usb: dwc3: Get clocks individually

Instead of grabbing all clocks in bulk, grab them individually. This will
allow us to get the frequency or otherwise deal with discrete clocks. This
may break some platforms if they use a clock which doesn't use one of the
documented names.

Reviewed-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/20220127200636.1456175-3-sean.anderson@seco.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/core.c

@@ -745,6 +745,38 @@ static int dwc3_phy_setup(struct dwc3 *dwc)
 	return 0;
 }
 
+static int dwc3_clk_enable(struct dwc3 *dwc)
+{
+	int ret;
+
+	ret = clk_prepare_enable(dwc->bus_clk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(dwc->ref_clk);
+	if (ret)
+		goto disable_bus_clk;
+
+	ret = clk_prepare_enable(dwc->susp_clk);
+	if (ret)
+		goto disable_ref_clk;
+
+	return 0;
+
+disable_ref_clk:
+	clk_disable_unprepare(dwc->ref_clk);
+disable_bus_clk:
+	clk_disable_unprepare(dwc->bus_clk);
+	return ret;
+}
+
+static void dwc3_clk_disable(struct dwc3 *dwc)
+{
+	clk_disable_unprepare(dwc->susp_clk);
+	clk_disable_unprepare(dwc->ref_clk);
+	clk_disable_unprepare(dwc->bus_clk);
+}
+
 static void dwc3_core_exit(struct dwc3 *dwc)
 {
 	dwc3_event_buffers_cleanup(dwc);
@@ -758,7 +790,7 @@ static void dwc3_core_exit(struct dwc3 *dwc)
 	usb_phy_set_suspend(dwc->usb3_phy, 1);
 	phy_power_off(dwc->usb2_generic_phy);
 	phy_power_off(dwc->usb3_generic_phy);
-	clk_bulk_disable_unprepare(dwc->num_clks, dwc->clks);
+	dwc3_clk_disable(dwc);
 	reset_control_assert(dwc->reset);
 }
 
@@ -1605,25 +1637,31 @@ static int dwc3_probe(struct platform_device *pdev)
 		return PTR_ERR(dwc->reset);
 
 	if (dev->of_node) {
-		ret = devm_clk_bulk_get_all(dev, &dwc->clks);
-		if (ret == -EPROBE_DEFER)
-			return ret;
 		/*
 		 * Clocks are optional, but new DT platforms should support all
 		 * clocks as required by the DT-binding.
 		 */
-		if (ret < 0)
-			dwc->num_clks = 0;
-		else
-			dwc->num_clks = ret;
-
+		dwc->bus_clk = devm_clk_get_optional(dev, "bus_early");
+		if (IS_ERR(dwc->bus_clk))
+			return dev_err_probe(dev, PTR_ERR(dwc->bus_clk),
+					     "could not get bus clock\n");
+
+		dwc->ref_clk = devm_clk_get_optional(dev, "ref");
+		if (IS_ERR(dwc->ref_clk))
+			return dev_err_probe(dev, PTR_ERR(dwc->ref_clk),
+					     "could not get ref clock\n");
+
+		dwc->susp_clk = devm_clk_get_optional(dev, "suspend");
+		if (IS_ERR(dwc->susp_clk))
+			return dev_err_probe(dev, PTR_ERR(dwc->susp_clk),
+					     "could not get suspend clock\n");
 	}
 
 	ret = reset_control_deassert(dwc->reset);
 	if (ret)
 		return ret;
 
-	ret = clk_bulk_prepare_enable(dwc->num_clks, dwc->clks);
+	ret = dwc3_clk_enable(dwc);
 	if (ret)
 		goto assert_reset;
 
@@ -1711,7 +1749,7 @@ static int dwc3_probe(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 
 disable_clks:
-	clk_bulk_disable_unprepare(dwc->num_clks, dwc->clks);
+	dwc3_clk_disable(dwc);
 assert_reset:
 	reset_control_assert(dwc->reset);
 
@@ -1755,7 +1793,7 @@ static int dwc3_core_init_for_resume(struct dwc3 *dwc)
 	if (ret)
 		return ret;
 
-	ret = clk_bulk_prepare_enable(dwc->num_clks, dwc->clks);
+	ret = dwc3_clk_enable(dwc);
 	if (ret)
 		goto assert_reset;
 
@@ -1766,7 +1804,7 @@ static int dwc3_core_init_for_resume(struct dwc3 *dwc)
 	return 0;
 
 disable_clks:
-	clk_bulk_disable_unprepare(dwc->num_clks, dwc->clks);
+	dwc3_clk_disable(dwc);
 assert_reset:
 	reset_control_assert(dwc->reset);
 

drivers/usb/dwc3/core.h

@@ -978,8 +978,9 @@ struct dwc3_scratchpad_array {
  * @eps: endpoint array
  * @gadget: device side representation of the peripheral controller
  * @gadget_driver: pointer to the gadget driver
- * @clks: array of clocks
- * @num_clks: number of clocks
+ * @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
  * @reset: reset control
  * @regs: base address for our registers
  * @regs_size: address space size
@@ -1134,8 +1135,9 @@ struct dwc3 {
 	struct usb_gadget	*gadget;
 	struct usb_gadget_driver *gadget_driver;
 
-	struct clk_bulk_data	*clks;
-	int			num_clks;
+	struct clk		*bus_clk;
+	struct clk		*ref_clk;
+	struct clk		*susp_clk;
 
 	struct reset_control	*reset;