[RFC PATCH 3/3] ASoC: soc-pcm: apply BE HW constraint rules

[Codrin Ciubotariu <codrin.ciubotariu@microchip.com>]

Apply the HW constraint rules added by the BE DAIs. The constraint rules
are applied after the fixup is called for the HW parameters. This way, if
the HW parameters do not correspond with the HW capabilities, the
constraint rules will return an error. The mask and the interval
constraints are the same as the ones used for FE. The DAI link
dpcm_merged_* flags are used to check if the FE and BE must share the same
HW parameters.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
---
 include/sound/pcm.h     |  2 ++
 sound/core/pcm_native.c | 17 +++++++++++++----
 sound/soc/soc-pcm.c     | 30 ++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 198d37d04d78..b56a4435439a 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -987,6 +987,8 @@ int snd_pcm_hw_rule_div(struct snd_pcm_hw_params *params,
 			struct snd_pcm_hw_rule *rule);
 
 int snd_pcm_hw_refine(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params);
+int constrain_params_by_rules(struct snd_pcm_substream *substream,
+			      struct snd_pcm_hw_params *params);
 
 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
 				 u_int64_t mask);
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index d6f14162bce5..2ff6e182c7f5 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -22,6 +22,7 @@
 #include <sound/pcm_params.h>
 #include <sound/timer.h>
 #include <sound/minors.h>
+#include <sound/soc.h>
 #include <linux/uio.h>
 #include <linux/delay.h>
 
@@ -326,11 +327,10 @@ static int constrain_interval_params(struct snd_pcm_substream *substream,
 	return 0;
 }
 
-static int constrain_params_by_rules(struct snd_pcm_substream *substream,
-				     struct snd_pcm_hw_params *params)
+int constrain_params_by_rules(struct snd_pcm_substream *substream,
+			      struct snd_pcm_hw_params *params)
 {
-	struct snd_pcm_hw_constraints *constrs =
-					&substream->runtime->hw_constraints;
+	struct snd_pcm_hw_constraints *constrs;
 	unsigned int k;
 	unsigned int *rstamps;
 	unsigned int vstamps[SNDRV_PCM_HW_PARAM_LAST_INTERVAL + 1];
@@ -342,6 +342,14 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream,
 	bool again;
 	int changed, err = 0;
 
+	if (substream->pcm->internal) {
+		struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+
+		constrs = &rtd->dpcm[substream->stream].hw_constraints;
+	} else {
+		constrs = &substream->runtime->hw_constraints;
+	}
+
 	/*
 	 * Each application of rule has own sequence number.
 	 *
@@ -446,6 +454,7 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream,
 	kfree(rstamps);
 	return err;
 }
+EXPORT_SYMBOL(constrain_params_by_rules);
 
 static int fixup_unreferenced_params(struct snd_pcm_substream *substream,
 				     struct snd_pcm_hw_params *params)
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index dae246918e0d..5bd71d48c0de 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -1934,11 +1934,25 @@ int dpcm_be_dai_hw_params(struct snd_soc_pcm_runtime *fe, int stream)
 		memcpy(&dpcm->hw_params, &fe->dpcm[stream].hw_params,
 				sizeof(struct snd_pcm_hw_params));
 
+		/* copy FE mask and interval constraints */
+		memcpy(&be->dpcm[stream].hw_constraints.masks,
+		       &be_substream->runtime->hw_constraints.masks,
+		       sizeof(be_substream->runtime->hw_constraints.masks));
+		memcpy(&be->dpcm[stream].hw_constraints.intervals,
+		       &be_substream->runtime->hw_constraints.intervals,
+		       sizeof(be_substream->runtime->hw_constraints.intervals));
+
 		/* perform any hw_params fixups */
 		ret = snd_soc_link_be_hw_params_fixup(be, &dpcm->hw_params);
 		if (ret < 0)
 			goto unwind;
 
+		/* apply constrain rules */
+		dpcm->hw_params.rmask = ~0U;
+		ret = constrain_params_by_rules(be_substream, &dpcm->hw_params);
+		if (ret < 0)
+			goto unwind;
+
 		/* copy the fixed-up hw params for BE dai */
 		memcpy(&be->dpcm[stream].hw_params, &dpcm->hw_params,
 		       sizeof(struct snd_pcm_hw_params));
@@ -2002,6 +2016,22 @@ static int dpcm_fe_dai_hw_params(struct snd_pcm_substream *substream,
 
 	memcpy(&fe->dpcm[stream].hw_params, params,
 			sizeof(struct snd_pcm_hw_params));
+	if (!fe->dai_link->dpcm_merged_format) {
+		snd_mask_any(hw_param_mask(&fe->dpcm[stream].hw_params,
+					   SNDRV_PCM_HW_PARAM_FORMAT));
+		snd_interval_any(hw_param_interval(&fe->dpcm[stream].hw_params,
+						   SNDRV_PCM_HW_PARAM_SAMPLE_BITS));
+		snd_interval_any(hw_param_interval(&fe->dpcm[stream].hw_params,
+						   SNDRV_PCM_HW_PARAM_FRAME_BITS));
+	}
+	if (!fe->dai_link->dpcm_merged_chan) {
+		snd_interval_any(hw_param_interval(&fe->dpcm[stream].hw_params,
+						   SNDRV_PCM_HW_PARAM_CHANNELS));
+	}
+	if (!fe->dai_link->dpcm_merged_rate) {
+		snd_interval_any(hw_param_interval(&fe->dpcm[stream].hw_params,
+						   SNDRV_PCM_HW_PARAM_RATE));
+	}
 	ret = dpcm_be_dai_hw_params(fe, stream);
 	if (ret < 0)
 		goto out;
-- 
2.27.0