// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * DRM driver for Ilitek ILI9225 panels
 *
 * Copyright 2017 David Lechner <david@lechnology.com>
 *
 * Some code copied from mipi-dbi.c
 * Copyright 2016 Noralf Trønnes
 */

#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_damage_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_mipi_dbi.h>
#include <drm/drm_print.h>
#include <drm/drm_rect.h>

#define ILI9225_DRIVER_READ_CODE        0x00
#define ILI9225_DRIVER_OUTPUT_CONTROL   0x01
#define ILI9225_LCD_AC_DRIVING_CONTROL  0x02
#define ILI9225_ENTRY_MODE              0x03
#define ILI9225_DISPLAY_CONTROL_1       0x07
#define ILI9225_BLANK_PERIOD_CONTROL_1  0x08
#define ILI9225_FRAME_CYCLE_CONTROL     0x0b
#define ILI9225_INTERFACE_CONTROL       0x0c
#define ILI9225_OSCILLATION_CONTROL     0x0f
#define ILI9225_POWER_CONTROL_1         0x10
#define ILI9225_POWER_CONTROL_2         0x11
#define ILI9225_POWER_CONTROL_3         0x12
#define ILI9225_POWER_CONTROL_4         0x13
#define ILI9225_POWER_CONTROL_5         0x14
#define ILI9225_VCI_RECYCLING           0x15
#define ILI9225_RAM_ADDRESS_SET_1       0x20
#define ILI9225_RAM_ADDRESS_SET_2       0x21
#define ILI9225_WRITE_DATA_TO_GRAM      0x22
#define ILI9225_SOFTWARE_RESET          0x28
#define ILI9225_GATE_SCAN_CONTROL       0x30
#define ILI9225_VERTICAL_SCROLL_1       0x31
#define ILI9225_VERTICAL_SCROLL_2       0x32
#define ILI9225_VERTICAL_SCROLL_3       0x33
#define ILI9225_PARTIAL_DRIVING_POS_1   0x34
#define ILI9225_PARTIAL_DRIVING_POS_2   0x35
#define ILI9225_HORIZ_WINDOW_ADDR_1     0x36
#define ILI9225_HORIZ_WINDOW_ADDR_2     0x37
#define ILI9225_VERT_WINDOW_ADDR_1      0x38
#define ILI9225_VERT_WINDOW_ADDR_2      0x39
#define ILI9225_GAMMA_CONTROL_1         0x50
#define ILI9225_GAMMA_CONTROL_2         0x51
#define ILI9225_GAMMA_CONTROL_3         0x52
#define ILI9225_GAMMA_CONTROL_4         0x53
#define ILI9225_GAMMA_CONTROL_5         0x54
#define ILI9225_GAMMA_CONTROL_6         0x55
#define ILI9225_GAMMA_CONTROL_7         0x56
#define ILI9225_GAMMA_CONTROL_8         0x57
#define ILI9225_GAMMA_CONTROL_9         0x58
#define ILI9225_GAMMA_CONTROL_10        0x59

static inline int ili9225_command(struct mipi_dbi *dbi, u8 cmd, u16 data)
{
        u8 par[2] = { data >> 8, data & 0xff };

        return mipi_dbi_command_buf(dbi, cmd, par, 2);
}

static void ili9225_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
                             struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)
{
        struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
        unsigned int height = rect->y2 - rect->y1;
        unsigned int width = rect->x2 - rect->x1;
        struct mipi_dbi *dbi = &dbidev->dbi;
        bool swap = dbi->swap_bytes;
        u16 x_start, y_start;
        u16 x1, x2, y1, y2;
        int ret = 0;
        bool full;
        void *tr;

        full = width == fb->width && height == fb->height;

        DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));

        if (!dbi->dc || !full || swap ||
            fb->format->format == DRM_FORMAT_XRGB8888) {
                tr = dbidev->tx_buf;
                ret = mipi_dbi_buf_copy(tr, src, fb, rect, swap, fmtcnv_state);
                if (ret)
                        goto err_msg;
        } else {
                tr = src->vaddr; /* TODO: Use mapping abstraction properly */
        }

        switch (dbidev->rotation) {
        default:
                x1 = rect->x1;
                x2 = rect->x2 - 1;
                y1 = rect->y1;
                y2 = rect->y2 - 1;
                x_start = x1;
                y_start = y1;
                break;
        case 90:
                x1 = rect->y1;
                x2 = rect->y2 - 1;
                y1 = fb->width - rect->x2;
                y2 = fb->width - rect->x1 - 1;
                x_start = x1;
                y_start = y2;
                break;
        case 180:
                x1 = fb->width - rect->x2;
                x2 = fb->width - rect->x1 - 1;
                y1 = fb->height - rect->y2;
                y2 = fb->height - rect->y1 - 1;
                x_start = x2;
                y_start = y2;
                break;
        case 270:
                x1 = fb->height - rect->y2;
                x2 = fb->height - rect->y1 - 1;
                y1 = rect->x1;
                y2 = rect->x2 - 1;
                x_start = x2;
                y_start = y1;
                break;
        }

        ili9225_command(dbi, ILI9225_HORIZ_WINDOW_ADDR_1, x2);
        ili9225_command(dbi, ILI9225_HORIZ_WINDOW_ADDR_2, x1);
        ili9225_command(dbi, ILI9225_VERT_WINDOW_ADDR_1, y2);
        ili9225_command(dbi, ILI9225_VERT_WINDOW_ADDR_2, y1);

        ili9225_command(dbi, ILI9225_RAM_ADDRESS_SET_1, x_start);
        ili9225_command(dbi, ILI9225_RAM_ADDRESS_SET_2, y_start);

        ret = mipi_dbi_command_buf(dbi, ILI9225_WRITE_DATA_TO_GRAM, tr,
                                   width * height * 2);
err_msg:
        if (ret)
                dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
}

static void ili9225_pipe_update(struct drm_simple_display_pipe *pipe,
                                struct drm_plane_state *old_state)
{
        struct drm_plane_state *state = pipe->plane.state;
        struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
        struct drm_framebuffer *fb = state->fb;
        struct drm_rect rect;
        int idx;

        if (!pipe->crtc.state->active)
                return;

        if (!drm_dev_enter(fb->dev, &idx))
                return;

        if (drm_atomic_helper_damage_merged(old_state, state, &rect))
                ili9225_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
                                 &shadow_plane_state->fmtcnv_state);

        drm_dev_exit(idx);
}

static void ili9225_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 drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
        struct drm_framebuffer *fb = plane_state->fb;
        struct device *dev = pipe->crtc.dev->dev;
        struct mipi_dbi *dbi = &dbidev->dbi;
        struct drm_rect rect = {
                .x1 = 0,
                .x2 = fb->width,
                .y1 = 0,
                .y2 = fb->height,
        };
        int ret, idx;
        u8 am_id;

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

        DRM_DEBUG_KMS("\n");

        mipi_dbi_hw_reset(dbi);

        /*
         * There don't seem to be two example init sequences that match, so
         * using the one from the popular Arduino library for this display.
         * https://github.com/Nkawu/TFT_22_ILI9225/blob/master/src/TFT_22_ILI9225.cpp
         */

        ret = ili9225_command(dbi, ILI9225_POWER_CONTROL_1, 0x0000);
        if (ret) {
                DRM_DEV_ERROR(dev, "Error sending command %d\n", ret);
                goto out_exit;
        }
        ili9225_command(dbi, ILI9225_POWER_CONTROL_2, 0x0000);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_3, 0x0000);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_4, 0x0000);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_5, 0x0000);

        msleep(40);

        ili9225_command(dbi, ILI9225_POWER_CONTROL_2, 0x0018);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_3, 0x6121);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_4, 0x006f);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_5, 0x495f);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_1, 0x0800);

        msleep(10);

        ili9225_command(dbi, ILI9225_POWER_CONTROL_2, 0x103b);

        msleep(50);

        switch (dbidev->rotation) {
        default:
                am_id = 0x30;
                break;
        case 90:
                am_id = 0x18;
                break;
        case 180:
                am_id = 0x00;
                break;
        case 270:
                am_id = 0x28;
                break;
        }
        ili9225_command(dbi, ILI9225_DRIVER_OUTPUT_CONTROL, 0x011c);
        ili9225_command(dbi, ILI9225_LCD_AC_DRIVING_CONTROL, 0x0100);
        ili9225_command(dbi, ILI9225_ENTRY_MODE, 0x1000 | am_id);
        ili9225_command(dbi, ILI9225_DISPLAY_CONTROL_1, 0x0000);
        ili9225_command(dbi, ILI9225_BLANK_PERIOD_CONTROL_1, 0x0808);
        ili9225_command(dbi, ILI9225_FRAME_CYCLE_CONTROL, 0x1100);
        ili9225_command(dbi, ILI9225_INTERFACE_CONTROL, 0x0000);
        ili9225_command(dbi, ILI9225_OSCILLATION_CONTROL, 0x0d01);
        ili9225_command(dbi, ILI9225_VCI_RECYCLING, 0x0020);
        ili9225_command(dbi, ILI9225_RAM_ADDRESS_SET_1, 0x0000);
        ili9225_command(dbi, ILI9225_RAM_ADDRESS_SET_2, 0x0000);

        ili9225_command(dbi, ILI9225_GATE_SCAN_CONTROL, 0x0000);
        ili9225_command(dbi, ILI9225_VERTICAL_SCROLL_1, 0x00db);
        ili9225_command(dbi, ILI9225_VERTICAL_SCROLL_2, 0x0000);
        ili9225_command(dbi, ILI9225_VERTICAL_SCROLL_3, 0x0000);
        ili9225_command(dbi, ILI9225_PARTIAL_DRIVING_POS_1, 0x00db);
        ili9225_command(dbi, ILI9225_PARTIAL_DRIVING_POS_2, 0x0000);

        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_1, 0x0000);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_2, 0x0808);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_3, 0x080a);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_4, 0x000a);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_5, 0x0a08);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_6, 0x0808);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_7, 0x0000);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_8, 0x0a00);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_9, 0x0710);
        ili9225_command(dbi, ILI9225_GAMMA_CONTROL_10, 0x0710);

        ili9225_command(dbi, ILI9225_DISPLAY_CONTROL_1, 0x0012);

        msleep(50);

        ili9225_command(dbi, ILI9225_DISPLAY_CONTROL_1, 0x1017);

        ili9225_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
                         &shadow_plane_state->fmtcnv_state);

out_exit:
        drm_dev_exit(idx);
}

static void ili9225_pipe_disable(struct drm_simple_display_pipe *pipe)
{
        struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
        struct mipi_dbi *dbi = &dbidev->dbi;

        DRM_DEBUG_KMS("\n");

        /*
         * This callback is not protected by drm_dev_enter/exit since we want to
         * turn off the display on regular driver unload. It's highly unlikely
         * that the underlying SPI controller is gone should this be called after
         * unplug.
         */

        ili9225_command(dbi, ILI9225_DISPLAY_CONTROL_1, 0x0000);
        msleep(50);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_2, 0x0007);
        msleep(50);
        ili9225_command(dbi, ILI9225_POWER_CONTROL_1, 0x0a02);
}

static int ili9225_dbi_command(struct mipi_dbi *dbi, u8 *cmd, u8 *par,
                               size_t num)
{
        struct spi_device *spi = dbi->spi;
        unsigned int bpw = 8;
        u32 speed_hz;
        int ret;

        spi_bus_lock(spi->controller);
        gpiod_set_value_cansleep(dbi->dc, 0);
        speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 1);
        ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, cmd, 1);
        spi_bus_unlock(spi->controller);
        if (ret || !num)
                return ret;

        if (*cmd == ILI9225_WRITE_DATA_TO_GRAM && !dbi->swap_bytes)
                bpw = 16;

        spi_bus_lock(spi->controller);
        gpiod_set_value_cansleep(dbi->dc, 1);
        speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
        ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num);
        spi_bus_unlock(spi->controller);

        return ret;
}

static const struct drm_simple_display_pipe_funcs ili9225_pipe_funcs = {
        .mode_valid     = mipi_dbi_pipe_mode_valid,
        .enable         = ili9225_pipe_enable,
        .disable        = ili9225_pipe_disable,
        .update         = ili9225_pipe_update,
        .begin_fb_access = mipi_dbi_pipe_begin_fb_access,
        .end_fb_access  = mipi_dbi_pipe_end_fb_access,
        .reset_plane    = mipi_dbi_pipe_reset_plane,
        .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
        .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
};

static const struct drm_display_mode ili9225_mode = {
        DRM_SIMPLE_MODE(176, 220, 35, 44),
};

DEFINE_DRM_GEM_DMA_FOPS(ili9225_fops);

static const struct drm_driver ili9225_driver = {
        .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
        .fops                   = &ili9225_fops,
        DRM_GEM_DMA_DRIVER_OPS_VMAP,
        DRM_FBDEV_DMA_DRIVER_OPS,
        .name                   = "ili9225",
        .desc                   = "Ilitek ILI9225",
        .major                  = 1,
        .minor                  = 0,
};

static const struct of_device_id ili9225_of_match[] = {
        { .compatible = "vot,v220hf01a-t" },
        {},
};
MODULE_DEVICE_TABLE(of, ili9225_of_match);

static const struct spi_device_id ili9225_id[] = {
        { "v220hf01a-t", 0 },
        { },
};
MODULE_DEVICE_TABLE(spi, ili9225_id);

static int ili9225_probe(struct spi_device *spi)
{
        struct device *dev = &spi->dev;
        struct mipi_dbi_dev *dbidev;
        struct drm_device *drm;
        struct mipi_dbi *dbi;
        struct gpio_desc *rs;
        u32 rotation = 0;
        int ret;

        dbidev = devm_drm_dev_alloc(dev, &ili9225_driver,
                                    struct mipi_dbi_dev, drm);
        if (IS_ERR(dbidev))
                return PTR_ERR(dbidev);

        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");

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

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

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

        /* override the command function set in  mipi_dbi_spi_init() */
        dbi->command = ili9225_dbi_command;

        ret = mipi_dbi_dev_init(dbidev, &ili9225_pipe_funcs, &ili9225_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 ili9225_remove(struct spi_device *spi)
{
        struct drm_device *drm = spi_get_drvdata(spi);

        drm_dev_unplug(drm);
        drm_atomic_helper_shutdown(drm);
}

static void ili9225_shutdown(struct spi_device *spi)
{
        drm_atomic_helper_shutdown(spi_get_drvdata(spi));
}

static struct spi_driver ili9225_spi_driver = {
        .driver = {
                .name = "ili9225",
                .of_match_table = ili9225_of_match,
        },
        .id_table = ili9225_id,
        .probe = ili9225_probe,
        .remove = ili9225_remove,
        .shutdown = ili9225_shutdown,
};
module_spi_driver(ili9225_spi_driver);

MODULE_DESCRIPTION("Ilitek ILI9225 DRM driver");
MODULE_AUTHOR("David Lechner <david@lechnology.com>");
MODULE_LICENSE("GPL");