u-boot/drivers/clk/clk_scmi.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2019-2020 Linaro Limited
 */
#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <scmi_agent.h>
#include <scmi_protocols.h>
#include <asm/types.h>

static int scmi_clk_gate(struct clk *clk, int enable)
{
	struct scmi_clk_state_in in = {
		.clock_id = clk->id,
		.attributes = enable,
	};
	struct scmi_clk_state_out out;
	struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
					  SCMI_CLOCK_CONFIG_SET,
					  in, out);
	int ret;

	ret = devm_scmi_process_msg(clk->dev->parent, &msg);
	if (ret)
		return ret;

	return scmi_to_linux_errno(out.status);
}

static int scmi_clk_enable(struct clk *clk)
{
	return scmi_clk_gate(clk, 1);
}

static int scmi_clk_disable(struct clk *clk)
{
	return scmi_clk_gate(clk, 0);
}

static ulong scmi_clk_get_rate(struct clk *clk)
{
	struct scmi_clk_rate_get_in in = {
		.clock_id = clk->id,
	};
	struct scmi_clk_rate_get_out out;
	struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
					  SCMI_CLOCK_RATE_GET,
					  in, out);
	int ret;

	ret = devm_scmi_process_msg(clk->dev->parent, &msg);
	if (ret < 0)
		return ret;

	ret = scmi_to_linux_errno(out.status);
	if (ret < 0)
		return ret;

	return (ulong)(((u64)out.rate_msb << 32) | out.rate_lsb);
}

static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
{
	struct scmi_clk_rate_set_in in = {
		.clock_id = clk->id,
		.flags = SCMI_CLK_RATE_ROUND_CLOSEST,
		.rate_lsb = (u32)rate,
		.rate_msb = (u32)((u64)rate >> 32),
	};
	struct scmi_clk_rate_set_out out;
	struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
					  SCMI_CLOCK_RATE_SET,
					  in, out);
	int ret;

	ret = devm_scmi_process_msg(clk->dev->parent, &msg);
	if (ret < 0)
		return ret;

	ret = scmi_to_linux_errno(out.status);
	if (ret < 0)
		return ret;

	return scmi_clk_get_rate(clk);
}

static const struct clk_ops scmi_clk_ops = {
	.enable = scmi_clk_enable,
	.disable = scmi_clk_disable,
	.get_rate = scmi_clk_get_rate,
	.set_rate = scmi_clk_set_rate,
};

U_BOOT_DRIVER(scmi_clock) = {
	.name = "scmi_clk",
	.id = UCLASS_CLK,
	.ops = &scmi_clk_ops,
};