// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2014 Google, Inc.
 *
 * Copyright (C) 2022 Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
 *
 * Adapted from the downstream Pixel C driver written by Sean Paul
 */

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

#define MCS_CMD_ACS_PROT                        0xB0
#define MCS_CMD_ACS_PROT_OFF                    (0 << 0)

#define MCS_PWR_CTRL_FUNC                       0xD0
#define MCS_PWR_CTRL_PARAM1_DEFAULT             (2 << 0)
#define MCS_PWR_CTRL_PARAM1_VGH_210_DIV         (1 << 4)
#define MCS_PWR_CTRL_PARAM1_VGH_240_DIV         (2 << 4)
#define MCS_PWR_CTRL_PARAM1_VGH_280_DIV         (3 << 4)
#define MCS_PWR_CTRL_PARAM1_VGH_330_DIV         (4 << 4)
#define MCS_PWR_CTRL_PARAM1_VGH_410_DIV         (5 << 4)
#define MCS_PWR_CTRL_PARAM2_DEFAULT             (9 << 4)
#define MCS_PWR_CTRL_PARAM2_VGL_210_DIV         (1 << 0)
#define MCS_PWR_CTRL_PARAM2_VGL_240_DIV         (2 << 0)
#define MCS_PWR_CTRL_PARAM2_VGL_280_DIV         (3 << 0)
#define MCS_PWR_CTRL_PARAM2_VGL_330_DIV         (4 << 0)
#define MCS_PWR_CTRL_PARAM2_VGL_410_DIV         (5 << 0)

struct jdi_panel {
        struct drm_panel base;
        struct mipi_dsi_device *link1;
        struct mipi_dsi_device *link2;

        struct regulator *supply;
        struct regulator *ddi_supply;
        struct backlight_device *backlight;

        struct gpio_desc *enable_gpio;
        struct gpio_desc *reset_gpio;

        const struct drm_display_mode *mode;
};

static inline struct jdi_panel *to_panel_jdi(struct drm_panel *panel)
{
        return container_of(panel, struct jdi_panel, base);
}

static void jdi_wait_frames(struct jdi_panel *jdi, unsigned int frames)
{
        unsigned int refresh = drm_mode_vrefresh(jdi->mode);

        if (WARN_ON(frames > refresh))
                return;

        msleep(1000 / (refresh / frames));
}

static int jdi_panel_disable(struct drm_panel *panel)
{
        struct jdi_panel *jdi = to_panel_jdi(panel);

        backlight_disable(jdi->backlight);

        jdi_wait_frames(jdi, 2);

        return 0;
}

static int jdi_panel_unprepare(struct drm_panel *panel)
{
        struct jdi_panel *jdi = to_panel_jdi(panel);

        /*
         * One context per panel since we'll continue trying to shut down the
         * other panel even if one isn't responding.
         */
        struct mipi_dsi_multi_context dsi_ctx1 = { .dsi = jdi->link1 };
        struct mipi_dsi_multi_context dsi_ctx2 = { .dsi = jdi->link2 };

        mipi_dsi_dcs_set_display_off_multi(&dsi_ctx1);
        mipi_dsi_dcs_set_display_off_multi(&dsi_ctx2);

        /* Specified by JDI @ 50ms, subject to change */
        msleep(50);

        /* Doesn't hurt to try sleep mode even if display off fails */
        dsi_ctx1.accum_err = 0;
        dsi_ctx2.accum_err = 0;
        mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx1);
        mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx2);

        /* Specified by JDI @ 150ms, subject to change */
        msleep(150);

        gpiod_set_value(jdi->reset_gpio, 1);

        /* T4 = 1ms */
        usleep_range(1000, 3000);

        gpiod_set_value(jdi->enable_gpio, 0);

        /* T5 = 2ms */
        usleep_range(2000, 4000);

        regulator_disable(jdi->ddi_supply);

        /* T6 = 2ms plus some time to discharge capacitors */
        usleep_range(7000, 9000);

        regulator_disable(jdi->supply);
        /* Specified by JDI @ 20ms, subject to change */
        msleep(20);

        return 0;
}

static void jdi_setup_symmetrical_split(struct mipi_dsi_multi_context *dsi_ctx,
                                        struct mipi_dsi_device *left,
                                        struct mipi_dsi_device *right,
                                        const struct drm_display_mode *mode)
{
        mipi_dsi_dual(mipi_dsi_dcs_set_column_address_multi,
                      dsi_ctx, left, right,
                      0, mode->hdisplay / 2 - 1);
        mipi_dsi_dual(mipi_dsi_dcs_set_page_address_multi,
                      dsi_ctx, left, right,
                      0, mode->vdisplay - 1);
}

static void jdi_write_dcdc_registers(struct mipi_dsi_multi_context *dsi_ctx,
                                     struct jdi_panel *jdi)
{
        /* Clear the manufacturer command access protection */
        mipi_dsi_dual_generic_write_seq_multi(dsi_ctx, jdi->link1, jdi->link2,
                                              MCS_CMD_ACS_PROT,
                                              MCS_CMD_ACS_PROT_OFF);
        /*
         * Change the VGH/VGL divide ratios to move the noise generated by the
         * TCONN. This should hopefully avoid interaction with the backlight
         * controller.
         */
        mipi_dsi_dual_generic_write_seq_multi(dsi_ctx, jdi->link1, jdi->link2,
                                              MCS_PWR_CTRL_FUNC,
                                              MCS_PWR_CTRL_PARAM1_VGH_330_DIV |
                                              MCS_PWR_CTRL_PARAM1_DEFAULT,
                                              MCS_PWR_CTRL_PARAM2_VGL_410_DIV |
                                              MCS_PWR_CTRL_PARAM2_DEFAULT);
}

static int jdi_panel_prepare(struct drm_panel *panel)
{
        struct jdi_panel *jdi = to_panel_jdi(panel);
        struct mipi_dsi_multi_context dsi_ctx = {};
        int err;

        /* Disable backlight to avoid showing random pixels
         * with a conservative delay for it to take effect.
         */
        backlight_disable(jdi->backlight);
        jdi_wait_frames(jdi, 3);

        jdi->link1->mode_flags |= MIPI_DSI_MODE_LPM;
        jdi->link2->mode_flags |= MIPI_DSI_MODE_LPM;

        err = regulator_enable(jdi->supply);
        if (err < 0) {
                dev_err(panel->dev, "failed to enable supply: %d\n", err);
                return err;
        }
        /* T1 = 2ms */
        usleep_range(2000, 4000);

        err = regulator_enable(jdi->ddi_supply);
        if (err < 0) {
                dev_err(panel->dev, "failed to enable ddi_supply: %d\n", err);
                goto supply_off;
        }
        /* T2 = 1ms */
        usleep_range(1000, 3000);

        gpiod_set_value(jdi->enable_gpio, 1);
        /* T3 = 10ms */
        usleep_range(10000, 15000);

        gpiod_set_value(jdi->reset_gpio, 0);
        /* Specified by JDI @ 3ms, subject to change */
        usleep_range(3000, 5000);

        /*
         * TODO: The device supports both left-right and even-odd split
         * configurations, but this driver currently supports only the left-
         * right split. To support a different mode a mechanism needs to be
         * put in place to communicate the configuration back to the DSI host
         * controller.
         */
        jdi_setup_symmetrical_split(&dsi_ctx, jdi->link1, jdi->link2,
                                    jdi->mode);

        mipi_dsi_dual(mipi_dsi_dcs_set_tear_scanline_multi,
                      &dsi_ctx, jdi->link1, jdi->link2,
                      jdi->mode->vdisplay - 16);

        mipi_dsi_dual(mipi_dsi_dcs_set_tear_on_multi,
                      &dsi_ctx, jdi->link1, jdi->link2,
                      MIPI_DSI_DCS_TEAR_MODE_VBLANK);

        mipi_dsi_dual(mipi_dsi_dcs_set_pixel_format_multi,
                      &dsi_ctx, jdi->link1, jdi->link2,
                      MIPI_DCS_PIXEL_FMT_24BIT);

        mipi_dsi_dual(mipi_dsi_dcs_exit_sleep_mode_multi,
                      &dsi_ctx, jdi->link1, jdi->link2);

        jdi_write_dcdc_registers(&dsi_ctx, jdi);
        /*
         * We need to wait 150ms between mipi_dsi_dcs_exit_sleep_mode_multi()
         * and mipi_dsi_dcs_set_display_on_multi().
         */
        mipi_dsi_msleep(&dsi_ctx, 150);

        mipi_dsi_dual(mipi_dsi_dcs_set_display_on_multi,
                      &dsi_ctx, jdi->link1, jdi->link2);

        if (dsi_ctx.accum_err < 0) {
                err = dsi_ctx.accum_err;
                goto poweroff;
        }

        jdi->link1->mode_flags &= ~MIPI_DSI_MODE_LPM;
        jdi->link2->mode_flags &= ~MIPI_DSI_MODE_LPM;

        return 0;

poweroff:
        regulator_disable(jdi->ddi_supply);

        /* T6 = 2ms plus some time to discharge capacitors */
        usleep_range(7000, 9000);
supply_off:
        regulator_disable(jdi->supply);
        /* Specified by JDI @ 20ms, subject to change */
        msleep(20);

        return err;
}

static int jdi_panel_enable(struct drm_panel *panel)
{
        struct jdi_panel *jdi = to_panel_jdi(panel);

        /*
         * Ensure we send image data before turning the backlight
         * on, to avoid the display showing random pixels.
         */
        jdi_wait_frames(jdi, 3);

        backlight_enable(jdi->backlight);

        return 0;
}

static const struct drm_display_mode default_mode = {
        .clock = (2560 + 80 + 80 + 80) * (1800 + 4 + 4 + 4) * 60 / 1000,
        .hdisplay = 2560,
        .hsync_start = 2560 + 80,
        .hsync_end = 2560 + 80 + 80,
        .htotal = 2560 + 80 + 80 + 80,
        .vdisplay = 1800,
        .vsync_start = 1800 + 4,
        .vsync_end = 1800 + 4 + 4,
        .vtotal = 1800 + 4 + 4 + 4,
        .flags = 0,
};

static int jdi_panel_get_modes(struct drm_panel *panel,
                               struct drm_connector *connector)
{
        struct drm_display_mode *mode;
        struct jdi_panel *jdi = to_panel_jdi(panel);
        struct device *dev = &jdi->link1->dev;

        mode = drm_mode_duplicate(connector->dev, &default_mode);
        if (!mode) {
                dev_err(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 = 211;
        connector->display_info.height_mm = 148;
        connector->display_info.bpc = 8;

        return 1;
}

static const struct drm_panel_funcs jdi_panel_funcs = {
        .prepare = jdi_panel_prepare,
        .enable = jdi_panel_enable,
        .disable = jdi_panel_disable,
        .unprepare = jdi_panel_unprepare,
        .get_modes = jdi_panel_get_modes,
};

static const struct of_device_id jdi_of_match[] = {
        { .compatible = "jdi,lpm102a188a", },
        { }
};
MODULE_DEVICE_TABLE(of, jdi_of_match);

static int jdi_panel_add(struct jdi_panel *jdi)
{
        struct device *dev = &jdi->link1->dev;

        jdi->mode = &default_mode;

        jdi->supply = devm_regulator_get(dev, "power");
        if (IS_ERR(jdi->supply))
                return dev_err_probe(dev, PTR_ERR(jdi->supply),
                                     "failed to get power regulator\n");

        jdi->ddi_supply = devm_regulator_get(dev, "ddi");
        if (IS_ERR(jdi->ddi_supply))
                return dev_err_probe(dev, PTR_ERR(jdi->ddi_supply),
                                     "failed to get ddi regulator\n");

        jdi->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(jdi->reset_gpio))
                return dev_err_probe(dev, PTR_ERR(jdi->reset_gpio),
                                     "failed to get reset gpio\n");
        /* T4 = 1ms */
        usleep_range(1000, 3000);

        jdi->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
        if (IS_ERR(jdi->enable_gpio))
                return dev_err_probe(dev, PTR_ERR(jdi->enable_gpio),
                                     "failed to get enable gpio\n");
        /* T5 = 2ms */
        usleep_range(2000, 4000);

        jdi->backlight = devm_of_find_backlight(dev);
        if (IS_ERR(jdi->backlight))
                return dev_err_probe(dev, PTR_ERR(jdi->backlight),
                                     "failed to create backlight\n");

        drm_panel_add(&jdi->base);

        return 0;
}

static void jdi_panel_del(struct jdi_panel *jdi)
{
        if (jdi->base.dev)
                drm_panel_remove(&jdi->base);

        if (jdi->link2)
                put_device(&jdi->link2->dev);
}

static int jdi_panel_dsi_probe(struct mipi_dsi_device *dsi)
{
        struct mipi_dsi_device *secondary = NULL;
        struct jdi_panel *jdi;
        struct device_node *np;
        int err;

        dsi->lanes = 4;
        dsi->format = MIPI_DSI_FMT_RGB888;
        dsi->mode_flags = 0;

        /* Find DSI-LINK1 */
        np = of_parse_phandle(dsi->dev.of_node, "link2", 0);
        if (np) {
                secondary = of_find_mipi_dsi_device_by_node(np);
                of_node_put(np);

                if (!secondary)
                        return -EPROBE_DEFER;
        }

        /* register a panel for only the DSI-LINK1 interface */
        if (secondary) {
                jdi = devm_drm_panel_alloc(&dsi->dev, __typeof(*jdi),
                                           base, &jdi_panel_funcs,
                                           DRM_MODE_CONNECTOR_DSI);

                if (IS_ERR(jdi)) {
                        put_device(&secondary->dev);
                        return PTR_ERR(jdi);
                }

                mipi_dsi_set_drvdata(dsi, jdi);

                jdi->link1 = dsi;
                jdi->link2 = secondary;

                err = jdi_panel_add(jdi);
                if (err < 0) {
                        put_device(&secondary->dev);
                        return err;
                }
        }

        err = mipi_dsi_attach(dsi);
        if (err < 0) {
                if (secondary)
                        jdi_panel_del(jdi);

                return err;
        }

        return 0;
}

static void jdi_panel_dsi_remove(struct mipi_dsi_device *dsi)
{
        struct jdi_panel *jdi = mipi_dsi_get_drvdata(dsi);
        int err;

        /* only detach from host for the DSI-LINK2 interface */
        if (!jdi) {
                mipi_dsi_detach(dsi);
                return;
        }

        err = jdi_panel_disable(&jdi->base);
        if (err < 0)
                dev_err(&dsi->dev, "failed to disable panel: %d\n", err);

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

        jdi_panel_del(jdi);
}

static void jdi_panel_dsi_shutdown(struct mipi_dsi_device *dsi)
{
        struct jdi_panel *jdi = mipi_dsi_get_drvdata(dsi);

        if (!jdi)
                return;

        jdi_panel_disable(&jdi->base);
}

static struct mipi_dsi_driver jdi_panel_dsi_driver = {
        .driver = {
                .name = "panel-jdi-lpm102a188a",
                .of_match_table = jdi_of_match,
        },
        .probe = jdi_panel_dsi_probe,
        .remove = jdi_panel_dsi_remove,
        .shutdown = jdi_panel_dsi_shutdown,
};
module_mipi_dsi_driver(jdi_panel_dsi_driver);

MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
MODULE_AUTHOR("Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>");
MODULE_DESCRIPTION("DRM Driver for JDI LPM102A188A DSI panel, command mode");
MODULE_LICENSE("GPL");