root/drivers/gpu/drm/panel/panel-innolux-ej030na.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Innolux/Chimei EJ030NA TFT LCD panel driver
 *
 * Copyright (C) 2020, Paul Cercueil <paul@crapouillou.net>
 * Copyright (C) 2020, Christophe Branchereau <cbranchereau@gmail.com>
 */

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>

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

struct ej030na_info {
        const struct drm_display_mode *display_modes;
        unsigned int num_modes;
        u16 width_mm, height_mm;
        u32 bus_format, bus_flags;
};

struct ej030na {
        struct drm_panel panel;
        struct spi_device *spi;
        struct regmap *map;

        const struct ej030na_info *panel_info;

        struct regulator *supply;
        struct gpio_desc *reset_gpio;
};

static inline struct ej030na *to_ej030na(struct drm_panel *panel)
{
        return container_of(panel, struct ej030na, panel);
}

static const struct reg_sequence ej030na_init_sequence[] = {
        { 0x05, 0x1e },
        { 0x05, 0x5c },
        { 0x02, 0x14 },
        { 0x03, 0x40 },
        { 0x04, 0x07 },
        { 0x06, 0x12 },
        { 0x07, 0xd2 },
        { 0x0c, 0x06 },
        { 0x0d, 0x40 },
        { 0x0e, 0x40 },
        { 0x0f, 0x40 },
        { 0x10, 0x40 },
        { 0x11, 0x40 },
        { 0x2f, 0x40 },
        { 0x5a, 0x02 },

        { 0x30, 0x07 },
        { 0x31, 0x57 },
        { 0x32, 0x53 },
        { 0x33, 0x77 },
        { 0x34, 0xb8 },
        { 0x35, 0xbd },
        { 0x36, 0xb8 },
        { 0x37, 0xe7 },
        { 0x38, 0x04 },
        { 0x39, 0xff },

        { 0x40, 0x0b },
        { 0x41, 0xb8 },
        { 0x42, 0xab },
        { 0x43, 0xb9 },
        { 0x44, 0x6a },
        { 0x45, 0x56 },
        { 0x46, 0x61 },
        { 0x47, 0x08 },
        { 0x48, 0x0f },
        { 0x49, 0x0f },
};

static int ej030na_prepare(struct drm_panel *panel)
{
        struct ej030na *priv = to_ej030na(panel);
        struct device *dev = &priv->spi->dev;
        int err;

        err = regulator_enable(priv->supply);
        if (err) {
                dev_err(dev, "Failed to enable power supply: %d\n", err);
                return err;
        }

        /* Reset the chip */
        gpiod_set_value_cansleep(priv->reset_gpio, 1);
        usleep_range(50, 150);
        gpiod_set_value_cansleep(priv->reset_gpio, 0);
        usleep_range(50, 150);

        err = regmap_multi_reg_write(priv->map, ej030na_init_sequence,
                                     ARRAY_SIZE(ej030na_init_sequence));
        if (err) {
                dev_err(dev, "Failed to init registers: %d\n", err);
                goto err_disable_regulator;
        }

        return 0;

err_disable_regulator:
        regulator_disable(priv->supply);
        return err;
}

static int ej030na_unprepare(struct drm_panel *panel)
{
        struct ej030na *priv = to_ej030na(panel);

        gpiod_set_value_cansleep(priv->reset_gpio, 1);
        regulator_disable(priv->supply);

        return 0;
}

static int ej030na_enable(struct drm_panel *panel)
{
        struct ej030na *priv = to_ej030na(panel);

        /* standby off */
        regmap_write(priv->map, 0x2b, 0x01);

        if (panel->backlight) {
                /* Wait for the picture to be ready before enabling backlight */
                msleep(120);
        }

        return 0;
}

static int ej030na_disable(struct drm_panel *panel)
{
        struct ej030na *priv = to_ej030na(panel);

        /* standby on */
        regmap_write(priv->map, 0x2b, 0x00);

        return 0;
}

static int ej030na_get_modes(struct drm_panel *panel,
                             struct drm_connector *connector)
{
        struct ej030na *priv = to_ej030na(panel);
        const struct ej030na_info *panel_info = priv->panel_info;
        struct drm_display_mode *mode;
        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);

                mode->type = DRM_MODE_TYPE_DRIVER;
                if (panel_info->num_modes == 1)
                        mode->type |= DRM_MODE_TYPE_PREFERRED;

                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;

        drm_display_info_set_bus_formats(&connector->display_info,
                                         &panel_info->bus_format, 1);
        connector->display_info.bus_flags = panel_info->bus_flags;

        return panel_info->num_modes;
}

static const struct drm_panel_funcs ej030na_funcs = {
        .prepare        = ej030na_prepare,
        .unprepare      = ej030na_unprepare,
        .enable         = ej030na_enable,
        .disable        = ej030na_disable,
        .get_modes      = ej030na_get_modes,
};

static const struct regmap_config ej030na_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0x5a,
};

static int ej030na_probe(struct spi_device *spi)
{
        struct device *dev = &spi->dev;
        struct ej030na *priv;
        int err;

        priv = devm_drm_panel_alloc(dev, struct ej030na, panel,
                                    &ej030na_funcs,
                                    DRM_MODE_CONNECTOR_DPI);
        if (IS_ERR(priv))
                return PTR_ERR(priv);

        priv->spi = spi;
        spi_set_drvdata(spi, priv);

        priv->map = devm_regmap_init_spi(spi, &ej030na_regmap_config);
        if (IS_ERR(priv->map)) {
                dev_err(dev, "Unable to init regmap\n");
                return PTR_ERR(priv->map);
        }

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

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

        priv->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(priv->reset_gpio))
                return dev_err_probe(dev, PTR_ERR(priv->reset_gpio),
                                     "Failed to get reset GPIO\n");

        err = drm_panel_of_backlight(&priv->panel);
        if (err)
                return err;

        drm_panel_add(&priv->panel);

        return 0;
}

static void ej030na_remove(struct spi_device *spi)
{
        struct ej030na *priv = spi_get_drvdata(spi);

        drm_panel_remove(&priv->panel);
        drm_panel_disable(&priv->panel);
        drm_panel_unprepare(&priv->panel);
}

static const struct drm_display_mode ej030na_modes[] = {
        { /* 60 Hz */
                .clock = 14400,
                .hdisplay = 320,
                .hsync_start = 320 + 10,
                .hsync_end = 320 + 10 + 37,
                .htotal = 320 + 10 + 37 + 33,
                .vdisplay = 480,
                .vsync_start = 480 + 102,
                .vsync_end = 480 + 102 + 9 + 9,
                .vtotal = 480 + 102 + 9 + 9,
                .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
        },
        { /* 50 Hz */
                .clock = 12000,
                .hdisplay = 320,
                .hsync_start = 320 + 10,
                .hsync_end = 320 + 10 + 37,
                .htotal = 320 + 10 + 37 + 33,
                .vdisplay = 480,
                .vsync_start = 480 + 102,
                .vsync_end = 480 + 102 + 9,
                .vtotal = 480 + 102 + 9 + 9,
                .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
        },
};

static const struct ej030na_info ej030na_info = {
        .display_modes = ej030na_modes,
        .num_modes = ARRAY_SIZE(ej030na_modes),
        .width_mm = 70,
        .height_mm = 51,
        .bus_format = MEDIA_BUS_FMT_RGB888_3X8_DELTA,
        .bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE | DRM_BUS_FLAG_DE_LOW,
};

static const struct of_device_id ej030na_of_match[] = {
        { .compatible = "innolux,ej030na", .data = &ej030na_info },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ej030na_of_match);

static struct spi_driver ej030na_driver = {
        .driver = {
                .name = "panel-innolux-ej030na",
                .of_match_table = ej030na_of_match,
        },
        .probe = ej030na_probe,
        .remove = ej030na_remove,
};
module_spi_driver(ej030na_driver);

MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
MODULE_AUTHOR("Christophe Branchereau <cbranchereau@gmail.com>");
MODULE_DESCRIPTION("Innolux/Chimei EJ030NA TFT LCD panel driver");
MODULE_LICENSE("GPL v2");