[PATCH v1 1/1] clk: clk-gpio: add actual gated clock

[Svyatoslav Ryhel]

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 <clamo...@gmail.com>
---
 drivers/clk/clk-gpio.c | 47 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c
index 26d795b978..a55470cfbf 100644
--- a/drivers/clk/clk-gpio.c
+++ b/drivers/clk/clk-gpio.c
@@ -3,19 +3,23 @@
  * Copyright (C) 2023 Marek Vasut <marek.vasut+rene...@mailbox.org>
  */
 
-#include <asm/gpio.h>
-#include <common.h>
-#include <clk-uclass.h>
+#include <clk.h>
 #include <dm.h>
+#include <clk-uclass.h>
+#include <linux/clk-provider.h>
+
+#include <asm/gpio.h>
 
 struct clk_gpio_priv {
        struct gpio_desc        enable;
+       struct clk              *clk;
 };
 
 static int clk_gpio_enable(struct clk *clk)
 {
        struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
 
+       clk_prepare_enable(priv->clk);
        dm_gpio_set_value(&priv->enable, 1);
 
        return 0;
@@ -26,21 +30,50 @@ 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_unprepare(priv->clk);
 
        return 0;
 }
 
+static ulong clk_gpio_get_rate(struct clk *clk)
+{
+       struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
+       int ret;
+
+       ret = dm_gpio_get_value(&priv->enable);
+       if (ret)
+               return clk_get_rate(priv->clk);
+       else
+               return -EINVAL;
+}
+
 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)
+static int clk_gpio_of_to_plat(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_err("%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_err("%s: Could not decode enable-gpios (%d)\n",
+                       __func__, ret);
+               return ret;
+       }
+
+       return 0;
 }
 
 /*
@@ -59,7 +92,7 @@ U_BOOT_DRIVER(gpio_gate_clock) = {
        .name           = "gpio_clock",
        .id             = UCLASS_CLK,
        .of_match       = clk_gpio_match,
-       .probe          = clk_gpio_probe,
+       .of_to_plat     = clk_gpio_of_to_plat,
        .priv_auto      = sizeof(struct clk_gpio_priv),
        .ops            = &clk_gpio_ops,
        .flags          = DM_FLAG_PRE_RELOC,
-- 
2.40.1