dwc3: gadget: reinitialize core after each role change

According to the Databook in case of reconnection and role switching
the core should be completely reinitialized, excepting first connection
as peripheral when core was initialized during probing.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 399a33d..6ab2096 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1422,13 +1422,120 @@ static int dwc3_gadget_set_selfpowered(struct usb_gadget *g,
        return 0;
 }
 
+static int dwc3_udc_init(struct dwc3 *dwc)
+{
+       struct dwc3_ep          *dep;
+       int                     ret = 0;
+       u32                     reg;
+
+       reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+       reg &= ~(DWC3_DCFG_SPEED_MASK);
+
+       /**
+        * WORKAROUND: DWC3 revision < 2.20a have an issue
+        * which would cause metastability state on Run/Stop
+        * bit if we try to force the IP to USB2-only mode.
+        *
+        * Because of that, we cannot configure the IP to any
+        * speed other than the SuperSpeed
+        *
+        * Refers to:
+        *
+        * STAR#9000525659: Clock Domain Crossing on DCTL in
+        * USB 2.0 Mode
+        */
+       if (dwc->revision < DWC3_REVISION_220A) {
+               reg |= DWC3_DCFG_SUPERSPEED;
+       } else {
+               switch (dwc->maximum_speed) {
+               case USB_SPEED_LOW:
+                       reg |= DWC3_DSTS_LOWSPEED;
+                       break;
+               case USB_SPEED_FULL:
+                       reg |= DWC3_DSTS_FULLSPEED1;
+                       break;
+               case USB_SPEED_HIGH:
+                       reg |= DWC3_DSTS_HIGHSPEED;
+                       break;
+               case USB_SPEED_SUPER:   /* FALLTHROUGH */
+               case USB_SPEED_UNKNOWN: /* FALTHROUGH */
+               default:
+                       reg |= DWC3_DSTS_SUPERSPEED;
+               }
+       }
+       dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+
+       dwc->start_config_issued = false;
+
+       /* Start with SuperSpeed Default */
+       dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
+
+       dep = dwc->eps[0];
+       ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc,
+               NULL, false, false);
+       if (ret) {
+               dev_err(dwc->dev, "failed to enable %s\n", dep->name);
+               goto err0;
+       }
+
+       dep = dwc->eps[1];
+       ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc,
+               NULL, false, false);
+       if (ret) {
+               dev_err(dwc->dev, "failed to enable %s\n", dep->name);
+               goto err1;
+       }
+
+       /* begin to receive SETUP packets */
+       dwc->ep0state = EP0_SETUP_PHASE;
+       dwc3_ep0_out_start(dwc);
+
+       return 0;
+
+err1:
+       __dwc3_gadget_ep_disable(dwc->eps[0]);
+
+err0:
+       return ret;
+}
+
+static void dwc3_gadget_enable_irq(struct dwc3 *dwc);
+static void dwc3_gadget_disable_irq(struct dwc3 *dwc);
+
 static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
 {
        u32                     reg;
        u32                     timeout = 500;
+       int                     ret;
 
        reg = dwc3_readl(dwc->regs, DWC3_DCTL);
        if (is_on) {
+               /*
+                * According to the Databook in case of reconnection and
+                * role switching the core should be completely reinitialized.
+                * Exception: first connection as peripheral when core was
+                * initialized during probing.
+                */
+               if (dwc->needs_reinit) {
+                       ret = dwc3_core_init(dwc);
+                       if (ret) {
+                               dev_err(dwc->dev, "failed to reinitialize core\n");
+                               return ret;
+                       }
+
+                       dwc3_event_buffers_setup(dwc);
+               }
+
+               ret = dwc3_udc_init(dwc);
+               if (ret) {
+                       dev_err(dwc->dev, "failed to initialize udc\n");
+                       return ret;
+               }
+
+               dwc3_gadget_enable_irq(dwc);
+
+               dwc->needs_reinit = 0;
+
                if (dwc->revision <= DWC3_REVISION_187A) {
                        reg &= ~DWC3_DCTL_TRGTULST_MASK;
                        reg |= DWC3_DCTL_TRGTULST_RX_DET;
@@ -1443,6 +1550,10 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
 
                dwc->pullups_connected = true;
        } else {
+               dwc3_gadget_disable_irq(dwc);
+               __dwc3_gadget_ep_disable(dwc->eps[0]);
+               __dwc3_gadget_ep_disable(dwc->eps[1]);
+
                reg &= ~DWC3_DCTL_RUN_STOP;
 
                if (dwc->has_hibernation && !suspend)
@@ -1468,6 +1579,12 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
                udelay(1);
        } while (1);
 
+       if (!is_on) {
+               /* when everything is done, shutdown PHYs */
+               dwc3_core_exit(dwc);
+               dwc->needs_reinit = 1;
+       }
+
        dwc3_trace(trace_dwc3_gadget, "gadget %s data soft-%s",
                        dwc->gadget_driver
                        ? dwc->gadget_driver->function : "no-function",
@@ -1563,11 +1680,9 @@ static int dwc3_gadget_start(struct usb_gadget *g,
                struct usb_gadget_driver *driver)
 {
        struct dwc3             *dwc = gadget_to_dwc(g);
-       struct dwc3_ep          *dep;
        unsigned long           flags;
        int                     ret = 0;
        int                     irq;
-       u32                     reg;
 
        irq = platform_get_irq(to_platform_device(dwc->dev), 0);
        ret = request_threaded_irq(irq, dwc3_interrupt, dwc3_thread_interrupt,
@@ -1590,80 +1705,10 @@ static int dwc3_gadget_start(struct usb_gadget *g,
 
        dwc->gadget_driver      = driver;
 
-       reg = dwc3_readl(dwc->regs, DWC3_DCFG);
-       reg &= ~(DWC3_DCFG_SPEED_MASK);
-
-       /**
-        * WORKAROUND: DWC3 revision < 2.20a have an issue
-        * which would cause metastability state on Run/Stop
-        * bit if we try to force the IP to USB2-only mode.
-        *
-        * Because of that, we cannot configure the IP to any
-        * speed other than the SuperSpeed
-        *
-        * Refers to:
-        *
-        * STAR#9000525659: Clock Domain Crossing on DCTL in
-        * USB 2.0 Mode
-        */
-       if (dwc->revision < DWC3_REVISION_220A) {
-               reg |= DWC3_DCFG_SUPERSPEED;
-       } else {
-               switch (dwc->maximum_speed) {
-               case USB_SPEED_LOW:
-                       reg |= DWC3_DSTS_LOWSPEED;
-                       break;
-               case USB_SPEED_FULL:
-                       reg |= DWC3_DSTS_FULLSPEED1;
-                       break;
-               case USB_SPEED_HIGH:
-                       reg |= DWC3_DSTS_HIGHSPEED;
-                       break;
-               case USB_SPEED_SUPER:   /* FALLTHROUGH */
-               case USB_SPEED_UNKNOWN: /* FALTHROUGH */
-               default:
-                       reg |= DWC3_DSTS_SUPERSPEED;
-               }
-       }
-       dwc3_writel(dwc->regs, DWC3_DCFG, reg);
-
-       dwc->start_config_issued = false;
-
-       /* Start with SuperSpeed Default */
-       dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
-
-       dep = dwc->eps[0];
-       ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, false,
-                       false);
-       if (ret) {
-               dev_err(dwc->dev, "failed to enable %s\n", dep->name);
-               goto err2;
-       }
-
-       dep = dwc->eps[1];
-       ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, false,
-                       false);
-       if (ret) {
-               dev_err(dwc->dev, "failed to enable %s\n", dep->name);
-               goto err3;
-       }
-
-       /* begin to receive SETUP packets */
-       dwc->ep0state = EP0_SETUP_PHASE;
-       dwc3_ep0_out_start(dwc);
-
-       dwc3_gadget_enable_irq(dwc);
-
        spin_unlock_irqrestore(&dwc->lock, flags);
 
        return 0;
 
-err3:
-       __dwc3_gadget_ep_disable(dwc->eps[0]);
-
-err2:
-       dwc->gadget_driver = NULL;
-
 err1:
        spin_unlock_irqrestore(&dwc->lock, flags);