u-boot/drivers/clk/clk_fixed_rate.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Masahiro Yamada <yamada.masahiro@socionext.com>
 */

#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <dm/device-internal.h>
#include <linux/clk-provider.h>

#define UBOOT_DM_CLK_FIXED_RATE "fixed_rate_clock"
#define UBOOT_DM_CLK_FIXED_RATE_RAW "fixed_rate_raw_clock"

static ulong clk_fixed_rate_get_rate(struct clk *clk)
{
	return to_clk_fixed_rate(clk->dev)->fixed_rate;
}

/* avoid clk_enable() return -ENOSYS */
static int dummy_enable(struct clk *clk)
{
	return 0;
}

const struct clk_ops clk_fixed_rate_ops = {
	.get_rate = clk_fixed_rate_get_rate,
	.enable = dummy_enable,
	.disable = dummy_enable,
};

void clk_fixed_rate_ofdata_to_plat_(struct udevice *dev,
				    struct clk_fixed_rate *plat)
{
	struct clk *clk = &plat->clk;
	if (CONFIG_IS_ENABLED(OF_REAL))
		plat->fixed_rate = dev_read_u32_default(dev, "clock-frequency",
							0);

	/* Make fixed rate clock accessible from higher level struct clk */
	/* FIXME: This is not allowed */
	dev_set_uclass_priv(dev, clk);

	clk->dev = dev;
	clk->enable_count = 0;
}

static ulong clk_fixed_rate_raw_get_rate(struct clk *clk)
{
	return container_of(clk, struct clk_fixed_rate, clk)->fixed_rate;
}

const struct clk_ops clk_fixed_rate_raw_ops = {
	.get_rate = clk_fixed_rate_raw_get_rate,
};

static int clk_fixed_rate_of_to_plat(struct udevice *dev)
{
	clk_fixed_rate_ofdata_to_plat_(dev, to_clk_fixed_rate(dev));

	return 0;
}

#if CONFIG_IS_ENABLED(CLK_CCF)
struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
				    ulong rate)
{
	struct clk *clk;
	struct clk_fixed_rate *fixed;
	int ret;

	fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
	if (!fixed)
		return ERR_PTR(-ENOMEM);

	fixed->fixed_rate = rate;

	clk = &fixed->clk;

	ret = clk_register(clk, UBOOT_DM_CLK_FIXED_RATE_RAW, name, NULL);
	if (ret) {
		kfree(fixed);
		return ERR_PTR(ret);
	}

	return clk;
}
#endif

static const struct udevice_id clk_fixed_rate_match[] = {
	{
		.compatible = "fixed-clock",
	},
	{ /* sentinel */ }
};

U_BOOT_DRIVER(fixed_clock) = {
	.name = "fixed_clock",
	.id = UCLASS_CLK,
	.of_match = clk_fixed_rate_match,
	.of_to_plat = clk_fixed_rate_of_to_plat,
	.plat_auto	= sizeof(struct clk_fixed_rate),
	.ops = &clk_fixed_rate_ops,
	.flags = DM_FLAG_PRE_RELOC,
};

U_BOOT_DRIVER(clk_fixed_rate_raw) = {
	.name = UBOOT_DM_CLK_FIXED_RATE_RAW,
	.id = UCLASS_CLK,
	.ops = &clk_fixed_rate_raw_ops,
	.flags = DM_FLAG_PRE_RELOC,
};