staging:iio:ade7854: Remove read_reg_* duplications

The original code had a read function per data size; after updates, all
read functions tasks were centralized in a single function, but the old
signature was kept to maintain the module working without problems. This
patch removes a set of duplications associated with read_reg_*, and
update the areas that calling the old interface by the new one.

Signed-off-by: Rodrigo Siqueira <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/staging/iio/meter/ade7854-i2c.c

···
 	return ret;
 }
 
-static int ade7854_i2c_read_reg_8(struct device *dev,
-				  u16 reg_address,
-				  u8 *val)
-{
-	return ade7854_i2c_read_reg(dev, reg_address, (u32 *)val, 8);
-}
-
-static int ade7854_i2c_read_reg_16(struct device *dev,
-				   u16 reg_address,
-				   u16 *val)
-{
-	return ade7854_i2c_read_reg(dev, reg_address, (u32 *)val, 16);
-}
-
-static int ade7854_i2c_read_reg_24(struct device *dev,
-				   u16 reg_address,
-				   u32 *val)
-{
-	return ade7854_i2c_read_reg(dev, reg_address, (u32 *)val, 24);
-}
-
-static int ade7854_i2c_read_reg_32(struct device *dev,
-				   u16 reg_address,
-				   u32 *val)
-{
-	return ade7854_i2c_read_reg(dev, reg_address, (u32 *)val, 32);
-}
-
 static int ade7854_i2c_probe(struct i2c_client *client,
 			     const struct i2c_device_id *id)
 {
···
 		return -ENOMEM;
 	st = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
-	st->read_reg_8 = ade7854_i2c_read_reg_8;
-	st->read_reg_16 = ade7854_i2c_read_reg_16;
-	st->read_reg_24 = ade7854_i2c_read_reg_24;
-	st->read_reg_32 = ade7854_i2c_read_reg_32;
+	st->read_reg = ade7854_i2c_read_reg;
 	st->write_reg = ade7854_i2c_write_reg;
 	st->i2c = client;
 	st->irq = client->irq;

drivers/staging/iio/meter/ade7854-spi.c

···
 	st->tx[2] = reg_address & 0xFF;
 
 	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
-	if (ret) {
+	if (ret < 0) {
 		dev_err(&st->spi->dev, "problem when reading register 0x%02X",
 			reg_address);
 		goto unlock;
···
 	return ret;
 }
 
-static int ade7854_spi_read_reg_8(struct device *dev,
-				  u16 reg_address,
-				  u8 *val)
-{
-	return ade7854_spi_read_reg(dev, reg_address, (u32 *)val, 8);
-}
-
-static int ade7854_spi_read_reg_16(struct device *dev,
-				   u16 reg_address,
-				   u16 *val)
-{
-	return ade7854_spi_read_reg(dev, reg_address, (u32 *)val, 16);
-}
-
-static int ade7854_spi_read_reg_24(struct device *dev,
-				   u16 reg_address,
-				   u32 *val)
-{
-	return ade7854_spi_read_reg(dev, reg_address, (u32 *)val, 24);
-}
-
-static int ade7854_spi_read_reg_32(struct device *dev,
-				   u16 reg_address,
-				   u32 *val)
-{
-	return ade7854_spi_read_reg(dev, reg_address, (u32 *)val, 32);
-}
-
 static int ade7854_spi_probe(struct spi_device *spi)
 {
 	struct ade7854_state *st;
···
 		return -ENOMEM;
 	st = iio_priv(indio_dev);
 	spi_set_drvdata(spi, indio_dev);
-	st->read_reg_8 = ade7854_spi_read_reg_8;
-	st->read_reg_16 = ade7854_spi_read_reg_16;
-	st->read_reg_24 = ade7854_spi_read_reg_24;
-	st->read_reg_32 = ade7854_spi_read_reg_32;
+	st->read_reg = ade7854_spi_read_reg;
 	st->write_reg = ade7854_spi_write_reg;
 	st->irq = spi->irq;
 	st->spi = spi;

drivers/staging/iio/meter/ade7854.c

···
 				 char *buf)
 {
 	int ret;
-	u8 val = 0;
+	u32 val = 0;
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ade7854_state *st = iio_priv(indio_dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
-	ret = st->read_reg_8(dev, this_attr->address, &val);
+	ret = st->read_reg(dev, this_attr->address, &val, 8);
 	if (ret < 0)
 		return ret;
 
···
 				  char *buf)
 {
 	int ret;
-	u16 val = 0;
+	u32 val = 0;
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ade7854_state *st = iio_priv(indio_dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
-	ret = st->read_reg_16(dev, this_attr->address, &val);
+	ret = st->read_reg(dev, this_attr->address, &val, 16);
 	if (ret < 0)
 		return ret;
 
···
 	struct ade7854_state *st = iio_priv(indio_dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
-	ret = st->read_reg_24(dev, this_attr->address, &val);
+	ret = st->read_reg(dev, this_attr->address, &val, 24);
 	if (ret < 0)
 		return ret;
 
···
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ade7854_state *st = iio_priv(indio_dev);
 
-	ret = st->read_reg_32(dev, this_attr->address, &val);
+	ret = st->read_reg(dev, this_attr->address, &val, 32);
 	if (ret < 0)
 		return ret;
 
···
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ade7854_state *st = iio_priv(indio_dev);
-	u16 val;
+	u32 val;
 
-	st->read_reg_16(dev, ADE7854_CONFIG, &val);
+	st->read_reg(dev, ADE7854_CONFIG, &val, 16);
 	val |= BIT(7); /* Software Chip Reset */
 
 	return st->write_reg(dev, ADE7854_CONFIG, val, 16);
···
 	int ret;
 	u32 irqen;
 
-	ret = st->read_reg_32(dev, ADE7854_MASK0, &irqen);
+	ret = st->read_reg(dev, ADE7854_MASK0, &irqen, 32);
 	if (ret < 0)
 		return ret;
 

drivers/staging/iio/meter/ade7854.h

···
 /**
  * struct ade7854_state - device instance specific data
  * @spi:		actual spi_device
+ * @read_reg		Wrapper function for I2C and SPI read
  * @write_reg		Wrapper function for I2C and SPI write
  * @indio_dev:		industrial I/O device structure
  * @buf_lock:		mutex to protect tx and rx
···
 struct ade7854_state {
 	struct spi_device *spi;
 	struct i2c_client *i2c;
-	int (*read_reg_8)(struct device *dev, u16 reg_address, u8 *val);
-	int (*read_reg_16)(struct device *dev, u16 reg_address, u16 *val);
-	int (*read_reg_24)(struct device *dev, u16 reg_address, u32 *val);
-	int (*read_reg_32)(struct device *dev, u16 reg_address, u32 *val);
+	int (*read_reg)(struct device *dev, u16 reg_address, u32 *val,
+			int bits);
 	int (*write_reg)(struct device *dev, u16 reg_address, u32 val,
 			 int bits);
 	int irq;