usb: dwc2: Add a quirk to allow speed negotiation for Hisilicon Hi6220

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.

Cc: Wei Xu <xuwei5@hisilicon.com>
Cc: Guodong Xu <guodong.xu@linaro.org>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: John Youn <johnyoun@synopsys.com>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Chen Yu <chenyu56@huawei.com>
Cc: Vardan Mikayelyan <mvardan@synopsys.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Chen Yu <chenyu56@huawei.com>
[jstultz: Reworked to simplify the patch, and made
 commit log to be more specific about the issue]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index b07bf7b..a473853 100644 (file)
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -444,6 +444,11 @@ enum dwc2_ep0_state {
  *                     in DWORDS with possible values from from
  *                     16-32768 (default: 256, 256, 256, 256, 768,
  *                     768, 768, 768, 0, 0, 0, 0, 0, 0, 0).
+ * @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
@@ -501,6 +506,8 @@ struct dwc2_core_params {
        u32 g_rx_fifo_size;
        u32 g_np_tx_fifo_size;
        u32 g_tx_fifo_size[MAX_EPS_CHANNELS];
+
+       bool change_speed_quirk;
 };
 
 /**

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 1f670c3..751f0dd 100644 (file)
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -4868,6 +4868,61 @@ static void _dwc2_hcd_clear_tt_buffer_complete(struct usb_hcd *hcd,
        spin_unlock_irqrestore(&hsotg->lock, flags);
 }
 
+/*
+ * HPRT0_SPD_HIGH_SPEED: high speed
+ * HPRT0_SPD_FULL_SPEED: full speed
+ */
+static void dwc2_change_bus_speed(struct usb_hcd *hcd, int speed)
+{
+       struct dwc2_hsotg *hsotg = dwc2_hcd_to_hsotg(hcd);
+
+       if (hsotg->params.speed == speed)
+               return;
+
+       hsotg->params.speed = speed;
+       queue_work(hsotg->wq_otg, &hsotg->wf_otg);
+}
+
+static void dwc2_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct dwc2_hsotg *hsotg = dwc2_hcd_to_hsotg(hcd);
+
+       if (!hsotg->params.change_speed_quirk)
+               return;
+
+       /*
+        * On removal, set speed to default high-speed.
+        */
+       if (udev->parent && udev->parent->speed > USB_SPEED_UNKNOWN &&
+           udev->parent->speed < USB_SPEED_HIGH) {
+               dev_info(hsotg->dev, "Set speed to default high-speed\n");
+               dwc2_change_bus_speed(hcd, HPRT0_SPD_HIGH_SPEED);
+       }
+}
+
+static int dwc2_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct dwc2_hsotg *hsotg = dwc2_hcd_to_hsotg(hcd);
+
+       if (!hsotg->params.change_speed_quirk)
+               return 0;
+
+       if (udev->speed == USB_SPEED_HIGH) {
+               dev_info(hsotg->dev, "Set speed to high-speed\n");
+               dwc2_change_bus_speed(hcd, HPRT0_SPD_HIGH_SPEED);
+       } else if ((udev->speed == USB_SPEED_FULL ||
+                               udev->speed == USB_SPEED_LOW)) {
+               /*
+                * Change speed setting to full-speed if there's
+                * a full-speed or low-speed device plugged in.
+                */
+               dev_info(hsotg->dev, "Set speed to full-speed\n");
+               dwc2_change_bus_speed(hcd, HPRT0_SPD_FULL_SPEED);
+       }
+
+       return 0;
+}
+
 static struct hc_driver dwc2_hc_driver = {
        .description = "dwc2_hsotg",
        .product_desc = "DWC OTG Controller",
@@ -5023,6 +5078,11 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg, int irq)
                        dev_warn(hsotg->dev, "can't set coherent DMA mask\n");
        }
 
+       if (hsotg->params.change_speed_quirk) {
+               dwc2_hc_driver.free_dev = dwc2_free_dev;
+               dwc2_hc_driver.reset_device = dwc2_reset_device;
+       }
+
        hcd = usb_create_hcd(&dwc2_hc_driver, hsotg->dev, dev_name(hsotg->dev));
        if (!hcd)
                goto error1;

diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c
index 620b027..8e5039e 100644 (file)
--- a/drivers/usb/dwc2/params.c
+++ b/drivers/usb/dwc2/params.c
@@ -68,6 +68,7 @@ static void dwc2_set_his_params(struct dwc2_hsotg *hsotg)
        p->ahbcfg = GAHBCFG_HBSTLEN_INCR16 <<
                GAHBCFG_HBSTLEN_SHIFT;
        p->uframe_sched = false;
+       p->change_speed_quirk = true;
 }
 
 static void dwc2_set_rk_params(struct dwc2_hsotg *hsotg)