Re: [PATCH 4/7] iio: adc: stm32-dfsdm: fix multiple channel initialization

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 23 Feb 2018 13:50:58 +0100
Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> When several channels are registered (e.g. via st,adc-channels property):
> - channels array is wrongly filled in. Only 1st element in array is being
>   initialized with last registered channel.
>   Fix it by passing reference to relevant channel (e.g. array[index]).
> - only last initialized channel can work properly (e.g. unique 'ch_id'
>   is used). Converting any other channel result in conversion timeout.
>   Fix it by getting rid of 'ch_id', use chan->channel instead.
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Applied to the fixes-togreg branch of iio.git.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/stm32-dfsdm-adc.c | 39 +++++++++++++++++++++------------------
>  1 file changed, 21 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
> index 0eff811..01422d1 100644
> --- a/drivers/iio/adc/stm32-dfsdm-adc.c
> +++ b/drivers/iio/adc/stm32-dfsdm-adc.c
> @@ -54,7 +54,6 @@ struct stm32_dfsdm_adc {
>  	struct stm32_dfsdm *dfsdm;
>  	const struct stm32_dfsdm_dev_data *dev_data;
>  	unsigned int fl_id;
> -	unsigned int ch_id;
>  
>  	/* ADC specific */
>  	unsigned int oversamp;
> @@ -384,7 +383,7 @@ static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
>  {
>  	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
>  	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
> -	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
> +	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel];
>  	unsigned int sample_freq = adc->sample_freq;
>  	unsigned int spi_freq;
>  	int ret;
> @@ -419,18 +418,20 @@ static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
>  	return len;
>  }
>  
> -static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
> +static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc,
> +				  const struct iio_chan_spec *chan,
> +				  bool dma)
>  {
>  	struct regmap *regmap = adc->dfsdm->regmap;
>  	int ret;
>  	unsigned int dma_en = 0, cont_en = 0;
>  
> -	ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id);
> +	ret = stm32_dfsdm_start_channel(adc->dfsdm, chan->channel);
>  	if (ret < 0)
>  		return ret;
>  
>  	ret = stm32_dfsdm_filter_configure(adc->dfsdm, adc->fl_id,
> -					   adc->ch_id);
> +					   chan->channel);
>  	if (ret < 0)
>  		goto stop_channels;
>  
> @@ -464,12 +465,13 @@ static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
>  
>  	regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
>  			   DFSDM_CR1_RCONT_MASK, 0);
> -	stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
> +	stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel);
>  
>  	return ret;
>  }
>  
> -static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
> +static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc,
> +				  const struct iio_chan_spec *chan)
>  {
>  	struct regmap *regmap = adc->dfsdm->regmap;
>  
> @@ -482,7 +484,7 @@ static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
>  	regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
>  			   DFSDM_CR1_RCONT_MASK, 0);
>  
> -	stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
> +	stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel);
>  }
>  
>  static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
> @@ -609,6 +611,7 @@ static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
>  static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
>  {
>  	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
> +	const struct iio_chan_spec *chan = &indio_dev->channels[0];
>  	int ret;
>  
>  	/* Reset adc buffer index */
> @@ -618,7 +621,7 @@ static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
>  	if (ret < 0)
>  		return ret;
>  
> -	ret = stm32_dfsdm_start_conv(adc, true);
> +	ret = stm32_dfsdm_start_conv(adc, chan, true);
>  	if (ret) {
>  		dev_err(&indio_dev->dev, "Can't start conversion\n");
>  		goto stop_dfsdm;
> @@ -635,7 +638,7 @@ static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
>  	return 0;
>  
>  err_stop_conv:
> -	stm32_dfsdm_stop_conv(adc);
> +	stm32_dfsdm_stop_conv(adc, chan);
>  stop_dfsdm:
>  	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
>  
> @@ -645,11 +648,12 @@ static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
>  static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
>  {
>  	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
> +	const struct iio_chan_spec *chan = &indio_dev->channels[0];
>  
>  	if (adc->dma_chan)
>  		dmaengine_terminate_all(adc->dma_chan);
>  
> -	stm32_dfsdm_stop_conv(adc);
> +	stm32_dfsdm_stop_conv(adc, chan);
>  
>  	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
>  
> @@ -730,7 +734,7 @@ static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
>  	if (ret < 0)
>  		goto stop_dfsdm;
>  
> -	ret = stm32_dfsdm_start_conv(adc, false);
> +	ret = stm32_dfsdm_start_conv(adc, chan, false);
>  	if (ret < 0) {
>  		regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
>  				   DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
> @@ -751,7 +755,7 @@ static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
>  	else
>  		ret = IIO_VAL_INT;
>  
> -	stm32_dfsdm_stop_conv(adc);
> +	stm32_dfsdm_stop_conv(adc, chan);
>  
>  stop_dfsdm:
>  	stm32_dfsdm_stop_dfsdm(adc->dfsdm);
> @@ -765,7 +769,7 @@ static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
>  {
>  	struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
>  	struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
> -	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
> +	struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel];
>  	unsigned int spi_freq = adc->spi_freq;
>  	int ret = -EINVAL;
>  
> @@ -972,7 +976,6 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
>  	}
>  	ch->scan_type.realbits = 24;
>  	ch->scan_type.storagebits = 32;
> -	adc->ch_id = ch->channel;
>  
>  	return stm32_dfsdm_chan_configure(adc->dfsdm,
>  					  &adc->dfsdm->ch_list[ch->channel]);
> @@ -1001,7 +1004,7 @@ static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev)
>  	}
>  	ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ);
>  
> -	d_ch = &adc->dfsdm->ch_list[adc->ch_id];
> +	d_ch = &adc->dfsdm->ch_list[ch->channel];
>  	if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
>  		adc->spi_freq = adc->dfsdm->spi_master_freq;
>  
> @@ -1042,8 +1045,8 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
>  		return -ENOMEM;
>  
>  	for (chan_idx = 0; chan_idx < num_ch; chan_idx++) {
> -		ch->scan_index = chan_idx;
> -		ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
> +		ch[chan_idx].scan_index = chan_idx;
> +		ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &ch[chan_idx]);
>  		if (ret < 0) {
>  			dev_err(&indio_dev->dev, "Channels init failed\n");
>  			return ret;