[PATCH 5/5 v2] usb: dwc2: Add a quirk to allow speed negotiation for Hisilicon Hi6220

From: John Stultz
Date: Tue Jan 03 2017 - 14:54:13 EST


From: Chen Yu <chenyu56@xxxxxxxxxx>

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@xxxxxxxxxxxxx>
Cc: Guodong Xu <guodong.xu@xxxxxxxxxx>
Cc: Amit Pundir <amit.pundir@xxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: John Youn <johnyoun@xxxxxxxxxxxx>
Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
Cc: Chen Yu <chenyu56@xxxxxxxxxx>
Cc: Vardan Mikayelyan <mvardan@xxxxxxxxxxxx>
Cc: Kishon Vijay Abraham I <kishon@xxxxxx>
Cc: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Signed-off-by: Chen Yu <chenyu56@xxxxxxxxxx>
[jstultz: Reworked to simplify the patch, and made
commit log to be more specific about the issue]
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
v2:
* Reworked to adapt around changes that landed in 4.10-rc

drivers/usb/dwc2/core.h | 7 ++++++
drivers/usb/dwc2/hcd.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/usb/dwc2/params.c | 19 +++++++++++++++
3 files changed, 86 insertions(+)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index eb2d628..4074752 100644
--- 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
@@ -516,6 +521,8 @@ struct dwc2_core_params {
u16 g_rx_fifo_size;
u16 g_np_tx_fifo_size;
u32 g_tx_fifo_size[MAX_EPS_CHANNELS];
+
+ int change_speed_quirk;
};

/**
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 6e4ec8a..81997d2 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -4876,6 +4876,61 @@ 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",
@@ -5031,6 +5086,11 @@ 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 a786256..71ca9c2 100644
--- a/drivers/usb/dwc2/params.c
+++ b/drivers/usb/dwc2/params.c
@@ -67,6 +67,7 @@ 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 = {
@@ -227,6 +228,7 @@ static const struct dwc2_core_params params_default = {
.uframe_sched = -1,
.external_id_pin_ctl = -1,
.hibernation = -1,
+ .change_speed_quirk = -1,
};

const struct of_device_id dwc2_of_match_table[] = {
@@ -1110,6 +1112,22 @@ static void dwc2_set_gadget_dma(struct dwc2_hsotg *hsotg)
!!hw->dma_desc_enable);
}

+static void dwc2_set_change_speed_quirk(struct dwc2_hsotg *hsotg, int val)
+{
+ if (DWC2_OUT_OF_BOUNDS(val, 0, 1)) {
+ if (val >= 0) {
+ dev_err(hsotg->dev,
+ "'%d' invalid for parameter change_speed_quirk\n",
+ val);
+ dev_err(hsotg->dev, "change_speed_quirk must be 0 or 1\n");
+ }
+ val = 0;
+ dev_dbg(hsotg->dev, "Setting change_speed_quirk to %d\n", val);
+ }
+
+ hsotg->params.change_speed_quirk = val;
+}
+
/**
* dwc2_set_parameters() - Set all core parameters.
*
@@ -1170,6 +1188,7 @@ static void dwc2_set_parameters(struct dwc2_hsotg *hsotg,
dwc2_set_param_uframe_sched(hsotg, params->uframe_sched);
dwc2_set_param_external_id_pin_ctl(hsotg, params->external_id_pin_ctl);
dwc2_set_param_hibernation(hsotg, params->hibernation);
+ dwc2_set_change_speed_quirk(hsotg, params->change_speed_quirk);

/*
* Set devicetree-only parameters. These parameters do not
--
2.7.4