ENGR00162583-1 usb msl: avoid class driver access register after usb is off

- An well-behavior class driver should disable their endpoints
after being notified disconnect with host, we use all endpoints
are stopped (ep->stopped)  to indicates the class
driver will not visit device driver any more.
the ep-stopped will be initialized as 1 for non-control endpoint
it will be 0 after fsl_ep_enable, and be 1 after fsl_ep_disable.
Where is a non-sleep wait routine at disconnect event for waiting all
endpoints are stopped
- Some controller's (like i.mx6q) DP will change from J
to SE0 slowly after the cable disconnects with host, in that case there
will be a wakeup interrupt after driver enables the wakeup interrupt.
For i.mx6q, there is a discharge routine for DP after the disconnection.
- Should not wait vbus to low during first otg switch, as the wait will
be timeout when the usb cable is connecting to host.

Signed-off-by: Peter Chen <peter.chen@freescale.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/arm/mach-mx6/usb_dr.c b/arch/arm/mach-mx6/usb_dr.c
index de84a4ded23b..957b021e0a73 100644
--- a/arch/arm/mach-mx6/usb_dr.c
+++ b/arch/arm/mach-mx6/usb_dr.c
@@ -365,6 +365,19 @@ static void host_wakeup_handler(struct fsl_usb2_platform_data *pdata)
 
 #ifdef CONFIG_USB_GADGET_ARC
 /* Beginning of device related operation for DR port */
+static void _gadget_discharge_dp(bool enable)
+{
+	void __iomem *phy_reg = MX6_IO_ADDRESS(USB_PHY0_BASE_ADDR);
+	if (enable) {
+		__raw_writel(BF_USBPHY_DEBUG_ENHSTPULLDOWN(0x2), phy_reg + HW_USBPHY_DEBUG_SET);
+		__raw_writel(BF_USBPHY_DEBUG_HSTPULLDOWN(0x2), phy_reg + HW_USBPHY_DEBUG_SET);
+	} else {
+		__raw_writel(BF_USBPHY_DEBUG_ENHSTPULLDOWN(0x2), phy_reg + HW_USBPHY_DEBUG_CLR);
+		__raw_writel(BF_USBPHY_DEBUG_HSTPULLDOWN(0x2), phy_reg + HW_USBPHY_DEBUG_CLR);
+	}
+
+}
+
 static void _device_phy_lowpower_suspend(struct fsl_usb2_platform_data *pdata, bool enable)
 {
 	__phy_lowpower_suspend(pdata, enable, ENABLED_BY_DEVICE);
@@ -450,6 +463,7 @@ void __init mx6_usb_dr_init(void)
 	dr_utmi_config.wake_up_enable = _device_wakeup_enable;
 	dr_utmi_config.phy_lowpower_suspend = _device_phy_lowpower_suspend;
 	dr_utmi_config.is_wakeup_event = _is_device_wakeup;
+	dr_utmi_config.gadget_discharge_dp = _gadget_discharge_dp;
 	dr_utmi_config.wakeup_pdata = &dr_wakeup_config;
 	dr_utmi_config.wakeup_handler = device_wakeup_handler;
 	pdev = imx6q_add_fsl_usb2_udc(&dr_utmi_config);