drm.c

/*
 * Copyright (C) 2012 Avionic Design GmbH
 * Copyright (C) 2012-2013 NVIDIA CORPORATION.  All rights reserved.
 *
 * 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.
 */

#include <linux/host1x.h>
#include <linux/iommu.h>

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

#include "drm.h"
#include "gem.h"

#define DRIVER_NAME "tegra"
#define DRIVER_DESC "NVIDIA Tegra graphics"
#define DRIVER_DATE "20120330"
#define DRIVER_MAJOR 0
#define DRIVER_MINOR 0
#define DRIVER_PATCHLEVEL 0

struct tegra_drm_file {
	struct list_head contexts;
};

static void tegra_atomic_schedule(struct tegra_drm *tegra,
				  struct drm_atomic_state *state)
{
	tegra->commit.state = state;
	schedule_work(&tegra->commit.work);
}

static void tegra_atomic_complete(struct tegra_drm *tegra,
				  struct drm_atomic_state *state)
{
	struct drm_device *drm = tegra->drm;

	/*
	 * Everything below can be run asynchronously without the need to grab
	 * any modeset locks at all under one condition: It must be guaranteed
	 * that the asynchronous work has either been cancelled (if the driver
	 * supports it, which at least requires that the framebuffers get
	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
	 * before the new state gets committed on the software side with
	 * drm_atomic_helper_swap_state().
	 *
	 * This scheme allows new atomic state updates to be prepared and
	 * checked in parallel to the asynchronous completion of the previous
	 * update. Which is important since compositors need to figure out the
	 * composition of the next frame right after having submitted the
	 * current layout.
	 */

	drm_atomic_helper_commit_pre_planes(drm, state);
	drm_atomic_helper_commit_planes(drm, state);
	drm_atomic_helper_commit_post_planes(drm, state);

	drm_atomic_helper_wait_for_vblanks(drm, state);

	drm_atomic_helper_cleanup_planes(drm, state);
	drm_atomic_state_free(state);
}

static void tegra_atomic_work(struct work_struct *work)
{
	struct tegra_drm *tegra = container_of(work, struct tegra_drm,
					       commit.work);

	tegra_atomic_complete(tegra, tegra->commit.state);
}

static int tegra_atomic_commit(struct drm_device *drm,
			       struct drm_atomic_state *state, bool async)
{
	struct tegra_drm *tegra = drm->dev_private;
	int err;

	err = drm_atomic_helper_prepare_planes(drm, state);
	if (err)
		return err;

	/* serialize outstanding asynchronous commits */
	mutex_lock(&tegra->commit.lock);
	flush_work(&tegra->commit.work);

	/*
	 * This is the point of no return - everything below never fails except
	 * when the hw goes bonghits. Which means we can commit the new state on
	 * the software side now.
	 */

	drm_atomic_helper_swap_state(drm, state);

	if (async)
		tegra_atomic_schedule(tegra, state);
	else
		tegra_atomic_complete(tegra, state);

	mutex_unlock(&tegra->commit.lock);
	return 0;
}

static const struct drm_mode_config_funcs tegra_drm_mode_funcs = {
	.fb_create = tegra_fb_create,
#ifdef CONFIG_DRM_TEGRA_FBDEV
	.output_poll_changed = tegra_fb_output_poll_changed,
#endif
	.atomic_check = drm_atomic_helper_check,
	.atomic_commit = tegra_atomic_commit,
};

static int tegra_drm_load(struct drm_device *drm, unsigned long flags)
{
	struct host1x_device *device = to_host1x_device(drm->dev);
	struct tegra_drm *tegra;
	int err;

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

	if (iommu_present(&platform_bus_type)) {
		tegra->domain = iommu_domain_alloc(&platform_bus_type);
		if (!tegra->domain) {
			err = -ENOMEM;
			goto free;
		}

		DRM_DEBUG("IOMMU context initialized\n");
		drm_mm_init(&tegra->mm, 0, SZ_2G);
	}

	mutex_init(&tegra->clients_lock);
	INIT_LIST_HEAD(&tegra->clients);

	mutex_init(&tegra->commit.lock);
	INIT_WORK(&tegra->commit.work, tegra_atomic_work);

	drm->dev_private = tegra;
	tegra->drm = drm;

	drm_mode_config_init(drm);

	drm->mode_config.min_width = 0;
	drm->mode_config.min_height = 0;

	drm->mode_config.max_width = 4096;
	drm->mode_config.max_height = 4096;

	drm->mode_config.funcs = &tegra_drm_mode_funcs;

	err = tegra_drm_fb_prepare(drm);
	if (err < 0)
		goto config;

	drm_kms_helper_poll_init(drm);

	err = host1x_device_init(device);
	if (err < 0)
		goto fbdev;

	drm_mode_config_reset(drm);

	/*
	 * We don't use the drm_irq_install() helpers provided by the DRM
	 * core, so we need to set this manually in order to allow the
	 * DRM_IOCTL_WAIT_VBLANK to operate correctly.
	 */
	drm->irq_enabled = true;

	err = drm_vblank_init(drm, drm->mode_config.num_crtc);
	if (err < 0)
		goto device;

	err = tegra_drm_fb_init(drm);
	if (err < 0)
		goto vblank;

	return 0;

vblank:
	drm_vblank_cleanup(drm);
device:
	host1x_device_exit(device);
fbdev:
	drm_kms_helper_poll_fini(drm);
	tegra_drm_fb_free(drm);
config:
	drm_mode_config_cleanup(drm);

	if (tegra->domain) {
		iommu_domain_free(tegra->domain);
		drm_mm_takedown(&tegra->mm);
	}
free:
	kfree(tegra);