// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2019-20 Sean Anderson <seanga2@gmail.com>
 * Copyright (c) 2019 Western Digital Corporation or its affiliates.
 */
#define pr_fmt(fmt)     "k210-clk: " fmt

#include <linux/io.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_clk.h>
#include <linux/of_address.h>
#include <linux/clk-provider.h>
#include <linux/bitfield.h>
#include <linux/delay.h>
#include <soc/canaan/k210-sysctl.h>

#include <dt-bindings/clock/k210-clk.h>

struct k210_sysclk;

struct k210_clk {
        int id;
        struct k210_sysclk *ksc;
        struct clk_hw hw;
};

struct k210_clk_cfg {
        const char *name;
        u8 gate_reg;
        u8 gate_bit;
        u8 div_reg;
        u8 div_shift;
        u8 div_width;
        u8 div_type;
        u8 mux_reg;
        u8 mux_bit;
};

enum k210_clk_div_type {
        K210_DIV_NONE,
        K210_DIV_ONE_BASED,
        K210_DIV_DOUBLE_ONE_BASED,
        K210_DIV_POWER_OF_TWO,
};

#define K210_GATE(_reg, _bit)   \
        .gate_reg = (_reg),     \
        .gate_bit = (_bit)

#define K210_DIV(_reg, _shift, _width, _type)   \
        .div_reg = (_reg),                      \
        .div_shift = (_shift),                  \
        .div_width = (_width),                  \
        .div_type = (_type)

#define K210_MUX(_reg, _bit)    \
        .mux_reg = (_reg),      \
        .mux_bit = (_bit)

static struct k210_clk_cfg k210_clk_cfgs[K210_NUM_CLKS] = {
        /* Gated clocks, no mux, no divider */
        [K210_CLK_CPU] = {
                .name = "cpu",
                K210_GATE(K210_SYSCTL_EN_CENT, 0)
        },
        [K210_CLK_DMA] = {
                .name = "dma",
                K210_GATE(K210_SYSCTL_EN_PERI, 1)
        },
        [K210_CLK_FFT] = {
                .name = "fft",
                K210_GATE(K210_SYSCTL_EN_PERI, 4)
        },
        [K210_CLK_GPIO] = {
                .name = "gpio",
                K210_GATE(K210_SYSCTL_EN_PERI, 5)
        },
        [K210_CLK_UART1] = {
                .name = "uart1",
                K210_GATE(K210_SYSCTL_EN_PERI, 16)
        },
        [K210_CLK_UART2] = {
                .name = "uart2",
                K210_GATE(K210_SYSCTL_EN_PERI, 17)
        },
        [K210_CLK_UART3] = {
                .name = "uart3",
                K210_GATE(K210_SYSCTL_EN_PERI, 18)
        },
        [K210_CLK_FPIOA] = {
                .name = "fpioa",
                K210_GATE(K210_SYSCTL_EN_PERI, 20)
        },
        [K210_CLK_SHA] = {
                .name = "sha",
                K210_GATE(K210_SYSCTL_EN_PERI, 26)
        },
        [K210_CLK_AES] = {
                .name = "aes",
                K210_GATE(K210_SYSCTL_EN_PERI, 19)
        },
        [K210_CLK_OTP] = {
                .name = "otp",
                K210_GATE(K210_SYSCTL_EN_PERI, 27)
        },
        [K210_CLK_RTC] = {
                .name = "rtc",
                K210_GATE(K210_SYSCTL_EN_PERI, 29)
        },

        /* Gated divider clocks */
        [K210_CLK_SRAM0] = {
                .name = "sram0",
                K210_GATE(K210_SYSCTL_EN_CENT, 1),
                K210_DIV(K210_SYSCTL_THR0, 0, 4, K210_DIV_ONE_BASED)
        },
        [K210_CLK_SRAM1] = {
                .name = "sram1",
                K210_GATE(K210_SYSCTL_EN_CENT, 2),
                K210_DIV(K210_SYSCTL_THR0, 4, 4, K210_DIV_ONE_BASED)
        },
        [K210_CLK_ROM] = {
                .name = "rom",
                K210_GATE(K210_SYSCTL_EN_PERI, 0),
                K210_DIV(K210_SYSCTL_THR0, 16, 4, K210_DIV_ONE_BASED)
        },
        [K210_CLK_DVP] = {
                .name = "dvp",
                K210_GATE(K210_SYSCTL_EN_PERI, 3),
                K210_DIV(K210_SYSCTL_THR0, 12, 4, K210_DIV_ONE_BASED)
        },
        [K210_CLK_APB0] = {
                .name = "apb0",
                K210_GATE(K210_SYSCTL_EN_CENT, 3),
                K210_DIV(K210_SYSCTL_SEL0, 3, 3, K210_DIV_ONE_BASED)
        },
        [K210_CLK_APB1] = {
                .name = "apb1",
                K210_GATE(K210_SYSCTL_EN_CENT, 4),
                K210_DIV(K210_SYSCTL_SEL0, 6, 3, K210_DIV_ONE_BASED)
        },
        [K210_CLK_APB2] = {
                .name = "apb2",
                K210_GATE(K210_SYSCTL_EN_CENT, 5),
                K210_DIV(K210_SYSCTL_SEL0, 9, 3, K210_DIV_ONE_BASED)
        },
        [K210_CLK_AI] = {
                .name = "ai",
                K210_GATE(K210_SYSCTL_EN_PERI, 2),
                K210_DIV(K210_SYSCTL_THR0, 8, 4, K210_DIV_ONE_BASED)
        },
        [K210_CLK_SPI0] = {
                .name = "spi0",
                K210_GATE(K210_SYSCTL_EN_PERI, 6),
                K210_DIV(K210_SYSCTL_THR1, 0, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_SPI1] = {
                .name = "spi1",
                K210_GATE(K210_SYSCTL_EN_PERI, 7),
                K210_DIV(K210_SYSCTL_THR1, 8, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_SPI2] = {
                .name = "spi2",
                K210_GATE(K210_SYSCTL_EN_PERI, 8),
                K210_DIV(K210_SYSCTL_THR1, 16, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_I2C0] = {
                .name = "i2c0",
                K210_GATE(K210_SYSCTL_EN_PERI, 13),
                K210_DIV(K210_SYSCTL_THR5, 8, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_I2C1] = {
                .name = "i2c1",
                K210_GATE(K210_SYSCTL_EN_PERI, 14),
                K210_DIV(K210_SYSCTL_THR5, 16, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_I2C2] = {
                .name = "i2c2",
                K210_GATE(K210_SYSCTL_EN_PERI, 15),
                K210_DIV(K210_SYSCTL_THR5, 24, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_WDT0] = {
                .name = "wdt0",
                K210_GATE(K210_SYSCTL_EN_PERI, 24),
                K210_DIV(K210_SYSCTL_THR6, 0, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_WDT1] = {
                .name = "wdt1",
                K210_GATE(K210_SYSCTL_EN_PERI, 25),
                K210_DIV(K210_SYSCTL_THR6, 8, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_I2S0] = {
                .name = "i2s0",
                K210_GATE(K210_SYSCTL_EN_PERI, 10),
                K210_DIV(K210_SYSCTL_THR3, 0, 16, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_I2S1] = {
                .name = "i2s1",
                K210_GATE(K210_SYSCTL_EN_PERI, 11),
                K210_DIV(K210_SYSCTL_THR3, 16, 16, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_I2S2] = {
                .name = "i2s2",
                K210_GATE(K210_SYSCTL_EN_PERI, 12),
                K210_DIV(K210_SYSCTL_THR4, 0, 16, K210_DIV_DOUBLE_ONE_BASED)
        },

        /* Divider clocks, no gate, no mux */
        [K210_CLK_I2S0_M] = {
                .name = "i2s0_m",
                K210_DIV(K210_SYSCTL_THR4, 16, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_I2S1_M] = {
                .name = "i2s1_m",
                K210_DIV(K210_SYSCTL_THR4, 24, 8, K210_DIV_DOUBLE_ONE_BASED)
        },
        [K210_CLK_I2S2_M] = {
                .name = "i2s2_m",
                K210_DIV(K210_SYSCTL_THR4, 0, 8, K210_DIV_DOUBLE_ONE_BASED)
        },

        /* Muxed gated divider clocks */
        [K210_CLK_SPI3] = {
                .name = "spi3",
                K210_GATE(K210_SYSCTL_EN_PERI, 9),
                K210_DIV(K210_SYSCTL_THR1, 24, 8, K210_DIV_DOUBLE_ONE_BASED),
                K210_MUX(K210_SYSCTL_SEL0, 12)
        },
        [K210_CLK_TIMER0] = {
                .name = "timer0",
                K210_GATE(K210_SYSCTL_EN_PERI, 21),
                K210_DIV(K210_SYSCTL_THR2,  0, 8, K210_DIV_DOUBLE_ONE_BASED),
                K210_MUX(K210_SYSCTL_SEL0, 13)
        },
        [K210_CLK_TIMER1] = {
                .name = "timer1",
                K210_GATE(K210_SYSCTL_EN_PERI, 22),
                K210_DIV(K210_SYSCTL_THR2, 8, 8, K210_DIV_DOUBLE_ONE_BASED),
                K210_MUX(K210_SYSCTL_SEL0, 14)
        },
        [K210_CLK_TIMER2] = {
                .name = "timer2",
                K210_GATE(K210_SYSCTL_EN_PERI, 23),
                K210_DIV(K210_SYSCTL_THR2, 16, 8, K210_DIV_DOUBLE_ONE_BASED),
                K210_MUX(K210_SYSCTL_SEL0, 15)
        },
};

/*
 * PLL control register bits.
 */
#define K210_PLL_CLKR           GENMASK(3, 0)
#define K210_PLL_CLKF           GENMASK(9, 4)
#define K210_PLL_CLKOD          GENMASK(13, 10)
#define K210_PLL_BWADJ          GENMASK(19, 14)
#define K210_PLL_RESET          (1 << 20)
#define K210_PLL_PWRD           (1 << 21)
#define K210_PLL_INTFB          (1 << 22)
#define K210_PLL_BYPASS         (1 << 23)
#define K210_PLL_TEST           (1 << 24)
#define K210_PLL_EN             (1 << 25)
#define K210_PLL_SEL            GENMASK(27, 26) /* PLL2 only */

/*
 * PLL lock register bits.
 */
#define K210_PLL_LOCK           0
#define K210_PLL_CLEAR_SLIP     2
#define K210_PLL_TEST_OUT       3

/*
 * Clock selector register bits.
 */
#define K210_ACLK_SEL           BIT(0)
#define K210_ACLK_DIV           GENMASK(2, 1)

/*
 * PLLs.
 */
enum k210_pll_id {
        K210_PLL0, K210_PLL1, K210_PLL2, K210_PLL_NUM
};

struct k210_pll {
        enum k210_pll_id id;
        struct k210_sysclk *ksc;
        void __iomem *base;
        void __iomem *reg;
        void __iomem *lock;
        u8 lock_shift;
        u8 lock_width;
        struct clk_hw hw;
};
#define to_k210_pll(_hw)        container_of(_hw, struct k210_pll, hw)

/*
 * PLLs configuration: by default PLL0 runs at 780 MHz and PLL1 at 299 MHz.
 * The first 2 SRAM banks depend on ACLK/CPU clock which is by default PLL0
 * rate divided by 2. Set PLL1 to 390 MHz so that the third SRAM bank has the
 * same clock as the first 2.
 */
struct k210_pll_cfg {
        u32 reg;
        u8 lock_shift;
        u8 lock_width;
        u32 r;
        u32 f;
        u32 od;
        u32 bwadj;
};

static struct k210_pll_cfg k210_plls_cfg[] = {
        { K210_SYSCTL_PLL0,  0, 2, 0, 59, 1, 59 }, /* 780 MHz */
        { K210_SYSCTL_PLL1,  8, 1, 0, 59, 3, 59 }, /* 390 MHz */
        { K210_SYSCTL_PLL2, 16, 1, 0, 22, 1, 22 }, /* 299 MHz */
};

/**
 * struct k210_sysclk - sysclk driver data
 * @regs: system controller registers start address
 * @clk_lock: clock setting spinlock
 * @plls: SoC PLLs descriptors
 * @aclk: ACLK clock
 * @clks: All other clocks
 */
struct k210_sysclk {
        void __iomem                    *regs;
        spinlock_t                      clk_lock;
        struct k210_pll                 plls[K210_PLL_NUM];
        struct clk_hw                   aclk;
        struct k210_clk                 clks[K210_NUM_CLKS];
};

#define to_k210_sysclk(_hw)     container_of(_hw, struct k210_sysclk, aclk)

/*
 * Set ACLK parent selector: 0 for IN0, 1 for PLL0.
 */
static void k210_aclk_set_selector(void __iomem *regs, u8 sel)
{
        u32 reg = readl(regs + K210_SYSCTL_SEL0);

        if (sel)
                reg |= K210_ACLK_SEL;
        else
                reg &= K210_ACLK_SEL;
        writel(reg, regs + K210_SYSCTL_SEL0);
}

static void k210_init_pll(void __iomem *regs, enum k210_pll_id pllid,
                          struct k210_pll *pll)
{
        pll->id = pllid;
        pll->reg = regs + k210_plls_cfg[pllid].reg;
        pll->lock = regs + K210_SYSCTL_PLL_LOCK;
        pll->lock_shift = k210_plls_cfg[pllid].lock_shift;
        pll->lock_width = k210_plls_cfg[pllid].lock_width;
}

static void k210_pll_wait_for_lock(struct k210_pll *pll)
{
        u32 reg, mask = GENMASK(pll->lock_shift + pll->lock_width - 1,
                                pll->lock_shift);

        while (true) {
                reg = readl(pll->lock);
                if ((reg & mask) == mask)
                        break;

                reg |= BIT(pll->lock_shift + K210_PLL_CLEAR_SLIP);
                writel(reg, pll->lock);
        }
}

static bool k210_pll_hw_is_enabled(struct k210_pll *pll)
{
        u32 reg = readl(pll->reg);
        u32 mask = K210_PLL_PWRD | K210_PLL_EN;

        if (reg & K210_PLL_RESET)
                return false;

        return (reg & mask) == mask;
}

static void k210_pll_enable_hw(void __iomem *regs, struct k210_pll *pll)
{
        struct k210_pll_cfg *pll_cfg = &k210_plls_cfg[pll->id];
        u32 reg;

        if (k210_pll_hw_is_enabled(pll))
                return;

        /*
         * For PLL0, we need to re-parent ACLK to IN0 to keep the CPU cores and
         * SRAM running.
         */
        if (pll->id == K210_PLL0)
                k210_aclk_set_selector(regs, 0);

        /* Set PLL factors */
        reg = readl(pll->reg);
        reg &= ~GENMASK(19, 0);
        reg |= FIELD_PREP(K210_PLL_CLKR, pll_cfg->r);
        reg |= FIELD_PREP(K210_PLL_CLKF, pll_cfg->f);
        reg |= FIELD_PREP(K210_PLL_CLKOD, pll_cfg->od);
        reg |= FIELD_PREP(K210_PLL_BWADJ, pll_cfg->bwadj);
        reg |= K210_PLL_PWRD;
        writel(reg, pll->reg);

        /*
         * Reset the PLL: ensure reset is low before asserting it.
         * The magic NOPs come from the Kendryte reference SDK.
         */
        reg &= ~K210_PLL_RESET;
        writel(reg, pll->reg);
        reg |= K210_PLL_RESET;
        writel(reg, pll->reg);
        nop();
        nop();
        reg &= ~K210_PLL_RESET;
        writel(reg, pll->reg);

        k210_pll_wait_for_lock(pll);

        reg &= ~K210_PLL_BYPASS;
        reg |= K210_PLL_EN;
        writel(reg, pll->reg);

        if (pll->id == K210_PLL0)
                k210_aclk_set_selector(regs, 1);
}

static int k210_pll_enable(struct clk_hw *hw)
{
        struct k210_pll *pll = to_k210_pll(hw);
        struct k210_sysclk *ksc = pll->ksc;
        unsigned long flags;

        spin_lock_irqsave(&ksc->clk_lock, flags);

        k210_pll_enable_hw(ksc->regs, pll);

        spin_unlock_irqrestore(&ksc->clk_lock, flags);

        return 0;
}

static void k210_pll_disable(struct clk_hw *hw)
{
        struct k210_pll *pll = to_k210_pll(hw);
        struct k210_sysclk *ksc = pll->ksc;
        unsigned long flags;
        u32 reg;

        /*
         * Bypassing before powering off is important so child clocks do not
         * stop working. This is especially important for pll0, the indirect
         * parent of the cpu clock.
         */
        spin_lock_irqsave(&ksc->clk_lock, flags);
        reg = readl(pll->reg);
        reg |= K210_PLL_BYPASS;
        writel(reg, pll->reg);

        reg &= ~K210_PLL_PWRD;
        reg &= ~K210_PLL_EN;
        writel(reg, pll->reg);
        spin_unlock_irqrestore(&ksc->clk_lock, flags);
}

static int k210_pll_is_enabled(struct clk_hw *hw)
{
        return k210_pll_hw_is_enabled(to_k210_pll(hw));
}

static unsigned long k210_pll_get_rate(struct clk_hw *hw,
                                       unsigned long parent_rate)
{
        struct k210_pll *pll = to_k210_pll(hw);
        u32 reg = readl(pll->reg);
        u32 r, f, od;

        if (reg & K210_PLL_BYPASS)
                return parent_rate;

        if (!(reg & K210_PLL_PWRD))
                return 0;

        r = FIELD_GET(K210_PLL_CLKR, reg) + 1;
        f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
        od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;

        return div_u64((u64)parent_rate * f, r * od);
}

static const struct clk_ops k210_pll_ops = {
        .enable         = k210_pll_enable,
        .disable        = k210_pll_disable,
        .is_enabled     = k210_pll_is_enabled,
        .recalc_rate    = k210_pll_get_rate,
};

static int k210_pll2_set_parent(struct clk_hw *hw, u8 index)
{
        struct k210_pll *pll = to_k210_pll(hw);
        struct k210_sysclk *ksc = pll->ksc;
        unsigned long flags;
        u32 reg;

        spin_lock_irqsave(&ksc->clk_lock, flags);

        reg = readl(pll->reg);
        reg &= ~K210_PLL_SEL;
        reg |= FIELD_PREP(K210_PLL_SEL, index);
        writel(reg, pll->reg);

        spin_unlock_irqrestore(&ksc->clk_lock, flags);

        return 0;
}

static u8 k210_pll2_get_parent(struct clk_hw *hw)
{
        struct k210_pll *pll = to_k210_pll(hw);
        u32 reg = readl(pll->reg);

        return FIELD_GET(K210_PLL_SEL, reg);
}

static const struct clk_ops k210_pll2_ops = {
        .enable         = k210_pll_enable,
        .disable        = k210_pll_disable,
        .is_enabled     = k210_pll_is_enabled,
        .recalc_rate    = k210_pll_get_rate,
        .determine_rate = clk_hw_determine_rate_no_reparent,
        .set_parent     = k210_pll2_set_parent,
        .get_parent     = k210_pll2_get_parent,
};

static int __init k210_register_pll(struct device_node *np,
                                    struct k210_sysclk *ksc,
                                    enum k210_pll_id pllid, const char *name,
                                    int num_parents, const struct clk_ops *ops)
{
        struct k210_pll *pll = &ksc->plls[pllid];
        struct clk_init_data init = {};
        const struct clk_parent_data parent_data[] = {
                { /* .index = 0 for in0 */ },
                { .hw = &ksc->plls[K210_PLL0].hw },
                { .hw = &ksc->plls[K210_PLL1].hw },
        };

        init.name = name;
        init.parent_data = parent_data;
        init.num_parents = num_parents;
        init.ops = ops;

        pll->hw.init = &init;
        pll->ksc = ksc;

        return of_clk_hw_register(np, &pll->hw);
}

static int __init k210_register_plls(struct device_node *np,
                                     struct k210_sysclk *ksc)
{
        int i, ret;

        for (i = 0; i < K210_PLL_NUM; i++)
                k210_init_pll(ksc->regs, i, &ksc->plls[i]);

        /* PLL0 and PLL1 only have IN0 as parent */
        ret = k210_register_pll(np, ksc, K210_PLL0, "pll0", 1, &k210_pll_ops);
        if (ret) {
                pr_err("%pOFP: register PLL0 failed\n", np);
                return ret;
        }
        ret = k210_register_pll(np, ksc, K210_PLL1, "pll1", 1, &k210_pll_ops);
        if (ret) {
                pr_err("%pOFP: register PLL1 failed\n", np);
                return ret;
        }

        /* PLL2 has IN0, PLL0 and PLL1 as parents */
        ret = k210_register_pll(np, ksc, K210_PLL2, "pll2", 3, &k210_pll2_ops);
        if (ret) {
                pr_err("%pOFP: register PLL2 failed\n", np);
                return ret;
        }

        return 0;
}

static int k210_aclk_set_parent(struct clk_hw *hw, u8 index)
{
        struct k210_sysclk *ksc = to_k210_sysclk(hw);
        unsigned long flags;

        spin_lock_irqsave(&ksc->clk_lock, flags);

        k210_aclk_set_selector(ksc->regs, index);

        spin_unlock_irqrestore(&ksc->clk_lock, flags);

        return 0;
}

static u8 k210_aclk_get_parent(struct clk_hw *hw)
{
        struct k210_sysclk *ksc = to_k210_sysclk(hw);
        u32 sel;

        sel = readl(ksc->regs + K210_SYSCTL_SEL0) & K210_ACLK_SEL;

        return sel ? 1 : 0;
}

static unsigned long k210_aclk_get_rate(struct clk_hw *hw,
                                        unsigned long parent_rate)
{
        struct k210_sysclk *ksc = to_k210_sysclk(hw);
        u32 reg = readl(ksc->regs + K210_SYSCTL_SEL0);
        unsigned int shift;

        if (!(reg & 0x1))
                return parent_rate;

        shift = FIELD_GET(K210_ACLK_DIV, reg);

        return parent_rate / (2UL << shift);
}

static const struct clk_ops k210_aclk_ops = {
        .determine_rate = clk_hw_determine_rate_no_reparent,
        .set_parent     = k210_aclk_set_parent,
        .get_parent     = k210_aclk_get_parent,
        .recalc_rate    = k210_aclk_get_rate,
};

/*
 * ACLK has IN0 and PLL0 as parents.
 */
static int __init k210_register_aclk(struct device_node *np,
                                     struct k210_sysclk *ksc)
{
        struct clk_init_data init = {};
        const struct clk_parent_data parent_data[] = {
                { /* .index = 0 for in0 */ },
                { .hw = &ksc->plls[K210_PLL0].hw },
        };
        int ret;

        init.name = "aclk";
        init.parent_data = parent_data;
        init.num_parents = 2;
        init.ops = &k210_aclk_ops;
        ksc->aclk.init = &init;

        ret = of_clk_hw_register(np, &ksc->aclk);
        if (ret) {
                pr_err("%pOFP: register aclk failed\n", np);
                return ret;
        }

        return 0;
}

#define to_k210_clk(_hw)        container_of(_hw, struct k210_clk, hw)

static int k210_clk_enable(struct clk_hw *hw)
{
        struct k210_clk *kclk = to_k210_clk(hw);
        struct k210_sysclk *ksc = kclk->ksc;
        struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
        unsigned long flags;
        u32 reg;

        if (!cfg->gate_reg)
                return 0;

        spin_lock_irqsave(&ksc->clk_lock, flags);
        reg = readl(ksc->regs + cfg->gate_reg);
        reg |= BIT(cfg->gate_bit);
        writel(reg, ksc->regs + cfg->gate_reg);
        spin_unlock_irqrestore(&ksc->clk_lock, flags);

        return 0;
}

static void k210_clk_disable(struct clk_hw *hw)
{
        struct k210_clk *kclk = to_k210_clk(hw);
        struct k210_sysclk *ksc = kclk->ksc;
        struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
        unsigned long flags;
        u32 reg;

        if (!cfg->gate_reg)
                return;

        spin_lock_irqsave(&ksc->clk_lock, flags);
        reg = readl(ksc->regs + cfg->gate_reg);
        reg &= ~BIT(cfg->gate_bit);
        writel(reg, ksc->regs + cfg->gate_reg);
        spin_unlock_irqrestore(&ksc->clk_lock, flags);
}

static int k210_clk_set_parent(struct clk_hw *hw, u8 index)
{
        struct k210_clk *kclk = to_k210_clk(hw);
        struct k210_sysclk *ksc = kclk->ksc;
        struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
        unsigned long flags;
        u32 reg;

        spin_lock_irqsave(&ksc->clk_lock, flags);
        reg = readl(ksc->regs + cfg->mux_reg);
        if (index)
                reg |= BIT(cfg->mux_bit);
        else
                reg &= ~BIT(cfg->mux_bit);
        writel(reg, ksc->regs + cfg->mux_reg);
        spin_unlock_irqrestore(&ksc->clk_lock, flags);

        return 0;
}

static u8 k210_clk_get_parent(struct clk_hw *hw)
{
        struct k210_clk *kclk = to_k210_clk(hw);
        struct k210_sysclk *ksc = kclk->ksc;
        struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
        unsigned long flags;
        u32 reg, idx;

        spin_lock_irqsave(&ksc->clk_lock, flags);
        reg = readl(ksc->regs + cfg->mux_reg);
        idx = (reg & BIT(cfg->mux_bit)) ? 1 : 0;
        spin_unlock_irqrestore(&ksc->clk_lock, flags);

        return idx;
}

static unsigned long k210_clk_get_rate(struct clk_hw *hw,
                                       unsigned long parent_rate)
{
        struct k210_clk *kclk = to_k210_clk(hw);
        struct k210_sysclk *ksc = kclk->ksc;
        struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
        u32 reg, div_val;

        if (!cfg->div_reg)
                return parent_rate;

        reg = readl(ksc->regs + cfg->div_reg);
        div_val = (reg >> cfg->div_shift) & GENMASK(cfg->div_width - 1, 0);

        switch (cfg->div_type) {
        case K210_DIV_ONE_BASED:
                return parent_rate / (div_val + 1);
        case K210_DIV_DOUBLE_ONE_BASED:
                return parent_rate / ((div_val + 1) * 2);
        case K210_DIV_POWER_OF_TWO:
                return parent_rate / (2UL << div_val);
        case K210_DIV_NONE:
        default:
                return 0;
        }
}

static const struct clk_ops k210_clk_mux_ops = {
        .enable         = k210_clk_enable,
        .disable        = k210_clk_disable,
        .determine_rate = clk_hw_determine_rate_no_reparent,
        .set_parent     = k210_clk_set_parent,
        .get_parent     = k210_clk_get_parent,
        .recalc_rate    = k210_clk_get_rate,
};

static const struct clk_ops k210_clk_ops = {
        .enable         = k210_clk_enable,
        .disable        = k210_clk_disable,
        .recalc_rate    = k210_clk_get_rate,
};

static void __init k210_register_clk(struct device_node *np,
                                     struct k210_sysclk *ksc, int id,
                                     const struct clk_parent_data *parent_data,
                                     int num_parents, unsigned long flags)
{
        struct k210_clk *kclk = &ksc->clks[id];
        struct clk_init_data init = {};
        int ret;

        init.name = k210_clk_cfgs[id].name;
        init.flags = flags;
        init.parent_data = parent_data;
        init.num_parents = num_parents;
        if (num_parents > 1)
                init.ops = &k210_clk_mux_ops;
        else
                init.ops = &k210_clk_ops;

        kclk->id = id;
        kclk->ksc = ksc;
        kclk->hw.init = &init;

        ret = of_clk_hw_register(np, &kclk->hw);
        if (ret) {
                pr_err("%pOFP: register clock %s failed\n",
                       np, k210_clk_cfgs[id].name);
                kclk->id = -1;
        }
}

/*
 * All muxed clocks have IN0 and PLL0 as parents.
 */
static inline void __init k210_register_mux_clk(struct device_node *np,
                                                struct k210_sysclk *ksc, int id)
{
        const struct clk_parent_data parent_data[2] = {
                { /* .index = 0 for in0 */ },
                { .hw = &ksc->plls[K210_PLL0].hw }
        };

        k210_register_clk(np, ksc, id, parent_data, 2, 0);
}

static inline void __init k210_register_in0_child(struct device_node *np,
                                                struct k210_sysclk *ksc, int id)
{
        const struct clk_parent_data parent_data = {
                /* .index = 0 for in0 */
        };

        k210_register_clk(np, ksc, id, &parent_data, 1, 0);
}

static inline void __init k210_register_pll_child(struct device_node *np,
                                                struct k210_sysclk *ksc, int id,
                                                enum k210_pll_id pllid,
                                                unsigned long flags)
{
        const struct clk_parent_data parent_data = {
                .hw = &ksc->plls[pllid].hw,
        };

        k210_register_clk(np, ksc, id, &parent_data, 1, flags);
}

static inline void __init k210_register_aclk_child(struct device_node *np,
                                                struct k210_sysclk *ksc, int id,
                                                unsigned long flags)
{
        const struct clk_parent_data parent_data = {
                .hw = &ksc->aclk,
        };

        k210_register_clk(np, ksc, id, &parent_data, 1, flags);
}

static inline void __init k210_register_clk_child(struct device_node *np,
                                                struct k210_sysclk *ksc, int id,
                                                int parent_id)
{
        const struct clk_parent_data parent_data = {
                .hw = &ksc->clks[parent_id].hw,
        };

        k210_register_clk(np, ksc, id, &parent_data, 1, 0);
}

static struct clk_hw *k210_clk_hw_onecell_get(struct of_phandle_args *clkspec,
                                              void *data)
{
        struct k210_sysclk *ksc = data;
        unsigned int idx = clkspec->args[0];

        if (idx >= K210_NUM_CLKS)
                return ERR_PTR(-EINVAL);

        return &ksc->clks[idx].hw;
}

static void __init k210_clk_init(struct device_node *np)
{
        struct device_node *sysctl_np;
        struct k210_sysclk *ksc;
        int i, ret;

        ksc = kzalloc_obj(*ksc);
        if (!ksc)
                return;

        spin_lock_init(&ksc->clk_lock);
        sysctl_np = of_get_parent(np);
        ksc->regs = of_iomap(sysctl_np, 0);
        of_node_put(sysctl_np);
        if (!ksc->regs) {
                pr_err("%pOFP: failed to map registers\n", np);
                return;
        }

        ret = k210_register_plls(np, ksc);
        if (ret)
                return;

        ret = k210_register_aclk(np, ksc);
        if (ret)
                return;

        /*
         * Critical clocks: there are no consumers of the SRAM clocks,
         * including the AI clock for the third SRAM bank. The CPU clock
         * is only referenced by the uarths serial device and so would be
         * disabled if the serial console is disabled to switch to another
         * console. Mark all these clocks as critical so that they are never
         * disabled by the core clock management.
         */
        k210_register_aclk_child(np, ksc, K210_CLK_CPU, CLK_IS_CRITICAL);
        k210_register_aclk_child(np, ksc, K210_CLK_SRAM0, CLK_IS_CRITICAL);
        k210_register_aclk_child(np, ksc, K210_CLK_SRAM1, CLK_IS_CRITICAL);
        k210_register_pll_child(np, ksc, K210_CLK_AI, K210_PLL1,
                                CLK_IS_CRITICAL);

        /* Clocks with aclk as source */
        k210_register_aclk_child(np, ksc, K210_CLK_DMA, 0);
        k210_register_aclk_child(np, ksc, K210_CLK_FFT, 0);
        k210_register_aclk_child(np, ksc, K210_CLK_ROM, 0);
        k210_register_aclk_child(np, ksc, K210_CLK_DVP, 0);
        k210_register_aclk_child(np, ksc, K210_CLK_APB0, 0);
        k210_register_aclk_child(np, ksc, K210_CLK_APB1, 0);
        k210_register_aclk_child(np, ksc, K210_CLK_APB2, 0);

        /* Clocks with PLL0 as source */
        k210_register_pll_child(np, ksc, K210_CLK_SPI0, K210_PLL0, 0);
        k210_register_pll_child(np, ksc, K210_CLK_SPI1, K210_PLL0, 0);
        k210_register_pll_child(np, ksc, K210_CLK_SPI2, K210_PLL0, 0);
        k210_register_pll_child(np, ksc, K210_CLK_I2C0, K210_PLL0, 0);
        k210_register_pll_child(np, ksc, K210_CLK_I2C1, K210_PLL0, 0);
        k210_register_pll_child(np, ksc, K210_CLK_I2C2, K210_PLL0, 0);

        /* Clocks with PLL2 as source */
        k210_register_pll_child(np, ksc, K210_CLK_I2S0, K210_PLL2, 0);
        k210_register_pll_child(np, ksc, K210_CLK_I2S1, K210_PLL2, 0);
        k210_register_pll_child(np, ksc, K210_CLK_I2S2, K210_PLL2, 0);
        k210_register_pll_child(np, ksc, K210_CLK_I2S0_M, K210_PLL2, 0);
        k210_register_pll_child(np, ksc, K210_CLK_I2S1_M, K210_PLL2, 0);
        k210_register_pll_child(np, ksc, K210_CLK_I2S2_M, K210_PLL2, 0);

        /* Clocks with IN0 as source */
        k210_register_in0_child(np, ksc, K210_CLK_WDT0);
        k210_register_in0_child(np, ksc, K210_CLK_WDT1);
        k210_register_in0_child(np, ksc, K210_CLK_RTC);

        /* Clocks with APB0 as source */
        k210_register_clk_child(np, ksc, K210_CLK_GPIO, K210_CLK_APB0);
        k210_register_clk_child(np, ksc, K210_CLK_UART1, K210_CLK_APB0);
        k210_register_clk_child(np, ksc, K210_CLK_UART2, K210_CLK_APB0);
        k210_register_clk_child(np, ksc, K210_CLK_UART3, K210_CLK_APB0);
        k210_register_clk_child(np, ksc, K210_CLK_FPIOA, K210_CLK_APB0);
        k210_register_clk_child(np, ksc, K210_CLK_SHA, K210_CLK_APB0);

        /* Clocks with APB1 as source */
        k210_register_clk_child(np, ksc, K210_CLK_AES, K210_CLK_APB1);
        k210_register_clk_child(np, ksc, K210_CLK_OTP, K210_CLK_APB1);

        /* Mux clocks with in0 or pll0 as source */
        k210_register_mux_clk(np, ksc, K210_CLK_SPI3);
        k210_register_mux_clk(np, ksc, K210_CLK_TIMER0);
        k210_register_mux_clk(np, ksc, K210_CLK_TIMER1);
        k210_register_mux_clk(np, ksc, K210_CLK_TIMER2);

        /* Check for registration errors */
        for (i = 0; i < K210_NUM_CLKS; i++) {
                if (ksc->clks[i].id != i)
                        return;
        }

        ret = of_clk_add_hw_provider(np, k210_clk_hw_onecell_get, ksc);
        if (ret) {
                pr_err("%pOFP: add clock provider failed %d\n", np, ret);
                return;
        }

        pr_info("%pOFP: CPU running at %lu MHz\n",
                np, clk_hw_get_rate(&ksc->clks[K210_CLK_CPU].hw) / 1000000);
}

CLK_OF_DECLARE(k210_clk, "canaan,k210-clk", k210_clk_init);

/*
 * Enable PLL1 to be able to use the AI SRAM.
 */
void __init k210_clk_early_init(void __iomem *regs)
{
        struct k210_pll pll1;

        /* Make sure ACLK selector is set to PLL0 */
        k210_aclk_set_selector(regs, 1);

        /* Startup PLL1 to enable the aisram bank for general memory use */
        k210_init_pll(regs, K210_PLL1, &pll1);
        k210_pll_enable_hw(regs, &pll1);
}