Re: [PATCH v2 6/8] iio: adc: stm32-dfsdm: add support for scan mode

Jonathan Cameron
2019-03-24T16:47:07Z

On Thu, 21 Mar 2019 17:47:27 +0100
Fabrice Gasnier <fabrice.gasnier@st.com> wrote:

> In order to support multiple channels in buffer mode, add support for scan
> mode. This is precursor patch to ease support of triggered buffer mode.
> Currently, only audio uses buffer mode: Regular continuous conversions
> with a single channel (per filter).
> DFSDM hardware supports scan mode (only) with injected conversions.
> Conversions can be launched by software (JSWSTART), trigger or
> synchronously with filter 0 (e.g. JSYNC). Continuous conversion mode isn't
> available for injected.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Applied,

Thanks,

Jonathan

> ---
> drivers/iio/adc/stm32-dfsdm-adc.c | 182 +++++++++++++++++++++++++++++---------
> 1 file changed, 142 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
> index b491424..4ead6bf 100644
> --- a/drivers/iio/adc/stm32-dfsdm-adc.c
> +++ b/drivers/iio/adc/stm32-dfsdm-adc.c
> @@ -40,7 +40,8 @@
>
> /* Filter configuration */
> #define DFSDM_CR1_CFG_MASK (DFSDM_CR1_RCH_MASK | DFSDM_CR1_RCONT_MASK | \
> - DFSDM_CR1_RSYNC_MASK)
> + DFSDM_CR1_RSYNC_MASK | DFSDM_CR1_JSYNC_MASK | \
> + DFSDM_CR1_JSCAN_MASK)
>
> enum sd_converter_type {
> DFSDM_AUDIO,
> @@ -58,6 +59,8 @@ struct stm32_dfsdm_adc {
> struct stm32_dfsdm *dfsdm;
> const struct stm32_dfsdm_dev_data *dev_data;
> unsigned int fl_id;
> + unsigned int nconv;
> + unsigned long smask;
>
> /* ADC specific */
> unsigned int oversamp;
> @@ -204,19 +207,39 @@ static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl,
> return 0;
> }
>
> -static int stm32_dfsdm_start_channel(struct stm32_dfsdm *dfsdm,
> - unsigned int ch_id)
> +static int stm32_dfsdm_start_channel(struct stm32_dfsdm_adc *adc)
> {
> - return regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
> - DFSDM_CHCFGR1_CHEN_MASK,
> - DFSDM_CHCFGR1_CHEN(1));
> + struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> + struct regmap *regmap = adc->dfsdm->regmap;
> + const struct iio_chan_spec *chan;
> + unsigned int bit;
> + int ret;
> +
> + for_each_set_bit(bit, &adc->smask, sizeof(adc->smask) * BITS_PER_BYTE) {
> + chan = indio_dev->channels + bit;
> + ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(chan->channel),
> + DFSDM_CHCFGR1_CHEN_MASK,
> + DFSDM_CHCFGR1_CHEN(1));
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> }
>
> -static void stm32_dfsdm_stop_channel(struct stm32_dfsdm *dfsdm,
> - unsigned int ch_id)
> +static void stm32_dfsdm_stop_channel(struct stm32_dfsdm_adc *adc)
> {
> - regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
> - DFSDM_CHCFGR1_CHEN_MASK, DFSDM_CHCFGR1_CHEN(0));
> + struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> + struct regmap *regmap = adc->dfsdm->regmap;
> + const struct iio_chan_spec *chan;
> + unsigned int bit;
> +
> + for_each_set_bit(bit, &adc->smask, sizeof(adc->smask) * BITS_PER_BYTE) {
> + chan = indio_dev->channels + bit;
> + regmap_update_bits(regmap, DFSDM_CHCFGR1(chan->channel),
> + DFSDM_CHCFGR1_CHEN_MASK,
> + DFSDM_CHCFGR1_CHEN(0));
> + }
> }
>
> static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm,
> @@ -241,9 +264,10 @@ static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm,
> DFSDM_CHCFGR1_CHINSEL(ch->alt_si));
> }
>
> -static int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm,
> +static int stm32_dfsdm_start_filter(struct stm32_dfsdm_adc *adc,
> unsigned int fl_id)
> {
> + struct stm32_dfsdm *dfsdm = adc->dfsdm;
> int ret;
>
> /* Enable filter */
> @@ -252,7 +276,11 @@ static int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm,
> if (ret < 0)
> return ret;
>
> - /* Start conversion */
> + /* Nothing more to do for injected (scan mode/triggered) conversions */
> + if (adc->nconv > 1)
> + return 0;
> +
> + /* Software start (single or continuous) regular conversion */
> return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
> DFSDM_CR1_RSWSTART_MASK,
> DFSDM_CR1_RSWSTART(1));
> @@ -267,12 +295,14 @@ static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm,
> }
>
> static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc,
> - unsigned int fl_id, unsigned int ch_id)
> + unsigned int fl_id)
> {
> struct iio_dev *indio_dev = iio_priv_to_dev(adc);
> struct regmap *regmap = adc->dfsdm->regmap;
> struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
> u32 cr1;
> + const struct iio_chan_spec *chan;
> + unsigned int bit, jchg = 0;
> int ret;
>
> /* Average integrator oversampling */
> @@ -292,14 +322,59 @@ static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc,
> if (ret)
> return ret;
>
> - /* No scan mode supported for the moment */
> - cr1 = DFSDM_CR1_RCH(ch_id);
> + /*
> + * DFSDM modes configuration W.R.T audio/iio type modes
> + * ----------------------------------------------------------------
> + * Modes | regular | regular | injected | injected |
> + * | | continuous | | + scan |
> + * --------------|---------|--------------|----------|------------|
> + * single conv | x | | | |
> + * (1 chan) | | | | |
> + * --------------|---------|--------------|----------|------------|
> + * 1 Audio chan | | sample freq | | |
> + * | | or sync_mode | | |
> + * --------------|---------|--------------|----------|------------|
> + * 1 IIO chan | | sample freq | trigger | |
> + * | | or sync_mode | | |
> + * --------------|---------|--------------|----------|------------|
> + * 2+ IIO chans | | | | trigger or |
> + * | | | | sync_mode |
> + * ----------------------------------------------------------------
> + */
> + if (adc->nconv == 1) {
> + bit = __ffs(adc->smask);
> + chan = indio_dev->channels + bit;
>
> - /* Continuous conversions triggered by SPI clock in buffer mode */
> - if (indio_dev->currentmode & INDIO_BUFFER_SOFTWARE)
> - cr1 |= DFSDM_CR1_RCONT(1);
> + /* Use regular conversion for single channel without trigger */
> + cr1 = DFSDM_CR1_RCH(chan->channel);
>
> - cr1 |= DFSDM_CR1_RSYNC(fl->sync_mode);
> + /* Continuous conversions triggered by SPI clk in buffer mode */
> + if (indio_dev->currentmode & INDIO_BUFFER_SOFTWARE)
> + cr1 |= DFSDM_CR1_RCONT(1);
> +
> + cr1 |= DFSDM_CR1_RSYNC(fl->sync_mode);
> + } else {
> + /* Use injected conversion for multiple channels */
> + for_each_set_bit(bit, &adc->smask,
> + sizeof(adc->smask) * BITS_PER_BYTE) {
> + chan = indio_dev->channels + bit;
> + jchg |= BIT(chan->channel);
> + }
> + ret = regmap_write(regmap, DFSDM_JCHGR(fl_id), jchg);
> + if (ret < 0)
> + return ret;
> +
> + /* Use scan mode for multiple channels */
> + cr1 = DFSDM_CR1_JSCAN(1);
> +
> + /*
> + * Continuous conversions not supported in injected mode:
> + * - use conversions in sync with filter 0
> + */
> + if (!fl->sync_mode)
> + return -EINVAL;
> + cr1 |= DFSDM_CR1_JSYNC(fl->sync_mode);
> + }
>
> return regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_CFG_MASK,
> cr1);
> @@ -428,21 +503,20 @@ 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,
> - const struct iio_chan_spec *chan)
> +static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc)
> {
> struct regmap *regmap = adc->dfsdm->regmap;
> int ret;
>
> - ret = stm32_dfsdm_start_channel(adc->dfsdm, chan->channel);
> + ret = stm32_dfsdm_start_channel(adc);
> if (ret < 0)
> return ret;
>
> - ret = stm32_dfsdm_filter_configure(adc, adc->fl_id, chan->channel);
> + ret = stm32_dfsdm_filter_configure(adc, adc->fl_id);
> if (ret < 0)
> goto stop_channels;
>
> - ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
> + ret = stm32_dfsdm_start_filter(adc, adc->fl_id);
> if (ret < 0)
> goto filter_unconfigure;
>
> @@ -452,13 +526,12 @@ static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc,
> regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
> DFSDM_CR1_CFG_MASK, 0);
> stop_channels:
> - stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel);
> + stm32_dfsdm_stop_channel(adc);
>
> return ret;
> }
>
> -static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc,
> - const struct iio_chan_spec *chan)
> +static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
> {
> struct regmap *regmap = adc->dfsdm->regmap;
>
> @@ -467,7 +540,7 @@ static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc,
> regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
> DFSDM_CR1_CFG_MASK, 0);
>
> - stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel);
> + stm32_dfsdm_stop_channel(adc);
> }
>
> static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
> @@ -557,8 +630,7 @@ static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
> {
> struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
> struct dma_slave_config config = {
> - .src_addr = (dma_addr_t)adc->dfsdm->phys_base +
> - DFSDM_RDATAR(adc->fl_id),
> + .src_addr = (dma_addr_t)adc->dfsdm->phys_base,
> .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
> };
> struct dma_async_tx_descriptor *desc;
> @@ -571,6 +643,10 @@ static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
> dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
> adc->buf_sz, adc->buf_sz / 2);
>
> + if (adc->nconv == 1)
> + config.src_addr += DFSDM_RDATAR(adc->fl_id);
> + else
> + config.src_addr += DFSDM_JDATAR(adc->fl_id);
> ret = dmaengine_slave_config(adc->dma_chan, &config);
> if (ret)
> return ret;
> @@ -595,9 +671,20 @@ static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
> /* Issue pending DMA requests */
> dma_async_issue_pending(adc->dma_chan);
>
> - /* Enable DMA transfer*/
> - ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR1(adc->fl_id),
> - DFSDM_CR1_RDMAEN_MASK, DFSDM_CR1_RDMAEN_MASK);
> + if (adc->nconv == 1) {
> + /* Enable regular DMA transfer*/
> + ret = regmap_update_bits(adc->dfsdm->regmap,
> + DFSDM_CR1(adc->fl_id),
> + DFSDM_CR1_RDMAEN_MASK,
> + DFSDM_CR1_RDMAEN_MASK);
> + } else {
> + /* Enable injected DMA transfer*/
> + ret = regmap_update_bits(adc->dfsdm->regmap,
> + DFSDM_CR1(adc->fl_id),
> + DFSDM_CR1_JDMAEN_MASK,
> + DFSDM_CR1_JDMAEN_MASK);
> + }
> +
> if (ret < 0)
> goto err_stop_dma;
>
> @@ -617,14 +704,26 @@ static void stm32_dfsdm_adc_dma_stop(struct iio_dev *indio_dev)
> return;
>
> regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR1(adc->fl_id),
> - DFSDM_CR1_RDMAEN_MASK, 0);
> + DFSDM_CR1_RDMAEN_MASK | DFSDM_CR1_JDMAEN_MASK, 0);
> dmaengine_terminate_all(adc->dma_chan);
> }
>
> +static int stm32_dfsdm_update_scan_mode(struct iio_dev *indio_dev,
> + const unsigned long *scan_mask)
> +{
> + struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
> +
> + adc->nconv = bitmap_weight(scan_mask, indio_dev->masklength);
> + adc->smask = *scan_mask;
> +
> + dev_dbg(&indio_dev->dev, "nconv=%d mask=%lx\n", adc->nconv, *scan_mask);
> +
> + return 0;
> +}
> +
> 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 */
> @@ -646,7 +745,7 @@ static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
> goto stop_dfsdm;
> }
>
> - ret = stm32_dfsdm_start_conv(adc, chan);
> + ret = stm32_dfsdm_start_conv(adc);
> if (ret) {
> dev_err(&indio_dev->dev, "Can't start conversion\n");
> goto err_stop_dma;
> @@ -668,9 +767,8 @@ 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];
>
> - stm32_dfsdm_stop_conv(adc, chan);
> + stm32_dfsdm_stop_conv(adc);
>
> stm32_dfsdm_adc_dma_stop(indio_dev);
>
> @@ -756,7 +854,9 @@ static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
> if (ret < 0)
> goto stop_dfsdm;
>
> - ret = stm32_dfsdm_start_conv(adc, chan);
> + adc->nconv = 1;
> + adc->smask = BIT(chan->scan_index);
> + ret = stm32_dfsdm_start_conv(adc);
> if (ret < 0) {
> regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
> DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
> @@ -777,7 +877,7 @@ static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
> else
> ret = IIO_VAL_INT;
>
> - stm32_dfsdm_stop_conv(adc, chan);
> + stm32_dfsdm_stop_conv(adc);
>
> stop_dfsdm:
> stm32_dfsdm_stop_dfsdm(adc->dfsdm);
> @@ -882,11 +982,13 @@ static const struct iio_info stm32_dfsdm_info_audio = {
> .hwfifo_set_watermark = stm32_dfsdm_set_watermark,
> .read_raw = stm32_dfsdm_read_raw,
> .write_raw = stm32_dfsdm_write_raw,
> + .update_scan_mode = stm32_dfsdm_update_scan_mode,
> };
>
> static const struct iio_info stm32_dfsdm_info_adc = {
> .read_raw = stm32_dfsdm_read_raw,
> .write_raw = stm32_dfsdm_write_raw,
> + .update_scan_mode = stm32_dfsdm_update_scan_mode,
> };
>
> static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)