Re: [PATCH v4 5/7] iio: accel: kionix-kx022a: Refactor driver and add chip_info structure

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Fri, May 26, 2023 at 04:30:46PM +0200, Mehdi Djait wrote:
> Add the chip_info structure to the driver's private data to hold all
> the device specific infos.
> Refactor the kx022a driver implementation to make it more generic and
> extensible.

...

> -	regmap = devm_regmap_init_i2c(i2c, &kx022a_regmap);
> +	chip_info = device_get_match_data(&i2c->dev);
> +	if (!chip_info) {
> +		const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
> +		chip_info = (const struct kx022a_chip_info *)id->driver_data;
> +	}

And if still no chip_info available?..

> +	regmap = devm_regmap_init_i2c(i2c, chip_info->regmap_config);
>  	if (IS_ERR(regmap))
>  		return dev_err_probe(dev, PTR_ERR(regmap),
>  				     "Failed to initialize Regmap\n");

...

> -	if (val > KX022A_FIFO_LENGTH)
> -		val = KX022A_FIFO_LENGTH;
> +	if (val > data->chip_info->fifo_length)
> +		val = data->chip_info->fifo_length;

min()/min_t() ?

...

> +	ret = regmap_noinc_read(data->regmap, data->chip_info->buf_read,
> +				&data->fifo_buffer[0], fifo_bytes);

data->fifo_buffer will suffice.


>  	if (ret)
>  		goto renable_out;

...

> +	data->fifo_buffer = kmalloc(data->chip_info->fifo_length *
> +				    KX022A_FIFO_SAMPLES_SIZE_BYTES, GFP_KERNEL);

> +

Redundant blank line.

> +	if (!data->fifo_buffer)
> +		return -ENOMEM;

...

> +struct kx022a_chip_info {
> +	const char *name;
> +	const struct regmap_config *regmap_config;
> +	const struct iio_chan_spec *channels;
> +	unsigned int num_channels;
> +	unsigned int fifo_length;
> +	u8 who;
> +	u8 id;
> +	u8 cntl;
> +	u8 cntl2;
> +	u8 odcntl;
> +	u8 buf_cntl1;
> +	u8 buf_cntl2;
> +	u8 buf_clear;
> +	u8 buf_status1;

Here is the gap since it's not a packed structure. Can we avoid it?

> +	u16 buf_smp_lvl_mask;
> +	u8 buf_read;
> +	u8 inc1;
> +	u8 inc4;
> +	u8 inc5;
> +	u8 inc6;
> +	u8 xout_l;
> +};

-- 
With Best Regards,
Andy Shevchenko