From a8dc4965f09d28a59c156437673ddb66860c847e Mon Sep 17 00:00:00 2001
From: Svyatoslav Ryhel <clamor95@gmail.com>
Date: Wed, 10 Jan 2024 18:09:56 +0200
Subject: [PATCH] clk: clk-gpio: add actual gated clock

Existing gpio-gate-clock driver acts like a simple GPIO switch without any
effect on gated clock. Add actual clock actions into enable/disable ops and
implement get_rate op by passing gated clock if it is enabled.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>
Link: https://lore.kernel.org/r/20240110160956.4476-2-clamor95@gmail.com
[ sorted includes ]
Signed-off-by: Sean Anderson <seanga2@gmail.com>
---
 drivers/clk/clk-gpio.c | 38 +++++++++++++++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c
index 26d795b978..4ed1430657 100644
--- a/drivers/clk/clk-gpio.c
+++ b/drivers/clk/clk-gpio.c
@@ -3,19 +3,23 @@
  * Copyright (C) 2023 Marek Vasut <marek.vasut+renesas@mailbox.org>
  */
 
-#include <asm/gpio.h>
-#include <common.h>
+#include <clk.h>
 #include <clk-uclass.h>
 #include <dm.h>
+#include <linux/clk-provider.h>
+
+#include <asm/gpio.h>
 
 struct clk_gpio_priv {
-	struct gpio_desc	enable;
+	struct gpio_desc	enable;	/* GPIO, controlling the gate */
+	struct clk		*clk;	/* Gated clock */
 };
 
 static int clk_gpio_enable(struct clk *clk)
 {
 	struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
 
+	clk_enable(priv->clk);
 	dm_gpio_set_value(&priv->enable, 1);
 
 	return 0;
@@ -26,21 +30,45 @@ static int clk_gpio_disable(struct clk *clk)
 	struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
 
 	dm_gpio_set_value(&priv->enable, 0);
+	clk_disable(priv->clk);
 
 	return 0;
 }
 
+static ulong clk_gpio_get_rate(struct clk *clk)
+{
+	struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
+
+	return clk_get_rate(priv->clk);
+}
+
 const struct clk_ops clk_gpio_ops = {
 	.enable		= clk_gpio_enable,
 	.disable	= clk_gpio_disable,
+	.get_rate	= clk_gpio_get_rate,
 };
 
 static int clk_gpio_probe(struct udevice *dev)
 {
 	struct clk_gpio_priv *priv = dev_get_priv(dev);
+	int ret;
 
-	return gpio_request_by_name(dev, "enable-gpios", 0,
-				    &priv->enable, GPIOD_IS_OUT);
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		log_debug("%s: Could not get gated clock: %ld\n",
+			  __func__, PTR_ERR(priv->clk));
+		return PTR_ERR(priv->clk);
+	}
+
+	ret = gpio_request_by_name(dev, "enable-gpios", 0,
+				   &priv->enable, GPIOD_IS_OUT);
+	if (ret) {
+		log_debug("%s: Could not decode enable-gpios (%d)\n",
+			  __func__, ret);
+		return ret;
+	}
+
+	return 0;
 }
 
 /*