[PATCH v3 10/12] usb: dwc3: gadget: Implement setting of sublink speed

[Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>]

Implement gadget ops udc_set_num_lanes_and_speed. This allows the
gadget/core driver to select number of lanes to use and the sublink
speed the controller supports.

Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
---
 Changes in v3:
 - None
 Changes in v2:
 - None

 drivers/usb/dwc3/core.h   |  2 ++
 drivers/usb/dwc3/gadget.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 0ec675327014..9466c4c36963 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -385,6 +385,8 @@
 #define DWC3_GUCTL2_RST_ACTBITLATER		BIT(14)
 
 /* Device Configuration Register */
+#define DWC3_DCFG_NUMLANES(n)	(((n) & 0x3) << 30) /* DWC_usb32 only */
+
 #define DWC3_DCFG_DEVADDR(addr)	((addr) << 3)
 #define DWC3_DCFG_DEVADDR_MASK	DWC3_DCFG_DEVADDR(0x7f)
 
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 3038dae970f3..b7da4e1c81aa 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2333,6 +2333,62 @@ static void dwc3_gadget_set_speed(struct usb_gadget *g,
 	spin_unlock_irqrestore(&dwc->lock, flags);
 }
 
+static void dwc3_gadget_set_num_lanes_and_speed(struct usb_gadget *g,
+						unsigned int num_lanes,
+						unsigned int ssid)
+{
+	struct dwc3			*dwc = gadget_to_dwc(g);
+	struct usb_sublink_speed	*ssa = NULL;
+	unsigned int			lanes;
+	unsigned long			flags;
+	u32				reg;
+	int				i;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	if (dwc->maximum_speed < USB_SPEED_SUPER_PLUS)
+		goto done;
+
+	for (i = 0; i < g->ssac + 1; i++) {
+		if (g->sublink_speed[i].id == ssid) {
+			ssa = &g->sublink_speed[i];
+			break;
+		}
+	}
+
+	if (!ssa) {
+		dev_err(dwc->dev, "SSID not found (%d)\n", ssid);
+		goto done;
+	}
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+	reg &= ~DWC3_DCFG_SPEED_MASK;
+
+	switch (ssa->mantissa) {
+	case 5:
+		reg |= DWC3_DCFG_SUPERSPEED;
+		break;
+	case 10:
+		reg |= DWC3_DCFG_SUPERSPEED_PLUS;
+		break;
+	default:
+		dev_err(dwc->dev, "invalid lane speed mantissa (%d)\n",
+			ssa->mantissa);
+		goto done;
+	}
+
+	/* Lane configuration is only available to DWC_usb32 */
+	if (DWC3_IP_IS(DWC32)) {
+		lanes = clamp_t(unsigned int, num_lanes, 1,
+				dwc->maximum_num_lanes);
+		reg &= ~DWC3_DCFG_NUMLANES(~0);
+		reg |= DWC3_DCFG_NUMLANES(lanes - 1);
+	}
+
+	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+done:
+	spin_unlock_irqrestore(&dwc->lock, flags);
+}
+
 static const struct usb_gadget_ops dwc3_gadget_ops = {
 	.get_frame		= dwc3_gadget_get_frame,
 	.wakeup			= dwc3_gadget_wakeup,
@@ -2341,6 +2397,7 @@ static const struct usb_gadget_ops dwc3_gadget_ops = {
 	.udc_start		= dwc3_gadget_start,
 	.udc_stop		= dwc3_gadget_stop,
 	.udc_set_speed		= dwc3_gadget_set_speed,
+	.udc_set_num_lanes_and_speed = dwc3_gadget_set_num_lanes_and_speed,
 	.get_config_params	= dwc3_gadget_config_params,
 };
 
@@ -3751,7 +3808,12 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 		goto err4;
 	}
 
-	dwc3_gadget_set_speed(&dwc->gadget, dwc->maximum_speed);
+	if (DWC3_IP_IS(DWC32) && dwc->maximum_speed == USB_SPEED_SUPER_PLUS)
+		dwc3_gadget_set_num_lanes_and_speed(&dwc->gadget,
+						    dwc->maximum_num_lanes,
+						    dwc->gadget.max_speed_ssid);
+	else
+		dwc3_gadget_set_speed(&dwc->gadget, dwc->maximum_speed);
 
 	return 0;
 
-- 
2.11.0