Re: [PATCH v2 3/7] iio: light: rpr0521 sample_frequency read/write added

[Jonathan Cameron <jic23@kernel.org>]

On 07/04/17 13:07, Mikko Koivunen wrote:
> Added sysfs read/write sample frequency.
> 
> Signed-off-by: Mikko Koivunen <mikko.koivunen@fi.rohmeurope.com>
A few comments inline but looks basically good to me.

Odd little bit of hardware!

Jonathan
> ---
> Tested on LeMaker HiKey with AOSP7.1 kernel 4.4.
> 
> Patch v1->v2 changes:
> multiline comments fixed
> 
>  drivers/iio/light/rpr0521.c |   99 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 99 insertions(+)
> 
> diff --git a/drivers/iio/light/rpr0521.c b/drivers/iio/light/rpr0521.c
> index 30c2592..e92a8bb 100644
> --- a/drivers/iio/light/rpr0521.c
> +++ b/drivers/iio/light/rpr0521.c
> @@ -132,6 +132,30 @@ static const struct rpr0521_gain_info {
>  	},
>  };
>  
> +struct rpr0521_samp_freq {
> +	int	als_hz;
> +	int	als_uhz;
> +	int	pxs_hz;
> +	int	pxs_uhz;
> +};
> +
> +static const struct rpr0521_samp_freq rpr0521_samp_freq_i[13] = {
> +/*	{ALS, PXS} */
Hmm. You have them all listed here so that you can use the index as
the register value.    Maybe add a symbol to indicate in the comment
which ones you can actually use here...
> +	{0, 0, 0, 0},		/* 0000, 0=standby */
> +	{0, 0, 100, 0},		/* 0001 */
> +	{0, 0, 25, 0},		/* 0010 */
> +	{0, 0, 10, 0},		/* 0011 */
> +	{0, 0, 2, 500000},	/* 0100 */
> +	{10, 0, 20, 0},		/* 0101 */
> +	{10, 0, 10, 0},		/* 0110 */
> +	{10, 0, 2, 500000},	/* 0111 */
> +	{2, 500000, 20, 0},	/* 1000, measurement 100ms, sleep 300ms */
> +	{2, 500000, 10, 0},	/* 1001, measurement 100ms, sleep 300ms */
> +	{2, 500000, 0, 0},	/* 1010, high sensitivity mode */
> +	{2, 500000, 2, 500000},	/* 1011, high sensitivity mode */
> +	{20, 0, 20, 0}	/* 1100, ALS_data x 0.5, see specification P.18 */
Whilst this one is odd, I don't think your write function below will refuse
to set it...
> +};
> +
>  struct rpr0521_data {
>  	struct i2c_client *client;
>  
> @@ -152,9 +176,15 @@ struct rpr0521_data {
>  static IIO_CONST_ATTR(in_intensity_scale_available, RPR0521_ALS_SCALE_AVAIL);
>  static IIO_CONST_ATTR(in_proximity_scale_available, RPR0521_PXS_SCALE_AVAIL);
>  
> +/* Start with easy freq first, whole table of freq combinations is more
/*
 * Start...

(kernel multiline comment syntax)...
> + * complicated.
> + */
> +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("2.5 10");
20 not available?
> +
>  static struct attribute *rpr0521_attributes[] = {
>  	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
>  	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
> +	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
>  	NULL,
>  };
>  
> @@ -170,6 +200,7 @@ static const struct iio_chan_spec rpr0521_channels[] = {
>  		.channel2 = IIO_MOD_LIGHT_BOTH,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>  			BIT(IIO_CHAN_INFO_SCALE),
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
>  	},
>  	{
>  		.type = IIO_INTENSITY,
> @@ -178,12 +209,14 @@ static const struct iio_chan_spec rpr0521_channels[] = {
>  		.channel2 = IIO_MOD_LIGHT_IR,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>  			BIT(IIO_CHAN_INFO_SCALE),
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
>  	},
>  	{
>  		.type = IIO_PROXIMITY,
>  		.address = RPR0521_CHAN_PXS,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>  			BIT(IIO_CHAN_INFO_SCALE),
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
>  	}
>  };
>  
> @@ -319,6 +352,56 @@ static int rpr0521_set_gain(struct rpr0521_data *data, int chan,
>  				  idx << rpr0521_gain[chan].shift);
>  }
>  
> +static int rpr0521_read_samp_freq(struct rpr0521_data *data,
> +				enum iio_chan_type chan_type,
> +			    int *val, int *val2)
> +{
> +	int reg, ret;
> +
> +	ret = regmap_read(data->regmap, RPR0521_REG_MODE_CTRL, &reg);
> +	if (ret < 0)
> +		return ret;
I'd put a blank line here..
> +	reg &= RPR0521_MODE_MEAS_TIME_MASK;
> +	if (reg >= ARRAY_SIZE(rpr0521_samp_freq_i))
> +		return -EINVAL;
> +
> +	if (chan_type == IIO_INTENSITY) {
> +		*val = rpr0521_samp_freq_i[reg].als_hz;
> +		*val2 = rpr0521_samp_freq_i[reg].als_uhz;
> +	} else if (chan_type == IIO_PROXIMITY) {
> +		*val = rpr0521_samp_freq_i[reg].pxs_hz;
> +		*val2 = rpr0521_samp_freq_i[reg].pxs_uhz;
> +	} else {
> +		return -EINVAL;
switch might be tidier..  Also, perhaps return directly from first two
cases.
> +	}
> +	return 0;
> +}
> +
> +static int rpr0521_write_samp_freq_common(struct rpr0521_data *data,
> +				enum iio_chan_type chan_type,
> +				int val, int val2)
> +{
> +	int i;
> +
> +	/* Ignore channel
/*
 * Ignore channel
 ...
> +	 * both pxs and als are setup only to same freq because of simplicity
> +	 */
> +	for (i = 0; i < ARRAY_SIZE(rpr0521_samp_freq_i); i++)
> +		if ((val == rpr0521_samp_freq_i[i].als_hz)
> +			&& (val2 == rpr0521_samp_freq_i[i].als_uhz)
> +			&& (val == rpr0521_samp_freq_i[i].pxs_hz)
> +			&& (val2 == rpr0521_samp_freq_i[i].pxs_uhz)) {
Hmm. a lot of complexity introduced above by sort of allowing for them
to be different (which would indeed be a real pain to handle! Why not
just drop the ones you can never actually use?

> +			break;
> +		}
> +	if (i == ARRAY_SIZE(rpr0521_samp_freq_i))
> +		return -EINVAL;
> +
> +	return regmap_update_bits(data->regmap,
> +		RPR0521_REG_MODE_CTRL,
> +		RPR0521_MODE_MEAS_TIME_MASK,
> +		i);
> +}
> +
>  static int rpr0521_read_raw(struct iio_dev *indio_dev,
>  			    struct iio_chan_spec const *chan, int *val,
>  			    int *val2, long mask)
> @@ -365,8 +448,16 @@ static int rpr0521_read_raw(struct iio_dev *indio_dev,
>  		mutex_unlock(&data->lock);
>  		if (ret < 0)
>  			return ret;
> +		return IIO_VAL_INT_PLUS_MICRO;
>  
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		mutex_lock(&data->lock);
> +		ret = rpr0521_read_samp_freq(data, chan->type, val, val2);
> +		mutex_unlock(&data->lock);
> +		if (ret < 0)
> +			return ret;
>  		return IIO_VAL_INT_PLUS_MICRO;
> +
Again, I think you are messing with original white space.  Don't do
that as it just gives odd diff results like this one...
>  	default:
>  		return -EINVAL;
>  	}
> @@ -384,8 +475,16 @@ static int rpr0521_write_raw(struct iio_dev *indio_dev,
>  		mutex_lock(&data->lock);
>  		ret = rpr0521_set_gain(data, chan->address, val, val2);
>  		mutex_unlock(&data->lock);
You are removing the blank line here.. (I think anyway!). Not a change
that should be in this patch (or possibly happen at all - this one
is in the personal taste category).  If nothing else it made diff less
readable!
> +		return ret;
>  
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		mutex_lock(&data->lock);
> +		ret = rpr0521_write_samp_freq_common(data,
> +			chan->type,
> +			val, val2);
> +		mutex_unlock(&data->lock);
>  		return ret;
> +
>  	default:
>  		return -EINVAL;
>  	}
>