// SPDX-License-Identifier: GPL-2.0
/*
 * Panel driver for the WideChips WS2401 480x800 DPI RGB panel, used in
 * the Samsung Mobile Display (SMD) LMS380KF01.
 * Found in the Samsung Galaxy Ace 2 GT-I8160 mobile phone.
 * Linus Walleij <linus.walleij@linaro.org>
 * Inspired by code and know-how in the vendor driver by Gareth Phillips.
 */
#include <drm/drm_mipi_dbi.h>
#include <drm/drm_modes.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/regulator/consumer.h>
#include <linux/spi/spi.h>

#include <video/mipi_display.h>

#define WS2401_RESCTL                   0xb8 /* Resolution select control */
#define WS2401_PSMPS                    0xbd /* SMPS positive control */
#define WS2401_NSMPS                    0xbe /* SMPS negative control */
#define WS2401_SMPS                     0xbf
#define WS2401_BCMODE                   0xc1 /* Backlight control mode */
#define WS2401_WRBLCTL                  0xc3 /* Backlight control */
#define WS2401_WRDISBV                  0xc4 /* Write manual brightness */
#define WS2401_WRCTRLD                  0xc6 /* Write BL control */
#define WS2401_WRMIE                    0xc7 /* Write MIE mode */
#define WS2401_READ_ID1                 0xda /* Read panel ID 1 */
#define WS2401_READ_ID2                 0xdb /* Read panel ID 2 */
#define WS2401_READ_ID3                 0xdc /* Read panel ID 3 */
#define WS2401_GAMMA_R1                 0xe7 /* Gamma red 1 */
#define WS2401_GAMMA_G1                 0xe8 /* Gamma green 1 */
#define WS2401_GAMMA_B1                 0xe9 /* Gamma blue 1 */
#define WS2401_GAMMA_R2                 0xea /* Gamma red 2 */
#define WS2401_GAMMA_G2                 0xeb /* Gamma green 2 */
#define WS2401_GAMMA_B2                 0xec /* Gamma blue 2 */
#define WS2401_PASSWD1                  0xf0 /* Password command for level 2 */
#define WS2401_DISCTL                   0xf2 /* Display control */
#define WS2401_PWRCTL                   0xf3 /* Power control */
#define WS2401_VCOMCTL                  0xf4 /* VCOM control */
#define WS2401_SRCCTL                   0xf5 /* Source control */
#define WS2401_PANELCTL                 0xf6 /* Panel control */

static const u8 ws2401_dbi_read_commands[] = {
        WS2401_READ_ID1,
        WS2401_READ_ID2,
        WS2401_READ_ID3,
        0, /* sentinel */
};

/**
 * struct ws2401 - state container for a panel controlled by the WS2401
 * controller
 */
struct ws2401 {
        /** @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;
        /** @width: the width of this panel in mm */
        u32 width;
        /** @height: the height of this panel in mm */
        u32 height;
        /** @reset: reset GPIO line */
        struct gpio_desc *reset;
        /** @regulators: VCCIO and VIO supply regulators */
        struct regulator_bulk_data regulators[2];
        /** @internal_bl: If using internal backlight */
        bool internal_bl;
};

static const struct drm_display_mode lms380kf01_480_800_mode = {
        /*
         * The vendor driver states that the "SMD panel" has a clock
         * frequency of 49920000 Hz / 2 = 24960000 Hz.
         */
        .clock = 24960,
        .hdisplay = 480,
        .hsync_start = 480 + 8,
        .hsync_end = 480 + 8 + 10,
        .htotal = 480 + 8 + 10 + 8,
        .vdisplay = 800,
        .vsync_start = 800 + 8,
        .vsync_end = 800 + 8 + 2,
        .vtotal = 800 + 8 + 2 + 18,
        .width_mm = 50,
        .height_mm = 84,
        .flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
};

static inline struct ws2401 *to_ws2401(struct drm_panel *panel)
{
        return container_of(panel, struct ws2401, panel);
}

static void ws2401_read_mtp_id(struct ws2401 *ws)
{
        struct mipi_dbi *dbi = &ws->dbi;
        u8 id1, id2, id3;
        int ret;

        ret = mipi_dbi_command_read(dbi, WS2401_READ_ID1, &id1);
        if (ret) {
                dev_err(ws->dev, "unable to read MTP ID 1\n");
                return;
        }
        ret = mipi_dbi_command_read(dbi, WS2401_READ_ID2, &id2);
        if (ret) {
                dev_err(ws->dev, "unable to read MTP ID 2\n");
                return;
        }
        ret = mipi_dbi_command_read(dbi, WS2401_READ_ID3, &id3);
        if (ret) {
                dev_err(ws->dev, "unable to read MTP ID 3\n");
                return;
        }
        dev_info(ws->dev, "MTP ID: %02x %02x %02x\n", id1, id2, id3);
}

static int ws2401_power_on(struct ws2401 *ws)
{
        struct mipi_dbi *dbi = &ws->dbi;
        int ret;

        /* Power up */
        ret = regulator_bulk_enable(ARRAY_SIZE(ws->regulators),
                                    ws->regulators);
        if (ret) {
                dev_err(ws->dev, "failed to enable regulators: %d\n", ret);
                return ret;
        }
        msleep(10);

        /* Assert reset >=1 ms */
        gpiod_set_value_cansleep(ws->reset, 1);
        usleep_range(1000, 5000);
        /* De-assert reset */
        gpiod_set_value_cansleep(ws->reset, 0);
        /* Wait >= 10 ms */
        msleep(10);
        dev_dbg(ws->dev, "de-asserted RESET\n");

        /*
         * Exit sleep mode and initialize display - some hammering is
         * necessary.
         */
        mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
        mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
        msleep(50);

        /* Magic to unlock level 2 control of the display */
        mipi_dbi_command(dbi, WS2401_PASSWD1, 0x5a, 0x5a);
        /* Configure resolution to 480RGBx800 */
        mipi_dbi_command(dbi, WS2401_RESCTL, 0x12);
        /* Set addressing mode Flip V(d0), Flip H(d1) RGB/BGR(d3) */
        mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, 0x01);
        /* Set pixel format: 24 bpp */
        mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x70);
        mipi_dbi_command(dbi, WS2401_SMPS, 0x00, 0x0f);
        mipi_dbi_command(dbi, WS2401_PSMPS, 0x06, 0x03, /* DDVDH: 4.6v */
                         0x7e, 0x03, 0x12, 0x37);
        mipi_dbi_command(dbi, WS2401_NSMPS, 0x06, 0x03, /* DDVDH: -4.6v */
                         0x7e, 0x02, 0x15, 0x37);
        mipi_dbi_command(dbi, WS2401_SMPS, 0x02, 0x0f);
        mipi_dbi_command(dbi, WS2401_PWRCTL, 0x10, 0xA9, 0x00, 0x01, 0x44,
                         0xb4,  /* VGH:16.1v, VGL:-13.8v */
                         0x50,  /* GREFP:4.2v (default) */
                         0x50,  /* GREFN:-4.2v (default) */
                         0x00,
                         0x44); /* VOUTL:-10v (default) */
        mipi_dbi_command(dbi, WS2401_DISCTL, 0x01, 0x00, 0x00, 0x00, 0x14,
                         0x16);
        mipi_dbi_command(dbi, WS2401_VCOMCTL, 0x30, 0x53, 0x53);
        mipi_dbi_command(dbi, WS2401_SRCCTL, 0x03, 0x0C, 0x00, 0x00, 0x00,
                         0x01,  /* 2 dot inversion */
                         0x01, 0x06, 0x03);
        mipi_dbi_command(dbi, WS2401_PANELCTL, 0x14, 0x00, 0x80, 0x00);
        mipi_dbi_command(dbi, WS2401_WRMIE, 0x01);

        /* Set up gamma, probably these are P-gamma and N-gamma for each color */
        mipi_dbi_command(dbi, WS2401_GAMMA_R1, 0x00,
                         0x5b, 0x42, 0x41, 0x3f, 0x42, 0x3d, 0x38, 0x2e,
                         0x2b, 0x2a, 0x27, 0x22, 0x27, 0x0f, 0x00, 0x00);
        mipi_dbi_command(dbi, WS2401_GAMMA_R2, 0x00,
                         0x5b, 0x42, 0x41, 0x3f, 0x42, 0x3d, 0x38, 0x2e,
                         0x2b, 0x2a, 0x27, 0x22, 0x27, 0x0f, 0x00, 0x00);
        mipi_dbi_command(dbi, WS2401_GAMMA_G1, 0x00,
                         0x59, 0x40, 0x3f, 0x3e, 0x41, 0x3d, 0x39, 0x2f,
                         0x2c, 0x2b, 0x29, 0x25, 0x29, 0x19, 0x08, 0x00);
        mipi_dbi_command(dbi, WS2401_GAMMA_G2, 0x00,
                         0x59, 0x40, 0x3f, 0x3e, 0x41, 0x3d, 0x39, 0x2f,
                         0x2c, 0x2b, 0x29, 0x25, 0x29, 0x19, 0x08, 0x00);
        mipi_dbi_command(dbi, WS2401_GAMMA_B1, 0x00,
                         0x57, 0x3b, 0x3a, 0x3b, 0x3f, 0x3b, 0x38, 0x27,
                         0x38, 0x2a, 0x26, 0x22, 0x34, 0x0c, 0x09, 0x00);
        mipi_dbi_command(dbi, WS2401_GAMMA_B2, 0x00,
                         0x57, 0x3b, 0x3a, 0x3b, 0x3f, 0x3b, 0x38, 0x27,
                         0x38, 0x2a, 0x26, 0x22, 0x34, 0x0c, 0x09, 0x00);

        if (ws->internal_bl) {
                mipi_dbi_command(dbi, WS2401_WRCTRLD, 0x2c);
        } else {
                mipi_dbi_command(dbi, WS2401_WRCTRLD, 0x00);
                /*
                 * When not using internal backlight we do not need any further
                 * L2 accesses to the panel so we close the door on our way out.
                 * Otherwise we need to leave the L2 door open.
                 */
                mipi_dbi_command(dbi, WS2401_PASSWD1, 0xa5, 0xa5);
        }

        return 0;
}

static int ws2401_power_off(struct ws2401 *ws)
{
        /* Go into RESET and disable regulators */
        gpiod_set_value_cansleep(ws->reset, 1);
        return regulator_bulk_disable(ARRAY_SIZE(ws->regulators),
                                      ws->regulators);
}

static int ws2401_unprepare(struct drm_panel *panel)
{
        struct ws2401 *ws = to_ws2401(panel);
        struct mipi_dbi *dbi = &ws->dbi;

        /* Make sure we disable backlight, if any */
        if (ws->internal_bl)
                mipi_dbi_command(dbi, WS2401_WRCTRLD, 0x00);
        mipi_dbi_command(dbi, MIPI_DCS_ENTER_SLEEP_MODE);
        msleep(120);
        return ws2401_power_off(to_ws2401(panel));
}

static int ws2401_disable(struct drm_panel *panel)
{
        struct ws2401 *ws = to_ws2401(panel);
        struct mipi_dbi *dbi = &ws->dbi;

        mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
        msleep(25);

        return 0;
}

static int ws2401_prepare(struct drm_panel *panel)
{
        return ws2401_power_on(to_ws2401(panel));
}

static int ws2401_enable(struct drm_panel *panel)
{
        struct ws2401 *ws = to_ws2401(panel);
        struct mipi_dbi *dbi = &ws->dbi;

        mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);

        return 0;
}

/**
 * ws2401_get_modes() - return the mode
 * @panel: the panel to get the mode for
 * @connector: reference to the central DRM connector control structure
 */
static int ws2401_get_modes(struct drm_panel *panel,
                            struct drm_connector *connector)
{
        struct ws2401 *ws = to_ws2401(panel);
        struct drm_display_mode *mode;
        static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;

        /*
         * We just support the LMS380KF01 so far, if we implement more panels
         * this mode, the following connector display_info settings and
         * probably the custom DCS sequences needs to selected based on what
         * the target panel needs.
         */
        mode = drm_mode_duplicate(connector->dev, &lms380kf01_480_800_mode);
        if (!mode) {
                dev_err(ws->dev, "failed to add mode\n");
                return -ENOMEM;
        }

        connector->display_info.bpc = 8;
        connector->display_info.width_mm = mode->width_mm;
        connector->display_info.height_mm = mode->height_mm;
        connector->display_info.bus_flags =
                DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE;
        drm_display_info_set_bus_formats(&connector->display_info,
                                         &bus_format, 1);

        drm_mode_set_name(mode);
        mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;

        drm_mode_probed_add(connector, mode);

        return 1;
}

static const struct drm_panel_funcs ws2401_drm_funcs = {
        .disable = ws2401_disable,
        .unprepare = ws2401_unprepare,
        .prepare = ws2401_prepare,
        .enable = ws2401_enable,
        .get_modes = ws2401_get_modes,
};

static int ws2401_set_brightness(struct backlight_device *bl)
{
        struct ws2401 *ws = bl_get_data(bl);
        struct mipi_dbi *dbi = &ws->dbi;
        u8 brightness = backlight_get_brightness(bl);

        if (backlight_is_blank(bl)) {
                mipi_dbi_command(dbi, WS2401_WRCTRLD, 0x00);
        } else {
                mipi_dbi_command(dbi, WS2401_WRCTRLD, 0x2c);
                mipi_dbi_command(dbi, WS2401_WRDISBV, brightness);
        }

        return 0;
}

static const struct backlight_ops ws2401_bl_ops = {
        .update_status = ws2401_set_brightness,
};

static const struct backlight_properties ws2401_bl_props = {
        .type = BACKLIGHT_PLATFORM,
        .brightness = 120,
        .max_brightness = U8_MAX,
};

static int ws2401_probe(struct spi_device *spi)
{
        struct device *dev = &spi->dev;
        struct ws2401 *ws;
        int ret;

        ws = devm_drm_panel_alloc(dev, struct ws2401, panel, &ws2401_drm_funcs,
                                  DRM_MODE_CONNECTOR_DPI);
        if (IS_ERR(ws))
                return PTR_ERR(ws);

        ws->dev = dev;

        /*
         * VCI   is the analog voltage supply
         * VCCIO is the digital I/O voltage supply
         */
        ws->regulators[0].supply = "vci";
        ws->regulators[1].supply = "vccio";
        ret = devm_regulator_bulk_get(dev,
                                      ARRAY_SIZE(ws->regulators),
                                      ws->regulators);
        if (ret)
                return dev_err_probe(dev, ret, "failed to get regulators\n");

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

        ret = mipi_dbi_spi_init(spi, &ws->dbi, NULL);
        if (ret)
                return dev_err_probe(dev, ret, "MIPI DBI init failed\n");
        ws->dbi.read_commands = ws2401_dbi_read_commands;

        ws2401_power_on(ws);
        ws2401_read_mtp_id(ws);
        ws2401_power_off(ws);

        ret = drm_panel_of_backlight(&ws->panel);
        if (ret)
                return dev_err_probe(dev, ret,
                                "failed to get external backlight device\n");

        if (!ws->panel.backlight) {
                dev_dbg(dev, "no external backlight, using internal backlight\n");
                ws->panel.backlight =
                        devm_backlight_device_register(dev, "ws2401", dev, ws,
                                &ws2401_bl_ops, &ws2401_bl_props);
                if (IS_ERR(ws->panel.backlight))
                        return dev_err_probe(dev, PTR_ERR(ws->panel.backlight),
                                "failed to register backlight device\n");
        } else {
                dev_dbg(dev, "using external backlight\n");
        }

        spi_set_drvdata(spi, ws);

        drm_panel_add(&ws->panel);
        dev_dbg(dev, "added panel\n");

        return 0;
}

static void ws2401_remove(struct spi_device *spi)
{
        struct ws2401 *ws = spi_get_drvdata(spi);

        drm_panel_remove(&ws->panel);
}

/*
 * Samsung LMS380KF01 is the one instance of this display controller that we
 * know about, but if more are found, the controller can be parameterized
 * here and used for other configurations.
 */
static const struct of_device_id ws2401_match[] = {
        { .compatible = "samsung,lms380kf01", },
        {},
};
MODULE_DEVICE_TABLE(of, ws2401_match);

static const struct spi_device_id ws2401_ids[] = {
        { "lms380kf01" },
        { },
};
MODULE_DEVICE_TABLE(spi, ws2401_ids);

static struct spi_driver ws2401_driver = {
        .probe          = ws2401_probe,
        .remove         = ws2401_remove,
        .id_table       = ws2401_ids,
        .driver         = {
                .name   = "ws2401-panel",
                .of_match_table = ws2401_match,
        },
};
module_spi_driver(ws2401_driver);

MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("Samsung WS2401 panel driver");
MODULE_LICENSE("GPL v2");