Subject: [PATCH 3/5] ARM: pxa: ssp: add DT bindings

From: [email-masked] (Daniel Mack)
Date: Mon, 12 Aug 2013 10:37:16 +0200

This patch contains an ugly hack for looking up the the DMA request
number. The problem here is that the implementation as it stands will
allocate the DMA channel from the user of the ssp port, and hence we
cannot allocate a real channel here.

Signed-off-by: Daniel Mack <[email-masked]>
---
 .../devicetree/bindings/serial/mrvl,pxa-ssp.txt    | 65 ++++++++++++++++
 arch/arm/plat-pxa/ssp.c                            | 90 +++++++++++++++++-----
 2 files changed, 134 insertions(+), 21 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/serial/mrvl,pxa-ssp.txt

diff --git a/Documentation/devicetree/bindings/serial/mrvl,pxa-ssp.txt b/Documentation/devicetree/bindings/serial/mrvl,pxa-ssp.txt
new file mode 100644
index 0000000..669b814
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/mrvl,pxa-ssp.txt
@@ -0,0 +1,65 @@
+Device tree bindings for Marvell PXA SSP ports
+
+Required properties:
+
+	- compatible:	Must be one of
+				mrvl,pxa25x-ssp
+				mvrl,pxa25x-nssp
+				mrvl,pxa27x-ssp
+				mrvl,pxa3xx-ssp
+				mvrl,pxa168-ssp
+				mrvl,pxa910-ssp
+				mrvl,ce4100-ssp
+				mrvl,lpss-ssp
+
+	- reg:		The memory base
+	- dmas:		Two dma phandles, one for rx, one for tx
+	- dma-names:	Must be "rx", "tx"
+
+
+Example for PXA3xx:
+
+	ssp0: ssp at 41000000 {
+		compatible = "mrvl,pxa3xx-ssp";
+		reg = <0x41000000 0x40>;
+		ssp-id = <1>;
+		interrupts = <24>;
+		clock-names = "pxa27x-ssp.0";
+		dmas = <&dma 13
+			&dma 14>;
+		dma-names = "rx", "tx";
+	};
+
+	ssp1: ssp at 41700000 {
+		compatible = "mrvl,pxa3xx-ssp";
+		reg = <0x41700000 0x40>;
+		ssp-id = <2>;
+		interrupts = <16>;
+		clock-names = "pxa27x-ssp.1";
+		dmas = <&dma 15
+			&dma 16>;
+		dma-names = "rx", "tx";
+	};
+
+	ssp2: ssp at 41900000 {
+		compatibl3 = "mrvl,pxa3xx-ssp";
+		reg = <0x41900000 0x40>;
+		ssp-id = <3>;
+		interrupts = <0>;
+		clock-names = "pxa27x-ssp.2";
+		dmas = <&dma 66
+			&dma 67>;
+		dma-names = "rx", "tx";
+	};
+
+	ssp3: ssp at 41a00000 {
+		compatible = "mrvl,pxa3xx-ssp";
+		reg = <0x41a00000 0x40>;
+		ssp-id = <4>;
+		interrupts = <13>;
+		clock-names = "pxa27x-ssp.3";
+		dmas = <&dma 2
+			&dma 3>;
+		dma-names = "rx", "tx";
+	};
+
diff --git a/arch/arm/plat-pxa/ssp.c b/arch/arm/plat-pxa/ssp.c
index 65ba28a..c3afcec 100644
--- a/arch/arm/plat-pxa/ssp.c
+++ b/arch/arm/plat-pxa/ssp.c
@@ -30,6 +30,8 @@
 #include <linux/platform_device.h>
 #include <linux/spi/pxa2xx_spi.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <asm/irq.h>
 #include <mach/hardware.h>
@@ -72,9 +74,23 @@ void pxa_ssp_free(struct ssp_device *ssp)
 }
 EXPORT_SYMBOL(pxa_ssp_free);
 
+#ifdef CONFIG_OF
+static const struct of_device_id pxa_ssp_of_ids[] = {
+	{ .compatible = "mrvl,pxa25x-ssp",	.data = (void *) PXA25x_SSP },
+	{ .compatible = "mvrl,pxa25x-nssp",	.data = (void *) PXA25x_NSSP },
+	{ .compatible = "mrvl,pxa27x-ssp",	.data = (void *) PXA27x_SSP },
+	{ .compatible = "mrvl,pxa3xx-ssp",	.data = (void *) PXA3xx_SSP },
+	{ .compatible = "mvrl,pxa168-ssp",	.data = (void *) PXA168_SSP },
+	{ .compatible = "mrvl,pxa910-ssp",	.data = (void *) PXA910_SSP },
+	{ .compatible = "mrvl,ce4100-ssp",	.data = (void *) CE4100_SSP },
+	{ .compatible = "mrvl,lpss-ssp",	.data = (void *) LPSS_SSP },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
+#endif
+
 static int pxa_ssp_probe(struct platform_device *pdev)
 {
-	const struct platform_device_id *id = platform_get_device_id(pdev);
 	struct resource *res;
 	struct ssp_device *ssp;
 	struct device *dev = &pdev->dev;
@@ -92,21 +108,42 @@ static int pxa_ssp_probe(struct platform_device *pdev)
 		goto err_free;
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
-	if (res == NULL) {
-		dev_err(dev, "no SSP RX DRCMR defined\n");
-		ret = -ENODEV;
-		goto err_free_clk;
-	}
-	ssp->drcmr_rx = res->start;
+	if (dev->of_node) {
+		struct of_phandle_args dma_spec;
+		struct device_node *np = dev->of_node;
+
+		/*
+		 * FIXME: we should allocate the DMA channel from this
+		 * context and pass the channel down to the ssp users.
+		 * For now, we lookup the rx and tx indices manually
+		 */
+
+		/* rx */
+		of_parse_phandle_with_args(np, "dmas", "#dma-cells",
+					   0, &dma_spec);
+		ssp->drcmr_rx = dma_spec.args[0];
+		of_node_put(dma_spec.np);
+
+		/* tx */
+		of_parse_phandle_with_args(np, "dmas", "#dma-cells",
+					   1, &dma_spec);
+		ssp->drcmr_tx = dma_spec.args[0];
+		of_node_put(dma_spec.np);
+	} else {
+		res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+		if (res == NULL) {
+			dev_err(dev, "no SSP RX DRCMR defined\n");
+			return -ENODEV;
+		}
+		ssp->drcmr_rx = res->start;
 
-	res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
-	if (res == NULL) {
-		dev_err(dev, "no SSP TX DRCMR defined\n");
-		ret = -ENODEV;
-		goto err_free_clk;
+		res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
+		if (res == NULL) {
+			dev_err(dev, "no SSP TX DRCMR defined\n");
+			return -ENODEV;
+		}
+		ssp->drcmr_tx = res->start;
 	}
-	ssp->drcmr_tx = res->start;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (res == NULL) {
@@ -139,12 +176,22 @@ static int pxa_ssp_probe(struct platform_device *pdev)
 		goto err_free_io;
 	}
 
-	/* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
-	 * starts from 0, do a translation here
-	 */
-	ssp->port_id = pdev->id + 1;
+	if (dev->of_node) {
+		const struct of_device_id *id =
+			of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
+		ssp->type = (int) id->data;
+	} else {
+		const struct platform_device_id *id =
+			platform_get_device_id(pdev);
+		ssp->type = (int) id->driver_data;
+
+		/* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
+		 * starts from 0, do a translation here
+		 */
+		ssp->port_id = pdev->id + 1;
+	}
+
 	ssp->use_count = 0;
-	ssp->type = (int)id->driver_data;
 
 	mutex_lock(&ssp_lock);
 	list_add(&ssp->node, &ssp_list);
@@ -201,8 +248,9 @@ static struct platform_driver pxa_ssp_driver = {
 	.probe		= pxa_ssp_probe,
 	.remove		= pxa_ssp_remove,
 	.driver		= {
-		.owner	= THIS_MODULE,
-		.name	= "pxa2xx-ssp",
+		.owner		= THIS_MODULE,
+		.name		= "pxa2xx-ssp",
+		.of_match_table	= of_match_ptr(pxa_ssp_of_ids),
 	},
 	.id_table	= ssp_id_table,
 };
-- 
1.8.3.1