Merge remote-tracking branch 'usb-gadget/next'

[deliverable/linux.git] / drivers / usb / dwc2 / core.c

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index 4135a5ff67ca75257583d14ebda6a1737fa5066f..fa9b26b915071ada49ee1b068ff098c09a962ff1 100644 (file)
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -238,6 +238,77 @@ int dwc2_enter_hibernation(struct dwc2_hsotg *hsotg)
        return ret;
 }
 
+/**
+ * dwc2_wait_for_mode() - Waits for the controller mode.
+ * @hsotg:     Programming view of the DWC_otg controller.
+ * @host_mode: If true, waits for host mode, otherwise device mode.
+ */
+static void dwc2_wait_for_mode(struct dwc2_hsotg *hsotg,
+                              bool host_mode)
+{
+       ktime_t start;
+       ktime_t end;
+       unsigned int timeout = 110;
+
+       dev_vdbg(hsotg->dev, "Waiting for %s mode\n",
+                host_mode ? "host" : "device");
+
+       start = ktime_get();
+
+       while (1) {
+               s64 ms;
+
+               if (dwc2_is_host_mode(hsotg) == host_mode) {
+                       dev_vdbg(hsotg->dev, "%s mode set\n",
+                                host_mode ? "Host" : "Device");
+                       break;
+               }
+
+               end = ktime_get();
+               ms = ktime_to_ms(ktime_sub(end, start));
+
+               if (ms >= (s64)timeout) {
+                       dev_warn(hsotg->dev, "%s: Couldn't set %s mode\n",
+                                __func__, host_mode ? "host" : "device");
+                       break;
+               }
+
+               usleep_range(1000, 2000);
+       }
+}
+
+/**
+ * dwc2_iddig_filter_enabled() - Returns true if the IDDIG debounce
+ * filter is enabled.
+ */
+static bool dwc2_iddig_filter_enabled(struct dwc2_hsotg *hsotg)
+{
+       u32 gsnpsid;
+       u32 ghwcfg4;
+
+       if (!dwc2_hw_is_otg(hsotg))
+               return false;
+
+       /* Check if core configuration includes the IDDIG filter. */
+       ghwcfg4 = dwc2_readl(hsotg->regs + GHWCFG4);
+       if (!(ghwcfg4 & GHWCFG4_IDDIG_FILT_EN))
+               return false;
+
+       /*
+        * Check if the IDDIG debounce filter is bypassed. Available
+        * in core version >= 3.10a.
+        */
+       gsnpsid = dwc2_readl(hsotg->regs + GSNPSID);
+       if (gsnpsid >= DWC2_CORE_REV_3_10a) {
+               u32 gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
+
+               if (gotgctl & GOTGCTL_DBNCE_FLTR_BYPASS)
+                       return false;
+       }
+
+       return true;
+}
+
 /*
  * Do core a soft reset of the core.  Be careful with this because it
  * resets all the internal state machines of the core.
@@ -246,9 +317,30 @@ int dwc2_core_reset(struct dwc2_hsotg *hsotg)
 {
        u32 greset;
        int count = 0;
+       bool wait_for_host_mode = false;
 
        dev_vdbg(hsotg->dev, "%s()\n", __func__);
 
+       /*
+        * If the current mode is host, either due to the force mode
+        * bit being set (which persists after core reset) or the
+        * connector id pin, a core soft reset will temporarily reset
+        * the mode to device. A delay from the IDDIG debounce filter
+        * will occur before going back to host mode.
+        *
+        * Determine whether we will go back into host mode after a
+        * reset and account for this delay after the reset.
+        */
+       if (dwc2_iddig_filter_enabled(hsotg)) {
+               u32 gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
+               u32 gusbcfg = dwc2_readl(hsotg->regs + GUSBCFG);
+
+               if (!(gotgctl & GOTGCTL_CONID_B) ||
+                   (gusbcfg & GUSBCFG_FORCEHOSTMODE)) {
+                       wait_for_host_mode = true;
+               }
+       }
+
        /* Core Soft Reset */
        greset = dwc2_readl(hsotg->regs + GRSTCTL);
        greset |= GRSTCTL_CSFTRST;
@@ -277,6 +369,9 @@ int dwc2_core_reset(struct dwc2_hsotg *hsotg)
                }
        } while (!(greset & GRSTCTL_AHBIDLE));
 
+       if (wait_for_host_mode)
+               dwc2_wait_for_mode(hsotg, true);
+
        return 0;
 }
 
@@ -300,9 +395,9 @@ int dwc2_core_reset(struct dwc2_hsotg *hsotg)
  * Checks are done in this function to determine whether doing a force
  * would be valid or not.
  *
- * If a force is done, it requires a 25ms delay to take effect.
- *
- * Returns true if the mode was forced.
+ * If a force is done, it requires a IDDIG debounce filter delay if
+ * the filter is configured and enabled. We poll the current mode of
+ * the controller to account for this delay.
  */
 static bool dwc2_force_mode(struct dwc2_hsotg *hsotg, bool host)
 {
@@ -337,12 +432,18 @@ static bool dwc2_force_mode(struct dwc2_hsotg *hsotg, bool host)
        gusbcfg |= set;
        dwc2_writel(gusbcfg, hsotg->regs + GUSBCFG);
 
-       msleep(25);
+       dwc2_wait_for_mode(hsotg, host);
        return true;
 }
 
-/*
- * Clears the force mode bits.
+/**
+ * dwc2_clear_force_mode() - Clears the force mode bits.
+ *
+ * After clearing the bits, wait up to 100 ms to account for any
+ * potential IDDIG filter delay. We can't know if we expect this delay
+ * or not because the value of the connector ID status is affected by
+ * the force mode. We only need to call this once during probe if
+ * dr_mode == OTG.
  */
 static void dwc2_clear_force_mode(struct dwc2_hsotg *hsotg)
 {
@@ -353,11 +454,8 @@ static void dwc2_clear_force_mode(struct dwc2_hsotg *hsotg)
        gusbcfg &= ~GUSBCFG_FORCEDEVMODE;
        dwc2_writel(gusbcfg, hsotg->regs + GUSBCFG);
 
-       /*
-        * NOTE: This long sleep is _very_ important, otherwise the core will
-        * not stay in host mode after a connector ID change!
-        */
-       msleep(25);
+       if (dwc2_iddig_filter_enabled(hsotg))
+               usleep_range(100000, 110000);
 }
 
 /*
@@ -380,12 +478,6 @@ void dwc2_force_dr_mode(struct dwc2_hsotg *hsotg)
                         __func__, hsotg->dr_mode);
                break;
        }
-
-       /*
-        * NOTE: This is required for some rockchip soc based
-        * platforms.
-        */
-       msleep(50);
 }
 
 /*