ASoC: rsnd: add TDM Split mode support

This patch adds TDM Split mode support. rsnd driver is assuming
audio-graph-scu-card is used for Sound Card.

This is very simple sample DT settings to use it.

	sound_card: sound {
		compatible = "audio-graph-scu-card";
		...
		convert-channels = <8>; /* TDM Split */

		dais = <&rsnd_port0     /* playback ch1/ch2 */
			&rsnd_port1     /* playback ch3/ch4 */
			&rsnd_port2     /* playback ch5/ch6 */
			&rsnd_port3     /* playback ch7/ch8 */
			>;
	};

	audio-codec {
		...
		port {
			codec_0: endpoint@1 {
				remote-endpoint = <&rsnd_ep0>;
			};
			codec_1: endpoint@2 {
				remote-endpoint = <&rsnd_ep1>;
			};
			codec_2: endpoint@3 {
				remote-endpoint = <&rsnd_ep2>;
			};
			codec_3: endpoint@4 {
				remote-endpoint = <&rsnd_ep3>;
			};
		};
	};

	&rcar_sound {
		...
		ports {
			rsnd_port0: port@0 {
				rsnd_ep0: endpoint {
					remote-endpoint = <&codec_0>;
					...
					playback = <&ssiu30 &ssi3>;
				};
			};
			rsnd_port1: port@1 {
				rsnd_ep1: endpoint {
					remote-endpoint = <&codec_1>;
					...
					playback = <&ssiu31 &ssi3>;
				};
			};
			rsnd_port2: port@2 {
				rsnd_ep2: endpoint {
					remote-endpoint = <&codec_2>;
					...
					playback = <&ssiu32 &ssi3>;
				};
			};
			rsnd_port3: port@3 {
				rsnd_ep3: endpoint {
					remote-endpoint = <&codec_3>;
					...
					playback = <&ssiu33 &ssi3>;
				};
			};
		};
	};
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/core.c

@@ -271,6 +271,19 @@ int rsnd_runtime_channel_after_ctu_with_params(struct rsnd_dai_stream *io,
 	if (ctu_mod) {
 		u32 converted_chan = rsnd_io_converted_chan(io);
 
+		/*
+		 * !! Note !!
+		 *
+		 * converted_chan will be used for CTU,
+		 * or TDM Split mode.
+		 * User shouldn't use CTU with TDM Split mode.
+		 */
+		if (rsnd_runtime_is_tdm_split(io)) {
+			struct device *dev = rsnd_priv_to_dev(rsnd_io_to_priv(io));
+
+			dev_err(dev, "CTU and TDM Split should be used\n");
+		}
+
 		if (converted_chan)
 			return converted_chan;
 	}
@@ -313,6 +326,11 @@ int rsnd_runtime_is_tdm(struct rsnd_dai_stream *io)
 	return rsnd_runtime_channel_for_ssi(io) >= 6;
 }
 
+int rsnd_runtime_is_tdm_split(struct rsnd_dai_stream *io)
+{
+	return !!rsnd_flags_has(io, RSND_STREAM_TDM_SPLIT);
+}
+
 /*
  *	ADINR function
  */
@@ -790,6 +808,7 @@ static int rsnd_soc_set_dai_tdm_slot(struct snd_soc_dai *dai,
 
 	switch (slots) {
 	case 2:
+		/* TDM Split Mode */
 	case 6:
 	case 8:
 		/* TDM Extend Mode */
@@ -1010,6 +1029,7 @@ static void rsnd_parse_connect_graph(struct rsnd_priv *priv,
 				     struct device_node *endpoint)
 {
 	struct device *dev = rsnd_priv_to_dev(priv);
+	struct device_node *remote_port = of_graph_get_remote_port(endpoint);
 	struct device_node *remote_node = of_graph_get_remote_port_parent(endpoint);
 
 	if (!rsnd_io_to_mod_ssi(io))
@@ -1026,6 +1046,15 @@ static void rsnd_parse_connect_graph(struct rsnd_priv *priv,
 		rsnd_flags_set(io, RSND_STREAM_HDMI1);
 		dev_dbg(dev, "%s connected to HDMI1\n", io->name);
 	}
+
+	/*
+	 * This driver assumes that it is TDM Split mode
+	 * if remote node has multi endpoint
+	 */
+	if (of_get_child_count(remote_port) > 1) {
+		rsnd_flags_set(io, RSND_STREAM_TDM_SPLIT);
+		dev_dbg(dev, "%s is part of TDM Split\n", io->name);
+	}
 }
 
 void rsnd_parse_connect_common(struct rsnd_dai *rdai,

sound/soc/sh/rcar/rsnd.h

@@ -433,6 +433,7 @@ int rsnd_runtime_channel_for_ssi_with_params(struct rsnd_dai_stream *io,
 				 struct snd_pcm_hw_params *params);
 int rsnd_runtime_is_multi_ssi(struct rsnd_dai_stream *io);
 int rsnd_runtime_is_tdm(struct rsnd_dai_stream *io);
+int rsnd_runtime_is_tdm_split(struct rsnd_dai_stream *io);
 
 /*
  * DT
@@ -467,6 +468,7 @@ struct rsnd_dai_stream {
 /* flags */
 #define RSND_STREAM_HDMI0	(1 << 0) /* for HDMI0 */
 #define RSND_STREAM_HDMI1	(1 << 1) /* for HDMI1 */
+#define RSND_STREAM_TDM_SPLIT	(1 << 2) /* for TDM split mode */
 
 #define rsnd_io_to_mod(io, i)	((i) < RSND_MOD_MAX ? (io)->mod[(i)] : NULL)
 #define rsnd_io_to_mod_ssi(io)	rsnd_io_to_mod((io), RSND_MOD_SSI)

sound/soc/sh/rcar/ssi.c

@@ -298,6 +298,9 @@ static int rsnd_ssi_master_clk_start(struct rsnd_mod *mod,
 		return 0;
 	}
 
+	if (rsnd_runtime_is_tdm_split(io))
+		chan = rsnd_io_converted_chan(io);
+
 	main_rate = rsnd_ssi_clk_query(rdai, rate, chan, &idx);
 	if (!main_rate) {
 		dev_err(dev, "unsupported clock rate\n");
@@ -360,9 +363,11 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 	u32 cr_own	= ssi->cr_own;
 	u32 cr_mode	= ssi->cr_mode;
 	u32 wsr		= ssi->wsr;
-	int is_tdm;
+	int width;
+	int is_tdm, is_tdm_split;
 
 	is_tdm		= rsnd_runtime_is_tdm(io);
+	is_tdm_split	= rsnd_runtime_is_tdm_split(io);
 
 	cr_own |= FORCE | rsnd_rdai_width_to_swl(rdai);
 
@@ -381,7 +386,7 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 	 *	rsnd_ssiu_init_gen2()
 	 */
 	wsr = ssi->wsr;
-	if (is_tdm) {
+	if (is_tdm || is_tdm_split) {
 		wsr	|= WS_MODE;
 		cr_own	|= CHNL_8;
 	}
@@ -397,7 +402,18 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 		cr_own |= TRMD;
 
 	cr_own &= ~DWL_MASK;
-	switch (snd_pcm_format_width(runtime->format)) {
+	width = snd_pcm_format_width(runtime->format);
+	if (is_tdm_split) {
+		/*
+		 * The SWL and DWL bits in SSICR should be fixed at 32-bit
+		 * setting when TDM split mode.
+		 * see datasheet
+		 *	Operation :: TDM Format Split Function (TDM Split Mode)
+		 */
+		width = 32;
+	}
+
+	switch (width) {
 	case 8:
 		cr_own |= DWL_8;
 		break;
@@ -407,6 +423,9 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 	case 24:
 		cr_own |= DWL_24;
 		break;
+	case 32:
+		cr_own |= DWL_32;
+		break;
 	}
 
 	if (rsnd_ssi_is_dma_mode(mod)) {

sound/soc/sh/rcar/ssiu.c

@@ -16,6 +16,10 @@ struct rsnd_ssiu {
 	int id_sub;
 };
 
+/* SSI_MODE */
+#define TDM_EXT		(1 << 0)
+#define TDM_SPLIT	(1 << 8)
+
 #define rsnd_ssiu_nr(priv) ((priv)->ssiu_nr)
 #define rsnd_mod_to_ssiu(_mod) container_of((_mod), struct rsnd_ssiu, mod)
 #define for_each_rsnd_ssiu(pos, priv, i)				\
@@ -165,14 +169,15 @@ static int rsnd_ssiu_init_gen2(struct rsnd_mod *mod,
 
 	ssiu->usrcnt++;
 
-	if (rsnd_runtime_is_tdm(io)) {
 	/*
-		 * TDM Extend Mode
+	 * TDM Extend/Split Mode
 	 * see
 	 *	rsnd_ssi_config_init()
 	 */
-		mode = 0x1;
-	}
+	if (rsnd_runtime_is_tdm(io))
+		mode = TDM_EXT;
+	else if (rsnd_runtime_is_tdm_split(io))
+		mode = TDM_SPLIT;
 
 	rsnd_mod_write(mod, SSI_MODE, mode);