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.html

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
index d443fbd8535b..c8e360d7d975 100644
--- a/drivers/usb/host/ehci-mxc.c
+++ b/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: