/*
 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
 * Author: Rob Clark <rob@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/of.h>
#include <linux/sort.h>
#include <linux/sys_soc.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>

#include "omap_dmm_tiler.h"
#include "omap_drv.h"

#define DRIVER_NAME             MODULE_NAME
#define DRIVER_DESC             "OMAP DRM"
#define DRIVER_DATE             "20110917"
#define DRIVER_MAJOR            1
#define DRIVER_MINOR            0
#define DRIVER_PATCHLEVEL       0

/*
 * mode config funcs
 */

/* Notes about mapping DSS and DRM entities:
 *    CRTC:        overlay
 *    encoder:     manager.. with some extension to allow one primary CRTC
 *                 and zero or more video CRTC's to be mapped to one encoder?
 *    connector:   dssdev.. manager can be attached/detached from different
 *                 devices
 */

static void omap_atomic_wait_for_completion(struct drm_device *dev,
                                            struct drm_atomic_state *old_state)
{
        struct drm_crtc_state *new_crtc_state;
        struct drm_crtc *crtc;
        unsigned int i;
        int ret;

        for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
                if (!new_crtc_state->active)
                        continue;

                ret = omap_crtc_wait_pending(crtc);

                if (!ret)
                        dev_warn(dev->dev,
                                 "atomic complete timeout (pipe %u)!\n", i);
        }
}

static void omap_atomic_commit_tail(struct drm_atomic_state *old_state)
{
        struct drm_device *dev = old_state->dev;
        struct omap_drm_private *priv = dev->dev_private;

        priv->dispc_ops->runtime_get(priv->dispc);

        /* Apply the atomic update. */
        drm_atomic_helper_commit_modeset_disables(dev, old_state);

        if (priv->omaprev != 0x3430) {
                /* With the current dss dispc implementation we have to enable
                 * the new modeset before we can commit planes. The dispc ovl
                 * configuration relies on the video mode configuration been
                 * written into the HW when the ovl configuration is
                 * calculated.
                 *
                 * This approach is not ideal because after a mode change the
                 * plane update is executed only after the first vblank
                 * interrupt. The dispc implementation should be fixed so that
                 * it is able use uncommitted drm state information.
                 */
                drm_atomic_helper_commit_modeset_enables(dev, old_state);
                omap_atomic_wait_for_completion(dev, old_state);

                drm_atomic_helper_commit_planes(dev, old_state, 0);

                drm_atomic_helper_commit_hw_done(old_state);
        } else {
                /*
                 * OMAP3 DSS seems to have issues with the work-around above,
                 * resulting in endless sync losts if a crtc is enabled without
                 * a plane. For now, skip the WA for OMAP3.
                 */
                drm_atomic_helper_commit_planes(dev, old_state, 0);

                drm_atomic_helper_commit_modeset_enables(dev, old_state);

                drm_atomic_helper_commit_hw_done(old_state);
        }

        /*
         * Wait for completion of the page flips to ensure that old buffers
         * can't be touched by the hardware anymore before cleaning up planes.
         */
        omap_atomic_wait_for_completion(dev, old_state);

        drm_atomic_helper_cleanup_planes(dev, old_state);

        priv->dispc_ops->runtime_put(priv->dispc);
}

static const struct drm_mode_config_helper_funcs omap_mode_config_helper_funcs = {
        .atomic_commit_tail = omap_atomic_commit_tail,
};

static const struct drm_mode_config_funcs omap_mode_config_funcs = {
        .fb_create = omap_framebuffer_create,
        .output_poll_changed = drm_fb_helper_output_poll_changed,
        .atomic_check = drm_atomic_helper_check,
        .atomic_commit = drm_atomic_helper_commit,
};

static void omap_disconnect_pipelines(struct drm_device *ddev)
{
        struct omap_drm_private *priv = ddev->dev_private;
        unsigned int i;

        for (i = 0; i < priv->num_pipes; i++) {
                struct omap_drm_pipeline *pipe = &priv->pipes[i];

                omapdss_device_disconnect(NULL, pipe->output);

                omapdss_device_put(pipe->output);
                omapdss_device_put(pipe->display);
                pipe->output = NULL;
                pipe->display = NULL;
        }

        memset(&priv->channels, 0, sizeof(priv->channels));

        priv->num_pipes = 0;
}

static int omap_compare_pipes(const void *a, const void *b)
{
        const struct omap_drm_pipeline *pipe1 = a;
        const struct omap_drm_pipeline *pipe2 = b;

        if (pipe1->display->alias_id > pipe2->display->alias_id)
                return 1;
        else if (pipe1->display->alias_id < pipe2->display->alias_id)
                return -1;
        return 0;
}

static int omap_connect_pipelines(struct drm_device *ddev)
{
        struct omap_drm_private *priv = ddev->dev_private;
        struct omap_dss_device *output = NULL;
        unsigned int i;
        int r;

        if (!omapdss_stack_is_ready())
                return -EPROBE_DEFER;

        for_each_dss_output(output) {
                r = omapdss_device_connect(priv->dss, NULL, output);
                if (r == -EPROBE_DEFER) {
                        omapdss_device_put(output);
                        goto cleanup;
                } else if (r) {
                        dev_warn(output->dev, "could not connect output %s\n",
                                 output->name);
                } else {
                        struct omap_drm_pipeline *pipe;

                        pipe = &priv->pipes[priv->num_pipes++];
                        pipe->output = omapdss_device_get(output);
                        pipe->display = omapdss_display_get(output);

                        if (priv->num_pipes == ARRAY_SIZE(priv->pipes)) {
                                /* To balance the 'for_each_dss_output' loop */
                                omapdss_device_put(output);
                                break;
                        }
                }
        }

        /* Sort the list by DT aliases */
        sort(priv->pipes, priv->num_pipes, sizeof(priv->pipes[0]),
             omap_compare_pipes, NULL);

        /*
         * Populate the pipeline lookup table by DISPC channel. Only one display
         * is allowed per channel.
         */
        for (i = 0; i < priv->num_pipes; ++i) {
                struct omap_drm_pipeline *pipe = &priv->pipes[i];
                enum omap_channel channel = pipe->output->dispc_channel;

                if (WARN_ON(priv->channels[channel] != NULL)) {
                        r = -EINVAL;
                        goto cleanup;
                }

                priv->channels[channel] = pipe;
        }

        return 0;

cleanup:
        /*
         * if we are deferring probe, we disconnect the devices we previously
         * connected
         */
        omap_disconnect_pipelines(ddev);

        return r;
}

static int omap_modeset_init_properties(struct drm_device *dev)
{
        struct omap_drm_private *priv = dev->dev_private;
        unsigned int num_planes = priv->dispc_ops->get_num_ovls(priv->dispc);

        priv->zorder_prop = drm_property_create_range(dev, 0, "zorder", 0,
                                                      num_planes - 1);
        if (!priv->zorder_prop)
                return -ENOMEM;

        return 0;
}

static int omap_modeset_init(struct drm_device *dev)
{
        struct omap_drm_private *priv = dev->dev_private;
        int num_ovls = priv->dispc_ops->get_num_ovls(priv->dispc);
        int num_mgrs = priv->dispc_ops->get_num_mgrs(priv->dispc);
        unsigned int i;
        int ret;
        u32 plane_crtc_mask;

        drm_mode_config_init(dev);

        ret = omap_modeset_init_properties(dev);
        if (ret < 0)
                return ret;

        /*
         * This function creates exactly one connector, encoder, crtc,
         * and primary plane per each connected dss-device. Each
         * connector->encoder->crtc chain is expected to be separate
         * and each crtc is connect to a single dss-channel. If the
         * configuration does not match the expectations or exceeds
         * the available resources, the configuration is rejected.
         */
        if (priv->num_pipes > num_mgrs || priv->num_pipes > num_ovls) {
                dev_err(dev->dev, "%s(): Too many connected displays\n",
                        __func__);
                return -EINVAL;
        }

        /* Create all planes first. They can all be put to any CRTC. */
        plane_crtc_mask = (1 << priv->num_pipes) - 1;

        for (i = 0; i < num_ovls; i++) {
                enum drm_plane_type type = i < priv->num_pipes
                                         ? DRM_PLANE_TYPE_PRIMARY
                                         : DRM_PLANE_TYPE_OVERLAY;
                struct drm_plane *plane;

                if (WARN_ON(priv->num_planes >= ARRAY_SIZE(priv->planes)))
                        return -EINVAL;

                plane = omap_plane_init(dev, i, type, plane_crtc_mask);
                if (IS_ERR(plane))
                        return PTR_ERR(plane);

                priv->planes[priv->num_planes++] = plane;
        }

        /* Create the CRTCs, encoders and connectors. */
        for (i = 0; i < priv->num_pipes; i++) {
                struct omap_drm_pipeline *pipe = &priv->pipes[i];
                struct omap_dss_device *display = pipe->display;
                struct drm_connector *connector;
                struct drm_encoder *encoder;
                struct drm_crtc *crtc;

                encoder = omap_encoder_init(dev, pipe->output, display);
                if (!encoder)
                        return -ENOMEM;

                connector = omap_connector_init(dev, pipe->output, display,
                                                encoder);
                if (!connector)
                        return -ENOMEM;

                crtc = omap_crtc_init(dev, pipe, priv->planes[i]);
                if (IS_ERR(crtc))
                        return PTR_ERR(crtc);

                drm_connector_attach_encoder(connector, encoder);
                encoder->possible_crtcs = 1 << i;

                pipe->crtc = crtc;
                pipe->encoder = encoder;
                pipe->connector = connector;
        }

        DBG("registered %u planes, %u crtcs/encoders/connectors\n",
            priv->num_planes, priv->num_pipes);

        dev->mode_config.min_width = 8;
        dev->mode_config.min_height = 2;

        /*
         * Note: these values are used for multiple independent things:
         * connector mode filtering, buffer sizes, crtc sizes...
         * Use big enough values here to cover all use cases, and do more
         * specific checking in the respective code paths.
         */
        dev->mode_config.max_width = 8192;
        dev->mode_config.max_height = 8192;

        /* We want the zpos to be normalized */
        dev->mode_config.normalize_zpos = true;

        dev->mode_config.funcs = &omap_mode_config_funcs;
        dev->mode_config.helper_private = &omap_mode_config_helper_funcs;

        drm_mode_config_reset(dev);

        omap_drm_irq_install(dev);

        return 0;
}

/*
 * Enable the HPD in external components if supported
 */
static void omap_modeset_enable_external_hpd(struct drm_device *ddev)
{
        struct omap_drm_private *priv = ddev->dev_private;
        int i;

        for (i = 0; i < priv->num_pipes; i++)
                omap_connector_enable_hpd(priv->pipes[i].connector);
}

/*
 * Disable the HPD in external components if supported
 */
static void omap_modeset_disable_external_hpd(struct drm_device *ddev)
{
        struct omap_drm_private *priv = ddev->dev_private;
        int i;

        for (i = 0; i < priv->num_pipes; i++)
                omap_connector_disable_hpd(priv->pipes[i].connector);
}

/*
 * drm ioctl funcs
 */


static int ioctl_get_param(struct drm_device *dev, void *data,
                struct drm_file *file_priv)
{
        struct omap_drm_private *priv = dev->dev_private;
        struct drm_omap_param *args = data;

        DBG("%p: param=%llu", dev, args->param);

        switch (args->param) {
        case OMAP_PARAM_CHIPSET_ID:
                args->value = priv->omaprev;
                break;
        default:
                DBG("unknown parameter %lld", args->param);
                return -EINVAL;
        }

        return 0;
}

static int ioctl_set_param(struct drm_device *dev, void *data,
                struct drm_file *file_priv)
{
        struct drm_omap_param *args = data;

        switch (args->param) {
        default:
                DBG("unknown parameter %lld", args->param);
                return -EINVAL;
        }

        return 0;
}

#define OMAP_BO_USER_MASK       0x00ffffff      /* flags settable by userspace */

static int ioctl_gem_new(struct drm_device *dev, void *data,
                struct drm_file *file_priv)
{
        struct drm_omap_gem_new *args = data;
        u32 flags = args->flags & OMAP_BO_USER_MASK;

        VERB("%p:%p: size=0x%08x, flags=%08x", dev, file_priv,
             args->size.bytes, flags);

        return omap_gem_new_handle(dev, file_priv, args->size, flags,
                                   &args->handle);
}

static int ioctl_gem_info(struct drm_device *dev, void *data,
                struct drm_file *file_priv)
{
        struct drm_omap_gem_info *args = data;
        struct drm_gem_object *obj;
        int ret = 0;

        VERB("%p:%p: handle=%d", dev, file_priv, args->handle);

        obj = drm_gem_object_lookup(file_priv, args->handle);
        if (!obj)
                return -ENOENT;

        args->size = omap_gem_mmap_size(obj);
        args->offset = omap_gem_mmap_offset(obj);

        drm_gem_object_put_unlocked(obj);

        return ret;
}

static const struct drm_ioctl_desc ioctls[DRM_COMMAND_END - DRM_COMMAND_BASE] = {
        DRM_IOCTL_DEF_DRV(OMAP_GET_PARAM, ioctl_get_param,
                          DRM_AUTH | DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(OMAP_SET_PARAM, ioctl_set_param,
                          DRM_AUTH | DRM_MASTER | DRM_ROOT_ONLY),
        DRM_IOCTL_DEF_DRV(OMAP_GEM_NEW, ioctl_gem_new,
                          DRM_AUTH | DRM_RENDER_ALLOW),
        /* Deprecated, to be removed. */
        DRM_IOCTL_DEF_DRV(OMAP_GEM_CPU_PREP, drm_noop,
                          DRM_AUTH | DRM_RENDER_ALLOW),
        /* Deprecated, to be removed. */
        DRM_IOCTL_DEF_DRV(OMAP_GEM_CPU_FINI, drm_noop,
                          DRM_AUTH | DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(OMAP_GEM_INFO, ioctl_gem_info,
                          DRM_AUTH | DRM_RENDER_ALLOW),
};

/*
 * drm driver funcs
 */

static int dev_open(struct drm_device *dev, struct drm_file *file)
{
        file->driver_priv = NULL;

        DBG("open: dev=%p, file=%p", dev, file);

        return 0;
}

static const struct vm_operations_struct omap_gem_vm_ops = {
        .fault = omap_gem_fault,
        .open = drm_gem_vm_open,
        .close = drm_gem_vm_close,
};

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

static struct drm_driver omap_drm_driver = {
        .driver_features = DRIVER_MODESET | DRIVER_GEM  | DRIVER_PRIME |
                DRIVER_ATOMIC | DRIVER_RENDER,
        .open = dev_open,
        .lastclose = drm_fb_helper_lastclose,
#ifdef CONFIG_DEBUG_FS
        .debugfs_init = omap_debugfs_init,
#endif
        .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
        .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
        .gem_prime_export = omap_gem_prime_export,
        .gem_prime_import = omap_gem_prime_import,
        .gem_free_object_unlocked = omap_gem_free_object,
        .gem_vm_ops = &omap_gem_vm_ops,
        .dumb_create = omap_gem_dumb_create,
        .dumb_map_offset = omap_gem_dumb_map_offset,
        .ioctls = ioctls,
        .num_ioctls = DRM_OMAP_NUM_IOCTLS,
        .fops = &omapdriver_fops,
        .name = DRIVER_NAME,
        .desc = DRIVER_DESC,
        .date = DRIVER_DATE,
        .major = DRIVER_MAJOR,
        .minor = DRIVER_MINOR,
        .patchlevel = DRIVER_PATCHLEVEL,
};

static const struct soc_device_attribute omapdrm_soc_devices[] = {
        { .family = "OMAP3", .data = (void *)0x3430 },
        { .family = "OMAP4", .data = (void *)0x4430 },
        { .family = "OMAP5", .data = (void *)0x5430 },
        { .family = "DRA7",  .data = (void *)0x0752 },
        { /* sentinel */ }
};

static int omapdrm_init(struct omap_drm_private *priv, struct device *dev)
{
        const struct soc_device_attribute *soc;
        struct drm_device *ddev;
        unsigned int i;
        int ret;

        DBG("%s", dev_name(dev));

        /* Allocate and initialize the DRM device. */
        ddev = drm_dev_alloc(&omap_drm_driver, dev);
        if (IS_ERR(ddev))
                return PTR_ERR(ddev);

        priv->ddev = ddev;
        ddev->dev_private = priv;

        priv->dev = dev;
        priv->dss = omapdss_get_dss();
        priv->dispc = dispc_get_dispc(priv->dss);
        priv->dispc_ops = dispc_get_ops(priv->dss);

        omap_crtc_pre_init(priv);

        ret = omap_connect_pipelines(ddev);
        if (ret)
                goto err_crtc_uninit;

        soc = soc_device_match(omapdrm_soc_devices);
        priv->omaprev = soc ? (unsigned int)soc->data : 0;
        priv->wq = alloc_ordered_workqueue("omapdrm", 0);

        mutex_init(&priv->list_lock);
        INIT_LIST_HEAD(&priv->obj_list);

        /* Get memory bandwidth limits */
        if (priv->dispc_ops->get_memory_bandwidth_limit)
                priv->max_bandwidth =
                        priv->dispc_ops->get_memory_bandwidth_limit(priv->dispc);

        omap_gem_init(ddev);

        ret = omap_modeset_init(ddev);
        if (ret) {
                dev_err(priv->dev, "omap_modeset_init failed: ret=%d\n", ret);
                goto err_gem_deinit;
        }

        /* Initialize vblank handling, start with all CRTCs disabled. */
        ret = drm_vblank_init(ddev, priv->num_pipes);
        if (ret) {
                dev_err(priv->dev, "could not init vblank\n");
                goto err_cleanup_modeset;
        }

        for (i = 0; i < priv->num_pipes; i++)
                drm_crtc_vblank_off(priv->pipes[i].crtc);

        omap_fbdev_init(ddev);

        drm_kms_helper_poll_init(ddev);
        omap_modeset_enable_external_hpd(ddev);

        /*
         * Register the DRM device with the core and the connectors with
         * sysfs.
         */
        ret = drm_dev_register(ddev, 0);
        if (ret)
                goto err_cleanup_helpers;

        return 0;

err_cleanup_helpers:
        omap_modeset_disable_external_hpd(ddev);
        drm_kms_helper_poll_fini(ddev);

        omap_fbdev_fini(ddev);
err_cleanup_modeset:
        drm_mode_config_cleanup(ddev);
        omap_drm_irq_uninstall(ddev);
err_gem_deinit:
        omap_gem_deinit(ddev);
        destroy_workqueue(priv->wq);
        omap_disconnect_pipelines(ddev);
err_crtc_uninit:
        omap_crtc_pre_uninit(priv);
        drm_dev_put(ddev);
        return ret;
}

static void omapdrm_cleanup(struct omap_drm_private *priv)
{
        struct drm_device *ddev = priv->ddev;

        DBG("");

        drm_dev_unregister(ddev);

        omap_modeset_disable_external_hpd(ddev);
        drm_kms_helper_poll_fini(ddev);

        omap_fbdev_fini(ddev);

        drm_atomic_helper_shutdown(ddev);

        drm_mode_config_cleanup(ddev);

        omap_drm_irq_uninstall(ddev);
        omap_gem_deinit(ddev);

        destroy_workqueue(priv->wq);

        omap_disconnect_pipelines(ddev);
        omap_crtc_pre_uninit(priv);

        drm_dev_put(ddev);
}

static int pdev_probe(struct platform_device *pdev)
{
        struct omap_drm_private *priv;
        int ret;

        if (omapdss_is_initialized() == false)
                return -EPROBE_DEFER;

        ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
        if (ret) {
                dev_err(&pdev->dev, "Failed to set the DMA mask\n");
                return ret;
        }

        /* Allocate and initialize the driver private structure. */
        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        platform_set_drvdata(pdev, priv);

        ret = omapdrm_init(priv, &pdev->dev);
        if (ret < 0)
                kfree(priv);

        return ret;
}

static int pdev_remove(struct platform_device *pdev)
{
        struct omap_drm_private *priv = platform_get_drvdata(pdev);

        omapdrm_cleanup(priv);
        kfree(priv);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int omap_drm_suspend_all_displays(struct drm_device *ddev)
{
        struct omap_drm_private *priv = ddev->dev_private;
        int i;

        for (i = 0; i < priv->num_pipes; i++) {
                struct omap_dss_device *display = priv->pipes[i].display;

                if (display->state == OMAP_DSS_DISPLAY_ACTIVE) {
                        display->ops->disable(display);
                        display->activate_after_resume = true;
                } else {
                        display->activate_after_resume = false;
                }
        }

        return 0;
}

static int omap_drm_resume_all_displays(struct drm_device *ddev)
{
        struct omap_drm_private *priv = ddev->dev_private;
        int i;

        for (i = 0; i < priv->num_pipes; i++) {
                struct omap_dss_device *display = priv->pipes[i].display;

                if (display->activate_after_resume) {
                        display->ops->enable(display);
                        display->activate_after_resume = false;
                }
        }

        return 0;
}

static int omap_drm_suspend(struct device *dev)
{
        struct omap_drm_private *priv = dev_get_drvdata(dev);
        struct drm_device *drm_dev = priv->ddev;

        drm_kms_helper_poll_disable(drm_dev);

        drm_modeset_lock_all(drm_dev);
        omap_drm_suspend_all_displays(drm_dev);
        drm_modeset_unlock_all(drm_dev);

        return 0;
}

static int omap_drm_resume(struct device *dev)
{
        struct omap_drm_private *priv = dev_get_drvdata(dev);
        struct drm_device *drm_dev = priv->ddev;

        drm_modeset_lock_all(drm_dev);
        omap_drm_resume_all_displays(drm_dev);
        drm_modeset_unlock_all(drm_dev);

        drm_kms_helper_poll_enable(drm_dev);

        return omap_gem_resume(drm_dev);
}
#endif

static SIMPLE_DEV_PM_OPS(omapdrm_pm_ops, omap_drm_suspend, omap_drm_resume);

static struct platform_driver pdev = {
        .driver = {
                .name = "omapdrm",
                .pm = &omapdrm_pm_ops,
        },
        .probe = pdev_probe,
        .remove = pdev_remove,
};

static struct platform_driver * const drivers[] = {
        &omap_dmm_driver,
        &pdev,
};

static int __init omap_drm_init(void)
{
        DBG("init");

        return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
}

static void __exit omap_drm_fini(void)
{
        DBG("fini");

        platform_unregister_drivers(drivers, ARRAY_SIZE(drivers));
}

/* need late_initcall() so we load after dss_driver's are loaded */
late_initcall(omap_drm_init);
module_exit(omap_drm_fini);

MODULE_AUTHOR("Rob Clark <rob@ti.com>");
MODULE_DESCRIPTION("OMAP DRM Display Driver");
MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_LICENSE("GPL v2");