mtd: sh_flctl: Add device tree support

The flctl can now be probed via device tree setup in addition to the
existing platform data way.

SoC specific setup data is set in the .data member of the OF match, so
kept within the driver itself, while board/user specific setup - like
partitioning - is taken from the device tree.

Actual configuration is added for the SoC sh7372.

Signed-off-by: Bastian Hecht <[e-mail]>
Signed-off-by: Artem Bityutskiy <[e-mail]>

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

···
+FLCTL NAND controller
+
+Required properties:
+- compatible : "renesas,shmobile-flctl-sh7372"
+- reg : Address range of the FLCTL
+- interrupts : flste IRQ number
+- nand-bus-width : bus width to NAND chip
+
+Optional properties:
+- dmas: DMA specifier(s)
+- dma-names: name for each DMA specifier. Valid names are
+	     "data_tx", "data_rx", "ecc_tx", "ecc_rx"
+
+The DMA fields are not used yet in the driver but are listed here for
+completing the bindings.
+
+The device tree may optionally contain sub-nodes describing partitions of the
+address space. See partition.txt for more detail.
+
+Example:
+
+	flctl@e6a30000 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "renesas,shmobile-flctl-sh7372";
+		reg = <0xe6a30000 0x100>;
+		interrupts = <0x0d80>;
+
+		nand-bus-width = <16>;
+
+		dmas = <&dmac 1 /* data_tx */
+			&dmac 2;> /* data_rx */
+		dma-names = "data_tx", "data_rx";
+
+		system@0 {
+			label = "system";
+			reg = <0x0 0x8000000>;
+		};
+
+		userdata@8000000 {
+			label = "userdata";
+			reg = <0x8000000 0x10000000>;
+		};
+
+		cache@18000000 {
+			label = "cache";
+			reg = <0x18000000 0x8000000>;
+		};
+	};

drivers/mtd/nand/sh_flctl.c

···
 #include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_mtd.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/sh_dma.h>
···
 	return IRQ_HANDLED;
 }
 
+#ifdef CONFIG_OF
+struct flctl_soc_config {
+	unsigned long flcmncr_val;
+	unsigned has_hwecc:1;
+	unsigned use_holden:1;
+};
+
+static struct flctl_soc_config flctl_sh7372_config = {
+	.flcmncr_val = CLK_16B_12L_4H | TYPESEL_SET | SHBUSSEL,
+	.has_hwecc = 1,
+	.use_holden = 1,
+};
+
+static const struct of_device_id of_flctl_match[] = {
+	{ .compatible = "renesas,shmobile-flctl-sh7372",
+				.data = &flctl_sh7372_config },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_flctl_match);
+
+static struct sh_flctl_platform_data *flctl_parse_dt(struct device *dev)
+{
+	const struct of_device_id *match;
+	struct flctl_soc_config *config;
+	struct sh_flctl_platform_data *pdata;
+	struct device_node *dn = dev->of_node;
+	int ret;
+
+	match = of_match_device(of_flctl_match, dev);
+	if (match)
+		config = (struct flctl_soc_config *)match->data;
+	else {
+		dev_err(dev, "%s: no OF configuration attached\n", __func__);
+		return NULL;
+	}
+
+	pdata = devm_kzalloc(dev, sizeof(struct sh_flctl_platform_data),
+								GFP_KERNEL);
+	if (!pdata) {
+		dev_err(dev, "%s: failed to allocate config data\n", __func__);
+		return NULL;
+	}
+
+	/* set SoC specific options */
+	pdata->flcmncr_val = config->flcmncr_val;
+	pdata->has_hwecc = config->has_hwecc;
+	pdata->use_holden = config->use_holden;
+
+	/* parse user defined options */
+	ret = of_get_nand_bus_width(dn);
+	if (ret == 16)
+		pdata->flcmncr_val |= SEL_16BIT;
+	else if (ret != 8) {
+		dev_err(dev, "%s: invalid bus width\n", __func__);
+		return NULL;
+	}
+
+	return pdata;
+}
+#else /* CONFIG_OF */
+#define of_flctl_match NULL
+static struct sh_flctl_platform_data *flctl_parse_dt(struct device *dev)
+{
+	return NULL;
+}
+#endif /* CONFIG_OF */
+
 static int __devinit flctl_probe(struct platform_device *pdev)
 {
 	struct resource *res;
···
 	struct sh_flctl_platform_data *pdata;
 	int ret = -ENXIO;
 	int irq;
-
-	pdata = pdev->dev.platform_data;
-	if (pdata == NULL) {
-		dev_err(&pdev->dev, "no platform data defined\n");
-		return -EINVAL;
-	}
+	struct mtd_part_parser_data ppdata = {};
 
 	flctl = kzalloc(sizeof(struct sh_flctl), GFP_KERNEL);
 	if (!flctl) {
···
 	if (ret) {
 		dev_err(&pdev->dev, "request interrupt failed.\n");
 		goto err_flste;
+	}
+
+	if (pdev->dev.of_node)
+		pdata = flctl_parse_dt(&pdev->dev);
+	else
+		pdata = pdev->dev.platform_data;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "no setup data defined\n");
+		ret = -EINVAL;
+		goto err_pdata;
 	}
 
 	platform_set_drvdata(pdev, flctl);
···
 	if (ret)
 		goto err_chip;
 
-	mtd_device_register(flctl_mtd, pdata->parts, pdata->nr_parts);
+	ppdata.of_node = pdev->dev.of_node;
+	ret = mtd_device_parse_register(flctl_mtd, NULL, &ppdata, pdata->parts,
+			pdata->nr_parts);
 
 	return 0;
 
 err_chip:
 	flctl_release_dma(flctl);
 	pm_runtime_disable(&pdev->dev);
+err_pdata:
 	free_irq(irq, flctl);
 err_flste:
 	iounmap(flctl->reg);
···
 	.driver = {
 		.name	= "sh_flctl",
 		.owner	= THIS_MODULE,
+		.of_match_table = of_flctl_match,
 	},
 };