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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2023 Marek Vasut <marek.vasut+renesas@mailbox.org>
*/
#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; /* 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;
}
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;
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;
}
/*
* When implementing clk-mux-clock, use gpio_request_list_by_name
* and implement get_rate/set_rate/set_parent ops. This should be
* in a separate driver and with separate Kconfig option to enable
* that driver, since unlike Linux implementation, the U-Boot DM
* integration would be orthogonal to this driver.
*/
static const struct udevice_id clk_gpio_match[] = {
{ .compatible = "gpio-gate-clock" },
{ /* sentinel */ }
};
U_BOOT_DRIVER(gpio_gate_clock) = {
.name = "gpio_clock",
.id = UCLASS_CLK,
.of_match = clk_gpio_match,
.probe = clk_gpio_probe,
.priv_auto = sizeof(struct clk_gpio_priv),
.ops = &clk_gpio_ops,
.flags = DM_FLAG_PRE_RELOC,
};
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