[PATCH 1/7] staging:iio:ade7854: Rework I2C write function

[Rodrigo Siqueira]

The write operation using I2C has many code duplications and four
different interfaces per data size. This patch introduces a single
function that centralizes the main tasks.

The central function inserted by this patch can easily replace all the
four functions related to the data size. However, this patch does not
remove any code signature for keeping the meter module work and make
easier to review this patch.

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@xxxxxxxxx>
---
 drivers/staging/iio/meter/ade7854-i2c.c | 89 +++++++++++++++++++--------------
 drivers/staging/iio/meter/ade7854.h     |  7 +++
 2 files changed, 58 insertions(+), 38 deletions(-)

diff --git a/drivers/staging/iio/meter/ade7854-i2c.c b/drivers/staging/iio/meter/ade7854-i2c.c
index 317e4f0d8176..03133a05eae4 100644
--- a/drivers/staging/iio/meter/ade7854-i2c.c
+++ b/drivers/staging/iio/meter/ade7854-i2c.c
@@ -15,41 +15,74 @@
 #include <linux/iio/iio.h>
 #include "ade7854.h"
 
-static int ade7854_i2c_write_reg_8(struct device *dev,
-				   u16 reg_address,
-				   u8 val)
+static int ade7854_i2c_write_reg(struct device *dev,
+				 u16 reg_address,
+				 u32 val,
+				 enum data_size type)
 {
 	int ret;
+	int count;
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ade7854_state *st = iio_priv(indio_dev);
 
 	mutex_lock(&st->buf_lock);
 	st->tx[0] = (reg_address >> 8) & 0xFF;
 	st->tx[1] = reg_address & 0xFF;
-	st->tx[2] = val;
 
-	ret = i2c_master_send(st->i2c, st->tx, 3);
+	switch (type) {
+	case DATA_SIZE_8_BITS:
+		st->tx[2] = val & 0xFF;
+		count = 3;
+		break;
+	case DATA_SIZE_16_BITS:
+		st->tx[2] = (val >> 8) & 0xFF;
+		st->tx[3] = val & 0xFF;
+		count = 4;
+		break;
+	case DATA_SIZE_24_BITS:
+		st->tx[2] = (val >> 16) & 0xFF;
+		st->tx[3] = (val >> 8) & 0xFF;
+		st->tx[4] = val & 0xFF;
+		count = 5;
+		break;
+	case DATA_SIZE_32_BITS:
+		st->tx[2] = (val >> 24) & 0xFF;
+		st->tx[3] = (val >> 16) & 0xFF;
+		st->tx[4] = (val >> 8) & 0xFF;
+		st->tx[5] = val & 0xFF;
+		count = 6;
+		break;
+	default:
+		ret = -EINVAL;
+		goto error_i2c_write_unlock;
+	}
+
+	ret = i2c_master_send(st->i2c, st->tx, count);
+
+error_i2c_write_unlock:
 	mutex_unlock(&st->buf_lock);
 
 	return ret;
 }
 
+static int ade7854_i2c_write_reg_8(struct device *dev,
+				   u16 reg_address,
+				   u8 val)
+{
+	int ret;
+
+	ret = ade7854_i2c_write_reg(dev, reg_address, val, DATA_SIZE_8_BITS);
+
+	return ret;
+}
+
 static int ade7854_i2c_write_reg_16(struct device *dev,
 				    u16 reg_address,
 				    u16 val)
 {
 	int ret;
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct ade7854_state *st = iio_priv(indio_dev);
 
-	mutex_lock(&st->buf_lock);
-	st->tx[0] = (reg_address >> 8) & 0xFF;
-	st->tx[1] = reg_address & 0xFF;
-	st->tx[2] = (val >> 8) & 0xFF;
-	st->tx[3] = val & 0xFF;
-
-	ret = i2c_master_send(st->i2c, st->tx, 4);
-	mutex_unlock(&st->buf_lock);
+	ret = ade7854_i2c_write_reg(dev, reg_address, val, DATA_SIZE_16_BITS);
 
 	return ret;
 }
@@ -59,18 +92,8 @@ static int ade7854_i2c_write_reg_24(struct device *dev,
 				    u32 val)
 {
 	int ret;
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct ade7854_state *st = iio_priv(indio_dev);
 
-	mutex_lock(&st->buf_lock);
-	st->tx[0] = (reg_address >> 8) & 0xFF;
-	st->tx[1] = reg_address & 0xFF;
-	st->tx[2] = (val >> 16) & 0xFF;
-	st->tx[3] = (val >> 8) & 0xFF;
-	st->tx[4] = val & 0xFF;
-
-	ret = i2c_master_send(st->i2c, st->tx, 5);
-	mutex_unlock(&st->buf_lock);
+	ret = ade7854_i2c_write_reg(dev, reg_address, val, DATA_SIZE_24_BITS);
 
 	return ret;
 }
@@ -80,23 +103,13 @@ static int ade7854_i2c_write_reg_32(struct device *dev,
 				    u32 val)
 {
 	int ret;
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct ade7854_state *st = iio_priv(indio_dev);
-
-	mutex_lock(&st->buf_lock);
-	st->tx[0] = (reg_address >> 8) & 0xFF;
-	st->tx[1] = reg_address & 0xFF;
-	st->tx[2] = (val >> 24) & 0xFF;
-	st->tx[3] = (val >> 16) & 0xFF;
-	st->tx[4] = (val >> 8) & 0xFF;
-	st->tx[5] = val & 0xFF;
 
-	ret = i2c_master_send(st->i2c, st->tx, 6);
-	mutex_unlock(&st->buf_lock);
+	ret = ade7854_i2c_write_reg(dev, reg_address, val, DATA_SIZE_32_BITS);
 
 	return ret;
 }
 
+
 static int ade7854_i2c_read_reg_8(struct device *dev,
 				  u16 reg_address,
 				  u8 *val)
diff --git a/drivers/staging/iio/meter/ade7854.h b/drivers/staging/iio/meter/ade7854.h
index a82d38224cbd..71bdd638f348 100644
--- a/drivers/staging/iio/meter/ade7854.h
+++ b/drivers/staging/iio/meter/ade7854.h
@@ -143,6 +143,13 @@
 #define ADE7854_SPI_BURST	(u32)(1000 * 1000)
 #define ADE7854_SPI_FAST	(u32)(2000 * 1000)
 
+enum data_size {
+	DATA_SIZE_8_BITS = 1,
+	DATA_SIZE_16_BITS,
+	DATA_SIZE_24_BITS,
+	DATA_SIZE_32_BITS,
+};
+
 /**
  * struct ade7854_state - device instance specific data
  * @spi:			actual spi_device
-- 
2.16.2