usb: dwc3: gadget: Set BESL config parameter

When operating with LPM signals, the controller asserts the deep
low-power signal (utmi_l1_suspend_n) to the phy when the BESL value of
the LPM token is equal to or greater than DCTL.HIRD_Thres[3:0] (and
with DCTL.HIRD_Thres[4] set). Otherwise, the shallow low-power signal
(utmi_sleep_n) is asserted. Set the recommended deep BESL equal to the
controller's DCTL.HIRD_Thres[3:0] setting, and set the baseline BESL
to 0 for the shallow low-power signal. This maximizes the opportunity
for L1 residency and optimizes power savings.

Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/gadget.c

@@ -2078,6 +2078,16 @@ static void dwc3_gadget_config_params(struct usb_gadget *g,
 {
 	struct dwc3		*dwc = gadget_to_dwc(g);
 
+	params->besl_baseline = USB_DEFAULT_BESL_UNSPECIFIED;
+	params->besl_deep = USB_DEFAULT_BESL_UNSPECIFIED;
+
+	/* Recommended BESL */
+	if (!dwc->dis_enblslpm_quirk) {
+		params->besl_baseline = 0;
+		if (dwc->is_utmi_l1_suspend)
+			params->besl_deep = min_t(u8, dwc->hird_threshold, 15);
+	}
+
 	/* U1 Device exit Latency */
 	if (dwc->dis_u1_entry_quirk)
 		params->bU1devExitLat = 0;