staging:iio:ade7854: Rework SPI write function

The write operation using SPI has a many code duplications (similar to
I2C) and four different interfaces per data size. This patch introduces
a single function that centralizes the main task related to SPI.

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/staging/iio/meter/ade7854-spi.c b/drivers/staging/iio/meter/ade7854-spi.c
index 4419b8f06197e4a05ba284dbd54fa825606ee104..9c5c16c4d6e0d87a8ef2c70309298b924cde27eb 100644 (file)
--- a/drivers/staging/iio/meter/ade7854-spi.c
+++ b/drivers/staging/iio/meter/ade7854-spi.c
@@ -15,9 +15,10 @@
 #include <linux/iio/iio.h>
 #include "ade7854.h"
 
-static int ade7854_spi_write_reg_8(struct device *dev,
-                                  u16 reg_address,
-                                  u8 val)
+static int ade7854_spi_write_reg(struct device *dev,
+                                u16 reg_address,
+                                u32 val,
+                                int bits)
 {
        int ret;
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
@@ -32,93 +33,66 @@ static int ade7854_spi_write_reg_8(struct device *dev,
        st->tx[0] = ADE7854_WRITE_REG;
        st->tx[1] = (reg_address >> 8) & 0xFF;
        st->tx[2] = reg_address & 0xFF;
-       st->tx[3] = val & 0xFF;
+       switch (bits) {
+       case 8:
+               st->tx[3] = val & 0xFF;
+               break;
+       case 16:
+               xfer.len = 5;
+               st->tx[3] = (val >> 8) & 0xFF;
+               st->tx[4] = val & 0xFF;
+               break;
+       case 24:
+               xfer.len = 6;
+               st->tx[3] = (val >> 16) & 0xFF;
+               st->tx[4] = (val >> 8) & 0xFF;
+               st->tx[5] = val & 0xFF;
+               break;
+       case 32:
+               xfer.len = 7;
+               st->tx[3] = (val >> 24) & 0xFF;
+               st->tx[4] = (val >> 16) & 0xFF;
+               st->tx[5] = (val >> 8) & 0xFF;
+               st->tx[6] = val & 0xFF;
+               break;
+       default:
+               ret = -EINVAL;
+               goto unlock;
+       }
 
        ret = spi_sync_transfer(st->spi, &xfer, 1);
+unlock:
        mutex_unlock(&st->buf_lock);
 
        return ret;
 }
 
+static int ade7854_spi_write_reg_8(struct device *dev,
+                                  u16 reg_address,
+                                  u8 val)
+{
+       return ade7854_spi_write_reg(dev, reg_address, val, 8);
+}
+
 static int ade7854_spi_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);
-       struct spi_transfer xfer = {
-               .tx_buf = st->tx,
-               .bits_per_word = 8,
-               .len = 5,
-       };
-
-       mutex_lock(&st->buf_lock);
-       st->tx[0] = ADE7854_WRITE_REG;
-       st->tx[1] = (reg_address >> 8) & 0xFF;
-       st->tx[2] = reg_address & 0xFF;
-       st->tx[3] = (val >> 8) & 0xFF;
-       st->tx[4] = val & 0xFF;
-
-       ret = spi_sync_transfer(st->spi, &xfer, 1);
-       mutex_unlock(&st->buf_lock);
-
-       return ret;
+       return ade7854_spi_write_reg(dev, reg_address, val, 16);
 }
 
 static int ade7854_spi_write_reg_24(struct device *dev,
                                    u16 reg_address,
                                    u32 val)
 {
-       int ret;
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ade7854_state *st = iio_priv(indio_dev);
-       struct spi_transfer xfer = {
-               .tx_buf = st->tx,
-               .bits_per_word = 8,
-               .len = 6,
-       };
-
-       mutex_lock(&st->buf_lock);
-       st->tx[0] = ADE7854_WRITE_REG;
-       st->tx[1] = (reg_address >> 8) & 0xFF;
-       st->tx[2] = reg_address & 0xFF;
-       st->tx[3] = (val >> 16) & 0xFF;
-       st->tx[4] = (val >> 8) & 0xFF;
-       st->tx[5] = val & 0xFF;
-
-       ret = spi_sync_transfer(st->spi, &xfer, 1);
-       mutex_unlock(&st->buf_lock);
-
-       return ret;
+       return ade7854_spi_write_reg(dev, reg_address, val, 24);
 }
 
 static int ade7854_spi_write_reg_32(struct device *dev,
                                    u16 reg_address,
                                    u32 val)
 {
-       int ret;
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ade7854_state *st = iio_priv(indio_dev);
-       struct spi_transfer xfer = {
-               .tx_buf = st->tx,
-               .bits_per_word = 8,
-               .len = 7,
-       };
-
-       mutex_lock(&st->buf_lock);
-       st->tx[0] = ADE7854_WRITE_REG;
-       st->tx[1] = (reg_address >> 8) & 0xFF;
-       st->tx[2] = reg_address & 0xFF;
-       st->tx[3] = (val >> 24) & 0xFF;
-       st->tx[4] = (val >> 16) & 0xFF;
-       st->tx[5] = (val >> 8) & 0xFF;
-       st->tx[6] = val & 0xFF;
-
-       ret = spi_sync_transfer(st->spi, &xfer, 1);
-       mutex_unlock(&st->buf_lock);
-
-       return ret;
+       return ade7854_spi_write_reg(dev, reg_address, val, 32);
 }
 
 static int ade7854_spi_read_reg_8(struct device *dev,