linux-kernel - Re: [PATCH v3 3/8] staging:iio:ade7854: Rework I2C write function

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Date:   Sat, 24 Mar 2018 13:24:38 +0000
From:   Jonathan Cameron <jic23@...nel.org>
To:     Rodrigo Siqueira <rodrigosiqueiramelo@...il.com>
Cc:     John Syne <john3909@...il.com>, Hartmut Knaack <knaack.h@....de>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Peter Meerwald-Stadler <pmeerw@...erw.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-iio@...r.kernel.org, devel@...verdev.osuosl.org,
        linux-kernel@...r.kernel.org, Barry Song <21cnbao@...il.com>,
        daniel.baluta@....com
Subject: Re: [PATCH v3 3/8] staging:iio:ade7854: Rework I2C write function

On Fri, 23 Mar 2018 11:26:06 -0300
Rodrigo Siqueira <rodrigosiqueiramelo@...il.com> wrote:

> 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@...il.com>
Applied.

Thanks,

Jonathan

> ---
> Changes in v3:
>  - Remove the use of defines that not improve the readability
>  - Replace variable name "bytes" for "bits"
> 
>  drivers/staging/iio/meter/ade7854-i2c.c | 96 ++++++++++++++++-----------------
>  1 file changed, 46 insertions(+), 50 deletions(-)
> 
> diff --git a/drivers/staging/iio/meter/ade7854-i2c.c b/drivers/staging/iio/meter/ade7854-i2c.c
> index 37c957482493..c9f46d26b752 100644
> --- a/drivers/staging/iio/meter/ade7854-i2c.c
> +++ b/drivers/staging/iio/meter/ade7854-i2c.c
> @@ -15,86 +15,82 @@
>  #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,
> +				 int bits)
>  {
>  	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 (bits) {
> +	case 8:
> +		st->tx[2] = val & 0xFF;
> +		count = 3;
> +		break;
> +	case 16:
> +		st->tx[2] = (val >> 8) & 0xFF;
> +		st->tx[3] = val & 0xFF;
> +		count = 4;
> +		break;
> +	case 24:
> +		st->tx[2] = (val >> 16) & 0xFF;
> +		st->tx[3] = (val >> 8) & 0xFF;
> +		st->tx[4] = val & 0xFF;
> +		count = 5;
> +		break;
> +	case 32:
> +		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 unlock;
> +	}
> +
> +	ret = i2c_master_send(st->i2c, st->tx, count);
> +
> +unlock:
>  	mutex_unlock(&st->buf_lock);
>  
>  	return ret < 0 ? ret : 0;
>  }
>  
> +static int ade7854_i2c_write_reg_8(struct device *dev,
> +				   u16 reg_address,
> +				   u8 val)
> +{
> +	return ade7854_i2c_write_reg(dev, reg_address, val, 8);
> +}
> +
>  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);
> -
> -	return ret < 0 ? ret : 0;
> +	return ade7854_i2c_write_reg(dev, reg_address, val, 16);
>  }
>  
>  static int ade7854_i2c_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);
> -
> -	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);
> -
> -	return ret < 0 ? ret : 0;
> +	return ade7854_i2c_write_reg(dev, reg_address, val, 24);
>  }
>  
>  static int ade7854_i2c_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);
> -
> -	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);
> -
> -	return ret < 0 ? ret : 0;
> +	return ade7854_i2c_write_reg(dev, reg_address, val, 32);
>  }
>  
>  static int ade7854_i2c_read_reg_8(struct device *dev,