// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018, The Linux Foundation. All rights reserved.
 * Copyright (c) 2019-2020. Linaro Limited.
 */

#include <linux/firmware.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/wait.h>
#include <linux/workqueue.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_edid.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

#include <drm/display/drm_hdmi_audio_helper.h>

#define EDID_BLOCK_SIZE 128
#define EDID_NUM_BLOCKS 2

#define FW_FILE "lt9611uxc_fw.bin"

struct lt9611uxc {
        struct device *dev;
        struct drm_bridge bridge;
        struct drm_bridge *next_bridge;

        struct regmap *regmap;
        /* Protects all accesses to registers by stopping the on-chip MCU */
        struct mutex ocm_lock;

        struct wait_queue_head wq;
        struct work_struct work;

        struct device_node *dsi0_node;
        struct device_node *dsi1_node;
        struct mipi_dsi_device *dsi0;
        struct mipi_dsi_device *dsi1;

        struct gpio_desc *reset_gpio;
        struct gpio_desc *enable_gpio;

        struct regulator_bulk_data supplies[2];

        struct i2c_client *client;

        bool hpd_supported;
        bool edid_read;
        /* can be accessed from different threads, so protect this with ocm_lock */
        bool hdmi_connected;
        uint8_t fw_version;
};

#define LT9611_PAGE_CONTROL     0xff

static const struct regmap_range_cfg lt9611uxc_ranges[] = {
        {
                .name = "register_range",
                .range_min =  0,
                .range_max = 0xd0ff,
                .selector_reg = LT9611_PAGE_CONTROL,
                .selector_mask = 0xff,
                .selector_shift = 0,
                .window_start = 0,
                .window_len = 0x100,
        },
};

static const struct regmap_config lt9611uxc_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0xffff,
        .ranges = lt9611uxc_ranges,
        .num_ranges = ARRAY_SIZE(lt9611uxc_ranges),
};

struct lt9611uxc_mode {
        u16 hdisplay;
        u16 vdisplay;
        u8 vrefresh;
};

/*
 * This chip supports only a fixed set of modes.
 * Enumerate them here to check whether the mode is supported.
 */
static struct lt9611uxc_mode lt9611uxc_modes[] = {
        { 1920, 1080, 60 },
        { 1920, 1080, 30 },
        { 1920, 1080, 25 },
        { 1366, 768, 60 },
        { 1360, 768, 60 },
        { 1280, 1024, 60 },
        { 1280, 800, 60 },
        { 1280, 720, 60 },
        { 1280, 720, 50 },
        { 1280, 720, 30 },
        { 1152, 864, 60 },
        { 1024, 768, 60 },
        { 800, 600, 60 },
        { 720, 576, 50 },
        { 720, 480, 60 },
        { 640, 480, 60 },
};

static struct lt9611uxc *bridge_to_lt9611uxc(struct drm_bridge *bridge)
{
        return container_of(bridge, struct lt9611uxc, bridge);
}

static void lt9611uxc_lock(struct lt9611uxc *lt9611uxc)
{
        mutex_lock(&lt9611uxc->ocm_lock);
        regmap_write(lt9611uxc->regmap, 0x80ee, 0x01);
}

static void lt9611uxc_unlock(struct lt9611uxc *lt9611uxc)
{
        regmap_write(lt9611uxc->regmap, 0x80ee, 0x00);
        msleep(50);
        mutex_unlock(&lt9611uxc->ocm_lock);
}

static irqreturn_t lt9611uxc_irq_thread_handler(int irq, void *dev_id)
{
        struct lt9611uxc *lt9611uxc = dev_id;
        unsigned int irq_status = 0;
        unsigned int hpd_status = 0;

        lt9611uxc_lock(lt9611uxc);

        regmap_read(lt9611uxc->regmap, 0xb022, &irq_status);
        regmap_read(lt9611uxc->regmap, 0xb023, &hpd_status);
        if (irq_status)
                regmap_write(lt9611uxc->regmap, 0xb022, 0);

        if (irq_status & BIT(0)) {
                lt9611uxc->edid_read = !!(hpd_status & BIT(0));
                wake_up_all(&lt9611uxc->wq);
        }

        if (irq_status & BIT(1)) {
                lt9611uxc->hdmi_connected = hpd_status & BIT(1);
                schedule_work(&lt9611uxc->work);
        }

        lt9611uxc_unlock(lt9611uxc);

        return IRQ_HANDLED;
}

static void lt9611uxc_hpd_work(struct work_struct *work)
{
        struct lt9611uxc *lt9611uxc = container_of(work, struct lt9611uxc, work);
        bool connected;

        mutex_lock(&lt9611uxc->ocm_lock);
        connected = lt9611uxc->hdmi_connected;
        mutex_unlock(&lt9611uxc->ocm_lock);

        drm_bridge_hpd_notify(&lt9611uxc->bridge,
                              connected ?
                              connector_status_connected :
                              connector_status_disconnected);
}

static void lt9611uxc_reset(struct lt9611uxc *lt9611uxc)
{
        gpiod_set_value_cansleep(lt9611uxc->reset_gpio, 1);
        msleep(20);

        gpiod_set_value_cansleep(lt9611uxc->reset_gpio, 0);
        msleep(20);

        gpiod_set_value_cansleep(lt9611uxc->reset_gpio, 1);
        msleep(300);
}

static void lt9611uxc_assert_5v(struct lt9611uxc *lt9611uxc)
{
        if (!lt9611uxc->enable_gpio)
                return;

        gpiod_set_value_cansleep(lt9611uxc->enable_gpio, 1);
        msleep(20);
}

static int lt9611uxc_regulator_init(struct lt9611uxc *lt9611uxc)
{
        int ret;

        lt9611uxc->supplies[0].supply = "vdd";
        lt9611uxc->supplies[1].supply = "vcc";

        ret = devm_regulator_bulk_get(lt9611uxc->dev, 2, lt9611uxc->supplies);
        if (ret < 0)
                return ret;

        return regulator_set_load(lt9611uxc->supplies[0].consumer, 200000);
}

static int lt9611uxc_regulator_enable(struct lt9611uxc *lt9611uxc)
{
        int ret;

        ret = regulator_enable(lt9611uxc->supplies[0].consumer);
        if (ret < 0)
                return ret;

        usleep_range(1000, 10000); /* 50000 according to dtsi */

        ret = regulator_enable(lt9611uxc->supplies[1].consumer);
        if (ret < 0) {
                regulator_disable(lt9611uxc->supplies[0].consumer);
                return ret;
        }

        return 0;
}

static struct lt9611uxc_mode *lt9611uxc_find_mode(const struct drm_display_mode *mode)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(lt9611uxc_modes); i++) {
                if (lt9611uxc_modes[i].hdisplay == mode->hdisplay &&
                    lt9611uxc_modes[i].vdisplay == mode->vdisplay &&
                    lt9611uxc_modes[i].vrefresh == drm_mode_vrefresh(mode)) {
                        return &lt9611uxc_modes[i];
                }
        }

        return NULL;
}

static struct mipi_dsi_device *lt9611uxc_attach_dsi(struct lt9611uxc *lt9611uxc,
                                                    struct device_node *dsi_node)
{
        const struct mipi_dsi_device_info info = { "lt9611uxc", 0, NULL };
        struct mipi_dsi_device *dsi;
        struct mipi_dsi_host *host;
        struct device *dev = lt9611uxc->dev;
        int ret;

        host = of_find_mipi_dsi_host_by_node(dsi_node);
        if (!host)
                return ERR_PTR(dev_err_probe(dev, -EPROBE_DEFER, "failed to find dsi host\n"));

        dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
        if (IS_ERR(dsi)) {
                dev_err(dev, "failed to create dsi device\n");
                return dsi;
        }

        dsi->lanes = 4;
        dsi->format = MIPI_DSI_FMT_RGB888;
        dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
                          MIPI_DSI_MODE_VIDEO_HSE;

        ret = devm_mipi_dsi_attach(dev, dsi);
        if (ret < 0) {
                dev_err(dev, "failed to attach dsi to host\n");
                return ERR_PTR(ret);
        }

        return dsi;
}

static int lt9611uxc_bridge_attach(struct drm_bridge *bridge,
                                   struct drm_encoder *encoder,
                                   enum drm_bridge_attach_flags flags)
{
        struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);

        return drm_bridge_attach(encoder, lt9611uxc->next_bridge,
                                 bridge, flags);
}

static enum drm_mode_status
lt9611uxc_bridge_mode_valid(struct drm_bridge *bridge,
                            const struct drm_display_info *info,
                            const struct drm_display_mode *mode)
{
        struct lt9611uxc_mode *lt9611uxc_mode;

        lt9611uxc_mode = lt9611uxc_find_mode(mode);

        return lt9611uxc_mode ? MODE_OK : MODE_BAD;
}

static void lt9611uxc_video_setup(struct lt9611uxc *lt9611uxc,
                                  const struct drm_display_mode *mode)
{
        u32 h_total, hactive, hsync_len, hfront_porch;
        u32 v_total, vactive, vsync_len, vfront_porch;

        h_total = mode->htotal;
        v_total = mode->vtotal;

        hactive = mode->hdisplay;
        hsync_len = mode->hsync_end - mode->hsync_start;
        hfront_porch = mode->hsync_start - mode->hdisplay;

        vactive = mode->vdisplay;
        vsync_len = mode->vsync_end - mode->vsync_start;
        vfront_porch = mode->vsync_start - mode->vdisplay;

        regmap_write(lt9611uxc->regmap, 0xd00d, (u8)(v_total / 256));
        regmap_write(lt9611uxc->regmap, 0xd00e, (u8)(v_total % 256));

        regmap_write(lt9611uxc->regmap, 0xd00f, (u8)(vactive / 256));
        regmap_write(lt9611uxc->regmap, 0xd010, (u8)(vactive % 256));

        regmap_write(lt9611uxc->regmap, 0xd011, (u8)(h_total / 256));
        regmap_write(lt9611uxc->regmap, 0xd012, (u8)(h_total % 256));

        regmap_write(lt9611uxc->regmap, 0xd013, (u8)(hactive / 256));
        regmap_write(lt9611uxc->regmap, 0xd014, (u8)(hactive % 256));

        regmap_write(lt9611uxc->regmap, 0xd015, (u8)(vsync_len % 256));

        regmap_update_bits(lt9611uxc->regmap, 0xd016, 0xf, (u8)(hsync_len / 256));
        regmap_write(lt9611uxc->regmap, 0xd017, (u8)(hsync_len % 256));

        regmap_update_bits(lt9611uxc->regmap, 0xd018, 0xf, (u8)(vfront_porch / 256));
        regmap_write(lt9611uxc->regmap, 0xd019, (u8)(vfront_porch % 256));

        regmap_update_bits(lt9611uxc->regmap, 0xd01a, 0xf, (u8)(hfront_porch / 256));
        regmap_write(lt9611uxc->regmap, 0xd01b, (u8)(hfront_porch % 256));
}

static void lt9611uxc_bridge_mode_set(struct drm_bridge *bridge,
                                      const struct drm_display_mode *mode,
                                      const struct drm_display_mode *adj_mode)
{
        struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);

        lt9611uxc_lock(lt9611uxc);
        lt9611uxc_video_setup(lt9611uxc, mode);
        lt9611uxc_unlock(lt9611uxc);
}

static enum drm_connector_status
lt9611uxc_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector)
{
        struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
        unsigned int reg_val = 0;
        int ret;
        bool connected = true;

        lt9611uxc_lock(lt9611uxc);

        if (lt9611uxc->hpd_supported) {
                ret = regmap_read(lt9611uxc->regmap, 0xb023, &reg_val);

                if (ret)
                        dev_err(lt9611uxc->dev, "failed to read hpd status: %d\n", ret);
                else
                        connected  = reg_val & BIT(1);
        }
        lt9611uxc->hdmi_connected = connected;

        lt9611uxc_unlock(lt9611uxc);

        return connected ?  connector_status_connected :
                                connector_status_disconnected;
}

static int lt9611uxc_wait_for_edid(struct lt9611uxc *lt9611uxc)
{
        return wait_event_interruptible_timeout(lt9611uxc->wq, lt9611uxc->edid_read,
                        msecs_to_jiffies(500));
}

static int lt9611uxc_get_edid_block(void *data, u8 *buf, unsigned int block, size_t len)
{
        struct lt9611uxc *lt9611uxc = data;
        int ret;

        if (len > EDID_BLOCK_SIZE)
                return -EINVAL;

        if (block >= EDID_NUM_BLOCKS)
                return -EINVAL;

        lt9611uxc_lock(lt9611uxc);

        regmap_write(lt9611uxc->regmap, 0xb00b, 0x10);

        regmap_write(lt9611uxc->regmap, 0xb00a, block * EDID_BLOCK_SIZE);

        ret = regmap_noinc_read(lt9611uxc->regmap, 0xb0b0, buf, len);
        if (ret)
                dev_err(lt9611uxc->dev, "edid read failed: %d\n", ret);

        lt9611uxc_unlock(lt9611uxc);

        return 0;
};

static const struct drm_edid *lt9611uxc_bridge_edid_read(struct drm_bridge *bridge,
                                                         struct drm_connector *connector)
{
        struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
        int ret;

        ret = lt9611uxc_wait_for_edid(lt9611uxc);
        if (ret < 0) {
                dev_err(lt9611uxc->dev, "wait for EDID failed: %d\n", ret);
                return NULL;
        } else if (ret == 0) {
                dev_err(lt9611uxc->dev, "wait for EDID timeout\n");
                return NULL;
        }

        return drm_edid_read_custom(connector, lt9611uxc_get_edid_block, lt9611uxc);
}

static void lt9611uxc_bridge_hpd_notify(struct drm_bridge *bridge,
                                        struct drm_connector *connector,
                                        enum drm_connector_status status)
{
        const struct drm_edid *drm_edid;

        if (status == connector_status_disconnected) {
                drm_connector_hdmi_audio_plugged_notify(connector, false);
                drm_edid_connector_update(connector, NULL);
                return;
        }

        drm_edid = lt9611uxc_bridge_edid_read(bridge, connector);
        drm_edid_connector_update(connector, drm_edid);
        drm_edid_free(drm_edid);

        if (status == connector_status_connected)
                drm_connector_hdmi_audio_plugged_notify(connector, true);
}

static int lt9611uxc_hdmi_audio_prepare(struct drm_bridge *bridge,
                                        struct drm_connector *connector,
                                        struct hdmi_codec_daifmt *fmt,
                                        struct hdmi_codec_params *hparms)
{
        /*
         * LT9611UXC will automatically detect rate and sample size, so no need
         * to setup anything here.
         */
        return 0;
}

static void lt9611uxc_hdmi_audio_shutdown(struct drm_bridge *bridge,
                                          struct drm_connector *connector)
{
}

static const struct drm_bridge_funcs lt9611uxc_bridge_funcs = {
        .attach = lt9611uxc_bridge_attach,
        .mode_valid = lt9611uxc_bridge_mode_valid,
        .mode_set = lt9611uxc_bridge_mode_set,
        .detect = lt9611uxc_bridge_detect,
        .edid_read = lt9611uxc_bridge_edid_read,
        .hpd_notify = lt9611uxc_bridge_hpd_notify,
        .hdmi_audio_prepare = lt9611uxc_hdmi_audio_prepare,
        .hdmi_audio_shutdown = lt9611uxc_hdmi_audio_shutdown,
};

static int lt9611uxc_parse_dt(struct device *dev,
                              struct lt9611uxc *lt9611uxc)
{
        lt9611uxc->dsi0_node = of_graph_get_remote_node(dev->of_node, 0, -1);
        if (!lt9611uxc->dsi0_node) {
                dev_err(lt9611uxc->dev, "failed to get remote node for primary dsi\n");
                return -ENODEV;
        }

        lt9611uxc->dsi1_node = of_graph_get_remote_node(dev->of_node, 1, -1);

        return drm_of_find_panel_or_bridge(dev->of_node, 2, -1, NULL, &lt9611uxc->next_bridge);
}

static int lt9611uxc_gpio_init(struct lt9611uxc *lt9611uxc)
{
        struct device *dev = lt9611uxc->dev;

        lt9611uxc->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(lt9611uxc->reset_gpio)) {
                dev_err(dev, "failed to acquire reset gpio\n");
                return PTR_ERR(lt9611uxc->reset_gpio);
        }

        lt9611uxc->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
        if (IS_ERR(lt9611uxc->enable_gpio)) {
                dev_err(dev, "failed to acquire enable gpio\n");
                return PTR_ERR(lt9611uxc->enable_gpio);
        }

        return 0;
}

static int lt9611uxc_read_device_rev(struct lt9611uxc *lt9611uxc)
{
        unsigned int rev0, rev1, rev2;
        int ret;

        lt9611uxc_lock(lt9611uxc);

        ret = regmap_read(lt9611uxc->regmap, 0x8100, &rev0);
        ret |= regmap_read(lt9611uxc->regmap, 0x8101, &rev1);
        ret |= regmap_read(lt9611uxc->regmap, 0x8102, &rev2);
        if (ret)
                dev_err(lt9611uxc->dev, "failed to read revision: %d\n", ret);
        else
                dev_info(lt9611uxc->dev, "LT9611 revision: 0x%02x.%02x.%02x\n", rev0, rev1, rev2);

        lt9611uxc_unlock(lt9611uxc);

        return ret;
}

static int lt9611uxc_read_version(struct lt9611uxc *lt9611uxc)
{
        unsigned int rev;
        int ret;

        lt9611uxc_lock(lt9611uxc);

        ret = regmap_read(lt9611uxc->regmap, 0xb021, &rev);
        if (ret)
                dev_err(lt9611uxc->dev, "failed to read revision: %d\n", ret);
        else
                dev_info(lt9611uxc->dev, "LT9611 version: 0x%02x\n", rev);

        lt9611uxc_unlock(lt9611uxc);

        return ret < 0 ? ret : rev;
}

#define LT9611UXC_FW_PAGE_SIZE 32
static void lt9611uxc_firmware_write_page(struct lt9611uxc *lt9611uxc, u16 addr, const u8 *buf)
{
        struct reg_sequence seq_write_prepare[] = {
                REG_SEQ0(0x805a, 0x04),
                REG_SEQ0(0x805a, 0x00),

                REG_SEQ0(0x805e, 0xdf),
                REG_SEQ0(0x805a, 0x20),
                REG_SEQ0(0x805a, 0x00),
                REG_SEQ0(0x8058, 0x21),
        };

        struct reg_sequence seq_write_addr[] = {
                REG_SEQ0(0x805b, (addr >> 16) & 0xff),
                REG_SEQ0(0x805c, (addr >> 8) & 0xff),
                REG_SEQ0(0x805d, addr & 0xff),
                REG_SEQ0(0x805a, 0x10),
                REG_SEQ0(0x805a, 0x00),
        };

        regmap_write(lt9611uxc->regmap, 0x8108, 0xbf);
        msleep(20);
        regmap_write(lt9611uxc->regmap, 0x8108, 0xff);
        msleep(20);
        regmap_multi_reg_write(lt9611uxc->regmap, seq_write_prepare, ARRAY_SIZE(seq_write_prepare));
        regmap_noinc_write(lt9611uxc->regmap, 0x8059, buf, LT9611UXC_FW_PAGE_SIZE);
        regmap_multi_reg_write(lt9611uxc->regmap, seq_write_addr, ARRAY_SIZE(seq_write_addr));
        msleep(20);
}

static void lt9611uxc_firmware_read_page(struct lt9611uxc *lt9611uxc, u16 addr, char *buf)
{
        struct reg_sequence seq_read_page[] = {
                REG_SEQ0(0x805a, 0xa0),
                REG_SEQ0(0x805a, 0x80),
                REG_SEQ0(0x805b, (addr >> 16) & 0xff),
                REG_SEQ0(0x805c, (addr >> 8) & 0xff),
                REG_SEQ0(0x805d, addr & 0xff),
                REG_SEQ0(0x805a, 0x90),
                REG_SEQ0(0x805a, 0x80),
                REG_SEQ0(0x8058, 0x21),
        };

        regmap_multi_reg_write(lt9611uxc->regmap, seq_read_page, ARRAY_SIZE(seq_read_page));
        regmap_noinc_read(lt9611uxc->regmap, 0x805f, buf, LT9611UXC_FW_PAGE_SIZE);
}

static char *lt9611uxc_firmware_read(struct lt9611uxc *lt9611uxc, size_t size)
{
        struct reg_sequence seq_read_setup[] = {
                REG_SEQ0(0x805a, 0x84),
                REG_SEQ0(0x805a, 0x80),
        };

        char *readbuf;
        u16 offset;

        readbuf = kzalloc(ALIGN(size, 32), GFP_KERNEL);
        if (!readbuf)
                return NULL;

        regmap_multi_reg_write(lt9611uxc->regmap, seq_read_setup, ARRAY_SIZE(seq_read_setup));

        for (offset = 0;
             offset < size;
             offset += LT9611UXC_FW_PAGE_SIZE)
                lt9611uxc_firmware_read_page(lt9611uxc, offset, &readbuf[offset]);

        return readbuf;
}

static int lt9611uxc_firmware_update(struct lt9611uxc *lt9611uxc)
{
        int ret;
        u16 offset;
        size_t remain;
        char *readbuf;
        const struct firmware *fw;

        struct reg_sequence seq_setup[] = {
                REG_SEQ0(0x805e, 0xdf),
                REG_SEQ0(0x8058, 0x00),
                REG_SEQ0(0x8059, 0x50),
                REG_SEQ0(0x805a, 0x10),
                REG_SEQ0(0x805a, 0x00),
        };


        struct reg_sequence seq_block_erase[] = {
                REG_SEQ0(0x805a, 0x04),
                REG_SEQ0(0x805a, 0x00),
                REG_SEQ0(0x805b, 0x00),
                REG_SEQ0(0x805c, 0x00),
                REG_SEQ0(0x805d, 0x00),
                REG_SEQ0(0x805a, 0x01),
                REG_SEQ0(0x805a, 0x00),
        };

        ret = request_firmware(&fw, FW_FILE, lt9611uxc->dev);
        if (ret < 0)
                return ret;

        dev_info(lt9611uxc->dev, "Updating firmware\n");
        lt9611uxc_lock(lt9611uxc);

        regmap_multi_reg_write(lt9611uxc->regmap, seq_setup, ARRAY_SIZE(seq_setup));

        /*
         * Need erase block 2 timess here. Sometimes, block erase can fail.
         * This is a workaroud.
         */
        regmap_multi_reg_write(lt9611uxc->regmap, seq_block_erase, ARRAY_SIZE(seq_block_erase));
        msleep(3000);
        regmap_multi_reg_write(lt9611uxc->regmap, seq_block_erase, ARRAY_SIZE(seq_block_erase));
        msleep(3000);

        for (offset = 0, remain = fw->size;
             remain >= LT9611UXC_FW_PAGE_SIZE;
             offset += LT9611UXC_FW_PAGE_SIZE, remain -= LT9611UXC_FW_PAGE_SIZE)
                lt9611uxc_firmware_write_page(lt9611uxc, offset, fw->data + offset);

        if (remain > 0) {
                char buf[LT9611UXC_FW_PAGE_SIZE];

                memset(buf, 0xff, LT9611UXC_FW_PAGE_SIZE);
                memcpy(buf, fw->data + offset, remain);
                lt9611uxc_firmware_write_page(lt9611uxc, offset, buf);
        }
        msleep(20);

        readbuf = lt9611uxc_firmware_read(lt9611uxc, fw->size);
        if (!readbuf) {
                ret = -ENOMEM;
                goto out;
        }

        if (!memcmp(readbuf, fw->data, fw->size)) {
                dev_err(lt9611uxc->dev, "Firmware update failed\n");
                print_hex_dump(KERN_ERR, "fw: ", DUMP_PREFIX_OFFSET, 16, 1, readbuf, fw->size, false);
                ret = -EINVAL;
        } else {
                dev_info(lt9611uxc->dev, "Firmware updates successfully\n");
                ret = 0;
        }
        kfree(readbuf);

out:
        lt9611uxc_unlock(lt9611uxc);
        lt9611uxc_reset(lt9611uxc);
        release_firmware(fw);

        return ret;
}

static ssize_t lt9611uxc_firmware_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len)
{
        struct lt9611uxc *lt9611uxc = dev_get_drvdata(dev);
        int ret;

        ret = lt9611uxc_firmware_update(lt9611uxc);
        if (ret < 0)
                return ret;
        return len;
}

static ssize_t lt9611uxc_firmware_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct lt9611uxc *lt9611uxc = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%02x\n", lt9611uxc->fw_version);
}

static DEVICE_ATTR_RW(lt9611uxc_firmware);

static struct attribute *lt9611uxc_attrs[] = {
        &dev_attr_lt9611uxc_firmware.attr,
        NULL,
};

static const struct attribute_group lt9611uxc_attr_group = {
        .attrs = lt9611uxc_attrs,
};

static const struct attribute_group *lt9611uxc_attr_groups[] = {
        &lt9611uxc_attr_group,
        NULL,
};

static int lt9611uxc_probe(struct i2c_client *client)
{
        struct lt9611uxc *lt9611uxc;
        struct device *dev = &client->dev;
        int ret;
        bool fw_updated = false;

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
                dev_err(dev, "device doesn't support I2C\n");
                return -ENODEV;
        }

        lt9611uxc = devm_drm_bridge_alloc(dev, struct lt9611uxc, bridge, &lt9611uxc_bridge_funcs);
        if (IS_ERR(lt9611uxc))
                return PTR_ERR(lt9611uxc);

        lt9611uxc->dev = dev;
        lt9611uxc->client = client;
        mutex_init(&lt9611uxc->ocm_lock);

        lt9611uxc->regmap = devm_regmap_init_i2c(client, &lt9611uxc_regmap_config);
        if (IS_ERR(lt9611uxc->regmap)) {
                dev_err(lt9611uxc->dev, "regmap i2c init failed\n");
                return PTR_ERR(lt9611uxc->regmap);
        }

        ret = lt9611uxc_parse_dt(dev, lt9611uxc);
        if (ret) {
                dev_err(dev, "failed to parse device tree\n");
                return ret;
        }

        ret = lt9611uxc_gpio_init(lt9611uxc);
        if (ret < 0)
                goto err_of_put;

        ret = lt9611uxc_regulator_init(lt9611uxc);
        if (ret < 0)
                goto err_of_put;

        lt9611uxc_assert_5v(lt9611uxc);

        ret = lt9611uxc_regulator_enable(lt9611uxc);
        if (ret)
                goto err_of_put;

        lt9611uxc_reset(lt9611uxc);

        ret = lt9611uxc_read_device_rev(lt9611uxc);
        if (ret) {
                dev_err(dev, "failed to read chip rev\n");
                goto err_disable_regulators;
        }

retry:
        ret = lt9611uxc_read_version(lt9611uxc);
        if (ret < 0) {
                dev_err(dev, "failed to read FW version\n");
                goto err_disable_regulators;
        } else if (ret == 0) {
                if (!fw_updated) {
                        fw_updated = true;
                        dev_err(dev, "FW version 0, enforcing firmware update\n");
                        ret = lt9611uxc_firmware_update(lt9611uxc);
                        if (ret < 0)
                                goto err_disable_regulators;
                        else
                                goto retry;
                } else {
                        dev_err(dev, "FW version 0, update failed\n");
                        ret = -EOPNOTSUPP;
                        goto err_disable_regulators;
                }
        } else if (ret < 0x40) {
                dev_info(dev, "FW version 0x%x, HPD not supported\n", ret);
        } else {
                lt9611uxc->hpd_supported = true;
        }
        lt9611uxc->fw_version = ret;

        init_waitqueue_head(&lt9611uxc->wq);
        INIT_WORK(&lt9611uxc->work, lt9611uxc_hpd_work);

        ret = request_threaded_irq(client->irq, NULL,
                                   lt9611uxc_irq_thread_handler,
                                   IRQF_ONESHOT, "lt9611uxc", lt9611uxc);
        if (ret) {
                dev_err(dev, "failed to request irq\n");
                goto err_disable_regulators;
        }

        i2c_set_clientdata(client, lt9611uxc);

        lt9611uxc->bridge.of_node = client->dev.of_node;
        lt9611uxc->bridge.ops = DRM_BRIDGE_OP_DETECT |
                DRM_BRIDGE_OP_EDID |
                DRM_BRIDGE_OP_HDMI_AUDIO;
        if (lt9611uxc->hpd_supported)
                lt9611uxc->bridge.ops |= DRM_BRIDGE_OP_HPD;
        lt9611uxc->bridge.type = DRM_MODE_CONNECTOR_HDMIA;

        lt9611uxc->bridge.hdmi_audio_dev = dev;
        lt9611uxc->bridge.hdmi_audio_max_i2s_playback_channels = 2;
        lt9611uxc->bridge.hdmi_audio_dai_port = 2;

        drm_bridge_add(&lt9611uxc->bridge);

        /* Attach primary DSI */
        lt9611uxc->dsi0 = lt9611uxc_attach_dsi(lt9611uxc, lt9611uxc->dsi0_node);
        if (IS_ERR(lt9611uxc->dsi0)) {
                ret = PTR_ERR(lt9611uxc->dsi0);
                goto err_remove_bridge;
        }

        /* Attach secondary DSI, if specified */
        if (lt9611uxc->dsi1_node) {
                lt9611uxc->dsi1 = lt9611uxc_attach_dsi(lt9611uxc, lt9611uxc->dsi1_node);
                if (IS_ERR(lt9611uxc->dsi1)) {
                        ret = PTR_ERR(lt9611uxc->dsi1);
                        goto err_remove_bridge;
                }
        }

        return 0;

err_remove_bridge:
        free_irq(client->irq, lt9611uxc);
        cancel_work_sync(&lt9611uxc->work);
        drm_bridge_remove(&lt9611uxc->bridge);

err_disable_regulators:
        regulator_bulk_disable(ARRAY_SIZE(lt9611uxc->supplies), lt9611uxc->supplies);

err_of_put:
        of_node_put(lt9611uxc->dsi1_node);
        of_node_put(lt9611uxc->dsi0_node);

        return ret;
}

static void lt9611uxc_remove(struct i2c_client *client)
{
        struct lt9611uxc *lt9611uxc = i2c_get_clientdata(client);

        free_irq(client->irq, lt9611uxc);
        cancel_work_sync(&lt9611uxc->work);
        drm_bridge_remove(&lt9611uxc->bridge);

        mutex_destroy(&lt9611uxc->ocm_lock);

        regulator_bulk_disable(ARRAY_SIZE(lt9611uxc->supplies), lt9611uxc->supplies);

        of_node_put(lt9611uxc->dsi1_node);
        of_node_put(lt9611uxc->dsi0_node);
}

static const struct i2c_device_id lt9611uxc_id[] = {
        { "lontium,lt9611uxc" },
        { /* sentinel */ }
};

static const struct of_device_id lt9611uxc_match_table[] = {
        { .compatible = "lontium,lt9611uxc" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, lt9611uxc_match_table);

static struct i2c_driver lt9611uxc_driver = {
        .driver = {
                .name = "lt9611uxc",
                .of_match_table = lt9611uxc_match_table,
                .dev_groups = lt9611uxc_attr_groups,
        },
        .probe = lt9611uxc_probe,
        .remove = lt9611uxc_remove,
        .id_table = lt9611uxc_id,
};
module_i2c_driver(lt9611uxc_driver);

MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
MODULE_DESCRIPTION("Lontium LT9611UXC DSI/HDMI bridge driver");
MODULE_LICENSE("GPL v2");

MODULE_FIRMWARE(FW_FILE);