ASoC: stm32: dfsdm: add actual resolution trace

Add a trace to report actual resolution of audio samples.

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Link: https://lore.kernel.org/r/20201007153459.22155-3-olivier.moysan@st.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: omn29

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;
 };