u-boot/drivers/clk/tegra/tegra-car-clk.c

/*
 * Copyright (c) 2016, NVIDIA CORPORATION.
 *
 * SPDX-License-Identifier: GPL-2.0
 */

#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <asm/arch/clock.h>
#include <asm/arch-tegra/clk_rst.h>

static int tegra_car_clk_request(struct clk *clk)
{
	debug("%s(clk=%p) (dev=%p, id=%lu)\n", __func__, clk, clk->dev,
	      clk->id);

	/*
	 * Note that the first PERIPH_ID_COUNT clock IDs (where the value
	 * varies per SoC) are the peripheral clocks, which use a numbering
	 * scheme that matches HW registers 1:1. There are other clock IDs
	 * beyond this that are assigned arbitrarily by the Tegra CAR DT
	 * binding. Due to the implementation of this driver, it currently
	 * only supports the peripheral IDs.
	 */
	if (clk->id >= PERIPH_ID_COUNT)
		return -EINVAL;

	return 0;
}

static int tegra_car_clk_free(struct clk *clk)
{
	debug("%s(clk=%p) (dev=%p, id=%lu)\n", __func__, clk, clk->dev,
	      clk->id);

	return 0;
}

static ulong tegra_car_clk_get_rate(struct clk *clk)
{
	enum clock_id parent;

	debug("%s(clk=%p) (dev=%p, id=%lu)\n", __func__, clk, clk->dev,
	      clk->id);

	parent = clock_get_periph_parent(clk->id);
	return clock_get_periph_rate(clk->id, parent);
}

static ulong tegra_car_clk_set_rate(struct clk *clk, ulong rate)
{
	enum clock_id parent;

	debug("%s(clk=%p, rate=%lu) (dev=%p, id=%lu)\n", __func__, clk, rate,
	      clk->dev, clk->id);

	parent = clock_get_periph_parent(clk->id);
	return clock_adjust_periph_pll_div(clk->id, parent, rate, NULL);
}

static int tegra_car_clk_enable(struct clk *clk)
{
	debug("%s(clk=%p) (dev=%p, id=%lu)\n", __func__, clk, clk->dev,
	      clk->id);

	clock_enable(clk->id);

	return 0;
}

static int tegra_car_clk_disable(struct clk *clk)
{
	debug("%s(clk=%p) (dev=%p, id=%lu)\n", __func__, clk, clk->dev,
	      clk->id);

	clock_disable(clk->id);

	return 0;
}

static struct clk_ops tegra_car_clk_ops = {
	.request = tegra_car_clk_request,
	.free = tegra_car_clk_free,
	.get_rate = tegra_car_clk_get_rate,
	.set_rate = tegra_car_clk_set_rate,
	.enable = tegra_car_clk_enable,
	.disable = tegra_car_clk_disable,
};

static int tegra_car_clk_probe(struct udevice *dev)
{
	debug("%s(dev=%p)\n", __func__, dev);

	return 0;
}

U_BOOT_DRIVER(tegra_car_clk) = {
	.name = "tegra_car_clk",
	.id = UCLASS_CLK,
	.probe = tegra_car_clk_probe,
	.ops = &tegra_car_clk_ops,
};