// SPDX-License-Identifier: GPL-2.0
/*
 * Magnachip d53e6ea8966 MIPI-DSI panel driver
 * Copyright (C) 2023 Chris Morgan
 */

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

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>

#include <video/mipi_display.h>

/* Forward declaration for use in backlight function */
struct d53e6ea8966;

/* Panel info, unique to each panel */
struct d53e6ea8966_panel_info {
        /** @display_modes: the supported display modes */
        const struct drm_display_mode *display_modes;
        /** @num_modes: the number of supported display modes */
        unsigned int num_modes;
        /** @width_mm: panel width in mm */
        u16 width_mm;
        /** @height_mm: panel height in mm */
        u16 height_mm;
        /** @bus_flags: drm bus flags for panel */
        u32 bus_flags;
        /** @panel_init_seq: panel specific init sequence */
        void (*panel_init_seq)(struct d53e6ea8966 *db);
        /** @backlight_register: panel backlight registration or NULL */
        int (*backlight_register)(struct d53e6ea8966 *db);
};

struct d53e6ea8966 {
        /** @dev: the container device */
        struct device *dev;
        /** @dbi: the DBI bus abstraction handle */
        struct mipi_dbi dbi;
        /** @panel: the DRM panel instance for this device */
        struct drm_panel panel;
        /** @reset: reset GPIO line */
        struct gpio_desc *reset;
        /** @enable: enable GPIO line */
        struct gpio_desc *enable;
        /** @reg_vdd: VDD supply regulator for panel logic */
        struct regulator *reg_vdd;
        /** @reg_elvdd: ELVDD supply regulator for panel display */
        struct regulator *reg_elvdd;
        /** @dsi_dev: DSI child device (panel) */
        struct mipi_dsi_device *dsi_dev;
        /** @bl_dev: pseudo-backlight device for oled panel */
        struct backlight_device *bl_dev;
        /** @panel_info: struct containing panel timing and info */
        const struct d53e6ea8966_panel_info *panel_info;
};

#define NUM_GAMMA_LEVELS        16
#define GAMMA_TABLE_COUNT       23
#define MAX_BRIGHTNESS          (NUM_GAMMA_LEVELS - 1)

#define MCS_ELVSS_ON                    0xb1
#define MCS_TEMP_SWIRE                  0xb2
#define MCS_PASSWORD_0                  0xf0
#define MCS_PASSWORD_1                  0xf1
#define MCS_ANALOG_PWR_CTL_0            0xf4
#define MCS_ANALOG_PWR_CTL_1            0xf5
#define MCS_GTCON_SET                   0xf7
#define MCS_GATELESS_SIGNAL_SET         0xf8
#define MCS_SET_GAMMA                   0xf9

static inline struct d53e6ea8966 *to_d53e6ea8966(struct drm_panel *panel)
{
        return container_of(panel, struct d53e6ea8966, panel);
}

/* Table of gamma values provided in datasheet */
static u8 ams495qa01_gamma[NUM_GAMMA_LEVELS][GAMMA_TABLE_COUNT] = {
        {0x01, 0x79, 0x78, 0x8d, 0xd9, 0xdf, 0xd5, 0xcb, 0xcf, 0xc5,
         0xe5, 0xe0, 0xe4, 0xdc, 0xb8, 0xd4, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x7d, 0x7c, 0x92, 0xd7, 0xdd, 0xd2, 0xcb, 0xd0, 0xc6,
         0xe5, 0xe1, 0xe3, 0xda, 0xbd, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x7f, 0x7e, 0x95, 0xd7, 0xde, 0xd2, 0xcb, 0xcf, 0xc5,
         0xe5, 0xe3, 0xe3, 0xda, 0xbf, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x82, 0x81, 0x99, 0xd6, 0xdd, 0xd1, 0xca, 0xcf, 0xc3,
         0xe4, 0xe3, 0xe3, 0xda, 0xc2, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x84, 0x83, 0x9b, 0xd7, 0xde, 0xd2, 0xc8, 0xce, 0xc2,
         0xe4, 0xe3, 0xe2, 0xd9, 0xc3, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x87, 0x86, 0x9f, 0xd6, 0xdd, 0xd1, 0xc7, 0xce, 0xc1,
         0xe4, 0xe3, 0xe2, 0xd9, 0xc6, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x89, 0x89, 0xa2, 0xd5, 0xdb, 0xcf, 0xc8, 0xcf, 0xc2,
         0xe3, 0xe3, 0xe1, 0xd9, 0xc7, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x8b, 0x8b, 0xa5, 0xd5, 0xdb, 0xcf, 0xc7, 0xce, 0xc0,
         0xe3, 0xe3, 0xe1, 0xd8, 0xc7, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x8d, 0x8d, 0xa7, 0xd5, 0xdb, 0xcf, 0xc6, 0xce, 0xc0,
         0xe4, 0xe4, 0xe1, 0xd7, 0xc8, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x8f, 0x8f, 0xaa, 0xd4, 0xdb, 0xce, 0xc6, 0xcd, 0xbf,
         0xe3, 0xe3, 0xe1, 0xd7, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x91, 0x91, 0xac, 0xd3, 0xda, 0xce, 0xc5, 0xcd, 0xbe,
         0xe3, 0xe3, 0xe0, 0xd7, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x93, 0x93, 0xaf, 0xd3, 0xda, 0xcd, 0xc5, 0xcd, 0xbe,
         0xe2, 0xe3, 0xdf, 0xd6, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x95, 0x95, 0xb1, 0xd2, 0xd9, 0xcc, 0xc4, 0xcd, 0xbe,
         0xe2, 0xe3, 0xdf, 0xd7, 0xcc, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x99, 0x99, 0xb6, 0xd1, 0xd9, 0xcc, 0xc3, 0xcb, 0xbc,
         0xe2, 0xe4, 0xdf, 0xd6, 0xcc, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x9c, 0x9c, 0xba, 0xd0, 0xd8, 0xcb, 0xc3, 0xcb, 0xbb,
         0xe2, 0xe4, 0xdf, 0xd6, 0xce, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
        {0x01, 0x9f, 0x9f, 0xbe, 0xcf, 0xd7, 0xc9, 0xc2, 0xcb, 0xbb,
         0xe1, 0xe3, 0xde, 0xd6, 0xd0, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
         0x00, 0x2f},
};

/*
 * Table of elvss values provided in datasheet and corresponds to
 * gamma values.
 */
static u8 ams495qa01_elvss[NUM_GAMMA_LEVELS] = {
        0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15,
        0x15, 0x15, 0x14, 0x14, 0x13, 0x12,
};

static int ams495qa01_update_gamma(struct mipi_dbi *dbi, int brightness)
{
        int tmp = brightness;

        mipi_dbi_command_buf(dbi, MCS_SET_GAMMA, ams495qa01_gamma[tmp],
                             ARRAY_SIZE(ams495qa01_gamma[tmp]));
        mipi_dbi_command(dbi, MCS_SET_GAMMA, 0x00);

        /* Undocumented command */
        mipi_dbi_command(dbi, 0x26, 0x00);

        mipi_dbi_command(dbi, MCS_TEMP_SWIRE, ams495qa01_elvss[tmp]);

        return 0;
}

static void ams495qa01_panel_init(struct d53e6ea8966 *db)
{
        struct mipi_dbi *dbi = &db->dbi;

        mipi_dbi_command(dbi, MCS_PASSWORD_0, 0x5a, 0x5a);
        mipi_dbi_command(dbi, MCS_PASSWORD_1, 0x5a, 0x5a);

        /* Undocumented commands */
        mipi_dbi_command(dbi, 0xb0, 0x02);
        mipi_dbi_command(dbi, 0xf3, 0x3b);

        mipi_dbi_command(dbi, MCS_ANALOG_PWR_CTL_0, 0x33, 0x42, 0x00, 0x08);
        mipi_dbi_command(dbi, MCS_ANALOG_PWR_CTL_1, 0x00, 0x06, 0x26, 0x35, 0x03);

        /* Undocumented commands */
        mipi_dbi_command(dbi, 0xf6, 0x02);
        mipi_dbi_command(dbi, 0xc6, 0x0b, 0x00, 0x00, 0x3c, 0x00, 0x22,
                         0x00, 0x00, 0x00, 0x00);

        mipi_dbi_command(dbi, MCS_GTCON_SET, 0x20);
        mipi_dbi_command(dbi, MCS_TEMP_SWIRE, 0x06, 0x06, 0x06, 0x06);
        mipi_dbi_command(dbi, MCS_ELVSS_ON, 0x07, 0x00, 0x10);
        mipi_dbi_command(dbi, MCS_GATELESS_SIGNAL_SET, 0x7f, 0x7a,
                         0x89, 0x67, 0x26, 0x38, 0x00, 0x00, 0x09,
                         0x67, 0x70, 0x88, 0x7a, 0x76, 0x05, 0x09,
                         0x23, 0x23, 0x23);

        /* Undocumented commands */
        mipi_dbi_command(dbi, 0xb5, 0xff, 0xef, 0x35, 0x42, 0x0d, 0xd7,
                         0xff, 0x07, 0xff, 0xff, 0xfd, 0x00, 0x01,
                         0xff, 0x05, 0x12, 0x0f, 0xff, 0xff, 0xff,
                         0xff);
        mipi_dbi_command(dbi, 0xb4, 0x15);
        mipi_dbi_command(dbi, 0xb3, 0x00);

        ams495qa01_update_gamma(dbi, MAX_BRIGHTNESS);
}

static int d53e6ea8966_prepare(struct drm_panel *panel)
{
        struct d53e6ea8966 *db = to_d53e6ea8966(panel);
        int ret;

        /* Power up */
        ret = regulator_enable(db->reg_vdd);
        if (ret) {
                dev_err(db->dev, "failed to enable vdd regulator: %d\n", ret);
                return ret;
        }

        if (db->reg_elvdd) {
                ret = regulator_enable(db->reg_elvdd);
                if (ret) {
                        dev_err(db->dev,
                                "failed to enable elvdd regulator: %d\n", ret);
                        regulator_disable(db->reg_vdd);
                        return ret;
                }
        }

        /* Enable */
        if (db->enable)
                gpiod_set_value_cansleep(db->enable, 1);

        msleep(50);

        /* Reset */
        gpiod_set_value_cansleep(db->reset, 1);
        usleep_range(1000, 5000);
        gpiod_set_value_cansleep(db->reset, 0);
        msleep(20);

        db->panel_info->panel_init_seq(db);

        return 0;
}

static int d53e6ea8966_enable(struct drm_panel *panel)
{
        struct d53e6ea8966 *db = to_d53e6ea8966(panel);
        struct mipi_dbi *dbi = &db->dbi;

        mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
        msleep(200);
        mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
        usleep_range(10000, 15000);

        return 0;
}

static int d53e6ea8966_disable(struct drm_panel *panel)
{
        struct d53e6ea8966 *db = to_d53e6ea8966(panel);
        struct mipi_dbi *dbi = &db->dbi;

        mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
        msleep(20);
        mipi_dbi_command(dbi, MIPI_DCS_ENTER_SLEEP_MODE);
        msleep(100);

        return 0;
}

static int d53e6ea8966_unprepare(struct drm_panel *panel)
{
        struct d53e6ea8966 *db = to_d53e6ea8966(panel);

        if (db->enable)
                gpiod_set_value_cansleep(db->enable, 0);

        gpiod_set_value_cansleep(db->reset, 1);

        if (db->reg_elvdd)
                regulator_disable(db->reg_elvdd);

        regulator_disable(db->reg_vdd);
        msleep(100);

        return 0;
}

static int d53e6ea8966_get_modes(struct drm_panel *panel,
                                 struct drm_connector *connector)
{
        struct d53e6ea8966 *db = to_d53e6ea8966(panel);
        const struct d53e6ea8966_panel_info *panel_info = db->panel_info;
        struct drm_display_mode *mode;
        static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
        unsigned int i;

        for (i = 0; i < panel_info->num_modes; i++) {
                mode = drm_mode_duplicate(connector->dev,
                                          &panel_info->display_modes[i]);
                if (!mode)
                        return -ENOMEM;

                drm_mode_set_name(mode);
                drm_mode_probed_add(connector, mode);
        }

        connector->display_info.bpc = 8;
        connector->display_info.width_mm = panel_info->width_mm;
        connector->display_info.height_mm = panel_info->height_mm;
        connector->display_info.bus_flags = panel_info->bus_flags;

        drm_display_info_set_bus_formats(&connector->display_info,
                                         &bus_format, 1);

        return 1;
}

static const struct drm_panel_funcs d53e6ea8966_panel_funcs = {
        .disable = d53e6ea8966_disable,
        .enable = d53e6ea8966_enable,
        .get_modes = d53e6ea8966_get_modes,
        .prepare = d53e6ea8966_prepare,
        .unprepare = d53e6ea8966_unprepare,
};

static int ams495qa01_set_brightness(struct backlight_device *bd)
{
        struct d53e6ea8966 *db = bl_get_data(bd);
        struct mipi_dbi *dbi = &db->dbi;
        int brightness = backlight_get_brightness(bd);

        ams495qa01_update_gamma(dbi, brightness);

        return 0;
}

static const struct backlight_ops ams495qa01_backlight_ops = {
        .update_status  = ams495qa01_set_brightness,
};

static int ams495qa01_backlight_register(struct d53e6ea8966 *db)
{
        struct backlight_properties props = {
                .type           = BACKLIGHT_RAW,
                .brightness     = MAX_BRIGHTNESS,
                .max_brightness = MAX_BRIGHTNESS,
        };
        struct device *dev = db->dev;
        int ret = 0;

        db->bl_dev = devm_backlight_device_register(dev, "panel", dev, db,
                                                    &ams495qa01_backlight_ops,
                                                    &props);
        if (IS_ERR(db->bl_dev)) {
                ret = PTR_ERR(db->bl_dev);
                dev_err(dev, "error registering backlight device (%d)\n", ret);
        }

        return ret;
}

static int d53e6ea8966_probe(struct spi_device *spi)
{
        struct device *dev = &spi->dev;
        struct mipi_dsi_host *dsi_host;
        struct d53e6ea8966 *db;
        int ret;
        struct mipi_dsi_device_info info = {
                .type = "d53e6ea8966",
                .channel = 0,
                .node = NULL,
        };

        db = devm_drm_panel_alloc(dev, struct d53e6ea8966, panel,
                                  &d53e6ea8966_panel_funcs,
                                  DRM_MODE_CONNECTOR_DSI);
        if (IS_ERR(db))
                return PTR_ERR(db);

        spi_set_drvdata(spi, db);

        db->dev = dev;

        db->panel_info = of_device_get_match_data(dev);
        if (!db->panel_info)
                return -EINVAL;

        db->reg_vdd = devm_regulator_get(dev, "vdd");
        if (IS_ERR(db->reg_vdd))
                return dev_err_probe(dev, PTR_ERR(db->reg_vdd),
                                     "Failed to get vdd supply\n");

        db->reg_elvdd = devm_regulator_get_optional(dev, "elvdd");
        if (IS_ERR(db->reg_elvdd))
                db->reg_elvdd = NULL;

        db->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(db->reset)) {
                ret = PTR_ERR(db->reset);
                return dev_err_probe(dev, ret, "no RESET GPIO\n");
        }

        db->enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
        if (IS_ERR(db->enable)) {
                ret = PTR_ERR(db->enable);
                return dev_err_probe(dev, ret, "cannot get ENABLE GPIO\n");
        }

        ret = mipi_dbi_spi_init(spi, &db->dbi, NULL);
        if (ret)
                return dev_err_probe(dev, ret, "MIPI DBI init failed\n");

        dsi_host = drm_of_get_dsi_bus(dev);
        if (IS_ERR(dsi_host)) {
                ret = PTR_ERR(dsi_host);
                return dev_err_probe(dev, ret, "Error attaching DSI bus\n");
        }

        db->dsi_dev = devm_mipi_dsi_device_register_full(dev, dsi_host, &info);
        if (IS_ERR(db->dsi_dev)) {
                dev_err(dev, "failed to register dsi device: %ld\n",
                        PTR_ERR(db->dsi_dev));
                return PTR_ERR(db->dsi_dev);
        }

        db->dsi_dev->lanes = 2;
        db->dsi_dev->format = MIPI_DSI_FMT_RGB888;
        db->dsi_dev->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
                          MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;

        if (db->panel_info->backlight_register) {
                ret = db->panel_info->backlight_register(db);
                if (ret < 0)
                        return ret;
                db->panel.backlight = db->bl_dev;
        }

        drm_panel_add(&db->panel);

        ret = devm_mipi_dsi_attach(dev, db->dsi_dev);
        if (ret < 0) {
                dev_err(dev, "mipi_dsi_attach failed: %d\n", ret);
                drm_panel_remove(&db->panel);
                return ret;
        }

        return 0;
}

static void d53e6ea8966_remove(struct spi_device *spi)
{
        struct d53e6ea8966 *db = spi_get_drvdata(spi);

        drm_panel_remove(&db->panel);
}

static const struct drm_display_mode ams495qa01_modes[] = {
        { /* 60hz */
                .clock = 33500,
                .hdisplay = 960,
                .hsync_start = 960 + 10,
                .hsync_end = 960 + 10 + 2,
                .htotal = 960 + 10 + 2 + 10,
                .vdisplay = 544,
                .vsync_start = 544 + 10,
                .vsync_end = 544 + 10 + 2,
                .vtotal = 544 + 10 + 2 + 10,
                .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
                .type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
                },
        { /* 50hz */
                .clock = 27800,
                .hdisplay = 960,
                .hsync_start = 960 + 10,
                .hsync_end = 960 + 10 + 2,
                .htotal = 960 + 10 + 2 + 10,
                .vdisplay = 544,
                .vsync_start = 544 + 10,
                .vsync_end = 544 + 10 + 2,
                .vtotal = 544 + 10 + 2 + 10,
                .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
                .type = DRM_MODE_TYPE_DRIVER,
        },
};

static const struct d53e6ea8966_panel_info ams495qa01_info = {
        .display_modes = ams495qa01_modes,
        .num_modes = ARRAY_SIZE(ams495qa01_modes),
        .width_mm = 117,
        .height_mm = 74,
        .bus_flags = DRM_BUS_FLAG_DE_LOW | DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
        .panel_init_seq = ams495qa01_panel_init,
        .backlight_register = ams495qa01_backlight_register,
};

static const struct of_device_id d53e6ea8966_match[] = {
        { .compatible = "samsung,ams495qa01", .data = &ams495qa01_info },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, d53e6ea8966_match);

static const struct spi_device_id d53e6ea8966_ids[] = {
        { "ams495qa01", 0 },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(spi, d53e6ea8966_ids);

static struct spi_driver d53e6ea8966_driver = {
        .driver         = {
                .name   = "d53e6ea8966-panel",
                .of_match_table = d53e6ea8966_match,
        },
        .id_table       = d53e6ea8966_ids,
        .probe          = d53e6ea8966_probe,
        .remove         = d53e6ea8966_remove,
};
module_spi_driver(d53e6ea8966_driver);

MODULE_AUTHOR("Chris Morgan <macromorgan@hotmail.com>");
MODULE_DESCRIPTION("Magnachip d53e6ea8966 panel driver");
MODULE_LICENSE("GPL");