ASoC: rsnd: SSI supports DMA transfer via BUSIF

This patch adds BUSIF support for R-Car sound DMAEngine transfer.
The sound data will be transferred via FIFO which can cover blank time
which will happen when DMA channel is switching.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/rcar_snd.h

@@ -36,6 +36,7 @@
 #define RSND_SSI_CLK_PIN_SHARE		(1 << 31)
 #define RSND_SSI_CLK_FROM_ADG		(1 << 30) /* clock parent is master */
 #define RSND_SSI_SYNC			(1 << 29) /* SSI34_sync etc */
+#define RSND_SSI_DEPENDENT		(1 << 28) /* SSI needs SRU/SCU */
 
 #define RSND_SSI_PLAY			(1 << 24)
 
@@ -51,6 +52,11 @@ struct rsnd_ssi_platform_info {
 	u32 flags;
 };
 
+/*
+ * flags
+ */
+#define RSND_SCU_USB_HPBIF		(1 << 31) /* it needs RSND_SSI_DEPENDENT */
+
 struct rsnd_scu_platform_info {
 	u32 flags;
 };

sound/soc/sh/rcar/gen.c

@@ -34,9 +34,6 @@ struct rsnd_gen {
 
 #define rsnd_priv_to_gen(p)	((struct rsnd_gen *)(p)->gen)
 
-#define rsnd_is_gen1(s)		((s)->info->flags & RSND_GEN1)
-#define rsnd_is_gen2(s)		((s)->info->flags & RSND_GEN2)
-
 /*
  *		Gen2
  *		will be filled in the future
@@ -115,8 +112,15 @@ static struct rsnd_gen_ops rsnd_gen1_ops = {
 
 static void rsnd_gen1_reg_map_init(struct rsnd_gen *gen)
 {
+	RSND_GEN1_REG_MAP(gen, SRU,	SRC_ROUTE_SEL,	0x0,	0x00);
+	RSND_GEN1_REG_MAP(gen, SRU,	SRC_TMG_SEL0,	0x0,	0x08);
+	RSND_GEN1_REG_MAP(gen, SRU,	SRC_TMG_SEL1,	0x0,	0x0c);
+	RSND_GEN1_REG_MAP(gen, SRU,	SRC_TMG_SEL2,	0x0,	0x10);
+	RSND_GEN1_REG_MAP(gen, SRU,	SRC_CTRL,	0x0,	0xc0);
 	RSND_GEN1_REG_MAP(gen, SRU,	SSI_MODE0,	0x0,	0xD0);
 	RSND_GEN1_REG_MAP(gen, SRU,	SSI_MODE1,	0x0,	0xD4);
+	RSND_GEN1_REG_MAP(gen, SRU,	BUSIF_MODE,	0x4,	0x20);
+	RSND_GEN1_REG_MAP(gen, SRU,	BUSIF_ADINR,	0x40,	0x214);
 
 	RSND_GEN1_REG_MAP(gen, ADG,	BRRA,		0x0,	0x00);
 	RSND_GEN1_REG_MAP(gen, ADG,	BRRB,		0x0,	0x04);

sound/soc/sh/rcar/rsnd.h

@@ -32,8 +32,15 @@
  */
 enum rsnd_reg {
 	/* SRU/SCU */
+	RSND_REG_SRC_ROUTE_SEL,
+	RSND_REG_SRC_TMG_SEL0,
+	RSND_REG_SRC_TMG_SEL1,
+	RSND_REG_SRC_TMG_SEL2,
+	RSND_REG_SRC_CTRL,
 	RSND_REG_SSI_MODE0,
 	RSND_REG_SSI_MODE1,
+	RSND_REG_BUSIF_MODE,
+	RSND_REG_BUSIF_ADINR,
 
 	/* ADG */
 	RSND_REG_BRRA,
@@ -213,6 +220,8 @@ int rsnd_gen_path_exit(struct rsnd_priv *priv,
 void __iomem *rsnd_gen_reg_get(struct rsnd_priv *priv,
 			       struct rsnd_mod *mod,
 			       enum rsnd_reg reg);
+#define rsnd_is_gen1(s)		((s)->info->flags & RSND_GEN1)
+#define rsnd_is_gen2(s)		((s)->info->flags & RSND_GEN2)
 
 /*
  *	R-Car ADG

sound/soc/sh/rcar/scu.c

@@ -15,6 +15,18 @@ struct rsnd_scu {
 	struct rsnd_mod mod;
 };
 
+#define rsnd_scu_mode_flags(p) ((p)->info->flags)
+
+/*
+ * ADINR
+ */
+#define OTBL_24		(0 << 16)
+#define OTBL_22		(2 << 16)
+#define OTBL_20		(4 << 16)
+#define OTBL_18		(6 << 16)
+#define OTBL_16		(8 << 16)
+
+
 #define rsnd_mod_to_scu(_mod)	\
 	container_of((_mod), struct rsnd_scu, mod)
 
@@ -24,6 +36,116 @@ struct rsnd_scu {
 		     ((pos) = (struct rsnd_scu *)(priv)->scu + i);	\
 	     i++)
 
+static int rsnd_scu_set_route(struct rsnd_priv *priv,
+			      struct rsnd_mod *mod,
+			      struct rsnd_dai *rdai,
+			      struct rsnd_dai_stream *io)
+{
+	struct scu_route_config {
+		u32 mask;
+		int shift;
+	} routes[] = {
+		{ 0xF,  0, }, /* 0 */
+		{ 0xF,  4, }, /* 1 */
+		{ 0xF,  8, }, /* 2 */
+		{ 0x7, 12, }, /* 3 */
+		{ 0x7, 16, }, /* 4 */
+		{ 0x7, 20, }, /* 5 */
+		{ 0x7, 24, }, /* 6 */
+		{ 0x3, 28, }, /* 7 */
+		{ 0x3, 30, }, /* 8 */
+	};
+
+	u32 mask;
+	u32 val;
+	int shift;
+	int id;
+
+	/*
+	 * Gen1 only
+	 */
+	if (!rsnd_is_gen1(priv))
+		return 0;
+
+	id = rsnd_mod_id(mod);
+	if (id < 0 || id > ARRAY_SIZE(routes))
+		return -EIO;
+
+	/*
+	 * SRC_ROUTE_SELECT
+	 */
+	val = rsnd_dai_is_play(rdai, io) ? 0x1 : 0x2;
+	val = val		<< routes[id].shift;
+	mask = routes[id].mask	<< routes[id].shift;
+
+	rsnd_mod_bset(mod, SRC_ROUTE_SEL, mask, val);
+
+	/*
+	 * SRC_TIMING_SELECT
+	 */
+	shift	= (id % 4) * 8;
+	mask	= 0x1F << shift;
+	if (8 == id) /* SRU8 is very special */
+		val = id << shift;
+	else
+		val = (id + 1) << shift;
+
+	switch (id / 4) {
+	case 0:
+		rsnd_mod_bset(mod, SRC_TMG_SEL0, mask, val);
+		break;
+	case 1:
+		rsnd_mod_bset(mod, SRC_TMG_SEL1, mask, val);
+		break;
+	case 2:
+		rsnd_mod_bset(mod, SRC_TMG_SEL2, mask, val);
+		break;
+	}
+
+	return 0;
+}
+
+static int rsnd_scu_set_mode(struct rsnd_priv *priv,
+			     struct rsnd_mod *mod,
+			     struct rsnd_dai *rdai,
+			     struct rsnd_dai_stream *io)
+{
+	int id = rsnd_mod_id(mod);
+	u32 val;
+
+	if (rsnd_is_gen1(priv)) {
+		val = (1 << id);
+		rsnd_mod_bset(mod, SRC_CTRL, val, val);
+	}
+
+	return 0;
+}
+
+static int rsnd_scu_set_hpbif(struct rsnd_priv *priv,
+			      struct rsnd_mod *mod,
+			      struct rsnd_dai *rdai,
+			      struct rsnd_dai_stream *io)
+{
+	struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);
+	u32 adinr = runtime->channels;
+
+	switch (runtime->sample_bits) {
+	case 16:
+		adinr |= OTBL_16;
+		break;
+	case 32:
+		adinr |= OTBL_24;
+		break;
+	default:
+		return -EIO;
+	}
+
+	rsnd_mod_write(mod, BUSIF_MODE, 1);
+	rsnd_mod_write(mod, BUSIF_ADINR, adinr);
+
+	return 0;
+}
+
 static int rsnd_scu_init(struct rsnd_mod *mod,
 			 struct rsnd_dai *rdai,
 			 struct rsnd_dai_stream *io)
@@ -53,9 +175,36 @@ static int rsnd_scu_start(struct rsnd_mod *mod,
 			  struct rsnd_dai_stream *io)
 {
 	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
+	struct rsnd_scu *scu = rsnd_mod_to_scu(mod);
 	struct device *dev = rsnd_priv_to_dev(priv);
+	u32 flags = rsnd_scu_mode_flags(scu);
+	int ret;
+
+	/*
+	 * SCU will be used if it has RSND_SCU_USB_HPBIF flags
+	 */
+	if (!(flags & RSND_SCU_USB_HPBIF)) {
+		/* it use PIO transter */
+		dev_dbg(dev, "%s%d is not used\n",
+			rsnd_mod_name(mod), rsnd_mod_id(mod));
+
+		return 0;
+	}
+
+	/* it use DMA transter */
+	ret = rsnd_scu_set_route(priv, mod, rdai, io);
+	if (ret < 0)
+		return ret;
+
+	ret = rsnd_scu_set_mode(priv, mod, rdai, io);
+	if (ret < 0)
+		return ret;
 
-	dev_dbg(dev, "%s.%d start\n", rsnd_mod_name(mod), rsnd_mod_id(mod));
+	ret = rsnd_scu_set_hpbif(priv, mod, rdai, io);
+	if (ret < 0)
+		return ret;
+
+	dev_dbg(dev, "%s%d start\n", rsnd_mod_name(mod), rsnd_mod_id(mod));
 
 	return 0;
 }
@@ -112,8 +261,9 @@ int rsnd_scu_probe(struct platform_device *pdev,
 		rsnd_mod_init(priv, &scu->mod,
 			      &rsnd_scu_ops, i);
 		scu->info = &info->scu_info[i];
-	}
 
+		dev_dbg(dev, "SCU%d probed\n", i);
+	}
 	dev_dbg(dev, "scu probed\n");
 
 	return 0;

sound/soc/sh/rcar/ssi.c

@@ -104,6 +104,7 @@ struct rsnd_ssiu {
 static void rsnd_ssi_mode_init(struct rsnd_priv *priv,
 			       struct rsnd_ssiu *ssiu)
 {
+	struct device *dev = rsnd_priv_to_dev(priv);
 	struct rsnd_ssi *ssi;
 	u32 flags;
 	u32 val;
@@ -113,8 +114,17 @@ static void rsnd_ssi_mode_init(struct rsnd_priv *priv,
 	 * SSI_MODE0
 	 */
 	ssiu->ssi_mode0 = 0;
-	for_each_rsnd_ssi(ssi, priv, i)
-		ssiu->ssi_mode0 |= (1 << i);
+	for_each_rsnd_ssi(ssi, priv, i) {
+		flags = rsnd_ssi_mode_flags(ssi);
+
+		/* see also BUSIF_MODE */
+		if (!(flags & RSND_SSI_DEPENDENT)) {
+			ssiu->ssi_mode0 |= (1 << i);
+			dev_dbg(dev, "SSI%d uses INDEPENDENT mode\n", i);
+		} else {
+			dev_dbg(dev, "SSI%d uses DEPENDENT mode\n", i);
+		}
+	}
 
 	/*
 	 * SSI_MODE1
@@ -670,6 +680,8 @@ int rsnd_ssi_probe(struct platform_device *pdev,
 				dev_info(dev, "SSI DMA failed. try PIO transter\n");
 			else
 				ops	= &rsnd_ssi_dma_ops;
+
+			dev_dbg(dev, "SSI%d use DMA transfer\n", i);
 		}
 
 		/*
@@ -687,6 +699,8 @@ int rsnd_ssi_probe(struct platform_device *pdev,
 			}
 
 			ops	= &rsnd_ssi_pio_ops;
+
+			dev_dbg(dev, "SSI%d use PIO transfer\n", i);
 		}
 
 		rsnd_mod_init(priv, &ssi->mod, ops, i);