Re: [PATCH v3 6/8] staging:iio:ade7854: Rework I2C read function

[Jonathan Cameron]

On Fri, 23 Mar 2018 11:26:57 -0300
Rodrigo Siqueira <rodrigosiqueiramelo@xxxxxxxxx> wrote:

> 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@xxxxxxxxx>
Applied, thanks.

Jonathan

> ---
> Changes in v3:
>  - Remove the use of defines that not improve the readability
>  - Replace variable name "bytes" for "bits"
>  - Update commit message
> 
>  drivers/staging/iio/meter/ade7854-i2c.c | 106 +++++++++++---------------------
>  1 file changed, 37 insertions(+), 69 deletions(-)
> 
> diff --git a/drivers/staging/iio/meter/ade7854-i2c.c b/drivers/staging/iio/meter/ade7854-i2c.c
> index 29e959fdb932..63793f9664c7 100644
> --- a/drivers/staging/iio/meter/ade7854-i2c.c
> +++ b/drivers/staging/iio/meter/ade7854-i2c.c
> @@ -65,9 +65,10 @@ static int ade7854_i2c_write_reg(struct device *dev,
>  	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,