Re: [PATCHv5 RESEND 1/4] iio: mxs-lradc: add scale attribute to channels

[Jonathan Cameron <jic23@kernel.org>]

On 23/12/13 17:48, Alexandre Belloni wrote:
> From: Hector Palacios <hector.palacios@digi.com>
>
> Some LRADC channels have fixed pre-dividers and all have an optional
> divider by two which allows a maximum input voltage of VDDIO - 50mV.
>
> This patch
>   - adds the scaling info flag to all channels
>   - grabs the max reference voltage per channel
>     (where the fixed pre-dividers apply)
>   - allows to read the scaling attribute (computed from the Vref)
>
> Signed-off-by: Hector Palacios <hector.palacios@digi.com>.
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> Acked-by: Marek Vasut <marex@denx.de>
Applied to the togreg branch of iio.git - initially pushed out as 
testing for the autobuilders to do their magic.

Jonathan
>
> ---
>   drivers/staging/iio/adc/mxs-lradc.c | 56 +++++++++++++++++++++++++++++++++++--
>   1 file changed, 54 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
> index 5a4499c3d22a..22fef0a408db 100644
> --- a/drivers/staging/iio/adc/mxs-lradc.c
> +++ b/drivers/staging/iio/adc/mxs-lradc.c
> @@ -111,16 +111,59 @@ static const char * const mx28_lradc_irq_names[] = {
>   struct mxs_lradc_of_config {
>   	const int		irq_count;
>   	const char * const	*irq_name;
> +	const uint32_t		*vref_mv;
> +};
> +
> +#define VREF_MV_BASE 1850
> +
> +static const uint32_t mx23_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
> +	VREF_MV_BASE,		/* CH0 */
> +	VREF_MV_BASE,		/* CH1 */
> +	VREF_MV_BASE,		/* CH2 */
> +	VREF_MV_BASE,		/* CH3 */
> +	VREF_MV_BASE,		/* CH4 */
> +	VREF_MV_BASE,		/* CH5 */
> +	VREF_MV_BASE * 2,	/* CH6 VDDIO */
> +	VREF_MV_BASE * 4,	/* CH7 VBATT */
> +	VREF_MV_BASE,		/* CH8 Temp sense 0 */
> +	VREF_MV_BASE,		/* CH9 Temp sense 1 */
> +	VREF_MV_BASE,		/* CH10 */
> +	VREF_MV_BASE,		/* CH11 */
> +	VREF_MV_BASE,		/* CH12 USB_DP */
> +	VREF_MV_BASE,		/* CH13 USB_DN */
> +	VREF_MV_BASE,		/* CH14 VBG */
> +	VREF_MV_BASE * 4,	/* CH15 VDD5V */
> +};
> +
> +static const uint32_t mx28_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
> +	VREF_MV_BASE,		/* CH0 */
> +	VREF_MV_BASE,		/* CH1 */
> +	VREF_MV_BASE,		/* CH2 */
> +	VREF_MV_BASE,		/* CH3 */
> +	VREF_MV_BASE,		/* CH4 */
> +	VREF_MV_BASE,		/* CH5 */
> +	VREF_MV_BASE,		/* CH6 */
> +	VREF_MV_BASE * 4,	/* CH7 VBATT */
> +	VREF_MV_BASE,		/* CH8 Temp sense 0 */
> +	VREF_MV_BASE,		/* CH9 Temp sense 1 */
> +	VREF_MV_BASE * 2,	/* CH10 VDDIO */
> +	VREF_MV_BASE,		/* CH11 VTH */
> +	VREF_MV_BASE * 2,	/* CH12 VDDA */
> +	VREF_MV_BASE,		/* CH13 VDDD */
> +	VREF_MV_BASE,		/* CH14 VBG */
> +	VREF_MV_BASE * 4,	/* CH15 VDD5V */
>   };
>
>   static const struct mxs_lradc_of_config mxs_lradc_of_config[] = {
>   	[IMX23_LRADC] = {
>   		.irq_count	= ARRAY_SIZE(mx23_lradc_irq_names),
>   		.irq_name	= mx23_lradc_irq_names,
> +		.vref_mv	= mx23_vref_mv,
>   	},
>   	[IMX28_LRADC] = {
>   		.irq_count	= ARRAY_SIZE(mx28_lradc_irq_names),
>   		.irq_name	= mx28_lradc_irq_names,
> +		.vref_mv	= mx28_vref_mv,
>   	},
>   };
>
> @@ -155,6 +198,8 @@ struct mxs_lradc {
>
>   	struct completion	completion;
>
> +	const uint32_t		*vref_mv;
> +
>   	/*
>   	 * Touchscreen LRADC channels receives a private slot in the CTRL4
>   	 * register, the slot #7. Therefore only 7 slots instead of 8 in the
> @@ -836,6 +881,8 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>   			const struct iio_chan_spec *chan,
>   			int *val, int *val2, long m)
>   {
> +	struct mxs_lradc *lradc = iio_priv(iio_dev);
> +
>   	/* Check for invalid channel */
>   	if (chan->channel > LRADC_MAX_TOTAL_CHANS)
>   		return -EINVAL;
> @@ -857,7 +904,9 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>   			return IIO_VAL_INT_PLUS_MICRO;
>   		}
>
> -		return -EINVAL;
> +		*val = lradc->vref_mv[chan->channel];
> +		*val2 = chan->scan_type.realbits;
> +		return IIO_VAL_FRACTIONAL_LOG2;
>
>   	case IIO_CHAN_INFO_OFFSET:
>   		if (chan->type == IIO_TEMP) {
> @@ -1189,7 +1238,8 @@ static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
>   	.type = (chan_type),					\
>   	.indexed = 1,						\
>   	.scan_index = (idx),					\
> -	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
> +			      BIT(IIO_CHAN_INFO_SCALE),		\
>   	.channel = (idx),					\
>   	.scan_type = {						\
>   		.sign = 'u',					\
> @@ -1381,6 +1431,8 @@ static int mxs_lradc_probe(struct platform_device *pdev)
>   			return ret;
>   	}
>
> +	lradc->vref_mv = of_cfg->vref_mv;
> +
>   	platform_set_drvdata(pdev, iio);
>
>   	init_completion(&lradc->completion);
>