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@xxxxxx>
---
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)
--
2.7.4
