// SPDX-License-Identifier: GPL-2.0-or-later
/* exynos_drm_vidi.c
 *
 * Copyright (C) 2012 Samsung Electronics Co.Ltd
 * Authors:
 *      Inki Dae <inki.dae@samsung.com>
 */

#include <linux/component.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/timer.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_vblank.h>
#include <drm/exynos_drm.h>

#include "exynos_drm_crtc.h"
#include "exynos_drm_drv.h"
#include "exynos_drm_fb.h"
#include "exynos_drm_plane.h"
#include "exynos_drm_vidi.h"

/* VIDI uses fixed refresh rate of 50Hz */
#define VIDI_REFRESH_TIME (1000 / 50)

/* vidi has totally three virtual windows. */
#define WINDOWS_NR              3

#define ctx_from_connector(c)   container_of(c, struct vidi_context, \
                                        connector)

struct vidi_context {
        struct drm_encoder              encoder;
        struct drm_device               *drm_dev;
        struct device                   *dev;
        struct exynos_drm_crtc          *crtc;
        struct drm_connector            connector;
        struct exynos_drm_plane         planes[WINDOWS_NR];
        const struct drm_edid           *raw_edid;
        unsigned int                    clkdiv;
        unsigned int                    connected;
        bool                            suspended;
        struct timer_list               timer;
        struct mutex                    lock;
};

static inline struct vidi_context *encoder_to_vidi(struct drm_encoder *e)
{
        return container_of(e, struct vidi_context, encoder);
}

static const char fake_edid_info[] = {
        0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x4c, 0x2d, 0x05, 0x05,
        0x00, 0x00, 0x00, 0x00, 0x30, 0x12, 0x01, 0x03, 0x80, 0x10, 0x09, 0x78,
        0x0a, 0xee, 0x91, 0xa3, 0x54, 0x4c, 0x99, 0x26, 0x0f, 0x50, 0x54, 0xbd,
        0xee, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
        0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x66, 0x21, 0x50, 0xb0, 0x51, 0x00,
        0x1b, 0x30, 0x40, 0x70, 0x36, 0x00, 0xa0, 0x5a, 0x00, 0x00, 0x00, 0x1e,
        0x01, 0x1d, 0x00, 0x72, 0x51, 0xd0, 0x1e, 0x20, 0x6e, 0x28, 0x55, 0x00,
        0xa0, 0x5a, 0x00, 0x00, 0x00, 0x1e, 0x00, 0x00, 0x00, 0xfd, 0x00, 0x18,
        0x4b, 0x1a, 0x44, 0x17, 0x00, 0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
        0x00, 0x00, 0x00, 0xfc, 0x00, 0x53, 0x41, 0x4d, 0x53, 0x55, 0x4e, 0x47,
        0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x01, 0xbc, 0x02, 0x03, 0x1e, 0xf1,
        0x46, 0x84, 0x05, 0x03, 0x10, 0x20, 0x22, 0x23, 0x09, 0x07, 0x07, 0x83,
        0x01, 0x00, 0x00, 0xe2, 0x00, 0x0f, 0x67, 0x03, 0x0c, 0x00, 0x10, 0x00,
        0xb8, 0x2d, 0x01, 0x1d, 0x80, 0x18, 0x71, 0x1c, 0x16, 0x20, 0x58, 0x2c,
        0x25, 0x00, 0xa0, 0x5a, 0x00, 0x00, 0x00, 0x9e, 0x8c, 0x0a, 0xd0, 0x8a,
        0x20, 0xe0, 0x2d, 0x10, 0x10, 0x3e, 0x96, 0x00, 0xa0, 0x5a, 0x00, 0x00,
        0x00, 0x18, 0x02, 0x3a, 0x80, 0x18, 0x71, 0x38, 0x2d, 0x40, 0x58, 0x2c,
        0x45, 0x00, 0xa0, 0x5a, 0x00, 0x00, 0x00, 0x1e, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x06
};

static const uint32_t formats[] = {
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_ARGB8888,
        DRM_FORMAT_NV12,
};

static const enum drm_plane_type vidi_win_types[WINDOWS_NR] = {
        DRM_PLANE_TYPE_PRIMARY,
        DRM_PLANE_TYPE_OVERLAY,
        DRM_PLANE_TYPE_CURSOR,
};

static int vidi_enable_vblank(struct exynos_drm_crtc *crtc)
{
        struct vidi_context *ctx = crtc->ctx;

        if (ctx->suspended)
                return -EPERM;

        mod_timer(&ctx->timer,
                jiffies + msecs_to_jiffies(VIDI_REFRESH_TIME) - 1);

        return 0;
}

static void vidi_disable_vblank(struct exynos_drm_crtc *crtc)
{
}

static void vidi_update_plane(struct exynos_drm_crtc *crtc,
                              struct exynos_drm_plane *plane)
{
        struct drm_plane_state *state = plane->base.state;
        struct vidi_context *ctx = crtc->ctx;
        dma_addr_t addr;

        if (ctx->suspended)
                return;

        addr = exynos_drm_fb_dma_addr(state->fb, 0);
        DRM_DEV_DEBUG_KMS(ctx->dev, "dma_addr = %pad\n", &addr);
}

static void vidi_atomic_enable(struct exynos_drm_crtc *crtc)
{
        struct vidi_context *ctx = crtc->ctx;

        mutex_lock(&ctx->lock);

        ctx->suspended = false;

        mutex_unlock(&ctx->lock);

        drm_crtc_vblank_on(&crtc->base);
}

static void vidi_atomic_disable(struct exynos_drm_crtc *crtc)
{
        struct vidi_context *ctx = crtc->ctx;

        drm_crtc_vblank_off(&crtc->base);

        mutex_lock(&ctx->lock);

        ctx->suspended = true;

        mutex_unlock(&ctx->lock);
}

static const struct exynos_drm_crtc_ops vidi_crtc_ops = {
        .atomic_enable = vidi_atomic_enable,
        .atomic_disable = vidi_atomic_disable,
        .enable_vblank = vidi_enable_vblank,
        .disable_vblank = vidi_disable_vblank,
        .update_plane = vidi_update_plane,
        .atomic_flush = exynos_crtc_handle_event,
};

static void vidi_fake_vblank_timer(struct timer_list *t)
{
        struct vidi_context *ctx = timer_container_of(ctx, t, timer);

        if (drm_crtc_handle_vblank(&ctx->crtc->base))
                mod_timer(&ctx->timer,
                        jiffies + msecs_to_jiffies(VIDI_REFRESH_TIME) - 1);
}

static ssize_t vidi_show_connection(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct vidi_context *ctx = dev_get_drvdata(dev);
        int rc;

        mutex_lock(&ctx->lock);

        rc = sprintf(buf, "%d\n", ctx->connected);

        mutex_unlock(&ctx->lock);

        return rc;
}

static ssize_t vidi_store_connection(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t len)
{
        struct vidi_context *ctx = dev_get_drvdata(dev);
        int ret, new_connected;

        ret = kstrtoint(buf, 0, &new_connected);
        if (ret)
                return ret;
        if (new_connected > 1)
                return -EINVAL;

        mutex_lock(&ctx->lock);

        /*
         * Use fake edid data for test. If raw_edid is set then it can't be
         * tested.
         */
        if (ctx->raw_edid) {
                DRM_DEV_DEBUG_KMS(dev, "edid data is not fake data.\n");
                ret = -EINVAL;
                goto fail;
        }

        ctx->connected = new_connected;
        mutex_unlock(&ctx->lock);

        DRM_DEV_DEBUG_KMS(dev, "requested connection.\n");

        drm_helper_hpd_irq_event(ctx->drm_dev);

        return len;
fail:
        mutex_unlock(&ctx->lock);
        return ret;
}

static DEVICE_ATTR(connection, 0644, vidi_show_connection,
                        vidi_store_connection);

static struct attribute *vidi_attrs[] = {
        &dev_attr_connection.attr,
        NULL,
};
ATTRIBUTE_GROUPS(vidi);

int vidi_connection_ioctl(struct drm_device *drm_dev, void *data,
                                struct drm_file *file_priv)
{
        struct exynos_drm_private *priv = drm_dev->dev_private;
        struct device *dev = priv ? priv->vidi_dev : NULL;
        struct vidi_context *ctx = dev ? dev_get_drvdata(dev) : NULL;
        struct drm_exynos_vidi_connection *vidi = data;

        if (!ctx)
                return -ENODEV;

        if (!vidi) {
                DRM_DEV_DEBUG_KMS(ctx->dev,
                                  "user data for vidi is null.\n");
                return -EINVAL;
        }

        if (vidi->connection > 1) {
                DRM_DEV_DEBUG_KMS(ctx->dev,
                                  "connection should be 0 or 1.\n");
                return -EINVAL;
        }

        mutex_lock(&ctx->lock);
        if (ctx->connected == vidi->connection) {
                mutex_unlock(&ctx->lock);
                DRM_DEV_DEBUG_KMS(ctx->dev,
                                  "same connection request.\n");
                return -EINVAL;
        }
        mutex_unlock(&ctx->lock);

        if (vidi->connection) {
                const struct drm_edid *drm_edid;
                const void __user *edid_userptr = u64_to_user_ptr(vidi->edid);
                void *edid_buf;
                struct edid hdr;
                size_t size;

                if (copy_from_user(&hdr, edid_userptr, sizeof(hdr)))
                        return -EFAULT;

                size = (hdr.extensions + 1) * EDID_LENGTH;

                edid_buf = kmalloc(size, GFP_KERNEL);
                if (!edid_buf)
                        return -ENOMEM;

                if (copy_from_user(edid_buf, edid_userptr, size)) {
                        kfree(edid_buf);
                        return -EFAULT;
                }

                drm_edid = drm_edid_alloc(edid_buf, size);
                kfree(edid_buf);
                if (!drm_edid)
                        return -ENOMEM;

                if (!drm_edid_valid(drm_edid)) {
                        drm_edid_free(drm_edid);
                        DRM_DEV_DEBUG_KMS(ctx->dev,
                                          "edid data is invalid.\n");
                        return -EINVAL;
                }
                mutex_lock(&ctx->lock);
                ctx->raw_edid = drm_edid;
                mutex_unlock(&ctx->lock);
        } else {
                /* with connection = 0, free raw_edid */
                mutex_lock(&ctx->lock);
                drm_edid_free(ctx->raw_edid);
                ctx->raw_edid = NULL;
                mutex_unlock(&ctx->lock);
        }

        mutex_lock(&ctx->lock);
        ctx->connected = vidi->connection;
        mutex_unlock(&ctx->lock);

        drm_helper_hpd_irq_event(ctx->drm_dev);

        return 0;
}

static enum drm_connector_status vidi_detect(struct drm_connector *connector,
                        bool force)
{
        struct vidi_context *ctx = ctx_from_connector(connector);

        /*
         * connection request would come from user side
         * to do hotplug through specific ioctl.
         */
        return READ_ONCE(ctx->connected) ? connector_status_connected :
                        connector_status_disconnected;
}

static void vidi_connector_destroy(struct drm_connector *connector)
{
}

static const struct drm_connector_funcs vidi_connector_funcs = {
        .fill_modes = drm_helper_probe_single_connector_modes,
        .detect = vidi_detect,
        .destroy = vidi_connector_destroy,
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int vidi_get_modes(struct drm_connector *connector)
{
        struct vidi_context *ctx = ctx_from_connector(connector);
        const struct drm_edid *drm_edid;
        int count;

        mutex_lock(&ctx->lock);

        if (ctx->raw_edid)
                drm_edid = drm_edid_dup(ctx->raw_edid);
        else
                drm_edid = drm_edid_alloc(fake_edid_info, sizeof(fake_edid_info));

        mutex_unlock(&ctx->lock);

        drm_edid_connector_update(connector, drm_edid);

        count = drm_edid_connector_add_modes(connector);

        drm_edid_free(drm_edid);

        return count;
}

static const struct drm_connector_helper_funcs vidi_connector_helper_funcs = {
        .get_modes = vidi_get_modes,
};

static int vidi_create_connector(struct drm_encoder *encoder)
{
        struct vidi_context *ctx = encoder_to_vidi(encoder);
        struct drm_connector *connector = &ctx->connector;
        int ret;

        connector->polled = DRM_CONNECTOR_POLL_HPD;

        ret = drm_connector_init(ctx->drm_dev, connector,
                        &vidi_connector_funcs, DRM_MODE_CONNECTOR_VIRTUAL);
        if (ret) {
                DRM_DEV_ERROR(ctx->dev,
                              "Failed to initialize connector with drm\n");
                return ret;
        }

        drm_connector_helper_add(connector, &vidi_connector_helper_funcs);
        drm_connector_attach_encoder(connector, encoder);

        return 0;
}

static void exynos_vidi_mode_set(struct drm_encoder *encoder,
                               struct drm_display_mode *mode,
                               struct drm_display_mode *adjusted_mode)
{
}

static void exynos_vidi_enable(struct drm_encoder *encoder)
{
}

static void exynos_vidi_disable(struct drm_encoder *encoder)
{
}

static const struct drm_encoder_helper_funcs exynos_vidi_encoder_helper_funcs = {
        .mode_set = exynos_vidi_mode_set,
        .enable = exynos_vidi_enable,
        .disable = exynos_vidi_disable,
};

static int vidi_bind(struct device *dev, struct device *master, void *data)
{
        struct vidi_context *ctx = dev_get_drvdata(dev);
        struct drm_device *drm_dev = data;
        struct exynos_drm_private *priv = drm_dev->dev_private;
        struct drm_encoder *encoder = &ctx->encoder;
        struct exynos_drm_plane *exynos_plane;
        struct exynos_drm_plane_config plane_config = { 0 };
        unsigned int i;
        int ret;

        ctx->drm_dev = drm_dev;
        if (priv)
                priv->vidi_dev = dev;

        plane_config.pixel_formats = formats;
        plane_config.num_pixel_formats = ARRAY_SIZE(formats);

        for (i = 0; i < WINDOWS_NR; i++) {
                plane_config.zpos = i;
                plane_config.type = vidi_win_types[i];

                ret = exynos_plane_init(drm_dev, &ctx->planes[i], i,
                                        &plane_config);
                if (ret)
                        return ret;
        }

        exynos_plane = &ctx->planes[DEFAULT_WIN];
        ctx->crtc = exynos_drm_crtc_create(drm_dev, &exynos_plane->base,
                        EXYNOS_DISPLAY_TYPE_VIDI, &vidi_crtc_ops, ctx);
        if (IS_ERR(ctx->crtc)) {
                DRM_DEV_ERROR(dev, "failed to create crtc.\n");
                return PTR_ERR(ctx->crtc);
        }

        drm_simple_encoder_init(drm_dev, encoder, DRM_MODE_ENCODER_TMDS);

        drm_encoder_helper_add(encoder, &exynos_vidi_encoder_helper_funcs);

        ret = exynos_drm_set_possible_crtcs(encoder, EXYNOS_DISPLAY_TYPE_VIDI);
        if (ret < 0)
                return ret;

        ret = vidi_create_connector(encoder);
        if (ret) {
                DRM_DEV_ERROR(dev, "failed to create connector ret = %d\n",
                              ret);
                drm_encoder_cleanup(encoder);
                return ret;
        }

        return 0;
}


static void vidi_unbind(struct device *dev, struct device *master, void *data)
{
        struct vidi_context *ctx = dev_get_drvdata(dev);
        struct drm_device *drm_dev = data;
        struct exynos_drm_private *priv = drm_dev->dev_private;

        timer_delete_sync(&ctx->timer);
        if (priv)
                priv->vidi_dev = NULL;
}

static const struct component_ops vidi_component_ops = {
        .bind   = vidi_bind,
        .unbind = vidi_unbind,
};

static int vidi_probe(struct platform_device *pdev)
{
        struct vidi_context *ctx;
        struct device *dev = &pdev->dev;

        ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
        if (!ctx)
                return -ENOMEM;

        ctx->dev = dev;

        timer_setup(&ctx->timer, vidi_fake_vblank_timer, 0);

        mutex_init(&ctx->lock);

        platform_set_drvdata(pdev, ctx);

        return component_add(dev, &vidi_component_ops);
}

static void vidi_remove(struct platform_device *pdev)
{
        struct vidi_context *ctx = platform_get_drvdata(pdev);

        mutex_lock(&ctx->lock);

        drm_edid_free(ctx->raw_edid);
        ctx->raw_edid = NULL;

        mutex_unlock(&ctx->lock);

        component_del(&pdev->dev, &vidi_component_ops);
}

struct platform_driver vidi_driver = {
        .probe          = vidi_probe,
        .remove         = vidi_remove,
        .driver         = {
                .name   = "exynos-drm-vidi",
                .dev_groups = vidi_groups,
        },
};