Merge series "ASoC: stm32: dfsdm: change rate limits" from Olivier Moysan <[email protected]>:

Widening of the supported rate range in the STM32 DFSDM driver.
The rates were previously limited to 8kHz, 16kHz and 32kHz.
Allow rate capture in the whole range 8kHz-48kHz as there is no hardware
limitation to support it.
Actual sample resolution is dependent on audio rate and DFSDM configuration.
Add a trace to allow simple check of sample resolution.

Olivier Moysan (2):
  ASoC: stm32: dfsdm: change rate limits
  ASoC: stm32: dfsdm: add actual resolution trace

 drivers/iio/adc/stm32-dfsdm-adc.c | 4 ++++
 drivers/iio/adc/stm32-dfsdm.h     | 2 ++
 sound/soc/stm/stm32_adfsdm.c      | 8 +++-----
 3 files changed, 9 insertions(+), 5 deletions(-)

--
2.17.1

Author: broonie

drivers/iio/adc/stm32-dfsdm-adc.c

@@ -293,6 +293,7 @@ static int stm32_dfsdm_compute_osrs(struct stm32_dfsdm_filter *fl,
 					max >>= flo->rshift;
 				}
 				flo->max = (s32)max;
+				flo->bits = bits;
 
 				pr_debug("%s: fast %d, fosr %d, iosr %d, res 0x%llx/%d bits, rshift %d, lshift %d\n",
 					 __func__, fast, flo->fosr, flo->iosr,
@@ -476,6 +477,9 @@ static int stm32_dfsdm_channels_configure(struct iio_dev *indio_dev,
 	if (!flo->res)
 		return -EINVAL;
 
+	dev_dbg(&indio_dev->dev, "Samples actual resolution: %d bits",
+		min(flo->bits, (u32)DFSDM_DATA_RES - 1));
+
 	for_each_set_bit(bit, &adc->smask,
 			 sizeof(adc->smask) * BITS_PER_BYTE) {
 		chan = indio_dev->channels + bit;

drivers/iio/adc/stm32-dfsdm.h

@@ -249,6 +249,7 @@ enum stm32_dfsdm_sinc_order {
  * @rshift: output sample right shift (hardware shift)
  * @lshift: output sample left shift (software shift)
  * @res: output sample resolution
+ * @bits: output sample resolution in bits
  * @max: output sample maximum positive value
  */
 struct stm32_dfsdm_filter_osr {
@@ -257,6 +258,7 @@ struct stm32_dfsdm_filter_osr {
 	unsigned int rshift;
 	unsigned int lshift;
 	u64 res;
+	u32 bits;
 	s32 max;
 };
 

sound/soc/stm/stm32_adfsdm.c

@@ -47,9 +47,6 @@ static const struct snd_pcm_hardware stm32_adfsdm_pcm_hw = {
 		SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_PAUSE,
 	.formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S32_LE,
 
-	.rate_min = 8000,
-	.rate_max = 32000,
-
 	.channels_min = 1,
 	.channels_max = 1,
 
@@ -143,8 +140,9 @@ static const struct snd_soc_dai_driver stm32_adfsdm_dai = {
 		    .channels_max = 1,
 		    .formats = SNDRV_PCM_FMTBIT_S16_LE |
 			       SNDRV_PCM_FMTBIT_S32_LE,
-		    .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
-			      SNDRV_PCM_RATE_32000),
+		    .rates = SNDRV_PCM_RATE_CONTINUOUS,
+		    .rate_min = 8000,
+		    .rate_max = 48000,
 		    },
 	.ops = &stm32_adfsdm_dai_ops,
 };