root/drivers/gpu/drm/sitronix/st7735r.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * DRM driver for display panels connected to a Sitronix ST7715R or ST7735R
 * display controller in SPI mode.
 *
 * Copyright 2017 David Lechner <david@lechnology.com>
 * Copyright (C) 2019 Glider bvba
 */

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/dma-buf.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/spi/spi.h>
#include <video/mipi_display.h>

#include <drm/clients/drm_client_setup.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_mipi_dbi.h>
#include <drm/drm_print.h>

#define ST7735R_FRMCTR1         0xb1
#define ST7735R_FRMCTR2         0xb2
#define ST7735R_FRMCTR3         0xb3
#define ST7735R_INVCTR          0xb4
#define ST7735R_PWCTR1          0xc0
#define ST7735R_PWCTR2          0xc1
#define ST7735R_PWCTR3          0xc2
#define ST7735R_PWCTR4          0xc3
#define ST7735R_PWCTR5          0xc4
#define ST7735R_VMCTR1          0xc5
#define ST7735R_GAMCTRP1        0xe0
#define ST7735R_GAMCTRN1        0xe1

#define ST7735R_MY      BIT(7)
#define ST7735R_MX      BIT(6)
#define ST7735R_MV      BIT(5)
#define ST7735R_RGB     BIT(3)

struct st7735r_cfg {
        const struct drm_display_mode mode;
        unsigned int left_offset;
        unsigned int top_offset;
        unsigned int write_only:1;
        unsigned int rgb:1;             /* RGB (vs. BGR) */
};

struct st7735r_priv {
        struct mipi_dbi_dev dbidev;     /* Must be first for .release() */
        const struct st7735r_cfg *cfg;
};

static void st7735r_pipe_enable(struct drm_simple_display_pipe *pipe,
                                struct drm_crtc_state *crtc_state,
                                struct drm_plane_state *plane_state)
{
        struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
        struct st7735r_priv *priv = container_of(dbidev, struct st7735r_priv,
                                                 dbidev);
        struct mipi_dbi *dbi = &dbidev->dbi;
        int ret, idx;
        u8 addr_mode;

        if (!drm_dev_enter(pipe->crtc.dev, &idx))
                return;

        DRM_DEBUG_KMS("\n");

        ret = mipi_dbi_poweron_reset(dbidev);
        if (ret)
                goto out_exit;

        msleep(150);

        mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
        msleep(500);

        mipi_dbi_command(dbi, ST7735R_FRMCTR1, 0x01, 0x2c, 0x2d);
        mipi_dbi_command(dbi, ST7735R_FRMCTR2, 0x01, 0x2c, 0x2d);
        mipi_dbi_command(dbi, ST7735R_FRMCTR3, 0x01, 0x2c, 0x2d, 0x01, 0x2c,
                         0x2d);
        mipi_dbi_command(dbi, ST7735R_INVCTR, 0x07);
        mipi_dbi_command(dbi, ST7735R_PWCTR1, 0xa2, 0x02, 0x84);
        mipi_dbi_command(dbi, ST7735R_PWCTR2, 0xc5);
        mipi_dbi_command(dbi, ST7735R_PWCTR3, 0x0a, 0x00);
        mipi_dbi_command(dbi, ST7735R_PWCTR4, 0x8a, 0x2a);
        mipi_dbi_command(dbi, ST7735R_PWCTR5, 0x8a, 0xee);
        mipi_dbi_command(dbi, ST7735R_VMCTR1, 0x0e);
        mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
        switch (dbidev->rotation) {
        default:
                addr_mode = ST7735R_MX | ST7735R_MY;
                break;
        case 90:
                addr_mode = ST7735R_MX | ST7735R_MV;
                break;
        case 180:
                addr_mode = 0;
                break;
        case 270:
                addr_mode = ST7735R_MY | ST7735R_MV;
                break;
        }

        if (priv->cfg->rgb)
                addr_mode |= ST7735R_RGB;

        mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
        mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT,
                         MIPI_DCS_PIXEL_FMT_16BIT);
        mipi_dbi_command(dbi, ST7735R_GAMCTRP1, 0x02, 0x1c, 0x07, 0x12, 0x37,
                         0x32, 0x29, 0x2d, 0x29, 0x25, 0x2b, 0x39, 0x00, 0x01,
                         0x03, 0x10);
        mipi_dbi_command(dbi, ST7735R_GAMCTRN1, 0x03, 0x1d, 0x07, 0x06, 0x2e,
                         0x2c, 0x29, 0x2d, 0x2e, 0x2e, 0x37, 0x3f, 0x00, 0x00,
                         0x02, 0x10);
        mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);

        msleep(100);

        mipi_dbi_command(dbi, MIPI_DCS_ENTER_NORMAL_MODE);

        msleep(20);

        mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
out_exit:
        drm_dev_exit(idx);
}

static const struct drm_simple_display_pipe_funcs st7735r_pipe_funcs = {
        DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(st7735r_pipe_enable),
};

static const struct st7735r_cfg jd_t18003_t01_cfg = {
        .mode           = { DRM_SIMPLE_MODE(128, 160, 28, 35) },
        /* Cannot read from Adafruit 1.8" display via SPI */
        .write_only     = true,
};

static const struct st7735r_cfg rh128128t_cfg = {
        .mode           = { DRM_SIMPLE_MODE(128, 128, 25, 26) },
        .left_offset    = 2,
        .top_offset     = 3,
        .rgb            = true,
};

DEFINE_DRM_GEM_DMA_FOPS(st7735r_fops);

static const struct drm_driver st7735r_driver = {
        .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
        .fops                   = &st7735r_fops,
        DRM_GEM_DMA_DRIVER_OPS_VMAP,
        DRM_FBDEV_DMA_DRIVER_OPS,
        .debugfs_init           = mipi_dbi_debugfs_init,
        .name                   = "st7735r",
        .desc                   = "Sitronix ST7735R",
        .major                  = 1,
        .minor                  = 0,
};

static const struct of_device_id st7735r_of_match[] = {
        { .compatible = "jianda,jd-t18003-t01", .data = &jd_t18003_t01_cfg },
        { .compatible = "okaya,rh128128t", .data = &rh128128t_cfg },
        { },
};
MODULE_DEVICE_TABLE(of, st7735r_of_match);

static const struct spi_device_id st7735r_id[] = {
        { "jd-t18003-t01", (uintptr_t)&jd_t18003_t01_cfg },
        { "rh128128t", (uintptr_t)&rh128128t_cfg },
        { },
};
MODULE_DEVICE_TABLE(spi, st7735r_id);

static int st7735r_probe(struct spi_device *spi)
{
        struct device *dev = &spi->dev;
        const struct st7735r_cfg *cfg;
        struct mipi_dbi_dev *dbidev;
        struct st7735r_priv *priv;
        struct drm_device *drm;
        struct mipi_dbi *dbi;
        struct gpio_desc *dc;
        u32 rotation = 0;
        int ret;

        cfg = device_get_match_data(&spi->dev);
        if (!cfg)
                cfg = (void *)spi_get_device_id(spi)->driver_data;

        priv = devm_drm_dev_alloc(dev, &st7735r_driver,
                                  struct st7735r_priv, dbidev.drm);
        if (IS_ERR(priv))
                return PTR_ERR(priv);

        dbidev = &priv->dbidev;
        priv->cfg = cfg;

        dbi = &dbidev->dbi;
        drm = &dbidev->drm;

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

        dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
        if (IS_ERR(dc))
                return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n");

        dbidev->backlight = devm_of_find_backlight(dev);
        if (IS_ERR(dbidev->backlight))
                return PTR_ERR(dbidev->backlight);

        device_property_read_u32(dev, "rotation", &rotation);

        ret = mipi_dbi_spi_init(spi, dbi, dc);
        if (ret)
                return ret;

        if (cfg->write_only)
                dbi->read_commands = NULL;

        dbidev->left_offset = cfg->left_offset;
        dbidev->top_offset = cfg->top_offset;

        ret = mipi_dbi_dev_init(dbidev, &st7735r_pipe_funcs, &cfg->mode,
                                rotation);
        if (ret)
                return ret;

        drm_mode_config_reset(drm);

        ret = drm_dev_register(drm, 0);
        if (ret)
                return ret;

        spi_set_drvdata(spi, drm);

        drm_client_setup(drm, NULL);

        return 0;
}

static void st7735r_remove(struct spi_device *spi)
{
        struct drm_device *drm = spi_get_drvdata(spi);

        drm_dev_unplug(drm);
        drm_atomic_helper_shutdown(drm);
}

static void st7735r_shutdown(struct spi_device *spi)
{
        drm_atomic_helper_shutdown(spi_get_drvdata(spi));
}

static struct spi_driver st7735r_spi_driver = {
        .driver = {
                .name = "st7735r",
                .of_match_table = st7735r_of_match,
        },
        .id_table = st7735r_id,
        .probe = st7735r_probe,
        .remove = st7735r_remove,
        .shutdown = st7735r_shutdown,
};
module_spi_driver(st7735r_spi_driver);

MODULE_DESCRIPTION("Sitronix ST7735R DRM driver");
MODULE_AUTHOR("David Lechner <david@lechnology.com>");
MODULE_LICENSE("GPL");