/*
 * Freescale i.MX drm driver
 *
 * Copyright (C) 2011 Sascha Hauer, Pengutronix
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */
#include <linux/component.h>
#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/fb.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/reservation.h>
#include <drm/drmP.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_of.h>
#include <video/imx-ipu-v3.h>

#include "imx-drm.h"

#define MAX_CRTC        4

struct imx_drm_component {
        struct device_node *of_node;
        struct list_head list;
};

struct imx_drm_device {
        struct drm_device                       *drm;
        struct imx_drm_crtc                     *crtc[MAX_CRTC];
        unsigned int                            pipes;
        struct drm_fbdev_cma                    *fbhelper;
        struct drm_atomic_state                 *state;
};

struct imx_drm_crtc {
        struct drm_crtc                         *crtc;
        struct imx_drm_crtc_helper_funcs        imx_drm_helper_funcs;
};

#if IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION)
static int legacyfb_depth = 16;
module_param(legacyfb_depth, int, 0444);
#endif

unsigned int imx_drm_crtc_id(struct imx_drm_crtc *crtc)
{
        return drm_crtc_index(crtc->crtc);
}
EXPORT_SYMBOL_GPL(imx_drm_crtc_id);

static void imx_drm_driver_lastclose(struct drm_device *drm)
{
        struct imx_drm_device *imxdrm = drm->dev_private;

        drm_fbdev_cma_restore_mode(imxdrm->fbhelper);
}

static int imx_drm_driver_unload(struct drm_device *drm)
{
        struct imx_drm_device *imxdrm = drm->dev_private;

        drm_kms_helper_poll_fini(drm);

        if (imxdrm->fbhelper)
                drm_fbdev_cma_fini(imxdrm->fbhelper);

        component_unbind_all(drm->dev, drm);

        drm_vblank_cleanup(drm);
        drm_mode_config_cleanup(drm);

        platform_set_drvdata(drm->platformdev, NULL);

        return 0;
}

int imx_drm_crtc_vblank_get(struct imx_drm_crtc *imx_drm_crtc)
{
        return drm_crtc_vblank_get(imx_drm_crtc->crtc);
}
EXPORT_SYMBOL_GPL(imx_drm_crtc_vblank_get);

void imx_drm_crtc_vblank_put(struct imx_drm_crtc *imx_drm_crtc)
{
        drm_crtc_vblank_put(imx_drm_crtc->crtc);
}
EXPORT_SYMBOL_GPL(imx_drm_crtc_vblank_put);

void imx_drm_handle_vblank(struct imx_drm_crtc *imx_drm_crtc)
{
        drm_crtc_handle_vblank(imx_drm_crtc->crtc);
}
EXPORT_SYMBOL_GPL(imx_drm_handle_vblank);

static int imx_drm_enable_vblank(struct drm_device *drm, unsigned int pipe)
{
        struct imx_drm_device *imxdrm = drm->dev_private;
        struct imx_drm_crtc *imx_drm_crtc = imxdrm->crtc[pipe];
        int ret;

        if (!imx_drm_crtc)
                return -EINVAL;

        if (!imx_drm_crtc->imx_drm_helper_funcs.enable_vblank)
                return -ENOSYS;

        ret = imx_drm_crtc->imx_drm_helper_funcs.enable_vblank(
                        imx_drm_crtc->crtc);

        return ret;
}

static void imx_drm_disable_vblank(struct drm_device *drm, unsigned int pipe)
{
        struct imx_drm_device *imxdrm = drm->dev_private;
        struct imx_drm_crtc *imx_drm_crtc = imxdrm->crtc[pipe];

        if (!imx_drm_crtc)
                return;

        if (!imx_drm_crtc->imx_drm_helper_funcs.disable_vblank)
                return;

        imx_drm_crtc->imx_drm_helper_funcs.disable_vblank(imx_drm_crtc->crtc);
}

static const struct file_operations imx_drm_driver_fops = {
        .owner = THIS_MODULE,
        .open = drm_open,
        .release = drm_release,
        .unlocked_ioctl = drm_ioctl,
        .mmap = drm_gem_cma_mmap,
        .poll = drm_poll,
        .read = drm_read,
        .llseek = noop_llseek,
};

void imx_drm_connector_destroy(struct drm_connector *connector)
{
        drm_connector_unregister(connector);
        drm_connector_cleanup(connector);
}
EXPORT_SYMBOL_GPL(imx_drm_connector_destroy);

void imx_drm_encoder_destroy(struct drm_encoder *encoder)
{
        drm_encoder_cleanup(encoder);
}
EXPORT_SYMBOL_GPL(imx_drm_encoder_destroy);

static void imx_drm_output_poll_changed(struct drm_device *drm)
{
        struct imx_drm_device *imxdrm = drm->dev_private;

        drm_fbdev_cma_hotplug_event(imxdrm->fbhelper);
}

static int imx_drm_atomic_check(struct drm_device *dev,
                                struct drm_atomic_state *state)
{
        int ret;

        ret = drm_atomic_helper_check_modeset(dev, state);
        if (ret)
                return ret;

        ret = drm_atomic_helper_check_planes(dev, state);
        if (ret)
                return ret;

        /*
         * Check modeset again in case crtc_state->mode_changed is
         * updated in plane's ->atomic_check callback.
         */
        ret = drm_atomic_helper_check_modeset(dev, state);
        if (ret)
                return ret;

        return ret;
}

static const struct drm_mode_config_funcs imx_drm_mode_config_funcs = {
        .fb_create = drm_fb_cma_create,
        .output_poll_changed = imx_drm_output_poll_changed,
        .atomic_check = imx_drm_atomic_check,
        .atomic_commit = drm_atomic_helper_commit,
};

static void imx_drm_atomic_commit_tail(struct drm_atomic_state *state)
{
        struct drm_device *dev = state->dev;
        struct drm_crtc *crtc;
        struct drm_crtc_state *crtc_state;
        struct drm_plane_state *plane_state;
        struct drm_gem_cma_object *cma_obj;
        struct fence *excl;
        unsigned shared_count;
        struct fence **shared;
        unsigned int i, j;
        int ret;

        /* Wait for fences. */
        for_each_crtc_in_state(state, crtc, crtc_state, i) {
                plane_state = crtc->primary->state;
                if (plane_state->fb) {
                        cma_obj = drm_fb_cma_get_gem_obj(plane_state->fb, 0);
                        if (cma_obj->base.dma_buf) {
                                ret = reservation_object_get_fences_rcu(
                                        cma_obj->base.dma_buf->resv, &excl,
                                        &shared_count, &shared);
                                if (unlikely(ret))
                                        DRM_ERROR("failed to get fences "
                                                  "for buffer\n");

                                if (excl) {
                                        fence_wait(excl, false);
                                        fence_put(excl);
                                }
                                for (j = 0; j < shared_count; i++) {
                                        fence_wait(shared[j], false);
                                        fence_put(shared[j]);
                                }
                        }
                }
        }

        drm_atomic_helper_commit_modeset_disables(dev, state);

        drm_atomic_helper_commit_planes(dev, state, true);

        drm_atomic_helper_commit_modeset_enables(dev, state);

        drm_atomic_helper_commit_hw_done(state);

        drm_atomic_helper_wait_for_vblanks(dev, state);

        drm_atomic_helper_cleanup_planes(dev, state);
}

static struct drm_mode_config_helper_funcs imx_drm_mode_config_helpers = {
        .atomic_commit_tail = imx_drm_atomic_commit_tail,
};

/*
 * Main DRM initialisation. This binds, initialises and registers
 * with DRM the subcomponents of the driver.
 */
static int imx_drm_driver_load(struct drm_device *drm, unsigned long flags)
{
        struct imx_drm_device *imxdrm;
        struct drm_connector *connector;
        int ret;

        imxdrm = devm_kzalloc(drm->dev, sizeof(*imxdrm), GFP_KERNEL);
        if (!imxdrm)
                return -ENOMEM;

        imxdrm->drm = drm;

        drm->dev_private = imxdrm;

        /*
         * enable drm irq mode.
         * - with irq_enabled = true, we can use the vblank feature.
         *
         * P.S. note that we wouldn't use drm irq handler but
         *      just specific driver own one instead because
         *      drm framework supports only one irq handler and
         *      drivers can well take care of their interrupts
         */
        drm->irq_enabled = true;

        /*
         * set max width and height as default value(4096x4096).
         * this value would be used to check framebuffer size limitation
         * at drm_mode_addfb().
         */
        drm->mode_config.min_width = 64;
        drm->mode_config.min_height = 64;
        drm->mode_config.max_width = 4096;
        drm->mode_config.max_height = 4096;
        drm->mode_config.funcs = &imx_drm_mode_config_funcs;
        drm->mode_config.helper_private = &imx_drm_mode_config_helpers;

        drm_mode_config_init(drm);

        ret = drm_vblank_init(drm, MAX_CRTC);
        if (ret)
                goto err_kms;

        platform_set_drvdata(drm->platformdev, drm);

        /* Now try and bind all our sub-components */
        ret = component_bind_all(drm->dev, drm);
        if (ret)
                goto err_vblank;

        /*
         * All components are now added, we can publish the connector sysfs
         * entries to userspace.  This will generate hotplug events and so
         * userspace will expect to be able to access DRM at this point.
         */
        list_for_each_entry(connector, &drm->mode_config.connector_list, head) {
                ret = drm_connector_register(connector);
                if (ret) {
                        dev_err(drm->dev,
                                "[CONNECTOR:%d:%s] drm_connector_register failed: %d\n",
                                connector->base.id,
                                connector->name, ret);
                        goto err_unbind;
                }
        }

        drm_mode_config_reset(drm);

        /*
         * All components are now initialised, so setup the fb helper.
         * The fb helper takes copies of key hardware information, so the
         * crtcs/connectors/encoders must not change after this point.
         */
#if IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION)
        if (legacyfb_depth != 16 && legacyfb_depth != 32) {
                dev_warn(drm->dev, "Invalid legacyfb_depth.  Defaulting to 16bpp\n");
                legacyfb_depth = 16;
        }
        imxdrm->fbhelper = drm_fbdev_cma_init(drm, legacyfb_depth,
                                drm->mode_config.num_crtc, MAX_CRTC);
        if (IS_ERR(imxdrm->fbhelper)) {
                ret = PTR_ERR(imxdrm->fbhelper);
                imxdrm->fbhelper = NULL;
                goto err_unbind;
        }
#endif

        drm_kms_helper_poll_init(drm);

        return 0;

err_unbind:
        component_unbind_all(drm->dev, drm);
err_vblank:
        drm_vblank_cleanup(drm);
err_kms:
        drm_mode_config_cleanup(drm);

        return ret;
}

/*
 * imx_drm_add_crtc - add a new crtc
 */
int imx_drm_add_crtc(struct drm_device *drm, struct drm_crtc *crtc,
                struct imx_drm_crtc **new_crtc, struct drm_plane *primary_plane,
                const struct imx_drm_crtc_helper_funcs *imx_drm_helper_funcs,
                struct device_node *port)
{
        struct imx_drm_device *imxdrm = drm->dev_private;
        struct imx_drm_crtc *imx_drm_crtc;

        /*
         * The vblank arrays are dimensioned by MAX_CRTC - we can't
         * pass IDs greater than this to those functions.
         */
        if (imxdrm->pipes >= MAX_CRTC)
                return -EINVAL;

        if (imxdrm->drm->open_count)
                return -EBUSY;

        imx_drm_crtc = kzalloc(sizeof(*imx_drm_crtc), GFP_KERNEL);
        if (!imx_drm_crtc)
                return -ENOMEM;

        imx_drm_crtc->imx_drm_helper_funcs = *imx_drm_helper_funcs;
        imx_drm_crtc->crtc = crtc;

        crtc->port = port;

        imxdrm->crtc[imxdrm->pipes++] = imx_drm_crtc;

        *new_crtc = imx_drm_crtc;

        drm_crtc_helper_add(crtc,
                        imx_drm_crtc->imx_drm_helper_funcs.crtc_helper_funcs);

        drm_crtc_init_with_planes(drm, crtc, primary_plane, NULL,
                        imx_drm_crtc->imx_drm_helper_funcs.crtc_funcs, NULL);

        return 0;
}
EXPORT_SYMBOL_GPL(imx_drm_add_crtc);

/*
 * imx_drm_remove_crtc - remove a crtc
 */
int imx_drm_remove_crtc(struct imx_drm_crtc *imx_drm_crtc)
{
        struct imx_drm_device *imxdrm = imx_drm_crtc->crtc->dev->dev_private;
        unsigned int pipe = drm_crtc_index(imx_drm_crtc->crtc);

        drm_crtc_cleanup(imx_drm_crtc->crtc);

        imxdrm->crtc[pipe] = NULL;

        kfree(imx_drm_crtc);

        return 0;
}
EXPORT_SYMBOL_GPL(imx_drm_remove_crtc);

int imx_drm_encoder_parse_of(struct drm_device *drm,
        struct drm_encoder *encoder, struct device_node *np)
{
        uint32_t crtc_mask = drm_of_find_possible_crtcs(drm, np);

        /*
         * If we failed to find the CRTC(s) which this encoder is
         * supposed to be connected to, it's because the CRTC has
         * not been registered yet.  Defer probing, and hope that
         * the required CRTC is added later.
         */
        if (crtc_mask == 0)
                return -EPROBE_DEFER;

        encoder->possible_crtcs = crtc_mask;

        /* FIXME: this is the mask of outputs which can clone this output. */
        encoder->possible_clones = ~0;

        return 0;
}
EXPORT_SYMBOL_GPL(imx_drm_encoder_parse_of);

static const struct drm_ioctl_desc imx_drm_ioctls[] = {
        /* none so far */
};

static struct drm_driver imx_drm_driver = {
        .driver_features        = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
                                  DRIVER_ATOMIC,
        .load                   = imx_drm_driver_load,
        .unload                 = imx_drm_driver_unload,
        .lastclose              = imx_drm_driver_lastclose,
        .gem_free_object_unlocked = drm_gem_cma_free_object,
        .gem_vm_ops             = &drm_gem_cma_vm_ops,
        .dumb_create            = drm_gem_cma_dumb_create,
        .dumb_map_offset        = drm_gem_cma_dumb_map_offset,
        .dumb_destroy           = drm_gem_dumb_destroy,

        .prime_handle_to_fd     = drm_gem_prime_handle_to_fd,
        .prime_fd_to_handle     = drm_gem_prime_fd_to_handle,
        .gem_prime_import       = drm_gem_prime_import,
        .gem_prime_export       = drm_gem_prime_export,
        .gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
        .gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
        .gem_prime_vmap         = drm_gem_cma_prime_vmap,
        .gem_prime_vunmap       = drm_gem_cma_prime_vunmap,
        .gem_prime_mmap         = drm_gem_cma_prime_mmap,
        .get_vblank_counter     = drm_vblank_no_hw_counter,
        .enable_vblank          = imx_drm_enable_vblank,
        .disable_vblank         = imx_drm_disable_vblank,
        .ioctls                 = imx_drm_ioctls,
        .num_ioctls             = ARRAY_SIZE(imx_drm_ioctls),
        .fops                   = &imx_drm_driver_fops,
        .name                   = "imx-drm",
        .desc                   = "i.MX DRM graphics",
        .date                   = "20120507",
        .major                  = 1,
        .minor                  = 0,
        .patchlevel             = 0,
};

static int compare_of(struct device *dev, void *data)
{
        struct device_node *np = data;

        /* Special case for DI, dev->of_node may not be set yet */
        if (strcmp(dev->driver->name, "imx-ipuv3-crtc") == 0) {
                struct ipu_client_platformdata *pdata = dev->platform_data;

                return pdata->of_node == np;
        }

        /* Special case for LDB, one device for two channels */
        if (of_node_cmp(np->name, "lvds-channel") == 0) {
                np = of_get_parent(np);
                of_node_put(np);
        }

        return dev->of_node == np;
}

static int imx_drm_bind(struct device *dev)
{
        return drm_platform_init(&imx_drm_driver, to_platform_device(dev));
}

static void imx_drm_unbind(struct device *dev)
{
        drm_put_dev(dev_get_drvdata(dev));
}

static const struct component_master_ops imx_drm_ops = {
        .bind = imx_drm_bind,
        .unbind = imx_drm_unbind,
};

static int imx_drm_platform_probe(struct platform_device *pdev)
{
        int ret = drm_of_component_probe(&pdev->dev, compare_of, &imx_drm_ops);

        if (!ret)
                ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));

        return ret;
}

static int imx_drm_platform_remove(struct platform_device *pdev)
{
        component_master_del(&pdev->dev, &imx_drm_ops);
        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int imx_drm_suspend(struct device *dev)
{
        struct drm_device *drm_dev = dev_get_drvdata(dev);
        struct imx_drm_device *imxdrm;

        /* The drm_dev is NULL before .load hook is called */
        if (drm_dev == NULL)
                return 0;

        drm_kms_helper_poll_disable(drm_dev);

        imxdrm = drm_dev->dev_private;
        imxdrm->state = drm_atomic_helper_suspend(drm_dev);
        if (IS_ERR(imxdrm->state)) {
                drm_kms_helper_poll_enable(drm_dev);
                return PTR_ERR(imxdrm->state);
        }

        return 0;
}

static int imx_drm_resume(struct device *dev)
{
        struct drm_device *drm_dev = dev_get_drvdata(dev);
        struct imx_drm_device *imx_drm;

        if (drm_dev == NULL)
                return 0;

        imx_drm = drm_dev->dev_private;
        drm_atomic_helper_resume(drm_dev, imx_drm->state);
        drm_kms_helper_poll_enable(drm_dev);

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(imx_drm_pm_ops, imx_drm_suspend, imx_drm_resume);

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

static struct platform_driver imx_drm_pdrv = {
        .probe          = imx_drm_platform_probe,
        .remove         = imx_drm_platform_remove,
        .driver         = {
                .name   = "imx-drm",
                .pm     = &imx_drm_pm_ops,
                .of_match_table = imx_drm_dt_ids,
        },
};
module_platform_driver(imx_drm_pdrv);

MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
MODULE_DESCRIPTION("i.MX drm driver core");
MODULE_LICENSE("GPL");