MTD: pxa3xx-nand: add devicetree bindings

This patch contains a hack to get the DMA resources of the device when
probed from a devicetree node. This can be removed once a generic DMA
controller framework lands.

A mtd_part_parser_data is passed mtd_device_parse_register which
contains a reference to the device node, so MTD partitions can be
added as children.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>

Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt

+PXA3xx NAND DT bindings
+
+Required properties:
+
+ - compatible:		Should be "marvell,pxa3xx-nand"
+ - reg: 		The register base for the controller
+ - interrupts:		The interrupt to map
+ - #address-cells:	Set to <1> if the node includes partitions
+
+Optional properties:
+
+ - marvell,nand-enable-arbiter:	Set to enable the bus arbiter
+ - marvell,nand-keep-config:	Set to keep the NAND controller config as set
+				by the bootloader
+ - num-cs:			Number of chipselect lines to usw
+
+Example:
+
+	nand0: nand@43100000 {
+		compatible = "marvell,pxa3xx-nand";
+		reg = <0x43100000 90>;
+		interrupts = <45>;
+		#address-cells = <1>;
+
+		marvell,nand-enable-arbiter;
+		marvell,nand-keep-config;
+		num-cs = <1>;
+
+		/* partitions (optional) */
+	};
+

drivers/mtd/nand/pxa3xx_nand.c

@@ -22,6 +22,8 @@
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <mach/dma.h>
 #include <plat/pxa3xx_nand.h>
@@ -1081,6 +1083,15 @@ static int alloc_nand_resource(struct platform_device *pdev)
 	}
 	clk_enable(info->clk);
 
+	/*
+	 * This is a dirty hack to make this driver work from devicetree
+	 * bindings. It can be removed once we have a prober DMA controller
+	 * framework for DT.
+	 */
+	if (pdev->dev.of_node && cpu_is_pxa3xx()) {
+		info->drcmr_dat = 97;
+		info->drcmr_cmd = 99;
+	} else {
 		r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 		if (r == NULL) {
 			dev_err(&pdev->dev, "no resource defined for data DMA\n");
@@ -1096,6 +1107,7 @@ static int alloc_nand_resource(struct platform_device *pdev)
 			goto fail_put_clk;
 		}
 		info->drcmr_cmd = r->start;
+	}
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
@@ -1200,12 +1212,55 @@ static int pxa3xx_nand_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static struct of_device_id pxa3xx_nand_dt_ids[] = {
+	{ .compatible = "marvell,pxa3xx-nand" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
+
+static int pxa3xx_nand_probe_dt(struct platform_device *pdev)
+{
+	struct pxa3xx_nand_platform_data *pdata;
+	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *of_id =
+			of_match_device(pxa3xx_nand_dt_ids, &pdev->dev);
+
+	if (!of_id)
+		return 0;
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	if (of_get_property(np, "marvell,nand-enable-arbiter", NULL))
+		pdata->enable_arbiter = 1;
+	if (of_get_property(np, "marvell,nand-keep-config", NULL))
+		pdata->keep_config = 1;
+	of_property_read_u32(np, "num-cs", &pdata->num_cs);
+
+	pdev->dev.platform_data = pdata;
+
+	return 0;
+}
+#else
+static inline int pxa3xx_nand_probe_dt(struct platform_device *)
+{
+	return 0;
+}
+#endif
+
 static int pxa3xx_nand_probe(struct platform_device *pdev)
 {
 	struct pxa3xx_nand_platform_data *pdata;
+	struct mtd_part_parser_data ppdata = {};
 	struct pxa3xx_nand_info *info;
 	int ret, cs, probe_success;
 
+	ret = pxa3xx_nand_probe_dt(pdev);
+	if (ret)
+		return ret;
+
 	pdata = pdev->dev.platform_data;
 	if (!pdata) {
 		dev_err(&pdev->dev, "no platform data defined\n");
@@ -1229,8 +1284,9 @@ static int pxa3xx_nand_probe(struct platform_device *pdev)
 			continue;
 		}
 
+		ppdata.of_node = pdev->dev.of_node;
 		ret = mtd_device_parse_register(info->host[cs]->mtd, NULL,
-						NULL, pdata->parts[cs],
+						&ppdata, pdata->parts[cs],
 						pdata->nr_parts[cs]);
 		if (!ret)
 			probe_success = 1;
@@ -1306,6 +1362,7 @@ static int pxa3xx_nand_resume(struct platform_device *pdev)
 static struct platform_driver pxa3xx_nand_driver = {
 	.driver = {
 		.name	= "pxa3xx-nand",
+		.of_match_table = of_match_ptr(pxa3xx_nand_dt_ids),
 	},
 	.probe		= pxa3xx_nand_probe,
 	.remove		= pxa3xx_nand_remove,