root/drivers/clk/imx/clk-composite-93.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright 2021 NXP
 *
 * Peng Fan <peng.fan@nxp.com>
 */

#include <linux/clk-provider.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/slab.h>

#include "clk.h"

#define TIMEOUT_US      500U

#define CCM_DIV_SHIFT   0
#define CCM_DIV_WIDTH   8
#define CCM_MUX_SHIFT   8
#define CCM_MUX_MASK    3
#define CCM_OFF_SHIFT   24
#define CCM_BUSY_SHIFT  28

#define STAT_OFFSET     0x4
#define AUTHEN_OFFSET   0x30
#define TZ_NS_SHIFT     9
#define TZ_NS_MASK      BIT(9)

#define WHITE_LIST_SHIFT        16

static int imx93_clk_composite_wait_ready(struct clk_hw *hw, void __iomem *reg)
{
        int ret;
        u32 val;

        ret = readl_poll_timeout_atomic(reg + STAT_OFFSET, val, !(val & BIT(CCM_BUSY_SHIFT)),
                                        0, TIMEOUT_US);
        if (ret)
                pr_err("Slice[%s] busy timeout\n", clk_hw_get_name(hw));

        return ret;
}

static void imx93_clk_composite_gate_endisable(struct clk_hw *hw, int enable)
{
        struct clk_gate *gate = to_clk_gate(hw);
        unsigned long flags;
        u32 reg;

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

        reg = readl(gate->reg);

        if (enable)
                reg &= ~BIT(gate->bit_idx);
        else
                reg |= BIT(gate->bit_idx);

        writel(reg, gate->reg);

        imx93_clk_composite_wait_ready(hw, gate->reg);

        if (gate->lock)
                spin_unlock_irqrestore(gate->lock, flags);
}

static int imx93_clk_composite_gate_enable(struct clk_hw *hw)
{
        imx93_clk_composite_gate_endisable(hw, 1);

        return 0;
}

static void imx93_clk_composite_gate_disable(struct clk_hw *hw)
{
        /*
         * Skip disable the root clock gate if mcore enabled.
         * The root clock may be used by the mcore.
         */
        if (mcore_booted)
                return;

        imx93_clk_composite_gate_endisable(hw, 0);
}

static const struct clk_ops imx93_clk_composite_gate_ops = {
        .enable = imx93_clk_composite_gate_enable,
        .disable = imx93_clk_composite_gate_disable,
        .is_enabled = clk_gate_is_enabled,
};

static unsigned long
imx93_clk_composite_divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
{
        return clk_divider_ops.recalc_rate(hw, parent_rate);
}

static int
imx93_clk_composite_divider_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
{
        return clk_divider_ops.determine_rate(hw, req);
}

static int imx93_clk_composite_divider_set_rate(struct clk_hw *hw, unsigned long rate,
                                                unsigned long parent_rate)
{
        struct clk_divider *divider = to_clk_divider(hw);
        int value;
        unsigned long flags = 0;
        u32 val;
        int ret;

        value = divider_get_val(rate, parent_rate, divider->table, divider->width, divider->flags);
        if (value < 0)
                return value;

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

        val = readl(divider->reg);
        val &= ~(clk_div_mask(divider->width) << divider->shift);
        val |= (u32)value << divider->shift;
        writel(val, divider->reg);

        ret = imx93_clk_composite_wait_ready(hw, divider->reg);

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

        return ret;
}

static const struct clk_ops imx93_clk_composite_divider_ops = {
        .recalc_rate = imx93_clk_composite_divider_recalc_rate,
        .determine_rate = imx93_clk_composite_divider_determine_rate,
        .set_rate = imx93_clk_composite_divider_set_rate,
};

static u8 imx93_clk_composite_mux_get_parent(struct clk_hw *hw)
{
        return clk_mux_ops.get_parent(hw);
}

static int imx93_clk_composite_mux_set_parent(struct clk_hw *hw, u8 index)
{
        struct clk_mux *mux = to_clk_mux(hw);
        u32 val = clk_mux_index_to_val(mux->table, mux->flags, index);
        unsigned long flags = 0;
        u32 reg;
        int ret;

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

        reg = readl(mux->reg);
        reg &= ~(mux->mask << mux->shift);
        val = val << mux->shift;
        reg |= val;
        writel(reg, mux->reg);

        ret = imx93_clk_composite_wait_ready(hw, mux->reg);

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

        return ret;
}

static int
imx93_clk_composite_mux_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
{
        return clk_mux_ops.determine_rate(hw, req);
}

static const struct clk_ops imx93_clk_composite_mux_ops = {
        .get_parent = imx93_clk_composite_mux_get_parent,
        .set_parent = imx93_clk_composite_mux_set_parent,
        .determine_rate = imx93_clk_composite_mux_determine_rate,
};

struct clk_hw *imx93_clk_composite_flags(const char *name, const char * const *parent_names,
                                         int num_parents, void __iomem *reg, u32 domain_id,
                                         unsigned long flags)
{
        struct clk_hw *hw = ERR_PTR(-ENOMEM), *mux_hw;
        struct clk_hw *div_hw, *gate_hw;
        struct clk_divider *div = NULL;
        struct clk_gate *gate = NULL;
        struct clk_mux *mux = NULL;
        bool clk_ro = false;
        u32 authen;

        mux = kzalloc_obj(*mux);
        if (!mux)
                goto fail;

        mux_hw = &mux->hw;
        mux->reg = reg;
        mux->shift = CCM_MUX_SHIFT;
        mux->mask = CCM_MUX_MASK;
        mux->lock = &imx_ccm_lock;

        div = kzalloc_obj(*div);
        if (!div)
                goto fail;

        div_hw = &div->hw;
        div->reg = reg;
        div->shift = CCM_DIV_SHIFT;
        div->width = CCM_DIV_WIDTH;
        div->lock = &imx_ccm_lock;
        div->flags = CLK_DIVIDER_ROUND_CLOSEST;

        authen = readl(reg + AUTHEN_OFFSET);
        if (!(authen & TZ_NS_MASK) || !(authen & BIT(WHITE_LIST_SHIFT + domain_id)))
                clk_ro = true;

        if (clk_ro) {
                hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
                                               mux_hw, &clk_mux_ro_ops, div_hw,
                                               &clk_divider_ro_ops, NULL, NULL, flags);
        } else {
                gate = kzalloc_obj(*gate);
                if (!gate)
                        goto fail;

                gate_hw = &gate->hw;
                gate->reg = reg;
                gate->bit_idx = CCM_OFF_SHIFT;
                gate->lock = &imx_ccm_lock;
                gate->flags = CLK_GATE_SET_TO_DISABLE;

                hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
                                               mux_hw, &imx93_clk_composite_mux_ops, div_hw,
                                               &imx93_clk_composite_divider_ops, gate_hw,
                                               &imx93_clk_composite_gate_ops,
                                               flags | CLK_SET_RATE_NO_REPARENT);
        }

        if (IS_ERR(hw))
                goto fail;

        return hw;

fail:
        kfree(gate);
        kfree(div);
        kfree(mux);
        return ERR_CAST(hw);
}
EXPORT_SYMBOL_GPL(imx93_clk_composite_flags);