mmc: mmci: Enable Device Tree support for ux500 variants

Provide a means to collect attributes specific to ST-Ericsson's ux500
variant series. This patch registers itself as the AMBA driver to be
called during the probe process. Once all attributes and ux500 specifics
are are collected the normal mmci core probe is called.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/mmci.c

@@ -15,6 +15,7 @@
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/highmem.h>
@@ -1196,21 +1197,70 @@ static const struct mmc_host_ops mmci_ops = {
 	.get_cd		= mmci_get_cd,
 };
 
+#ifdef CONFIG_OF
+static void mmci_dt_populate_generic_pdata(struct device_node *np,
+					struct mmci_platform_data *pdata)
+{
+	int bus_width = 0;
+
+	of_property_read_u32(np, "wp-gpios", &pdata->gpio_wp);
+	if (!pdata->gpio_wp)
+		pdata->gpio_wp = -1;
+
+	of_property_read_u32(np, "cd-gpios", &pdata->gpio_cd);
+	if (!pdata->gpio_cd)
+		pdata->gpio_cd = -1;
+
+	if (of_get_property(np, "cd-inverted", NULL))
+		pdata->cd_invert = true;
+	else
+		pdata->cd_invert = false;
+
+	of_property_read_u32(np, "max-frequency", &pdata->f_max);
+	if (!pdata->f_max)
+		pr_warn("%s has no 'max-frequency' property\n", np->full_name);
+
+	if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
+		pdata->capabilities |= MMC_CAP_MMC_HIGHSPEED;
+	if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
+		pdata->capabilities |= MMC_CAP_SD_HIGHSPEED;
+
+	of_property_read_u32(np, "bus-width", &bus_width);
+	switch (bus_width) {
+	case 0 :
+		/* No bus-width supplied. */
+		break;
+	case 4 :
+		pdata->capabilities |= MMC_CAP_4_BIT_DATA;
+		break;
+	case 8 :
+		pdata->capabilities |= MMC_CAP_8_BIT_DATA;
+		break;
+	default :
+		pr_warn("%s: Unsupported bus width\n", np->full_name);
+	}
+}
+#endif
+
 static int __devinit mmci_probe(struct amba_device *dev,
 	const struct amba_id *id)
 {
 	struct mmci_platform_data *plat = dev->dev.platform_data;
+	struct device_node *np = dev->dev.of_node;
 	struct variant_data *variant = id->data;
 	struct mmci_host *host;
 	struct mmc_host *mmc;
 	int ret;
 
-	/* must have platform data */
-	if (!plat) {
-		ret = -EINVAL;
-		goto out;
+	/* Must have platform data or Device Tree. */
+	if (!plat && !np) {
+		dev_err(&dev->dev, "No plat data or DT found\n");
+		return -EINVAL;
 	}
 
+	if (np)
+		mmci_dt_populate_generic_pdata(np, plat);
+
 	ret = amba_request_regions(dev, DRIVER_NAME);
 	if (ret)
 		goto out;