arm: i.MX/MX1 SDHC implements SD cards read-only switch read-back

The patch enables to define MMC host get_ro() method through platform data.
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

arch/arm/mach-imx/mx1ads.c

@@ -116,7 +116,7 @@ static struct platform_device *devices[] __initdata = {
 };
 
 #ifdef CONFIG_MMC_IMX
-static int mx1ads_mmc_card_present(void)
+static int mx1ads_mmc_card_present(struct device *dev)
 {
 	/* MMC/SD Card Detect is PB 20 on MX1ADS V1.0.7 */
 	return (SSR(1) & (1 << 20) ? 0 : 1);

drivers/mmc/host/imxmmc.c

@@ -884,9 +884,21 @@ static void imxmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	}
 }
 
+static int imxmci_get_ro(struct mmc_host *mmc)
+{
+	struct imxmci_host *host = mmc_priv(mmc);
+
+	if (host->pdata && host->pdata->get_ro)
+		return host->pdata->get_ro(mmc_dev(mmc));
+	/* Host doesn't support read only detection so assume writeable */
+	return 0;
+}
+
+
 static const struct mmc_host_ops imxmci_ops = {
 	.request	= imxmci_request,
 	.set_ios	= imxmci_set_ios,
+	.get_ro		= imxmci_get_ro,
 };
 
 static struct resource *platform_device_resource(struct platform_device *dev, unsigned int mask, int nr)
@@ -913,7 +925,7 @@ static void imxmci_check_status(unsigned long data)
 {
 	struct imxmci_host *host = (struct imxmci_host *)data;
 
-	if( host->pdata->card_present() != host->present ) {
+	if( host->pdata->card_present(mmc_dev(host->mmc)) != host->present ) {
 		host->present ^= 1;
 		dev_info(mmc_dev(host->mmc), "card %s\n",
 		      host->present ? "inserted" : "removed");
@@ -1022,7 +1034,7 @@ static int imxmci_probe(struct platform_device *pdev)
 	if (ret)
 		goto out;
 
-	host->present = host->pdata->card_present();
+	host->present = host->pdata->card_present(mmc_dev(mmc));
 	init_timer(&host->timer);
 	host->timer.data = (unsigned long)host;
 	host->timer.function = imxmci_check_status;

include/asm-arm/arch-imx/mmc.h

@@ -3,8 +3,11 @@
 
 #include <linux/mmc/host.h>
 
+struct device;
+
 struct imxmmc_platform_data {
-	int (*card_present)(void);
+	int (*card_present)(struct device *);
+	int (*get_ro)(struct device *);
 };
 
 extern void imx_set_mmc_info(struct imxmmc_platform_data *info);