3 files changed, 39 insertions, 2 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 0104a80b185e..643239d7d370 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -26,6 +26,7 @@
 #include <linux/acpi.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/reset.h>
+#include <linux/bitfield.h>
 
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
@@ -336,6 +337,29 @@ static void dwc3_frame_length_adjustment(struct dwc3 *dwc)
 }
 
 /**
+ * dwc3_ref_clk_period - Reference clock period configuration
+ *		Default reference clock period depends on hardware
+ *		configuration. For systems with reference clock that differs
+ *		from the default, this will set clock period in DWC3_GUCTL
+ *		register.
+ * @dwc: Pointer to our controller context structure
+ * @ref_clk_per: reference clock period in ns
+ */
+static void dwc3_ref_clk_period(struct dwc3 *dwc)
+{
+	u32 reg;
+
+	if (dwc->ref_clk_per == 0)
+		return;
+
+	reg = dwc3_readl(dwc->regs, DWC3_GUCTL);
+	reg &= ~DWC3_GUCTL_REFCLKPER_MASK;
+	reg |=  FIELD_PREP(DWC3_GUCTL_REFCLKPER_MASK, dwc->ref_clk_per);
+	dwc3_writel(dwc->regs, DWC3_GUCTL, reg);
+}
+
+
+/**
  * dwc3_free_one_event_buffer - Frees one event buffer
  * @dwc: Pointer to our controller context structure
  * @evt: Pointer to event buffer to be freed
@@ -1007,6 +1031,9 @@ static int dwc3_core_init(struct dwc3 *dwc)
 	/* Adjust Frame Length */
 	dwc3_frame_length_adjustment(dwc);
 
+	/* Adjust Reference Clock Period */
+	dwc3_ref_clk_period(dwc);
+
 	dwc3_set_incr_burst_type(dwc);
 
 	usb_phy_set_suspend(dwc->usb2_phy, 0);
@@ -1389,6 +1416,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 				    &dwc->hsphy_interface);
 	device_property_read_u32(dev, "snps,quirk-frame-length-adjustment",
 				 &dwc->fladj);
+	device_property_read_u32(dev, "snps,ref-clock-period-ns",
+				 &dwc->ref_clk_per);
 
 	dwc->dis_metastability_quirk = device_property_read_bool(dev,
 				"snps,dis_metastability_quirk");
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 5612bfdf37da..ee854697c300 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -387,6 +387,10 @@
 #define DWC3_GFLADJ_30MHZ_SDBND_SEL		BIT(7)
 #define DWC3_GFLADJ_30MHZ_MASK			0x3f
 
+/* Global User Control Register*/
+#define DWC3_GUCTL_REFCLKPER_MASK		0xffc00000
+#define DWC3_GUCTL_REFCLKPER_SEL		22
+
 /* Global User Control Register 2 */
 #define DWC3_GUCTL2_RST_ACTBITLATER		BIT(14)
 
@@ -970,6 +974,7 @@ struct dwc3_scratchpad_array {
  * @regs: base address for our registers
  * @regs_size: address space size
  * @fladj: frame length adjustment
+ * @ref_clk_per: reference clock period configuration
  * @irq_gadget: peripheral controller's IRQ number
  * @otg_irq: IRQ number for OTG IRQs
  * @current_otg_role: current role of operation while using the OTG block
@@ -1027,6 +1032,7 @@ struct dwc3_scratchpad_array {
  * @tx_fifo_resize_max_num: max number of fifos allocated during txfifo resize
  * @hsphy_interface: "utmi" or "ulpi"
  * @connected: true when we're connected to a host, false otherwise
+ * @softconnect: true when gadget connect is called, false when disconnect runs
  * @delayed_status: true when gadget driver asks for delayed status
  * @ep0_bounced: true when we used bounce buffer
  * @ep0_expect_in: true when we expect a DATA IN transfer
@@ -1149,6 +1155,7 @@ struct dwc3 {
 	struct power_supply	*usb_psy;
 
 	u32			fladj;
+	u32			ref_clk_per;
 	u32			irq_gadget;
 	u32			otg_irq;
 	u32			current_otg_role;
@@ -1246,6 +1253,7 @@ struct dwc3 {
 	const char		*hsphy_interface;
 
 	unsigned		connected:1;
+	unsigned		softconnect:1;
 	unsigned		delayed_status:1;
 	unsigned		ep0_bounced:1;
 	unsigned		ep0_expect_in:1;
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 804b50548163..32e01885b211 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2418,7 +2418,7 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 	int			ret;
 
 	is_on = !!is_on;
-
+	dwc->softconnect = is_on;
 	/*
 	 * Per databook, when we want to stop the gadget, if a control transfer
 	 * is still in process, complete it and get the core into setup phase.
@@ -4352,7 +4352,7 @@ int dwc3_gadget_resume(struct dwc3 *dwc)
 {
 	int			ret;
 
-	if (!dwc->gadget_driver)
+	if (!dwc->gadget_driver || !dwc->softconnect)
 		return 0;
 
 	ret = __dwc3_gadget_start(dwc);