dma: rcar-audmapp: add DT support

This patch adds DT support to Audio DMAC peri peri driver.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
[horms+renesas@verge.net.au: Do not add trailing blank line to rcar-audmapp.txt]
[horms+renesas@verge.net.au: squashed patch to add NULL terminater to audmapp_of_match]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

Documentation/devicetree/bindings/dma/rcar-audmapp.txt

@@ -0,0 +1,29 @@
+* R-Car Audio DMAC peri peri Device Tree bindings
+
+Required properties:
+- compatible:	should be "renesas,rcar-audmapp"
+- #dma-cells:	should be <1>, see "dmas" property below
+
+Example:
+	audmapp: audio-dma-pp@0xec740000 {
+		compatible = "renesas,rcar-audmapp";
+		#dma-cells = <1>;
+
+		reg = <0 0xec740000 0 0x200>;
+	};
+
+
+* DMA client
+
+Required properties:
+- dmas:		a list of <[DMA multiplexer phandle] [SRS/DRS value]> pairs,
+		where SRS/DRS values are fixed handles, specified in the SoC
+		manual as the value that would be written into the PDMACHCR.
+- dma-names:	a list of DMA channel names, one per "dmas" entry
+
+Example:
+
+	dmas = <&audmapp 0x2d00
+		&audmapp 0x3700>;
+	dma-names =  "src0_ssiu0",
+		     "dvc0_ssiu0";

drivers/dma/sh/rcar-audmapp.c

@@ -22,6 +22,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/dmaengine.h>
+#include <linux/of_dma.h>
 #include <linux/platform_data/dma-rcar-audmapp.h>
 #include <linux/platform_device.h>
 #include <linux/shdma-base.h>
@@ -63,6 +64,8 @@ struct audmapp_desc {
 	dma_addr_t dst;
 };
 
+#define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan)
+
 #define to_chan(chan) container_of(chan, struct audmapp_chan, shdma_chan)
 #define to_desc(sdesc) container_of(sdesc, struct audmapp_desc, shdma_desc)
 #define to_dev(chan) container_of(chan->shdma_chan.dma_chan.device,	\
@@ -114,38 +117,50 @@ static void audmapp_start_xfer(struct shdma_chan *schan,
 	audmapp_write(auchan, chcr,	PDMACHCR);
 }
 
-static struct audmapp_slave_config *
+static void audmapp_get_config(struct audmapp_chan *auchan, int slave_id,
-audmapp_find_slave(struct audmapp_chan *auchan, int slave_id)
+			      u32 *chcr, dma_addr_t *dst)
 {
 	struct audmapp_device *audev = to_dev(auchan);
 	struct audmapp_pdata *pdata = audev->pdata;
 	struct audmapp_slave_config *cfg;
 	int i;
 
+	*chcr	= 0;
+	*dst	= 0;
+
+	if (!pdata) { /* DT */
+		*chcr = ((u32)slave_id) << 16;
+		auchan->shdma_chan.slave_id = (slave_id) >> 8;
+		return;
+	}
+
+	/* non-DT */
+
 	if (slave_id >= AUDMAPP_SLAVE_NUMBER)
-		return NULL;
+		return;
 
 	for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
-		if (cfg->slave_id == slave_id)
+		if (cfg->slave_id == slave_id) {
-			return cfg;
+			*chcr	= cfg->chcr;
-
+			*dst	= cfg->dst;
-	return NULL;
+			break;
+		}
 }
 
 static int audmapp_set_slave(struct shdma_chan *schan, int slave_id,
 			     dma_addr_t slave_addr, bool try)
 {
 	struct audmapp_chan *auchan = to_chan(schan);
-	struct audmapp_slave_config *cfg =
+	u32 chcr;
-		audmapp_find_slave(auchan, slave_id);
+	dma_addr_t dst;
+
+	audmapp_get_config(auchan, slave_id, &chcr, &dst);
 
-	if (!cfg)
-		return -ENODEV;
 	if (try)
 		return 0;
 
-	auchan->chcr	= cfg->chcr;
+	auchan->chcr		= chcr;
-	auchan->slave_addr = slave_addr ? : cfg->dst;
+	auchan->slave_addr	= slave_addr ? : dst;
 
 	return 0;
 }
@@ -244,16 +259,39 @@ static void audmapp_chan_remove(struct audmapp_device *audev)
 	dma_dev->chancnt = 0;
 }
 
+static struct dma_chan *audmapp_of_xlate(struct of_phandle_args *dma_spec,
+					 struct of_dma *ofdma)
+{
+	dma_cap_mask_t mask;
+	struct dma_chan *chan;
+	u32 chcr = dma_spec->args[0];
+
+	if (dma_spec->args_count != 1)
+		return NULL;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	chan = dma_request_channel(mask, shdma_chan_filter, NULL);
+	if (chan)
+		to_shdma_chan(chan)->hw_req = chcr;
+
+	return chan;
+}
+
 static int audmapp_probe(struct platform_device *pdev)
 {
 	struct audmapp_pdata *pdata = pdev->dev.platform_data;
+	struct device_node *np = pdev->dev.of_node;
 	struct audmapp_device *audev;
 	struct shdma_dev *sdev;
 	struct dma_device *dma_dev;
 	struct resource *res;
 	int err, i;
 
-	if (!pdata)
+	if (np)
+		of_dma_controller_register(np, audmapp_of_xlate, pdev);
+	else if (!pdata)
 		return -ENODEV;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -315,12 +353,18 @@ static int audmapp_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct of_device_id audmapp_of_match[] = {
+	{ .compatible = "renesas,rcar-audmapp", },
+	{},
+};
+
 static struct platform_driver audmapp_driver = {
 	.probe		= audmapp_probe,
 	.remove		= audmapp_remove,
 	.driver		= {
 		.owner	= THIS_MODULE,
 		.name	= "rcar-audmapp-engine",
+		.of_match_table = audmapp_of_match,
 	},
 };
 module_platform_driver(audmapp_driver);