staging:iio:ade7854: Rework I2C read function

The read operation for the I2C function has many duplications that can
be generalized into a single function. This patch reworks the read
operation for I2C to centralizes all similar code in a single function.

It is possible to remove all the old interface to use the new one,
however, for keeping the things simple and working this patch maintain
legacy interface.

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-i2c.c b/drivers/staging/iio/meter/ade7854-i2c.c
index 29e959f..63793f9 100644 (file)
--- a/drivers/staging/iio/meter/ade7854-i2c.c
+++ b/drivers/staging/iio/meter/ade7854-i2c.c
@@ -65,9 +65,10 @@ unlock:
        return ret < 0 ? ret : 0;
 }
 
-static int ade7854_i2c_read_reg_8(struct device *dev,
-                                 u16 reg_address,
-                                 u8 *val)
+static int ade7854_i2c_read_reg(struct device *dev,
+                               u16 reg_address,
+                               u32 *val,
+                               int bits)
 {
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct ade7854_state *st = iio_priv(indio_dev);
@@ -79,95 +80,62 @@ static int ade7854_i2c_read_reg_8(struct device *dev,
 
        ret = i2c_master_send(st->i2c, st->tx, 2);
        if (ret < 0)
-               goto out;
+               goto unlock;
 
-       ret = i2c_master_recv(st->i2c, st->rx, 1);
+       ret = i2c_master_recv(st->i2c, st->rx, bits);
        if (ret < 0)
-               goto out;
+               goto unlock;
+
+       switch (bits) {
+       case 8:
+               *val = st->rx[0];
+               break;
+       case 16:
+               *val = (st->rx[0] << 8) | st->rx[1];
+               break;
+       case 24:
+               *val = (st->rx[0] << 16) | (st->rx[1] << 8) | st->rx[2];
+               break;
+       case 32:
+               *val = (st->rx[0] << 24) | (st->rx[1] << 16) |
+                       (st->rx[2] << 8) | st->rx[3];
+               break;
+       default:
+               ret = -EINVAL;
+               goto unlock;
+       }
 
-       *val = st->rx[0];
-out:
+unlock:
        mutex_unlock(&st->buf_lock);
        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)
 {
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ade7854_state *st = iio_priv(indio_dev);
-       int ret;
-
-       mutex_lock(&st->buf_lock);
-       st->tx[0] = (reg_address >> 8) & 0xFF;
-       st->tx[1] = reg_address & 0xFF;
-
-       ret = i2c_master_send(st->i2c, st->tx, 2);
-       if (ret < 0)
-               goto out;
-
-       ret = i2c_master_recv(st->i2c, st->rx, 2);
-       if (ret < 0)
-               goto out;
-
-       *val = (st->rx[0] << 8) | st->rx[1];
-out:
-       mutex_unlock(&st->buf_lock);
-       return ret;
+       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)
 {
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ade7854_state *st = iio_priv(indio_dev);
-       int ret;
-
-       mutex_lock(&st->buf_lock);
-       st->tx[0] = (reg_address >> 8) & 0xFF;
-       st->tx[1] = reg_address & 0xFF;
-
-       ret = i2c_master_send(st->i2c, st->tx, 2);
-       if (ret < 0)
-               goto out;
-
-       ret = i2c_master_recv(st->i2c, st->rx, 3);
-       if (ret < 0)
-               goto out;
-
-       *val = (st->rx[0] << 16) | (st->rx[1] << 8) | st->rx[2];
-out:
-       mutex_unlock(&st->buf_lock);
-       return ret;
+       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)
 {
-       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-       struct ade7854_state *st = iio_priv(indio_dev);
-       int ret;
-
-       mutex_lock(&st->buf_lock);
-       st->tx[0] = (reg_address >> 8) & 0xFF;
-       st->tx[1] = reg_address & 0xFF;
-
-       ret = i2c_master_send(st->i2c, st->tx, 2);
-       if (ret < 0)
-               goto out;
-
-       ret = i2c_master_recv(st->i2c, st->rx, 4);
-       if (ret < 0)
-               goto out;
-
-       *val = (st->rx[0] << 24) | (st->rx[1] << 16) |
-               (st->rx[2] << 8) | st->rx[3];
-out:
-       mutex_unlock(&st->buf_lock);
-       return ret;
+       return ade7854_i2c_read_reg(dev, reg_address, (u32 *)val, 32);
 }
 
 static int ade7854_i2c_probe(struct i2c_client *client,