/*
 * 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/module.h>
#include <linux/platform_device.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"
#include "ipuv3-plane.h"

#define MAX_CRTC        4

struct imx_drm_device {
        struct drm_device                       *drm;
        unsigned int                            pipes;
        struct drm_fbdev_cma                    *fbhelper;
        struct drm_atomic_state                 *state;
};

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

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);
}

DEFINE_DRM_GEM_CMA_FOPS(imx_drm_driver_fops);

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;

        /* Assign PRG/PRE channels and check if all constrains are satisfied. */
        ret = ipu_planes_assign_pre(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_plane *plane;
        struct drm_plane_state *old_plane_state, *new_plane_state;
        bool plane_disabling = false;
        int i;

        drm_atomic_helper_commit_modeset_disables(dev, state);

        drm_atomic_helper_commit_planes(dev, state,
                                DRM_PLANE_COMMIT_ACTIVE_ONLY |
                                DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET);

        drm_atomic_helper_commit_modeset_enables(dev, state);

        for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
                if (drm_atomic_plane_disabling(old_plane_state, new_plane_state))
                        plane_disabling = true;
        }

        if (plane_disabling) {
                drm_atomic_helper_wait_for_vblanks(dev, state);

                for_each_old_plane_in_state(state, plane, old_plane_state, i)
                        ipu_plane_disable_deferred(plane);

        }

        drm_atomic_helper_commit_hw_done(state);
}

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


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,
        .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,

        .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,
        .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)
{
        struct drm_device *drm;
        struct imx_drm_device *imxdrm;
        int ret;

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

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

        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 = 1;
        drm->mode_config.min_height = 1;
        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;

        dev_set_drvdata(dev, drm);

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

        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(dev, "Invalid legacyfb_depth.  Defaulting to 16bpp\n");
                legacyfb_depth = 16;
        }
        imxdrm->fbhelper = drm_fbdev_cma_init(drm, legacyfb_depth, 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);

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

        return 0;

err_fbhelper:
        drm_kms_helper_poll_fini(drm);
#if IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION)
        if (imxdrm->fbhelper)
                drm_fbdev_cma_fini(imxdrm->fbhelper);
err_unbind:
#endif
        component_unbind_all(drm->dev, drm);
err_kms:
        drm_mode_config_cleanup(drm);
err_unref:
        drm_dev_unref(drm);

        return ret;
}

static void imx_drm_unbind(struct device *dev)
{
        struct drm_device *drm = dev_get_drvdata(dev);
        struct imx_drm_device *imxdrm = drm->dev_private;

        drm_dev_unregister(drm);

        drm_kms_helper_poll_fini(drm);

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

        drm_mode_config_cleanup(drm);

        component_unbind_all(drm->dev, drm);
        dev_set_drvdata(dev, NULL);

        drm_dev_unref(drm);
}

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,
        },
};

static struct platform_driver * const drivers[] = {
        &imx_drm_pdrv,
        &ipu_drm_driver,
};

static int __init imx_drm_init(void)
{
        return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
}
module_init(imx_drm_init);

static void __exit imx_drm_exit(void)
{
        platform_unregister_drivers(drivers, ARRAY_SIZE(drivers));
}
module_exit(imx_drm_exit);

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