usb: dwc3: add optional PHY interface clocks

On Rockchip RK3588 one of the DWC3 cores is integrated weirdly and
requires two extra clocks to be enabled. Without these extra clocks
hot-plugging USB devices is broken.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20231020150022.48725-3-sebastian.reichel@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/core.c

@@ -854,8 +854,20 @@ static int dwc3_clk_enable(struct dwc3 *dwc)
 	if (ret)
 		goto disable_ref_clk;
 
+	ret = clk_prepare_enable(dwc->utmi_clk);
+	if (ret)
+		goto disable_susp_clk;
+
+	ret = clk_prepare_enable(dwc->pipe_clk);
+	if (ret)
+		goto disable_utmi_clk;
+
 	return 0;
 
+disable_utmi_clk:
+	clk_disable_unprepare(dwc->utmi_clk);
+disable_susp_clk:
+	clk_disable_unprepare(dwc->susp_clk);
 disable_ref_clk:
 	clk_disable_unprepare(dwc->ref_clk);
 disable_bus_clk:
@@ -865,6 +877,8 @@ static int dwc3_clk_enable(struct dwc3 *dwc)
 
 static void dwc3_clk_disable(struct dwc3 *dwc)
 {
+	clk_disable_unprepare(dwc->pipe_clk);
+	clk_disable_unprepare(dwc->utmi_clk);
 	clk_disable_unprepare(dwc->susp_clk);
 	clk_disable_unprepare(dwc->ref_clk);
 	clk_disable_unprepare(dwc->bus_clk);
@@ -1873,6 +1887,20 @@ static int dwc3_get_clocks(struct dwc3 *dwc)
 		}
 	}
 
+	/* specific to Rockchip RK3588 */
+	dwc->utmi_clk = devm_clk_get_optional(dev, "utmi");
+	if (IS_ERR(dwc->utmi_clk)) {
+		return dev_err_probe(dev, PTR_ERR(dwc->utmi_clk),
+				"could not get utmi clock\n");
+	}
+
+	/* specific to Rockchip RK3588 */
+	dwc->pipe_clk = devm_clk_get_optional(dev, "pipe");
+	if (IS_ERR(dwc->pipe_clk)) {
+		return dev_err_probe(dev, PTR_ERR(dwc->pipe_clk),
+				"could not get pipe clock\n");
+	}
+
 	return 0;
 }
 

drivers/usb/dwc3/core.h

@@ -996,6 +996,8 @@ struct dwc3_scratchpad_array {
  * @bus_clk: clock for accessing the registers
  * @ref_clk: reference clock
  * @susp_clk: clock used when the SS phy is in low power (S3) state
+ * @utmi_clk: clock used for USB2 PHY communication
+ * @pipe_clk: clock used for USB3 PHY communication
  * @reset: reset control
  * @regs: base address for our registers
  * @regs_size: address space size
@@ -1167,6 +1169,8 @@ struct dwc3 {
 	struct clk		*bus_clk;
 	struct clk		*ref_clk;
 	struct clk		*susp_clk;
+	struct clk		*utmi_clk;
+	struct clk		*pipe_clk;
 
 	struct reset_control	*reset;