// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/*
 * Copyright (C) Sunplus Technology Co., Ltd.
 *       All rights reserved.
 */
#include <linux/module.h>
#include <linux/clk-provider.h>
#include <linux/of.h>
#include <linux/bitfield.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/platform_device.h>

#include <dt-bindings/clock/sunplus,sp7021-clkc.h>

/* speical div_width values for PLLTV/PLLA */
#define DIV_TV		33
#define DIV_A		34

/* PLLTV parameters */
enum {
	SEL_FRA,
	SDM_MOD,
	PH_SEL,
	NFRA,
	DIVR,
	DIVN,
	DIVM,
	P_MAX
};

#define MASK_SEL_FRA	GENMASK(1, 1)
#define MASK_SDM_MOD	GENMASK(2, 2)
#define MASK_PH_SEL	GENMASK(4, 4)
#define MASK_NFRA	GENMASK(12, 6)
#define MASK_DIVR	GENMASK(8, 7)
#define MASK_DIVN	GENMASK(7, 0)
#define MASK_DIVM	GENMASK(14, 8)

/* HIWORD_MASK FIELD_PREP */
#define HWM_FIELD_PREP(mask, value)		\
({						\
	u64 _m = mask;				\
	(_m << 16) | FIELD_PREP(_m, value);	\
})

struct sp_pll {
	struct clk_hw hw;
	void __iomem *reg;
	spinlock_t lock;	/* lock for reg */
	int div_shift;
	int div_width;
	int pd_bit;		/* power down bit idx */
	int bp_bit;		/* bypass bit idx */
	unsigned long brate;	/* base rate, TODO: replace brate with muldiv */
	u32 p[P_MAX];		/* for hold PLLTV/PLLA parameters */
};

#define to_sp_pll(_hw)	container_of(_hw, struct sp_pll, hw)

struct sp_clk_gate_info {
	u16	reg;		/* reg_index_shift */
	u16	ext_parent;	/* parent is extclk */
};

static const struct sp_clk_gate_info sp_clk_gates[] = {
	{ 0x02 },
	{ 0x05 },
	{ 0x06 },
	{ 0x07 },
	{ 0x09 },
	{ 0x0b, 1 },
	{ 0x0f, 1 },
	{ 0x14 },
	{ 0x15 },
	{ 0x16 },
	{ 0x17 },
	{ 0x18, 1 },
	{ 0x19, 1 },
	{ 0x1a, 1 },
	{ 0x1b, 1 },
	{ 0x1c, 1 },
	{ 0x1d, 1 },
	{ 0x1e },
	{ 0x1f, 1 },
	{ 0x20 },
	{ 0x21 },
	{ 0x22 },
	{ 0x23 },
	{ 0x24 },
	{ 0x25 },
	{ 0x26 },
	{ 0x2a },
	{ 0x2b },
	{ 0x2d },
	{ 0x2e },
	{ 0x30 },
	{ 0x31 },
	{ 0x32 },
	{ 0x33 },
	{ 0x3d },
	{ 0x3e },
	{ 0x3f },
	{ 0x42 },
	{ 0x44 },
	{ 0x4b },
	{ 0x4c },
	{ 0x4d },
	{ 0x4e },
	{ 0x4f },
	{ 0x50 },
	{ 0x55 },
	{ 0x60 },
	{ 0x61 },
	{ 0x6a },
	{ 0x73 },
	{ 0x86 },
	{ 0x8a },
	{ 0x8b },
	{ 0x8d },
	{ 0x8e },
	{ 0x8f },
	{ 0x90 },
	{ 0x92 },
	{ 0x93 },
	{ 0x95 },
	{ 0x96 },
	{ 0x97 },
	{ 0x98 },
	{ 0x99 },
};

#define _M		1000000UL
#define F_27M		(27 * _M)

/*********************************** PLL_TV **********************************/

/* TODO: set proper FVCO range */
#define FVCO_MIN	(100 * _M)
#define FVCO_MAX	(200 * _M)

#define F_MIN		(FVCO_MIN / 8)
#define F_MAX		(FVCO_MAX)

static long plltv_integer_div(struct sp_pll *clk, unsigned long freq)
{
	/* valid m values: 27M must be divisible by m */
	static const u32 m_table[] = {
		1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 25, 27, 30, 32
	};
	u32 m, n, r;
	unsigned long fvco, nf;
	long ret;

	freq = clamp(freq, F_MIN, F_MAX);

	/* DIVR 0~3 */
	for (r = 0; r <= 3; r++) {
		fvco = freq << r;
		if (fvco <= FVCO_MAX)
			break;
	}

	/* DIVM */
	for (m = 0; m < ARRAY_SIZE(m_table); m++) {
		nf = fvco * m_table[m];
		n = nf / F_27M;
		if ((n * F_27M) == nf)
			break;
	}
	if (m >= ARRAY_SIZE(m_table)) {
		ret = -EINVAL;
		goto err_not_found;
	}

	/* save parameters */
	clk->p[SEL_FRA] = 0;
	clk->p[DIVR]    = r;
	clk->p[DIVN]    = n;
	clk->p[DIVM]    = m_table[m];

	return freq;

err_not_found:
	pr_err("%s: %s freq:%lu not found a valid setting\n",
	       __func__, clk_hw_get_name(&clk->hw), freq);

	return ret;
}

/* parameters for PLLTV fractional divider */
static const u32 pt[][5] = {
	/* conventional fractional */
	{
		1,			/* factor */
		5,			/* 5 * p0 (nint) */
		1,			/* 1 * p0 */
		F_27M,			/* F_27M / p0 */
		1,			/* p0 / p2 */
	},
	/* phase rotation */
	{
		10,			/* factor */
		54,			/* 5.4 * p0 (nint) */
		2,			/* 0.2 * p0 */
		F_27M / 10,		/* F_27M / p0 */
		5,			/* p0 / p2 */
	},
};

static const u32 sdm_mod_vals[] = { 91, 55 };

static long plltv_fractional_div(struct sp_pll *clk, unsigned long freq)
{
	u32 m, r;
	u32 nint, nfra;
	u32 df_quotient_min = 210000000;
	u32 df_remainder_min = 0;
	unsigned long fvco, nf, f, fout = 0;
	int sdm, ph;

	freq = clamp(freq, F_MIN, F_MAX);

	/* DIVR 0~3 */
	for (r = 0; r <= 3; r++) {
		fvco = freq << r;
		if (fvco <= FVCO_MAX)
			break;
	}
	f = F_27M >> r;

	/* PH_SEL */
	for (ph = ARRAY_SIZE(pt) - 1; ph >= 0; ph--) {
		const u32 *pp = pt[ph];

		/* SDM_MOD */
		for (sdm = 0; sdm < ARRAY_SIZE(sdm_mod_vals); sdm++) {
			u32 mod = sdm_mod_vals[sdm];

			/* DIVM 1~32 */
			for (m = 1; m <= 32; m++) {
				u32 df; /* diff freq */
				u32 df_quotient, df_remainder;

				nf = fvco * m;
				nint = nf / pp[3];

				if (nint < pp[1])
					continue;
				if (nint > pp[1])
					break;

				nfra = (((nf % pp[3]) * mod * pp[4]) + (F_27M / 2)) / F_27M;
				if (nfra) {
					u32 df0 = f * (nint + pp[2]) / pp[0];
					u32 df1 = f * (mod - nfra) / mod / pp[4];

					df = df0 - df1;
				} else {
					df = f * (nint) / pp[0];
				}

				df_quotient  = df / m;
				df_remainder = ((df % m) * 1000) / m;

				if (freq > df_quotient) {
					df_quotient  = freq - df_quotient - 1;
					df_remainder = 1000 - df_remainder;
				} else {
					df_quotient = df_quotient - freq;
				}

				if (df_quotient_min > df_quotient ||
				    (df_quotient_min == df_quotient &&
				    df_remainder_min > df_remainder)) {
					/* found a closer freq, save parameters */
					clk->p[SEL_FRA] = 1;
					clk->p[SDM_MOD] = sdm;
					clk->p[PH_SEL]  = ph;
					clk->p[NFRA]    = nfra;
					clk->p[DIVR]    = r;
					clk->p[DIVM]    = m;

					fout = df / m;
					df_quotient_min = df_quotient;
					df_remainder_min = df_remainder;
				}
			}
		}
	}

	if (!fout) {
		pr_err("%s: %s freq:%lu not found a valid setting\n",
		       __func__, clk_hw_get_name(&clk->hw), freq);
		return -EINVAL;
	}

	return fout;
}

static long plltv_div(struct sp_pll *clk, unsigned long freq)
{
	if (freq % 100)
		return plltv_fractional_div(clk, freq);

	return plltv_integer_div(clk, freq);
}

static int plltv_set_rate(struct sp_pll *clk)
{
	unsigned long flags;
	u32 r0, r1, r2;

	r0  = BIT(clk->bp_bit + 16);
	r0 |= HWM_FIELD_PREP(MASK_SEL_FRA, clk->p[SEL_FRA]);
	r0 |= HWM_FIELD_PREP(MASK_SDM_MOD, clk->p[SDM_MOD]);
	r0 |= HWM_FIELD_PREP(MASK_PH_SEL, clk->p[PH_SEL]);
	r0 |= HWM_FIELD_PREP(MASK_NFRA, clk->p[NFRA]);

	r1  = HWM_FIELD_PREP(MASK_DIVR, clk->p[DIVR]);

	r2  = HWM_FIELD_PREP(MASK_DIVN, clk->p[DIVN] - 1);
	r2 |= HWM_FIELD_PREP(MASK_DIVM, clk->p[DIVM] - 1);

	spin_lock_irqsave(&clk->lock, flags);
	writel(r0, clk->reg);
	writel(r1, clk->reg + 4);
	writel(r2, clk->reg + 8);
	spin_unlock_irqrestore(&clk->lock, flags);

	return 0;
}

/*********************************** PLL_A ***********************************/

/* from Q628_PLLs_REG_setting.xlsx */
static const struct {
	u32 rate;
	u32 regs[5];
} pa[] = {
	{
		.rate = 135475200,
		.regs = {
			0x4801,
			0x02df,
			0x248f,
			0x0211,
			0x33e9
		}
	},
	{
		.rate = 147456000,
		.regs = {
			0x4801,
			0x1adf,
			0x2490,
			0x0349,
			0x33e9
		}
	},
	{
		.rate = 196608000,
		.regs = {
			0x4801,
			0x42ef,
			0x2495,
			0x01c6,
			0x33e9
		}
	},
};

static int plla_set_rate(struct sp_pll *clk)
{
	const u32 *pp = pa[clk->p[0]].regs;
	unsigned long flags;
	int i;

	spin_lock_irqsave(&clk->lock, flags);
	for (i = 0; i < ARRAY_SIZE(pa->regs); i++)
		writel(0xffff0000 | pp[i], clk->reg + (i * 4));
	spin_unlock_irqrestore(&clk->lock, flags);

	return 0;
}

static long plla_round_rate(struct sp_pll *clk, unsigned long rate)
{
	int i = ARRAY_SIZE(pa);

	while (--i) {
		if (rate >= pa[i].rate)
			break;
	}
	clk->p[0] = i;

	return pa[i].rate;
}

/********************************** SP_PLL ***********************************/

static long sp_pll_calc_div(struct sp_pll *clk, unsigned long rate)
{
	u32 fbdiv;
	u32 max = 1 << clk->div_width;

	fbdiv = DIV_ROUND_CLOSEST(rate, clk->brate);
	if (fbdiv > max)
		fbdiv = max;

	return fbdiv;
}

static long sp_pll_round_rate(struct clk_hw *hw, unsigned long rate,
			      unsigned long *prate)
{
	struct sp_pll *clk = to_sp_pll(hw);
	long ret;

	if (rate == *prate) {
		ret = *prate; /* bypass */
	} else if (clk->div_width == DIV_A) {
		ret = plla_round_rate(clk, rate);
	} else if (clk->div_width == DIV_TV) {
		ret = plltv_div(clk, rate);
		if (ret < 0)
			ret = *prate;
	} else {
		ret = sp_pll_calc_div(clk, rate) * clk->brate;
	}

	return ret;
}

static unsigned long sp_pll_recalc_rate(struct clk_hw *hw,
					unsigned long prate)
{
	struct sp_pll *clk = to_sp_pll(hw);
	u32 reg = readl(clk->reg);
	unsigned long ret;

	if (reg & BIT(clk->bp_bit)) {
		ret = prate; /* bypass */
	} else if (clk->div_width == DIV_A) {
		ret = pa[clk->p[0]].rate;
	} else if (clk->div_width == DIV_TV) {
		u32 m, r, reg2;

		r = FIELD_GET(MASK_DIVR, readl(clk->reg + 4));
		reg2 = readl(clk->reg + 8);
		m = FIELD_GET(MASK_DIVM, reg2) + 1;

		if (reg & MASK_SEL_FRA) {
			/* fractional divider */
			u32 sdm  = FIELD_GET(MASK_SDM_MOD, reg);
			u32 ph   = FIELD_GET(MASK_PH_SEL, reg);
			u32 nfra = FIELD_GET(MASK_NFRA, reg);
			const u32 *pp = pt[ph];
			unsigned long r0, r1;

			ret = prate >> r;
			r0  = ret * (pp[1] + pp[2]) / pp[0];
			r1  = ret * (sdm_mod_vals[sdm] - nfra) / sdm_mod_vals[sdm] / pp[4];
			ret = (r0 - r1) / m;
		} else {
			/* integer divider */
			u32 n = FIELD_GET(MASK_DIVN, reg2) + 1;

			ret = (prate / m * n) >> r;
		}
	} else {
		u32 fbdiv = ((reg >> clk->div_shift) & ((1 << clk->div_width) - 1)) + 1;

		ret = clk->brate * fbdiv;
	}

	return ret;
}

static int sp_pll_set_rate(struct clk_hw *hw, unsigned long rate,
			   unsigned long prate)
{
	struct sp_pll *clk = to_sp_pll(hw);
	unsigned long flags;
	u32 reg;

	reg = BIT(clk->bp_bit + 16); /* HIWORD_MASK */

	if (rate == prate) {
		reg |= BIT(clk->bp_bit); /* bypass */
	} else if (clk->div_width == DIV_A) {
		return plla_set_rate(clk);
	} else if (clk->div_width == DIV_TV) {
		return plltv_set_rate(clk);
	} else if (clk->div_width) {
		u32 fbdiv = sp_pll_calc_div(clk, rate);
		u32 mask = GENMASK(clk->div_shift + clk->div_width - 1, clk->div_shift);

		reg |= mask << 16;
		reg |= ((fbdiv - 1) << clk->div_shift) & mask;
	}

	spin_lock_irqsave(&clk->lock, flags);
	writel(reg, clk->reg);
	spin_unlock_irqrestore(&clk->lock, flags);

	return 0;
}

static int sp_pll_enable(struct clk_hw *hw)
{
	struct sp_pll *clk = to_sp_pll(hw);

	writel(BIT(clk->pd_bit + 16) | BIT(clk->pd_bit), clk->reg);

	return 0;
}

static void sp_pll_disable(struct clk_hw *hw)
{
	struct sp_pll *clk = to_sp_pll(hw);

	writel(BIT(clk->pd_bit + 16), clk->reg);
}

static int sp_pll_is_enabled(struct clk_hw *hw)
{
	struct sp_pll *clk = to_sp_pll(hw);

	return readl(clk->reg) & BIT(clk->pd_bit);
}

static const struct clk_ops sp_pll_ops = {
	.enable = sp_pll_enable,
	.disable = sp_pll_disable,
	.is_enabled = sp_pll_is_enabled,
	.round_rate = sp_pll_round_rate,
	.recalc_rate = sp_pll_recalc_rate,
	.set_rate = sp_pll_set_rate
};

static const struct clk_ops sp_pll_sub_ops = {
	.enable = sp_pll_enable,
	.disable = sp_pll_disable,
	.is_enabled = sp_pll_is_enabled,
	.recalc_rate = sp_pll_recalc_rate,
};

static struct clk_hw *sp_pll_register(struct device *dev, const char *name,
				      const struct clk_parent_data *parent_data,
				      void __iomem *reg, int pd_bit, int bp_bit,
				      unsigned long brate, int shift, int width,
				      unsigned long flags)
{
	struct sp_pll *pll;
	struct clk_hw *hw;
	struct clk_init_data initd = {
		.name = name,
		.parent_data = parent_data,
		.ops = (bp_bit >= 0) ? &sp_pll_ops : &sp_pll_sub_ops,
		.num_parents = 1,
		.flags = flags,
	};
	int ret;

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

	pll->hw.init = &initd;
	pll->reg = reg;
	pll->pd_bit = pd_bit;
	pll->bp_bit = bp_bit;
	pll->brate = brate;
	pll->div_shift = shift;
	pll->div_width = width;
	spin_lock_init(&pll->lock);

	hw = &pll->hw;
	ret = devm_clk_hw_register(dev, hw);
	if (ret)
		return ERR_PTR(ret);

	return hw;
}

#define PLLA_CTL	(pll_base + 0x1c)
#define PLLE_CTL	(pll_base + 0x30)
#define PLLF_CTL	(pll_base + 0x34)
#define PLLTV_CTL	(pll_base + 0x38)

static int sp7021_clk_probe(struct platform_device *pdev)
{
	static const u32 sp_clken[] = {
		0x67ef, 0x03ff, 0xff03, 0xfff0, 0x0004, /* G0.1~5  */
		0x0000, 0x8000, 0xffff, 0x0040, 0x0000, /* G0.6~10 */
	};
	static struct clk_parent_data pd_ext, pd_sys, pd_e;
	struct device *dev = &pdev->dev;
	void __iomem *clk_base, *pll_base, *sys_base;
	struct clk_hw_onecell_data *clk_data;
	struct clk_hw **hws;
	int i;

	clk_base = devm_platform_ioremap_resource(pdev, 0);
	if (!clk_base)
		return -ENXIO;
	pll_base = devm_platform_ioremap_resource(pdev, 1);
	if (!pll_base)
		return -ENXIO;
	sys_base = devm_platform_ioremap_resource(pdev, 2);
	if (!sys_base)
		return -ENXIO;

	/* enable default clks */
	for (i = 0; i < ARRAY_SIZE(sp_clken); i++)
		writel((sp_clken[i] << 16) | sp_clken[i], clk_base + i * 4);

	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, CLK_MAX),
				GFP_KERNEL);
	if (!clk_data)
		return -ENOMEM;

	hws = clk_data->hws;
	pd_ext.index = 0;

	/* PLLs */
	hws[PLL_A] = sp_pll_register(dev, "plla", &pd_ext, PLLA_CTL,
				     11, 12, 27000000, 0, DIV_A, 0);
	if (IS_ERR(hws[PLL_A]))
		return PTR_ERR(hws[PLL_A]);

	hws[PLL_E] = sp_pll_register(dev, "plle", &pd_ext, PLLE_CTL,
				     6, 2, 50000000, 0, 0, 0);
	if (IS_ERR(hws[PLL_E]))
		return PTR_ERR(hws[PLL_E]);
	pd_e.hw = hws[PLL_E];
	hws[PLL_E_2P5] = sp_pll_register(dev, "plle_2p5", &pd_e, PLLE_CTL,
					 13, -1, 2500000, 0, 0, 0);
	if (IS_ERR(hws[PLL_E_2P5]))
		return PTR_ERR(hws[PLL_E_2P5]);
	hws[PLL_E_25] = sp_pll_register(dev, "plle_25", &pd_e, PLLE_CTL,
					12, -1, 25000000, 0, 0, 0);
	if (IS_ERR(hws[PLL_E_25]))
		return PTR_ERR(hws[PLL_E_25]);
	hws[PLL_E_112P5] = sp_pll_register(dev, "plle_112p5", &pd_e, PLLE_CTL,
					   11, -1, 112500000, 0, 0, 0);
	if (IS_ERR(hws[PLL_E_112P5]))
		return PTR_ERR(hws[PLL_E_112P5]);

	hws[PLL_F] = sp_pll_register(dev, "pllf", &pd_ext, PLLF_CTL,
				     0, 10, 13500000, 1, 4, 0);
	if (IS_ERR(hws[PLL_F]))
		return PTR_ERR(hws[PLL_F]);

	hws[PLL_TV] = sp_pll_register(dev, "plltv", &pd_ext, PLLTV_CTL,
				      0, 15, 27000000, 0, DIV_TV, 0);
	if (IS_ERR(hws[PLL_TV]))
		return PTR_ERR(hws[PLL_TV]);
	hws[PLL_TV_A] = devm_clk_hw_register_divider(dev, "plltv_a", "plltv", 0,
						     PLLTV_CTL + 4, 5, 1,
						     CLK_DIVIDER_POWER_OF_TWO,
						     &to_sp_pll(hws[PLL_TV])->lock);
	if (IS_ERR(hws[PLL_TV_A]))
		return PTR_ERR(hws[PLL_TV_A]);

	/* system clock, should not be disabled */
	hws[PLL_SYS] = sp_pll_register(dev, "pllsys", &pd_ext, sys_base,
				       10, 9, 13500000, 0, 4, CLK_IS_CRITICAL);
	if (IS_ERR(hws[PLL_SYS]))
		return PTR_ERR(hws[PLL_SYS]);
	pd_sys.hw = hws[PLL_SYS];

	/* gates */
	for (i = 0; i < ARRAY_SIZE(sp_clk_gates); i++) {
		char name[10];
		u32 j = sp_clk_gates[i].reg;
		struct clk_parent_data *pd = sp_clk_gates[i].ext_parent ? &pd_ext : &pd_sys;

		sprintf(name, "%02d_0x%02x", i, j);
		hws[i] = devm_clk_hw_register_gate_parent_data(dev, name, pd, 0,
							       clk_base + (j >> 4) * 4,
							       j & 0x0f,
							       CLK_GATE_HIWORD_MASK,
							       NULL);
		if (IS_ERR(hws[i]))
			return PTR_ERR(hws[i]);
	}

	clk_data->num = CLK_MAX;

	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
}

static const struct of_device_id sp7021_clk_dt_ids[] = {
	{ .compatible = "sunplus,sp7021-clkc" },
	{ }
};
MODULE_DEVICE_TABLE(of, sp7021_clk_dt_ids);

static struct platform_driver sp7021_clk_driver = {
	.probe  = sp7021_clk_probe,
	.driver = {
		.name = "sp7021-clk",
		.of_match_table = sp7021_clk_dt_ids,
	},
};
module_platform_driver(sp7021_clk_driver);

MODULE_AUTHOR("Sunplus Technology");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Clock driver for Sunplus SP7021 SoC");