On Sat, 25 Nov 2023 12:56:57 +0100
Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx> wrote:
> The Vishay VEMl6075 is a low power, 16-bit resolution UVA and UVB
> light sensor with I2C interface and noise compensation (visible and
> infrarred).
>
> Every UV channel generates an output signal measured in counts per
> integration period, where the integration time is configurable.
>
> This driver adds support for both UV channels and the ultraviolet
> index (UVI) inferred from them according to the device application note
> with open-air (no teflon) coefficients.
>
> Signed-off-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>
Hi Javier,
A few more minor things. Looks good in general.
Jonathan
> diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
> new file mode 100644
> index 000000000000..a33488884076
> --- /dev/null
> +++ b/drivers/iio/light/veml6075.c
> @@ -0,0 +1,486 @@
...
> +struct veml6075_data {
> + struct i2c_client *client;
> + struct regmap *regmap;
> + struct mutex lock; /* integration time/measurement trigger lock */
Could perhaps be clearer. Maybe something like
/* Prevent integration time changing during a measurement */
> +};
> +
> +static int veml6075_shutdown(struct veml6075_data *data)
Only used in one place. Maybe just do the regmap bit directly there?
> +{
> + return regmap_update_bits(data->regmap, VEML6075_CMD_CONF,
> + VEML6075_CONF_SD, VEML6075_CONF_SD);
> +}
> +
> +static int veml6075_uva_comp(int raw_uva, int comp1, int comp2)
> +{
> + int comp1a_c, comp2a_c, uva_comp;
> +
> + comp1a_c = (comp1 * VEML6075_A_COEF) / 1000U;
> + comp2a_c = (comp2 * VEML6075_B_COEF) / 1000U;
> + uva_comp = raw_uva - comp1a_c - comp2a_c;
> +
> + return clamp_val(uva_comp, 0, U16_MAX);
> +}
> +
> +static int veml6075_uvb_comp(int raw_uvb, int comp1, int comp2)
> +{
> + int comp1b_c, comp2b_c, uvb_comp;
> +
> + comp1b_c = (comp1 * VEML6075_C_COEF) / 1000U;
Any of units.h appropriate here? I'm not sure if the / 1000U is a units
thing or not.
> + comp2b_c = (comp2 * VEML6075_D_COEF) / 1000U;
> + uvb_comp = raw_uvb - comp1b_c - comp2b_c;
> +
> + return clamp_val(uvb_comp, 0, U16_MAX);
> +}
> +
> +static int veml6075_read_uvi(struct veml6075_data *data, int *val, int *val2)
> +{
> + int ret, c1, c2, uva, uvb, uvi_micro;
> +
> + guard(mutex)(&data->lock);
> +
> + ret = veml6075_request_measurement(data);
> + if (ret < 0)
> + return ret;
> +
> + ret = veml6075_read_comp(data, &c1, &c2);
> + if (ret < 0)
> + return ret;
> +
> + ret = regmap_read(data->regmap, VEML6075_CMD_UVA, &uva);
> + if (ret < 0)
> + return ret;
> +
> + ret = regmap_read(data->regmap, VEML6075_CMD_UVB, &uvb);
> + if (ret < 0)
> + return ret;
> +
> + uvi_micro = veml6075_get_uvi_micro(data, veml6075_uva_comp(uva, c1, c2),
> + veml6075_uvb_comp(uvb, c1, c2));
> + if (uvi_micro < 0)
> + return uvi_micro;
> +
> + *val = uvi_micro / 1000000LL;
MICRO for divisor.
https://elixir.bootlin.com/linux/latest/source/include/linux/units.h#L18
> + *val2 = uvi_micro % 1000000LL;
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> +}
...
> +static int veml6075_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct veml6075_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + ret = veml6075_read_uv_direct(data, chan->channel, val);
> + break;
> + case IIO_CHAN_INFO_PROCESSED:
> + ret = veml6075_read_uvi(data, val, val2);
> + break;
> + case IIO_CHAN_INFO_INT_TIME:
> + ret = veml6075_read_int_time_ms(data, val);
> + break;
> + case IIO_CHAN_INFO_SCALE:
> + return veml6075_read_responsivity(chan->channel, val, val2);
> + default:
> + return -EINVAL;
> + }
> +
> + return ret;
return in remaining case statements above. No point in break unless
there is shared stuff to do after the switch.
> +}
> +
> +static int veml6075_write_int_time_ms(struct veml6075_data *data, int val)
> +{
> + int i = ARRAY_SIZE(veml6075_it_ms);
> +
> + guard(mutex)(&data->lock);
> +
> + while (i-- > 0) {
> + if (val == veml6075_it_ms[i])
> + break;
> + }
> + if (i < 0)
> + return -EINVAL;
> +
> + return regmap_update_bits(data->regmap, VEML6075_CMD_CONF,
> + VEML6075_CONF_IT,
> + FIELD_PREP(VEML6075_CONF_IT, i));
> +}
> +
> +static int veml6075_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + struct veml6075_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_INT_TIME:
> + ret = veml6075_write_int_time_ms(data, val);
return here.
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return ret;
return above and safe a few lines + local variable ret.
> +}
> +
> +static const struct iio_info veml6075_info = {
> + .read_avail = veml6075_read_avail,
> + .read_raw = veml6075_read_raw,
> + .write_raw = veml6075_write_raw,
> +};
...
> +static const struct regmap_config veml6075_regmap_config = {
> + .name = "veml6075",
> + .reg_bits = 8,
> + .val_bits = 16,
> + .max_register = VEML6075_CMD_ID,
> + .readable_reg = veml6075_readable_reg,
> + .writeable_reg = veml6075_writable_reg,
> + .val_format_endian = REGMAP_ENDIAN_LITTLE,
> +
stray blank line here that should go.
> +};
> +
> +static int veml6075_probe(struct i2c_client *client)
> +{
> + struct veml6075_data *data;
> + struct iio_dev *indio_dev;
> + struct regmap *regmap;
> + int config, ret;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + regmap = devm_regmap_init_i2c(client, &veml6075_regmap_config);
> + if (IS_ERR(regmap))
> + return PTR_ERR(regmap);
> +
> + data = iio_priv(indio_dev);
> + i2c_set_clientdata(client, indio_dev);
why? Doesn't look like you get it back anywhere in the driver.
> + data->client = client;
> + data->regmap = regmap;
> +
> + mutex_init(&data->lock);
> +
> + indio_dev->name = "veml6075";
> + indio_dev->info = &veml6075_info;
> + indio_dev->channels = veml6075_channels;
> + indio_dev->num_channels = ARRAY_SIZE(veml6075_channels);
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + ret = devm_regulator_get_enable(&client->dev, "vdd");
> + if (ret < 0 && ret != -ENODEV)
I'm lost here. devm_regulator_get_enable() shouldn't return -ENODEV
unless you have specified that an incomplete set of regs are provided.
If you've specified that you should provide a fixed reg.
https://elixir.bootlin.com/linux/latest/source/drivers/regulator/core.c#L2194
The paths to not having that provided shouldn't effect normal use (IIRC).
So I'd not expect special handling for -ENODEV.
That would be appropriate if you were using the optional variant, but
this regulator isn't optional (we might just not have described it!)
> + return ret;
> +
> + /* default: 100ms integration time, active force enable, shutdown */
> + config = FIELD_PREP(VEML6075_CONF_IT, VEML6075_IT_100_MS) |
> + FIELD_PREP(VEML6075_CONF_AF, VEML6075_AF_ENABLE) |
> + FIELD_PREP(VEML6075_CONF_SD, VEML6075_SD_ENABLE);
> + ret = regmap_write(data->regmap, VEML6075_CMD_CONF, config);
> + if (ret < 0)
> + return ret;
> +
> + return devm_iio_device_register(&client->dev, indio_dev);
> +}
