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>

diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
index d443fbd8535be8a779f75734d0dd63f45dd15546..c8e360d7d9759dbde4eff329781c252d5d27e806 100644 (file)
--- 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: