// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2019
 * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
 *
 * Common Clock Framework [CCF] driver for Sandbox
 */

#include <common.h>
#include <dm.h>
#include <clk.h>
#include <malloc.h>
#include <asm/clk.h>
#include <clk-uclass.h>
#include <dm/devres.h>
#include <linux/bitops.h>
#include <linux/clk-provider.h>
#include <sandbox-clk.h>
#include <linux/err.h>

/*
 * Sandbox implementation of CCF primitives necessary for clk-uclass testing
 *
 * --- Sandbox PLLv3 ---
 */
struct clk_pllv3 {
        struct clk      clk;
        u32             div_mask;
        u32             div_shift;
};

int sandbox_clk_enable_count(struct clk *clk)
{
        struct clk *clkp = NULL;
        int ret;

        ret = clk_get_by_id(clk->id, &clkp);
        if (ret)
                return 0;

        return clkp->enable_count;
}

static ulong clk_pllv3_get_rate(struct clk *clk)
{
        unsigned long parent_rate = clk_get_parent_rate(clk);

        return parent_rate * 24;
}

static const struct clk_ops clk_pllv3_generic_ops = {
        .get_rate       = clk_pllv3_get_rate,
};

struct clk *sandbox_clk_pllv3(enum sandbox_pllv3_type type, const char *name,
                              const char *parent_name, void __iomem *base,
                              u32 div_mask)
{
        struct clk_pllv3 *pll;
        struct clk *clk;
        char *drv_name = "sandbox_clk_pllv3";
        int ret;

        pll = kzalloc(sizeof(*pll), GFP_KERNEL);
        if (!pll)
                return ERR_PTR(-ENOMEM);

        pll->div_mask = div_mask;
        clk = &pll->clk;

        ret = clk_register(clk, drv_name, name, parent_name);
        if (ret) {
                kfree(pll);
                return ERR_PTR(ret);
        }

        return clk;
}

U_BOOT_DRIVER(sandbox_clk_pll_generic) = {
        .name   = "sandbox_clk_pllv3",
        .id     = UCLASS_CLK,
        .ops    = &clk_pllv3_generic_ops,
};

/* --- Sandbox PLLv3 --- */
/* --- Sandbox Gate  --- */
struct clk_gate2 {
        struct clk clk;
        bool    state;
};

#define to_clk_gate2(_clk) container_of(_clk, struct clk_gate2, clk)

static int clk_gate2_enable(struct clk *clk)
{
        struct clk_gate2 *gate = to_clk_gate2(dev_get_clk_ptr(clk->dev));

        gate->state = 1;
        return 0;
}

static int clk_gate2_disable(struct clk *clk)
{
        struct clk_gate2 *gate = to_clk_gate2(dev_get_clk_ptr(clk->dev));

        gate->state = 0;
        return 0;
}

static const struct clk_ops clk_gate2_ops = {
        .enable = clk_gate2_enable,
        .disable = clk_gate2_disable,
        .get_rate = clk_generic_get_rate,
};

struct clk *sandbox_clk_register_gate2(struct device *dev, const char *name,
                                       const char *parent_name,
                                       unsigned long flags, void __iomem *reg,
                                       u8 bit_idx, u8 cgr_val,
                                       u8 clk_gate2_flags)
{
        struct clk_gate2 *gate;
        struct clk *clk;
        int ret;

        gate = kzalloc(sizeof(*gate), GFP_KERNEL);
        if (!gate)
                return ERR_PTR(-ENOMEM);

        gate->state = 0;
        clk = &gate->clk;

        ret = clk_register(clk, "sandbox_clk_gate2", name, parent_name);
        if (ret) {
                kfree(gate);
                return ERR_PTR(ret);
        }

        return clk;
}

U_BOOT_DRIVER(sandbox_clk_gate2) = {
        .name   = "sandbox_clk_gate2",
        .id     = UCLASS_CLK,
        .ops    = &clk_gate2_ops,
};

static unsigned long sandbox_clk_composite_divider_recalc_rate(struct clk *clk)
{
        struct clk_divider *divider = (struct clk_divider *)to_clk_divider(clk);
        struct clk_composite *composite = (struct clk_composite *)clk->data;
        ulong parent_rate = clk_get_parent_rate(&composite->clk);
        unsigned int val;

        val = divider->io_divider_val;
        val >>= divider->shift;
        val &= clk_div_mask(divider->width);

        return divider_recalc_rate(clk, parent_rate, val, divider->table,
                                   divider->flags, divider->width);
}

static const struct clk_ops sandbox_clk_composite_divider_ops = {
        .get_rate = sandbox_clk_composite_divider_recalc_rate,
};

struct clk *sandbox_clk_composite(const char *name,
                                  const char * const *parent_names,
                                  int num_parents, void __iomem *reg,
                                  unsigned long flags)
{
        struct clk *clk = ERR_PTR(-ENOMEM);
        struct clk_divider *div = NULL;
        struct clk_gate *gate = NULL;
        struct clk_mux *mux = NULL;

        mux = kzalloc(sizeof(*mux), GFP_KERNEL);
        if (!mux)
                goto fail;

        mux->reg = reg;
        mux->shift = 24;
        mux->mask = 0x7;
        mux->num_parents = num_parents;
        mux->flags = flags;
        mux->parent_names = parent_names;

        div = kzalloc(sizeof(*div), GFP_KERNEL);
        if (!div)
                goto fail;

        div->reg = reg;
        div->shift = 16;
        div->width = 3;
        div->flags = CLK_DIVIDER_ROUND_CLOSEST | flags;

        gate = kzalloc(sizeof(*gate), GFP_KERNEL);
        if (!gate)
                goto fail;

        gate->reg = reg;
        gate->bit_idx = 28;
        gate->flags = flags;

        clk = clk_register_composite(NULL, name,
                                     parent_names, num_parents,
                                     &mux->clk, &clk_mux_ops, &div->clk,
                                     &sandbox_clk_composite_divider_ops,
                                     &gate->clk, &clk_gate_ops, flags);
        if (IS_ERR(clk))
                goto fail;

        return clk;

fail:
        kfree(gate);
        kfree(div);
        kfree(mux);
        return ERR_CAST(clk);
}

/* --- Sandbox Gate --- */
/* The CCF core driver itself */
static const struct udevice_id sandbox_clk_ccf_test_ids[] = {
        { .compatible = "sandbox,clk-ccf" },
        { }
};

static const char *const usdhc_sels[] = { "pll3_60m", "pll3_80m", };
static const char *const i2c_sels[] = { "pll3_60m", "pll3_80m", };

static int sandbox_clk_ccf_probe(struct udevice *dev)
{
        void *base = NULL;
        u32 reg;

        clk_dm(SANDBOX_CLK_PLL3,
               sandbox_clk_pllv3(SANDBOX_PLLV3_USB, "pll3_usb_otg", "osc",
                                 base + 0x10, 0x3));

        clk_dm(SANDBOX_CLK_PLL3_60M,
               sandbox_clk_fixed_factor("pll3_60m",  "pll3_usb_otg",   1, 8));

        clk_dm(SANDBOX_CLK_PLL3_80M,
               sandbox_clk_fixed_factor("pll3_80m",  "pll3_usb_otg",   1, 6));

        /* The HW adds +1 to the divider value (2+1) is the divider */
        reg = (2 << 19);
        clk_dm(SANDBOX_CLK_ECSPI_ROOT,
               sandbox_clk_divider("ecspi_root", "pll3_60m", &reg, 19, 6));

        clk_dm(SANDBOX_CLK_ECSPI1,
               sandbox_clk_gate2("ecspi1", "ecspi_root", base + 0x6c, 0));

        /* Select 'pll3_60m' */
        reg = 0;
        clk_dm(SANDBOX_CLK_USDHC1_SEL,
               sandbox_clk_mux("usdhc1_sel", &reg, 16, 1, usdhc_sels,
                               ARRAY_SIZE(usdhc_sels)));

        /* Select 'pll3_80m' */
        reg = BIT(17);
        clk_dm(SANDBOX_CLK_USDHC2_SEL,
               sandbox_clk_mux("usdhc2_sel", &reg, 17, 1, usdhc_sels,
                               ARRAY_SIZE(usdhc_sels)));

        reg = BIT(28) | BIT(24) | BIT(16);
        clk_dm(SANDBOX_CLK_I2C,
               sandbox_clk_composite("i2c", i2c_sels, ARRAY_SIZE(i2c_sels),
                                     &reg, 0));

        clk_dm(SANDBOX_CLK_I2C_ROOT,
               sandbox_clk_gate2("i2c_root", "i2c", base + 0x7c, 0));

        return 0;
}

U_BOOT_DRIVER(sandbox_clk_ccf) = {
        .name = "sandbox_clk_ccf",
        .id = UCLASS_CLK,
        .probe = sandbox_clk_ccf_probe,
        .of_match = sandbox_clk_ccf_test_ids,
};