// SPDX-License-Identifier: GPL-2.0
/*
 * JZ4760 SoC CGU driver
 * Copyright 2018, Paul Cercueil <paul@crapouillou.net>
 */

#include <linux/bitops.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of.h>

#include <linux/clk.h>

#include <dt-bindings/clock/ingenic,jz4760-cgu.h>

#include "cgu.h"
#include "pm.h"

#define MHZ (1000 * 1000)

/*
 * CPM registers offset address definition
 */
#define CGU_REG_CPCCR		0x00
#define CGU_REG_LCR		0x04
#define CGU_REG_CPPCR0		0x10
#define CGU_REG_CLKGR0		0x20
#define CGU_REG_OPCR		0x24
#define CGU_REG_CLKGR1		0x28
#define CGU_REG_CPPCR1		0x30
#define CGU_REG_USBPCR		0x3c
#define CGU_REG_USBCDR		0x50
#define CGU_REG_I2SCDR		0x60
#define CGU_REG_LPCDR		0x64
#define CGU_REG_MSCCDR		0x68
#define CGU_REG_UHCCDR		0x6c
#define CGU_REG_SSICDR		0x74
#define CGU_REG_CIMCDR		0x7c
#define CGU_REG_GPSCDR		0x80
#define CGU_REG_PCMCDR		0x84
#define CGU_REG_GPUCDR		0x88

static const s8 pll_od_encoding[8] = {
	0x0, 0x1, -1, 0x2, -1, -1, -1, 0x3,
};

static const u8 jz4760_cgu_cpccr_div_table[] = {
	1, 2, 3, 4, 6, 8,
};

static const u8 jz4760_cgu_pll_half_div_table[] = {
	2, 1,
};

static void
jz4760_cgu_calc_m_n_od(const struct ingenic_cgu_pll_info *pll_info,
		       unsigned long rate, unsigned long parent_rate,
		       unsigned int *pm, unsigned int *pn, unsigned int *pod)
{
	unsigned int m, n, od, m_max = (1 << pll_info->m_bits) - 2;

	/* The frequency after the N divider must be between 1 and 50 MHz. */
	n = parent_rate / (1 * MHZ);

	/* The N divider must be >= 2. */
	n = clamp_val(n, 2, 1 << pll_info->n_bits);

	for (;; n >>= 1) {
		od = (unsigned int)-1;

		do {
			m = (rate / MHZ) * (1 << ++od) * n / (parent_rate / MHZ);
		} while ((m > m_max || m & 1) && (od < 4));

		if (od < 4 && m >= 4 && m <= m_max)
			break;
	}

	*pm = m;
	*pn = n;
	*pod = 1 << od;
}

static const struct ingenic_cgu_clk_info jz4760_cgu_clocks[] = {

	/* External clocks */

	[JZ4760_CLK_EXT] = { "ext", CGU_CLK_EXT },
	[JZ4760_CLK_OSC32K] = { "osc32k", CGU_CLK_EXT },

	/* PLLs */

	[JZ4760_CLK_PLL0] = {
		"pll0", CGU_CLK_PLL,
		.parents = { JZ4760_CLK_EXT },
		.pll = {
			.reg = CGU_REG_CPPCR0,
			.rate_multiplier = 1,
			.m_shift = 23,
			.m_bits = 8,
			.m_offset = 0,
			.n_shift = 18,
			.n_bits = 4,
			.n_offset = 0,
			.od_shift = 16,
			.od_bits = 2,
			.od_max = 8,
			.od_encoding = pll_od_encoding,
			.bypass_reg = CGU_REG_CPPCR0,
			.bypass_bit = 9,
			.enable_bit = 8,
			.stable_bit = 10,
			.calc_m_n_od = jz4760_cgu_calc_m_n_od,
		},
	},

	[JZ4760_CLK_PLL1] = {
		/* TODO: PLL1 can depend on PLL0 */
		"pll1", CGU_CLK_PLL,
		.parents = { JZ4760_CLK_EXT },
		.pll = {
			.reg = CGU_REG_CPPCR1,
			.rate_multiplier = 1,
			.m_shift = 23,
			.m_bits = 8,
			.m_offset = 0,
			.n_shift = 18,
			.n_bits = 4,
			.n_offset = 0,
			.od_shift = 16,
			.od_bits = 2,
			.od_max = 8,
			.od_encoding = pll_od_encoding,
			.bypass_bit = -1,
			.enable_bit = 7,
			.stable_bit = 6,
			.calc_m_n_od = jz4760_cgu_calc_m_n_od,
		},
	},

	/* Main clocks */

	[JZ4760_CLK_CCLK] = {
		"cclk", CGU_CLK_DIV,
		/*
		 * Disabling the CPU clock or any parent clocks will hang the
		 * system; mark it critical.
		 */
		.flags = CLK_IS_CRITICAL,
		.parents = { JZ4760_CLK_PLL0, },
		.div = {
			CGU_REG_CPCCR, 0, 1, 4, 22, -1, -1, 0,
			jz4760_cgu_cpccr_div_table,
		},
	},
	[JZ4760_CLK_HCLK] = {
		"hclk", CGU_CLK_DIV,
		.parents = { JZ4760_CLK_PLL0, },
		.div = {
			CGU_REG_CPCCR, 4, 1, 4, 22, -1, -1, 0,
			jz4760_cgu_cpccr_div_table,
		},
	},
	[JZ4760_CLK_SCLK] = {
		"sclk", CGU_CLK_DIV,
		.parents = { JZ4760_CLK_PLL0, },
		.div = {
			CGU_REG_CPCCR, 24, 1, 4, 22, -1, -1, 0,
			jz4760_cgu_cpccr_div_table,
		},
	},
	[JZ4760_CLK_H2CLK] = {
		"h2clk", CGU_CLK_DIV,
		.parents = { JZ4760_CLK_PLL0, },
		.div = {
			CGU_REG_CPCCR, 16, 1, 4, 22, -1, -1, 0,
			jz4760_cgu_cpccr_div_table,
		},
	},
	[JZ4760_CLK_MCLK] = {
		"mclk", CGU_CLK_DIV,
		/*
		 * Disabling MCLK or its parents will render DRAM
		 * inaccessible; mark it critical.
		 */
		.flags = CLK_IS_CRITICAL,
		.parents = { JZ4760_CLK_PLL0, },
		.div = {
			CGU_REG_CPCCR, 12, 1, 4, 22, -1, -1, 0,
			jz4760_cgu_cpccr_div_table,
		},
	},
	[JZ4760_CLK_PCLK] = {
		"pclk", CGU_CLK_DIV,
		.parents = { JZ4760_CLK_PLL0, },
		.div = {
			CGU_REG_CPCCR, 8, 1, 4, 22, -1, -1, 0,
			jz4760_cgu_cpccr_div_table,
		},
	},

	/* Divided clocks */

	[JZ4760_CLK_PLL0_HALF] = {
		"pll0_half", CGU_CLK_DIV,
		.parents = { JZ4760_CLK_PLL0 },
		.div = {
			CGU_REG_CPCCR, 21, 1, 1, 22, -1, -1, 0,
			jz4760_cgu_pll_half_div_table,
		},
	},

	/* Those divided clocks can connect to PLL0 or PLL1 */

	[JZ4760_CLK_UHC] = {
		"uhc", CGU_CLK_DIV | CGU_CLK_GATE | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_PLL0_HALF, JZ4760_CLK_PLL1, },
		.mux = { CGU_REG_UHCCDR, 31, 1 },
		.div = { CGU_REG_UHCCDR, 0, 1, 4, -1, -1, -1 },
		.gate = { CGU_REG_CLKGR0, 24 },
	},
	[JZ4760_CLK_GPU] = {
		"gpu", CGU_CLK_DIV | CGU_CLK_GATE | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_PLL0_HALF, JZ4760_CLK_PLL1, },
		.mux = { CGU_REG_GPUCDR, 31, 1 },
		.div = { CGU_REG_GPUCDR, 0, 1, 3, -1, -1, -1 },
		.gate = { CGU_REG_CLKGR1, 9 },
	},
	[JZ4760_CLK_LPCLK_DIV] = {
		"lpclk_div", CGU_CLK_DIV | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_PLL0_HALF, JZ4760_CLK_PLL1, },
		.mux = { CGU_REG_LPCDR, 29, 1 },
		.div = { CGU_REG_LPCDR, 0, 1, 11, -1, -1, -1 },
	},
	[JZ4760_CLK_TVE] = {
		"tve", CGU_CLK_GATE | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_LPCLK_DIV, JZ4760_CLK_EXT, },
		.mux = { CGU_REG_LPCDR, 31, 1 },
		.gate = { CGU_REG_CLKGR0, 27 },
	},
	[JZ4760_CLK_LPCLK] = {
		"lpclk", CGU_CLK_GATE | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_LPCLK_DIV, JZ4760_CLK_TVE, },
		.mux = { CGU_REG_LPCDR, 30, 1 },
		.gate = { CGU_REG_CLKGR0, 28 },
	},
	[JZ4760_CLK_GPS] = {
		"gps", CGU_CLK_DIV | CGU_CLK_GATE | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_PLL0_HALF, JZ4760_CLK_PLL1, },
		.mux = { CGU_REG_GPSCDR, 31, 1 },
		.div = { CGU_REG_GPSCDR, 0, 1, 4, -1, -1, -1 },
		.gate = { CGU_REG_CLKGR0, 22 },
	},

	/* Those divided clocks can connect to EXT, PLL0 or PLL1 */

	[JZ4760_CLK_PCM] = {
		"pcm", CGU_CLK_DIV | CGU_CLK_GATE | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_EXT, -1,
			JZ4760_CLK_PLL0_HALF, JZ4760_CLK_PLL1 },
		.mux = { CGU_REG_PCMCDR, 30, 2 },
		.div = { CGU_REG_PCMCDR, 0, 1, 9, -1, -1, -1, BIT(0) },
		.gate = { CGU_REG_CLKGR1, 8 },
	},
	[JZ4760_CLK_I2S] = {
		"i2s", CGU_CLK_DIV | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_EXT, -1,
			JZ4760_CLK_PLL0_HALF, JZ4760_CLK_PLL1 },
		.mux = { CGU_REG_I2SCDR, 30, 2 },
		.div = { CGU_REG_I2SCDR, 0, 1, 9, -1, -1, -1, BIT(0) },
	},
	[JZ4760_CLK_OTG] = {
		"usb", CGU_CLK_DIV | CGU_CLK_GATE | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_EXT, -1,
			JZ4760_CLK_PLL0_HALF, JZ4760_CLK_PLL1 },
		.mux = { CGU_REG_USBCDR, 30, 2 },
		.div = { CGU_REG_USBCDR, 0, 1, 8, -1, -1, -1 },
		.gate = { CGU_REG_CLKGR0, 2 },
	},

	/* Those divided clocks can connect to EXT or PLL0 */
	[JZ4760_CLK_MMC_MUX] = {
		"mmc_mux", CGU_CLK_MUX | CGU_CLK_DIV,
		.parents = { JZ4760_CLK_EXT, JZ4760_CLK_PLL0_HALF, },
		.mux = { CGU_REG_MSCCDR, 31, 1 },
		.div = { CGU_REG_MSCCDR, 0, 1, 6, -1, -1, -1, BIT(0) },
	},
	[JZ4760_CLK_SSI_MUX] = {
		"ssi_mux", CGU_CLK_DIV | CGU_CLK_MUX,
		.parents = { JZ4760_CLK_EXT, JZ4760_CLK_PLL0_HALF, },
		.mux = { CGU_REG_SSICDR, 31, 1 },
		.div = { CGU_REG_SSICDR, 0, 1, 6, -1, -1, -1, BIT(0) },
	},

	/* These divided clock can connect to PLL0 only */
	[JZ4760_CLK_CIM] = {
		"cim", CGU_CLK_DIV | CGU_CLK_GATE,
		.parents = { JZ4760_CLK_PLL0_HALF },
		.div = { CGU_REG_CIMCDR, 0, 1, 8, -1, -1, -1 },
		.gate = { CGU_REG_CLKGR0, 26 },
	},

	/* Gate-only clocks */

	[JZ4760_CLK_SSI0] = {
		"ssi0", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_SSI_MUX, },
		.gate = { CGU_REG_CLKGR0, 4 },
	},
	[JZ4760_CLK_SSI1] = {
		"ssi1", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_SSI_MUX, },
		.gate = { CGU_REG_CLKGR0, 19 },
	},
	[JZ4760_CLK_SSI2] = {
		"ssi2", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_SSI_MUX, },
		.gate = { CGU_REG_CLKGR0, 20 },
	},
	[JZ4760_CLK_DMA] = {
		"dma", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_H2CLK, },
		.gate = { CGU_REG_CLKGR0, 21 },
	},
	[JZ4760_CLK_MDMA] = {
		"mdma", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_HCLK, },
		.gate = { CGU_REG_CLKGR0, 25 },
	},
	[JZ4760_CLK_BDMA] = {
		"bdma", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_HCLK, },
		.gate = { CGU_REG_CLKGR1, 0 },
	},
	[JZ4760_CLK_I2C0] = {
		"i2c0", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_EXT, },
		.gate = { CGU_REG_CLKGR0, 5 },
	},
	[JZ4760_CLK_I2C1] = {
		"i2c1", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_EXT, },
		.gate = { CGU_REG_CLKGR0, 6 },
	},
	[JZ4760_CLK_UART0] = {
		"uart0", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_EXT, },
		.gate = { CGU_REG_CLKGR0, 15 },
	},
	[JZ4760_CLK_UART1] = {
		"uart1", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_EXT, },
		.gate = { CGU_REG_CLKGR0, 16 },
	},
	[JZ4760_CLK_UART2] = {
		"uart2", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_EXT, },
		.gate = { CGU_REG_CLKGR0, 17 },
	},
	[JZ4760_CLK_UART3] = {
		"uart3", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_EXT, },
		.gate = { CGU_REG_CLKGR0, 18 },
	},
	[JZ4760_CLK_IPU] = {
		"ipu", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_HCLK, },
		.gate = { CGU_REG_CLKGR0, 29 },
	},
	[JZ4760_CLK_ADC] = {
		"adc", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_EXT, },
		.gate = { CGU_REG_CLKGR0, 14 },
	},
	[JZ4760_CLK_AIC] = {
		"aic", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_EXT, },
		.gate = { CGU_REG_CLKGR0, 8 },
	},
	[JZ4760_CLK_VPU] = {
		"vpu", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_HCLK, },
		.gate = { CGU_REG_LCR, 30, false, 150 },
	},
	[JZ4760_CLK_MMC0] = {
		"mmc0", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_MMC_MUX, },
		.gate = { CGU_REG_CLKGR0, 3 },
	},
	[JZ4760_CLK_MMC1] = {
		"mmc1", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_MMC_MUX, },
		.gate = { CGU_REG_CLKGR0, 11 },
	},
	[JZ4760_CLK_MMC2] = {
		"mmc2", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_MMC_MUX, },
		.gate = { CGU_REG_CLKGR0, 12 },
	},
	[JZ4760_CLK_UHC_PHY] = {
		"uhc_phy", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_UHC, },
		.gate = { CGU_REG_OPCR, 5 },
	},
	[JZ4760_CLK_OTG_PHY] = {
		"usb_phy", CGU_CLK_GATE,
		.parents = { JZ4760_CLK_OTG },
		.gate = { CGU_REG_OPCR, 7, true, 50 },
	},

	/* Custom clocks */
	[JZ4760_CLK_EXT512] = {
		"ext/512", CGU_CLK_FIXDIV,
		.parents = { JZ4760_CLK_EXT },
		.fixdiv = { 512 },
	},
	[JZ4760_CLK_RTC] = {
		"rtc", CGU_CLK_MUX,
		.parents = { JZ4760_CLK_EXT512, JZ4760_CLK_OSC32K, },
		.mux = { CGU_REG_OPCR, 2, 1},
	},
};

static void __init jz4760_cgu_init(struct device_node *np)
{
	struct ingenic_cgu *cgu;
	int retval;

	cgu = ingenic_cgu_new(jz4760_cgu_clocks,
			      ARRAY_SIZE(jz4760_cgu_clocks), np);
	if (!cgu) {
		pr_err("%s: failed to initialise CGU\n", __func__);
		return;
	}

	retval = ingenic_cgu_register_clocks(cgu);
	if (retval)
		pr_err("%s: failed to register CGU Clocks\n", __func__);

	ingenic_cgu_register_syscore_ops(cgu);
}

/* We only probe via devicetree, no need for a platform driver */
CLK_OF_DECLARE_DRIVER(jz4760_cgu, "ingenic,jz4760-cgu", jz4760_cgu_init);

/* JZ4760B has some small differences, but we don't implement them. */
CLK_OF_DECLARE_DRIVER(jz4760b_cgu, "ingenic,jz4760b-cgu", jz4760_cgu_init);