linux-kernel - Re: [PATCH v3 1/4] iio: vcnl4000: Factorize data reading and writing.

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Date:   Mon, 20 Apr 2020 11:44:25 +0200 (CEST)
From:   Peter Meerwald-Stadler <pmeerw@...erw.net>
To:     Mathieu Othacehe <m.othacehe@...il.com>
cc:     jic23@...nel.org, linux-iio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 1/4] iio: vcnl4000: Factorize data reading and
 writing.

On Mon, 20 Apr 2020, Mathieu Othacehe wrote:

> Factorize data reading in vcnl4000_measure into a vcnl4000_read_block_data
> function. Use it to provide a vcnl4000_read_data function that is able to
> read sensor data under lock. Also add a vcnl4000_write_data function.

comments below
 
> Signed-off-by: Mathieu Othacehe <m.othacehe@...il.com>
> ---
>  drivers/iio/light/vcnl4000.c | 54 +++++++++++++++++++++++++++++++++---
>  1 file changed, 50 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
> index 58e97462e803..4e87d2cf1100 100644
> --- a/drivers/iio/light/vcnl4000.c
> +++ b/drivers/iio/light/vcnl4000.c
> @@ -215,11 +215,59 @@ static int vcnl4200_init(struct vcnl4000_data *data)
>  	return 0;
>  };
>  
> +static int vcnl4000_read_block_data(struct vcnl4000_data *data, u8 data_reg,
> +				    int *val)
> +{
> +	__be16 buf;
> +	int ret;
> +
> +	ret = i2c_smbus_read_i2c_block_data(data->client,
> +		data_reg, sizeof(buf), (u8 *) &buf);
> +	if (ret < 0)
> +		goto end;
> +
> +	*val = be16_to_cpu(buf);
> +end:
> +	return ret;
> +}
> +
> +static int vcnl4000_read_data(struct vcnl4000_data *data, u8 data_reg,
> +			      int *val)
> +{
> +	int ret;
> +
> +	mutex_lock(&data->vcnl4000_lock);
> +	ret = vcnl4000_read_block_data(data, data_reg, val);
> +	mutex_unlock(&data->vcnl4000_lock);
> +
> +	return ret;
> +}
> +
> +static int vcnl4000_write_data(struct vcnl4000_data *data, u8 data_reg,
> +			       u16 val)
> +{
> +	int ret;
> +
> +	if (val > U16_MAX)
> +		return -ERANGE;
> +
> +	mutex_lock(&data->vcnl4000_lock);
> +
> +	ret = i2c_smbus_write_byte_data(data->client, data_reg, val >> 8);

why not use i2c_smbus_write_word_data()?

> +	if (ret < 0)
> +		goto end;
> +
> +	ret = i2c_smbus_write_byte_data(data->client, data_reg + 1, val);
> +end:
> +	mutex_unlock(&data->vcnl4000_lock);
> +
> +	return ret;
> +}
> +
>  static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
>  				u8 rdy_mask, u8 data_reg, int *val)
>  {
>  	int tries = 20;
> -	__be16 buf;
>  	int ret;
>  
>  	mutex_lock(&data->vcnl4000_lock);
> @@ -246,13 +294,11 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
>  		goto fail;
>  	}
>  
> -	ret = i2c_smbus_read_i2c_block_data(data->client,
> -		data_reg, sizeof(buf), (u8 *) &buf);
> +	ret = vcnl4000_read_block_data(data, data_reg, val);
>  	if (ret < 0)
>  		goto fail;
>  
>  	mutex_unlock(&data->vcnl4000_lock);
> -	*val = be16_to_cpu(buf);
>  
>  	return 0;
>  
> 

-- 

Peter Meerwald-Stadler
Mobile: +43 664 24 44 418