Re: [PATCH 3/3] iio: dac: add support for Microchip MCP48FEB02

On Thu, 23 Jul 2026 16:43:12 +0300
Ariana Lazar <[email protected]> wrote:

> This is the iio driver for Microchip MCP48FxBy1/2/4/8 series of
> buffered voltage output Digital-to-Analog Converters with nonvolatile or
> volatile memory and an SPI Interface.
> 
> The families support up to 8 output channels.
> 
> The devices can be 8-bit, 10-bit and 12-bit.
> 
> Signed-off-by: Ariana Lazar <[email protected]>
> ---

...

> +#include <linux/device.h>

No need to include device.h, as struct device * is an opaque
pointer.

Instead, add dev_printk.h as you're using dev_err_probe().

> +#include <linux/err.h>
> +#include <linux/export.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>

Don't include mod_devicetable.h, this header has recently been
added to spi.h, thanks to the effort of Uwe Kleine-Konig.

> +#include <linux/pm.h>
> +#include <linux/regmap.h>
> +#include <linux/spi/spi.h>
> +
> +#include "mcp47feb02.h"
> +

...

> +
> +static int mcp47feb02_spi_probe(struct spi_device *spi)
> +{
> +	const struct mcp47feb02_features *chip_features;
> +	struct device *dev = &spi->dev;
> +	struct regmap *regmap;
> +
> +	chip_features = spi_get_device_match_data(spi);
> +	if (!chip_features)
> +		return -EINVAL;

What about returning dev_err_probe() and -ENODEV instead of -EINVAL?
It's about 50-50 in the kernel but -ENODEV seems more suitable as an
error code if spi_get_device_match_data() fails.

-- 
Kind regards,
Joshua Crofts