// SPDX-License-Identifier: GPL-2.0+
/*
 * MIPI-DSI Samsung s6d16d0 panel driver. This is a 864x480
 * AMOLED panel with a command-only DSI interface.
 */

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

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

struct s6d16d0 {
        struct device *dev;
        struct drm_panel panel;
        struct regulator *supply;
        struct gpio_desc *reset_gpio;
};

/*
 * The timings are not very helpful as the display is used in
 * command mode.
 */
static const struct drm_display_mode samsung_s6d16d0_mode = {
        /* HS clock, (htotal*vtotal*vrefresh)/1000 */
        .clock = 420160,
        .hdisplay = 864,
        .hsync_start = 864 + 154,
        .hsync_end = 864 + 154 + 16,
        .htotal = 864 + 154 + 16 + 32,
        .vdisplay = 480,
        .vsync_start = 480 + 1,
        .vsync_end = 480 + 1 + 1,
        .vtotal = 480 + 1 + 1 + 1,
        .width_mm = 84,
        .height_mm = 48,
};

static inline struct s6d16d0 *panel_to_s6d16d0(struct drm_panel *panel)
{
        return container_of(panel, struct s6d16d0, panel);
}

static int s6d16d0_unprepare(struct drm_panel *panel)
{
        struct s6d16d0 *s6 = panel_to_s6d16d0(panel);
        struct mipi_dsi_device *dsi = to_mipi_dsi_device(s6->dev);
        int ret;

        /* Enter sleep mode */
        ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
        if (ret) {
                dev_err(s6->dev, "failed to enter sleep mode (%d)\n", ret);
                return ret;
        }

        /* Assert RESET */
        gpiod_set_value_cansleep(s6->reset_gpio, 1);
        regulator_disable(s6->supply);

        return 0;
}

static int s6d16d0_prepare(struct drm_panel *panel)
{
        struct s6d16d0 *s6 = panel_to_s6d16d0(panel);
        struct mipi_dsi_device *dsi = to_mipi_dsi_device(s6->dev);
        int ret;

        ret = regulator_enable(s6->supply);
        if (ret) {
                dev_err(s6->dev, "failed to enable supply (%d)\n", ret);
                return ret;
        }

        /* Assert RESET */
        gpiod_set_value_cansleep(s6->reset_gpio, 1);
        udelay(10);
        /* De-assert RESET */
        gpiod_set_value_cansleep(s6->reset_gpio, 0);
        msleep(120);

        /* Enabe tearing mode: send TE (tearing effect) at VBLANK */
        ret = mipi_dsi_dcs_set_tear_on(dsi,
                                       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
        if (ret) {
                dev_err(s6->dev, "failed to enable vblank TE (%d)\n", ret);
                return ret;
        }
        /* Exit sleep mode and power on */
        ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
        if (ret) {
                dev_err(s6->dev, "failed to exit sleep mode (%d)\n", ret);
                return ret;
        }

        return 0;
}

static int s6d16d0_enable(struct drm_panel *panel)
{
        struct s6d16d0 *s6 = panel_to_s6d16d0(panel);
        struct mipi_dsi_device *dsi = to_mipi_dsi_device(s6->dev);
        int ret;

        ret = mipi_dsi_dcs_set_display_on(dsi);
        if (ret) {
                dev_err(s6->dev, "failed to turn display on (%d)\n", ret);
                return ret;
        }

        return 0;
}

static int s6d16d0_disable(struct drm_panel *panel)
{
        struct s6d16d0 *s6 = panel_to_s6d16d0(panel);
        struct mipi_dsi_device *dsi = to_mipi_dsi_device(s6->dev);
        int ret;

        ret = mipi_dsi_dcs_set_display_off(dsi);
        if (ret) {
                dev_err(s6->dev, "failed to turn display off (%d)\n", ret);
                return ret;
        }

        return 0;
}

static int s6d16d0_get_modes(struct drm_panel *panel,
                             struct drm_connector *connector)
{
        struct drm_display_mode *mode;

        mode = drm_mode_duplicate(connector->dev, &samsung_s6d16d0_mode);
        if (!mode) {
                dev_err(panel->dev, "bad mode or failed to add mode\n");
                return -EINVAL;
        }
        drm_mode_set_name(mode);
        mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;

        connector->display_info.width_mm = mode->width_mm;
        connector->display_info.height_mm = mode->height_mm;

        drm_mode_probed_add(connector, mode);

        return 1; /* Number of modes */
}

static const struct drm_panel_funcs s6d16d0_drm_funcs = {
        .disable = s6d16d0_disable,
        .unprepare = s6d16d0_unprepare,
        .prepare = s6d16d0_prepare,
        .enable = s6d16d0_enable,
        .get_modes = s6d16d0_get_modes,
};

static int s6d16d0_probe(struct mipi_dsi_device *dsi)
{
        struct device *dev = &dsi->dev;
        struct s6d16d0 *s6;
        int ret;

        s6 = devm_drm_panel_alloc(dev, struct s6d16d0, panel,
                                  &s6d16d0_drm_funcs,
                                  DRM_MODE_CONNECTOR_DSI);
        if (IS_ERR(s6))
                return PTR_ERR(s6);

        mipi_dsi_set_drvdata(dsi, s6);
        s6->dev = dev;

        dsi->lanes = 2;
        dsi->format = MIPI_DSI_FMT_RGB888;
        dsi->hs_rate = 420160000;
        dsi->lp_rate = 19200000;
        /*
         * This display uses command mode so no MIPI_DSI_MODE_VIDEO
         * or MIPI_DSI_MODE_VIDEO_SYNC_PULSE
         *
         * As we only send commands we do not need to be continuously
         * clocked.
         */
        dsi->mode_flags = MIPI_DSI_CLOCK_NON_CONTINUOUS;

        s6->supply = devm_regulator_get(dev, "vdd1");
        if (IS_ERR(s6->supply))
                return PTR_ERR(s6->supply);

        /* This asserts RESET by default */
        s6->reset_gpio = devm_gpiod_get_optional(dev, "reset",
                                                 GPIOD_OUT_HIGH);
        if (IS_ERR(s6->reset_gpio)) {
                ret = PTR_ERR(s6->reset_gpio);
                if (ret != -EPROBE_DEFER)
                        dev_err(dev, "failed to request GPIO (%d)\n", ret);
                return ret;
        }

        drm_panel_add(&s6->panel);

        ret = mipi_dsi_attach(dsi);
        if (ret < 0)
                drm_panel_remove(&s6->panel);

        return ret;
}

static void s6d16d0_remove(struct mipi_dsi_device *dsi)
{
        struct s6d16d0 *s6 = mipi_dsi_get_drvdata(dsi);

        mipi_dsi_detach(dsi);
        drm_panel_remove(&s6->panel);
}

static const struct of_device_id s6d16d0_of_match[] = {
        { .compatible = "samsung,s6d16d0" },
        { }
};
MODULE_DEVICE_TABLE(of, s6d16d0_of_match);

static struct mipi_dsi_driver s6d16d0_driver = {
        .probe = s6d16d0_probe,
        .remove = s6d16d0_remove,
        .driver = {
                .name = "panel-samsung-s6d16d0",
                .of_match_table = s6d16d0_of_match,
        },
};
module_mipi_dsi_driver(s6d16d0_driver);

MODULE_AUTHOR("Linus Wallei <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("MIPI-DSI s6d16d0 Panel Driver");
MODULE_LICENSE("GPL v2");