usb: dwc3: Add maximum hw supported speed flag

Maximum hardware supported speed flag limits the maximum speed
of the usb controller to high or super. Adding this additional
flag as maximum_speed flag can be changed from different sources
such as power delivery stack.

Change-Id: I18f414e822b5525fe848a48384fac102cdae7b03
Signed-off-by: Vamsi Krishna Samavedam <vskrishn@codeaurora.org>

3 files changed, 14 insertions, 4 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 5aae319198fa..76d966ca57ad 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -659,8 +659,10 @@ int dwc3_core_init(struct dwc3 *dwc)
 	/* Handle USB2.0-only core configuration */
 	if (DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3) ==
 			DWC3_GHWPARAMS3_SSPHY_IFC_DIS) {
-		if (dwc->maximum_speed == USB_SPEED_SUPER)
-			dwc->maximum_speed = USB_SPEED_HIGH;
+		if (dwc->max_hw_supp_speed == USB_SPEED_SUPER) {
+			dwc->max_hw_supp_speed = USB_SPEED_HIGH;
+			dwc->maximum_speed = dwc->max_hw_supp_speed;
+		}
 	}
 
 	ret = dwc3_core_reset(dwc);
@@ -1084,6 +1086,7 @@ static int dwc3_probe(struct platform_device *pdev)
 	hird_threshold = 12;
 
 	dwc->maximum_speed = usb_get_maximum_speed(dev);
+	dwc->max_hw_supp_speed = dwc->maximum_speed;
 	dwc->dr_mode = usb_get_dr_mode(dev);
 
 	dwc->has_lpm_erratum = device_property_read_bool(dev,
@@ -1157,6 +1160,7 @@ static int dwc3_probe(struct platform_device *pdev)
 
 	if (pdata) {
 		dwc->maximum_speed = pdata->maximum_speed;
+		dwc->max_hw_supp_speed = dwc->maximum_speed;
 		dwc->has_lpm_erratum = pdata->has_lpm_erratum;
 		if (pdata->lpm_nyet_threshold)
 			lpm_nyet_threshold = pdata->lpm_nyet_threshold;
@@ -1190,7 +1194,7 @@ static int dwc3_probe(struct platform_device *pdev)
 
 	/* default to superspeed if no maximum_speed passed */
 	if (dwc->maximum_speed == USB_SPEED_UNKNOWN)
-		dwc->maximum_speed = USB_SPEED_SUPER;
+		dwc->max_hw_supp_speed = dwc->maximum_speed = USB_SPEED_SUPER;
 
 	dwc->lpm_nyet_threshold = lpm_nyet_threshold;
 	dwc->tx_de_emphasis = tx_de_emphasis;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index c2cdfd1a823b..1abd827beb3f 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -757,7 +757,8 @@ struct dwc3_scratchpad_array {
  * @nr_scratch: number of scratch buffers
  * @num_event_buffers: calculated number of event buffers
  * @u1u2: only used on revisions <1.83a for workaround
- * @maximum_speed: maximum speed requested (mainly for testing purposes)
+ * @maximum_speed: maximum speed to operate as requested by sw
+ * @max_hw_supp_speed: maximum speed supported by hw design
  * @revision: revision register contents
  * @dr_mode: requested mode of operation
  * @usb2_phy: pointer to USB2 PHY
@@ -888,6 +889,7 @@ struct dwc3 {
 	u32			u1;
 	u32			u1u2;
 	u32			maximum_speed;
+	u32			max_hw_supp_speed;
 
 	/*
 	 * All 3.1 IP version constants are greater than the 3.0 IP
diff --git a/drivers/usb/dwc3/dwc3-msm.c b/drivers/usb/dwc3/dwc3-msm.c
index 1e252febc783..e3848b885b95 100644
--- a/drivers/usb/dwc3/dwc3-msm.c
+++ b/drivers/usb/dwc3/dwc3-msm.c
@@ -2608,6 +2608,8 @@ static int dwc3_msm_id_notifier(struct notifier_block *nb,
 
 	speed = extcon_get_cable_state_(edev, EXTCON_USB_SPEED);
 	dwc->maximum_speed = (speed <= 0) ? USB_SPEED_HIGH : USB_SPEED_SUPER;
+	if (dwc->maximum_speed > dwc->max_hw_supp_speed)
+		dwc->maximum_speed = dwc->max_hw_supp_speed;
 
 	if (mdwc->id_state != id) {
 		mdwc->id_state = id;
@@ -2649,6 +2651,8 @@ static int dwc3_msm_vbus_notifier(struct notifier_block *nb,
 
 	speed = extcon_get_cable_state_(edev, EXTCON_USB_SPEED);
 	dwc->maximum_speed = (speed <= 0) ? USB_SPEED_HIGH : USB_SPEED_SUPER;
+	if (dwc->maximum_speed > dwc->max_hw_supp_speed)
+		dwc->maximum_speed = dwc->max_hw_supp_speed;
 
 	mdwc->vbus_active = event;
 	if (dwc->is_drd && !mdwc->in_restart) {