root/drivers/clk/mmp/clk-mix.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * mmp mix(div and mux) clock operation source file
 *
 * Copyright (C) 2014 Marvell
 * Chao Xie <chao.xie@marvell.com>
 */

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

#include "clk.h"

/*
 * The mix clock is a clock combined mux and div type clock.
 * Because the div field and mux field need to be set at same
 * time, we can not divide it into 2 types of clock
 */

#define to_clk_mix(hw)  container_of(hw, struct mmp_clk_mix, hw)

static unsigned int _get_maxdiv(struct mmp_clk_mix *mix)
{
        unsigned int div_mask = (1 << mix->reg_info.width_div) - 1;
        unsigned int maxdiv = 0;
        struct clk_div_table *clkt;

        if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
                return div_mask;
        if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
                return 1 << div_mask;
        if (mix->div_table) {
                for (clkt = mix->div_table; clkt->div; clkt++)
                        if (clkt->div > maxdiv)
                                maxdiv = clkt->div;
                return maxdiv;
        }
        return div_mask + 1;
}

static unsigned int _get_div(struct mmp_clk_mix *mix, unsigned int val)
{
        struct clk_div_table *clkt;

        if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
                return val;
        if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
                return 1 << val;
        if (mix->div_table) {
                for (clkt = mix->div_table; clkt->div; clkt++)
                        if (clkt->val == val)
                                return clkt->div;
                if (clkt->div == 0)
                        return 0;
        }
        return val + 1;
}

static unsigned int _get_mux(struct mmp_clk_mix *mix, unsigned int val)
{
        int num_parents = clk_hw_get_num_parents(&mix->hw);
        int i;

        if (mix->mux_flags & CLK_MUX_INDEX_BIT)
                return ffs(val) - 1;
        if (mix->mux_flags & CLK_MUX_INDEX_ONE)
                return val - 1;
        if (mix->mux_table) {
                for (i = 0; i < num_parents; i++)
                        if (mix->mux_table[i] == val)
                                return i;
                if (i == num_parents)
                        return 0;
        }

        return val;
}
static unsigned int _get_div_val(struct mmp_clk_mix *mix, unsigned int div)
{
        struct clk_div_table *clkt;

        if (mix->div_flags & CLK_DIVIDER_ONE_BASED)
                return div;
        if (mix->div_flags & CLK_DIVIDER_POWER_OF_TWO)
                return __ffs(div);
        if (mix->div_table) {
                for (clkt = mix->div_table; clkt->div; clkt++)
                        if (clkt->div == div)
                                return clkt->val;
                if (clkt->div == 0)
                        return 0;
        }

        return div - 1;
}

static unsigned int _get_mux_val(struct mmp_clk_mix *mix, unsigned int mux)
{
        if (mix->mux_table)
                return mix->mux_table[mux];

        return mux;
}

static void _filter_clk_table(struct mmp_clk_mix *mix,
                                struct mmp_clk_mix_clk_table *table,
                                unsigned int table_size)
{
        int i;
        struct mmp_clk_mix_clk_table *item;
        struct clk_hw *parent, *hw;
        unsigned long parent_rate;

        hw = &mix->hw;

        for (i = 0; i < table_size; i++) {
                item = &table[i];
                parent = clk_hw_get_parent_by_index(hw, item->parent_index);
                parent_rate = clk_hw_get_rate(parent);
                if (parent_rate % item->rate) {
                        item->valid = 0;
                } else {
                        item->divisor = parent_rate / item->rate;
                        item->valid = 1;
                }
        }
}

static int _set_rate(struct mmp_clk_mix *mix, u32 mux_val, u32 div_val,
                        unsigned int change_mux, unsigned int change_div)
{
        struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
        u8 width, shift;
        u32 mux_div, fc_req;
        int ret, timeout = 50;
        unsigned long flags = 0;

        if (!change_mux && !change_div)
                return -EINVAL;

        if (mix->lock)
                spin_lock_irqsave(mix->lock, flags);

        if (mix->type == MMP_CLK_MIX_TYPE_V1
                || mix->type == MMP_CLK_MIX_TYPE_V2)
                mux_div = readl(ri->reg_clk_ctrl);
        else
                mux_div = readl(ri->reg_clk_sel);

        if (change_div) {
                width = ri->width_div;
                shift = ri->shift_div;
                mux_div &= ~MMP_CLK_BITS_MASK(width, shift);
                mux_div |= MMP_CLK_BITS_SET_VAL(div_val, width, shift);
        }

        if (change_mux) {
                width = ri->width_mux;
                shift = ri->shift_mux;
                mux_div &= ~MMP_CLK_BITS_MASK(width, shift);
                mux_div |= MMP_CLK_BITS_SET_VAL(mux_val, width, shift);
        }

        if (mix->type == MMP_CLK_MIX_TYPE_V1) {
                writel(mux_div, ri->reg_clk_ctrl);
        } else if (mix->type == MMP_CLK_MIX_TYPE_V2) {
                mux_div |= (1 << ri->bit_fc);
                writel(mux_div, ri->reg_clk_ctrl);

                do {
                        fc_req = readl(ri->reg_clk_ctrl);
                        timeout--;
                        if (!(fc_req & (1 << ri->bit_fc)))
                                break;
                } while (timeout);

                if (timeout == 0) {
                        pr_err("%s:%s cannot do frequency change\n",
                                __func__, clk_hw_get_name(&mix->hw));
                        ret = -EBUSY;
                        goto error;
                }
        } else {
                fc_req = readl(ri->reg_clk_ctrl);
                fc_req |= 1 << ri->bit_fc;
                writel(fc_req, ri->reg_clk_ctrl);
                writel(mux_div, ri->reg_clk_sel);
                fc_req &= ~(1 << ri->bit_fc);
        }

        ret = 0;
error:
        if (mix->lock)
                spin_unlock_irqrestore(mix->lock, flags);

        return ret;
}

static int mmp_clk_mix_determine_rate(struct clk_hw *hw,
                                      struct clk_rate_request *req)
{
        struct mmp_clk_mix *mix = to_clk_mix(hw);
        struct mmp_clk_mix_clk_table *item;
        struct clk_hw *parent, *parent_best;
        unsigned long parent_rate, mix_rate, mix_rate_best, parent_rate_best;
        unsigned long gap, gap_best;
        u32 div_val_max;
        unsigned int div;
        int i, j;


        mix_rate_best = 0;
        parent_rate_best = 0;
        gap_best = ULONG_MAX;
        parent_best = NULL;

        if (mix->table) {
                for (i = 0; i < mix->table_size; i++) {
                        item = &mix->table[i];
                        if (item->valid == 0)
                                continue;
                        parent = clk_hw_get_parent_by_index(hw,
                                                        item->parent_index);
                        parent_rate = clk_hw_get_rate(parent);
                        mix_rate = parent_rate / item->divisor;
                        gap = abs(mix_rate - req->rate);
                        if (!parent_best || gap < gap_best) {
                                parent_best = parent;
                                parent_rate_best = parent_rate;
                                mix_rate_best = mix_rate;
                                gap_best = gap;
                                if (gap_best == 0)
                                        goto found;
                        }
                }
        } else {
                for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
                        parent = clk_hw_get_parent_by_index(hw, i);
                        parent_rate = clk_hw_get_rate(parent);
                        div_val_max = _get_maxdiv(mix);
                        for (j = 0; j < div_val_max; j++) {
                                div = _get_div(mix, j);
                                mix_rate = parent_rate / div;
                                gap = abs(mix_rate - req->rate);
                                if (!parent_best || gap < gap_best) {
                                        parent_best = parent;
                                        parent_rate_best = parent_rate;
                                        mix_rate_best = mix_rate;
                                        gap_best = gap;
                                        if (gap_best == 0)
                                                goto found;
                                }
                        }
                }
        }

found:
        if (!parent_best)
                return -EINVAL;

        req->best_parent_rate = parent_rate_best;
        req->best_parent_hw = parent_best;
        req->rate = mix_rate_best;

        return 0;
}

static int mmp_clk_mix_set_rate_and_parent(struct clk_hw *hw,
                                                unsigned long rate,
                                                unsigned long parent_rate,
                                                u8 index)
{
        struct mmp_clk_mix *mix = to_clk_mix(hw);
        unsigned int div;
        u32 div_val, mux_val;

        div = parent_rate / rate;
        div_val = _get_div_val(mix, div);
        mux_val = _get_mux_val(mix, index);

        return _set_rate(mix, mux_val, div_val, 1, 1);
}

static u8 mmp_clk_mix_get_parent(struct clk_hw *hw)
{
        struct mmp_clk_mix *mix = to_clk_mix(hw);
        struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
        unsigned long flags = 0;
        u32 mux_div = 0;
        u8 width, shift;
        u32 mux_val;

        if (mix->lock)
                spin_lock_irqsave(mix->lock, flags);

        if (mix->type == MMP_CLK_MIX_TYPE_V1
                || mix->type == MMP_CLK_MIX_TYPE_V2)
                mux_div = readl(ri->reg_clk_ctrl);
        else
                mux_div = readl(ri->reg_clk_sel);

        if (mix->lock)
                spin_unlock_irqrestore(mix->lock, flags);

        width = mix->reg_info.width_mux;
        shift = mix->reg_info.shift_mux;

        mux_val = MMP_CLK_BITS_GET_VAL(mux_div, width, shift);

        return _get_mux(mix, mux_val);
}

static unsigned long mmp_clk_mix_recalc_rate(struct clk_hw *hw,
                                        unsigned long parent_rate)
{
        struct mmp_clk_mix *mix = to_clk_mix(hw);
        struct mmp_clk_mix_reg_info *ri = &mix->reg_info;
        unsigned long flags = 0;
        u32 mux_div = 0;
        u8 width, shift;
        unsigned int div;

        if (mix->lock)
                spin_lock_irqsave(mix->lock, flags);

        if (mix->type == MMP_CLK_MIX_TYPE_V1
                || mix->type == MMP_CLK_MIX_TYPE_V2)
                mux_div = readl(ri->reg_clk_ctrl);
        else
                mux_div = readl(ri->reg_clk_sel);

        if (mix->lock)
                spin_unlock_irqrestore(mix->lock, flags);

        width = mix->reg_info.width_div;
        shift = mix->reg_info.shift_div;

        div = _get_div(mix, MMP_CLK_BITS_GET_VAL(mux_div, width, shift));

        return parent_rate / div;
}

static int mmp_clk_set_parent(struct clk_hw *hw, u8 index)
{
        struct mmp_clk_mix *mix = to_clk_mix(hw);
        struct mmp_clk_mix_clk_table *item;
        int i;
        u32 div_val, mux_val;

        if (mix->table) {
                for (i = 0; i < mix->table_size; i++) {
                        item = &mix->table[i];
                        if (item->valid == 0)
                                continue;
                        if (item->parent_index == index)
                                break;
                }
                if (i < mix->table_size) {
                        div_val = _get_div_val(mix, item->divisor);
                        mux_val = _get_mux_val(mix, item->parent_index);
                } else
                        return -EINVAL;
        } else {
                mux_val = _get_mux_val(mix, index);
                div_val = 0;
        }

        return _set_rate(mix, mux_val, div_val, 1, div_val ? 1 : 0);
}

static int mmp_clk_set_rate(struct clk_hw *hw, unsigned long rate,
                                unsigned long best_parent_rate)
{
        struct mmp_clk_mix *mix = to_clk_mix(hw);
        struct mmp_clk_mix_clk_table *item;
        unsigned long parent_rate;
        unsigned int best_divisor;
        struct clk_hw *parent;
        int i;

        best_divisor = best_parent_rate / rate;

        if (mix->table) {
                for (i = 0; i < mix->table_size; i++) {
                        item = &mix->table[i];
                        if (item->valid == 0)
                                continue;
                        parent = clk_hw_get_parent_by_index(hw,
                                                        item->parent_index);
                        parent_rate = clk_hw_get_rate(parent);
                        if (parent_rate == best_parent_rate
                                && item->divisor == best_divisor)
                                break;
                }
                if (i < mix->table_size)
                        return _set_rate(mix,
                                        _get_mux_val(mix, item->parent_index),
                                        _get_div_val(mix, item->divisor),
                                        1, 1);
                else
                        return -EINVAL;
        } else {
                for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
                        parent = clk_hw_get_parent_by_index(hw, i);
                        parent_rate = clk_hw_get_rate(parent);
                        if (parent_rate == best_parent_rate)
                                break;
                }
                if (i < clk_hw_get_num_parents(hw))
                        return _set_rate(mix, _get_mux_val(mix, i),
                                        _get_div_val(mix, best_divisor), 1, 1);
                else
                        return -EINVAL;
        }
}

static int mmp_clk_mix_init(struct clk_hw *hw)
{
        struct mmp_clk_mix *mix = to_clk_mix(hw);

        if (mix->table)
                _filter_clk_table(mix, mix->table, mix->table_size);

        return 0;
}

const struct clk_ops mmp_clk_mix_ops = {
        .determine_rate = mmp_clk_mix_determine_rate,
        .set_rate_and_parent = mmp_clk_mix_set_rate_and_parent,
        .set_rate = mmp_clk_set_rate,
        .set_parent = mmp_clk_set_parent,
        .get_parent = mmp_clk_mix_get_parent,
        .recalc_rate = mmp_clk_mix_recalc_rate,
        .init = mmp_clk_mix_init,
};

struct clk *mmp_clk_register_mix(struct device *dev,
                                        const char *name,
                                        const char * const *parent_names,
                                        u8 num_parents,
                                        unsigned long flags,
                                        struct mmp_clk_mix_config *config,
                                        spinlock_t *lock)
{
        struct mmp_clk_mix *mix;
        struct clk *clk;
        struct clk_init_data init;

        mix = kzalloc_obj(*mix);
        if (!mix)
                return ERR_PTR(-ENOMEM);

        init.name = name;
        init.flags = flags | CLK_GET_RATE_NOCACHE;
        init.parent_names = parent_names;
        init.num_parents = num_parents;
        init.ops = &mmp_clk_mix_ops;

        memcpy(&mix->reg_info, &config->reg_info, sizeof(config->reg_info));
        if (config->table) {
                mix->table = kmemdup_array(config->table, config->table_size,
                                           sizeof(*mix->table), GFP_KERNEL);
                if (!mix->table)
                        goto free_mix;

                mix->table_size = config->table_size;
        }

        if (config->mux_table) {
                mix->mux_table = kmemdup_array(config->mux_table, num_parents,
                                               sizeof(*mix->mux_table), GFP_KERNEL);
                if (!mix->mux_table) {
                        kfree(mix->table);
                        goto free_mix;
                }
        }

        mix->div_flags = config->div_flags;
        mix->mux_flags = config->mux_flags;
        mix->lock = lock;
        mix->hw.init = &init;

        if (config->reg_info.bit_fc >= 32)
                mix->type = MMP_CLK_MIX_TYPE_V1;
        else if (config->reg_info.reg_clk_sel)
                mix->type = MMP_CLK_MIX_TYPE_V3;
        else
                mix->type = MMP_CLK_MIX_TYPE_V2;
        clk = clk_register(dev, &mix->hw);

        if (IS_ERR(clk)) {
                kfree(mix->mux_table);
                kfree(mix->table);
                kfree(mix);
        }

        return clk;

free_mix:
        kfree(mix);
        return ERR_PTR(-ENOMEM);
}