dwc2 fixes for HiKey

I wanted to send out two patches we're using on the dwc2 driver in order to make HiKey function.

The first is seemingly just a bug fix we ran into when changing modes while the bus was auto-suspended.

The second is a little more interesting as it works around a limitation of the the device in that it can't handle split transactions, so the usb speed but be lowered and raised manually when full-speed devices come and go.

I wanted to send these out for further review and consideration.

Changes in v2:
* Fix build issue reported by kbuildbot
* Rework to avoid using new dts entry suggested by RobH
* Further tweaks from Chen Yu to try to address comments from John Youn
* Further simplified logic

Feedback would be greatly appreciated!

thanks
-john

Chen Yu (2):
usb: dwc2: Force port resume on switching to device mode
usb: dwc2: Add a quirk to allow speed negotiation for Hisilicon Hi6220

 drivers/usb/dwc2/core.h     |  6 ++++
 drivers/usb/dwc2/hcd.c      | 69 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/usb/dwc2/platform.c |  1 +
 3 files changed, 76 insertions(+)

2.7.4

From: Chen Yu <[email protected]>

We've seen failures when switching between host and gadget mode, which was diagnosed as being caused due to the bus being auto-suspended when we switched.

So this patch forces a port resume when switching to device mode if the bus is suspended.

---
 drivers/usb/dwc2/hcd.c | 8 ++++++++
 1 file changed, 8 insertions(+)

index df5a065..b374e60 100644
@@ -54,6 +54,9 @@
 #include "core.h"
 #include "hcd.h"
 
+
+static void dwc2_port_resume(struct dwc2_hsotg *hsotg);
+
 /*
  * =========================================================================
  *  Host Core Layer Functions

@@ -3204,6 +3207,11 @@ static void dwc2_conn_id_status_change(struct work_struct *work)
 	if (gotgctl & GOTGCTL_CONID_B) {
 		/* Wait for switch to device mode */
 		dev_dbg(hsotg->dev, "connId B\n");
+		if (hsotg->bus_suspended) {
+			dev_info(hsotg->dev,
+				"Do port resume before switching to device mode\n");
+			dwc2_port_resume(hsotg);
+		}
 		while (!dwc2_is_device_mode(hsotg)) {
 			dev_info(hsotg->dev,
 				 "Waiting for Peripheral Mode, Mode=%s\n",

2.7.4

From: Chen Yu <[email protected]>

The Hi6220's usb controller is limited in that it does not support "Split Transactions", so it does not support communicating with low-speed and full-speed devices behind a high-speed hub.

Thus it requires a quirk so that we can manually drop the usb speed when low/full-speed are attached, and bump back to high speed when they are removed.

[jstultz: Reworked to simplify the patch, and made
commit log to be more specific about the issue]

---
v2:
* Fix build issue reported by kbuildbot
* Rework to avoid using new dts entry suggested by RobH
* Further tweaks from Chen Yu to try to address comments from John Youn
* Further simplified logic

---
 drivers/usb/dwc2/core.h     |  6 +++++
 drivers/usb/dwc2/hcd.c      | 61 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/usb/dwc2/platform.c |  1 +
 3 files changed, 68 insertions(+)

index 2a21a04..baa4f64 100644
@@ -417,6 +417,11 @@ enum dwc2_ep0_state {
  *			needed.
  *			0 - No (default)
  *			1 - Yes
+ * @change_speed_quirk: Change speed configuration to DWC2_SPEED_PARAM_FULL
+ *                      while full&low speed device connect. And change speed
+ *                      back to DWC2_SPEED_PARAM_HIGH while device is gone.
+ *			0 - No (default)
+ *			1 - Yes
  *
  * The following parameters may be specified when starting the module. These
  * parameters define how the DWC_otg controller should be configured. A

@@ -457,6 +462,7 @@ struct dwc2_core_params {
 	int uframe_sched;
 	int external_id_pin_ctl;
 	int hibernation;
+	int change_speed_quirk;
 };
 
 /**

index 8e1728b..17eb5fd 100644
@@ -85,6 +85,7 @@ static const struct dwc2_core_params params_hi6220 = {
 	.uframe_sched			= 0,
 	.external_id_pin_ctl		= -1,
 	.hibernation			= -1,
+	.change_speed_quirk		= 1,
 };
 
 static const struct dwc2_core_params params_bcm2835 = {

2.7.4