exynos_drm_dsi.c

/*
 * Samsung SoC MIPI DSI Master driver.
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd
 *
 * Contacts: Tomasz Figa <t.figa@samsung.com>
 *
 * 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.
*/

#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_panel.h>

#include <linux/clk.h>
#include <linux/gpio/consumer.h>
#include <linux/irq.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/phy/phy.h>
#include <linux/regulator/consumer.h>
#include <linux/component.h>

#include <video/mipi_display.h>
#include <video/videomode.h>

#include "exynos_drm_crtc.h"
#include "exynos_drm_drv.h"

/* returns true iff both arguments logically differs */
#define NEQV(a, b) (!(a) ^ !(b))

#define DSIM_STATUS_REG		0x0	/* Status register */
#define DSIM_SWRST_REG		0x4	/* Software reset register */
#define DSIM_CLKCTRL_REG	0x8	/* Clock control register */
#define DSIM_TIMEOUT_REG	0xc	/* Time out register */
#define DSIM_CONFIG_REG		0x10	/* Configuration register */
#define DSIM_ESCMODE_REG	0x14	/* Escape mode register */

/* Main display image resolution register */
#define DSIM_MDRESOL_REG	0x18
#define DSIM_MVPORCH_REG	0x1c	/* Main display Vporch register */
#define DSIM_MHPORCH_REG	0x20	/* Main display Hporch register */
#define DSIM_MSYNC_REG		0x24	/* Main display sync area register */

/* Sub display image resolution register */
#define DSIM_SDRESOL_REG	0x28
#define DSIM_INTSRC_REG		0x2c	/* Interrupt source register */
#define DSIM_INTMSK_REG		0x30	/* Interrupt mask register */
#define DSIM_PKTHDR_REG		0x34	/* Packet Header FIFO register */
#define DSIM_PAYLOAD_REG	0x38	/* Payload FIFO register */
#define DSIM_RXFIFO_REG		0x3c	/* Read FIFO register */
#define DSIM_FIFOTHLD_REG	0x40	/* FIFO threshold level register */
#define DSIM_FIFOCTRL_REG	0x44	/* FIFO status and control register */

/* FIFO memory AC characteristic register */
#define DSIM_PLLCTRL_REG	0x4c	/* PLL control register */
#define DSIM_PHYACCHR_REG	0x54	/* D-PHY AC characteristic register */
#define DSIM_PHYACCHR1_REG	0x58	/* D-PHY AC characteristic register1 */
#define DSIM_PHYCTRL_REG	0x5c
#define DSIM_PHYTIMING_REG	0x64
#define DSIM_PHYTIMING1_REG	0x68
#define DSIM_PHYTIMING2_REG	0x6c

/* DSIM_STATUS */
#define DSIM_STOP_STATE_DAT(x)		(((x) & 0xf) << 0)
#define DSIM_STOP_STATE_CLK		(1 << 8)
#define DSIM_TX_READY_HS_CLK		(1 << 10)
#define DSIM_PLL_STABLE			(1 << 31)

/* DSIM_SWRST */
#define DSIM_FUNCRST			(1 << 16)
#define DSIM_SWRST			(1 << 0)

/* DSIM_TIMEOUT */
#define DSIM_LPDR_TIMEOUT(x)		((x) << 0)
#define DSIM_BTA_TIMEOUT(x)		((x) << 16)

/* DSIM_CLKCTRL */
#define DSIM_ESC_PRESCALER(x)		(((x) & 0xffff) << 0)
#define DSIM_ESC_PRESCALER_MASK		(0xffff << 0)
#define DSIM_LANE_ESC_CLK_EN_CLK	(1 << 19)
#define DSIM_LANE_ESC_CLK_EN_DATA(x)	(((x) & 0xf) << 20)
#define DSIM_LANE_ESC_CLK_EN_DATA_MASK	(0xf << 20)
#define DSIM_BYTE_CLKEN			(1 << 24)
#define DSIM_BYTE_CLK_SRC(x)		(((x) & 0x3) << 25)
#define DSIM_BYTE_CLK_SRC_MASK		(0x3 << 25)
#define DSIM_PLL_BYPASS			(1 << 27)
#define DSIM_ESC_CLKEN			(1 << 28)
#define DSIM_TX_REQUEST_HSCLK		(1 << 31)

/* DSIM_CONFIG */
#define DSIM_LANE_EN_CLK		(1 << 0)
#define DSIM_LANE_EN(x)			(((x) & 0xf) << 1)
#define DSIM_NUM_OF_DATA_LANE(x)	(((x) & 0x3) << 5)
#define DSIM_SUB_PIX_FORMAT(x)		(((x) & 0x7) << 8)
#define DSIM_MAIN_PIX_FORMAT_MASK	(0x7 << 12)
#define DSIM_MAIN_PIX_FORMAT_RGB888	(0x7 << 12)
#define DSIM_MAIN_PIX_FORMAT_RGB666	(0x6 << 12)
#define DSIM_MAIN_PIX_FORMAT_RGB666_P	(0x5 << 12)
#define DSIM_MAIN_PIX_FORMAT_RGB565	(0x4 << 12)
#define DSIM_SUB_VC			(((x) & 0x3) << 16)
#define DSIM_MAIN_VC			(((x) & 0x3) << 18)
#define DSIM_HSA_MODE			(1 << 20)
#define DSIM_HBP_MODE			(1 << 21)
#define DSIM_HFP_MODE			(1 << 22)
#define DSIM_HSE_MODE			(1 << 23)
#define DSIM_AUTO_MODE			(1 << 24)
#define DSIM_VIDEO_MODE			(1 << 25)
#define DSIM_BURST_MODE			(1 << 26)
#define DSIM_SYNC_INFORM		(1 << 27)
#define DSIM_EOT_DISABLE		(1 << 28)
#define DSIM_MFLUSH_VS			(1 << 29)

/* DSIM_ESCMODE */
#define DSIM_TX_TRIGGER_RST		(1 << 4)
#define DSIM_TX_LPDT_LP			(1 << 6)
#define DSIM_CMD_LPDT_LP		(1 << 7)
#define DSIM_FORCE_BTA			(1 << 16)
#define DSIM_FORCE_STOP_STATE		(1 << 20)
#define DSIM_STOP_STATE_CNT(x)		(((x) & 0x7ff) << 21)
#define DSIM_STOP_STATE_CNT_MASK	(0x7ff << 21)

/* DSIM_MDRESOL */
#define DSIM_MAIN_STAND_BY		(1 << 31)
#define DSIM_MAIN_VRESOL(x)		(((x) & 0x7ff) << 16)
#define DSIM_MAIN_HRESOL(x)		(((x) & 0X7ff) << 0)

/* DSIM_MVPORCH */
#define DSIM_CMD_ALLOW(x)		((x) << 28)
#define DSIM_STABLE_VFP(x)		((x) << 16)
#define DSIM_MAIN_VBP(x)		((x) << 0)
#define DSIM_CMD_ALLOW_MASK		(0xf << 28)
#define DSIM_STABLE_VFP_MASK		(0x7ff << 16)
#define DSIM_MAIN_VBP_MASK		(0x7ff << 0)

/* DSIM_MHPORCH */
#define DSIM_MAIN_HFP(x)		((x) << 16)
#define DSIM_MAIN_HBP(x)		((x) << 0)
#define DSIM_MAIN_HFP_MASK		((0xffff) << 16)
#define DSIM_MAIN_HBP_MASK		((0xffff) << 0)

/* DSIM_MSYNC */
#define DSIM_MAIN_VSA(x)		((x) << 22)
#define DSIM_MAIN_HSA(x)		((x) << 0)
#define DSIM_MAIN_VSA_MASK		((0x3ff) << 22)
#define DSIM_MAIN_HSA_MASK		((0xffff) << 0)

/* DSIM_SDRESOL */
#define DSIM_SUB_STANDY(x)		((x) << 31)
#define DSIM_SUB_VRESOL(x)		((x) << 16)
#define DSIM_SUB_HRESOL(x)		((x) << 0)
#define DSIM_SUB_STANDY_MASK		((0x1) << 31)
#define DSIM_SUB_VRESOL_MASK		((0x7ff) << 16)
#define DSIM_SUB_HRESOL_MASK		((0x7ff) << 0)

/* DSIM_INTSRC */
#define DSIM_INT_PLL_STABLE		(1 << 31)
#define DSIM_INT_SW_RST_RELEASE		(1 << 30)
#define DSIM_INT_SFR_FIFO_EMPTY		(1 << 29)
#define DSIM_INT_BTA			(1 << 25)
#define DSIM_INT_FRAME_DONE		(1 << 24)
#define DSIM_INT_RX_TIMEOUT		(1 << 21)
#define DSIM_INT_BTA_TIMEOUT		(1 << 20)
#define DSIM_INT_RX_DONE		(1 << 18)
#define DSIM_INT_RX_TE			(1 << 17)
#define DSIM_INT_RX_ACK			(1 << 16)
#define DSIM_INT_RX_ECC_ERR		(1 << 15)
#define DSIM_INT_RX_CRC_ERR		(1 << 14)

/* DSIM_FIFOCTRL */
#define DSIM_RX_DATA_FULL		(1 << 25)
#define DSIM_RX_DATA_EMPTY		(1 << 24)
#define DSIM_SFR_HEADER_FULL		(1 << 23)
#define DSIM_SFR_HEADER_EMPTY		(1 << 22)
#define DSIM_SFR_PAYLOAD_FULL		(1 << 21)
#define DSIM_SFR_PAYLOAD_EMPTY		(1 << 20)
#define DSIM_I80_HEADER_FULL		(1 << 19)
#define DSIM_I80_HEADER_EMPTY		(1 << 18)
#define DSIM_I80_PAYLOAD_FULL		(1 << 17)
#define DSIM_I80_PAYLOAD_EMPTY		(1 << 16)
#define DSIM_SD_HEADER_FULL		(1 << 15)
#define DSIM_SD_HEADER_EMPTY		(1 << 14)
#define DSIM_SD_PAYLOAD_FULL		(1 << 13)
#define DSIM_SD_PAYLOAD_EMPTY		(1 << 12)
#define DSIM_MD_HEADER_FULL		(1 << 11)
#define DSIM_MD_HEADER_EMPTY		(1 << 10)
#define DSIM_MD_PAYLOAD_FULL		(1 << 9)
#define DSIM_MD_PAYLOAD_EMPTY		(1 << 8)
#define DSIM_RX_FIFO			(1 << 4)
#define DSIM_SFR_FIFO			(1 << 3)
#define DSIM_I80_FIFO			(1 << 2)
#define DSIM_SD_FIFO			(1 << 1)
#define DSIM_MD_FIFO			(1 << 0)

/* DSIM_PHYACCHR */
#define DSIM_AFC_EN			(1 << 14)
#define DSIM_AFC_CTL(x)			(((x) & 0x7) << 5)

/* DSIM_PLLCTRL */
#define DSIM_FREQ_BAND(x)		((x) << 24)
#define DSIM_PLL_EN			(1 << 23)
#define DSIM_PLL_P(x)			((x) << 13)
#define DSIM_PLL_M(x)			((x) << 4)
#define DSIM_PLL_S(x)			((x) << 1)

/* DSIM_PHYCTRL */
#define DSIM_PHYCTRL_ULPS_EXIT(x)	(((x) & 0x1ff) << 0)

/* DSIM_PHYTIMING */
#define DSIM_PHYTIMING_LPX(x)		((x) << 8)
#define DSIM_PHYTIMING_HS_EXIT(x)	((x) << 0)

/* DSIM_PHYTIMING1 */
#define DSIM_PHYTIMING1_CLK_PREPARE(x)	((x) << 24)
#define DSIM_PHYTIMING1_CLK_ZERO(x)	((x) << 16)
#define DSIM_PHYTIMING1_CLK_POST(x)	((x) << 8)
#define DSIM_PHYTIMING1_CLK_TRAIL(x)	((x) << 0)

/* DSIM_PHYTIMING2 */
#define DSIM_PHYTIMING2_HS_PREPARE(x)	((x) << 16)
#define DSIM_PHYTIMING2_HS_ZERO(x)	((x) << 8)
#define DSIM_PHYTIMING2_HS_TRAIL(x)	((x) << 0)

#define DSI_MAX_BUS_WIDTH		4
#define DSI_NUM_VIRTUAL_CHANNELS	4
#define DSI_TX_FIFO_SIZE		2048
#define DSI_RX_FIFO_SIZE		256
#define DSI_XFER_TIMEOUT_MS		100
#define DSI_RX_FIFO_EMPTY		0x30800002

enum exynos_dsi_transfer_type {
	EXYNOS_DSI_TX,
	EXYNOS_DSI_RX,
};

struct exynos_dsi_transfer {
	struct list_head list;
	struct completion completed;
	int result;
	u8 data_id;
	u8 data[2];
	u16 flags;

	const u8 *tx_payload;
	u16 tx_len;
	u16 tx_done;

	u8 *rx_payload;
	u16 rx_len;
	u16 rx_done;
};

#define DSIM_STATE_ENABLED		BIT(0)
#define DSIM_STATE_INITIALIZED		BIT(1)
#define DSIM_STATE_CMD_LPM		BIT(2)

struct exynos_dsi_driver_data {
	unsigned int plltmr_reg;

	unsigned int has_freqband:1;
};

struct exynos_dsi {
	struct mipi_dsi_host dsi_host;
	struct drm_connector connector;
	struct drm_encoder *encoder;
	struct device_node *panel_node;
	struct drm_panel *panel;
	struct device *dev;

	void __iomem *reg_base;
	struct phy *phy;
	struct clk *pll_clk;
	struct clk *bus_clk;
	struct regulator_bulk_data supplies[2];
	int irq;
	int te_gpio;

	u32 pll_clk_rate;
	u32 burst_clk_rate;
	u32 esc_clk_rate;
	u32 lanes;
	u32 mode_flags;
	u32 format;
	struct videomode vm;

	int state;
	struct drm_property *brightness;
	struct completion completed;

	spinlock_t transfer_lock; /* protects transfer_list */
	struct list_head transfer_list;

	struct exynos_dsi_driver_data *driver_data;
};

#define host_to_dsi(host) container_of(host, struct exynos_dsi, dsi_host)
#define connector_to_dsi(c) container_of(c, struct exynos_dsi, connector)

static struct exynos_dsi_driver_data exynos4_dsi_driver_data = {
	.plltmr_reg = 0x50,
	.has_freqband = 1,
};

static struct exynos_dsi_driver_data exynos5_dsi_driver_data = {
	.plltmr_reg = 0x58,
};

static struct of_device_id exynos_dsi_of_match[] = {
	{ .compatible = "samsung,exynos4210-mipi-dsi",
	  .data = &exynos4_dsi_driver_data },
	{ .compatible = "samsung,exynos5410-mipi-dsi",
	  .data = &exynos5_dsi_driver_data },
	{ }
};

static inline struct exynos_dsi_driver_data *exynos_dsi_get_driver_data(
						struct platform_device *pdev)
{
	const struct of_device_id *of_id =
			of_match_device(exynos_dsi_of_match, &pdev->dev);

	return (struct exynos_dsi_driver_data *)of_id->data;
}

static void exynos_dsi_wait_for_reset(struct exynos_dsi *dsi)
{
	if (wait_for_completion_timeout(&dsi->completed, msecs_to_jiffies(300)))
		return;

	dev_err(dsi->dev, "timeout waiting for reset\n");
}

static void exynos_dsi_reset(struct exynos_dsi *dsi)
{
	reinit_completion(&dsi->completed);
	writel(DSIM_SWRST, dsi->reg_base + DSIM_SWRST_REG);
}

#ifndef MHZ
#define MHZ	(1000*1000)
#endif

static unsigned long exynos_dsi_pll_find_pms(struct exynos_dsi *dsi,
		unsigned long fin, unsigned long fout, u8 *p, u16 *m, u8 *s)
{
	unsigned long best_freq = 0;
	u32 min_delta = 0xffffffff;
	u8 p_min, p_max;
	u8 _p, uninitialized_var(best_p);
	u16 _m, uninitialized_var(best_m);
	u8 _s, uninitialized_var(best_s);

	p_min = DIV_ROUND_UP(fin, (12 * MHZ));
	p_max = fin / (6 * MHZ);

	for (_p = p_min; _p <= p_max; ++_p) {
		for (_s = 0; _s <= 5; ++_s) {
			u64 tmp;
			u32 delta;

			tmp = (u64)fout * (_p << _s);
			do_div(tmp, fin);
			_m = tmp;
			if (_m < 41 || _m > 125)
				continue;

			tmp = (u64)_m * fin;
			do_div(tmp, _p);
			if (tmp < 500 * MHZ || tmp > 1000 * MHZ)
				continue;

			tmp = (u64)_m * fin;
			do_div(tmp, _p << _s);

			delta = abs(fout - tmp);
			if (delta < min_delta) {
				best_p = _p;
				best_m = _m;
				best_s = _s;
				min_delta = delta;
				best_freq = tmp;
			}
		}
	}

	if (best_freq) {
		*p = best_p;
		*m = best_m;
		*s = best_s;
	}

	return best_freq;
}

static unsigned long exynos_dsi_set_pll(struct exynos_dsi *dsi,
					unsigned long freq)
{
	struct exynos_dsi_driver_data *driver_data = dsi->driver_data;
	unsigned long fin, fout;
	int timeout;
	u8 p, s;
	u16 m;
	u32 reg;

	clk_set_rate(dsi->pll_clk, dsi->pll_clk_rate);

	fin = clk_get_rate(dsi->pll_clk);
	if (!fin) {
		dev_err(dsi->dev, "failed to get PLL clock frequency\n");
		return 0;
	}

	dev_dbg(dsi->dev, "PLL input frequency: %lu\n", fin);

	fout = exynos_dsi_pll_find_pms(dsi, fin, freq, &p, &m, &s);
	if (!fout) {
		dev_err(dsi->dev,
			"failed to find PLL PMS for requested frequency\n");
		return -EFAULT;
	}
	dev_dbg(dsi->dev, "PLL freq %lu, (p %d, m %d, s %d)\n", fout, p, m, s);

	writel(500, dsi->reg_base + driver_data->plltmr_reg);

	reg = DSIM_PLL_EN | DSIM_PLL_P(p) | DSIM_PLL_M(m) | DSIM_PLL_S(s);

	if (driver_data->has_freqband) {
		static const unsigned long freq_bands[] = {
			100 * MHZ, 120 * MHZ, 160 * MHZ, 200 * MHZ,
			270 * MHZ, 320 * MHZ, 390 * MHZ, 450 * MHZ,
			510 * MHZ, 560 * MHZ, 640 * MHZ, 690 * MHZ,
			770 * MHZ, 870 * MHZ, 950 * MHZ,
		};
		int band;

		for (band = 0; band < ARRAY_SIZE(freq_bands); ++band)
			if (fout < freq_bands[band])
				break;

		dev_dbg(dsi->dev, "band %d\n", band);

		reg |= DSIM_FREQ_BAND(band);
	}

	writel(reg, dsi->reg_base + DSIM_PLLCTRL_REG);

	timeout = 1000;
	do {
		if (timeout-- == 0) {
			dev_err(dsi->dev, "PLL failed to stabilize\n");
			return -EFAULT;
		}
		reg = readl(dsi->reg_base + DSIM_STATUS_REG);
	} while ((reg & DSIM_PLL_STABLE) == 0);

	return fout;
}

static int exynos_dsi_enable_clock(struct exynos_dsi *dsi)
{
	unsigned long hs_clk, byte_clk, esc_clk;
	unsigned long esc_div;
	u32 reg;

	hs_clk = exynos_dsi_set_pll(dsi, dsi->burst_clk_rate);
	if (!hs_clk) {
		dev_err(dsi->dev, "failed to configure DSI PLL\n");
		return -EFAULT;
	}

	byte_clk = hs_clk / 8;
	esc_div = DIV_ROUND_UP(byte_clk, dsi->esc_clk_rate);
	esc_clk = byte_clk / esc_div;

	if (esc_clk > 20 * MHZ) {
		++esc_div;
		esc_clk = byte_clk / esc_div;
	}

	dev_dbg(dsi->dev, "hs_clk = %lu, byte_clk = %lu, esc_clk = %lu\n",
		hs_clk, byte_clk, esc_clk);

	reg = readl(dsi->reg_base + DSIM_CLKCTRL_REG);
	reg &= ~(DSIM_ESC_PRESCALER_MASK | DSIM_LANE_ESC_CLK_EN_CLK
			| DSIM_LANE_ESC_CLK_EN_DATA_MASK | DSIM_PLL_BYPASS
			| DSIM_BYTE_CLK_SRC_MASK);
	reg |= DSIM_ESC_CLKEN | DSIM_BYTE_CLKEN
			| DSIM_ESC_PRESCALER(esc_div)
			| DSIM_LANE_ESC_CLK_EN_CLK
			| DSIM_LANE_ESC_CLK_EN_DATA(BIT(dsi->lanes) - 1)
			| DSIM_BYTE_CLK_SRC(0)
			| DSIM_TX_REQUEST_HSCLK;
	writel(reg, dsi->reg_base + DSIM_CLKCTRL_REG);

	return 0;
}

static void exynos_dsi_set_phy_ctrl(struct exynos_dsi *dsi)
{
	struct exynos_dsi_driver_data *driver_data = dsi->driver_data;
	u32 reg;

	if (driver_data->has_freqband)
		return;

	/* B D-PHY: D-PHY Master & Slave Analog Block control */
	reg = DSIM_PHYCTRL_ULPS_EXIT(0x0af);
	writel(reg, dsi->reg_base + DSIM_PHYCTRL_REG);

	/*
	 * T LPX: Transmitted length of any Low-Power state period
	 * T HS-EXIT: Time that the transmitter drives LP-11 following a HS
	 *	burst
	 */
	reg = DSIM_PHYTIMING_LPX(0x06) | DSIM_PHYTIMING_HS_EXIT(0x0b);
	writel(reg, dsi->reg_base + DSIM_PHYTIMING_REG);

	/*
	 * T CLK-PREPARE: Time that the transmitter drives the Clock Lane LP-00
	 *	Line state immediately before the HS-0 Line state starting the
	 *	HS transmission
	 * T CLK-ZERO: Time that the transmitter drives the HS-0 state prior to
	 *	transmitting the Clock.
	 * T CLK_POST: Time that the transmitter continues to send HS clock
	 *	after the last associated Data Lane has transitioned to LP Mode
	 *	Interval is defined as the period from the end of T HS-TRAIL to
	 *	the beginning of T CLK-TRAIL
	 * T CLK-TRAIL: Time that the transmitter drives the HS-0 state after
	 *	the last payload clock bit of a HS transmission burst
	 */
	reg = DSIM_PHYTIMING1_CLK_PREPARE(0x07) |
			DSIM_PHYTIMING1_CLK_ZERO(0x27) |
			DSIM_PHYTIMING1_CLK_POST(0x0d) |
			DSIM_PHYTIMING1_CLK_TRAIL(0x08);
	writel(reg, dsi->reg_base + DSIM_PHYTIMING1_REG);

	/*
	 * T HS-PREPARE: Time that the transmitter drives the Data Lane LP-00
	 *	Line state immediately before the HS-0 Line state starting the
	 *	HS transmission
	 * T HS-ZERO: Time that the transmitter drives the HS-0 state prior to
	 *	transmitting the Sync sequence.
	 * T HS-TRAIL: Time that the transmitter drives the flipped differential
	 *	state after last payload data bit of a HS transmission burst
	 */
	reg = DSIM_PHYTIMING2_HS_PREPARE(0x09) | DSIM_PHYTIMING2_HS_ZERO(0x0d) |
			DSIM_PHYTIMING2_HS_TRAIL(0x0b);
	writel(reg, dsi->reg_base + DSIM_PHYTIMING2_REG);
}

static void exynos_dsi_disable_clock(struct exynos_dsi *dsi)
{
	u32 reg;

	reg = readl(dsi->reg_base + DSIM_CLKCTRL_REG);
	reg &= ~(DSIM_LANE_ESC_CLK_EN_CLK | DSIM_LANE_ESC_CLK_EN_DATA_MASK
			| DSIM_ESC_CLKEN | DSIM_BYTE_CLKEN);
	writel(reg, dsi->reg_base + DSIM_CLKCTRL_REG);

	reg = readl(dsi->reg_base + DSIM_PLLCTRL_REG);
	reg &= ~DSIM_PLL_EN;
	writel(reg, dsi->reg_base + DSIM_PLLCTRL_REG);
}

static int exynos_dsi_init_link(struct exynos_dsi *dsi)
{
	int timeout;
	u32 reg;
	u32 lanes_mask;

	/* Initialize FIFO pointers */
	reg = readl(dsi->reg_base + DSIM_FIFOCTRL_REG);
	reg &= ~0x1f;
	writel(reg, dsi->reg_base + DSIM_FIFOCTRL_REG);

	usleep_range(9000, 11000);

	reg |= 0x1f;
	writel(reg, dsi->reg_base + DSIM_FIFOCTRL_REG);

	usleep_range(9000, 11000);

	/* DSI configuration */
	reg = 0;

	/*
	 * The first bit of mode_flags specifies display configuration.
	 * If this bit is set[= MIPI_DSI_MODE_VIDEO], dsi will support video
	 * mode, otherwise it will support command mode.
	 */
	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
		reg |= DSIM_VIDEO_MODE;

		/*
		 * The user manual describes that following bits are ignored in
		 * command mode.
		 */
		if (!(dsi->mode_flags & MIPI_DSI_MODE_VSYNC_FLUSH))
			reg |= DSIM_MFLUSH_VS;
		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
			reg |= DSIM_SYNC_INFORM;
		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
			reg |= DSIM_BURST_MODE;
		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_AUTO_VERT)
			reg |= DSIM_AUTO_MODE;
		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_HSE)
			reg |= DSIM_HSE_MODE;
		if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO_HFP))
			reg |= DSIM_HFP_MODE;
		if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO_HBP))
			reg |= DSIM_HBP_MODE;
		if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO_HSA))
			reg |= DSIM_HSA_MODE;
	}

	if (!(dsi->mode_flags & MIPI_DSI_MODE_EOT_PACKET))
		reg |= DSIM_EOT_DISABLE;

	switch (dsi->format) {
	case MIPI_DSI_FMT_RGB888:
		reg |= DSIM_MAIN_PIX_FORMAT_RGB888;
		break;
	case MIPI_DSI_FMT_RGB666:
		reg |= DSIM_MAIN_PIX_FORMAT_RGB666;
		break;
	case MIPI_DSI_FMT_RGB666_PACKED:
		reg |= DSIM_MAIN_PIX_FORMAT_RGB666_P;
		break;
	case MIPI_DSI_FMT_RGB565:
		reg |= DSIM_MAIN_PIX_FORMAT_RGB565;
		break;
	default:
		dev_err(dsi->dev, "invalid pixel format\n");
		return -EINVAL;
	}

	reg |= DSIM_NUM_OF_DATA_LANE(dsi->lanes - 1);

	writel(reg, dsi->reg_base + DSIM_CONFIG_REG);

	reg |= DSIM_LANE_EN_CLK;
	writel(reg, dsi->reg_base + DSIM_CONFIG_REG);

	lanes_mask = BIT(dsi->lanes) - 1;
	reg |= DSIM_LANE_EN(lanes_mask);
	writel(reg, dsi->reg_base + DSIM_CONFIG_REG);

	/* Check clock and data lane state are stop state */
	timeout = 100;
	do {
		if (timeout-- == 0) {
			dev_err(dsi->dev, "waiting for bus lanes timed out\n");
			return -EFAULT;
		}

		reg = readl(dsi->reg_base + DSIM_STATUS_REG);
		if ((reg & DSIM_STOP_STATE_DAT(lanes_mask))
		    != DSIM_STOP_STATE_DAT(lanes_mask))
			continue;
	} while (!(reg & (DSIM_STOP_STATE_CLK | DSIM_TX_READY_HS_CLK)));

	reg = readl(dsi->reg_base + DSIM_ESCMODE_REG);
	reg &= ~DSIM_STOP_STATE_CNT_MASK;
	reg |= DSIM_STOP_STATE_CNT(0xf);
	writel(reg, dsi->reg_base + DSIM_ESCMODE_REG);

	reg = DSIM_BTA_TIMEOUT(0xff) | DSIM_LPDR_TIMEOUT(0xffff);
	writel(reg, dsi->reg_base + DSIM_TIMEOUT_REG);

	return 0;
}

static void exynos_dsi_set_display_mode(struct exynos_dsi *dsi)
{
	struct videomode *vm = &dsi->vm;
	u32 reg;

	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
		reg = DSIM_CMD_ALLOW(0xf)
			| DSIM_STABLE_VFP(vm->vfront_porch)
			| DSIM_MAIN_VBP(vm->vback_porch);
		writel(reg, dsi->reg_base + DSIM_MVPORCH_REG);

		reg = DSIM_MAIN_HFP(vm->hfront_porch)
			| DSIM_MAIN_HBP(vm->hback_porch);
		writel(reg, dsi->reg_base + DSIM_MHPORCH_REG);

		reg = DSIM_MAIN_VSA(vm->vsync_len)
			| DSIM_MAIN_HSA(vm->hsync_len);
		writel(reg, dsi->reg_base + DSIM_MSYNC_REG);
	}

	reg = DSIM_MAIN_HRESOL(vm->hactive) | DSIM_MAIN_VRESOL(vm->vactive);
	writel(reg, dsi->reg_base + DSIM_MDRESOL_REG);

	dev_dbg(dsi->dev, "LCD size = %dx%d\n", vm->hactive, vm->vactive);
}

static void exynos_dsi_set_display_enable(struct exynos_dsi *dsi, bool enable)
{
	u32 reg;

	reg = readl(dsi->reg_base + DSIM_MDRESOL_REG);
	if (enable)
		reg |= DSIM_MAIN_STAND_BY;
	else
		reg &= ~DSIM_MAIN_STAND_BY;
	writel(reg, dsi->reg_base + DSIM_MDRESOL_REG);
}

static int exynos_dsi_wait_for_hdr_fifo(struct exynos_dsi *dsi)
{
	int timeout = 2000;

	do {
		u32 reg = readl(dsi->reg_base + DSIM_FIFOCTRL_REG);

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

		if (!cond_resched())
			usleep_range(950, 1050);
	} while (--timeout);

	return -ETIMEDOUT;
}

static void exynos_dsi_set_cmd_lpm(struct exynos_dsi *dsi, bool lpm)
{
	u32 v = readl(dsi->reg_base + DSIM_ESCMODE_REG);

	if (lpm)
		v |= DSIM_CMD_LPDT_LP;
	else
		v &= ~DSIM_CMD_LPDT_LP;

	writel(v, dsi->reg_base + DSIM_ESCMODE_REG);
}

static void exynos_dsi_force_bta(struct exynos_dsi *dsi)
{
	u32 v = readl(dsi->reg_base + DSIM_ESCMODE_REG);

	v |= DSIM_FORCE_BTA;
	writel(v, dsi->reg_base + DSIM_ESCMODE_REG);
}

static void exynos_dsi_send_to_fifo(struct exynos_dsi *dsi,
					struct exynos_dsi_transfer *xfer)
{
	struct device *dev = dsi->dev;
	const u8 *payload = xfer->tx_payload + xfer->tx_done;
	u16 length = xfer->tx_len - xfer->tx_done;
	bool first = !xfer->tx_done;
	u32 reg;

	dev_dbg(dev, "< xfer %p: tx len %u, done %u, rx len %u, done %u\n",
		xfer, xfer->tx_len, xfer->tx_done, xfer->rx_len, xfer->rx_done);

	if (length > DSI_TX_FIFO_SIZE)
		length = DSI_TX_FIFO_SIZE;

	xfer->tx_done += length;

	/* Send payload */
	while (length >= 4) {
		reg = (payload[3] << 24) | (payload[2] << 16)
					| (payload[1] << 8) | payload[0];
		writel(reg, dsi->reg_base + DSIM_PAYLOAD_REG);
		payload += 4;
		length -= 4;
	}

	reg = 0;
	switch (length) {
	case 3:
		reg |= payload[2] << 16;
		/* Fall through */
	case 2:
		reg |= payload[1] << 8;
		/* Fall through */
	case 1:
		reg |= payload[0];
		writel(reg, dsi->reg_base + DSIM_PAYLOAD_REG);
		break;
	case 0:
		/* Do nothing */
		break;
	}

	/* Send packet header */
	if (!first)
		return;

	reg = (xfer->data[1] << 16) | (xfer->data[0] << 8) | xfer->data_id;
	if (exynos_dsi_wait_for_hdr_fifo(dsi)) {
		dev_err(dev, "waiting for header FIFO timed out\n");
		return;
	}

	if (NEQV(xfer->flags & MIPI_DSI_MSG_USE_LPM,
		 dsi->state & DSIM_STATE_CMD_LPM)) {
		exynos_dsi_set_cmd_lpm(dsi, xfer->flags & MIPI_DSI_MSG_USE_LPM);
		dsi->state ^= DSIM_STATE_CMD_LPM;
	}

	writel(reg, dsi->reg_base + DSIM_PKTHDR_REG);

	if (xfer->flags & MIPI_DSI_MSG_REQ_ACK)
		exynos_dsi_force_bta(dsi);
}

static void exynos_dsi_read_from_fifo(struct exynos_dsi *dsi,
					struct exynos_dsi_transfer *xfer)
{
	u8 *payload = xfer->rx_payload + xfer->rx_done;
	bool first = !xfer->rx_done;
	struct device *dev = dsi->dev;
	u16 length;
	u32 reg;

	if (first) {
		reg = readl(dsi->reg_base + DSIM_RXFIFO_REG);

		switch (reg & 0x3f) {
		case MIPI_DSI_RX_GENERIC_SHORT_READ_RESPONSE_2BYTE:
		case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_2BYTE:
			if (xfer->rx_len >= 2) {
				payload[1] = reg >> 16;
				++xfer->rx_done;
			}
			/* Fall through */
		case MIPI_DSI_RX_GENERIC_SHORT_READ_RESPONSE_1BYTE:
		case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_1BYTE:
			payload[0] = reg >> 8;
			++xfer->rx_done;
			xfer->rx_len = xfer->rx_done;
			xfer->result = 0;
			goto clear_fifo;
		case MIPI_DSI_RX_ACKNOWLEDGE_AND_ERROR_REPORT:
			dev_err(dev, "DSI Error Report: 0x%04x\n",
				(reg >> 8) & 0xffff);
			xfer->result = 0;
			goto clear_fifo;
		}

		length = (reg >> 8) & 0xffff;
		if (length > xfer->rx_len) {
			dev_err(dev,
				"response too long (%u > %u bytes), stripping\n",
				xfer->rx_len, length);
			length = xfer->rx_len;
		} else if (length < xfer->rx_len)
			xfer->rx_len = length;
	}

	length = xfer->rx_len - xfer->rx_done;
	xfer->rx_done += length;

	/* Receive payload */
	while (length >= 4) {
		reg = readl(dsi->reg_base + DSIM_RXFIFO_REG);
		payload[0] = (reg >>  0) & 0xff;
		payload[1] = (reg >>  8) & 0xff;
		payload[2] = (reg >> 16) & 0xff;
		payload[3] = (reg >> 24) & 0xff;
		payload += 4;
		length -= 4;
	}

	if (length) {
		reg = readl(dsi->reg_base + DSIM_RXFIFO_REG);
		switch (length) {
		case 3:
			payload[2] = (reg >> 16) & 0xff;
			/* Fall through */
		case 2:
			payload[1] = (reg >> 8) & 0xff;
			/* Fall through */
		case 1:
			payload[0] = reg & 0xff;
		}
	}

	if (xfer->rx_done == xfer->rx_len)
		xfer->result = 0;

clear_fifo:
	length = DSI_RX_FIFO_SIZE / 4;
	do {
		reg = readl(dsi->reg_base + DSIM_RXFIFO_REG);
		if (reg == DSI_RX_FIFO_EMPTY)
			break;
	} while (--length);
}

static void exynos_dsi_transfer_start(struct exynos_dsi *dsi)
{
	unsigned long flags;
	struct exynos_dsi_transfer *xfer;
	bool start = false;

again:
	spin_lock_irqsave(&dsi->transfer_lock, flags);

	if (list_empty(&dsi->transfer_list)) {
		spin_unlock_irqrestore(&dsi->transfer_lock, flags);
		return;
	}

	xfer = list_first_entry(&dsi->transfer_list,
					struct exynos_dsi_transfer, list);

	spin_unlock_irqrestore(&dsi->transfer_lock, flags);

	if (xfer->tx_len && xfer->tx_done == xfer->tx_len)
		/* waiting for RX */
		return;

	exynos_dsi_send_to_fifo(dsi, xfer);

	if (xfer->tx_len || xfer->rx_len)
		return;

	xfer->result = 0;
	complete(&xfer->completed);

	spin_lock_irqsave(&dsi->transfer_lock, flags);

	list_del_init(&xfer->list);
	start = !list_empty(&dsi->transfer_list);

	spin_unlock_irqrestore(&dsi->transfer_lock, flags);

	if (start)
		goto again;
}

static bool exynos_dsi_transfer_finish(struct exynos_dsi *dsi)
{
	struct exynos_dsi_transfer *xfer;
	unsigned long flags;
	bool start = true;

	spin_lock_irqsave(&dsi->transfer_lock, flags);

	if (list_empty(&dsi->transfer_list)) {
		spin_unlock_irqrestore(&dsi->transfer_lock, flags);
		return false;
	}

	xfer = list_first_entry(&dsi->transfer_list,
					struct exynos_dsi_transfer, list);

	spin_unlock_irqrestore(&dsi->transfer_lock, flags);

	dev_dbg(dsi->dev,
		"> xfer %p, tx_len %u, tx_done %u, rx_len %u, rx_done %u\n",
		xfer, xfer->tx_len, xfer->tx_done, xfer->rx_len, xfer->rx_done);

	if (xfer->tx_done != xfer->tx_len)
		return true;

	if (xfer->rx_done != xfer->rx_len)
		exynos_dsi_read_from_fifo(dsi, xfer);

	if (xfer->rx_done != xfer->rx_len)
		return true;

	spin_lock_irqsave(&dsi->transfer_lock, flags);

	list_del_init(&xfer->list);
	start = !list_empty(&dsi->transfer_list);

	spin_unlock_irqrestore(&dsi->transfer_lock, flags);

	if (!xfer->rx_len)
		xfer->result = 0;
	complete(&xfer->completed);

	return start;
}

static void exynos_dsi_remove_transfer(struct exynos_dsi *dsi,
					struct exynos_dsi_transfer *xfer)
{
	unsigned long flags;
	bool start;

	spin_lock_irqsave(&dsi->transfer_lock, flags);

	if (!list_empty(&dsi->transfer_list) &&
	    xfer == list_first_entry(&dsi->transfer_list,
				     struct exynos_dsi_transfer, list)) {
		list_del_init(&xfer->list);
		start = !list_empty(&dsi->transfer_list);
		spin_unlock_irqrestore(&dsi->transfer_lock, flags);
		if (start)
			exynos_dsi_transfer_start(dsi);
		return;
	}

	list_del_init(&xfer->list);

	spin_unlock_irqrestore(&dsi->transfer_lock, flags);
}

static int exynos_dsi_transfer(struct exynos_dsi *dsi,
					struct exynos_dsi_transfer *xfer)
{
	unsigned long flags;
	bool stopped;

	xfer->tx_done = 0;
	xfer->rx_done = 0;
	xfer->result = -ETIMEDOUT;
	init_completion(&xfer->completed);

	spin_lock_irqsave(&dsi->transfer_lock, flags);

	stopped = list_empty(&dsi->transfer_list);
	list_add_tail(&xfer->list, &dsi->transfer_list);

	spin_unlock_irqrestore(&dsi->transfer_lock, flags);

	if (stopped)
		exynos_dsi_transfer_start(dsi);

	wait_for_completion_timeout(&xfer->completed,
				    msecs_to_jiffies(DSI_XFER_TIMEOUT_MS));
	if (xfer->result == -ETIMEDOUT) {
		exynos_dsi_remove_transfer(dsi, xfer);
		dev_err(dsi->dev, "xfer timed out: %*ph %*ph\n", 2, xfer->data,
			xfer->tx_len, xfer->tx_payload);
		return -ETIMEDOUT;
	}

	/* Also covers hardware timeout condition */
	return xfer->result;
}

static irqreturn_t exynos_dsi_irq(int irq, void *dev_id)
{
	struct exynos_dsi *dsi = dev_id;
	u32 status;

	status = readl(dsi->reg_base + DSIM_INTSRC_REG);
	if (!status) {
		static unsigned long int j;
		if (printk_timed_ratelimit(&j, 500))
			dev_warn(dsi->dev, "spurious interrupt\n");
		return IRQ_HANDLED;
	}
	writel(status, dsi->reg_base + DSIM_INTSRC_REG);

	if (status & DSIM_INT_SW_RST_RELEASE) {
		u32 mask = ~(DSIM_INT_RX_DONE | DSIM_INT_SFR_FIFO_EMPTY);
		writel(mask, dsi->reg_base + DSIM_INTMSK_REG);
		complete(&dsi->completed);
		return IRQ_HANDLED;
	}

	if (!(status & (DSIM_INT_RX_DONE | DSIM_INT_SFR_FIFO_EMPTY)))
		return IRQ_HANDLED;

	if (exynos_dsi_transfer_finish(dsi))
		exynos_dsi_transfer_start(dsi);

	return IRQ_HANDLED;
}

static irqreturn_t exynos_dsi_te_irq_handler(int irq, void *dev_id)
{
	struct exynos_dsi *dsi = (struct exynos_dsi *)dev_id;
	struct drm_encoder *encoder = dsi->encoder;

	if (dsi->state & DSIM_STATE_ENABLED)
		exynos_drm_crtc_te_handler(encoder->crtc);

	return IRQ_HANDLED;
}

static void exynos_dsi_enable_irq(struct exynos_dsi *dsi)
{
	enable_irq(dsi->irq);

	if (gpio_is_valid(dsi->te_gpio))
		enable_irq(gpio_to_irq(dsi->te_gpio));
}

static void exynos_dsi_disable_irq(struct exynos_dsi *dsi)
{
	if (gpio_is_valid(dsi->te_gpio))
		disable_irq(gpio_to_irq(dsi->te_gpio));

	disable_irq(dsi->irq);
}

static int exynos_dsi_init(struct exynos_dsi *dsi)
{
	exynos_dsi_reset(dsi);
	exynos_dsi_enable_irq(dsi);
	exynos_dsi_enable_clock(dsi);
	exynos_dsi_wait_for_reset(dsi);
	exynos_dsi_set_phy_ctrl(dsi);
	exynos_dsi_init_link(dsi);

	return 0;
}

static int exynos_dsi_register_te_irq(struct exynos_dsi *dsi)
{
	int ret;

	dsi->te_gpio = of_get_named_gpio(dsi->panel_node, "te-gpios", 0);
	if (!gpio_is_valid(dsi->te_gpio)) {
		dev_err(dsi->dev, "no te-gpios specified\n");
		ret = dsi->te_gpio;
		goto out;
	}

	ret = gpio_request_one(dsi->te_gpio, GPIOF_IN, "te_gpio");
	if (ret) {
		dev_err(dsi->dev, "gpio request failed with %d\n", ret);
		goto out;
	}

	/*
	 * This TE GPIO IRQ should not be set to IRQ_NOAUTOEN, because panel
	 * calls drm_panel_init() first then calls mipi_dsi_attach() in probe().
	 * It means that te_gpio is invalid when exynos_dsi_enable_irq() is
	 * called by drm_panel_init() before panel is attached.
	 */
	ret = request_threaded_irq(gpio_to_irq(dsi->te_gpio),
					exynos_dsi_te_irq_handler, NULL,
					IRQF_TRIGGER_RISING, "TE", dsi);
	if (ret) {
		dev_err(dsi->dev, "request interrupt failed with %d\n", ret);
		gpio_free(dsi->te_gpio);
		goto out;
	}

out:
	return ret;
}

static void exynos_dsi_unregister_te_irq(struct exynos_dsi *dsi)
{
	if (gpio_is_valid(dsi->te_gpio)) {
		free_irq(gpio_to_irq(dsi->te_gpio), dsi);
		gpio_free(dsi->te_gpio);
		dsi->te_gpio = -ENOENT;
	}
}

static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
				  struct mipi_dsi_device *device)
{
	struct exynos_dsi *dsi = host_to_dsi(host);

	dsi->lanes = device->lanes;
	dsi->format = device->format;
	dsi->mode_flags = device->mode_flags;
	dsi->panel_node = device->dev.of_node;

	if (dsi->connector.dev)
		drm_helper_hpd_irq_event(dsi->connector.dev);

	/*
	 * This is a temporary solution and should be made by more generic way.
	 *
	 * If attached panel device is for command mode one, dsi should register
	 * TE interrupt handler.
	 */
	if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO)) {
		int ret = exynos_dsi_register_te_irq(dsi);

		if (ret)
			return ret;
	}

	return 0;
}

static int exynos_dsi_host_detach(struct mipi_dsi_host *host,
				  struct mipi_dsi_device *device)
{
	struct exynos_dsi *dsi = host_to_dsi(host);

	exynos_dsi_unregister_te_irq(dsi);

	dsi->panel_node = NULL;

	if (dsi->connector.dev)
		drm_helper_hpd_irq_event(dsi->connector.dev);

	return 0;
}

/* distinguish between short and long DSI packet types */
static bool exynos_dsi_is_short_dsi_type(u8 type)
{
	return (type & 0x0f) <= 8;
}

static ssize_t exynos_dsi_host_transfer(struct mipi_dsi_host *host,
				       struct mipi_dsi_msg *msg)
{
	struct exynos_dsi *dsi = host_to_dsi(host);
	struct exynos_dsi_transfer xfer;
	int ret;

	if (!(dsi->state & DSIM_STATE_INITIALIZED)) {
		ret = exynos_dsi_init(dsi);
		if (ret)
			return ret;
		dsi->state |= DSIM_STATE_INITIALIZED;
	}

	if (msg->tx_len == 0)
		return -EINVAL;

	xfer.data_id = msg->type | (msg->channel << 6);

	if (exynos_dsi_is_short_dsi_type(msg->type)) {
		const char *tx_buf = msg->tx_buf;

		if (msg->tx_len > 2)
			return -EINVAL;
		xfer.tx_len = 0;
		xfer.data[0] = tx_buf[0];
		xfer.data[1] = (msg->tx_len == 2) ? tx_buf[1] : 0;
	} else {
		xfer.tx_len = msg->tx_len;
		xfer.data[0] = msg->tx_len & 0xff;
		xfer.data[1] = msg->tx_len >> 8;
		xfer.tx_payload = msg->tx_buf;
	}

	xfer.rx_len = msg->rx_len;
	xfer.rx_payload = msg->rx_buf;
	xfer.flags = msg->flags;

	ret = exynos_dsi_transfer(dsi, &xfer);
	return (ret < 0) ? ret : xfer.rx_done;
}

static const struct mipi_dsi_host_ops exynos_dsi_ops = {
	.attach = exynos_dsi_host_attach,
	.detach = exynos_dsi_host_detach,
	.transfer = exynos_dsi_host_transfer,
};

static int exynos_dsi_poweron(struct exynos_dsi *dsi)
{
	int ret;

	ret = regulator_bulk_enable(ARRAY_SIZE(dsi->supplies), dsi->supplies);
	if (ret < 0) {
		dev_err(dsi->dev, "cannot enable regulators %d\n", ret);
		return ret;
	}

	ret = clk_prepare_enable(dsi->bus_clk);
	if (ret < 0) {
		dev_err(dsi->dev, "cannot enable bus clock %d\n", ret);
		goto err_bus_clk;
	}

	ret = clk_prepare_enable(dsi->pll_clk);
	if (ret < 0) {
		dev_err(dsi->dev, "cannot enable pll clock %d\n", ret);
		goto err_pll_clk;
	}

	ret = phy_power_on(dsi->phy);
	if (ret < 0) {
		dev_err(dsi->dev, "cannot enable phy %d\n", ret);
		goto err_phy;
	}

	return 0;

err_phy:
	clk_disable_unprepare(dsi->pll_clk);
err_pll_clk:
	clk_disable_unprepare(dsi->bus_clk);
err_bus_clk:
	regulator_bulk_disable(ARRAY_SIZE(dsi->supplies), dsi->supplies);

	return ret;
}

static void exynos_dsi_poweroff(struct exynos_dsi *dsi)
{
	int ret;

	usleep_range(10000, 20000);

	if (dsi->state & DSIM_STATE_INITIALIZED) {
		dsi->state &= ~DSIM_STATE_INITIALIZED;

		exynos_dsi_disable_clock(dsi);

		exynos_dsi_disable_irq(dsi);
	}

	dsi->state &= ~DSIM_STATE_CMD_LPM;

	phy_power_off(dsi->phy);

	clk_disable_unprepare(dsi->pll_clk);
	clk_disable_unprepare(dsi->bus_clk);

	ret = regulator_bulk_disable(ARRAY_SIZE(dsi->supplies), dsi->supplies);
	if (ret < 0)
		dev_err(dsi->dev, "cannot disable regulators %d\n", ret);
}

static int exynos_dsi_enable(struct exynos_dsi *dsi)
{
	int ret;

	if (dsi->state & DSIM_STATE_ENABLED)
		return 0;

	ret = exynos_dsi_poweron(dsi);
	if (ret < 0)
		return ret;

	ret = drm_panel_prepare(dsi->panel);
	if (ret < 0) {
		exynos_dsi_poweroff(dsi);
		return ret;
	}

	exynos_dsi_set_display_mode(dsi);
	exynos_dsi_set_display_enable(dsi, true);

	ret = drm_panel_enable(dsi->panel);
	if (ret < 0) {
		exynos_dsi_set_display_enable(dsi, false);
		drm_panel_unprepare(dsi->panel);
		exynos_dsi_poweroff(dsi);
		return ret;
	}

	dsi->state |= DSIM_STATE_ENABLED;

	return 0;
}

static void exynos_dsi_disable(struct exynos_dsi *dsi)
{
	if (!(dsi->state & DSIM_STATE_ENABLED))
		return;

	drm_panel_disable(dsi->panel);
	exynos_dsi_set_display_enable(dsi, false);
	drm_panel_unprepare(dsi->panel);
	exynos_dsi_poweroff(dsi);

	dsi->state &= ~DSIM_STATE_ENABLED;
}

static void exynos_dsi_dpms(struct exynos_drm_display *display, int mode)
{
	struct exynos_dsi *dsi = display->ctx;

	if (dsi->panel) {
		switch (mode) {
		case DRM_MODE_DPMS_ON:
			exynos_dsi_enable(dsi);
			break;
		case DRM_MODE_DPMS_STANDBY:
		case DRM_MODE_DPMS_SUSPEND:
		case DRM_MODE_DPMS_OFF:
			exynos_dsi_disable(dsi);
			break;
		default:
			break;
		}
	}
}

static enum drm_connector_status
exynos_dsi_detect(struct drm_connector *connector, bool force)
{
	struct exynos_dsi *dsi = connector_to_dsi(connector);

	if (!dsi->panel) {
		dsi->panel = of_drm_find_panel(dsi->panel_node);
		if (dsi->panel)
			drm_panel_attach(dsi->panel, &dsi->connector);
	} else if (!dsi->panel_node) {
		struct exynos_drm_display *display;

		display = platform_get_drvdata(to_platform_device(dsi->dev));
		exynos_dsi_dpms(display, DRM_MODE_DPMS_OFF);
		drm_panel_detach(dsi->panel);
		dsi->panel = NULL;
	}

	if (dsi->panel)
		return connector_status_connected;

	return connector_status_disconnected;
}

static void exynos_dsi_connector_destroy(struct drm_connector *connector)
{
}

static struct drm_connector_funcs exynos_dsi_connector_funcs = {
	.dpms = drm_helper_connector_dpms,
	.detect = exynos_dsi_detect,
	.fill_modes = drm_helper_probe_single_connector_modes,
	.destroy = exynos_dsi_connector_destroy,
};

static int exynos_dsi_get_modes(struct drm_connector *connector)
{
	struct exynos_dsi *dsi = connector_to_dsi(connector);

	if (dsi->panel)
		return dsi->panel->funcs->get_modes(dsi->panel);

	return 0;
}

static int exynos_dsi_mode_valid(struct drm_connector *connector,
				 struct drm_display_mode *mode)
{
	return MODE_OK;
}

static struct drm_encoder *
exynos_dsi_best_encoder(struct drm_connector *connector)
{
	struct exynos_dsi *dsi = connector_to_dsi(connector);

	return dsi->encoder;
}

static struct drm_connector_helper_funcs exynos_dsi_connector_helper_funcs = {
	.get_modes = exynos_dsi_get_modes,
	.mode_valid = exynos_dsi_mode_valid,
	.best_encoder = exynos_dsi_best_encoder,
};

static int exynos_dsi_create_connector(struct exynos_drm_display *display,
				       struct drm_encoder *encoder)
{
	struct exynos_dsi *dsi = display->ctx;
	struct drm_connector *connector = &dsi->connector;
	int ret;

	dsi->encoder = encoder;

	connector->polled = DRM_CONNECTOR_POLL_HPD;

	ret = drm_connector_init(encoder->dev, connector,
				 &exynos_dsi_connector_funcs,
				 DRM_MODE_CONNECTOR_DSI);
	if (ret) {
		DRM_ERROR("Failed to initialize connector with drm\n");
		return ret;
	}

	drm_connector_helper_add(connector, &exynos_dsi_connector_helper_funcs);
	drm_connector_register(connector);
	drm_mode_connector_attach_encoder(connector, encoder);

	return 0;
}

static void exynos_dsi_mode_set(struct exynos_drm_display *display,
			 struct drm_display_mode *mode)
{
	struct exynos_dsi *dsi = display->ctx;
	struct videomode *vm = &dsi->vm;

	vm->hactive = mode->hdisplay;
	vm->vactive = mode->vdisplay;
	vm->vfront_porch = mode->vsync_start - mode->vdisplay;
	vm->vback_porch = mode->vtotal - mode->vsync_end;
	vm->vsync_len = mode->vsync_end - mode->vsync_start;
	vm->hfront_porch = mode->hsync_start - mode->hdisplay;
	vm->hback_porch = mode->htotal - mode->hsync_end;
	vm->hsync_len = mode->hsync_end - mode->hsync_start;
}

static struct exynos_drm_display_ops exynos_dsi_display_ops = {
	.create_connector = exynos_dsi_create_connector,
	.mode_set = exynos_dsi_mode_set,
	.dpms = exynos_dsi_dpms
};

static struct exynos_drm_display exynos_dsi_display = {
	.type = EXYNOS_DISPLAY_TYPE_LCD,
	.ops = &exynos_dsi_display_ops,
};
MODULE_DEVICE_TABLE(of, exynos_dsi_of_match);

/* of_* functions will be removed after merge of of_graph patches */
static struct device_node *
of_get_child_by_name_reg(struct device_node *parent, const char *name, u32 reg)
{
	struct device_node *np;

	for_each_child_of_node(parent, np) {
		u32 r;

		if (!np->name || of_node_cmp(np->name, name))
			continue;

		if (of_property_read_u32(np, "reg", &r) < 0)
			r = 0;

		if (reg == r)
			break;
	}

	return np;
}

static struct device_node *of_graph_get_port_by_reg(struct device_node *parent,
						    u32 reg)
{
	struct device_node *ports, *port;

	ports = of_get_child_by_name(parent, "ports");
	if (ports)
		parent = ports;

	port = of_get_child_by_name_reg(parent, "port", reg);

	of_node_put(ports);

	return port;
}

static struct device_node *
of_graph_get_endpoint_by_reg(struct device_node *port, u32 reg)
{
	return of_get_child_by_name_reg(port, "endpoint", reg);
}

static int exynos_dsi_of_read_u32(const struct device_node *np,
				  const char *propname, u32 *out_value)
{
	int ret = of_property_read_u32(np, propname, out_value);

	if (ret < 0)
		pr_err("%s: failed to get '%s' property\n", np->full_name,
		       propname);

	return ret;
}

enum {
	DSI_PORT_IN,
	DSI_PORT_OUT
};

static int exynos_dsi_parse_dt(struct exynos_dsi *dsi)
{
	struct device *dev = dsi->dev;
	struct device_node *node = dev->of_node;
	struct device_node *port, *ep;
	int ret;

	ret = exynos_dsi_of_read_u32(node, "samsung,pll-clock-frequency",
				     &dsi->pll_clk_rate);
	if (ret < 0)
		return ret;

	port = of_graph_get_port_by_reg(node, DSI_PORT_OUT);
	if (!port) {
		dev_err(dev, "no output port specified\n");
		return -EINVAL;
	}

	ep = of_graph_get_endpoint_by_reg(port, 0);
	of_node_put(port);
	if (!ep) {
		dev_err(dev, "no endpoint specified in output port\n");
		return -EINVAL;
	}

	ret = exynos_dsi_of_read_u32(ep, "samsung,burst-clock-frequency",
				     &dsi->burst_clk_rate);
	if (ret < 0)
		goto end;

	ret = exynos_dsi_of_read_u32(ep, "samsung,esc-clock-frequency",
				     &dsi->esc_clk_rate);

end:
	of_node_put(ep);

	return ret;
}

static int exynos_dsi_bind(struct device *dev, struct device *master,
				void *data)
{
	struct drm_device *drm_dev = data;
	struct exynos_dsi *dsi;
	int ret;

	ret = exynos_drm_create_enc_conn(drm_dev, &exynos_dsi_display);
	if (ret) {
		DRM_ERROR("Encoder create [%d] failed with %d\n",
				exynos_dsi_display.type, ret);
		return ret;
	}

	dsi = exynos_dsi_display.ctx;

	return mipi_dsi_host_register(&dsi->dsi_host);
}

static void exynos_dsi_unbind(struct device *dev, struct device *master,
				void *data)
{
	struct exynos_dsi *dsi = exynos_dsi_display.ctx;
	struct drm_encoder *encoder = dsi->encoder;

	exynos_dsi_dpms(&exynos_dsi_display, DRM_MODE_DPMS_OFF);

	mipi_dsi_host_unregister(&dsi->dsi_host);

	encoder->funcs->destroy(encoder);
	drm_connector_cleanup(&dsi->connector);
}

static const struct component_ops exynos_dsi_component_ops = {
	.bind	= exynos_dsi_bind,
	.unbind	= exynos_dsi_unbind,
};

static int exynos_dsi_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct exynos_dsi *dsi;
	int ret;

	ret = exynos_drm_component_add(&pdev->dev, EXYNOS_DEVICE_TYPE_CONNECTOR,
					exynos_dsi_display.type);
	if (ret)
		return ret;

	dsi = devm_kzalloc(&pdev->dev, sizeof(*dsi), GFP_KERNEL);
	if (!dsi) {
		dev_err(&pdev->dev, "failed to allocate dsi object.\n");
		ret = -ENOMEM;
		goto err_del_component;
	}

	/* To be checked as invalid one */
	dsi->te_gpio = -ENOENT;

	init_completion(&dsi->completed);
	spin_lock_init(&dsi->transfer_lock);
	INIT_LIST_HEAD(&dsi->transfer_list);

	dsi->dsi_host.ops = &exynos_dsi_ops;
	dsi->dsi_host.dev = &pdev->dev;

	dsi->dev = &pdev->dev;
	dsi->driver_data = exynos_dsi_get_driver_data(pdev);

	ret = exynos_dsi_parse_dt(dsi);
	if (ret)
		goto err_del_component;

	dsi->supplies[0].supply = "vddcore";
	dsi->supplies[1].supply = "vddio";
	ret = devm_regulator_bulk_get(&pdev->dev, ARRAY_SIZE(dsi->supplies),
				      dsi->supplies);
	if (ret) {
		dev_info(&pdev->dev, "failed to get regulators: %d\n", ret);
		return -EPROBE_DEFER;
	}

	dsi->pll_clk = devm_clk_get(&pdev->dev, "pll_clk");
	if (IS_ERR(dsi->pll_clk)) {
		dev_info(&pdev->dev, "failed to get dsi pll input clock\n");
		ret = PTR_ERR(dsi->pll_clk);
		goto err_del_component;
	}

	dsi->bus_clk = devm_clk_get(&pdev->dev, "bus_clk");
	if (IS_ERR(dsi->bus_clk)) {
		dev_info(&pdev->dev, "failed to get dsi bus clock\n");
		ret = PTR_ERR(dsi->bus_clk);
		goto err_del_component;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	dsi->reg_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(dsi->reg_base)) {
		dev_err(&pdev->dev, "failed to remap io region\n");
		ret = PTR_ERR(dsi->reg_base);
		goto err_del_component;
	}

	dsi->phy = devm_phy_get(&pdev->dev, "dsim");
	if (IS_ERR(dsi->phy)) {
		dev_info(&pdev->dev, "failed to get dsim phy\n");
		ret = PTR_ERR(dsi->phy);
		goto err_del_component;
	}

	dsi->irq = platform_get_irq(pdev, 0);
	if (dsi->irq < 0) {
		dev_err(&pdev->dev, "failed to request dsi irq resource\n");
		ret = dsi->irq;
		goto err_del_component;
	}

	irq_set_status_flags(dsi->irq, IRQ_NOAUTOEN);
	ret = devm_request_threaded_irq(&pdev->dev, dsi->irq, NULL,
					exynos_dsi_irq, IRQF_ONESHOT,
					dev_name(&pdev->dev), dsi);
	if (ret) {
		dev_err(&pdev->dev, "failed to request dsi irq\n");
		goto err_del_component;
	}

	exynos_dsi_display.ctx = dsi;

	platform_set_drvdata(pdev, &exynos_dsi_display);

	ret = component_add(&pdev->dev, &exynos_dsi_component_ops);
	if (ret)
		goto err_del_component;

	return ret;

err_del_component:
	exynos_drm_component_del(&pdev->dev, EXYNOS_DEVICE_TYPE_CONNECTOR);
	return ret;
}

static int exynos_dsi_remove(struct platform_device *pdev)
{
	component_del(&pdev->dev, &exynos_dsi_component_ops);
	exynos_drm_component_del(&pdev->dev, EXYNOS_DEVICE_TYPE_CONNECTOR);

	return 0;
}

struct platform_driver dsi_driver = {
	.probe = exynos_dsi_probe,
	.remove = exynos_dsi_remove,
	.driver = {
		   .name = "exynos-dsi",
		   .owner = THIS_MODULE,
		   .of_match_table = exynos_dsi_of_match,
	},
};

MODULE_AUTHOR("Tomasz Figa <t.figa@samsung.com>");
MODULE_AUTHOR("Andrzej Hajda <a.hajda@samsung.com>");
MODULE_DESCRIPTION("Samsung SoC MIPI DSI Master");
MODULE_LICENSE("GPL v2");