USB: ehci-mxc: add work-around for efika mx/sb bug

Add support for setting CHRGVBUS to workaround a hardware bug on efika mx/sb
boards.
See http://lists.infradead.org/pipermail/linux-arm-kernel/2011-January/037341.htmlSigned-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/ehci-mxc.c

@@ -21,10 +21,13 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/usb/otg.h>
+#include <linux/usb/ulpi.h>
 #include <linux/slab.h>
 
 #include <mach/mxc_ehci.h>
 
+#include <asm/mach-types.h>
+
 #define ULPI_VIEWPORT_OFFSET	0x170
 
 struct ehci_mxc_priv {
@@ -114,6 +117,7 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
 	struct usb_hcd *hcd;
 	struct resource *res;
 	int irq, ret;
+	unsigned int flags;
 	struct ehci_mxc_priv *priv;
 	struct device *dev = &pdev->dev;
 	struct ehci_hcd *ehci;
@@ -240,6 +244,23 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_add;
 
+	if (pdata->otg) {
+		/*
+		 * efikamx and efikasb have some hardware bug which is
+		 * preventing usb to work unless CHRGVBUS is set.
+		 * It's in violation of USB specs
+		 */
+		if (machine_is_mx51_efikamx() || machine_is_mx51_efikasb()) {
+			flags = otg_io_read(pdata->otg, ULPI_OTG_CTRL);
+			flags |= ULPI_OTG_CTRL_CHRGVBUS;
+			ret = otg_io_write(pdata->otg, flags, ULPI_OTG_CTRL);
+			if (ret) {
+				dev_err(dev, "unable to set CHRVBUS\n");
+				goto err_add;
+			}
+		}
+	}
+
 	return 0;
 
 err_add: