ASoC: rsnd: care DMA slave channel name for DT

Renesas sound driver is supporting to use DMAEngine.
But, DMA slave channel name "tx", "rx" is not enough
in DT case.
Becuase, it has many ports and path combination.

This patch adds rsnd_dma_of_name() to find
DMA channel name, for example
memory to SSI0 is "mem_ssi0",
SSI0 to memory is "ssi0_mem",
SSI0 to SRC0   is "ssi0_src0",
SRC0 to SSI0   is "src0_ssi0",
SRC0 to DVC0   is "src0_dvc0"...

Renesas sound want to use PIO transfer mode for some reasons.
It will be PIO tranfer mode if device node doesn't have
DMA settings.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Documentation/devicetree/bindings/sound/renesas,rsnd.txt

@@ -20,6 +20,7 @@ Required properties:
 SSI subnode properties:
 - interrupts			: Should contain SSI interrupt for PIO transfer
 - shared-pin			: if shared clock pin
+- pio-transfer			: use PIO transfer mode
 
 SRC subnode properties:
 no properties at this point

sound/soc/sh/rcar/core.c

@@ -256,11 +256,81 @@ int rsnd_dma_available(struct rsnd_dma *dma)
 	return !!dma->chan;
 }
 
+#define DMA_NAME_SIZE 16
+#define MOD_MAX 4 /* MEM/SSI/SRC/DVC */
+static int _rsnd_dma_of_name(char *dma_name, struct rsnd_mod *mod)
+{
+	if (mod)
+		return snprintf(dma_name, DMA_NAME_SIZE / 2, "%s%d",
+			 rsnd_mod_name(mod), rsnd_mod_id(mod));
+	else
+		return snprintf(dma_name, DMA_NAME_SIZE / 2, "mem");
+
+}
+
+static void rsnd_dma_of_name(struct rsnd_dma *dma,
+			     int is_play, char *dma_name)
+{
+	struct rsnd_mod *this = rsnd_dma_to_mod(dma);
+	struct rsnd_dai_stream *io = rsnd_mod_to_io(this);
+	struct rsnd_mod *ssi = rsnd_io_to_mod_ssi(io);
+	struct rsnd_mod *src = rsnd_io_to_mod_src(io);
+	struct rsnd_mod *dvc = rsnd_io_to_mod_dvc(io);
+	struct rsnd_mod *mod[MOD_MAX];
+	struct rsnd_mod *src_mod, *dst_mod;
+	int i, index;
+
+
+	for (i = 0; i < MOD_MAX; i++)
+		mod[i] = NULL;
+
+	/*
+	 * in play case...
+	 *
+	 * src -> dst
+	 *
+	 * mem -> SSI
+	 * mem -> SRC -> SSI
+	 * mem -> SRC -> DVC -> SSI
+	 */
+	mod[0] = NULL; /* for "mem" */
+	index = 1;
+	for (i = 1; i < MOD_MAX; i++) {
+		if (!src) {
+			mod[i] = ssi;
+			break;
+		} else if (!dvc) {
+			mod[i] = src;
+			src = NULL;
+		} else {
+			mod[i] = dvc;
+			dvc = NULL;
+		}
+
+		if (mod[i] == this)
+			index = i;
+	}
+
+	if (is_play) {
+		src_mod = mod[index - 1];
+		dst_mod = mod[index];
+	} else {
+		src_mod = mod[index];
+		dst_mod = mod[index + 1];
+	}
+
+	index = 0;
+	index = _rsnd_dma_of_name(dma_name + index, src_mod);
+	*(dma_name + index++) = '_';
+	index = _rsnd_dma_of_name(dma_name + index, dst_mod);
+}
+
 int rsnd_dma_init(struct rsnd_priv *priv, struct rsnd_dma *dma,
 		  int is_play, int id)
 {
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct dma_slave_config cfg;
+	char dma_name[DMA_NAME_SIZE];
 	dma_cap_mask_t mask;
 	int ret;
 
@@ -272,9 +342,17 @@ int rsnd_dma_init(struct rsnd_priv *priv, struct rsnd_dma *dma,
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
+	if (dev->of_node)
+		rsnd_dma_of_name(dma, is_play, dma_name);
+	else
+		snprintf(dma_name, DMA_NAME_SIZE,
+			 is_play ? "tx" : "rx");
+
+	dev_dbg(dev, "dma name : %s\n", dma_name);
+
 	dma->chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
 						     (void *)id, dev,
-						     is_play ? "tx" : "rx");
+						     dma_name);
 	if (!dma->chan) {
 		dev_err(dev, "can't get dma channel\n");
 		return -EIO;

sound/soc/sh/rcar/ssi.c

@@ -589,6 +589,12 @@ static void rsnd_of_parse_ssi(struct platform_device *pdev,
 		 * irq
 		 */
 		ssi_info->pio_irq = irq_of_parse_and_map(np, 0);
+
+		/*
+		 * DMA
+		 */
+		ssi_info->dma_id = of_get_property(np, "pio-transfer", NULL) ?
+			0 : 1;
 	}
 
 rsnd_of_parse_ssi_end: