1/*
  2 * Copyright (C) 2015 Broadcom
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License version 2 as
  6 * published by the Free Software Foundation.
  7 */
  8
  9/**
 10 * DOC: VC4 KMS
 11 *
 12 * This is the general code for implementing KMS mode setting that
 13 * doesn't clearly associate with any of the other objects (plane,
 14 * crtc, HDMI encoder).
 15 */
 16
 17#include <drm/drm_crtc.h>
 18#include <drm/drm_atomic.h>
 19#include <drm/drm_atomic_helper.h>
 20#include <drm/drm_crtc_helper.h>
 21#include <drm/drm_plane_helper.h>
 22#include <drm/drm_fb_helper.h>
 23#include <drm/drm_fb_cma_helper.h>
 24#include <drm/drm_gem_framebuffer_helper.h>
 25#include "vc4_drv.h"
 26
 27static void
 28vc4_atomic_complete_commit(struct drm_atomic_state *state)
 29{
 30	struct drm_device *dev = state->dev;
 31	struct vc4_dev *vc4 = to_vc4_dev(dev);
 32
 33	drm_atomic_helper_wait_for_fences(dev, state, false);
 34
 35	drm_atomic_helper_wait_for_dependencies(state);
 36
 37	drm_atomic_helper_commit_modeset_disables(dev, state);
 38
 39	drm_atomic_helper_commit_planes(dev, state, 0);
 40
 41	drm_atomic_helper_commit_modeset_enables(dev, state);
 42
 43	/* Make sure that drm_atomic_helper_wait_for_vblanks()
 44	 * actually waits for vblank.  If we're doing a full atomic
 45	 * modeset (as opposed to a vc4_update_plane() short circuit),
 46	 * then we need to wait for scanout to be done with our
 47	 * display lists before we free it and potentially reallocate
 48	 * and overwrite the dlist memory with a new modeset.
 49	 */
 50	state->legacy_cursor_update = false;
 51
 52	drm_atomic_helper_commit_hw_done(state);
 53
 54	drm_atomic_helper_wait_for_vblanks(dev, state);
 55
 56	drm_atomic_helper_cleanup_planes(dev, state);
 57
 58	drm_atomic_helper_commit_cleanup_done(state);
 59
 60	drm_atomic_state_put(state);
 61
 62	up(&vc4->async_modeset);
 63}
 64
 65static void commit_work(struct work_struct *work)
 66{
 67	struct drm_atomic_state *state = container_of(work,
 68						      struct drm_atomic_state,
 69						      commit_work);
 70	vc4_atomic_complete_commit(state);
 71}
 72
 73/**
 74 * vc4_atomic_commit - commit validated state object
 75 * @dev: DRM device
 76 * @state: the driver state object
 77 * @nonblock: nonblocking commit
 78 *
 79 * This function commits a with drm_atomic_helper_check() pre-validated state
 80 * object. This can still fail when e.g. the framebuffer reservation fails. For
 81 * now this doesn't implement asynchronous commits.
 82 *
 83 * RETURNS
 84 * Zero for success or -errno.
 85 */
 86static int vc4_atomic_commit(struct drm_device *dev,
 87			     struct drm_atomic_state *state,
 88			     bool nonblock)
 89{
 90	struct vc4_dev *vc4 = to_vc4_dev(dev);
 91	int ret;
 92
 93	ret = drm_atomic_helper_setup_commit(state, nonblock);
 94	if (ret)
 95		return ret;
 96
 97	INIT_WORK(&state->commit_work, commit_work);
 98
 99	ret = down_interruptible(&vc4->async_modeset);
100	if (ret)
101		return ret;
102
103	ret = drm_atomic_helper_prepare_planes(dev, state);
104	if (ret) {
105		up(&vc4->async_modeset);
106		return ret;
107	}
108
109	if (!nonblock) {
110		ret = drm_atomic_helper_wait_for_fences(dev, state, true);
111		if (ret) {
112			drm_atomic_helper_cleanup_planes(dev, state);
113			up(&vc4->async_modeset);
114			return ret;
115		}
116	}
117
118	/*
119	 * This is the point of no return - everything below never fails except
120	 * when the hw goes bonghits. Which means we can commit the new state on
121	 * the software side now.
122	 */
123
124	BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);
125
126	/*
127	 * Everything below can be run asynchronously without the need to grab
128	 * any modeset locks at all under one condition: It must be guaranteed
129	 * that the asynchronous work has either been cancelled (if the driver
130	 * supports it, which at least requires that the framebuffers get
131	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
132	 * before the new state gets committed on the software side with
133	 * drm_atomic_helper_swap_state().
134	 *
135	 * This scheme allows new atomic state updates to be prepared and
136	 * checked in parallel to the asynchronous completion of the previous
137	 * update. Which is important since compositors need to figure out the
138	 * composition of the next frame right after having submitted the
139	 * current layout.
140	 */
141
142	drm_atomic_state_get(state);
143	if (nonblock)
144		queue_work(system_unbound_wq, &state->commit_work);
145	else
146		vc4_atomic_complete_commit(state);
147
148	return 0;
149}
150
151static struct drm_framebuffer *vc4_fb_create(struct drm_device *dev,
152					     struct drm_file *file_priv,
153					     const struct drm_mode_fb_cmd2 *mode_cmd)
154{
155	struct drm_mode_fb_cmd2 mode_cmd_local;
156
157	/* If the user didn't specify a modifier, use the
158	 * vc4_set_tiling_ioctl() state for the BO.
159	 */
160	if (!(mode_cmd->flags & DRM_MODE_FB_MODIFIERS)) {
161		struct drm_gem_object *gem_obj;
162		struct vc4_bo *bo;
163
164		gem_obj = drm_gem_object_lookup(file_priv,
165						mode_cmd->handles[0]);
166		if (!gem_obj) {
167			DRM_DEBUG("Failed to look up GEM BO %d\n",
168				  mode_cmd->handles[0]);
169			return ERR_PTR(-ENOENT);
170		}
171		bo = to_vc4_bo(gem_obj);
172
173		mode_cmd_local = *mode_cmd;
174
175		if (bo->t_format) {
176			mode_cmd_local.modifier[0] =
177				DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
178		} else {
179			mode_cmd_local.modifier[0] = DRM_FORMAT_MOD_NONE;
180		}
181
182		drm_gem_object_put_unlocked(gem_obj);
183
184		mode_cmd = &mode_cmd_local;
185	}
186
187	return drm_gem_fb_create(dev, file_priv, mode_cmd);
188}
189
190static const struct drm_mode_config_funcs vc4_mode_funcs = {
191	.output_poll_changed = drm_fb_helper_output_poll_changed,
192	.atomic_check = drm_atomic_helper_check,
193	.atomic_commit = vc4_atomic_commit,
194	.fb_create = vc4_fb_create,
195};
196
197int vc4_kms_load(struct drm_device *dev)
198{
199	struct vc4_dev *vc4 = to_vc4_dev(dev);
200	int ret;
201
202	sema_init(&vc4->async_modeset, 1);
203
204	/* Set support for vblank irq fast disable, before drm_vblank_init() */
205	dev->vblank_disable_immediate = true;
206
207	ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
208	if (ret < 0) {
209		dev_err(dev->dev, "failed to initialize vblank\n");
210		return ret;
211	}
212
213	dev->mode_config.max_width = 2048;
214	dev->mode_config.max_height = 2048;
215	dev->mode_config.funcs = &vc4_mode_funcs;
216	dev->mode_config.preferred_depth = 24;
217	dev->mode_config.async_page_flip = true;
218	dev->mode_config.allow_fb_modifiers = true;
219
220	drm_mode_config_reset(dev);
221
222	if (dev->mode_config.num_connector)
223		drm_fb_cma_fbdev_init(dev, 32, 0);
224
225	drm_kms_helper_poll_init(dev);
226
227	return 0;
228}