From 59b1f262d8ae5a1b8107eaaacfda0255eb243e14 Mon Sep 17 00:00:00 2001
From: Frank Wang <frank.wang@rock-chips.com>
Date: Thu, 5 Jan 2017 15:08:57 +0800
Subject: [PATCH] usb: dwc2: add multiple clock handling

Originally, dwc2 just handle one clock named otg, however, it may have
two or more clock need to manage for some new SoCs, so this adds
change clk to clk's array of dwc2_hsotg to handle more clocks operation.

Change-Id: I661297ef908d9eace2215205018fa94d12cea128
Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
---
 drivers/usb/dwc2/core.h     |  5 ++++-
 drivers/usb/dwc2/platform.c | 38 ++++++++++++++++++++++++-------------
 2 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 3ff41d87125a..86020473b1be 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -68,6 +68,9 @@
 /* Maximum number of Endpoints/HostChannels */
 #define MAX_EPS_CHANNELS	16
 
+/* Maximum number of dwc2 clocks */
+#define DWC2_MAX_CLKS 3
+
 /* dwc2-hsotg declarations */
 static const char * const dwc2_hsotg_supply_names[] = {
 	"vusb_d",               /* digital USB supply, 1.2V */
@@ -1031,7 +1034,7 @@ struct dwc2_hsotg {
 	spinlock_t lock;
 	void *priv;
 	int     irq;
-	struct clk *clk;
+	struct clk *clks[DWC2_MAX_CLKS];
 	struct reset_control *reset;
 	struct reset_control *reset_ecc;
 
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 748763bdcc98..97838c7aec03 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -124,17 +124,20 @@ static int dwc2_get_dr_mode(struct dwc2_hsotg *hsotg)
 static int __dwc2_lowlevel_hw_enable(struct dwc2_hsotg *hsotg)
 {
 	struct platform_device *pdev = to_platform_device(hsotg->dev);
-	int ret;
+	int clk, ret;
 
 	ret = regulator_bulk_enable(ARRAY_SIZE(hsotg->supplies),
 				    hsotg->supplies);
 	if (ret)
 		return ret;
 
-	if (hsotg->clk) {
-		ret = clk_prepare_enable(hsotg->clk);
-		if (ret)
+	for (clk = 0; clk < DWC2_MAX_CLKS && hsotg->clks[clk]; clk++) {
+		ret = clk_prepare_enable(hsotg->clks[clk]);
+		if (ret) {
+			while (--clk >= 0)
+				clk_disable_unprepare(hsotg->clks[clk]);
 			return ret;
+		}
 	}
 
 	if (hsotg->uphy) {
@@ -169,7 +172,7 @@ int dwc2_lowlevel_hw_enable(struct dwc2_hsotg *hsotg)
 static int __dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
 {
 	struct platform_device *pdev = to_platform_device(hsotg->dev);
-	int ret = 0;
+	int clk, ret = 0;
 
 	if (hsotg->uphy) {
 		usb_phy_shutdown(hsotg->uphy);
@@ -183,8 +186,9 @@ static int __dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
 	if (ret)
 		return ret;
 
-	if (hsotg->clk)
-		clk_disable_unprepare(hsotg->clk);
+	for (clk = DWC2_MAX_CLKS - 1; clk >= 0; clk--)
+		if (hsotg->clks[clk])
+			clk_disable_unprepare(hsotg->clks[clk]);
 
 	ret = regulator_bulk_disable(ARRAY_SIZE(hsotg->supplies),
 				     hsotg->supplies);
@@ -218,7 +222,7 @@ static void dwc2_reset_phy_work(struct work_struct *data)
 
 static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
 {
-	int i, ret;
+	int i, clk, ret;
 
 	hsotg->reset = devm_reset_control_get_optional(hsotg->dev, "dwc2");
 	if (IS_ERR(hsotg->reset)) {
@@ -292,11 +296,19 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
 			hsotg->phyif = GUSBCFG_PHYIF8;
 	}
 
-	/* Clock */
-	hsotg->clk = devm_clk_get(hsotg->dev, "otg");
-	if (IS_ERR(hsotg->clk)) {
-		hsotg->clk = NULL;
-		dev_dbg(hsotg->dev, "cannot get otg clock\n");
+	for (clk = 0; clk < DWC2_MAX_CLKS; clk++) {
+		hsotg->clks[clk] = of_clk_get(hsotg->dev->of_node, clk);
+		if (IS_ERR(hsotg->clks[clk])) {
+			ret = PTR_ERR(hsotg->clks[clk]);
+			if (ret == -EPROBE_DEFER) {
+				while (--clk >= 0)
+					clk_put(hsotg->clks[clk]);
+				return ret;
+			}
+
+			hsotg->clks[clk] = NULL;
+			break;
+		}
 	}
 
 	/* Regulators */