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SubjectRe: [PATCH v7 2/3] iio: (bma400) add driver for the BMA400
On Thu, Dec 19, 2019 at 6:27 AM Dan Robertson <dan@dlrobertson.com> wrote:
> Add a IIO driver for the Bosch BMA400 3-axes ultra-low power accelerometer.
> The driver supports reading from the acceleration and temperature
> registers. The driver also supports reading and configuring the output data
> rate, oversampling ratio, and scale.

...

> +static int bma400_set_accel_output_data_rate(struct bma400_data *data,
> + int hz, int uhz)
> +{
> + unsigned int idx;
> + unsigned int odr;
> + unsigned int val;
> + int ret;
> +
> + if (hz >= BMA400_ACC_ODR_MIN_WHOLE_HZ) {
> + if (uhz || hz % BMA400_ACC_ODR_MIN_WHOLE_HZ)
> + return -EINVAL;
> +
> + val = hz / BMA400_ACC_ODR_MIN_WHOLE_HZ;

Again, AFAICS division may be avoided in both cases (% and / above)
because of is_power_of_2() check below.
Can you revisit this?

> + if (!is_power_of_2(val))
> + return -EINVAL;
> +
> + idx = __ffs(val) + BMA400_ACC_ODR_MIN_RAW + 1;
> + } else if (hz == BMA400_ACC_ODR_MIN_HZ && uhz == 500000) {
> + idx = BMA400_ACC_ODR_MIN_RAW;
> + } else {
> + return -EINVAL;
> + }
> +
> + ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
> + if (ret)
> + return ret;
> +
> + /* preserve the range and normal mode osr */

> + odr = idx | (~BMA400_ACC_ODR_MASK & val);

Yoda style?

> +
> + ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG, odr);
> + if (ret)
> + return ret;
> +
> + bma400_output_data_rate_from_raw(idx, &data->sample_freq.hz,
> + &data->sample_freq.uhz);
> + return 0;
> +}
...

> +int bma400_accel_scale_to_raw(struct bma400_data *data, unsigned int val)
> +{
> + int scale = val / BMA400_SCALE_MIN;
> + int raw;
> +
> + if (scale == 0)
> + return -EINVAL;
> +
> + raw = __ffs(scale);
> +
> + if (val % BMA400_SCALE_MIN || !is_power_of_2(scale))
> + return -EINVAL;

Ditto.

> +
> + return raw;
> +}

...

> +out:

Make a little sense. Why not return directly?

> + return ret;

...

> + ret = bma400_init(data);
> + if (ret < 0)

May it be positive value returned?

> + return ret;

...

> +static int bma400_i2c_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct regmap *regmap;
> +
> + regmap = devm_regmap_init_i2c(client, &bma400_regmap_config);

> +

Redundant blank line.

> + if (IS_ERR(regmap)) {
> + dev_err(&client->dev, "failed to create regmap\n");
> + return PTR_ERR(regmap);
> + }
> +
> + return bma400_probe(&client->dev, regmap, id->name);
> +}

--
With Best Regards,
Andy Shevchenko

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