/*
 * Copyright (c) 2015 MediaTek Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/phy/phy.h>

#define MIPITX_DSI_CON		0x00
#define RG_DSI_LDOCORE_EN		BIT(0)
#define RG_DSI_CKG_LDOOUT_EN		BIT(1)
#define RG_DSI_BCLK_SEL			(3 << 2)
#define RG_DSI_LD_IDX_SEL		(7 << 4)
#define RG_DSI_PHYCLK_SEL		(2 << 8)
#define RG_DSI_DSICLK_FREQ_SEL		BIT(10)
#define RG_DSI_LPTX_CLMP_EN		BIT(11)

#define MIPITX_DSI_CLOCK_LANE	0x04
#define MIPITX_DSI_DATA_LANE0	0x08
#define MIPITX_DSI_DATA_LANE1	0x0c
#define MIPITX_DSI_DATA_LANE2	0x10
#define MIPITX_DSI_DATA_LANE3	0x14
#define RG_DSI_LNTx_LDOOUT_EN		BIT(0)
#define RG_DSI_LNTx_CKLANE_EN		BIT(1)
#define RG_DSI_LNTx_LPTX_IPLUS1		BIT(2)
#define RG_DSI_LNTx_LPTX_IPLUS2		BIT(3)
#define RG_DSI_LNTx_LPTX_IMINUS		BIT(4)
#define RG_DSI_LNTx_LPCD_IPLUS		BIT(5)
#define RG_DSI_LNTx_LPCD_IMINUS		BIT(6)
#define RG_DSI_LNTx_RT_CODE		(0xf << 8)

#define MIPITX_DSI_TOP_CON	0x40
#define RG_DSI_LNT_INTR_EN		BIT(0)
#define RG_DSI_LNT_HS_BIAS_EN		BIT(1)
#define RG_DSI_LNT_IMP_CAL_EN		BIT(2)
#define RG_DSI_LNT_TESTMODE_EN		BIT(3)
#define RG_DSI_LNT_IMP_CAL_CODE		(0xf << 4)
#define RG_DSI_LNT_AIO_SEL		(7 << 8)
#define RG_DSI_PAD_TIE_LOW_EN		BIT(11)
#define RG_DSI_DEBUG_INPUT_EN		BIT(12)
#define RG_DSI_PRESERVE			(7 << 13)

#define MIPITX_DSI_BG_CON	0x44
#define RG_DSI_BG_CORE_EN		BIT(0)
#define RG_DSI_BG_CKEN			BIT(1)
#define RG_DSI_BG_DIV			(0x3 << 2)
#define RG_DSI_BG_FAST_CHARGE		BIT(4)
#define RG_DSI_VOUT_MSK			(0x3ffff << 5)
#define RG_DSI_V12_SEL			(7 << 5)
#define RG_DSI_V10_SEL			(7 << 8)
#define RG_DSI_V072_SEL			(7 << 11)
#define RG_DSI_V04_SEL			(7 << 14)
#define RG_DSI_V032_SEL			(7 << 17)
#define RG_DSI_V02_SEL			(7 << 20)
#define RG_DSI_BG_R1_TRIM		(0xf << 24)
#define RG_DSI_BG_R2_TRIM		(0xf << 28)

#define MIPITX_DSI_PLL_CON0	0x50
#define RG_DSI_MPPLL_PLL_EN		BIT(0)
#define RG_DSI_MPPLL_DIV_MSK		(0x1ff << 1)
#define RG_DSI_MPPLL_PREDIV		(3 << 1)
#define RG_DSI_MPPLL_TXDIV0		(3 << 3)
#define RG_DSI_MPPLL_TXDIV1		(3 << 5)
#define RG_DSI_MPPLL_POSDIV		(7 << 7)
#define RG_DSI_MPPLL_MONVC_EN		BIT(10)
#define RG_DSI_MPPLL_MONREF_EN		BIT(11)
#define RG_DSI_MPPLL_VOD_EN		BIT(12)

#define MIPITX_DSI_PLL_CON1	0x54
#define RG_DSI_MPPLL_SDM_FRA_EN		BIT(0)
#define RG_DSI_MPPLL_SDM_SSC_PH_INIT	BIT(1)
#define RG_DSI_MPPLL_SDM_SSC_EN		BIT(2)
#define RG_DSI_MPPLL_SDM_SSC_PRD	(0xffff << 16)

#define MIPITX_DSI_PLL_CON2	0x58

#define MIPITX_DSI_PLL_PWR	0x68
#define RG_DSI_MPPLL_SDM_PWR_ON		BIT(0)
#define RG_DSI_MPPLL_SDM_ISO_EN		BIT(1)
#define RG_DSI_MPPLL_SDM_PWR_ACK	BIT(8)

#define MIPITX_DSI_SW_CTRL	0x80
#define SW_CTRL_EN			BIT(0)

#define MIPITX_DSI_SW_CTRL_CON0	0x84
#define SW_LNTC_LPTX_PRE_OE		BIT(0)
#define SW_LNTC_LPTX_OE			BIT(1)
#define SW_LNTC_LPTX_P			BIT(2)
#define SW_LNTC_LPTX_N			BIT(3)
#define SW_LNTC_HSTX_PRE_OE		BIT(4)
#define SW_LNTC_HSTX_OE			BIT(5)
#define SW_LNTC_HSTX_ZEROCLK		BIT(6)
#define SW_LNT0_LPTX_PRE_OE		BIT(7)
#define SW_LNT0_LPTX_OE			BIT(8)
#define SW_LNT0_LPTX_P			BIT(9)
#define SW_LNT0_LPTX_N			BIT(10)
#define SW_LNT0_HSTX_PRE_OE		BIT(11)
#define SW_LNT0_HSTX_OE			BIT(12)
#define SW_LNT0_LPRX_EN			BIT(13)
#define SW_LNT1_LPTX_PRE_OE		BIT(14)
#define SW_LNT1_LPTX_OE			BIT(15)
#define SW_LNT1_LPTX_P			BIT(16)
#define SW_LNT1_LPTX_N			BIT(17)
#define SW_LNT1_HSTX_PRE_OE		BIT(18)
#define SW_LNT1_HSTX_OE			BIT(19)
#define SW_LNT2_LPTX_PRE_OE		BIT(20)
#define SW_LNT2_LPTX_OE			BIT(21)
#define SW_LNT2_LPTX_P			BIT(22)
#define SW_LNT2_LPTX_N			BIT(23)
#define SW_LNT2_HSTX_PRE_OE		BIT(24)
#define SW_LNT2_HSTX_OE			BIT(25)

struct mtk_mipi_tx {
	struct device *dev;
	void __iomem *regs;
	unsigned int data_rate;
	struct clk_hw pll_hw;
	struct clk *pll;
};

static inline struct mtk_mipi_tx *mtk_mipi_tx_from_clk_hw(struct clk_hw *hw)
{
	return container_of(hw, struct mtk_mipi_tx, pll_hw);
}

static void mtk_mipi_tx_clear_bits(struct mtk_mipi_tx *mipi_tx, u32 offset,
				   u32 bits)
{
	u32 temp = readl(mipi_tx->regs + offset);

	writel(temp & ~bits, mipi_tx->regs + offset);
}

static void mtk_mipi_tx_set_bits(struct mtk_mipi_tx *mipi_tx, u32 offset,
				 u32 bits)
{
	u32 temp = readl(mipi_tx->regs + offset);

	writel(temp | bits, mipi_tx->regs + offset);
}

static void mtk_mipi_tx_update_bits(struct mtk_mipi_tx *mipi_tx, u32 offset,
				    u32 mask, u32 data)
{
	u32 temp = readl(mipi_tx->regs + offset);

	writel((temp & ~mask) | (data & mask), mipi_tx->regs + offset);
}

static int mtk_mipi_tx_pll_prepare(struct clk_hw *hw)
{
	struct mtk_mipi_tx *mipi_tx = mtk_mipi_tx_from_clk_hw(hw);
	unsigned int txdiv, txdiv0, txdiv1;
	u64 pcw;

	dev_dbg(mipi_tx->dev, "prepare: %u Hz\n", mipi_tx->data_rate);

	if (mipi_tx->data_rate >= 500000000) {
		txdiv = 1;
		txdiv0 = 0;
		txdiv1 = 0;
	} else if (mipi_tx->data_rate >= 250000000) {
		txdiv = 2;
		txdiv0 = 1;
		txdiv1 = 0;
	} else if (mipi_tx->data_rate >= 125000000) {
		txdiv = 4;
		txdiv0 = 2;
		txdiv1 = 0;
	} else if (mipi_tx->data_rate > 62000000) {
		txdiv = 8;
		txdiv0 = 2;
		txdiv1 = 1;
	} else if (mipi_tx->data_rate >= 50000000) {
		txdiv = 16;
		txdiv0 = 2;
		txdiv1 = 2;
	} else {
		return -EINVAL;
	}

	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_BG_CON,
				RG_DSI_VOUT_MSK |
				RG_DSI_BG_CKEN | RG_DSI_BG_CORE_EN,
				(4 << 20) | (4 << 17) | (4 << 14) |
				(4 << 11) | (4 << 8) | (4 << 5) |
				RG_DSI_BG_CKEN | RG_DSI_BG_CORE_EN);

	usleep_range(30, 100);

	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_TOP_CON,
				RG_DSI_LNT_IMP_CAL_CODE | RG_DSI_LNT_HS_BIAS_EN,
				(8 << 4) | RG_DSI_LNT_HS_BIAS_EN);

	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_DSI_CON,
			     RG_DSI_CKG_LDOOUT_EN | RG_DSI_LDOCORE_EN);

	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_PLL_PWR,
				RG_DSI_MPPLL_SDM_PWR_ON |
				RG_DSI_MPPLL_SDM_ISO_EN,
				RG_DSI_MPPLL_SDM_PWR_ON);

	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_PLL_CON0,
			       RG_DSI_MPPLL_PLL_EN);

	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_PLL_CON0,
				RG_DSI_MPPLL_TXDIV0 | RG_DSI_MPPLL_TXDIV1 |
				RG_DSI_MPPLL_PREDIV,
				(txdiv0 << 3) | (txdiv1 << 5));

	/*
	 * PLL PCW config
	 * PCW bit 24~30 = integer part of pcw
	 * PCW bit 0~23 = fractional part of pcw
	 * pcw = data_Rate*4*txdiv/(Ref_clk*2);
	 * Post DIV =4, so need data_Rate*4
	 * Ref_clk is 26MHz
	 */
	pcw = div_u64(((u64)mipi_tx->data_rate * 2 * txdiv) << 24,
		      26000000);
	writel(pcw, mipi_tx->regs + MIPITX_DSI_PLL_CON2);

	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_DSI_PLL_CON1,
			     RG_DSI_MPPLL_SDM_FRA_EN);

	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_DSI_PLL_CON0, RG_DSI_MPPLL_PLL_EN);

	usleep_range(20, 100);

	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_PLL_CON1,
			       RG_DSI_MPPLL_SDM_SSC_EN);

	return 0;
}

static void mtk_mipi_tx_pll_unprepare(struct clk_hw *hw)
{
	struct mtk_mipi_tx *mipi_tx = mtk_mipi_tx_from_clk_hw(hw);

	dev_dbg(mipi_tx->dev, "unprepare\n");

	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_PLL_CON0,
			       RG_DSI_MPPLL_PLL_EN);

	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_PLL_PWR,
				RG_DSI_MPPLL_SDM_ISO_EN |
				RG_DSI_MPPLL_SDM_PWR_ON,
				RG_DSI_MPPLL_SDM_ISO_EN);

	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_TOP_CON,
			       RG_DSI_LNT_HS_BIAS_EN);

	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_CON,
			       RG_DSI_CKG_LDOOUT_EN | RG_DSI_LDOCORE_EN);

	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_BG_CON,
			       RG_DSI_BG_CKEN | RG_DSI_BG_CORE_EN);

	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_PLL_CON0,
			       RG_DSI_MPPLL_DIV_MSK);
}

static long mtk_mipi_tx_pll_round_rate(struct clk_hw *hw, unsigned long rate,
				       unsigned long *prate)
{
	return clamp_val(rate, 50000000, 1250000000);
}

static int mtk_mipi_tx_pll_set_rate(struct clk_hw *hw, unsigned long rate,
				    unsigned long parent_rate)
{
	struct mtk_mipi_tx *mipi_tx = mtk_mipi_tx_from_clk_hw(hw);

	dev_dbg(mipi_tx->dev, "set rate: %lu Hz\n", rate);

	mipi_tx->data_rate = rate;

	return 0;
}

static unsigned long mtk_mipi_tx_pll_recalc_rate(struct clk_hw *hw,
						 unsigned long parent_rate)
{
	struct mtk_mipi_tx *mipi_tx = mtk_mipi_tx_from_clk_hw(hw);

	return mipi_tx->data_rate;
}

static const struct clk_ops mtk_mipi_tx_pll_ops = {
	.prepare = mtk_mipi_tx_pll_prepare,
	.unprepare = mtk_mipi_tx_pll_unprepare,
	.round_rate = mtk_mipi_tx_pll_round_rate,
	.set_rate = mtk_mipi_tx_pll_set_rate,
	.recalc_rate = mtk_mipi_tx_pll_recalc_rate,
};

static int mtk_mipi_tx_power_on_signal(struct phy *phy)
{
	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
	unsigned int reg;

	for (reg = MIPITX_DSI_CLOCK_LANE;
	     reg <= MIPITX_DSI_DATA_LANE3; reg += 4)
		mtk_mipi_tx_set_bits(mipi_tx, reg, RG_DSI_LNTx_LDOOUT_EN);

	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_TOP_CON,
			       RG_DSI_PAD_TIE_LOW_EN);

	return 0;
}

static int mtk_mipi_tx_power_on(struct phy *phy)
{
	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
	int ret;

	/* Power up core and enable PLL */
	ret = clk_prepare_enable(mipi_tx->pll);
	if (ret < 0)
		return ret;

	/* Enable DSI Lane LDO outputs, disable pad tie low */
	mtk_mipi_tx_power_on_signal(phy);

	return 0;
}

static void mtk_mipi_tx_power_off_signal(struct phy *phy)
{
	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
	unsigned int reg;

	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_DSI_TOP_CON,
			     RG_DSI_PAD_TIE_LOW_EN);

	for (reg = MIPITX_DSI_CLOCK_LANE;
	     reg <= MIPITX_DSI_DATA_LANE3; reg += 4)
		mtk_mipi_tx_clear_bits(mipi_tx, reg, RG_DSI_LNTx_LDOOUT_EN);
}

static int mtk_mipi_tx_power_off(struct phy *phy)
{
	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);

	/* Enable pad tie low, disable DSI Lane LDO outputs */
	mtk_mipi_tx_power_off_signal(phy);

	/* Disable PLL and power down core */
	clk_disable_unprepare(mipi_tx->pll);

	return 0;
}

static const struct phy_ops mtk_mipi_tx_ops = {
	.power_on = mtk_mipi_tx_power_on,
	.power_off = mtk_mipi_tx_power_off,
	.owner = THIS_MODULE,
};

static int mtk_mipi_tx_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct mtk_mipi_tx *mipi_tx;
	struct resource *mem;
	struct clk *ref_clk;
	const char *ref_clk_name;
	struct clk_init_data clk_init = {
		.ops = &mtk_mipi_tx_pll_ops,
		.num_parents = 1,
		.parent_names = (const char * const *)&ref_clk_name,
		.flags = CLK_SET_RATE_GATE,
	};
	struct phy *phy;
	struct phy_provider *phy_provider;
	int ret;

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

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	mipi_tx->regs = devm_ioremap_resource(dev, mem);
	if (IS_ERR(mipi_tx->regs)) {
		ret = PTR_ERR(mipi_tx->regs);
		dev_err(dev, "Failed to get memory resource: %d\n", ret);
		return ret;
	}

	ref_clk = devm_clk_get(dev, NULL);
	if (IS_ERR(ref_clk)) {
		ret = PTR_ERR(ref_clk);
		dev_err(dev, "Failed to get reference clock: %d\n", ret);
		return ret;
	}
	ref_clk_name = __clk_get_name(ref_clk);

	ret = of_property_read_string(dev->of_node, "clock-output-names",
				      &clk_init.name);
	if (ret < 0) {
		dev_err(dev, "Failed to read clock-output-names: %d\n", ret);
		return ret;
	}

	mipi_tx->pll_hw.init = &clk_init;
	mipi_tx->pll = devm_clk_register(dev, &mipi_tx->pll_hw);
	if (IS_ERR(mipi_tx->pll)) {
		ret = PTR_ERR(mipi_tx->pll);
		dev_err(dev, "Failed to register PLL: %d\n", ret);
		return ret;
	}

	phy = devm_phy_create(dev, NULL, &mtk_mipi_tx_ops);
	if (IS_ERR(phy)) {
		ret = PTR_ERR(phy);
		dev_err(dev, "Failed to create MIPI D-PHY: %d\n", ret);
		return ret;
	}
	phy_set_drvdata(phy, mipi_tx);

	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
	if (IS_ERR(phy)) {
		ret = PTR_ERR(phy_provider);
		return ret;
	}

	mipi_tx->dev = dev;

	return of_clk_add_provider(dev->of_node, of_clk_src_simple_get,
				   mipi_tx->pll);
}

static int mtk_mipi_tx_remove(struct platform_device *pdev)
{
	of_clk_del_provider(pdev->dev.of_node);
	return 0;
}

static const struct of_device_id mtk_mipi_tx_match[] = {
	{ .compatible = "mediatek,mt8173-mipi-tx", },
	{},
};

struct platform_driver mtk_mipi_tx_driver = {
	.probe = mtk_mipi_tx_probe,
	.remove = mtk_mipi_tx_remove,
	.driver = {
		.name = "mediatek-mipi-tx",
		.of_match_table = mtk_mipi_tx_match,
	},
};