/*
 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only 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/delay.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/pinctrl/consumer.h>
#include <linux/of_graph.h>
#include <linux/regulator/consumer.h>
#include <linux/spinlock.h>
#include <video/mipi_display.h>

#include "dsi.h"
#include "dsi.xml.h"
#include "dsi_cfg.h"

static int dsi_get_version(const void __iomem *base, u32 *major, u32 *minor)
{
        u32 ver;
        u32 ver_6g;

        if (!major || !minor)
                return -EINVAL;

        /* From DSI6G(v3), addition of a 6G_HW_VERSION register at offset 0
         * makes all other registers 4-byte shifted down.
         */
        ver_6g = msm_readl(base + REG_DSI_6G_HW_VERSION);
        if (ver_6g == 0) {
                ver = msm_readl(base + REG_DSI_VERSION);
                ver = FIELD(ver, DSI_VERSION_MAJOR);
                if (ver <= MSM_DSI_VER_MAJOR_V2) {
                        /* old versions */
                        *major = ver;
                        *minor = 0;
                        return 0;
                } else {
                        return -EINVAL;
                }
        } else {
                ver = msm_readl(base + DSI_6G_REG_SHIFT + REG_DSI_VERSION);
                ver = FIELD(ver, DSI_VERSION_MAJOR);
                if (ver == MSM_DSI_VER_MAJOR_6G) {
                        /* 6G version */
                        *major = ver;
                        *minor = ver_6g;
                        return 0;
                } else {
                        return -EINVAL;
                }
        }
}

#define DSI_ERR_STATE_ACK                       0x0000
#define DSI_ERR_STATE_TIMEOUT                   0x0001
#define DSI_ERR_STATE_DLN0_PHY                  0x0002
#define DSI_ERR_STATE_FIFO                      0x0004
#define DSI_ERR_STATE_MDP_FIFO_UNDERFLOW        0x0008
#define DSI_ERR_STATE_INTERLEAVE_OP_CONTENTION  0x0010
#define DSI_ERR_STATE_PLL_UNLOCKED              0x0020

#define DSI_CLK_CTRL_ENABLE_CLKS        \
                (DSI_CLK_CTRL_AHBS_HCLK_ON | DSI_CLK_CTRL_AHBM_SCLK_ON | \
                DSI_CLK_CTRL_PCLK_ON | DSI_CLK_CTRL_DSICLK_ON | \
                DSI_CLK_CTRL_BYTECLK_ON | DSI_CLK_CTRL_ESCCLK_ON | \
                DSI_CLK_CTRL_FORCE_ON_DYN_AHBM_HCLK)

struct msm_dsi_host {
        struct mipi_dsi_host base;

        struct platform_device *pdev;
        struct drm_device *dev;

        int id;

        void __iomem *ctrl_base;
        struct regulator_bulk_data supplies[DSI_DEV_REGULATOR_MAX];
        struct clk *mdp_core_clk;
        struct clk *ahb_clk;
        struct clk *axi_clk;
        struct clk *mmss_misc_ahb_clk;
        struct clk *byte_clk;
        struct clk *esc_clk;
        struct clk *pixel_clk;
        struct clk *byte_clk_src;
        struct clk *pixel_clk_src;

        u32 byte_clk_rate;

        struct gpio_desc *disp_en_gpio;
        struct gpio_desc *te_gpio;

        const struct msm_dsi_cfg_handler *cfg_hnd;

        struct completion dma_comp;
        struct completion video_comp;
        struct mutex dev_mutex;
        struct mutex cmd_mutex;
        struct mutex clk_mutex;
        spinlock_t intr_lock; /* Protect interrupt ctrl register */

        u32 err_work_state;
        struct work_struct err_work;
        struct workqueue_struct *workqueue;

        struct drm_gem_object *tx_gem_obj;
        u8 *rx_buf;

        struct drm_display_mode *mode;

        /* connected device info */
        struct device_node *device_node;
        unsigned int channel;
        unsigned int lanes;
        enum mipi_dsi_pixel_format format;
        unsigned long mode_flags;

        u32 dma_cmd_ctrl_restore;

        bool registered;
        bool power_on;
        int irq;
};

static u32 dsi_get_bpp(const enum mipi_dsi_pixel_format fmt)
{
        switch (fmt) {
        case MIPI_DSI_FMT_RGB565:               return 16;
        case MIPI_DSI_FMT_RGB666_PACKED:        return 18;
        case MIPI_DSI_FMT_RGB666:
        case MIPI_DSI_FMT_RGB888:
        default:                                return 24;
        }
}

static inline u32 dsi_read(struct msm_dsi_host *msm_host, u32 reg)
{
        return msm_readl(msm_host->ctrl_base + reg);
}
static inline void dsi_write(struct msm_dsi_host *msm_host, u32 reg, u32 data)
{
        msm_writel(data, msm_host->ctrl_base + reg);
}

static int dsi_host_regulator_enable(struct msm_dsi_host *msm_host);
static void dsi_host_regulator_disable(struct msm_dsi_host *msm_host);

static const struct msm_dsi_cfg_handler *dsi_get_config(
                                                struct msm_dsi_host *msm_host)
{
        const struct msm_dsi_cfg_handler *cfg_hnd = NULL;
        struct regulator *gdsc_reg;
        int ret;
        u32 major = 0, minor = 0;

        gdsc_reg = regulator_get(&msm_host->pdev->dev, "gdsc");
        if (IS_ERR(gdsc_reg)) {
                pr_err("%s: cannot get gdsc\n", __func__);
                goto exit;
        }
        ret = regulator_enable(gdsc_reg);
        if (ret) {
                pr_err("%s: unable to enable gdsc\n", __func__);
                goto put_gdsc;
        }
        ret = clk_prepare_enable(msm_host->ahb_clk);
        if (ret) {
                pr_err("%s: unable to enable ahb_clk\n", __func__);
                goto disable_gdsc;
        }

        ret = dsi_get_version(msm_host->ctrl_base, &major, &minor);
        if (ret) {
                pr_err("%s: Invalid version\n", __func__);
                goto disable_clks;
        }

        cfg_hnd = msm_dsi_cfg_get(major, minor);

        DBG("%s: Version %x:%x\n", __func__, major, minor);

disable_clks:
        clk_disable_unprepare(msm_host->ahb_clk);
disable_gdsc:
        regulator_disable(gdsc_reg);
put_gdsc:
        regulator_put(gdsc_reg);
exit:
        return cfg_hnd;
}

static inline struct msm_dsi_host *to_msm_dsi_host(struct mipi_dsi_host *host)
{
        return container_of(host, struct msm_dsi_host, base);
}

static void dsi_host_regulator_disable(struct msm_dsi_host *msm_host)
{
        struct regulator_bulk_data *s = msm_host->supplies;
        const struct dsi_reg_entry *regs = msm_host->cfg_hnd->cfg->reg_cfg.regs;
        int num = msm_host->cfg_hnd->cfg->reg_cfg.num;
        int i;

        DBG("");
        for (i = num - 1; i >= 0; i--)
                if (regs[i].disable_load >= 0)
                        regulator_set_load(s[i].consumer,
                                           regs[i].disable_load);

        regulator_bulk_disable(num, s);
}

static int dsi_host_regulator_enable(struct msm_dsi_host *msm_host)
{
        struct regulator_bulk_data *s = msm_host->supplies;
        const struct dsi_reg_entry *regs = msm_host->cfg_hnd->cfg->reg_cfg.regs;
        int num = msm_host->cfg_hnd->cfg->reg_cfg.num;
        int ret, i;

        DBG("");
        for (i = 0; i < num; i++) {
                if (regs[i].enable_load >= 0) {
                        ret = regulator_set_load(s[i].consumer,
                                                 regs[i].enable_load);
                        if (ret < 0) {
                                pr_err("regulator %d set op mode failed, %d\n",
                                        i, ret);
                                goto fail;
                        }
                }
        }

        ret = regulator_bulk_enable(num, s);
        if (ret < 0) {
                pr_err("regulator enable failed, %d\n", ret);
                goto fail;
        }

        return 0;

fail:
        for (i--; i >= 0; i--)
                regulator_set_load(s[i].consumer, regs[i].disable_load);
        return ret;
}

static int dsi_regulator_init(struct msm_dsi_host *msm_host)
{
        struct regulator_bulk_data *s = msm_host->supplies;
        const struct dsi_reg_entry *regs = msm_host->cfg_hnd->cfg->reg_cfg.regs;
        int num = msm_host->cfg_hnd->cfg->reg_cfg.num;
        int i, ret;

        for (i = 0; i < num; i++)
                s[i].supply = regs[i].name;

        ret = devm_regulator_bulk_get(&msm_host->pdev->dev, num, s);
        if (ret < 0) {
                pr_err("%s: failed to init regulator, ret=%d\n",
                                                __func__, ret);
                return ret;
        }

        for (i = 0; i < num; i++) {
                if ((regs[i].min_voltage >= 0) && (regs[i].max_voltage >= 0)) {
                        ret = regulator_set_voltage(s[i].consumer,
                                regs[i].min_voltage, regs[i].max_voltage);
                        if (ret < 0) {
                                pr_err("regulator %d set voltage failed, %d\n",
                                        i, ret);
                                return ret;
                        }
                }
        }

        return 0;
}

static int dsi_clk_init(struct msm_dsi_host *msm_host)
{
        struct device *dev = &msm_host->pdev->dev;
        int ret = 0;

        msm_host->mdp_core_clk = devm_clk_get(dev, "mdp_core_clk");
        if (IS_ERR(msm_host->mdp_core_clk)) {
                ret = PTR_ERR(msm_host->mdp_core_clk);
                pr_err("%s: Unable to get mdp core clk. ret=%d\n",
                        __func__, ret);
                goto exit;
        }

        msm_host->ahb_clk = devm_clk_get(dev, "iface_clk");
        if (IS_ERR(msm_host->ahb_clk)) {
                ret = PTR_ERR(msm_host->ahb_clk);
                pr_err("%s: Unable to get mdss ahb clk. ret=%d\n",
                        __func__, ret);
                goto exit;
        }

        msm_host->axi_clk = devm_clk_get(dev, "bus_clk");
        if (IS_ERR(msm_host->axi_clk)) {
                ret = PTR_ERR(msm_host->axi_clk);
                pr_err("%s: Unable to get axi bus clk. ret=%d\n",
                        __func__, ret);
                goto exit;
        }

        msm_host->mmss_misc_ahb_clk = devm_clk_get(dev, "core_mmss_clk");
        if (IS_ERR(msm_host->mmss_misc_ahb_clk)) {
                ret = PTR_ERR(msm_host->mmss_misc_ahb_clk);
                pr_err("%s: Unable to get mmss misc ahb clk. ret=%d\n",
                        __func__, ret);
                goto exit;
        }

        msm_host->byte_clk = devm_clk_get(dev, "byte_clk");
        if (IS_ERR(msm_host->byte_clk)) {
                ret = PTR_ERR(msm_host->byte_clk);
                pr_err("%s: can't find dsi_byte_clk. ret=%d\n",
                        __func__, ret);
                msm_host->byte_clk = NULL;
                goto exit;
        }

        msm_host->pixel_clk = devm_clk_get(dev, "pixel_clk");
        if (IS_ERR(msm_host->pixel_clk)) {
                ret = PTR_ERR(msm_host->pixel_clk);
                pr_err("%s: can't find dsi_pixel_clk. ret=%d\n",
                        __func__, ret);
                msm_host->pixel_clk = NULL;
                goto exit;
        }

        msm_host->esc_clk = devm_clk_get(dev, "core_clk");
        if (IS_ERR(msm_host->esc_clk)) {
                ret = PTR_ERR(msm_host->esc_clk);
                pr_err("%s: can't find dsi_esc_clk. ret=%d\n",
                        __func__, ret);
                msm_host->esc_clk = NULL;
                goto exit;
        }

        msm_host->byte_clk_src = devm_clk_get(dev, "byte_clk_src");
        if (IS_ERR(msm_host->byte_clk_src)) {
                ret = PTR_ERR(msm_host->byte_clk_src);
                pr_err("%s: can't find byte_clk_src. ret=%d\n", __func__, ret);
                msm_host->byte_clk_src = NULL;
                goto exit;
        }

        msm_host->pixel_clk_src = devm_clk_get(dev, "pixel_clk_src");
        if (IS_ERR(msm_host->pixel_clk_src)) {
                ret = PTR_ERR(msm_host->pixel_clk_src);
                pr_err("%s: can't find pixel_clk_src. ret=%d\n", __func__, ret);
                msm_host->pixel_clk_src = NULL;
                goto exit;
        }

exit:
        return ret;
}

static int dsi_bus_clk_enable(struct msm_dsi_host *msm_host)
{
        int ret;

        DBG("id=%d", msm_host->id);

        ret = clk_prepare_enable(msm_host->mdp_core_clk);
        if (ret) {
                pr_err("%s: failed to enable mdp_core_clock, %d\n",
                                                         __func__, ret);
                goto core_clk_err;
        }

        ret = clk_prepare_enable(msm_host->ahb_clk);
        if (ret) {
                pr_err("%s: failed to enable ahb clock, %d\n", __func__, ret);
                goto ahb_clk_err;
        }

        ret = clk_prepare_enable(msm_host->axi_clk);
        if (ret) {
                pr_err("%s: failed to enable ahb clock, %d\n", __func__, ret);
                goto axi_clk_err;
        }

        ret = clk_prepare_enable(msm_host->mmss_misc_ahb_clk);
        if (ret) {
                pr_err("%s: failed to enable mmss misc ahb clk, %d\n",
                        __func__, ret);
                goto misc_ahb_clk_err;
        }

        return 0;

misc_ahb_clk_err:
        clk_disable_unprepare(msm_host->axi_clk);
axi_clk_err:
        clk_disable_unprepare(msm_host->ahb_clk);
ahb_clk_err:
        clk_disable_unprepare(msm_host->mdp_core_clk);
core_clk_err:
        return ret;
}

static void dsi_bus_clk_disable(struct msm_dsi_host *msm_host)
{
        DBG("");
        clk_disable_unprepare(msm_host->mmss_misc_ahb_clk);
        clk_disable_unprepare(msm_host->axi_clk);
        clk_disable_unprepare(msm_host->ahb_clk);
        clk_disable_unprepare(msm_host->mdp_core_clk);
}

static int dsi_link_clk_enable(struct msm_dsi_host *msm_host)
{
        int ret;

        DBG("Set clk rates: pclk=%d, byteclk=%d",
                msm_host->mode->clock, msm_host->byte_clk_rate);

        ret = clk_set_rate(msm_host->byte_clk, msm_host->byte_clk_rate);
        if (ret) {
                pr_err("%s: Failed to set rate byte clk, %d\n", __func__, ret);
                goto error;
        }

        ret = clk_set_rate(msm_host->pixel_clk, msm_host->mode->clock * 1000);
        if (ret) {
                pr_err("%s: Failed to set rate pixel clk, %d\n", __func__, ret);
                goto error;
        }

        ret = clk_prepare_enable(msm_host->esc_clk);
        if (ret) {
                pr_err("%s: Failed to enable dsi esc clk\n", __func__);
                goto error;
        }

        ret = clk_prepare_enable(msm_host->byte_clk);
        if (ret) {
                pr_err("%s: Failed to enable dsi byte clk\n", __func__);
                goto byte_clk_err;
        }

        ret = clk_prepare_enable(msm_host->pixel_clk);
        if (ret) {
                pr_err("%s: Failed to enable dsi pixel clk\n", __func__);
                goto pixel_clk_err;
        }

        return 0;

pixel_clk_err:
        clk_disable_unprepare(msm_host->byte_clk);
byte_clk_err:
        clk_disable_unprepare(msm_host->esc_clk);
error:
        return ret;
}

static void dsi_link_clk_disable(struct msm_dsi_host *msm_host)
{
        clk_disable_unprepare(msm_host->esc_clk);
        clk_disable_unprepare(msm_host->pixel_clk);
        clk_disable_unprepare(msm_host->byte_clk);
}

static int dsi_clk_ctrl(struct msm_dsi_host *msm_host, bool enable)
{
        int ret = 0;

        mutex_lock(&msm_host->clk_mutex);
        if (enable) {
                ret = dsi_bus_clk_enable(msm_host);
                if (ret) {
                        pr_err("%s: Can not enable bus clk, %d\n",
                                __func__, ret);
                        goto unlock_ret;
                }
                ret = dsi_link_clk_enable(msm_host);
                if (ret) {
                        pr_err("%s: Can not enable link clk, %d\n",
                                __func__, ret);
                        dsi_bus_clk_disable(msm_host);
                        goto unlock_ret;
                }
        } else {
                dsi_link_clk_disable(msm_host);
                dsi_bus_clk_disable(msm_host);
        }

unlock_ret:
        mutex_unlock(&msm_host->clk_mutex);
        return ret;
}

static int dsi_calc_clk_rate(struct msm_dsi_host *msm_host)
{
        struct drm_display_mode *mode = msm_host->mode;
        u8 lanes = msm_host->lanes;
        u32 bpp = dsi_get_bpp(msm_host->format);
        u32 pclk_rate;

        if (!mode) {
                pr_err("%s: mode not set\n", __func__);
                return -EINVAL;
        }

        pclk_rate = mode->clock * 1000;
        if (lanes > 0) {
                msm_host->byte_clk_rate = (pclk_rate * bpp) / (8 * lanes);
        } else {
                pr_err("%s: forcing mdss_dsi lanes to 1\n", __func__);
                msm_host->byte_clk_rate = (pclk_rate * bpp) / 8;
        }

        DBG("pclk=%d, bclk=%d", pclk_rate, msm_host->byte_clk_rate);

        return 0;
}

static void dsi_phy_sw_reset(struct msm_dsi_host *msm_host)
{
        DBG("");
        dsi_write(msm_host, REG_DSI_PHY_RESET, DSI_PHY_RESET_RESET);
        /* Make sure fully reset */
        wmb();
        udelay(1000);
        dsi_write(msm_host, REG_DSI_PHY_RESET, 0);
        udelay(100);
}

static void dsi_intr_ctrl(struct msm_dsi_host *msm_host, u32 mask, int enable)
{
        u32 intr;
        unsigned long flags;

        spin_lock_irqsave(&msm_host->intr_lock, flags);
        intr = dsi_read(msm_host, REG_DSI_INTR_CTRL);

        if (enable)
                intr |= mask;
        else
                intr &= ~mask;

        DBG("intr=%x enable=%d", intr, enable);

        dsi_write(msm_host, REG_DSI_INTR_CTRL, intr);
        spin_unlock_irqrestore(&msm_host->intr_lock, flags);
}

static inline enum dsi_traffic_mode dsi_get_traffic_mode(const u32 mode_flags)
{
        if (mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
                return BURST_MODE;
        else if (mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
                return NON_BURST_SYNCH_PULSE;

        return NON_BURST_SYNCH_EVENT;
}

static inline enum dsi_vid_dst_format dsi_get_vid_fmt(
                                const enum mipi_dsi_pixel_format mipi_fmt)
{
        switch (mipi_fmt) {
        case MIPI_DSI_FMT_RGB888:       return VID_DST_FORMAT_RGB888;
        case MIPI_DSI_FMT_RGB666:       return VID_DST_FORMAT_RGB666_LOOSE;
        case MIPI_DSI_FMT_RGB666_PACKED:        return VID_DST_FORMAT_RGB666;
        case MIPI_DSI_FMT_RGB565:       return VID_DST_FORMAT_RGB565;
        default:                        return VID_DST_FORMAT_RGB888;
        }
}

static inline enum dsi_cmd_dst_format dsi_get_cmd_fmt(
                                const enum mipi_dsi_pixel_format mipi_fmt)
{
        switch (mipi_fmt) {
        case MIPI_DSI_FMT_RGB888:       return CMD_DST_FORMAT_RGB888;
        case MIPI_DSI_FMT_RGB666_PACKED:
        case MIPI_DSI_FMT_RGB666:       return VID_DST_FORMAT_RGB666;
        case MIPI_DSI_FMT_RGB565:       return CMD_DST_FORMAT_RGB565;
        default:                        return CMD_DST_FORMAT_RGB888;
        }
}

static void dsi_ctrl_config(struct msm_dsi_host *msm_host, bool enable,
                                u32 clk_pre, u32 clk_post)
{
        u32 flags = msm_host->mode_flags;
        enum mipi_dsi_pixel_format mipi_fmt = msm_host->format;
        const struct msm_dsi_cfg_handler *cfg_hnd = msm_host->cfg_hnd;
        u32 data = 0;

        if (!enable) {
                dsi_write(msm_host, REG_DSI_CTRL, 0);
                return;
        }

        if (flags & MIPI_DSI_MODE_VIDEO) {
                if (flags & MIPI_DSI_MODE_VIDEO_HSE)
                        data |= DSI_VID_CFG0_PULSE_MODE_HSA_HE;
                if (flags & MIPI_DSI_MODE_VIDEO_HFP)
                        data |= DSI_VID_CFG0_HFP_POWER_STOP;
                if (flags & MIPI_DSI_MODE_VIDEO_HBP)
                        data |= DSI_VID_CFG0_HBP_POWER_STOP;
                if (flags & MIPI_DSI_MODE_VIDEO_HSA)
                        data |= DSI_VID_CFG0_HSA_POWER_STOP;
                /* Always set low power stop mode for BLLP
                 * to let command engine send packets
                 */
                data |= DSI_VID_CFG0_EOF_BLLP_POWER_STOP |
                        DSI_VID_CFG0_BLLP_POWER_STOP;
                data |= DSI_VID_CFG0_TRAFFIC_MODE(dsi_get_traffic_mode(flags));
                data |= DSI_VID_CFG0_DST_FORMAT(dsi_get_vid_fmt(mipi_fmt));
                data |= DSI_VID_CFG0_VIRT_CHANNEL(msm_host->channel);
                dsi_write(msm_host, REG_DSI_VID_CFG0, data);

                /* Do not swap RGB colors */
                data = DSI_VID_CFG1_RGB_SWAP(SWAP_RGB);
                dsi_write(msm_host, REG_DSI_VID_CFG1, 0);
        } else {
                /* Do not swap RGB colors */
                data = DSI_CMD_CFG0_RGB_SWAP(SWAP_RGB);
                data |= DSI_CMD_CFG0_DST_FORMAT(dsi_get_cmd_fmt(mipi_fmt));
                dsi_write(msm_host, REG_DSI_CMD_CFG0, data);

                data = DSI_CMD_CFG1_WR_MEM_START(MIPI_DCS_WRITE_MEMORY_START) |
                        DSI_CMD_CFG1_WR_MEM_CONTINUE(
                                        MIPI_DCS_WRITE_MEMORY_CONTINUE);
                /* Always insert DCS command */
                data |= DSI_CMD_CFG1_INSERT_DCS_COMMAND;
                dsi_write(msm_host, REG_DSI_CMD_CFG1, data);
        }

        dsi_write(msm_host, REG_DSI_CMD_DMA_CTRL,
                        DSI_CMD_DMA_CTRL_FROM_FRAME_BUFFER |
                        DSI_CMD_DMA_CTRL_LOW_POWER);

        data = 0;
        /* Always assume dedicated TE pin */
        data |= DSI_TRIG_CTRL_TE;
        data |= DSI_TRIG_CTRL_MDP_TRIGGER(TRIGGER_NONE);
        data |= DSI_TRIG_CTRL_DMA_TRIGGER(TRIGGER_SW);
        data |= DSI_TRIG_CTRL_STREAM(msm_host->channel);
        if ((cfg_hnd->major == MSM_DSI_VER_MAJOR_6G) &&
                (cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V1_2))
                data |= DSI_TRIG_CTRL_BLOCK_DMA_WITHIN_FRAME;
        dsi_write(msm_host, REG_DSI_TRIG_CTRL, data);

        data = DSI_CLKOUT_TIMING_CTRL_T_CLK_POST(clk_post) |
                DSI_CLKOUT_TIMING_CTRL_T_CLK_PRE(clk_pre);
        dsi_write(msm_host, REG_DSI_CLKOUT_TIMING_CTRL, data);

        data = 0;
        if (!(flags & MIPI_DSI_MODE_EOT_PACKET))
                data |= DSI_EOT_PACKET_CTRL_TX_EOT_APPEND;
        dsi_write(msm_host, REG_DSI_EOT_PACKET_CTRL, data);

        /* allow only ack-err-status to generate interrupt */
        dsi_write(msm_host, REG_DSI_ERR_INT_MASK0, 0x13ff3fe0);

        dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_ERROR, 1);

        dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);

        data = DSI_CTRL_CLK_EN;

        DBG("lane number=%d", msm_host->lanes);
        if (msm_host->lanes == 2) {
                data |= DSI_CTRL_LANE1 | DSI_CTRL_LANE2;
                /* swap lanes for 2-lane panel for better performance */
                dsi_write(msm_host, REG_DSI_LANE_SWAP_CTRL,
                        DSI_LANE_SWAP_CTRL_DLN_SWAP_SEL(LANE_SWAP_1230));
        } else {
                /* Take 4 lanes as default */
                data |= DSI_CTRL_LANE0 | DSI_CTRL_LANE1 | DSI_CTRL_LANE2 |
                        DSI_CTRL_LANE3;
                /* Do not swap lanes for 4-lane panel */
                dsi_write(msm_host, REG_DSI_LANE_SWAP_CTRL,
                        DSI_LANE_SWAP_CTRL_DLN_SWAP_SEL(LANE_SWAP_0123));
        }

        if (!(flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
                dsi_write(msm_host, REG_DSI_LANE_CTRL,
                        DSI_LANE_CTRL_CLKLN_HS_FORCE_REQUEST);

        data |= DSI_CTRL_ENABLE;

        dsi_write(msm_host, REG_DSI_CTRL, data);
}

static void dsi_timing_setup(struct msm_dsi_host *msm_host)
{
        struct drm_display_mode *mode = msm_host->mode;
        u32 hs_start = 0, vs_start = 0; /* take sync start as 0 */
        u32 h_total = mode->htotal;
        u32 v_total = mode->vtotal;
        u32 hs_end = mode->hsync_end - mode->hsync_start;
        u32 vs_end = mode->vsync_end - mode->vsync_start;
        u32 ha_start = h_total - mode->hsync_start;
        u32 ha_end = ha_start + mode->hdisplay;
        u32 va_start = v_total - mode->vsync_start;
        u32 va_end = va_start + mode->vdisplay;
        u32 wc;

        DBG("");

        if (msm_host->mode_flags & MIPI_DSI_MODE_VIDEO) {
                dsi_write(msm_host, REG_DSI_ACTIVE_H,
                        DSI_ACTIVE_H_START(ha_start) |
                        DSI_ACTIVE_H_END(ha_end));
                dsi_write(msm_host, REG_DSI_ACTIVE_V,
                        DSI_ACTIVE_V_START(va_start) |
                        DSI_ACTIVE_V_END(va_end));
                dsi_write(msm_host, REG_DSI_TOTAL,
                        DSI_TOTAL_H_TOTAL(h_total - 1) |
                        DSI_TOTAL_V_TOTAL(v_total - 1));

                dsi_write(msm_host, REG_DSI_ACTIVE_HSYNC,
                        DSI_ACTIVE_HSYNC_START(hs_start) |
                        DSI_ACTIVE_HSYNC_END(hs_end));
                dsi_write(msm_host, REG_DSI_ACTIVE_VSYNC_HPOS, 0);
                dsi_write(msm_host, REG_DSI_ACTIVE_VSYNC_VPOS,
                        DSI_ACTIVE_VSYNC_VPOS_START(vs_start) |
                        DSI_ACTIVE_VSYNC_VPOS_END(vs_end));
        } else {                /* command mode */
                /* image data and 1 byte write_memory_start cmd */
                wc = mode->hdisplay * dsi_get_bpp(msm_host->format) / 8 + 1;

                dsi_write(msm_host, REG_DSI_CMD_MDP_STREAM_CTRL,
                        DSI_CMD_MDP_STREAM_CTRL_WORD_COUNT(wc) |
                        DSI_CMD_MDP_STREAM_CTRL_VIRTUAL_CHANNEL(
                                        msm_host->channel) |
                        DSI_CMD_MDP_STREAM_CTRL_DATA_TYPE(
                                        MIPI_DSI_DCS_LONG_WRITE));

                dsi_write(msm_host, REG_DSI_CMD_MDP_STREAM_TOTAL,
                        DSI_CMD_MDP_STREAM_TOTAL_H_TOTAL(mode->hdisplay) |
                        DSI_CMD_MDP_STREAM_TOTAL_V_TOTAL(mode->vdisplay));
        }
}

static void dsi_sw_reset(struct msm_dsi_host *msm_host)
{
        dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);
        wmb(); /* clocks need to be enabled before reset */

        dsi_write(msm_host, REG_DSI_RESET, 1);
        wmb(); /* make sure reset happen */
        dsi_write(msm_host, REG_DSI_RESET, 0);
}

static void dsi_op_mode_config(struct msm_dsi_host *msm_host,
                                        bool video_mode, bool enable)
{
        u32 dsi_ctrl;

        dsi_ctrl = dsi_read(msm_host, REG_DSI_CTRL);

        if (!enable) {
                dsi_ctrl &= ~(DSI_CTRL_ENABLE | DSI_CTRL_VID_MODE_EN |
                                DSI_CTRL_CMD_MODE_EN);
                dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_CMD_MDP_DONE |
                                        DSI_IRQ_MASK_VIDEO_DONE, 0);
        } else {
                if (video_mode) {
                        dsi_ctrl |= DSI_CTRL_VID_MODE_EN;
                } else {                /* command mode */
                        dsi_ctrl |= DSI_CTRL_CMD_MODE_EN;
                        dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_CMD_MDP_DONE, 1);
                }
                dsi_ctrl |= DSI_CTRL_ENABLE;
        }

        dsi_write(msm_host, REG_DSI_CTRL, dsi_ctrl);
}

static void dsi_set_tx_power_mode(int mode, struct msm_dsi_host *msm_host)
{
        u32 data;

        data = dsi_read(msm_host, REG_DSI_CMD_DMA_CTRL);

        if (mode == 0)
                data &= ~DSI_CMD_DMA_CTRL_LOW_POWER;
        else
                data |= DSI_CMD_DMA_CTRL_LOW_POWER;

        dsi_write(msm_host, REG_DSI_CMD_DMA_CTRL, data);
}

static void dsi_wait4video_done(struct msm_dsi_host *msm_host)
{
        dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_VIDEO_DONE, 1);

        reinit_completion(&msm_host->video_comp);

        wait_for_completion_timeout(&msm_host->video_comp,
                        msecs_to_jiffies(70));

        dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_VIDEO_DONE, 0);
}

static void dsi_wait4video_eng_busy(struct msm_dsi_host *msm_host)
{
        if (!(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO))
                return;

        if (msm_host->power_on) {
                dsi_wait4video_done(msm_host);
                /* delay 4 ms to skip BLLP */
                usleep_range(2000, 4000);
        }
}

/* dsi_cmd */
static int dsi_tx_buf_alloc(struct msm_dsi_host *msm_host, int size)
{
        struct drm_device *dev = msm_host->dev;
        int ret;
        u32 iova;

        mutex_lock(&dev->struct_mutex);
        msm_host->tx_gem_obj = msm_gem_new(dev, size, MSM_BO_UNCACHED);
        if (IS_ERR(msm_host->tx_gem_obj)) {
                ret = PTR_ERR(msm_host->tx_gem_obj);
                pr_err("%s: failed to allocate gem, %d\n", __func__, ret);
                msm_host->tx_gem_obj = NULL;
                mutex_unlock(&dev->struct_mutex);
                return ret;
        }

        ret = msm_gem_get_iova_locked(msm_host->tx_gem_obj, 0, &iova);
        if (ret) {
                pr_err("%s: failed to get iova, %d\n", __func__, ret);
                return ret;
        }
        mutex_unlock(&dev->struct_mutex);

        if (iova & 0x07) {
                pr_err("%s: buf NOT 8 bytes aligned\n", __func__);
                return -EINVAL;
        }

        return 0;
}

static void dsi_tx_buf_free(struct msm_dsi_host *msm_host)
{
        struct drm_device *dev = msm_host->dev;

        if (msm_host->tx_gem_obj) {
                msm_gem_put_iova(msm_host->tx_gem_obj, 0);
                mutex_lock(&dev->struct_mutex);
                msm_gem_free_object(msm_host->tx_gem_obj);
                msm_host->tx_gem_obj = NULL;
                mutex_unlock(&dev->struct_mutex);
        }
}

/*
 * prepare cmd buffer to be txed
 */
static int dsi_cmd_dma_add(struct drm_gem_object *tx_gem,
                        const struct mipi_dsi_msg *msg)
{
        struct mipi_dsi_packet packet;
        int len;
        int ret;
        u8 *data;

        ret = mipi_dsi_create_packet(&packet, msg);
        if (ret) {
                pr_err("%s: create packet failed, %d\n", __func__, ret);
                return ret;
        }
        len = (packet.size + 3) & (~0x3);

        if (len > tx_gem->size) {
                pr_err("%s: packet size is too big\n", __func__);
                return -EINVAL;
        }

        data = msm_gem_vaddr(tx_gem);

        if (IS_ERR(data)) {
                ret = PTR_ERR(data);
                pr_err("%s: get vaddr failed, %d\n", __func__, ret);
                return ret;
        }

        /* MSM specific command format in memory */
        data[0] = packet.header[1];
        data[1] = packet.header[2];
        data[2] = packet.header[0];
        data[3] = BIT(7); /* Last packet */
        if (mipi_dsi_packet_format_is_long(msg->type))
                data[3] |= BIT(6);
        if (msg->rx_buf && msg->rx_len)
                data[3] |= BIT(5);

        /* Long packet */
        if (packet.payload && packet.payload_length)
                memcpy(data + 4, packet.payload, packet.payload_length);

        /* Append 0xff to the end */
        if (packet.size < len)
                memset(data + packet.size, 0xff, len - packet.size);

        return len;
}

/*
 * dsi_short_read1_resp: 1 parameter
 */
static int dsi_short_read1_resp(u8 *buf, const struct mipi_dsi_msg *msg)
{
        u8 *data = msg->rx_buf;
        if (data && (msg->rx_len >= 1)) {
                *data = buf[1]; /* strip out dcs type */
                return 1;
        } else {
                pr_err("%s: read data does not match with rx_buf len %zu\n",
                        __func__, msg->rx_len);
                return -EINVAL;
        }
}

/*
 * dsi_short_read2_resp: 2 parameter
 */
static int dsi_short_read2_resp(u8 *buf, const struct mipi_dsi_msg *msg)
{
        u8 *data = msg->rx_buf;
        if (data && (msg->rx_len >= 2)) {
                data[0] = buf[1]; /* strip out dcs type */
                data[1] = buf[2];
                return 2;
        } else {
                pr_err("%s: read data does not match with rx_buf len %zu\n",
                        __func__, msg->rx_len);
                return -EINVAL;
        }
}

static int dsi_long_read_resp(u8 *buf, const struct mipi_dsi_msg *msg)
{
        /* strip out 4 byte dcs header */
        if (msg->rx_buf && msg->rx_len)
                memcpy(msg->rx_buf, buf + 4, msg->rx_len);

        return msg->rx_len;
}


static int dsi_cmd_dma_tx(struct msm_dsi_host *msm_host, int len)
{
        int ret;
        u32 iova;
        bool triggered;

        ret = msm_gem_get_iova(msm_host->tx_gem_obj, 0, &iova);
        if (ret) {
                pr_err("%s: failed to get iova: %d\n", __func__, ret);
                return ret;
        }

        reinit_completion(&msm_host->dma_comp);

        dsi_wait4video_eng_busy(msm_host);

        triggered = msm_dsi_manager_cmd_xfer_trigger(
                                                msm_host->id, iova, len);
        if (triggered) {
                ret = wait_for_completion_timeout(&msm_host->dma_comp,
                                        msecs_to_jiffies(200));
                DBG("ret=%d", ret);
                if (ret == 0)
                        ret = -ETIMEDOUT;
                else
                        ret = len;
        } else

                ret = len;

        return ret;
}

static int dsi_cmd_dma_rx(struct msm_dsi_host *msm_host,
                        u8 *buf, int rx_byte, int pkt_size)
{
        u32 *lp, *temp, data;
        int i, j = 0, cnt;
        u32 read_cnt;
        u8 reg[16];
        int repeated_bytes = 0;
        int buf_offset = buf - msm_host->rx_buf;

        lp = (u32 *)buf;
        temp = (u32 *)reg;
        cnt = (rx_byte + 3) >> 2;
        if (cnt > 4)
                cnt = 4; /* 4 x 32 bits registers only */

        if (rx_byte == 4)
                read_cnt = 4;
        else
                read_cnt = pkt_size + 6;

        /*
         * In case of multiple reads from the panel, after the first read, there
         * is possibility that there are some bytes in the payload repeating in
         * the RDBK_DATA registers. Since we read all the parameters from the
         * panel right from the first byte for every pass. We need to skip the
         * repeating bytes and then append the new parameters to the rx buffer.
         */
        if (read_cnt > 16) {
                int bytes_shifted;
                /* Any data more than 16 bytes will be shifted out.
                 * The temp read buffer should already contain these bytes.
                 * The remaining bytes in read buffer are the repeated bytes.
                 */
                bytes_shifted = read_cnt - 16;
                repeated_bytes = buf_offset - bytes_shifted;
        }

        for (i = cnt - 1; i >= 0; i--) {
                data = dsi_read(msm_host, REG_DSI_RDBK_DATA(i));
                *temp++ = ntohl(data); /* to host byte order */
                DBG("data = 0x%x and ntohl(data) = 0x%x", data, ntohl(data));
        }

        for (i = repeated_bytes; i < 16; i++)
                buf[j++] = reg[i];

        return j;
}

static int dsi_cmds2buf_tx(struct msm_dsi_host *msm_host,
                                const struct mipi_dsi_msg *msg)
{
        int len, ret;
        int bllp_len = msm_host->mode->hdisplay *
                        dsi_get_bpp(msm_host->format) / 8;

        len = dsi_cmd_dma_add(msm_host->tx_gem_obj, msg);
        if (!len) {
                pr_err("%s: failed to add cmd type = 0x%x\n",
                        __func__,  msg->type);
                return -EINVAL;
        }

        /* for video mode, do not send cmds more than
        * one pixel line, since it only transmit it
        * during BLLP.
        */
        /* TODO: if the command is sent in LP mode, the bit rate is only
         * half of esc clk rate. In this case, if the video is already
         * actively streaming, we need to check more carefully if the
         * command can be fit into one BLLP.
         */
        if ((msm_host->mode_flags & MIPI_DSI_MODE_VIDEO) && (len > bllp_len)) {
                pr_err("%s: cmd cannot fit into BLLP period, len=%d\n",
                        __func__, len);
                return -EINVAL;
        }

        ret = dsi_cmd_dma_tx(msm_host, len);
        if (ret < len) {
                pr_err("%s: cmd dma tx failed, type=0x%x, data0=0x%x, len=%d\n",
                        __func__, msg->type, (*(u8 *)(msg->tx_buf)), len);
                return -ECOMM;
        }

        return len;
}

static void dsi_sw_reset_restore(struct msm_dsi_host *msm_host)
{
        u32 data0, data1;

        data0 = dsi_read(msm_host, REG_DSI_CTRL);
        data1 = data0;
        data1 &= ~DSI_CTRL_ENABLE;
        dsi_write(msm_host, REG_DSI_CTRL, data1);
        /*
         * dsi controller need to be disabled before
         * clocks turned on
         */
        wmb();

        dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);
        wmb();  /* make sure clocks enabled */

        /* dsi controller can only be reset while clocks are running */
        dsi_write(msm_host, REG_DSI_RESET, 1);
        wmb();  /* make sure reset happen */
        dsi_write(msm_host, REG_DSI_RESET, 0);
        wmb();  /* controller out of reset */
        dsi_write(msm_host, REG_DSI_CTRL, data0);
        wmb();  /* make sure dsi controller enabled again */
}

static void dsi_err_worker(struct work_struct *work)
{
        struct msm_dsi_host *msm_host =
                container_of(work, struct msm_dsi_host, err_work);
        u32 status = msm_host->err_work_state;

        pr_err_ratelimited("%s: status=%x\n", __func__, status);
        if (status & DSI_ERR_STATE_MDP_FIFO_UNDERFLOW)
                dsi_sw_reset_restore(msm_host);

        /* It is safe to clear here because error irq is disabled. */
        msm_host->err_work_state = 0;

        /* enable dsi error interrupt */
        dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_ERROR, 1);
}

static void dsi_ack_err_status(struct msm_dsi_host *msm_host)
{
        u32 status;

        status = dsi_read(msm_host, REG_DSI_ACK_ERR_STATUS);

        if (status) {
                dsi_write(msm_host, REG_DSI_ACK_ERR_STATUS, status);
                /* Writing of an extra 0 needed to clear error bits */
                dsi_write(msm_host, REG_DSI_ACK_ERR_STATUS, 0);
                msm_host->err_work_state |= DSI_ERR_STATE_ACK;
        }
}

static void dsi_timeout_status(struct msm_dsi_host *msm_host)
{
        u32 status;

        status = dsi_read(msm_host, REG_DSI_TIMEOUT_STATUS);

        if (status) {
                dsi_write(msm_host, REG_DSI_TIMEOUT_STATUS, status);
                msm_host->err_work_state |= DSI_ERR_STATE_TIMEOUT;
        }
}

static void dsi_dln0_phy_err(struct msm_dsi_host *msm_host)
{
        u32 status;

        status = dsi_read(msm_host, REG_DSI_DLN0_PHY_ERR);

        if (status & (DSI_DLN0_PHY_ERR_DLN0_ERR_ESC |
                        DSI_DLN0_PHY_ERR_DLN0_ERR_SYNC_ESC |
                        DSI_DLN0_PHY_ERR_DLN0_ERR_CONTROL |
                        DSI_DLN0_PHY_ERR_DLN0_ERR_CONTENTION_LP0 |
                        DSI_DLN0_PHY_ERR_DLN0_ERR_CONTENTION_LP1)) {
                dsi_write(msm_host, REG_DSI_DLN0_PHY_ERR, status);
                msm_host->err_work_state |= DSI_ERR_STATE_DLN0_PHY;
        }
}

static void dsi_fifo_status(struct msm_dsi_host *msm_host)
{
        u32 status;

        status = dsi_read(msm_host, REG_DSI_FIFO_STATUS);

        /* fifo underflow, overflow */
        if (status) {
                dsi_write(msm_host, REG_DSI_FIFO_STATUS, status);
                msm_host->err_work_state |= DSI_ERR_STATE_FIFO;
                if (status & DSI_FIFO_STATUS_CMD_MDP_FIFO_UNDERFLOW)
                        msm_host->err_work_state |=
                                        DSI_ERR_STATE_MDP_FIFO_UNDERFLOW;
        }
}

static void dsi_status(struct msm_dsi_host *msm_host)
{
        u32 status;

        status = dsi_read(msm_host, REG_DSI_STATUS0);

        if (status & DSI_STATUS0_INTERLEAVE_OP_CONTENTION) {
                dsi_write(msm_host, REG_DSI_STATUS0, status);
                msm_host->err_work_state |=
                        DSI_ERR_STATE_INTERLEAVE_OP_CONTENTION;
        }
}

static void dsi_clk_status(struct msm_dsi_host *msm_host)
{
        u32 status;

        status = dsi_read(msm_host, REG_DSI_CLK_STATUS);

        if (status & DSI_CLK_STATUS_PLL_UNLOCKED) {
                dsi_write(msm_host, REG_DSI_CLK_STATUS, status);
                msm_host->err_work_state |= DSI_ERR_STATE_PLL_UNLOCKED;
        }
}

static void dsi_error(struct msm_dsi_host *msm_host)
{
        /* disable dsi error interrupt */
        dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_ERROR, 0);

        dsi_clk_status(msm_host);
        dsi_fifo_status(msm_host);
        dsi_ack_err_status(msm_host);
        dsi_timeout_status(msm_host);
        dsi_status(msm_host);
        dsi_dln0_phy_err(msm_host);

        queue_work(msm_host->workqueue, &msm_host->err_work);
}

static irqreturn_t dsi_host_irq(int irq, void *ptr)
{
        struct msm_dsi_host *msm_host = ptr;
        u32 isr;
        unsigned long flags;

        if (!msm_host->ctrl_base)
                return IRQ_HANDLED;

        spin_lock_irqsave(&msm_host->intr_lock, flags);
        isr = dsi_read(msm_host, REG_DSI_INTR_CTRL);
        dsi_write(msm_host, REG_DSI_INTR_CTRL, isr);
        spin_unlock_irqrestore(&msm_host->intr_lock, flags);

        DBG("isr=0x%x, id=%d", isr, msm_host->id);

        if (isr & DSI_IRQ_ERROR)
                dsi_error(msm_host);

        if (isr & DSI_IRQ_VIDEO_DONE)
                complete(&msm_host->video_comp);

        if (isr & DSI_IRQ_CMD_DMA_DONE)
                complete(&msm_host->dma_comp);

        return IRQ_HANDLED;
}

static int dsi_host_init_panel_gpios(struct msm_dsi_host *msm_host,
                        struct device *panel_device)
{
        msm_host->disp_en_gpio = devm_gpiod_get_optional(panel_device,
                                                         "disp-enable",
                                                         GPIOD_OUT_LOW);
        if (IS_ERR(msm_host->disp_en_gpio)) {
                DBG("cannot get disp-enable-gpios %ld",
                                PTR_ERR(msm_host->disp_en_gpio));
                return PTR_ERR(msm_host->disp_en_gpio);
        }

        msm_host->te_gpio = devm_gpiod_get_optional(panel_device, "disp-te",
                                                                GPIOD_IN);
        if (IS_ERR(msm_host->te_gpio)) {
                DBG("cannot get disp-te-gpios %ld", PTR_ERR(msm_host->te_gpio));
                return PTR_ERR(msm_host->te_gpio);
        }

        return 0;
}

static int dsi_host_attach(struct mipi_dsi_host *host,
                                        struct mipi_dsi_device *dsi)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
        int ret;

        msm_host->channel = dsi->channel;
        msm_host->lanes = dsi->lanes;
        msm_host->format = dsi->format;
        msm_host->mode_flags = dsi->mode_flags;

        WARN_ON(dsi->dev.of_node != msm_host->device_node);

        /* Some gpios defined in panel DT need to be controlled by host */
        ret = dsi_host_init_panel_gpios(msm_host, &dsi->dev);
        if (ret)
                return ret;

        DBG("id=%d", msm_host->id);
        if (msm_host->dev)
                drm_helper_hpd_irq_event(msm_host->dev);

        return 0;
}

static int dsi_host_detach(struct mipi_dsi_host *host,
                                        struct mipi_dsi_device *dsi)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        msm_host->device_node = NULL;

        DBG("id=%d", msm_host->id);
        if (msm_host->dev)
                drm_helper_hpd_irq_event(msm_host->dev);

        return 0;
}

static ssize_t dsi_host_transfer(struct mipi_dsi_host *host,
                                        const struct mipi_dsi_msg *msg)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
        int ret;

        if (!msg || !msm_host->power_on)
                return -EINVAL;

        mutex_lock(&msm_host->cmd_mutex);
        ret = msm_dsi_manager_cmd_xfer(msm_host->id, msg);
        mutex_unlock(&msm_host->cmd_mutex);

        return ret;
}

static struct mipi_dsi_host_ops dsi_host_ops = {
        .attach = dsi_host_attach,
        .detach = dsi_host_detach,
        .transfer = dsi_host_transfer,
};

static int dsi_host_parse_dt(struct msm_dsi_host *msm_host)
{
        struct device *dev = &msm_host->pdev->dev;
        struct device_node *np = dev->of_node;
        struct device_node *endpoint, *device_node;
        int ret;

        ret = of_property_read_u32(np, "qcom,dsi-host-index", &msm_host->id);
        if (ret) {
                dev_err(dev, "%s: host index not specified, ret=%d\n",
                        __func__, ret);
                return ret;
        }

        /*
         * Get the first endpoint node. In our case, dsi has one output port
         * to which the panel is connected. Don't return an error if a port
         * isn't defined. It's possible that there is nothing connected to
         * the dsi output.
         */
        endpoint = of_graph_get_next_endpoint(np, NULL);
        if (!endpoint) {
                dev_dbg(dev, "%s: no endpoint\n", __func__);
                return 0;
        }

        /* Get panel node from the output port's endpoint data */
        device_node = of_graph_get_remote_port_parent(endpoint);
        if (!device_node) {
                dev_err(dev, "%s: no valid device\n", __func__);
                of_node_put(endpoint);
                return -ENODEV;
        }

        of_node_put(endpoint);
        of_node_put(device_node);

        msm_host->device_node = device_node;

        return 0;
}

int msm_dsi_host_init(struct msm_dsi *msm_dsi)
{
        struct msm_dsi_host *msm_host = NULL;
        struct platform_device *pdev = msm_dsi->pdev;
        int ret;

        msm_host = devm_kzalloc(&pdev->dev, sizeof(*msm_host), GFP_KERNEL);
        if (!msm_host) {
                pr_err("%s: FAILED: cannot alloc dsi host\n",
                       __func__);
                ret = -ENOMEM;
                goto fail;
        }

        msm_host->pdev = pdev;

        ret = dsi_host_parse_dt(msm_host);
        if (ret) {
                pr_err("%s: failed to parse dt\n", __func__);
                goto fail;
        }

        ret = dsi_clk_init(msm_host);
        if (ret) {
                pr_err("%s: unable to initialize dsi clks\n", __func__);
                goto fail;
        }

        msm_host->ctrl_base = msm_ioremap(pdev, "dsi_ctrl", "DSI CTRL");
        if (IS_ERR(msm_host->ctrl_base)) {
                pr_err("%s: unable to map Dsi ctrl base\n", __func__);
                ret = PTR_ERR(msm_host->ctrl_base);
                goto fail;
        }

        msm_host->cfg_hnd = dsi_get_config(msm_host);
        if (!msm_host->cfg_hnd) {
                ret = -EINVAL;
                pr_err("%s: get config failed\n", __func__);
                goto fail;
        }

        /* fixup base address by io offset */
        msm_host->ctrl_base += msm_host->cfg_hnd->cfg->io_offset;

        ret = dsi_regulator_init(msm_host);
        if (ret) {
                pr_err("%s: regulator init failed\n", __func__);
                goto fail;
        }

        msm_host->rx_buf = devm_kzalloc(&pdev->dev, SZ_4K, GFP_KERNEL);
        if (!msm_host->rx_buf) {
                pr_err("%s: alloc rx temp buf failed\n", __func__);
                goto fail;
        }

        init_completion(&msm_host->dma_comp);
        init_completion(&msm_host->video_comp);
        mutex_init(&msm_host->dev_mutex);
        mutex_init(&msm_host->cmd_mutex);
        mutex_init(&msm_host->clk_mutex);
        spin_lock_init(&msm_host->intr_lock);

        /* setup workqueue */
        msm_host->workqueue = alloc_ordered_workqueue("dsi_drm_work", 0);
        INIT_WORK(&msm_host->err_work, dsi_err_worker);

        msm_dsi->host = &msm_host->base;
        msm_dsi->id = msm_host->id;

        DBG("Dsi Host %d initialized", msm_host->id);
        return 0;

fail:
        return ret;
}

void msm_dsi_host_destroy(struct mipi_dsi_host *host)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        DBG("");
        dsi_tx_buf_free(msm_host);
        if (msm_host->workqueue) {
                flush_workqueue(msm_host->workqueue);
                destroy_workqueue(msm_host->workqueue);
                msm_host->workqueue = NULL;
        }

        mutex_destroy(&msm_host->clk_mutex);
        mutex_destroy(&msm_host->cmd_mutex);
        mutex_destroy(&msm_host->dev_mutex);
}

int msm_dsi_host_modeset_init(struct mipi_dsi_host *host,
                                        struct drm_device *dev)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
        struct platform_device *pdev = msm_host->pdev;
        int ret;

        msm_host->irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
        if (msm_host->irq < 0) {
                ret = msm_host->irq;
                dev_err(dev->dev, "failed to get irq: %d\n", ret);
                return ret;
        }

        ret = devm_request_irq(&pdev->dev, msm_host->irq,
                        dsi_host_irq, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
                        "dsi_isr", msm_host);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to request IRQ%u: %d\n",
                                msm_host->irq, ret);
                return ret;
        }

        msm_host->dev = dev;
        ret = dsi_tx_buf_alloc(msm_host, SZ_4K);
        if (ret) {
                pr_err("%s: alloc tx gem obj failed, %d\n", __func__, ret);
                return ret;
        }

        return 0;
}

int msm_dsi_host_register(struct mipi_dsi_host *host, bool check_defer)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
        int ret;

        /* Register mipi dsi host */
        if (!msm_host->registered) {
                host->dev = &msm_host->pdev->dev;
                host->ops = &dsi_host_ops;
                ret = mipi_dsi_host_register(host);
                if (ret)
                        return ret;

                msm_host->registered = true;

                /* If the panel driver has not been probed after host register,
                 * we should defer the host's probe.
                 * It makes sure panel is connected when fbcon detects
                 * connector status and gets the proper display mode to
                 * create framebuffer.
                 * Don't try to defer if there is nothing connected to the dsi
                 * output
                 */
                if (check_defer && msm_host->device_node) {
                        if (!of_drm_find_panel(msm_host->device_node))
                                if (!of_drm_find_bridge(msm_host->device_node))
                                        return -EPROBE_DEFER;
                }
        }

        return 0;
}

void msm_dsi_host_unregister(struct mipi_dsi_host *host)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        if (msm_host->registered) {
                mipi_dsi_host_unregister(host);
                host->dev = NULL;
                host->ops = NULL;
                msm_host->registered = false;
        }
}

int msm_dsi_host_xfer_prepare(struct mipi_dsi_host *host,
                                const struct mipi_dsi_msg *msg)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        /* TODO: make sure dsi_cmd_mdp is idle.
         * Since DSI6G v1.2.0, we can set DSI_TRIG_CTRL.BLOCK_DMA_WITHIN_FRAME
         * to ask H/W to wait until cmd mdp is idle. S/W wait is not needed.
         * How to handle the old versions? Wait for mdp cmd done?
         */

        /*
         * mdss interrupt is generated in mdp core clock domain
         * mdp clock need to be enabled to receive dsi interrupt
         */
        dsi_clk_ctrl(msm_host, 1);

        /* TODO: vote for bus bandwidth */

        if (!(msg->flags & MIPI_DSI_MSG_USE_LPM))
                dsi_set_tx_power_mode(0, msm_host);

        msm_host->dma_cmd_ctrl_restore = dsi_read(msm_host, REG_DSI_CTRL);
        dsi_write(msm_host, REG_DSI_CTRL,
                msm_host->dma_cmd_ctrl_restore |
                DSI_CTRL_CMD_MODE_EN |
                DSI_CTRL_ENABLE);
        dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_CMD_DMA_DONE, 1);

        return 0;
}

void msm_dsi_host_xfer_restore(struct mipi_dsi_host *host,
                                const struct mipi_dsi_msg *msg)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        dsi_intr_ctrl(msm_host, DSI_IRQ_MASK_CMD_DMA_DONE, 0);
        dsi_write(msm_host, REG_DSI_CTRL, msm_host->dma_cmd_ctrl_restore);

        if (!(msg->flags & MIPI_DSI_MSG_USE_LPM))
                dsi_set_tx_power_mode(1, msm_host);

        /* TODO: unvote for bus bandwidth */

        dsi_clk_ctrl(msm_host, 0);
}

int msm_dsi_host_cmd_tx(struct mipi_dsi_host *host,
                                const struct mipi_dsi_msg *msg)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        return dsi_cmds2buf_tx(msm_host, msg);
}

int msm_dsi_host_cmd_rx(struct mipi_dsi_host *host,
                                const struct mipi_dsi_msg *msg)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
        const struct msm_dsi_cfg_handler *cfg_hnd = msm_host->cfg_hnd;
        int data_byte, rx_byte, dlen, end;
        int short_response, diff, pkt_size, ret = 0;
        char cmd;
        int rlen = msg->rx_len;
        u8 *buf;

        if (rlen <= 2) {
                short_response = 1;
                pkt_size = rlen;
                rx_byte = 4;
        } else {
                short_response = 0;
                data_byte = 10; /* first read */
                if (rlen < data_byte)
                        pkt_size = rlen;
                else
                        pkt_size = data_byte;
                rx_byte = data_byte + 6; /* 4 header + 2 crc */
        }

        buf = msm_host->rx_buf;
        end = 0;
        while (!end) {
                u8 tx[2] = {pkt_size & 0xff, pkt_size >> 8};
                struct mipi_dsi_msg max_pkt_size_msg = {
                        .channel = msg->channel,
                        .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
                        .tx_len = 2,
                        .tx_buf = tx,
                };

                DBG("rlen=%d pkt_size=%d rx_byte=%d",
                        rlen, pkt_size, rx_byte);

                ret = dsi_cmds2buf_tx(msm_host, &max_pkt_size_msg);
                if (ret < 2) {
                        pr_err("%s: Set max pkt size failed, %d\n",
                                __func__, ret);
                        return -EINVAL;
                }

                if ((cfg_hnd->major == MSM_DSI_VER_MAJOR_6G) &&
                        (cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V1_1)) {
                        /* Clear the RDBK_DATA registers */
                        dsi_write(msm_host, REG_DSI_RDBK_DATA_CTRL,
                                        DSI_RDBK_DATA_CTRL_CLR);
                        wmb(); /* make sure the RDBK registers are cleared */
                        dsi_write(msm_host, REG_DSI_RDBK_DATA_CTRL, 0);
                        wmb(); /* release cleared status before transfer */
                }

                ret = dsi_cmds2buf_tx(msm_host, msg);
                if (ret < msg->tx_len) {
                        pr_err("%s: Read cmd Tx failed, %d\n", __func__, ret);
                        return ret;
                }

                /*
                 * once cmd_dma_done interrupt received,
                 * return data from client is ready and stored
                 * at RDBK_DATA register already
                 * since rx fifo is 16 bytes, dcs header is kept at first loop,
                 * after that dcs header lost during shift into registers
                 */
                dlen = dsi_cmd_dma_rx(msm_host, buf, rx_byte, pkt_size);

                if (dlen <= 0)
                        return 0;

                if (short_response)
                        break;

                if (rlen <= data_byte) {
                        diff = data_byte - rlen;
                        end = 1;
                } else {
                        diff = 0;
                        rlen -= data_byte;
                }

                if (!end) {
                        dlen -= 2; /* 2 crc */
                        dlen -= diff;
                        buf += dlen;    /* next start position */
                        data_byte = 14; /* NOT first read */
                        if (rlen < data_byte)
                                pkt_size += rlen;
                        else
                                pkt_size += data_byte;
                        DBG("buf=%p dlen=%d diff=%d", buf, dlen, diff);
                }
        }

        /*
         * For single Long read, if the requested rlen < 10,
         * we need to shift the start position of rx
         * data buffer to skip the bytes which are not
         * updated.
         */
        if (pkt_size < 10 && !short_response)
                buf = msm_host->rx_buf + (10 - rlen);
        else
                buf = msm_host->rx_buf;

        cmd = buf[0];
        switch (cmd) {
        case MIPI_DSI_RX_ACKNOWLEDGE_AND_ERROR_REPORT:
                pr_err("%s: rx ACK_ERR_PACLAGE\n", __func__);
                ret = 0;
                break;
        case MIPI_DSI_RX_GENERIC_SHORT_READ_RESPONSE_1BYTE:
        case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_1BYTE:
                ret = dsi_short_read1_resp(buf, msg);
                break;
        case MIPI_DSI_RX_GENERIC_SHORT_READ_RESPONSE_2BYTE:
        case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_2BYTE:
                ret = dsi_short_read2_resp(buf, msg);
                break;
        case MIPI_DSI_RX_GENERIC_LONG_READ_RESPONSE:
        case MIPI_DSI_RX_DCS_LONG_READ_RESPONSE:
                ret = dsi_long_read_resp(buf, msg);
                break;
        default:
                pr_warn("%s:Invalid response cmd\n", __func__);
                ret = 0;
        }

        return ret;
}

void msm_dsi_host_cmd_xfer_commit(struct mipi_dsi_host *host, u32 iova, u32 len)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        dsi_write(msm_host, REG_DSI_DMA_BASE, iova);
        dsi_write(msm_host, REG_DSI_DMA_LEN, len);
        dsi_write(msm_host, REG_DSI_TRIG_DMA, 1);

        /* Make sure trigger happens */
        wmb();
}

int msm_dsi_host_set_src_pll(struct mipi_dsi_host *host,
        struct msm_dsi_pll *src_pll)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
        struct clk *byte_clk_provider, *pixel_clk_provider;
        int ret;

        ret = msm_dsi_pll_get_clk_provider(src_pll,
                                &byte_clk_provider, &pixel_clk_provider);
        if (ret) {
                pr_info("%s: can't get provider from pll, don't set parent\n",
                        __func__);
                return 0;
        }

        ret = clk_set_parent(msm_host->byte_clk_src, byte_clk_provider);
        if (ret) {
                pr_err("%s: can't set parent to byte_clk_src. ret=%d\n",
                        __func__, ret);
                goto exit;
        }

        ret = clk_set_parent(msm_host->pixel_clk_src, pixel_clk_provider);
        if (ret) {
                pr_err("%s: can't set parent to pixel_clk_src. ret=%d\n",
                        __func__, ret);
                goto exit;
        }

exit:
        return ret;
}

int msm_dsi_host_enable(struct mipi_dsi_host *host)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        dsi_op_mode_config(msm_host,
                !!(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO), true);

        /* TODO: clock should be turned off for command mode,
         * and only turned on before MDP START.
         * This part of code should be enabled once mdp driver support it.
         */
        /* if (msm_panel->mode == MSM_DSI_CMD_MODE)
                dsi_clk_ctrl(msm_host, 0); */

        return 0;
}

int msm_dsi_host_disable(struct mipi_dsi_host *host)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        dsi_op_mode_config(msm_host,
                !!(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO), false);

        /* Since we have disabled INTF, the video engine won't stop so that
         * the cmd engine will be blocked.
         * Reset to disable video engine so that we can send off cmd.
         */
        dsi_sw_reset(msm_host);

        return 0;
}

int msm_dsi_host_power_on(struct mipi_dsi_host *host)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
        u32 clk_pre = 0, clk_post = 0;
        int ret = 0;

        mutex_lock(&msm_host->dev_mutex);
        if (msm_host->power_on) {
                DBG("dsi host already on");
                goto unlock_ret;
        }

        ret = dsi_calc_clk_rate(msm_host);
        if (ret) {
                pr_err("%s: unable to calc clk rate, %d\n", __func__, ret);
                goto unlock_ret;
        }

        ret = dsi_host_regulator_enable(msm_host);
        if (ret) {
                pr_err("%s:Failed to enable vregs.ret=%d\n",
                        __func__, ret);
                goto unlock_ret;
        }

        ret = dsi_bus_clk_enable(msm_host);
        if (ret) {
                pr_err("%s: failed to enable bus clocks, %d\n", __func__, ret);
                goto fail_disable_reg;
        }

        dsi_phy_sw_reset(msm_host);
        ret = msm_dsi_manager_phy_enable(msm_host->id,
                                        msm_host->byte_clk_rate * 8,
                                        clk_get_rate(msm_host->esc_clk),
                                        &clk_pre, &clk_post);
        dsi_bus_clk_disable(msm_host);
        if (ret) {
                pr_err("%s: failed to enable phy, %d\n", __func__, ret);
                goto fail_disable_reg;
        }

        ret = dsi_clk_ctrl(msm_host, 1);
        if (ret) {
                pr_err("%s: failed to enable clocks. ret=%d\n", __func__, ret);
                goto fail_disable_reg;
        }

        ret = pinctrl_pm_select_default_state(&msm_host->pdev->dev);
        if (ret) {
                pr_err("%s: failed to set pinctrl default state, %d\n",
                        __func__, ret);
                goto fail_disable_clk;
        }

        dsi_timing_setup(msm_host);
        dsi_sw_reset(msm_host);
        dsi_ctrl_config(msm_host, true, clk_pre, clk_post);

        if (msm_host->disp_en_gpio)
                gpiod_set_value(msm_host->disp_en_gpio, 1);

        msm_host->power_on = true;
        mutex_unlock(&msm_host->dev_mutex);

        return 0;

fail_disable_clk:
        dsi_clk_ctrl(msm_host, 0);
fail_disable_reg:
        dsi_host_regulator_disable(msm_host);
unlock_ret:
        mutex_unlock(&msm_host->dev_mutex);
        return ret;
}

int msm_dsi_host_power_off(struct mipi_dsi_host *host)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        mutex_lock(&msm_host->dev_mutex);
        if (!msm_host->power_on) {
                DBG("dsi host already off");
                goto unlock_ret;
        }

        dsi_ctrl_config(msm_host, false, 0, 0);

        if (msm_host->disp_en_gpio)
                gpiod_set_value(msm_host->disp_en_gpio, 0);

        pinctrl_pm_select_sleep_state(&msm_host->pdev->dev);

        msm_dsi_manager_phy_disable(msm_host->id);

        dsi_clk_ctrl(msm_host, 0);

        dsi_host_regulator_disable(msm_host);

        DBG("-");

        msm_host->power_on = false;

unlock_ret:
        mutex_unlock(&msm_host->dev_mutex);
        return 0;
}

int msm_dsi_host_set_display_mode(struct mipi_dsi_host *host,
                                        struct drm_display_mode *mode)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        if (msm_host->mode) {
                drm_mode_destroy(msm_host->dev, msm_host->mode);
                msm_host->mode = NULL;
        }

        msm_host->mode = drm_mode_duplicate(msm_host->dev, mode);
        if (IS_ERR(msm_host->mode)) {
                pr_err("%s: cannot duplicate mode\n", __func__);
                return PTR_ERR(msm_host->mode);
        }

        return 0;
}

struct drm_panel *msm_dsi_host_get_panel(struct mipi_dsi_host *host,
                                unsigned long *panel_flags)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
        struct drm_panel *panel;

        panel = of_drm_find_panel(msm_host->device_node);
        if (panel_flags)
                        *panel_flags = msm_host->mode_flags;

        return panel;
}

struct drm_bridge *msm_dsi_host_get_bridge(struct mipi_dsi_host *host)
{
        struct msm_dsi_host *msm_host = to_msm_dsi_host(host);

        return of_drm_find_bridge(msm_host->device_node);
}