iio: adc: stm32-dfsdm: continuous mode depends on current mode

DFSDM regular continuous mode usage depends on current mode (not DMA):
- for single conversion, RCONT doesn't need to be set.
- for buffer mode, RCONT has to be set (e.g. INDIO_BUFFER_SOFTWARE
  used by audio currently).
This is related to filter configuration, move it to relevant routine.

This is precursor patch to ease support of triggered buffer mode.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index fcd4a1c00ca0574d02326602f68da118a499fca4..8690672b8539f8b3a6558f9a36b3450acf146b25 100644 (file)
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -38,6 +38,10 @@
 #define DFSDM_MAX_RES BIT(31)
 #define DFSDM_DATA_RES BIT(23)
 
+/* Filter configuration */
+#define DFSDM_CR1_CFG_MASK (DFSDM_CR1_RCH_MASK | DFSDM_CR1_RCONT_MASK | \
+                           DFSDM_CR1_RSYNC_MASK)
+
 enum sd_converter_type {
        DFSDM_AUDIO,
        DFSDM_IIO,
@@ -262,11 +266,13 @@ static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm,
                           DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0));
 }
 
-static int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm,
+static int stm32_dfsdm_filter_configure(struct stm32_dfsdm_adc *adc,
                                        unsigned int fl_id, unsigned int ch_id)
 {
-       struct regmap *regmap = dfsdm->regmap;
-       struct stm32_dfsdm_filter *fl = &dfsdm->fl_list[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;
        int ret;
 
        /* Average integrator oversampling */
@@ -287,14 +293,16 @@ static int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm,
                return ret;
 
        /* No scan mode supported for the moment */
-       ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_RCH_MASK,
-                                DFSDM_CR1_RCH(ch_id));
-       if (ret)
-               return ret;
+       cr1 = DFSDM_CR1_RCH(ch_id);
+
+       /* Continuous conversions triggered by SPI clock in buffer mode */
+       if (indio_dev->currentmode & INDIO_BUFFER_SOFTWARE)
+               cr1 |= DFSDM_CR1_RCONT(1);
 
-       return regmap_update_bits(regmap, DFSDM_CR1(fl_id),
-                                 DFSDM_CR1_RSYNC_MASK,
-                                 DFSDM_CR1_RSYNC(fl->sync_mode));
+       cr1 |= DFSDM_CR1_RSYNC(fl->sync_mode);
+
+       return regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_CFG_MASK,
+                                 cr1);
 }
 
 static int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
@@ -426,47 +434,39 @@ static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc,
 {
        struct regmap *regmap = adc->dfsdm->regmap;
        int ret;
-       unsigned int dma_en = 0, cont_en = 0;
+       unsigned int dma_en = 0;
 
        ret = stm32_dfsdm_start_channel(adc->dfsdm, chan->channel);
        if (ret < 0)
                return ret;
 
-       ret = stm32_dfsdm_filter_configure(adc->dfsdm, adc->fl_id,
-                                          chan->channel);
+       ret = stm32_dfsdm_filter_configure(adc, adc->fl_id, chan->channel);
        if (ret < 0)
                goto stop_channels;
 
        if (dma) {
                /* Enable DMA transfer*/
                dma_en =  DFSDM_CR1_RDMAEN(1);
-               /* Enable conversion triggered by SPI clock*/
-               cont_en = DFSDM_CR1_RCONT(1);
        }
        /* Enable DMA transfer*/
        ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
                                 DFSDM_CR1_RDMAEN_MASK, dma_en);
        if (ret < 0)
-               goto stop_channels;
-
-       /* Enable conversion triggered by SPI clock*/
-       ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
-                                DFSDM_CR1_RCONT_MASK, cont_en);
-       if (ret < 0)
-               goto stop_channels;
+               goto filter_unconfigure;
 
        ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
        if (ret < 0)
-               goto stop_channels;
+               goto stop_dma;
 
        return 0;
 
-stop_channels:
+stop_dma:
        regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
                           DFSDM_CR1_RDMAEN_MASK, 0);
-
+filter_unconfigure:
        regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
-                          DFSDM_CR1_RCONT_MASK, 0);
+                          DFSDM_CR1_CFG_MASK, 0);
+stop_channels:
        stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel);
 
        return ret;
@@ -484,7 +484,7 @@ static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc,
                           DFSDM_CR1_RDMAEN_MASK, 0);
 
        regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
-                          DFSDM_CR1_RCONT_MASK, 0);
+                          DFSDM_CR1_CFG_MASK, 0);
 
        stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel);
 }