// SPDX-License-Identifier: GPL-2.0-only

#include <linux/component.h>
#include <linux/iopoll.h>
#include <linux/of.h>
#include <linux/platform_device.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_bridge_connector.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_dma_helper.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_of.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_vblank.h>

#define ADP_INT_STATUS 0x34
#define ADP_INT_STATUS_INT_MASK 0x7
#define ADP_INT_STATUS_VBLANK 0x1
#define ADP_CTRL 0x100
#define ADP_CTRL_VBLANK_ON 0x12
#define ADP_CTRL_FIFO_ON 0x601
#define ADP_SCREEN_SIZE 0x0c
#define ADP_SCREEN_HSIZE GENMASK(15, 0)
#define ADP_SCREEN_VSIZE GENMASK(31, 16)

#define ADBE_FIFO 0x10c0
#define ADBE_FIFO_SYNC 0xc0000000

#define ADBE_BLEND_BYPASS 0x2020
#define ADBE_BLEND_EN1 0x2028
#define ADBE_BLEND_EN2 0x2074
#define ADBE_BLEND_EN3 0x202c
#define ADBE_BLEND_EN4 0x2034
#define ADBE_MASK_BUF 0x2200

#define ADBE_SRC_START 0x4040
#define ADBE_SRC_SIZE 0x4048
#define ADBE_DST_START 0x4050
#define ADBE_DST_SIZE 0x4054
#define ADBE_STRIDE 0x4038
#define ADBE_FB_BASE 0x4030

#define ADBE_LAYER_EN1 0x4020
#define ADBE_LAYER_EN2 0x4068
#define ADBE_LAYER_EN3 0x40b4
#define ADBE_LAYER_EN4 0x40f4
#define ADBE_SCALE_CTL 0x40ac
#define ADBE_SCALE_CTL_BYPASS 0x100000

#define ADBE_LAYER_CTL 0x1038
#define ADBE_LAYER_CTL_ENABLE 0x10000

#define ADBE_PIX_FMT 0x402c
#define ADBE_PIX_FMT_XRGB32 0x53e4001

static int adp_open(struct inode *inode, struct file *filp)
{
	/*
	 * The modesetting driver does not check the non-desktop connector
	 * property and keeps the device open and locked. If the touchbar daemon
	 * opens the device first, modesetting breaks the whole X session.
	 * Simply refuse to open the device for X11 server processes as
	 * workaround.
	 */
	if (current->comm[0] == 'X')
		return -EBUSY;

	return drm_open(inode, filp);
}

static const struct file_operations adp_fops = {
	.owner          = THIS_MODULE,
	.open           = adp_open,
	.release        = drm_release,
	.unlocked_ioctl = drm_ioctl,
	.compat_ioctl   = drm_compat_ioctl,
	.poll           = drm_poll,
	.read           = drm_read,
	.llseek         = noop_llseek,
	.mmap           = drm_gem_mmap,
	.fop_flags      = FOP_UNSIGNED_OFFSET,
	DRM_GEM_DMA_UNMAPPED_AREA_FOPS
};

static int adp_drm_gem_dumb_create(struct drm_file *file_priv,
					struct drm_device *drm,
					struct drm_mode_create_dumb *args)
{
	args->height = ALIGN(args->height, 64);
	args->size = args->pitch * args->height;

	return drm_gem_dma_dumb_create_internal(file_priv, drm, args);
}

static const struct drm_driver adp_driver = {
	.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
	.fops = &adp_fops,
	DRM_GEM_DMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE(adp_drm_gem_dumb_create),
	.name = "adp",
	.desc = "Apple Display Pipe DRM Driver",
	.major = 0,
	.minor = 1,
};

struct adp_drv_private {
	struct drm_device drm;
	struct drm_crtc crtc;
	struct drm_encoder *encoder;
	struct drm_connector *connector;
	struct drm_bridge *next_bridge;
	void __iomem *be;
	void __iomem *fe;
	u32 *mask_buf;
	u64 mask_buf_size;
	dma_addr_t mask_iova;
	int be_irq;
	int fe_irq;
	spinlock_t irq_lock;
	struct drm_pending_vblank_event *event;
};

#define to_adp(x) container_of(x, struct adp_drv_private, drm)
#define crtc_to_adp(x) container_of(x, struct adp_drv_private, crtc)

static int adp_plane_atomic_check(struct drm_plane *plane,
				    struct drm_atomic_state *state)
{
	struct drm_plane_state *new_plane_state;
	struct drm_crtc_state *crtc_state;

	new_plane_state = drm_atomic_get_new_plane_state(state, plane);

	if (!new_plane_state->crtc)
		return 0;

	crtc_state = drm_atomic_get_crtc_state(state, new_plane_state->crtc);
	if (IS_ERR(crtc_state))
		return PTR_ERR(crtc_state);

	return drm_atomic_helper_check_plane_state(new_plane_state,
						   crtc_state,
						   DRM_PLANE_NO_SCALING,
						   DRM_PLANE_NO_SCALING,
						   true, true);
}

static void adp_plane_atomic_update(struct drm_plane *plane,
				    struct drm_atomic_state *state)
{
	struct adp_drv_private *adp;
	struct drm_rect src_rect;
	struct drm_gem_dma_object *obj;
	struct drm_framebuffer *fb;
	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state, plane);
	u32 src_pos, src_size, dst_pos, dst_size;

	if (!plane || !new_state)
		return;

	fb = new_state->fb;
	if (!fb)
		return;
	adp = to_adp(plane->dev);

	drm_rect_fp_to_int(&src_rect, &new_state->src);
	src_pos = src_rect.x1 << 16 | src_rect.y1;
	dst_pos = new_state->dst.x1 << 16 | new_state->dst.y1;
	src_size = drm_rect_width(&src_rect) << 16 | drm_rect_height(&src_rect);
	dst_size = drm_rect_width(&new_state->dst) << 16 |
		drm_rect_height(&new_state->dst);
	writel(src_pos, adp->be + ADBE_SRC_START);
	writel(src_size, adp->be + ADBE_SRC_SIZE);
	writel(dst_pos, adp->be + ADBE_DST_START);
	writel(dst_size, adp->be + ADBE_DST_SIZE);
	writel(fb->pitches[0], adp->be + ADBE_STRIDE);
	obj = drm_fb_dma_get_gem_obj(fb, 0);
	if (obj)
		writel(obj->dma_addr + fb->offsets[0], adp->be + ADBE_FB_BASE);

	writel(BIT(0), adp->be + ADBE_LAYER_EN1);
	writel(BIT(0), adp->be + ADBE_LAYER_EN2);
	writel(BIT(0), adp->be + ADBE_LAYER_EN3);
	writel(BIT(0), adp->be + ADBE_LAYER_EN4);
	writel(ADBE_SCALE_CTL_BYPASS, adp->be + ADBE_SCALE_CTL);
	writel(ADBE_LAYER_CTL_ENABLE | BIT(0), adp->be + ADBE_LAYER_CTL);
	writel(ADBE_PIX_FMT_XRGB32, adp->be + ADBE_PIX_FMT);
}

static void adp_plane_atomic_disable(struct drm_plane *plane,
				     struct drm_atomic_state *state)
{
	struct adp_drv_private *adp = to_adp(plane->dev);

	writel(0x0, adp->be + ADBE_LAYER_EN1);
	writel(0x0, adp->be + ADBE_LAYER_EN2);
	writel(0x0, adp->be + ADBE_LAYER_EN3);
	writel(0x0, adp->be + ADBE_LAYER_EN4);
	writel(ADBE_LAYER_CTL_ENABLE, adp->be + ADBE_LAYER_CTL);
}

static const struct drm_plane_helper_funcs adp_plane_helper_funcs = {
	.atomic_check = adp_plane_atomic_check,
	.atomic_update = adp_plane_atomic_update,
	.atomic_disable = adp_plane_atomic_disable,
	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS
};

static const struct drm_plane_funcs adp_plane_funcs = {
	.update_plane = drm_atomic_helper_update_plane,
	.disable_plane = drm_atomic_helper_disable_plane,
	DRM_GEM_SHADOW_PLANE_FUNCS
};

static const u32 plane_formats[] = {
	DRM_FORMAT_XRGB8888,
};

#define ALL_CRTCS 1

static struct drm_plane *adp_plane_new(struct adp_drv_private *adp)
{
	struct drm_device *drm = &adp->drm;
	struct drm_plane *plane;

	plane = __drmm_universal_plane_alloc(drm, sizeof(struct drm_plane), 0,
					     ALL_CRTCS, &adp_plane_funcs,
					     plane_formats, ARRAY_SIZE(plane_formats),
					     NULL, DRM_PLANE_TYPE_PRIMARY, "plane");
	if (IS_ERR(plane)) {
		drm_err(drm, "failed to allocate plane");
		return plane;
	}

	drm_plane_helper_add(plane, &adp_plane_helper_funcs);
	return plane;
}

static void adp_enable_vblank(struct adp_drv_private *adp)
{
	u32 cur_ctrl;

	writel(ADP_INT_STATUS_INT_MASK, adp->fe + ADP_INT_STATUS);

	cur_ctrl = readl(adp->fe + ADP_CTRL);
	writel(cur_ctrl | ADP_CTRL_VBLANK_ON, adp->fe + ADP_CTRL);
}

static int adp_crtc_enable_vblank(struct drm_crtc *crtc)
{
	struct drm_device *dev = crtc->dev;
	struct adp_drv_private *adp = to_adp(dev);

	adp_enable_vblank(adp);

	return 0;
}

static void adp_disable_vblank(struct adp_drv_private *adp)
{
	u32 cur_ctrl;

	cur_ctrl = readl(adp->fe + ADP_CTRL);
	writel(cur_ctrl & ~ADP_CTRL_VBLANK_ON, adp->fe + ADP_CTRL);
	writel(ADP_INT_STATUS_INT_MASK, adp->fe + ADP_INT_STATUS);
}

static void adp_crtc_disable_vblank(struct drm_crtc *crtc)
{
	struct drm_device *dev = crtc->dev;
	struct adp_drv_private *adp = to_adp(dev);

	adp_disable_vblank(adp);
}

static void adp_crtc_atomic_enable(struct drm_crtc *crtc,
				   struct drm_atomic_state *state)
{
	struct adp_drv_private *adp = crtc_to_adp(crtc);

	writel(BIT(0), adp->be + ADBE_BLEND_EN2);
	writel(BIT(4), adp->be + ADBE_BLEND_EN1);
	writel(BIT(0), adp->be + ADBE_BLEND_EN3);
	writel(BIT(0), adp->be + ADBE_BLEND_BYPASS);
	writel(BIT(0), adp->be + ADBE_BLEND_EN4);
}

static void adp_crtc_atomic_disable(struct drm_crtc *crtc,
				    struct drm_atomic_state *state)
{
	struct adp_drv_private *adp = crtc_to_adp(crtc);
	struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state, crtc);

	drm_atomic_helper_disable_planes_on_crtc(old_state, false);

	writel(0x0, adp->be + ADBE_BLEND_EN2);
	writel(0x0, adp->be + ADBE_BLEND_EN1);
	writel(0x0, adp->be + ADBE_BLEND_EN3);
	writel(0x0, adp->be + ADBE_BLEND_BYPASS);
	writel(0x0, adp->be + ADBE_BLEND_EN4);
	drm_crtc_vblank_off(crtc);
}

static void adp_crtc_atomic_flush(struct drm_crtc *crtc,
				  struct drm_atomic_state *state)
{
	u32 frame_num = 1;
	struct adp_drv_private *adp = crtc_to_adp(crtc);
	struct drm_crtc_state *new_state = drm_atomic_get_new_crtc_state(state, crtc);
	u64 new_size = ALIGN(new_state->mode.hdisplay *
			     new_state->mode.vdisplay * 4, PAGE_SIZE);

	if (new_size != adp->mask_buf_size) {
		if (adp->mask_buf)
			dma_free_coherent(crtc->dev->dev, adp->mask_buf_size,
					  adp->mask_buf, adp->mask_iova);
		adp->mask_buf = NULL;
		if (new_size != 0) {
			adp->mask_buf = dma_alloc_coherent(crtc->dev->dev, new_size,
							   &adp->mask_iova, GFP_KERNEL);
			memset(adp->mask_buf, 0xFF, new_size);
			writel(adp->mask_iova, adp->be + ADBE_MASK_BUF);
		}
		adp->mask_buf_size = new_size;
	}
	writel(ADBE_FIFO_SYNC | frame_num, adp->be + ADBE_FIFO);
	//FIXME: use adbe flush interrupt
	spin_lock_irq(&crtc->dev->event_lock);
	if (crtc->state->event) {
		drm_crtc_vblank_get(crtc);
		adp->event = crtc->state->event;
	}
	crtc->state->event = NULL;
	spin_unlock_irq(&crtc->dev->event_lock);
}

static const struct drm_crtc_funcs adp_crtc_funcs = {
	.destroy = drm_crtc_cleanup,
	.set_config = drm_atomic_helper_set_config,
	.page_flip = drm_atomic_helper_page_flip,
	.reset = drm_atomic_helper_crtc_reset,
	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
	.enable_vblank = adp_crtc_enable_vblank,
	.disable_vblank = adp_crtc_disable_vblank,
};


static const struct drm_crtc_helper_funcs adp_crtc_helper_funcs = {
	.atomic_enable = adp_crtc_atomic_enable,
	.atomic_disable = adp_crtc_atomic_disable,
	.atomic_flush = adp_crtc_atomic_flush,
};

static int adp_setup_crtc(struct adp_drv_private *adp)
{
	struct drm_device *drm = &adp->drm;
	struct drm_plane *primary;
	int ret;

	primary = adp_plane_new(adp);
	if (IS_ERR(primary))
		return PTR_ERR(primary);

	ret = drm_crtc_init_with_planes(drm, &adp->crtc, primary,
					NULL, &adp_crtc_funcs, NULL);
	if (ret)
		return ret;

	drm_crtc_helper_add(&adp->crtc, &adp_crtc_helper_funcs);
	return 0;
}

static const struct drm_mode_config_funcs adp_mode_config_funcs = {
	.fb_create = drm_gem_fb_create_with_dirty,
	.atomic_check = drm_atomic_helper_check,
	.atomic_commit = drm_atomic_helper_commit,
};

static int adp_setup_mode_config(struct adp_drv_private *adp)
{
	struct drm_device *drm = &adp->drm;
	int ret;
	u32 size;

	ret = drmm_mode_config_init(drm);
	if (ret)
		return ret;

	/*
	 * Query screen size restrict the frame buffer size to the screen size
	 * aligned to the next multiple of 64. This is not necessary but can be
	 * used as simple check for non-desktop devices.
	 * Xorg's modesetting driver does not care about the connector
	 * "non-desktop" property. The max frame buffer width or height can be
	 * easily checked and a device can be reject if the max width/height is
	 * smaller than 120 for example.
	 * Any touchbar daemon is not limited by this small framebuffer size.
	 */
	size = readl(adp->fe + ADP_SCREEN_SIZE);

	drm->mode_config.min_width = 32;
	drm->mode_config.min_height = 32;
	drm->mode_config.max_width = ALIGN(FIELD_GET(ADP_SCREEN_HSIZE, size), 64);
	drm->mode_config.max_height = ALIGN(FIELD_GET(ADP_SCREEN_VSIZE, size), 64);
	drm->mode_config.preferred_depth = 24;
	drm->mode_config.prefer_shadow = 0;
	drm->mode_config.funcs = &adp_mode_config_funcs;

	ret = adp_setup_crtc(adp);
	if (ret) {
		drm_err(drm, "failed to create crtc");
		return ret;
	}

	adp->encoder = drmm_plain_encoder_alloc(drm, NULL, DRM_MODE_ENCODER_DSI, NULL);
	if (IS_ERR(adp->encoder)) {
		drm_err(drm, "failed to init encoder");
		return PTR_ERR(adp->encoder);
	}
	adp->encoder->possible_crtcs = ALL_CRTCS;

	ret = drm_bridge_attach(adp->encoder, adp->next_bridge, NULL,
				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
	if (ret) {
		drm_err(drm, "failed to init bridge chain");
		return ret;
	}

	adp->connector = drm_bridge_connector_init(drm, adp->encoder);
	if (IS_ERR(adp->connector))
		return PTR_ERR(adp->connector);

	drm_connector_attach_encoder(adp->connector, adp->encoder);

	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
	if (ret < 0) {
		drm_err(drm, "failed to initialize vblank");
		return ret;
	}

	drm_mode_config_reset(drm);

	return 0;
}

static int adp_parse_of(struct platform_device *pdev, struct adp_drv_private *adp)
{
	struct device *dev = &pdev->dev;

	adp->be = devm_platform_ioremap_resource_byname(pdev, "be");
	if (IS_ERR(adp->be)) {
		dev_err(dev, "failed to map display backend mmio");
		return PTR_ERR(adp->be);
	}

	adp->fe = devm_platform_ioremap_resource_byname(pdev, "fe");
	if (IS_ERR(adp->fe)) {
		dev_err(dev, "failed to map display pipe mmio");
		return PTR_ERR(adp->fe);
	}

	adp->be_irq = platform_get_irq_byname(pdev, "be");
	if (adp->be_irq < 0)
		return adp->be_irq;

	adp->fe_irq = platform_get_irq_byname(pdev, "fe");
	if (adp->fe_irq < 0)
		return adp->fe_irq;

	return 0;
}

static irqreturn_t adp_fe_irq(int irq, void *arg)
{
	struct adp_drv_private *adp = (struct adp_drv_private *)arg;
	u32 int_status;
	u32 int_ctl;

	spin_lock(&adp->irq_lock);

	int_status = readl(adp->fe + ADP_INT_STATUS);
	if (int_status & ADP_INT_STATUS_VBLANK) {
		drm_crtc_handle_vblank(&adp->crtc);
		spin_lock(&adp->crtc.dev->event_lock);
		if (adp->event) {
			int_ctl = readl(adp->fe + ADP_CTRL);
			if ((int_ctl & 0xF00) == 0x600) {
				drm_crtc_send_vblank_event(&adp->crtc, adp->event);
				adp->event = NULL;
				drm_crtc_vblank_put(&adp->crtc);
			}
		}
		spin_unlock(&adp->crtc.dev->event_lock);
	}

	writel(int_status, adp->fe + ADP_INT_STATUS);

	spin_unlock(&adp->irq_lock);

	return IRQ_HANDLED;
}

static int adp_drm_bind(struct device *dev)
{
	struct drm_device *drm = dev_get_drvdata(dev);
	struct adp_drv_private *adp = to_adp(drm);
	int err;

	adp_disable_vblank(adp);
	writel(ADP_CTRL_FIFO_ON | ADP_CTRL_VBLANK_ON, adp->fe + ADP_CTRL);

	adp->next_bridge = drmm_of_get_bridge(&adp->drm, dev->of_node, 0, 0);
	if (IS_ERR(adp->next_bridge)) {
		dev_err(dev, "failed to find next bridge");
		return PTR_ERR(adp->next_bridge);
	}

	err = adp_setup_mode_config(adp);
	if (err < 0)
		return err;

	err = request_irq(adp->fe_irq, adp_fe_irq, 0, "adp-fe", adp);
	if (err)
		return err;

	err = drm_dev_register(&adp->drm, 0);
	if (err)
		return err;

	return 0;
}

static void adp_drm_unbind(struct device *dev)
{
	struct drm_device *drm = dev_get_drvdata(dev);
	struct adp_drv_private *adp = to_adp(drm);

	drm_dev_unregister(drm);
	drm_atomic_helper_shutdown(drm);
	free_irq(adp->fe_irq, adp);
}

static const struct component_master_ops adp_master_ops = {
	.bind	= adp_drm_bind,
	.unbind = adp_drm_unbind,
};

static int compare_dev(struct device *dev, void *data)
{
	return dev->of_node == data;
}

static int adp_probe(struct platform_device *pdev)
{
	struct device_node *port;
	struct component_match *match = NULL;
	struct adp_drv_private *adp;
	int err;

	adp = devm_drm_dev_alloc(&pdev->dev, &adp_driver, struct adp_drv_private, drm);
	if (IS_ERR(adp))
		return PTR_ERR(adp);

	spin_lock_init(&adp->irq_lock);

	dev_set_drvdata(&pdev->dev, &adp->drm);

	err = adp_parse_of(pdev, adp);
	if (err < 0)
		return err;

	port = of_graph_get_remote_node(pdev->dev.of_node, 0, 0);
	if (!port)
		return -ENODEV;

	drm_of_component_match_add(&pdev->dev, &match, compare_dev, port);
	of_node_put(port);

	return component_master_add_with_match(&pdev->dev, &adp_master_ops, match);
}

static void adp_remove(struct platform_device *pdev)
{
	component_master_del(&pdev->dev, &adp_master_ops);
	dev_set_drvdata(&pdev->dev, NULL);
}

static const struct of_device_id adp_of_match[] = {
	{ .compatible = "apple,h7-display-pipe", },
	{ },
};
MODULE_DEVICE_TABLE(of, adp_of_match);

static struct platform_driver adp_platform_driver = {
	.driver = {
		.name = "adp",
		.of_match_table = adp_of_match,
	},
	.probe = adp_probe,
	.remove = adp_remove,
};

module_platform_driver(adp_platform_driver);

MODULE_DESCRIPTION("Apple Display Pipe DRM driver");
MODULE_LICENSE("GPL");