// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2016 InforceComputing
 * Copyright (C) 2016 Linaro Ltd
 * Copyright (C) 2023 BayLibre, SAS
 *
 * Authors:
 * - Vinay Simha BN <simhavcs@gmail.com>
 * - Sumit Semwal <sumit.semwal@linaro.org>
 * - Guillaume La Roque <glaroque@baylibre.com>
 *
 */

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>

#include <video/mipi_display.h>

#include <drm/drm_mipi_dsi.h>
#include <drm/drm_modes.h>
#include <drm/drm_panel.h>

#define DSI_REG_MCAP    0xb0
#define DSI_REG_IS      0xb3 /* Interface Setting */
#define DSI_REG_IIS     0xb4 /* Interface ID Setting */
#define DSI_REG_CTRL    0xb6

enum {
        IOVCC = 0,
        POWER = 1
};

struct stk_panel {
        const struct drm_display_mode *mode;
        struct backlight_device *backlight;
        struct drm_panel base;
        struct gpio_desc *enable_gpio; /* Power IC supply enable */
        struct gpio_desc *reset_gpio; /* External reset */
        struct mipi_dsi_device *dsi;
        struct regulator_bulk_data supplies[2];
};

static inline struct stk_panel *to_stk_panel(struct drm_panel *panel)
{
        return container_of(panel, struct stk_panel, base);
}

static int stk_panel_init(struct stk_panel *stk)
{
        struct mipi_dsi_device *dsi = stk->dsi;
        struct mipi_dsi_multi_context dsi_ctx = {.dsi = dsi};

        mipi_dsi_dcs_soft_reset_multi(&dsi_ctx);
        mipi_dsi_msleep(&dsi_ctx, 5);
        mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
        mipi_dsi_msleep(&dsi_ctx, 120);

        mipi_dsi_generic_write_seq_multi(&dsi_ctx, DSI_REG_MCAP, 0x04);

        /* Interface setting, video mode */
        mipi_dsi_generic_write_seq_multi(&dsi_ctx, DSI_REG_IS, 0x14, 0x08, 0x00, 0x22, 0x00);
        mipi_dsi_generic_write_seq_multi(&dsi_ctx, DSI_REG_IIS, 0x0c, 0x00);
        mipi_dsi_generic_write_seq_multi(&dsi_ctx, DSI_REG_CTRL, 0x3a, 0xd3);

        mipi_dsi_dcs_set_display_brightness_multi(&dsi_ctx, 0x77);

        mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_WRITE_CONTROL_DISPLAY,
                                     MIPI_DCS_WRITE_MEMORY_START);

        mipi_dsi_dcs_set_pixel_format_multi(&dsi_ctx, 0x77);
        mipi_dsi_dcs_set_column_address_multi(&dsi_ctx, 0, stk->mode->hdisplay - 1);
        mipi_dsi_dcs_set_page_address_multi(&dsi_ctx, 0, stk->mode->vdisplay - 1);

        return dsi_ctx.accum_err;
}

static int stk_panel_on(struct stk_panel *stk)
{
        struct mipi_dsi_device *dsi = stk->dsi;
        struct mipi_dsi_multi_context dsi_ctx = {.dsi = dsi};

        mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);

        mipi_dsi_msleep(&dsi_ctx, 20);

        return dsi_ctx.accum_err;
}

static void stk_panel_off(struct stk_panel *stk)
{
        struct mipi_dsi_device *dsi = stk->dsi;
        struct mipi_dsi_multi_context dsi_ctx = {.dsi = dsi};

        dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;

        mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
        mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);

        mipi_dsi_msleep(&dsi_ctx, 100);
}

static int stk_panel_unprepare(struct drm_panel *panel)
{
        struct stk_panel *stk = to_stk_panel(panel);

        stk_panel_off(stk);
        regulator_bulk_disable(ARRAY_SIZE(stk->supplies), stk->supplies);
        gpiod_set_value(stk->reset_gpio, 0);
        gpiod_set_value(stk->enable_gpio, 1);

        return 0;
}

static int stk_panel_prepare(struct drm_panel *panel)
{
        struct stk_panel *stk = to_stk_panel(panel);
        int ret;

        gpiod_set_value(stk->reset_gpio, 0);
        gpiod_set_value(stk->enable_gpio, 0);
        ret = regulator_enable(stk->supplies[IOVCC].consumer);
        if (ret < 0)
                return ret;

        mdelay(8);
        ret = regulator_enable(stk->supplies[POWER].consumer);
        if (ret < 0)
                goto iovccoff;

        mdelay(20);
        gpiod_set_value(stk->enable_gpio, 1);
        mdelay(20);
        gpiod_set_value(stk->reset_gpio, 1);
        mdelay(10);
        ret = stk_panel_init(stk);
        if (ret < 0)
                goto poweroff;

        ret = stk_panel_on(stk);
        if (ret < 0)
                goto poweroff;

        return 0;

poweroff:
        regulator_disable(stk->supplies[POWER].consumer);
iovccoff:
        regulator_disable(stk->supplies[IOVCC].consumer);
        gpiod_set_value(stk->reset_gpio, 0);
        gpiod_set_value(stk->enable_gpio, 0);

        return ret;
}

static const struct drm_display_mode default_mode = {
                .clock = 163204,
                .hdisplay = 1200,
                .hsync_start = 1200 + 144,
                .hsync_end = 1200 + 144 + 16,
                .htotal = 1200 + 144 + 16 + 45,
                .vdisplay = 1920,
                .vsync_start = 1920 + 8,
                .vsync_end = 1920 + 8 + 4,
                .vtotal = 1920 + 8 + 4 + 4,
                .width_mm = 95,
                .height_mm = 151,
};

static int stk_panel_get_modes(struct drm_panel *panel,
                               struct drm_connector *connector)
{
        struct drm_display_mode *mode;

        mode = drm_mode_duplicate(connector->dev, &default_mode);
        if (!mode) {
                dev_err(panel->dev, "failed to add mode %ux%ux@%u\n",
                        default_mode.hdisplay, default_mode.vdisplay,
                        drm_mode_vrefresh(&default_mode));
                return -ENOMEM;
        }

        drm_mode_set_name(mode);
        drm_mode_probed_add(connector, mode);
        connector->display_info.width_mm = default_mode.width_mm;
        connector->display_info.height_mm = default_mode.height_mm;
        return 1;
}

static int dsi_dcs_bl_get_brightness(struct backlight_device *bl)
{
        struct mipi_dsi_device *dsi = bl_get_data(bl);
        int ret;
        u16 brightness;

        dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
        ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
        if (ret < 0)
                return ret;

        dsi->mode_flags |= MIPI_DSI_MODE_LPM;
        return brightness & 0xff;
}

static int dsi_dcs_bl_update_status(struct backlight_device *bl)
{
        struct mipi_dsi_device *dsi = bl_get_data(bl);
        struct mipi_dsi_multi_context dsi_ctx = {.dsi = dsi};

        dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
        mipi_dsi_dcs_set_display_brightness_multi(&dsi_ctx, bl->props.brightness);
        if (dsi_ctx.accum_err)
                return dsi_ctx.accum_err;

        dsi->mode_flags |= MIPI_DSI_MODE_LPM;
        return dsi_ctx.accum_err;
}

static const struct backlight_ops dsi_bl_ops = {
        .update_status = dsi_dcs_bl_update_status,
        .get_brightness = dsi_dcs_bl_get_brightness,
};

static struct backlight_device *
drm_panel_create_dsi_backlight(struct mipi_dsi_device *dsi)
{
        struct device *dev = &dsi->dev;
        struct backlight_properties props = {
                .type = BACKLIGHT_RAW,
                .brightness = 255,
                .max_brightness = 255,
        };

        return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
                                              &dsi_bl_ops, &props);
}

static const struct drm_panel_funcs stk_panel_funcs = {
        .unprepare = stk_panel_unprepare,
        .prepare = stk_panel_prepare,
        .get_modes = stk_panel_get_modes,
};

static const struct of_device_id stk_of_match[] = {
        { .compatible = "startek,kd070fhfid015", },
        { }
};
MODULE_DEVICE_TABLE(of, stk_of_match);

static int stk_panel_add(struct stk_panel *stk)
{
        struct device *dev = &stk->dsi->dev;
        int ret;

        stk->mode = &default_mode;

        stk->supplies[IOVCC].supply = "iovcc";
        stk->supplies[POWER].supply = "power";
        ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(stk->supplies), stk->supplies);
        if (ret) {
                dev_err(dev, "regulator_bulk failed\n");
                return ret;
        }

        stk->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
        if (IS_ERR(stk->reset_gpio)) {
                ret = PTR_ERR(stk->reset_gpio);
                dev_err(dev, "cannot get reset-gpios %d\n", ret);
                return ret;
        }

        stk->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
        if (IS_ERR(stk->enable_gpio)) {
                ret = PTR_ERR(stk->enable_gpio);
                dev_err(dev, "cannot get enable-gpio %d\n", ret);
                return ret;
        }

        stk->backlight = drm_panel_create_dsi_backlight(stk->dsi);
        if (IS_ERR(stk->backlight)) {
                ret = PTR_ERR(stk->backlight);
                dev_err(dev, "failed to register backlight %d\n", ret);
                return ret;
        }

        drm_panel_init(&stk->base, &stk->dsi->dev, &stk_panel_funcs,
                       DRM_MODE_CONNECTOR_DSI);

        drm_panel_add(&stk->base);

        return 0;
}

static int stk_panel_probe(struct mipi_dsi_device *dsi)
{
        struct stk_panel *stk;
        int ret;

        dsi->lanes = 4;
        dsi->format = MIPI_DSI_FMT_RGB888;
        dsi->mode_flags = (MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_LPM);

        stk = devm_kzalloc(&dsi->dev, sizeof(*stk), GFP_KERNEL);
        if (!stk)
                return -ENOMEM;

        mipi_dsi_set_drvdata(dsi, stk);

        stk->dsi = dsi;

        ret = stk_panel_add(stk);
        if (ret < 0)
                return ret;

        ret = mipi_dsi_attach(dsi);
        if (ret < 0)
                drm_panel_remove(&stk->base);

        return 0;
}

static void stk_panel_remove(struct mipi_dsi_device *dsi)
{
        struct stk_panel *stk = mipi_dsi_get_drvdata(dsi);
        int err;

        err = mipi_dsi_detach(dsi);
        if (err < 0)
                dev_err(&dsi->dev, "failed to detach from DSI host: %d\n",
                        err);

        drm_panel_remove(&stk->base);
}

static struct mipi_dsi_driver stk_panel_driver = {
        .driver = {
                .name = "panel-startek-kd070fhfid015",
                .of_match_table = stk_of_match,
        },
        .probe = stk_panel_probe,
        .remove = stk_panel_remove,
};
module_mipi_dsi_driver(stk_panel_driver);

MODULE_AUTHOR("Guillaume La Roque <glaroque@baylibre.com>");
MODULE_DESCRIPTION("STARTEK KD070FHFID015");
MODULE_LICENSE("GPL");