ARM: OMAP2+: gpmc: add DT bindings for OneNAND

This patch adds device tree bindings for OMAP OneNAND devices.
Tested on an OMAP3 3430 IGEPv2 board.

Signed-off-by: Ezequiel Garcia <[e-mail]>
Signed-off-by: Tony Lindgren <[e-mail]>

Documentation/devicetree/bindings/mtd/gpmc-onenand.txt

···
+Device tree bindings for GPMC connected OneNANDs
+
+GPMC connected OneNAND (found on OMAP boards) are represented as child nodes of
+the GPMC controller with a name of "onenand".
+
+All timing relevant properties as well as generic gpmc child properties are
+explained in a separate documents - please refer to
+Documentation/devicetree/bindings/bus/ti-gpmc.txt
+
+Required properties:
+
+ - reg:			The CS line the peripheral is connected to
+
+Optional properties:
+
+ - dma-channel:		DMA Channel index
+
+For inline partiton table parsing (optional):
+
+ - #address-cells: should be set to 1
+ - #size-cells: should be set to 1
+
+Example for an OMAP3430 board:
+
+	gpmc: gpmc@6e000000 {
+		compatible = "ti,omap3430-gpmc";
+		ti,hwmods = "gpmc";
+		reg = <0x6e000000 0x1000000>;
+		interrupts = <20>;
+		gpmc,num-cs = <8>;
+		gpmc,num-waitpins = <4>;
+		#address-cells = <2>;
+		#size-cells = <1>;
+
+		onenand@0 {
+			reg = <0 0 0>; /* CS0, offset 0 */
+
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			/* partitions go here */
+		};
+	};

arch/arm/mach-omap2/gpmc.c

···
 #include "omap_device.h"
 #include "gpmc.h"
 #include "gpmc-nand.h"
+#include "gpmc-onenand.h"
 
 #define	DEVICE_NAME		"omap-gpmc"
 
···
 }
 #endif
 
+#ifdef CONFIG_MTD_ONENAND
+static int gpmc_probe_onenand_child(struct platform_device *pdev,
+				 struct device_node *child)
+{
+	u32 val;
+	struct omap_onenand_platform_data *gpmc_onenand_data;
+
+	if (of_property_read_u32(child, "reg", &val) < 0) {
+		dev_err(&pdev->dev, "%s has no 'reg' property\n",
+			child->full_name);
+		return -ENODEV;
+	}
+
+	gpmc_onenand_data = devm_kzalloc(&pdev->dev, sizeof(*gpmc_onenand_data),
+					 GFP_KERNEL);
+	if (!gpmc_onenand_data)
+		return -ENOMEM;
+
+	gpmc_onenand_data->cs = val;
+	gpmc_onenand_data->of_node = child;
+	gpmc_onenand_data->dma_channel = -1;
+
+	if (!of_property_read_u32(child, "dma-channel", &val))
+		gpmc_onenand_data->dma_channel = val;
+
+	gpmc_onenand_init(gpmc_onenand_data);
+
+	return 0;
+}
+#else
+static int gpmc_probe_onenand_child(struct platform_device *pdev,
+				    struct device_node *child)
+{
+	return 0;
+}
+#endif
+
 static int gpmc_probe_dt(struct platform_device *pdev)
 {
 	int ret;
···
 		}
 	}
 
+	for_each_node_by_name(child, "onenand") {
+		ret = gpmc_probe_onenand_child(pdev, child);
+		if (ret < 0) {
+			of_node_put(child);
+			return ret;
+		}
+	}
 	return 0;
 }
 #else