/*
 * Copyright (C) STMicroelectronics SA 2014
 * Author: Vincent Abriou <vincent.abriou@st.com> for STMicroelectronics.
 * License terms:  GNU General Public License (GPL), version 2
 */

#include <linux/clk.h>
#include <linux/component.h>
#include <linux/hdmi.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/reset.h>

#include <drm/drmP.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_edid.h>

#include "sti_hdmi.h"
#include "sti_hdmi_tx3g4c28phy.h"
#include "sti_hdmi_tx3g0c55phy.h"
#include "sti_vtg.h"

#define HDMI_CFG                        0x0000
#define HDMI_INT_EN                     0x0004
#define HDMI_INT_STA                    0x0008
#define HDMI_INT_CLR                    0x000C
#define HDMI_STA                        0x0010
#define HDMI_ACTIVE_VID_XMIN            0x0100
#define HDMI_ACTIVE_VID_XMAX            0x0104
#define HDMI_ACTIVE_VID_YMIN            0x0108
#define HDMI_ACTIVE_VID_YMAX            0x010C
#define HDMI_DFLT_CHL0_DAT              0x0110
#define HDMI_DFLT_CHL1_DAT              0x0114
#define HDMI_DFLT_CHL2_DAT              0x0118
#define HDMI_SW_DI_1_HEAD_WORD          0x0210
#define HDMI_SW_DI_1_PKT_WORD0          0x0214
#define HDMI_SW_DI_1_PKT_WORD1          0x0218
#define HDMI_SW_DI_1_PKT_WORD2          0x021C
#define HDMI_SW_DI_1_PKT_WORD3          0x0220
#define HDMI_SW_DI_1_PKT_WORD4          0x0224
#define HDMI_SW_DI_1_PKT_WORD5          0x0228
#define HDMI_SW_DI_1_PKT_WORD6          0x022C
#define HDMI_SW_DI_CFG                  0x0230
#define HDMI_SW_DI_2_HEAD_WORD          0x0600
#define HDMI_SW_DI_2_PKT_WORD0          0x0604
#define HDMI_SW_DI_2_PKT_WORD1          0x0608
#define HDMI_SW_DI_2_PKT_WORD2          0x060C
#define HDMI_SW_DI_2_PKT_WORD3          0x0610
#define HDMI_SW_DI_2_PKT_WORD4          0x0614
#define HDMI_SW_DI_2_PKT_WORD5          0x0618
#define HDMI_SW_DI_2_PKT_WORD6          0x061C

#define HDMI_IFRAME_SLOT_AVI            1
#define HDMI_IFRAME_SLOT_AUDIO          2

#define  XCAT(prefix, x, suffix)        prefix ## x ## suffix
#define  HDMI_SW_DI_N_HEAD_WORD(x)      XCAT(HDMI_SW_DI_, x, _HEAD_WORD)
#define  HDMI_SW_DI_N_PKT_WORD0(x)      XCAT(HDMI_SW_DI_, x, _PKT_WORD0)
#define  HDMI_SW_DI_N_PKT_WORD1(x)      XCAT(HDMI_SW_DI_, x, _PKT_WORD1)
#define  HDMI_SW_DI_N_PKT_WORD2(x)      XCAT(HDMI_SW_DI_, x, _PKT_WORD2)
#define  HDMI_SW_DI_N_PKT_WORD3(x)      XCAT(HDMI_SW_DI_, x, _PKT_WORD3)
#define  HDMI_SW_DI_N_PKT_WORD4(x)      XCAT(HDMI_SW_DI_, x, _PKT_WORD4)
#define  HDMI_SW_DI_N_PKT_WORD5(x)      XCAT(HDMI_SW_DI_, x, _PKT_WORD5)
#define  HDMI_SW_DI_N_PKT_WORD6(x)      XCAT(HDMI_SW_DI_, x, _PKT_WORD6)

#define HDMI_IFRAME_DISABLED            0x0
#define HDMI_IFRAME_SINGLE_SHOT         0x1
#define HDMI_IFRAME_FIELD               0x2
#define HDMI_IFRAME_FRAME               0x3
#define HDMI_IFRAME_MASK                0x3
#define HDMI_IFRAME_CFG_DI_N(x, n)       ((x) << ((n-1)*4)) /* n from 1 to 6 */

#define HDMI_CFG_DEVICE_EN              BIT(0)
#define HDMI_CFG_HDMI_NOT_DVI           BIT(1)
#define HDMI_CFG_HDCP_EN                BIT(2)
#define HDMI_CFG_ESS_NOT_OESS           BIT(3)
#define HDMI_CFG_H_SYNC_POL_NEG         BIT(4)
#define HDMI_CFG_SINK_TERM_DET_EN       BIT(5)
#define HDMI_CFG_V_SYNC_POL_NEG         BIT(6)
#define HDMI_CFG_422_EN                 BIT(8)
#define HDMI_CFG_FIFO_OVERRUN_CLR       BIT(12)
#define HDMI_CFG_FIFO_UNDERRUN_CLR      BIT(13)
#define HDMI_CFG_SW_RST_EN              BIT(31)

#define HDMI_INT_GLOBAL                 BIT(0)
#define HDMI_INT_SW_RST                 BIT(1)
#define HDMI_INT_PIX_CAP                BIT(3)
#define HDMI_INT_HOT_PLUG               BIT(4)
#define HDMI_INT_DLL_LCK                BIT(5)
#define HDMI_INT_NEW_FRAME              BIT(6)
#define HDMI_INT_GENCTRL_PKT            BIT(7)
#define HDMI_INT_SINK_TERM_PRESENT      BIT(11)

#define HDMI_DEFAULT_INT (HDMI_INT_SINK_TERM_PRESENT \
                        | HDMI_INT_DLL_LCK \
                        | HDMI_INT_HOT_PLUG \
                        | HDMI_INT_GLOBAL)

#define HDMI_WORKING_INT (HDMI_INT_SINK_TERM_PRESENT \
                        | HDMI_INT_GENCTRL_PKT \
                        | HDMI_INT_NEW_FRAME \
                        | HDMI_INT_DLL_LCK \
                        | HDMI_INT_HOT_PLUG \
                        | HDMI_INT_PIX_CAP \
                        | HDMI_INT_SW_RST \
                        | HDMI_INT_GLOBAL)

#define HDMI_STA_SW_RST                 BIT(1)

#define HDMI_INFOFRAME_HEADER_TYPE(x)    (((x) & 0xff) <<  0)
#define HDMI_INFOFRAME_HEADER_VERSION(x) (((x) & 0xff) <<  8)
#define HDMI_INFOFRAME_HEADER_LEN(x)     (((x) & 0x0f) << 16)

struct sti_hdmi_connector {
        struct drm_connector drm_connector;
        struct drm_encoder *encoder;
        struct sti_hdmi *hdmi;
};

#define to_sti_hdmi_connector(x) \
        container_of(x, struct sti_hdmi_connector, drm_connector)

u32 hdmi_read(struct sti_hdmi *hdmi, int offset)
{
        return readl(hdmi->regs + offset);
}

void hdmi_write(struct sti_hdmi *hdmi, u32 val, int offset)
{
        writel(val, hdmi->regs + offset);
}

/**
 * HDMI interrupt handler threaded
 *
 * @irq: irq number
 * @arg: connector structure
 */
static irqreturn_t hdmi_irq_thread(int irq, void *arg)
{
        struct sti_hdmi *hdmi = arg;

        /* Hot plug/unplug IRQ */
        if (hdmi->irq_status & HDMI_INT_HOT_PLUG) {
                hdmi->hpd = readl(hdmi->regs + HDMI_STA) & HDMI_STA_HOT_PLUG;
                if (hdmi->drm_dev)
                        drm_helper_hpd_irq_event(hdmi->drm_dev);
        }

        /* Sw reset and PLL lock are exclusive so we can use the same
         * event to signal them
         */
        if (hdmi->irq_status & (HDMI_INT_SW_RST | HDMI_INT_DLL_LCK)) {
                hdmi->event_received = true;
                wake_up_interruptible(&hdmi->wait_event);
        }

        return IRQ_HANDLED;
}

/**
 * HDMI interrupt handler
 *
 * @irq: irq number
 * @arg: connector structure
 */
static irqreturn_t hdmi_irq(int irq, void *arg)
{
        struct sti_hdmi *hdmi = arg;

        /* read interrupt status */
        hdmi->irq_status = hdmi_read(hdmi, HDMI_INT_STA);

        /* clear interrupt status */
        hdmi_write(hdmi, hdmi->irq_status, HDMI_INT_CLR);

        /* force sync bus write */
        hdmi_read(hdmi, HDMI_INT_STA);

        return IRQ_WAKE_THREAD;
}

/**
 * Set hdmi active area depending on the drm display mode selected
 *
 * @hdmi: pointer on the hdmi internal structure
 */
static void hdmi_active_area(struct sti_hdmi *hdmi)
{
        u32 xmin, xmax;
        u32 ymin, ymax;

        xmin = sti_vtg_get_pixel_number(hdmi->mode, 0);
        xmax = sti_vtg_get_pixel_number(hdmi->mode, hdmi->mode.hdisplay - 1);
        ymin = sti_vtg_get_line_number(hdmi->mode, 0);
        ymax = sti_vtg_get_line_number(hdmi->mode, hdmi->mode.vdisplay - 1);

        hdmi_write(hdmi, xmin, HDMI_ACTIVE_VID_XMIN);
        hdmi_write(hdmi, xmax, HDMI_ACTIVE_VID_XMAX);
        hdmi_write(hdmi, ymin, HDMI_ACTIVE_VID_YMIN);
        hdmi_write(hdmi, ymax, HDMI_ACTIVE_VID_YMAX);
}

/**
 * Overall hdmi configuration
 *
 * @hdmi: pointer on the hdmi internal structure
 */
static void hdmi_config(struct sti_hdmi *hdmi)
{
        u32 conf;

        DRM_DEBUG_DRIVER("\n");

        /* Clear overrun and underrun fifo */
        conf = HDMI_CFG_FIFO_OVERRUN_CLR | HDMI_CFG_FIFO_UNDERRUN_CLR;

        /* Enable HDMI mode not DVI */
        conf |= HDMI_CFG_HDMI_NOT_DVI | HDMI_CFG_ESS_NOT_OESS;

        /* Enable sink term detection */
        conf |= HDMI_CFG_SINK_TERM_DET_EN;

        /* Set Hsync polarity */
        if (hdmi->mode.flags & DRM_MODE_FLAG_NHSYNC) {
                DRM_DEBUG_DRIVER("H Sync Negative\n");
                conf |= HDMI_CFG_H_SYNC_POL_NEG;
        }

        /* Set Vsync polarity */
        if (hdmi->mode.flags & DRM_MODE_FLAG_NVSYNC) {
                DRM_DEBUG_DRIVER("V Sync Negative\n");
                conf |= HDMI_CFG_V_SYNC_POL_NEG;
        }

        /* Enable HDMI */
        conf |= HDMI_CFG_DEVICE_EN;

        hdmi_write(hdmi, conf, HDMI_CFG);
}

/**
 * Helper to concatenate infoframe in 32 bits word
 *
 * @ptr: pointer on the hdmi internal structure
 * @data: infoframe to write
 * @size: size to write
 */
static inline unsigned int hdmi_infoframe_subpack(const u8 *ptr, size_t size)
{
        unsigned long value = 0;
        size_t i;

        for (i = size; i > 0; i--)
                value = (value << 8) | ptr[i - 1];

        return value;
}

/**
 * Helper to write info frame
 *
 * @hdmi: pointer on the hdmi internal structure
 * @data: infoframe to write
 * @size: size to write
 */
static void hdmi_infoframe_write_infopack(struct sti_hdmi *hdmi, const u8 *data)
{
        const u8 *ptr = data;
        u32 val, slot, mode, i;
        u32 head_offset, pack_offset;
        size_t size;

        switch (*ptr) {
        case HDMI_INFOFRAME_TYPE_AVI:
                slot = HDMI_IFRAME_SLOT_AVI;
                mode = HDMI_IFRAME_FIELD;
                head_offset = HDMI_SW_DI_N_HEAD_WORD(HDMI_IFRAME_SLOT_AVI);
                pack_offset = HDMI_SW_DI_N_PKT_WORD0(HDMI_IFRAME_SLOT_AVI);
                size = HDMI_AVI_INFOFRAME_SIZE;
                break;

        case HDMI_INFOFRAME_TYPE_AUDIO:
                slot = HDMI_IFRAME_SLOT_AUDIO;
                mode = HDMI_IFRAME_FRAME;
                head_offset = HDMI_SW_DI_N_HEAD_WORD(HDMI_IFRAME_SLOT_AUDIO);
                pack_offset = HDMI_SW_DI_N_PKT_WORD0(HDMI_IFRAME_SLOT_AUDIO);
                size = HDMI_AUDIO_INFOFRAME_SIZE;
                break;

        default:
                DRM_ERROR("unsupported infoframe type: %#x\n", *ptr);
                return;
        }

        /* Disable transmission slot for updated infoframe */
        val = hdmi_read(hdmi, HDMI_SW_DI_CFG);
        val &= ~HDMI_IFRAME_CFG_DI_N(HDMI_IFRAME_MASK, slot);
        hdmi_write(hdmi, val, HDMI_SW_DI_CFG);

        val = HDMI_INFOFRAME_HEADER_TYPE(*ptr++);
        val |= HDMI_INFOFRAME_HEADER_VERSION(*ptr++);
        val |= HDMI_INFOFRAME_HEADER_LEN(*ptr++);
        writel(val, hdmi->regs + head_offset);

        /*
         * Each subpack contains 4 bytes
         * The First Bytes of the first subpacket must contain the checksum
         * Packet size in increase by one.
         */
        for (i = 0; i < size; i += sizeof(u32)) {
                size_t num;

                num = min_t(size_t, size - i, sizeof(u32));
                val = hdmi_infoframe_subpack(ptr, num);
                ptr += sizeof(u32);
                writel(val, hdmi->regs + pack_offset + i);
        }

        /* Enable transmission slot for updated infoframe */
        val = hdmi_read(hdmi, HDMI_SW_DI_CFG);
        val |= HDMI_IFRAME_CFG_DI_N(HDMI_IFRAME_FIELD, slot);
        hdmi_write(hdmi, val, HDMI_SW_DI_CFG);
}

/**
 * Prepare and configure the AVI infoframe
 *
 * AVI infoframe are transmitted at least once per two video field and
 * contains information about HDMI transmission mode such as color space,
 * colorimetry, ...
 *
 * @hdmi: pointer on the hdmi internal structure
 *
 * Return negative value if error occurs
 */
static int hdmi_avi_infoframe_config(struct sti_hdmi *hdmi)
{
        struct drm_display_mode *mode = &hdmi->mode;
        struct hdmi_avi_infoframe infoframe;
        u8 buffer[HDMI_INFOFRAME_SIZE(AVI)];
        int ret;

        DRM_DEBUG_DRIVER("\n");

        ret = drm_hdmi_avi_infoframe_from_display_mode(&infoframe, mode);
        if (ret < 0) {
                DRM_ERROR("failed to setup AVI infoframe: %d\n", ret);
                return ret;
        }

        /* fixed infoframe configuration not linked to the mode */
        infoframe.colorspace = HDMI_COLORSPACE_RGB;
        infoframe.quantization_range = HDMI_QUANTIZATION_RANGE_DEFAULT;
        infoframe.colorimetry = HDMI_COLORIMETRY_NONE;

        ret = hdmi_avi_infoframe_pack(&infoframe, buffer, sizeof(buffer));
        if (ret < 0) {
                DRM_ERROR("failed to pack AVI infoframe: %d\n", ret);
                return ret;
        }

        hdmi_infoframe_write_infopack(hdmi, buffer);

        return 0;
}

/**
 * Prepare and configure the AUDIO infoframe
 *
 * AUDIO infoframe are transmitted once per frame and
 * contains information about HDMI transmission mode such as audio codec,
 * sample size, ...
 *
 * @hdmi: pointer on the hdmi internal structure
 *
 * Return negative value if error occurs
 */
static int hdmi_audio_infoframe_config(struct sti_hdmi *hdmi)
{
        struct hdmi_audio_infoframe infofame;
        u8 buffer[HDMI_INFOFRAME_SIZE(AUDIO)];
        int ret;

        ret = hdmi_audio_infoframe_init(&infofame);
        if (ret < 0) {
                DRM_ERROR("failed to setup audio infoframe: %d\n", ret);
                return ret;
        }

        infofame.channels = 2;

        ret = hdmi_audio_infoframe_pack(&infofame, buffer, sizeof(buffer));
        if (ret < 0) {
                DRM_ERROR("failed to pack audio infoframe: %d\n", ret);
                return ret;
        }

        hdmi_infoframe_write_infopack(hdmi, buffer);

        return 0;
}

/**
 * Software reset of the hdmi subsystem
 *
 * @hdmi: pointer on the hdmi internal structure
 *
 */
#define HDMI_TIMEOUT_SWRESET  100   /*milliseconds */
static void hdmi_swreset(struct sti_hdmi *hdmi)
{
        u32 val;

        DRM_DEBUG_DRIVER("\n");

        /* Enable hdmi_audio clock only during hdmi reset */
        if (clk_prepare_enable(hdmi->clk_audio))
                DRM_INFO("Failed to prepare/enable hdmi_audio clk\n");

        /* Sw reset */
        hdmi->event_received = false;

        val = hdmi_read(hdmi, HDMI_CFG);
        val |= HDMI_CFG_SW_RST_EN;
        hdmi_write(hdmi, val, HDMI_CFG);

        /* Wait reset completed */
        wait_event_interruptible_timeout(hdmi->wait_event,
                                         hdmi->event_received == true,
                                         msecs_to_jiffies
                                         (HDMI_TIMEOUT_SWRESET));

        /*
         * HDMI_STA_SW_RST bit is set to '1' when SW_RST bit in HDMI_CFG is
         * set to '1' and clk_audio is running.
         */
        if ((hdmi_read(hdmi, HDMI_STA) & HDMI_STA_SW_RST) == 0)
                DRM_DEBUG_DRIVER("Warning: HDMI sw reset timeout occurs\n");

        val = hdmi_read(hdmi, HDMI_CFG);
        val &= ~HDMI_CFG_SW_RST_EN;
        hdmi_write(hdmi, val, HDMI_CFG);

        /* Disable hdmi_audio clock. Not used anymore for drm purpose */
        clk_disable_unprepare(hdmi->clk_audio);
}

static void sti_hdmi_disable(struct drm_bridge *bridge)
{
        struct sti_hdmi *hdmi = bridge->driver_private;

        u32 val = hdmi_read(hdmi, HDMI_CFG);

        if (!hdmi->enabled)
                return;

        DRM_DEBUG_DRIVER("\n");

        /* Disable HDMI */
        val &= ~HDMI_CFG_DEVICE_EN;
        hdmi_write(hdmi, val, HDMI_CFG);

        hdmi_write(hdmi, 0xffffffff, HDMI_INT_CLR);

        /* Stop the phy */
        hdmi->phy_ops->stop(hdmi);

        /* Set the default channel data to be a dark red */
        hdmi_write(hdmi, 0x0000, HDMI_DFLT_CHL0_DAT);
        hdmi_write(hdmi, 0x0000, HDMI_DFLT_CHL1_DAT);
        hdmi_write(hdmi, 0x0060, HDMI_DFLT_CHL2_DAT);

        /* Disable/unprepare hdmi clock */
        clk_disable_unprepare(hdmi->clk_phy);
        clk_disable_unprepare(hdmi->clk_tmds);
        clk_disable_unprepare(hdmi->clk_pix);

        hdmi->enabled = false;
}

static void sti_hdmi_pre_enable(struct drm_bridge *bridge)
{
        struct sti_hdmi *hdmi = bridge->driver_private;

        DRM_DEBUG_DRIVER("\n");

        if (hdmi->enabled)
                return;

        /* Prepare/enable clocks */
        if (clk_prepare_enable(hdmi->clk_pix))
                DRM_ERROR("Failed to prepare/enable hdmi_pix clk\n");
        if (clk_prepare_enable(hdmi->clk_tmds))
                DRM_ERROR("Failed to prepare/enable hdmi_tmds clk\n");
        if (clk_prepare_enable(hdmi->clk_phy))
                DRM_ERROR("Failed to prepare/enable hdmi_rejec_pll clk\n");

        hdmi->enabled = true;

        /* Program hdmi serializer and start phy */
        if (!hdmi->phy_ops->start(hdmi)) {
                DRM_ERROR("Unable to start hdmi phy\n");
                return;
        }

        /* Program hdmi active area */
        hdmi_active_area(hdmi);

        /* Enable working interrupts */
        hdmi_write(hdmi, HDMI_WORKING_INT, HDMI_INT_EN);

        /* Program hdmi config */
        hdmi_config(hdmi);

        /* Program AVI infoframe */
        if (hdmi_avi_infoframe_config(hdmi))
                DRM_ERROR("Unable to configure AVI infoframe\n");

        /* Program AUDIO infoframe */
        if (hdmi_audio_infoframe_config(hdmi))
                DRM_ERROR("Unable to configure AUDIO infoframe\n");

        /* Sw reset */
        hdmi_swreset(hdmi);
}

static void sti_hdmi_set_mode(struct drm_bridge *bridge,
                struct drm_display_mode *mode,
                struct drm_display_mode *adjusted_mode)
{
        struct sti_hdmi *hdmi = bridge->driver_private;
        int ret;

        DRM_DEBUG_DRIVER("\n");

        /* Copy the drm display mode in the connector local structure */
        memcpy(&hdmi->mode, mode, sizeof(struct drm_display_mode));

        /* Update clock framerate according to the selected mode */
        ret = clk_set_rate(hdmi->clk_pix, mode->clock * 1000);
        if (ret < 0) {
                DRM_ERROR("Cannot set rate (%dHz) for hdmi_pix clk\n",
                          mode->clock * 1000);
                return;
        }
        ret = clk_set_rate(hdmi->clk_phy, mode->clock * 1000);
        if (ret < 0) {
                DRM_ERROR("Cannot set rate (%dHz) for hdmi_rejection_pll clk\n",
                          mode->clock * 1000);
                return;
        }
}

static void sti_hdmi_bridge_nope(struct drm_bridge *bridge)
{
        /* do nothing */
}

static const struct drm_bridge_funcs sti_hdmi_bridge_funcs = {
        .pre_enable = sti_hdmi_pre_enable,
        .enable = sti_hdmi_bridge_nope,
        .disable = sti_hdmi_disable,
        .post_disable = sti_hdmi_bridge_nope,
        .mode_set = sti_hdmi_set_mode,
};

static int sti_hdmi_connector_get_modes(struct drm_connector *connector)
{
        struct sti_hdmi_connector *hdmi_connector
                = to_sti_hdmi_connector(connector);
        struct sti_hdmi *hdmi = hdmi_connector->hdmi;
        struct edid *edid;
        int count;

        DRM_DEBUG_DRIVER("\n");

        edid = drm_get_edid(connector, hdmi->ddc_adapt);
        if (!edid)
                goto fail;

        count = drm_add_edid_modes(connector, edid);
        drm_mode_connector_update_edid_property(connector, edid);

        kfree(edid);
        return count;

fail:
        DRM_ERROR("Can not read HDMI EDID\n");
        return 0;
}

#define CLK_TOLERANCE_HZ 50

static int sti_hdmi_connector_mode_valid(struct drm_connector *connector,
                                        struct drm_display_mode *mode)
{
        int target = mode->clock * 1000;
        int target_min = target - CLK_TOLERANCE_HZ;
        int target_max = target + CLK_TOLERANCE_HZ;
        int result;
        struct sti_hdmi_connector *hdmi_connector
                = to_sti_hdmi_connector(connector);
        struct sti_hdmi *hdmi = hdmi_connector->hdmi;


        result = clk_round_rate(hdmi->clk_pix, target);

        DRM_DEBUG_DRIVER("target rate = %d => available rate = %d\n",
                         target, result);

        if ((result < target_min) || (result > target_max)) {
                DRM_DEBUG_DRIVER("hdmi pixclk=%d not supported\n", target);
                return MODE_BAD;
        }

        return MODE_OK;
}

struct drm_encoder *sti_hdmi_best_encoder(struct drm_connector *connector)
{
        struct sti_hdmi_connector *hdmi_connector
                = to_sti_hdmi_connector(connector);

        /* Best encoder is the one associated during connector creation */
        return hdmi_connector->encoder;
}

static struct drm_connector_helper_funcs sti_hdmi_connector_helper_funcs = {
        .get_modes = sti_hdmi_connector_get_modes,
        .mode_valid = sti_hdmi_connector_mode_valid,
        .best_encoder = sti_hdmi_best_encoder,
};

/* get detection status of display device */
static enum drm_connector_status
sti_hdmi_connector_detect(struct drm_connector *connector, bool force)
{
        struct sti_hdmi_connector *hdmi_connector
                = to_sti_hdmi_connector(connector);
        struct sti_hdmi *hdmi = hdmi_connector->hdmi;

        DRM_DEBUG_DRIVER("\n");

        if (hdmi->hpd) {
                DRM_DEBUG_DRIVER("hdmi cable connected\n");
                return connector_status_connected;
        }

        DRM_DEBUG_DRIVER("hdmi cable disconnected\n");
        return connector_status_disconnected;
}

static void sti_hdmi_connector_destroy(struct drm_connector *connector)
{
        struct sti_hdmi_connector *hdmi_connector
                = to_sti_hdmi_connector(connector);

        drm_connector_unregister(connector);
        drm_connector_cleanup(connector);
        kfree(hdmi_connector);
}

static struct drm_connector_funcs sti_hdmi_connector_funcs = {
        .dpms = drm_atomic_helper_connector_dpms,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .detect = sti_hdmi_connector_detect,
        .destroy = sti_hdmi_connector_destroy,
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static struct drm_encoder *sti_hdmi_find_encoder(struct drm_device *dev)
{
        struct drm_encoder *encoder;

        list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
                if (encoder->encoder_type == DRM_MODE_ENCODER_TMDS)
                        return encoder;
        }

        return NULL;
}

static int sti_hdmi_bind(struct device *dev, struct device *master, void *data)
{
        struct sti_hdmi *hdmi = dev_get_drvdata(dev);
        struct drm_device *drm_dev = data;
        struct drm_encoder *encoder;
        struct sti_hdmi_connector *connector;
        struct drm_connector *drm_connector;
        struct drm_bridge *bridge;
        struct device_node *ddc;
        int err;

        ddc = of_parse_phandle(dev->of_node, "ddc", 0);
        if (ddc) {
                hdmi->ddc_adapt = of_find_i2c_adapter_by_node(ddc);
                if (!hdmi->ddc_adapt) {
                        err = -EPROBE_DEFER;
                        of_node_put(ddc);
                        return err;
                }

                of_node_put(ddc);
        }

        /* Set the drm device handle */
        hdmi->drm_dev = drm_dev;

        encoder = sti_hdmi_find_encoder(drm_dev);
        if (!encoder)
                goto err_adapt;

        connector = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
        if (!connector)
                goto err_adapt;


        connector->hdmi = hdmi;

        bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL);
        if (!bridge)
                goto err_adapt;

        bridge->driver_private = hdmi;
        bridge->funcs = &sti_hdmi_bridge_funcs;
        drm_bridge_attach(drm_dev, bridge);

        encoder->bridge = bridge;
        connector->encoder = encoder;

        drm_connector = (struct drm_connector *)connector;

        drm_connector->polled = DRM_CONNECTOR_POLL_HPD;

        drm_connector_init(drm_dev, drm_connector,
                        &sti_hdmi_connector_funcs, DRM_MODE_CONNECTOR_HDMIA);
        drm_connector_helper_add(drm_connector,
                        &sti_hdmi_connector_helper_funcs);

        err = drm_connector_register(drm_connector);
        if (err)
                goto err_connector;

        err = drm_mode_connector_attach_encoder(drm_connector, encoder);
        if (err) {
                DRM_ERROR("Failed to attach a connector to a encoder\n");
                goto err_sysfs;
        }

        /* Enable default interrupts */
        hdmi_write(hdmi, HDMI_DEFAULT_INT, HDMI_INT_EN);

        return 0;

err_sysfs:
        drm_connector_unregister(drm_connector);
err_connector:
        drm_connector_cleanup(drm_connector);
err_adapt:
        put_device(&hdmi->ddc_adapt->dev);
        return -EINVAL;
}

static void sti_hdmi_unbind(struct device *dev,
                struct device *master, void *data)
{
        /* do nothing */
}

static const struct component_ops sti_hdmi_ops = {
        .bind = sti_hdmi_bind,
        .unbind = sti_hdmi_unbind,
};

static const struct of_device_id hdmi_of_match[] = {
        {
                .compatible = "st,stih416-hdmi",
                .data = &tx3g0c55phy_ops,
        }, {
                .compatible = "st,stih407-hdmi",
                .data = &tx3g4c28phy_ops,
        }, {
                /* end node */
        }
};
MODULE_DEVICE_TABLE(of, hdmi_of_match);

static int sti_hdmi_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct sti_hdmi *hdmi;
        struct device_node *np = dev->of_node;
        struct resource *res;
        int ret;

        DRM_INFO("%s\n", __func__);

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

        hdmi->dev = pdev->dev;

        /* Get resources */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hdmi-reg");
        if (!res) {
                DRM_ERROR("Invalid hdmi resource\n");
                return -ENOMEM;
        }
        hdmi->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
        if (!hdmi->regs)
                return -ENOMEM;

        if (of_device_is_compatible(np, "st,stih416-hdmi")) {
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                                   "syscfg");
                if (!res) {
                        DRM_ERROR("Invalid syscfg resource\n");
                        return -ENOMEM;
                }
                hdmi->syscfg = devm_ioremap_nocache(dev, res->start,
                                                    resource_size(res));
                if (!hdmi->syscfg)
                        return -ENOMEM;

        }

        hdmi->phy_ops = (struct hdmi_phy_ops *)
                of_match_node(hdmi_of_match, np)->data;

        /* Get clock resources */
        hdmi->clk_pix = devm_clk_get(dev, "pix");
        if (IS_ERR(hdmi->clk_pix)) {
                DRM_ERROR("Cannot get hdmi_pix clock\n");
                return PTR_ERR(hdmi->clk_pix);
        }

        hdmi->clk_tmds = devm_clk_get(dev, "tmds");
        if (IS_ERR(hdmi->clk_tmds)) {
                DRM_ERROR("Cannot get hdmi_tmds clock\n");
                return PTR_ERR(hdmi->clk_tmds);
        }

        hdmi->clk_phy = devm_clk_get(dev, "phy");
        if (IS_ERR(hdmi->clk_phy)) {
                DRM_ERROR("Cannot get hdmi_phy clock\n");
                return PTR_ERR(hdmi->clk_phy);
        }

        hdmi->clk_audio = devm_clk_get(dev, "audio");
        if (IS_ERR(hdmi->clk_audio)) {
                DRM_ERROR("Cannot get hdmi_audio clock\n");
                return PTR_ERR(hdmi->clk_audio);
        }

        hdmi->hpd = readl(hdmi->regs + HDMI_STA) & HDMI_STA_HOT_PLUG;

        init_waitqueue_head(&hdmi->wait_event);

        hdmi->irq = platform_get_irq_byname(pdev, "irq");

        ret = devm_request_threaded_irq(dev, hdmi->irq, hdmi_irq,
                        hdmi_irq_thread, IRQF_ONESHOT, dev_name(dev), hdmi);
        if (ret) {
                DRM_ERROR("Failed to register HDMI interrupt\n");
                return ret;
        }

        hdmi->reset = devm_reset_control_get(dev, "hdmi");
        /* Take hdmi out of reset */
        if (!IS_ERR(hdmi->reset))
                reset_control_deassert(hdmi->reset);

        platform_set_drvdata(pdev, hdmi);

        return component_add(&pdev->dev, &sti_hdmi_ops);
}

static int sti_hdmi_remove(struct platform_device *pdev)
{
        struct sti_hdmi *hdmi = dev_get_drvdata(&pdev->dev);

        if (hdmi->ddc_adapt)
                put_device(&hdmi->ddc_adapt->dev);

        component_del(&pdev->dev, &sti_hdmi_ops);
        return 0;
}

struct platform_driver sti_hdmi_driver = {
        .driver = {
                .name = "sti-hdmi",
                .owner = THIS_MODULE,
                .of_match_table = hdmi_of_match,
        },
        .probe = sti_hdmi_probe,
        .remove = sti_hdmi_remove,
};

module_platform_driver(sti_hdmi_driver);

MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
MODULE_LICENSE("GPL");