// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Maxime Ripard
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 */

#include <linux/clk-provider.h>
#include <linux/io.h>

#include "ccu_gate.h"
#include "ccu_mult.h"

struct _ccu_mult {
        unsigned long   mult, min, max;
};

static void ccu_mult_find_best(unsigned long parent, unsigned long rate,
                               struct _ccu_mult *mult)
{
        int _mult;

        _mult = rate / parent;
        if (_mult < mult->min)
                _mult = mult->min;

        if (_mult > mult->max)
                _mult = mult->max;

        mult->mult = _mult;
}

static int ccu_mult_determine_rate_helper(struct ccu_mux_internal *mux,
                                          struct clk_rate_request *req,
                                          void *data)
{
        struct ccu_mult *cm = data;
        struct _ccu_mult _cm;

        _cm.min = cm->mult.min;

        if (cm->mult.max)
                _cm.max = cm->mult.max;
        else
                _cm.max = (1 << cm->mult.width) + cm->mult.offset - 1;

        ccu_mult_find_best(req->best_parent_rate, req->rate, &_cm);

        req->rate = req->best_parent_rate * _cm.mult;

        return 0;
}

static void ccu_mult_disable(struct clk_hw *hw)
{
        struct ccu_mult *cm = hw_to_ccu_mult(hw);

        return ccu_gate_helper_disable(&cm->common, cm->enable);
}

static int ccu_mult_enable(struct clk_hw *hw)
{
        struct ccu_mult *cm = hw_to_ccu_mult(hw);

        return ccu_gate_helper_enable(&cm->common, cm->enable);
}

static int ccu_mult_is_enabled(struct clk_hw *hw)
{
        struct ccu_mult *cm = hw_to_ccu_mult(hw);

        return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
}

static unsigned long ccu_mult_recalc_rate(struct clk_hw *hw,
                                        unsigned long parent_rate)
{
        struct ccu_mult *cm = hw_to_ccu_mult(hw);
        unsigned long val;
        u32 reg;

        if (ccu_frac_helper_is_enabled(&cm->common, &cm->frac))
                return ccu_frac_helper_read_rate(&cm->common, &cm->frac);

        reg = readl(cm->common.base + cm->common.reg);
        val = reg >> cm->mult.shift;
        val &= (1 << cm->mult.width) - 1;

        parent_rate = ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
                                                  parent_rate);

        return parent_rate * (val + cm->mult.offset);
}

static int ccu_mult_determine_rate(struct clk_hw *hw,
                                struct clk_rate_request *req)
{
        struct ccu_mult *cm = hw_to_ccu_mult(hw);

        return ccu_mux_helper_determine_rate(&cm->common, &cm->mux,
                                             req, ccu_mult_determine_rate_helper, cm);
}

static int ccu_mult_set_rate(struct clk_hw *hw, unsigned long rate,
                           unsigned long parent_rate)
{
        struct ccu_mult *cm = hw_to_ccu_mult(hw);
        struct _ccu_mult _cm;
        unsigned long flags;
        u32 reg;

        if (ccu_frac_helper_has_rate(&cm->common, &cm->frac, rate)) {
                ccu_frac_helper_enable(&cm->common, &cm->frac);

                return ccu_frac_helper_set_rate(&cm->common, &cm->frac,
                                                rate, cm->lock);
        } else {
                ccu_frac_helper_disable(&cm->common, &cm->frac);
        }

        parent_rate = ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
                                                  parent_rate);

        _cm.min = cm->mult.min;

        if (cm->mult.max)
                _cm.max = cm->mult.max;
        else
                _cm.max = (1 << cm->mult.width) + cm->mult.offset - 1;

        ccu_mult_find_best(parent_rate, rate, &_cm);

        spin_lock_irqsave(cm->common.lock, flags);

        reg = readl(cm->common.base + cm->common.reg);
        reg &= ~GENMASK(cm->mult.width + cm->mult.shift - 1, cm->mult.shift);
        reg |= ((_cm.mult - cm->mult.offset) << cm->mult.shift);

        writel(reg, cm->common.base + cm->common.reg);

        spin_unlock_irqrestore(cm->common.lock, flags);

        ccu_helper_wait_for_lock(&cm->common, cm->lock);

        return 0;
}

static u8 ccu_mult_get_parent(struct clk_hw *hw)
{
        struct ccu_mult *cm = hw_to_ccu_mult(hw);

        return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
}

static int ccu_mult_set_parent(struct clk_hw *hw, u8 index)
{
        struct ccu_mult *cm = hw_to_ccu_mult(hw);

        return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
}

const struct clk_ops ccu_mult_ops = {
        .disable        = ccu_mult_disable,
        .enable         = ccu_mult_enable,
        .is_enabled     = ccu_mult_is_enabled,

        .get_parent     = ccu_mult_get_parent,
        .set_parent     = ccu_mult_set_parent,

        .determine_rate = ccu_mult_determine_rate,
        .recalc_rate    = ccu_mult_recalc_rate,
        .set_rate       = ccu_mult_set_rate,
};
EXPORT_SYMBOL_NS_GPL(ccu_mult_ops, "SUNXI_CCU");