe(struct device *dev, int irq, const char *name,
 	hw->name = name;
 	hw->dev = dev;
 	hw->irq = irq;
-	hw->tf = tf_ops;
-
-	mutex_init(&hw->lock);
+	hw->regmap = regmap;
 
 	err = hts221_check_whoami(hw);
 	if (err < 0)

@@ -616,8 +587,9 @@ int hts221_probe(struct device *dev, int irq, const char *name,
 	iio_dev->info = &hts221_info;
 
 	/* enable Block Data Update */
-	err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
-				     HTS221_BDU_MASK, 1);
+	err = regmap_update_bits(hw->regmap, HTS221_REG_CNTRL1_ADDR,
+				 HTS221_BDU_MASK,
+				 FIELD_PREP(HTS221_BDU_MASK, 1));
 	if (err < 0)
 		return err;
 

@@ -673,12 +645,10 @@ static int __maybe_unused hts221_suspend(struct device *dev)
 {
 	struct iio_dev *iio_dev = dev_get_drvdata(dev);
 	struct hts221_hw *hw = iio_priv(iio_dev);
-	int err;
 
-	err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
-				     HTS221_ENABLE_MASK, false);
-
-	return err < 0 ? err : 0;
+	return regmap_update_bits(hw->regmap, HTS221_REG_CNTRL1_ADDR,
+				  HTS221_ENABLE_MASK,
+				  FIELD_PREP(HTS221_ENABLE_MASK, false));
 }
 
 static int __maybe_unused hts221_resume(struct device *dev)

@@ -688,9 +658,10 @@ static int __maybe_unused hts221_resume(struct device *dev)
 	int err = 0;
 
 	if (hw->enabled)
-		err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
-					     HTS221_ENABLE_MASK, true);
-
+		err = regmap_update_bits(hw->regmap, HTS221_REG_CNTRL1_ADDR,
+					 HTS221_ENABLE_MASK,
+					 FIELD_PREP(HTS221_ENABLE_MASK,
+						    true));
 	return err;
 }
 

drivers/iio/humidity/hts221_i2c.c +18 -46

index 2c97350a0f76..b5b3f408a658 100644
@@ -13,61 +13,33 @@
 #include <linux/acpi.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
-#include "hts221.h"
-
-#define I2C_AUTO_INCREMENT	0x80
-
-static int hts221_i2c_read(struct device *dev, u8 addr, int len, u8 *data)
-{
-	struct i2c_msg msg[2];
-	struct i2c_client *client = to_i2c_client(dev);
-
-	if (len > 1)
-		addr |= I2C_AUTO_INCREMENT;
-
-	msg[0].addr = client->addr;
-	msg[0].flags = client->flags;
-	msg[0].len = 1;
-	msg[0].buf = &addr;
-
-	msg[1].addr = client->addr;
-	msg[1].flags = client->flags | I2C_M_RD;
-	msg[1].len = len;
-	msg[1].buf = data;
-
-	return i2c_transfer(client->adapter, msg, 2);
-}
+#include <linux/regmap.h>
 
-static int hts221_i2c_write(struct device *dev, u8 addr, int len, u8 *data)
-{
-	u8 send[len + 1];
-	struct i2c_msg msg;
-	struct i2c_client *client = to_i2c_client(dev);
-
-	if (len > 1)
-		addr |= I2C_AUTO_INCREMENT;
-
-	send[0] = addr;
-	memcpy(&send[1], data, len * sizeof(u8));
-
-	msg.addr = client->addr;
-	msg.flags = client->flags;
-	msg.len = len + 1;
-	msg.buf = send;
+#include "hts221.h"
 
-	return i2c_transfer(client->adapter, &msg, 1);
-}
+#define HTS221_I2C_AUTO_INCREMENT	BIT(7)
 
-static const struct hts221_transfer_function hts221_transfer_fn = {
-	.read = hts221_i2c_read,
-	.write = hts221_i2c_write,
+static const struct regmap_config hts221_i2c_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.write_flag_mask = HTS221_I2C_AUTO_INCREMENT,
+	.read_flag_mask = HTS221_I2C_AUTO_INCREMENT,
 };
 
 static int hts221_i2c_probe(struct i2c_client *client,
 			    const struct i2c_device_id *id)
 {
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_i2c(client, &hts221_i2c_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Failed to register i2c regmap %d\n",
+			(int)PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
 	return hts221_probe(&client->dev, client->irq,
-			    client->name, &hts221_transfer_fn);
+			    client->name, regmap);
 }
 
 static const struct acpi_device_id hts221_acpi_match[] = {

drivers/iio/humidity/hts221_spi.c +19 -62

index 55b29b53b9d1..9c005f037026 100644
@@ -12,76 +12,33 @@
 #include <linux/module.h>
 #include <linux/spi/spi.h>
 #include <linux/slab.h>
-#include "hts221.h"
-
-#define SENSORS_SPI_READ	0x80
-#define SPI_AUTO_INCREMENT	0x40
-
-static int hts221_spi_read(struct device *dev, u8 addr, int len, u8 *data)
-{
-	int err;
-	struct spi_device *spi = to_spi_device(dev);
-	struct iio_dev *iio_dev = spi_get_drvdata(spi);
-	struct hts221_hw *hw = iio_priv(iio_dev);
-
-	struct spi_transfer xfers[] = {
-		{
-			.tx_buf = hw->tb.tx_buf,
-			.bits_per_word = 8,
-			.len = 1,
-		},
-		{
-			.rx_buf = hw->tb.rx_buf,
-			.bits_per_word = 8,
-			.len = len,
-		}
-	};
-
-	if (len > 1)
-		addr |= SPI_AUTO_INCREMENT;
-	hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ;
-
-	err = spi_sync_transfer(spi, xfers,  ARRAY_SIZE(xfers));
-	if (err < 0)
-		return err;
-
-	memcpy(data, hw->tb.rx_buf, len * sizeof(u8));
-
-	return len;
-}
-
-static int hts221_spi_write(struct device *dev, u8 addr, int len, u8 *data)
-{
-	struct spi_device *spi = to_spi_device(dev);
-	struct iio_dev *iio_dev = spi_get_drvdata(spi);
-	struct hts221_hw *hw = iio_priv(iio_dev);
-
-	struct spi_transfer xfers = {
-		.tx_buf = hw->tb.tx_buf,
-		.bits_per_word = 8,
-		.len = len + 1,
-	};
-
-	if (len >= HTS221_TX_MAX_LENGTH)
-		return -ENOMEM;
+#include <linux/regmap.h>
 
-	if (len > 1)
-		addr |= SPI_AUTO_INCREMENT;
-	hw->tb.tx_buf[0] = addr;
-	memcpy(&hw->tb.tx_buf[1], data, len);
+#include "hts221.h"
 
-	return spi_sync_transfer(spi, &xfers, 1);
-}
+#define HTS221_SPI_READ			BIT(7)
+#define HTS221_SPI_AUTO_INCREMENT	BIT(6)
 
-static const struct hts221_transfer_function hts221_transfer_fn = {
-	.read = hts221_spi_read,
-	.write = hts221_spi_write,
+static const struct regmap_config hts221_spi_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.write_flag_mask = HTS221_SPI_AUTO_INCREMENT,
+	.read_flag_mask = HTS221_SPI_READ | HTS221_SPI_AUTO_INCREMENT,
 };
 
 static int hts221_spi_probe(struct spi_device *spi)
 {
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_spi(spi, &hts221_spi_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Failed to register spi regmap %d\n",
+			(int)PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
 	return hts221_probe(&spi->dev, spi->irq,
-			    spi->modalias, &hts221_transfer_fn);
+			    spi->modalias, regmap);
 }
 
 static const struct of_device_id hts221_spi_of_match[] = {