ASoC: rsnd: add DPCM based sampling rate convert

This patch supports DPCM based sampling rate convert on Renesas sound
driver. It assumes...
 1. SRC is implemented as FE
 2. BE dai_link supports .be_hw_params_fixup
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/core.c

@@ -203,7 +203,7 @@ u32 rsnd_get_adinr(struct rsnd_mod *mod)
 ({								\
 	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);		\
 	struct device *dev = rsnd_priv_to_dev(priv);		\
-	u32 mask = 1 << __rsnd_mod_shift_##func;			\
+	u32 mask = (1 << __rsnd_mod_shift_##func) & ~(1 << 31);	\
 	u32 call = __rsnd_mod_call_##func << __rsnd_mod_shift_##func;	\
 	int ret = 0;							\
 	if ((mod->status & mask) == call) {				\
@@ -728,6 +728,15 @@ static int rsnd_pcm_open(struct snd_pcm_substream *substream)
 static int rsnd_hw_params(struct snd_pcm_substream *substream,
 			 struct snd_pcm_hw_params *hw_params)
 {
+	struct snd_soc_dai *dai = rsnd_substream_to_dai(substream);
+	struct rsnd_dai *rdai = rsnd_dai_to_rdai(dai);
+	struct rsnd_dai_stream *io = rsnd_rdai_to_io(rdai, substream);
+	int ret;
+
+	ret = rsnd_dai_call(hw_params, io, substream, hw_params);
+	if (ret)
+		return ret;
+
 	return snd_pcm_lib_malloc_pages(substream,
 					params_buffer_bytes(hw_params));
 }

sound/soc/sh/rcar/rsnd.h

@@ -239,6 +239,9 @@ struct rsnd_mod_ops {
 		    struct rsnd_priv *priv);
 	int (*pcm_new)(struct rsnd_mod *mod,
 		       struct snd_soc_pcm_runtime *rtd);
+	int (*hw_params)(struct rsnd_mod *mod,
+			 struct snd_pcm_substream *substream,
+			 struct snd_pcm_hw_params *hw_params);
 	int (*fallback)(struct rsnd_mod *mod,
 			struct rsnd_priv *priv);
 };
@@ -262,6 +265,9 @@ struct rsnd_mod {
  * 2	0: start	1: stop
  * 3	0: pcm_new
  * 4	0: fallback
+ *
+ * 31 bit is always called (see __rsnd_mod_call)
+ * 31	0: hw_params
  */
 #define __rsnd_mod_shift_probe		0
 #define __rsnd_mod_shift_remove		0
@@ -271,6 +277,7 @@ struct rsnd_mod {
 #define __rsnd_mod_shift_stop		2
 #define __rsnd_mod_shift_pcm_new	3
 #define __rsnd_mod_shift_fallback	4
+#define __rsnd_mod_shift_hw_params	31 /* always called */
 
 #define __rsnd_mod_call_probe		0
 #define __rsnd_mod_call_remove		1
@@ -280,6 +287,7 @@ struct rsnd_mod {
 #define __rsnd_mod_call_stop		1
 #define __rsnd_mod_call_pcm_new		0
 #define __rsnd_mod_call_fallback	0
+#define __rsnd_mod_call_hw_params	0
 
 #define rsnd_mod_to_priv(mod) (rsnd_io_to_priv(rsnd_mod_to_io(mod)))
 #define rsnd_mod_to_dma(mod) (&(mod)->dma)

sound/soc/sh/rcar/src.c

@@ -22,12 +22,13 @@
 struct rsnd_src {
 	struct rsnd_src_platform_info *info; /* rcar_snd.h */
 	struct rsnd_mod mod;
+	u32 convert_rate; /* sampling rate convert */
 	int err;
 };
 
 #define RSND_SRC_NAME_SIZE 16
 
-#define rsnd_src_convert_rate(p) ((p)->info->convert_rate)
+#define rsnd_src_convert_rate(s) ((s)->convert_rate)
 #define rsnd_src_of_node(priv) \
 	of_get_child_by_name(rsnd_priv_to_dev(priv)->of_node, "rcar_sound,src")
 
@@ -288,7 +289,43 @@ static int rsnd_src_set_convert_rate(struct rsnd_mod *mod)
 	return 0;
 }
 
-static int rsnd_src_init(struct rsnd_mod *mod)
+static int rsnd_src_hw_params(struct rsnd_mod *mod,
+			      struct snd_pcm_substream *substream,
+			      struct snd_pcm_hw_params *fe_params)
+{
+	struct rsnd_src *src = rsnd_mod_to_src(mod);
+	struct snd_soc_pcm_runtime *fe = substream->private_data;
+
+	/* default value (mainly for non-DT) */
+	src->convert_rate = src->info->convert_rate;
+
+	/*
+	 * SRC assumes that it is used under DPCM if user want to use
+	 * sampling rate convert. Then, SRC should be FE.
+	 * And then, this function will be called *after* BE settings.
+	 * this means, each BE already has fixuped hw_params.
+	 * see
+	 *	dpcm_fe_dai_hw_params()
+	 *	dpcm_be_dai_hw_params()
+	 */
+	if (fe->dai_link->dynamic) {
+		int stream = substream->stream;
+		struct snd_soc_dpcm *dpcm;
+		struct snd_pcm_hw_params *be_params;
+
+		list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
+			be_params = &dpcm->hw_params;
+
+			if (params_rate(fe_params) != params_rate(be_params))
+				src->convert_rate = params_rate(be_params);
+		}
+	}
+
+	return 0;
+}
+
+static int rsnd_src_init(struct rsnd_mod *mod,
+			 struct rsnd_priv *priv)
 {
 	struct rsnd_src *src = rsnd_mod_to_src(mod);
 
@@ -317,6 +354,8 @@ static int rsnd_src_quit(struct rsnd_mod *mod,
 		dev_warn(dev, "%s[%d] under/over flow err = %d\n",
 			 rsnd_mod_name(mod), rsnd_mod_id(mod), src->err);
 
+	src->convert_rate = 0;
+
 	return 0;
 }
 
@@ -465,7 +504,7 @@ static int rsnd_src_init_gen1(struct rsnd_mod *mod,
 {
 	int ret;
 
-	ret = rsnd_src_init(mod);
+	ret = rsnd_src_init(mod, priv);
 	if (ret < 0)
 		return ret;
 
@@ -511,6 +550,7 @@ static struct rsnd_mod_ops rsnd_src_gen1_ops = {
 	.quit	= rsnd_src_quit,
 	.start	= rsnd_src_start_gen1,
 	.stop	= rsnd_src_stop_gen1,
+	.hw_params = rsnd_src_hw_params,
 };
 
 /*
@@ -736,7 +776,7 @@ static int rsnd_src_init_gen2(struct rsnd_mod *mod,
 {
 	int ret;
 
-	ret = rsnd_src_init(mod);
+	ret = rsnd_src_init(mod, priv);
 	if (ret < 0)
 		return ret;
 
@@ -780,6 +820,7 @@ static struct rsnd_mod_ops rsnd_src_gen2_ops = {
 	.quit	= rsnd_src_quit,
 	.start	= rsnd_src_start_gen2,
 	.stop	= rsnd_src_stop_gen2,
+	.hw_params = rsnd_src_hw_params,
 };
 
 struct rsnd_mod *rsnd_src_mod_get(struct rsnd_priv *priv, int id)