usb: mtu3: add optional mcu and dma bus clocks

There are mcu_bus and dma_bus clocks needed to be turned on/off by
driver on some SoCs, so add them as optional ones
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/mtu3/mtu3.h

@@ -206,6 +206,9 @@ struct otg_switch_mtk {
  * @ippc_base: register base address of IP Power and Clock interface (IPPC)
  * @vusb33: usb3.3V shared by device/host IP
  * @sys_clk: system clock of mtu3, shared by device/host IP
+ * @ref_clk: reference clock
+ * @mcu_clk: mcu_bus_ck clock for AHB bus etc
+ * @dma_clk: dma_bus_ck clock for AXI bus etc
  * @dr_mode: works in which mode:
  *		host only, device only or dual-role mode
  * @u2_ports: number of usb2.0 host ports
@@ -226,6 +229,8 @@ struct ssusb_mtk {
 	struct regulator *vusb33;
 	struct clk *sys_clk;
 	struct clk *ref_clk;
+	struct clk *mcu_clk;
+	struct clk *dma_clk;
 	/* otg */
 	struct otg_switch_mtk otg_switch;
 	enum usb_dr_mode dr_mode;

drivers/usb/mtu3/mtu3_plat.c

@@ -110,15 +110,9 @@ static void ssusb_phy_power_off(struct ssusb_mtk *ssusb)
 		phy_power_off(ssusb->phys[i]);
 }
 
-static int ssusb_rscs_init(struct ssusb_mtk *ssusb)
+static int ssusb_clks_enable(struct ssusb_mtk *ssusb)
 {
-	int ret = 0;
-
-	ret = regulator_enable(ssusb->vusb33);
-	if (ret) {
-		dev_err(ssusb->dev, "failed to enable vusb33\n");
-		goto vusb33_err;
-	}
+	int ret;
 
 	ret = clk_prepare_enable(ssusb->sys_clk);
 	if (ret) {
@@ -132,6 +126,52 @@ static int ssusb_rscs_init(struct ssusb_mtk *ssusb)
 		goto ref_clk_err;
 	}
 
+	ret = clk_prepare_enable(ssusb->mcu_clk);
+	if (ret) {
+		dev_err(ssusb->dev, "failed to enable mcu_clk\n");
+		goto mcu_clk_err;
+	}
+
+	ret = clk_prepare_enable(ssusb->dma_clk);
+	if (ret) {
+		dev_err(ssusb->dev, "failed to enable dma_clk\n");
+		goto dma_clk_err;
+	}
+
+	return 0;
+
+dma_clk_err:
+	clk_disable_unprepare(ssusb->mcu_clk);
+mcu_clk_err:
+	clk_disable_unprepare(ssusb->ref_clk);
+ref_clk_err:
+	clk_disable_unprepare(ssusb->sys_clk);
+sys_clk_err:
+	return ret;
+}
+
+static void ssusb_clks_disable(struct ssusb_mtk *ssusb)
+{
+	clk_disable_unprepare(ssusb->dma_clk);
+	clk_disable_unprepare(ssusb->mcu_clk);
+	clk_disable_unprepare(ssusb->ref_clk);
+	clk_disable_unprepare(ssusb->sys_clk);
+}
+
+static int ssusb_rscs_init(struct ssusb_mtk *ssusb)
+{
+	int ret = 0;
+
+	ret = regulator_enable(ssusb->vusb33);
+	if (ret) {
+		dev_err(ssusb->dev, "failed to enable vusb33\n");
+		goto vusb33_err;
+	}
+
+	ret = ssusb_clks_enable(ssusb);
+	if (ret)
+		goto clks_err;
+
 	ret = ssusb_phy_init(ssusb);
 	if (ret) {
 		dev_err(ssusb->dev, "failed to init phy\n");
@@ -149,20 +189,16 @@ static int ssusb_rscs_init(struct ssusb_mtk *ssusb)
 phy_err:
 	ssusb_phy_exit(ssusb);
 phy_init_err:
-	clk_disable_unprepare(ssusb->ref_clk);
-ref_clk_err:
-	clk_disable_unprepare(ssusb->sys_clk);
-sys_clk_err:
+	ssusb_clks_disable(ssusb);
+clks_err:
 	regulator_disable(ssusb->vusb33);
 vusb33_err:
-
 	return ret;
 }
 
 static void ssusb_rscs_exit(struct ssusb_mtk *ssusb)
 {
-	clk_disable_unprepare(ssusb->sys_clk);
-	clk_disable_unprepare(ssusb->ref_clk);
+	ssusb_clks_disable(ssusb);
 	regulator_disable(ssusb->vusb33);
 	ssusb_phy_power_off(ssusb);
 	ssusb_phy_exit(ssusb);
@@ -203,6 +239,19 @@ static int get_iddig_pinctrl(struct ssusb_mtk *ssusb)
 	return 0;
 }
 
+/* ignore the error if the clock does not exist */
+static struct clk *get_optional_clk(struct device *dev, const char *id)
+{
+	struct clk *opt_clk;
+
+	opt_clk = devm_clk_get(dev, id);
+	/* ignore error number except EPROBE_DEFER */
+	if (IS_ERR(opt_clk) && (PTR_ERR(opt_clk) != -EPROBE_DEFER))
+		opt_clk = NULL;
+
+	return opt_clk;
+}
+
 static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
 {
 	struct device_node *node = pdev->dev.of_node;
@@ -225,18 +274,17 @@ static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
 		return PTR_ERR(ssusb->sys_clk);
 	}
 
-	/*
-	 * reference clock is usually a "fixed-clock", make it optional
-	 * for backward compatibility and ignore the error if it does
-	 * not exist.
-	 */
-	ssusb->ref_clk = devm_clk_get(dev, "ref_ck");
-	if (IS_ERR(ssusb->ref_clk)) {
-		if (PTR_ERR(ssusb->ref_clk) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+	ssusb->ref_clk = get_optional_clk(dev, "ref_ck");
+	if (IS_ERR(ssusb->ref_clk))
+		return PTR_ERR(ssusb->ref_clk);
 
-		ssusb->ref_clk = NULL;
-	}
+	ssusb->mcu_clk = get_optional_clk(dev, "mcu_ck");
+	if (IS_ERR(ssusb->mcu_clk))
+		return PTR_ERR(ssusb->mcu_clk);
+
+	ssusb->dma_clk = get_optional_clk(dev, "dma_ck");
+	if (IS_ERR(ssusb->dma_clk))
+		return PTR_ERR(ssusb->dma_clk);
 
 	ssusb->num_phys = of_count_phandle_with_args(node,
 			"phys", "#phy-cells");
@@ -451,8 +499,7 @@ static int __maybe_unused mtu3_suspend(struct device *dev)
 
 	ssusb_host_disable(ssusb, true);
 	ssusb_phy_power_off(ssusb);
-	clk_disable_unprepare(ssusb->sys_clk);
-	clk_disable_unprepare(ssusb->ref_clk);
+	ssusb_clks_disable(ssusb);
 	ssusb_wakeup_enable(ssusb);
 
 	return 0;
@@ -470,27 +517,21 @@ static int __maybe_unused mtu3_resume(struct device *dev)
 		return 0;
 
 	ssusb_wakeup_disable(ssusb);
-	ret = clk_prepare_enable(ssusb->sys_clk);
-	if (ret)
-		goto err_sys_clk;
-
-	ret = clk_prepare_enable(ssusb->ref_clk);
+	ret = ssusb_clks_enable(ssusb);
 	if (ret)
-		goto err_ref_clk;
+		goto clks_err;
 
 	ret = ssusb_phy_power_on(ssusb);
 	if (ret)
-		goto err_power_on;
+		goto phy_err;
 
 	ssusb_host_enable(ssusb);
 
 	return 0;
 
-err_power_on:
-	clk_disable_unprepare(ssusb->ref_clk);
-err_ref_clk:
-	clk_disable_unprepare(ssusb->sys_clk);
-err_sys_clk:
+phy_err:
+	ssusb_clks_disable(ssusb);
+clks_err:
 	return ret;
 }