[RFC PATCH] SDHCI: S3C: Add support for retrieving memory and irq resource information from device tree.

[thomas.abraham-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org]

From: Thomas Abraham <thomas.abraham-68IGFXMjmZ7QT0dZR+AlfA@public.gmane.org>

Add support for retrieving memory and irq resource information
from device tree for Samsung's SDHCI controller driver.

Signed-off-by: Thomas Abraham <thomas.abraham-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---

The modification will be made more generic to support both
DT and non-DT versions of the driver without the #ifdef's.
For now, this patch is for review and to understand if the
approach adopted to obtain resource information from the
device tree is appropriate.

 drivers/mmc/host/sdhci-s3c.c |   32 ++++++++++++++++++++++++++++++++
 1 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index 1720358..f536061 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -19,6 +19,9 @@
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
 
 #include <linux/mmc/host.h>
 
@@ -348,23 +351,52 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
 	struct sdhci_s3c *sc;
 	struct resource *res;
 	int ret, irq, ptr, clks;
+	struct device_node *np = NULL;
+#ifdef CONFIG_OF
+	struct resource iores;
+#endif
 
 	if (!pdata) {
 		dev_err(dev, "no device data specified\n");
 		return -ENOENT;
 	}
 
+#ifdef CONFIG_OF
+	for_each_compatible_node(np, NULL, "samsung,sdhci-s3c") {
+		const u32 *id = of_get_property(np, "cell-index", NULL);
+		if (be32_to_cpu(*id) == pdev->id)
+			break;
+	}
+
+	if (!np) {
+		dev_err(dev, "no matching device node specified in device tree\n");
+		return -ENOENT;
+	}
+#endif
+
+#ifndef CONFIG_OF
 	irq = platform_get_irq(pdev, 0);
+#else
+	irq = of_irq_to_resource(np, 0, NULL);
+#endif
 	if (irq < 0) {
 		dev_err(dev, "no irq specified\n");
 		return irq;
 	}
 
+#ifndef CONFIG_OF
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(dev, "no memory specified\n");
 		return -ENOENT;
 	}
+#else
+	if (of_address_to_resource(np, 0, &iores)) {
+		dev_err(dev, "no memory specified in device tree\n");
+		return -ENOENT;
+	}
+	res = &iores;
+#endif
 
 	host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c));
 	if (IS_ERR(host)) {
-- 
1.6.6.rc2