// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2015 Free Electrons
 * Copyright (C) 2015 NextThing Co
 *
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 */

#include <linux/aperture.h>
#include <linux/component.h>
#include <linux/dma-mapping.h>
#include <linux/kfifo.h>
#include <linux/module.h>
#include <linux/of_graph.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.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_dma_helper.h>
#include <drm/drm_module.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_vblank.h>

#include "sun4i_drv.h"
#include "sun4i_frontend.h"
#include "sun4i_framebuffer.h"
#include "sun4i_tcon.h"
#include "sun8i_tcon_top.h"

static int drm_sun4i_gem_dumb_create(struct drm_file *file_priv,
                                     struct drm_device *drm,
                                     struct drm_mode_create_dumb *args)
{
        /* The hardware only allows even pitches for YUV buffers. */
        args->pitch = ALIGN(DIV_ROUND_UP(args->width * args->bpp, 8), 2);

        return drm_gem_dma_dumb_create_internal(file_priv, drm, args);
}

DEFINE_DRM_GEM_DMA_FOPS(sun4i_drv_fops);

static const struct drm_driver sun4i_drv_driver = {
        .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,

        /* Generic Operations */
        .fops                   = &sun4i_drv_fops,
        .name                   = "sun4i-drm",
        .desc                   = "Allwinner sun4i Display Engine",
        .major                  = 1,
        .minor                  = 0,

        /* GEM Operations */
        DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE(drm_sun4i_gem_dumb_create),
        DRM_FBDEV_DMA_DRIVER_OPS,
};

static int sun4i_drv_bind(struct device *dev)
{
        struct drm_device *drm;
        struct sun4i_drv *drv;
        int ret;

        drm = drm_dev_alloc(&sun4i_drv_driver, dev);
        if (IS_ERR(drm))
                return PTR_ERR(drm);

        drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
        if (!drv) {
                ret = -ENOMEM;
                goto free_drm;
        }

        drm->dev_private = drv;
        INIT_LIST_HEAD(&drv->frontend_list);
        INIT_LIST_HEAD(&drv->engine_list);
        INIT_LIST_HEAD(&drv->tcon_list);

        ret = of_reserved_mem_device_init(dev);
        if (ret && ret != -ENODEV) {
                dev_err(drm->dev, "Couldn't claim our memory region\n");
                goto free_drm;
        }

        drm_mode_config_init(drm);

        ret = component_bind_all(drm->dev, drm);
        if (ret) {
                dev_err(drm->dev, "Couldn't bind all pipelines components\n");
                goto cleanup_mode_config;
        }

        /* drm_vblank_init calls kcalloc, which can fail */
        ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
        if (ret)
                goto unbind_all;

        /* Remove early framebuffers (ie. simplefb) */
        ret = aperture_remove_all_conflicting_devices(sun4i_drv_driver.name);
        if (ret)
                goto unbind_all;

        sun4i_framebuffer_init(drm);

        /* Enable connectors polling */
        drm_kms_helper_poll_init(drm);

        ret = drm_dev_register(drm, 0);
        if (ret)
                goto finish_poll;

        drm_client_setup(drm, NULL);

        dev_set_drvdata(dev, drm);

        return 0;

finish_poll:
        drm_kms_helper_poll_fini(drm);
unbind_all:
        component_unbind_all(dev, NULL);
cleanup_mode_config:
        drm_mode_config_cleanup(drm);
        of_reserved_mem_device_release(dev);
free_drm:
        drm_dev_put(drm);
        return ret;
}

static void sun4i_drv_unbind(struct device *dev)
{
        struct drm_device *drm = dev_get_drvdata(dev);

        dev_set_drvdata(dev, NULL);
        drm_dev_unregister(drm);
        drm_kms_helper_poll_fini(drm);
        drm_atomic_helper_shutdown(drm);
        drm_mode_config_cleanup(drm);

        component_unbind_all(dev, NULL);
        of_reserved_mem_device_release(dev);

        drm_dev_put(drm);
}

static const struct component_master_ops sun4i_drv_master_ops = {
        .bind   = sun4i_drv_bind,
        .unbind = sun4i_drv_unbind,
};

static bool sun4i_drv_node_is_connector(struct device_node *node)
{
        return of_device_is_compatible(node, "hdmi-connector");
}

static bool sun4i_drv_node_is_frontend(struct device_node *node)
{
        return of_device_is_compatible(node, "allwinner,sun4i-a10-display-frontend") ||
                of_device_is_compatible(node, "allwinner,sun5i-a13-display-frontend") ||
                of_device_is_compatible(node, "allwinner,sun6i-a31-display-frontend") ||
                of_device_is_compatible(node, "allwinner,sun7i-a20-display-frontend") ||
                of_device_is_compatible(node, "allwinner,sun8i-a23-display-frontend") ||
                of_device_is_compatible(node, "allwinner,sun8i-a33-display-frontend") ||
                of_device_is_compatible(node, "allwinner,sun9i-a80-display-frontend");
}

static bool sun4i_drv_node_is_deu(struct device_node *node)
{
        return of_device_is_compatible(node, "allwinner,sun9i-a80-deu");
}

static bool sun4i_drv_node_is_supported_frontend(struct device_node *node)
{
        if (IS_ENABLED(CONFIG_DRM_SUN4I_BACKEND))
                return !!of_match_node(sun4i_frontend_of_table, node);

        return false;
}

static bool sun4i_drv_node_is_tcon(struct device_node *node)
{
        return !!of_match_node(sun4i_tcon_of_table, node);
}

static bool sun4i_drv_node_is_tcon_with_ch0(struct device_node *node)
{
        const struct of_device_id *match;

        match = of_match_node(sun4i_tcon_of_table, node);
        if (match) {
                struct sun4i_tcon_quirks *quirks;

                quirks = (struct sun4i_tcon_quirks *)match->data;

                return quirks->has_channel_0;
        }

        return false;
}

static bool sun4i_drv_node_is_tcon_top(struct device_node *node)
{
        return IS_ENABLED(CONFIG_DRM_SUN8I_TCON_TOP) &&
                !!of_match_node(sun8i_tcon_top_of_table, node);
}

/*
 * The encoder drivers use drm_of_find_possible_crtcs to get upstream
 * crtcs from the device tree using of_graph. For the results to be
 * correct, encoders must be probed/bound after _all_ crtcs have been
 * created. The existing code uses a depth first recursive traversal
 * of the of_graph, which means the encoders downstream of the TCON
 * get add right after the first TCON. The second TCON or CRTC will
 * never be properly associated with encoders connected to it.
 *
 * Also, in a dual display pipeline setup, both frontends can feed
 * either backend, and both backends can feed either TCON, we want
 * all components of the same type to be added before the next type
 * in the pipeline. Fortunately, the pipelines are perfectly symmetric,
 * i.e. components of the same type are at the same depth when counted
 * from the frontend. The only exception is the third pipeline in
 * the A80 SoC, which we do not support anyway.
 *
 * Hence we can use a breadth first search traversal order to add
 * components. We do not need to check for duplicates. The component
 * matching system handles this for us.
 */
struct endpoint_list {
        DECLARE_KFIFO(fifo, struct device_node *, 16);
};

static void sun4i_drv_traverse_endpoints(struct endpoint_list *list,
                                         struct device_node *node,
                                         int port_id)
{
        struct device_node *ep, *remote, *port;

        port = of_graph_get_port_by_id(node, port_id);
        if (!port) {
                DRM_DEBUG_DRIVER("No output to bind on port %d\n", port_id);
                return;
        }

        for_each_available_child_of_node(port, ep) {
                remote = of_graph_get_remote_port_parent(ep);
                if (!remote) {
                        DRM_DEBUG_DRIVER("Error retrieving the output node\n");
                        continue;
                }

                if (sun4i_drv_node_is_tcon(node)) {
                        /*
                         * TCON TOP is always probed before TCON. However, TCON
                         * points back to TCON TOP when it is source for HDMI.
                         * We have to skip it here to prevent infinite looping
                         * between TCON TOP and TCON.
                         */
                        if (sun4i_drv_node_is_tcon_top(remote)) {
                                DRM_DEBUG_DRIVER("TCON output endpoint is TCON TOP... skipping\n");
                                of_node_put(remote);
                                continue;
                        }

                        /*
                         * If the node is our TCON with channel 0, the first
                         * port is used for panel or bridges, and will not be
                         * part of the component framework.
                         */
                        if (sun4i_drv_node_is_tcon_with_ch0(node)) {
                                struct of_endpoint endpoint;

                                if (of_graph_parse_endpoint(ep, &endpoint)) {
                                        DRM_DEBUG_DRIVER("Couldn't parse endpoint\n");
                                        of_node_put(remote);
                                        continue;
                                }

                                if (!endpoint.id) {
                                        DRM_DEBUG_DRIVER("Endpoint is our panel... skipping\n");
                                        of_node_put(remote);
                                        continue;
                                }
                        }
                }

                kfifo_put(&list->fifo, remote);
        }
}

static int sun4i_drv_add_endpoints(struct device *dev,
                                   struct endpoint_list *list,
                                   struct component_match **match,
                                   struct device_node *node)
{
        int count = 0;

        /*
         * The frontend has been disabled in some of our old device
         * trees. If we find a node that is the frontend and is
         * disabled, we should just follow through and parse its
         * child, but without adding it to the component list.
         * Otherwise, we obviously want to add it to the list.
         */
        if (!sun4i_drv_node_is_frontend(node) &&
            !of_device_is_available(node))
                return 0;

        /*
         * The connectors will be the last nodes in our pipeline, we
         * can just bail out.
         */
        if (sun4i_drv_node_is_connector(node))
                return 0;

        /*
         * If the device is either just a regular device, or an
         * enabled frontend supported by the driver, we add it to our
         * component list.
         */
        if (!(sun4i_drv_node_is_frontend(node) ||
              sun4i_drv_node_is_deu(node)) ||
            (sun4i_drv_node_is_supported_frontend(node) &&
             of_device_is_available(node))) {
                /* Add current component */
                DRM_DEBUG_DRIVER("Adding component %pOF\n", node);
                drm_of_component_match_add(dev, match, component_compare_of, node);
                count++;
        }

        /* each node has at least one output */
        sun4i_drv_traverse_endpoints(list, node, 1);

        /* TCON TOP has second and third output */
        if (sun4i_drv_node_is_tcon_top(node)) {
                sun4i_drv_traverse_endpoints(list, node, 3);
                sun4i_drv_traverse_endpoints(list, node, 5);
        }

        return count;
}

#ifdef CONFIG_PM_SLEEP
static int sun4i_drv_drm_sys_suspend(struct device *dev)
{
        struct drm_device *drm = dev_get_drvdata(dev);

        return drm_mode_config_helper_suspend(drm);
}

static int sun4i_drv_drm_sys_resume(struct device *dev)
{
        struct drm_device *drm = dev_get_drvdata(dev);

        return drm_mode_config_helper_resume(drm);
}
#endif

static const struct dev_pm_ops sun4i_drv_drm_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(sun4i_drv_drm_sys_suspend,
                                sun4i_drv_drm_sys_resume)
};

static int sun4i_drv_probe(struct platform_device *pdev)
{
        struct component_match *match = NULL;
        struct device_node *np = pdev->dev.of_node, *endpoint;
        struct endpoint_list list;
        int i, ret, count = 0;

        INIT_KFIFO(list.fifo);

        /*
         * DE2 and DE3 cores actually supports 40-bit addresses, but
         * driver does not.
         */
        dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
        dma_set_max_seg_size(&pdev->dev, UINT_MAX);

        for (i = 0;; i++) {
                struct device_node *pipeline = of_parse_phandle(np,
                                                                "allwinner,pipelines",
                                                                i);
                if (!pipeline)
                        break;

                kfifo_put(&list.fifo, pipeline);
        }

        while (kfifo_get(&list.fifo, &endpoint)) {
                /* process this endpoint */
                ret = sun4i_drv_add_endpoints(&pdev->dev, &list, &match,
                                              endpoint);

                /* sun4i_drv_add_endpoints can fail to allocate memory */
                if (ret < 0)
                        return ret;

                count += ret;
        }

        if (count)
                return component_master_add_with_match(&pdev->dev,
                                                       &sun4i_drv_master_ops,
                                                       match);
        else
                return 0;
}

static void sun4i_drv_remove(struct platform_device *pdev)
{
        component_master_del(&pdev->dev, &sun4i_drv_master_ops);
}

static void sun4i_drv_shutdown(struct platform_device *pdev)
{
        drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
}

static const struct of_device_id sun4i_drv_of_table[] = {
        { .compatible = "allwinner,sun4i-a10-display-engine" },
        { .compatible = "allwinner,sun5i-a10s-display-engine" },
        { .compatible = "allwinner,sun5i-a13-display-engine" },
        { .compatible = "allwinner,sun6i-a31-display-engine" },
        { .compatible = "allwinner,sun6i-a31s-display-engine" },
        { .compatible = "allwinner,sun7i-a20-display-engine" },
        { .compatible = "allwinner,sun8i-a23-display-engine" },
        { .compatible = "allwinner,sun8i-a33-display-engine" },
        { .compatible = "allwinner,sun8i-a83t-display-engine" },
        { .compatible = "allwinner,sun8i-h3-display-engine" },
        { .compatible = "allwinner,sun8i-r40-display-engine" },
        { .compatible = "allwinner,sun8i-v3s-display-engine" },
        { .compatible = "allwinner,sun9i-a80-display-engine" },
        { .compatible = "allwinner,sun20i-d1-display-engine" },
        { .compatible = "allwinner,sun50i-a64-display-engine" },
        { .compatible = "allwinner,sun50i-h6-display-engine" },
        { }
};
MODULE_DEVICE_TABLE(of, sun4i_drv_of_table);

static struct platform_driver sun4i_drv_platform_driver = {
        .probe          = sun4i_drv_probe,
        .remove         = sun4i_drv_remove,
        .shutdown       = sun4i_drv_shutdown,
        .driver         = {
                .name           = "sun4i-drm",
                .of_match_table = sun4i_drv_of_table,
                .pm = &sun4i_drv_drm_pm_ops,
        },
};
drm_module_platform_driver(sun4i_drv_platform_driver);

MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
MODULE_DESCRIPTION("Allwinner A10 Display Engine DRM/KMS Driver");
MODULE_LICENSE("GPL");