linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * System Control and Power Interface (SCMI) Protocol based clock driver

 *

 * Copyright (C) 2018 ARM Ltd.

 */

​

#include <linux/clk-provider.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/of.h>

#include <linux/module.h>

#include <linux/scmi_protocol.h>

#include <asm/div64.h>

​

struct scmi_clk {

    u32 id;

    struct clk_hw hw;

    const struct scmi_clock_info *info;

    const struct scmi_handle *handle;

};

​

#define to_scmi_clk(clk) container_of(clk, struct scmi_clk, hw)

​

static unsigned long scmi_clk_recalc_rate(struct clk_hw *hw,

                      unsigned long parent_rate)

{

    int ret;

    u64 rate;

    struct scmi_clk *clk = to_scmi_clk(hw);

​

    ret = clk->handle->clk_ops->rate_get(clk->handle, clk->id, &rate);

    if (ret)

        return 0;

    return rate;

}

​

static long scmi_clk_round_rate(struct clk_hw *hw, unsigned long rate,

                unsigned long *parent_rate)

{

    u64 fmin, fmax, ftmp;

    struct scmi_clk *clk = to_scmi_clk(hw);

​

    /*

     * We can't figure out what rate it will be, so just return the

     * rate back to the caller. scmi_clk_recalc_rate() will be called

     * after the rate is set and we'll know what rate the clock is

     * running at then.

     */

    if (clk->info->rate_discrete)

        return rate;

​

    fmin = clk->info->range.min_rate;

    fmax = clk->info->range.max_rate;

    if (rate <= fmin)

        return fmin;

    else if (rate >= fmax)

        return fmax;

​

    ftmp = rate - fmin;

    ftmp += clk->info->range.step_size - 1; /* to round up */

    do_div(ftmp, clk->info->range.step_size);

​