Re: [PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 23 Jul 2022 19:39:44 +0200
Angel Iglesias <ang.iglesiasg@gmail.com> wrote:

> Adds compatibility with the new generation of this sensor, the BMP380
> 
> Includes basic sensor initialization to do pressure and temp
> measurements and allows tuning oversampling settings for each channel.
> 
> The compensation algorithms are adapted from the device datasheet and
> the repository https://github.com/BoschSensortec/BMP3-Sensor-API
> 
> Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>

Hi Angel,

A comment below. Follows on from comment on previous patch rather than being a
suggestion to change anything in here (beyond what has already been raised by others!)

Jonathan

> +static int bmp380_read_calib(struct bmp280_data *data, unsigned int chip)
> +{
> +	struct bmp380_calib *calib = &data->calib.bmp380;
> +	int ret;
> +	u8 *buf;
> +
> +	buf = kmalloc(BMP380_CALIB_REG_COUNT, GFP_KERNEL);

Ah. The complexity in here explains somewhat why you did it with u8 in the previous
patch.  Probably still better to have a __be16 buffer for that one though
even though we can't do that here.

> +	if (!buf)
> +		return -ENOMEM;
> +
> +	/* Read temperature calibration values. */
> +	ret = regmap_bulk_read(data->regmap, BMP380_REG_CALIB_TEMP_START, buf,
> +			       BMP380_CALIB_REG_COUNT);
> +	if (ret < 0) {
> +		dev_err(data->dev,
> +			"failed to read temperature calibration parameters\n");
> +		kfree(buf);
> +		return ret;
> +	}
> +
> +	/* Toss the temperature calibration data into the entropy pool */
> +	add_device_randomness(buf, BMP380_CALIB_REG_COUNT);
> +
> +	/* Parse calibration data */
> +	calib->T1 = get_unaligned_le16(&buf[BMP380_T1]);
> +	calib->T2 = get_unaligned_le16(&buf[BMP380_T2]);
> +	calib->T3 = buf[BMP380_T3];
> +	calib->P1 = get_unaligned_le16(&buf[BMP380_P1]);
> +	calib->P2 = get_unaligned_le16(&buf[BMP380_P2]);
> +	calib->P3 = buf[BMP380_P3];
> +	calib->P4 = buf[BMP380_P4];
> +	calib->P5 = get_unaligned_le16(&buf[BMP380_P5]);
> +	calib->P6 = get_unaligned_le16(&buf[BMP380_P6]);
> +	calib->P7 = buf[BMP380_P7];
> +	calib->P8 = buf[BMP380_P8];
> +	calib->P9 = get_unaligned_le16(&buf[BMP380_P9]);
> +	calib->P10 = buf[BMP380_P10];
> +	calib->P11 = buf[BMP380_P11];
> +
> +	kfree(buf);
> +	return 0;
> +}
> +