[PATCH 2/7] staging:iio:ade7854: Rework SPI write function

From: Rodrigo Siqueira
Date: Wed Mar 14 2018 - 14:10:48 EST


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@xxxxxxxxx>
---
drivers/staging/iio/meter/ade7854-spi.c | 100 ++++++++++++++------------------
1 file changed, 45 insertions(+), 55 deletions(-)

diff --git a/drivers/staging/iio/meter/ade7854-spi.c b/drivers/staging/iio/meter/ade7854-spi.c
index 4419b8f06197..0dae118428cf 100644
--- 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,
+ enum data_size type)
{
int ret;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
@@ -32,36 +33,58 @@ 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 (type) {
+ case DATA_SIZE_8_BITS:
+ st->tx[3] = val & 0xFF;
+ break;
+ case DATA_SIZE_16_BITS:
+ xfer.len = 5;
+ st->tx[3] = (val >> 8) & 0xFF;
+ st->tx[4] = val & 0xFF;
+ break;
+ case DATA_SIZE_24_BITS:
+ xfer.len = 6;
+ st->tx[3] = (val >> 16) & 0xFF;
+ st->tx[4] = (val >> 8) & 0xFF;
+ st->tx[5] = val & 0xFF;
+ break;
+ case DATA_SIZE_32_BITS:
+ 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 error_spi_mutex_unlock;
+ }

ret = spi_sync_transfer(st->spi, &xfer, 1);
+error_spi_mutex_unlock:
mutex_unlock(&st->buf_lock);

return ret;
}

+static int ade7854_spi_write_reg_8(struct device *dev,
+ u16 reg_address,
+ u8 val)
+{
+ int ret;
+
+ ret = ade7854_spi_write_reg(dev, reg_address, val, DATA_SIZE_8_BITS);
+
+ return ret;
+}
+
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);
+ ret = ade7854_spi_write_reg(dev, reg_address, val, DATA_SIZE_16_BITS);

return ret;
}
@@ -71,24 +94,8 @@ static int ade7854_spi_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);
- 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);
+ ret = ade7854_spi_write_reg(dev, reg_address, val, DATA_SIZE_24_BITS);

return ret;
}
@@ -98,25 +105,8 @@ static int ade7854_spi_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);
- 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);
+ ret = ade7854_spi_write_reg(dev, reg_address, val, DATA_SIZE_32_BITS);

return ret;
}
--
2.16.2