usb: dwc3: gadget: implement Global Command support

This will be used by the ep0 layer for implementing
Set SEL Standard Request.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/core.h

@@ -284,12 +284,14 @@
 #define DWC3_DGCMD_SET_ENDPOINT_NRDY	0x0c
 #define DWC3_DGCMD_RUN_SOC_BUS_LOOPBACK	0x10
 
+#define DWC3_DGCMD_STATUS(n)		(((n) >> 15) & 1)
+#define DWC3_DGCMD_CMDACT		(1 << 10)
+
 /* Device Endpoint Command Register */
 #define DWC3_DEPCMD_PARAM_SHIFT		16
 #define DWC3_DEPCMD_PARAM(x)		((x) << DWC3_DEPCMD_PARAM_SHIFT)
 #define DWC3_DEPCMD_GET_RSC_IDX(x)     (((x) >> DWC3_DEPCMD_PARAM_SHIFT) & 0x7f)
-#define DWC3_DEPCMD_STATUS_MASK		(0x0f << 12)
-#define DWC3_DEPCMD_STATUS(x)		(((x) & DWC3_DEPCMD_STATUS_MASK) >> 12)
+#define DWC3_DEPCMD_STATUS(x)		(((x) >> 15) & 1)
 #define DWC3_DEPCMD_HIPRI_FORCERM	(1 << 11)
 #define DWC3_DEPCMD_CMDACT		(1 << 10)
 #define DWC3_DEPCMD_CMDIOC		(1 << 8)

drivers/usb/dwc3/gadget.c

@@ -276,6 +276,33 @@ static const char *dwc3_gadget_ep_cmd_string(u8 cmd)
 	}
 }
 
+int dwc3_send_gadget_generic_command(struct dwc3 *dwc, int cmd, u32 param)
+{
+	u32		timeout = 500;
+	u32		reg;
+
+	dwc3_writel(dwc->regs, DWC3_DGCMDPAR, param);
+	dwc3_writel(dwc->regs, DWC3_DGCMD, cmd | DWC3_DGCMD_CMDACT);
+
+	do {
+		reg = dwc3_readl(dwc->regs, DWC3_DGCMD);
+		if (!(reg & DWC3_DGCMD_CMDACT)) {
+			dev_vdbg(dwc->dev, "Command Complete --> %d\n",
+					DWC3_DGCMD_STATUS(reg));
+			return 0;
+		}
+
+		/*
+		 * We can't sleep here, because it's also called from
+		 * interrupt context.
+		 */
+		timeout--;
+		if (!timeout)
+			return -ETIMEDOUT;
+		udelay(1);
+	} while (1);
+}
+
 int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
 		unsigned cmd, struct dwc3_gadget_ep_cmd_params *params)
 {

drivers/usb/dwc3/gadget.h

@@ -111,6 +111,7 @@ int dwc3_gadget_ep0_queue(struct usb_ep *ep, struct usb_request *request,
 int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value);
 int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
 		unsigned cmd, struct dwc3_gadget_ep_cmd_params *params);
+int dwc3_send_gadget_generic_command(struct dwc3 *dwc, int cmd, u32 param);
 
 /**
  * dwc3_gadget_ep_get_transfer_index - Gets transfer index from HW