ARM: Orion: SDIO: Add support for clk.

Some orion devices can gate the SDIO clock. If the clock exists,
enable/disable it as appropriate.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Jamie Lentin <jm@lentin.co.uk>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

arch/arm/mach-kirkwood/common.c

@@ -86,7 +86,7 @@ static struct clk __init *kirkwood_register_gate(const char *name, u8 bit_idx)
 
 void __init kirkwood_clk_init(void)
 {
-	struct clk *runit, *ge0, *ge1, *sata0, *sata1, *usb0;
+	struct clk *runit, *ge0, *ge1, *sata0, *sata1, *usb0, *sdio;
 
 	tclk = clk_register_fixed_rate(NULL, "tclk", NULL,
 				       CLK_IS_ROOT, kirkwood_tclk);
@@ -97,7 +97,7 @@ void __init kirkwood_clk_init(void)
 	sata0 = kirkwood_register_gate("sata0",  CGC_BIT_SATA0);
 	sata1 = kirkwood_register_gate("sata1",  CGC_BIT_SATA1);
 	usb0 = kirkwood_register_gate("usb0",   CGC_BIT_USB0);
-	kirkwood_register_gate("sdio",   CGC_BIT_SDIO);
+	sdio = kirkwood_register_gate("sdio",   CGC_BIT_SDIO);
 	kirkwood_register_gate("crypto", CGC_BIT_CRYPTO);
 	kirkwood_register_gate("xor0",   CGC_BIT_XOR0);
 	kirkwood_register_gate("xor1",   CGC_BIT_XOR1);
@@ -117,6 +117,7 @@ void __init kirkwood_clk_init(void)
 	orion_clkdev_add("1", "sata_mv.0", sata1);
 	orion_clkdev_add(NULL, "orion-ehci.0", usb0);
 	orion_clkdev_add(NULL, "orion_nand", runit);
+	orion_clkdev_add(NULL, "mvsdio", sdio);
 }
 
 /*****************************************************************************

drivers/mmc/host/mvsdio.c

@@ -19,6 +19,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/scatterlist.h>
 #include <linux/irq.h>
+#include <linux/clk.h>
 #include <linux/gpio.h>
 #include <linux/mmc/host.h>
 
@@ -51,6 +52,7 @@ struct mvsd_host {
 	struct device *dev;
 	struct resource *res;
 	int irq;
+	struct clk *clk;
 	int gpio_card_detect;
 	int gpio_write_protect;
 };
@@ -770,6 +772,13 @@ static int __init mvsd_probe(struct platform_device *pdev)
 	} else
 		host->irq = irq;
 
+	/* Not all platforms can gate the clock, so it is not
+	   an error if the clock does not exists. */
+	host->clk = clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(host->clk)) {
+		clk_prepare_enable(host->clk);
+	}
+
 	if (mvsd_data->gpio_card_detect) {
 		ret = gpio_request(mvsd_data->gpio_card_detect,
 				   DRIVER_NAME " cd");
@@ -854,6 +863,11 @@ static int __exit mvsd_remove(struct platform_device *pdev)
 		mvsd_power_down(host);
 		iounmap(host->base);
 		release_resource(host->res);
+
+		if (!IS_ERR(host->clk)) {
+			clk_disable_unprepare(host->clk);
+			clk_put(host->clk);
+		}
 		mmc_free_host(mmc);
 	}
 	platform_set_drvdata(pdev, NULL);