clk: renesas: rcar-usb2-clock-sel: Add reset_control

This hardware needs to deassert resets of both host and peripheral.
So, this patch adds reset control.

Signed-off-by: Yoshihiro Shimoda <[email protected]>
Link: https://lore.kernel.org/r/1583304137-28482-5-git-send-email-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Geert Uytterhoeven <[email protected]>

Author: shimoday

drivers/clk/renesas/Kconfig

@@ -161,6 +161,7 @@ config CLK_RCAR_GEN3_CPG
 config CLK_RCAR_USB2_CLOCK_SEL
 	bool "Renesas R-Car USB2 clock selector support"
 	depends on ARCH_RENESAS || COMPILE_TEST
+	select RESET_CONTROLLER
 	help
 	  This is a driver for R-Car USB2 clock selector
 

drivers/clk/renesas/rcar-usb2-clock-sel.c

@@ -19,6 +19,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 
 #define USB20_CLKSET0		0x00
@@ -35,6 +36,7 @@ struct usb2_clock_sel_priv {
 	void __iomem *base;
 	struct clk_hw hw;
 	struct clk_bulk_data clks[ARRAY_SIZE(rcar_usb2_clocks)];
+	struct reset_control *rsts;
 	bool extal;
 	bool xtal;
 };
@@ -62,10 +64,16 @@ static int usb2_clock_sel_enable(struct clk_hw *hw)
 	struct usb2_clock_sel_priv *priv = to_priv(hw);
 	int ret;
 
-	ret = clk_bulk_prepare_enable(ARRAY_SIZE(priv->clks), priv->clks);
+	ret = reset_control_deassert(priv->rsts);
 	if (ret)
 		return ret;
 
+	ret = clk_bulk_prepare_enable(ARRAY_SIZE(priv->clks), priv->clks);
+	if (ret) {
+		reset_control_assert(priv->rsts);
+		return ret;
+	}
+
 	usb2_clock_sel_enable_extal_only(priv);
 
 	return 0;
@@ -78,6 +86,7 @@ static void usb2_clock_sel_disable(struct clk_hw *hw)
 	usb2_clock_sel_disable_extal_only(priv);
 
 	clk_bulk_disable_unprepare(ARRAY_SIZE(priv->clks), priv->clks);
+	reset_control_assert(priv->rsts);
 }
 
 /*
@@ -151,6 +160,10 @@ static int rcar_usb2_clock_sel_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
+	priv->rsts = devm_reset_control_array_get(dev, true, false);
+	if (IS_ERR(priv->rsts))
+		return PTR_ERR(priv->rsts);
+
 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);