Re: [PATCH v2 3/5] max44000: Support controlling LED current output

From: Jonathan Cameron
Date: Sun Apr 17 2016 - 05:26:08 EST


On 11/04/16 19:52, Crestez Dan Leonard wrote:
> This is exposed as an output channel with "led" as an extend_name.
>
> Other sensors also have support for controlling an external LED. It's
> not clear that simply exposing an undecorated output channel is the
> correct approach.
Agreed that this is still unclear. Lets go with this for now, we can always
add an additional interface to control it if we come to a firm conclusion on
this in the future.

This patch looks good to me.
>
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
> ---
> drivers/iio/light/max44000.c | 53 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
> index 39853ff..662a45b 100644
> --- a/drivers/iio/light/max44000.c
> +++ b/drivers/iio/light/max44000.c
> @@ -124,6 +124,13 @@ static const struct iio_chan_spec max44000_channels[] = {
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> },
> + {
> + .type = IIO_CURRENT,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .extend_name = "led",
> + .output = 1,
> + },
> };
>
> static int max44000_read_alsval(struct max44000_data *data)
> @@ -164,6 +171,20 @@ static int max44000_write_led_current_raw(struct max44000_data *data, int val)
> MAX44000_LED_CURRENT_MASK, val);
> }
>
> +static int max44000_read_led_current_raw(struct max44000_data *data)
> +{
> + unsigned int regval;
> + int ret;
> +
> + ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, &regval);
> + if (ret < 0)
> + return ret;
> + regval &= MAX44000_LED_CURRENT_MASK;
> + if (regval >= 8)
> + regval -= 4;
> + return regval;
> +}
> +
> static int max44000_read_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan,
> int *val, int *val2, long mask)
> @@ -193,12 +214,26 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
> *val = regval;
> return IIO_VAL_INT;
>
> + case IIO_CURRENT:
> + mutex_lock(&data->lock);
> + ret = max44000_read_led_current_raw(data);
> + mutex_unlock(&data->lock);
> + if (ret < 0)
> + return ret;
> + *val = ret;
> + return IIO_VAL_INT;
> +
> default:
> return -EINVAL;
> }
>
> case IIO_CHAN_INFO_SCALE:
> switch (chan->type) {
> + case IIO_CURRENT:
> + /* Output register is in 10s of miliamps */
> + *val = 10;
> + return IIO_VAL_INT;
> +
> case IIO_LIGHT:
> *val = 1;
> *val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2;
> @@ -213,9 +248,27 @@ static int max44000_read_raw(struct iio_dev *indio_dev,
> }
> }
>
> +static int max44000_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + struct max44000_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {
> + mutex_lock(&data->lock);
> + ret = max44000_write_led_current_raw(data, val);
> + mutex_unlock(&data->lock);
> + return ret;
> + }
> +
> + return -EINVAL;
> +}
> +
> static const struct iio_info max44000_info = {
> .driver_module = THIS_MODULE,
> .read_raw = max44000_read_raw,
> + .write_raw = max44000_write_raw,
> };
>
> static bool max44000_readable_reg(struct device *dev, unsigned int reg)
>