// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) Rockchip Electronics Co., Ltd.
 * Author:Mark Yao <mark.yao@rock-chips.com>
 *
 * based on exynos_drm_drv.c
 */

#include <linux/aperture.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/module.h>
#include <linux/of_graph.h>
#include <linux/of_platform.h>
#include <linux/component.h>
#include <linux/console.h>
#include <linux/iommu.h>

#include <drm/clients/drm_client_setup.h>
#include <drm/drm_drv.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_vblank.h>

#if defined(CONFIG_ARM_DMA_USE_IOMMU)
#include <asm/dma-iommu.h>
#else
#define arm_iommu_detach_device(...)    ({ })
#define arm_iommu_release_mapping(...)  ({ })
#define to_dma_iommu_mapping(dev) NULL
#endif

#include "rockchip_drm_drv.h"
#include "rockchip_drm_fb.h"
#include "rockchip_drm_gem.h"

#define DRIVER_NAME     "rockchip"
#define DRIVER_DESC     "RockChip Soc DRM"
#define DRIVER_MAJOR    1
#define DRIVER_MINOR    0

static const struct drm_driver rockchip_drm_driver;

/*
 * Attach a (component) device to the shared drm dma mapping from master drm
 * device.  This is used by the VOPs to map GEM buffers to a common DMA
 * mapping.
 */
int rockchip_drm_dma_attach_device(struct drm_device *drm_dev,
                                   struct device *dev)
{
        struct rockchip_drm_private *private = drm_dev->dev_private;
        int ret;

        if (!private->domain)
                return 0;

        if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
                struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);

                if (mapping) {
                        arm_iommu_detach_device(dev);
                        arm_iommu_release_mapping(mapping);
                }
        }

        ret = iommu_attach_device(private->domain, dev);
        if (ret) {
                DRM_DEV_ERROR(dev, "Failed to attach iommu device\n");
                return ret;
        }

        return 0;
}

void rockchip_drm_dma_detach_device(struct drm_device *drm_dev,
                                    struct device *dev)
{
        struct rockchip_drm_private *private = drm_dev->dev_private;

        if (!private->domain)
                return;

        iommu_detach_device(private->domain, dev);
}

void rockchip_drm_dma_init_device(struct drm_device *drm_dev,
                                  struct device *dev)
{
        struct rockchip_drm_private *private = drm_dev->dev_private;

        if (!device_iommu_mapped(dev))
                private->iommu_dev = ERR_PTR(-ENODEV);
        else if (!private->iommu_dev)
                private->iommu_dev = dev;

        if (!IS_ERR(private->iommu_dev))
                drm_dev_set_dma_dev(drm_dev, private->iommu_dev);
}

static int rockchip_drm_init_iommu(struct drm_device *drm_dev)
{
        struct rockchip_drm_private *private = drm_dev->dev_private;
        struct iommu_domain_geometry *geometry;
        u64 start, end;
        int ret;

        if (IS_ERR_OR_NULL(private->iommu_dev))
                return 0;

        private->domain = iommu_paging_domain_alloc(private->iommu_dev);
        if (IS_ERR(private->domain)) {
                ret = PTR_ERR(private->domain);
                private->domain = NULL;
                return ret;
        }

        geometry = &private->domain->geometry;
        start = geometry->aperture_start;
        end = geometry->aperture_end;

        DRM_DEBUG("IOMMU context initialized (aperture: %#llx-%#llx)\n",
                  start, end);
        drm_mm_init(&private->mm, start, end - start + 1);
        mutex_init(&private->mm_lock);

        return 0;
}

static void rockchip_iommu_cleanup(struct drm_device *drm_dev)
{
        struct rockchip_drm_private *private = drm_dev->dev_private;

        if (!private->domain)
                return;

        drm_mm_takedown(&private->mm);
        iommu_domain_free(private->domain);
}

static int rockchip_drm_bind(struct device *dev)
{
        struct drm_device *drm_dev;
        struct rockchip_drm_private *private;
        int ret;

        /* Remove existing drivers that may own the framebuffer memory. */
        ret = aperture_remove_all_conflicting_devices(rockchip_drm_driver.name);
        if (ret) {
                DRM_DEV_ERROR(dev,
                              "Failed to remove existing framebuffers - %d.\n",
                              ret);
                return ret;
        }

        drm_dev = drm_dev_alloc(&rockchip_drm_driver, dev);
        if (IS_ERR(drm_dev))
                return PTR_ERR(drm_dev);

        dev_set_drvdata(dev, drm_dev);

        private = devm_kzalloc(drm_dev->dev, sizeof(*private), GFP_KERNEL);
        if (!private) {
                ret = -ENOMEM;
                goto err_free;
        }

        drm_dev->dev_private = private;

        ret = drmm_mode_config_init(drm_dev);
        if (ret)
                goto err_free;

        rockchip_drm_mode_config_init(drm_dev);

        /* Try to bind all sub drivers. */
        ret = component_bind_all(dev, drm_dev);
        if (ret)
                goto err_free;

        ret = rockchip_drm_init_iommu(drm_dev);
        if (ret)
                goto err_unbind_all;

        ret = drm_vblank_init(drm_dev, drm_dev->mode_config.num_crtc);
        if (ret)
                goto err_iommu_cleanup;

        drm_mode_config_reset(drm_dev);

        /* init kms poll for handling hpd */
        drm_kms_helper_poll_init(drm_dev);

        ret = drm_dev_register(drm_dev, 0);
        if (ret)
                goto err_kms_helper_poll_fini;

        drm_client_setup(drm_dev, NULL);

        return 0;
err_kms_helper_poll_fini:
        drm_kms_helper_poll_fini(drm_dev);
err_iommu_cleanup:
        rockchip_iommu_cleanup(drm_dev);
err_unbind_all:
        component_unbind_all(dev, drm_dev);
err_free:
        drm_dev_put(drm_dev);
        return ret;
}

static void rockchip_drm_unbind(struct device *dev)
{
        struct drm_device *drm_dev = dev_get_drvdata(dev);

        drm_dev_unregister(drm_dev);

        drm_kms_helper_poll_fini(drm_dev);

        drm_atomic_helper_shutdown(drm_dev);
        component_unbind_all(dev, drm_dev);
        rockchip_iommu_cleanup(drm_dev);

        drm_dev_put(drm_dev);
}

DEFINE_DRM_GEM_FOPS(rockchip_drm_driver_fops);

static const struct drm_driver rockchip_drm_driver = {
        .driver_features        = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
        .dumb_create            = rockchip_gem_dumb_create,
        .gem_prime_import_sg_table      = rockchip_gem_prime_import_sg_table,
        DRM_FBDEV_DMA_DRIVER_OPS,
        .fops                   = &rockchip_drm_driver_fops,
        .name   = DRIVER_NAME,
        .desc   = DRIVER_DESC,
        .major  = DRIVER_MAJOR,
        .minor  = DRIVER_MINOR,
};

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

        return drm_mode_config_helper_suspend(drm);
}

static int rockchip_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 rockchip_drm_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(rockchip_drm_sys_suspend,
                                rockchip_drm_sys_resume)
};

#define MAX_ROCKCHIP_SUB_DRIVERS 16
static struct platform_driver *rockchip_sub_drivers[MAX_ROCKCHIP_SUB_DRIVERS];
static int num_rockchip_sub_drivers;

/*
 * Get the endpoint id of the remote endpoint of the given encoder. This
 * information is used by the VOP2 driver to identify the encoder.
 *
 * @rkencoder: The encoder to get the remote endpoint id from
 * @np: The encoder device node
 * @port: The number of the port leading to the VOP2
 * @reg: The endpoint number leading to the VOP2
 */
int rockchip_drm_encoder_set_crtc_endpoint_id(struct rockchip_encoder *rkencoder,
                                              struct device_node *np, int port, int reg)
{
        struct of_endpoint ep;
        struct device_node *en, *ren;
        int ret;

        en = of_graph_get_endpoint_by_regs(np, port, reg);
        if (!en)
                return -ENOENT;

        ren = of_graph_get_remote_endpoint(en);
        if (!ren)
                return -ENOENT;

        ret = of_graph_parse_endpoint(ren, &ep);
        if (ret)
                return ret;

        rkencoder->crtc_endpoint_id = ep.id;

        return 0;
}

/*
 * Check if a vop endpoint is leading to a rockchip subdriver or bridge.
 * Should be called from the component bind stage of the drivers
 * to ensure that all subdrivers are probed.
 *
 * @ep: endpoint of a rockchip vop
 *
 * returns true if subdriver, false if external bridge and -ENODEV
 * if remote port does not contain a device.
 */
int rockchip_drm_endpoint_is_subdriver(struct device_node *ep)
{
        struct device_node *node = of_graph_get_remote_port_parent(ep);
        struct platform_device *pdev;
        struct device_driver *drv;
        int i;

        if (!node)
                return -ENODEV;

        /* status disabled will prevent creation of platform-devices */
        if (!of_device_is_available(node)) {
                of_node_put(node);
                return -ENODEV;
        }

        pdev = of_find_device_by_node(node);
        of_node_put(node);

        /* enabled non-platform-devices can immediately return here */
        if (!pdev)
                return false;

        /*
         * All rockchip subdrivers have probed at this point, so
         * any device not having a driver now is an external bridge.
         */
        drv = pdev->dev.driver;
        if (!drv) {
                platform_device_put(pdev);
                return false;
        }

        for (i = 0; i < num_rockchip_sub_drivers; i++) {
                if (rockchip_sub_drivers[i] == to_platform_driver(drv)) {
                        platform_device_put(pdev);
                        return true;
                }
        }

        platform_device_put(pdev);
        return false;
}

static void rockchip_drm_match_remove(struct device *dev)
{
        struct device_link *link;

        list_for_each_entry(link, &dev->links.consumers, s_node)
                device_link_del(link);
}

/* list of preferred vop devices */
static const char *const rockchip_drm_match_preferred[] = {
        "rockchip,rk3399-vop-big",
        NULL,
};

static struct component_match *rockchip_drm_match_add(struct device *dev)
{
        struct component_match *match = NULL;
        struct device_node *port;
        int i;

        /* add preferred vop device match before adding driver device matches */
        for (i = 0; ; i++) {
                port = of_parse_phandle(dev->of_node, "ports", i);
                if (!port)
                        break;

                if (of_device_is_available(port->parent) &&
                    of_device_compatible_match(port->parent,
                                               rockchip_drm_match_preferred))
                        drm_of_component_match_add(dev, &match,
                                                   component_compare_of,
                                                   port->parent);

                of_node_put(port);
        }

        for (i = 0; i < num_rockchip_sub_drivers; i++) {
                struct platform_driver *drv = rockchip_sub_drivers[i];
                struct device *p = NULL, *d;

                do {
                        d = platform_find_device_by_driver(p, &drv->driver);
                        put_device(p);
                        p = d;

                        if (!d)
                                break;

                        device_link_add(dev, d, DL_FLAG_STATELESS);
                        component_match_add(dev, &match, component_compare_dev, d);
                } while (true);
        }

        if (IS_ERR(match))
                rockchip_drm_match_remove(dev);

        return match ?: ERR_PTR(-ENODEV);
}

static const struct component_master_ops rockchip_drm_ops = {
        .bind = rockchip_drm_bind,
        .unbind = rockchip_drm_unbind,
};

static int rockchip_drm_platform_of_probe(struct device *dev)
{
        struct device_node *np = dev->of_node;
        struct device_node *port;
        bool found = false;
        int i;

        if (!np)
                return -ENODEV;

        for (i = 0;; i++) {
                port = of_parse_phandle(np, "ports", i);
                if (!port)
                        break;

                if (!of_device_is_available(port->parent)) {
                        of_node_put(port);
                        continue;
                }

                found = true;
                of_node_put(port);
        }

        if (i == 0) {
                DRM_DEV_ERROR(dev, "missing 'ports' property\n");
                return -ENODEV;
        }

        if (!found) {
                DRM_DEV_ERROR(dev,
                              "No available vop found for display-subsystem.\n");
                return -ENODEV;
        }

        return 0;
}

static int rockchip_drm_platform_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct component_match *match = NULL;
        int ret;

        ret = rockchip_drm_platform_of_probe(dev);
        if (ret)
                return ret;

        match = rockchip_drm_match_add(dev);
        if (IS_ERR(match))
                return PTR_ERR(match);

        ret = component_master_add_with_match(dev, &rockchip_drm_ops, match);
        if (ret < 0) {
                rockchip_drm_match_remove(dev);
                return ret;
        }

        return 0;
}

static void rockchip_drm_platform_remove(struct platform_device *pdev)
{
        component_master_del(&pdev->dev, &rockchip_drm_ops);

        rockchip_drm_match_remove(&pdev->dev);
}

static void rockchip_drm_platform_shutdown(struct platform_device *pdev)
{
        if (component_master_is_bound(&pdev->dev, &rockchip_drm_ops)) {
                struct drm_device *drm = platform_get_drvdata(pdev);

                drm_atomic_helper_shutdown(drm);
        }
}

static const struct of_device_id rockchip_drm_dt_ids[] = {
        { .compatible = "rockchip,display-subsystem", },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, rockchip_drm_dt_ids);

static struct platform_driver rockchip_drm_platform_driver = {
        .probe = rockchip_drm_platform_probe,
        .remove = rockchip_drm_platform_remove,
        .shutdown = rockchip_drm_platform_shutdown,
        .driver = {
                .name = "rockchip-drm",
                .of_match_table = rockchip_drm_dt_ids,
                .pm = &rockchip_drm_pm_ops,
        },
};

#define ADD_ROCKCHIP_SUB_DRIVER(drv, cond) { \
        if (IS_ENABLED(cond) && \
            !WARN_ON(num_rockchip_sub_drivers >= MAX_ROCKCHIP_SUB_DRIVERS)) \
                rockchip_sub_drivers[num_rockchip_sub_drivers++] = &drv; \
}

static int __init rockchip_drm_init(void)
{
        int ret;

        if (drm_firmware_drivers_only())
                return -ENODEV;

        num_rockchip_sub_drivers = 0;
        ADD_ROCKCHIP_SUB_DRIVER(vop_platform_driver, CONFIG_ROCKCHIP_VOP);
        ADD_ROCKCHIP_SUB_DRIVER(vop2_platform_driver, CONFIG_ROCKCHIP_VOP2);
        ADD_ROCKCHIP_SUB_DRIVER(rockchip_lvds_driver,
                                CONFIG_ROCKCHIP_LVDS);
        ADD_ROCKCHIP_SUB_DRIVER(rockchip_dp_driver,
                                CONFIG_ROCKCHIP_ANALOGIX_DP);
        ADD_ROCKCHIP_SUB_DRIVER(cdn_dp_driver, CONFIG_ROCKCHIP_CDN_DP);
        ADD_ROCKCHIP_SUB_DRIVER(dw_dp_driver, CONFIG_ROCKCHIP_DW_DP);
        ADD_ROCKCHIP_SUB_DRIVER(dw_hdmi_rockchip_pltfm_driver,
                                CONFIG_ROCKCHIP_DW_HDMI);
        ADD_ROCKCHIP_SUB_DRIVER(dw_hdmi_qp_rockchip_pltfm_driver,
                                CONFIG_ROCKCHIP_DW_HDMI_QP);
        ADD_ROCKCHIP_SUB_DRIVER(dw_mipi_dsi_rockchip_driver,
                                CONFIG_ROCKCHIP_DW_MIPI_DSI);
        ADD_ROCKCHIP_SUB_DRIVER(dw_mipi_dsi2_rockchip_driver,
                                CONFIG_ROCKCHIP_DW_MIPI_DSI2);
        ADD_ROCKCHIP_SUB_DRIVER(inno_hdmi_driver, CONFIG_ROCKCHIP_INNO_HDMI);
        ADD_ROCKCHIP_SUB_DRIVER(rk3066_hdmi_driver,
                                CONFIG_ROCKCHIP_RK3066_HDMI);

        ret = platform_register_drivers(rockchip_sub_drivers,
                                        num_rockchip_sub_drivers);
        if (ret)
                return ret;

        ret = platform_driver_register(&rockchip_drm_platform_driver);
        if (ret)
                goto err_unreg_drivers;

        return 0;

err_unreg_drivers:
        platform_unregister_drivers(rockchip_sub_drivers,
                                    num_rockchip_sub_drivers);
        return ret;
}

static void __exit rockchip_drm_fini(void)
{
        platform_driver_unregister(&rockchip_drm_platform_driver);

        platform_unregister_drivers(rockchip_sub_drivers,
                                    num_rockchip_sub_drivers);
}

module_init(rockchip_drm_init);
module_exit(rockchip_drm_fini);

MODULE_AUTHOR("Mark Yao <mark.yao@rock-chips.com>");
MODULE_DESCRIPTION("ROCKCHIP DRM Driver");
MODULE_LICENSE("GPL v2");