Re: [PATCH 1/3] iio: chemical: sgp40: Implement get_serial_number-command

[Andy Shevchenko]

On Fri, Sep 18, 2026 at 04:40:17PM +0300, Jaakko Koivisto wrote:
> -Retrieve the chip serial number.
> -Present the serial number to userspace as device attribute.
> -Rename the tg_measure -struct now that is is used for multiple
> commands.

...

> +	ret = i2c_master_send(client, (char*)&get_sn, sizeof(get_sn.command));
> +	if (ret != sizeof(get_sn.command)) {
> +		dev_err(data->dev, "i2c_master_send ret: %d, expected %zu", ret, sizeof(get_sn.command));
> +		return -EIO;
> +	}
> +	msleep(1);

Explain this sleep.

> +	ret = i2c_master_recv(client, (char*)&res, sizeof(res));
> +	if (ret < 0)
> +		return ret;
> +	if (ret != sizeof(res)) {
> +		dev_err(data->dev, "i2c_master_recv ret: %d, expected: %zu", ret, sizeof(res));
> +		return -EIO;
> +	}
> +
> +	if (crc8(sgp40_crc8_table, (u8*)&res.A, 2, SGP40_CRC8_INIT) != res.A_crc ||
> +	    crc8(sgp40_crc8_table, (u8*)&res.B, 2, SGP40_CRC8_INIT) != res.B_crc ||
> +	    crc8(sgp40_crc8_table, (u8*)&res.C, 2, SGP40_CRC8_INIT) != res.C_crc)
> +	{
> +		dev_warn(data->dev, "CRC error in get_serial_number");
> +	}
> +
> +	data->serial_number = 0LL | ((u64)be16_to_cpu(res.A) << 32) | ((u64)be16_to_cpu(res.B) << 16) | (u64)be16_to_cpu(res.C);

0LL ?!

> +	dev_dbg(data->dev, "serial number: %llu", data->serial_number);

Why?!

...

> -	struct sgp40_tg_measure tg = {.command = {0x26, 0x0F}};
> +	struct sgp40_command tg = {.command = {0x26, 0x0F}};

While at it, add more spaces.

...

> +}
> +

Unneeded blank line.

> +static IIO_DEVICE_ATTR_RO(serial_number, 0);
> +
> +static struct attribute *sgp40_attributes[] = {
> +	&iio_dev_attr_serial_number.dev_attr.attr,
> +	NULL
> +};
> +
> +static struct attribute_group sgp40_attribute_group = {
> +	.attrs = sgp40_attributes,
> +};
> +
> +

Single blank line is enough and we have ATTRIBUTE_GROUPS().

-- 
With Best Regards,
Andy Shevchenko