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_crtc.h" 18 #include "drm_atomic.h" 19 #include "drm_atomic_helper.h" 20 #include "drm_crtc_helper.h" 21 #include "drm_plane_helper.h" 22 #include "drm_fb_cma_helper.h" 23 #include "vc4_drv.h" 24 25 static void vc4_output_poll_changed(struct drm_device *dev) 26 { 27 struct vc4_dev *vc4 = to_vc4_dev(dev); 28 29 if (vc4->fbdev) 30 drm_fbdev_cma_hotplug_event(vc4->fbdev); 31 } 32 33 struct vc4_commit { 34 struct drm_device *dev; 35 struct drm_atomic_state *state; 36 struct vc4_seqno_cb cb; 37 }; 38 39 static void 40 vc4_atomic_complete_commit(struct vc4_commit *c) 41 { 42 struct drm_atomic_state *state = c->state; 43 struct drm_device *dev = state->dev; 44 struct vc4_dev *vc4 = to_vc4_dev(dev); 45 46 drm_atomic_helper_commit_modeset_disables(dev, state); 47 48 drm_atomic_helper_commit_planes(dev, state, false); 49 50 drm_atomic_helper_commit_modeset_enables(dev, state); 51 52 /* Make sure that drm_atomic_helper_wait_for_vblanks() 53 * actually waits for vblank. If we're doing a full atomic 54 * modeset (as opposed to a vc4_update_plane() short circuit), 55 * then we need to wait for scanout to be done with our 56 * display lists before we free it and potentially reallocate 57 * and overwrite the dlist memory with a new modeset. 58 */ 59 state->legacy_cursor_update = false; 60 61 drm_atomic_helper_wait_for_vblanks(dev, state); 62 63 drm_atomic_helper_cleanup_planes(dev, state); 64 65 drm_atomic_state_free(state); 66 67 up(&vc4->async_modeset); 68 69 kfree(c); 70 } 71 72 static void 73 vc4_atomic_complete_commit_seqno_cb(struct vc4_seqno_cb *cb) 74 { 75 struct vc4_commit *c = container_of(cb, struct vc4_commit, cb); 76 77 vc4_atomic_complete_commit(c); 78 } 79 80 static struct vc4_commit *commit_init(struct drm_atomic_state *state) 81 { 82 struct vc4_commit *c = kzalloc(sizeof(*c), GFP_KERNEL); 83 84 if (!c) 85 return NULL; 86 c->dev = state->dev; 87 c->state = state; 88 89 return c; 90 } 91 92 /** 93 * vc4_atomic_commit - commit validated state object 94 * @dev: DRM device 95 * @state: the driver state object 96 * @nonblock: nonblocking commit 97 * 98 * This function commits a with drm_atomic_helper_check() pre-validated state 99 * object. This can still fail when e.g. the framebuffer reservation fails. For 100 * now this doesn't implement asynchronous commits. 101 * 102 * RETURNS 103 * Zero for success or -errno. 104 */ 105 static int vc4_atomic_commit(struct drm_device *dev, 106 struct drm_atomic_state *state, 107 bool nonblock) 108 { 109 struct vc4_dev *vc4 = to_vc4_dev(dev); 110 int ret; 111 int i; 112 uint64_t wait_seqno = 0; 113 struct vc4_commit *c; 114 115 c = commit_init(state); 116 if (!c) 117 return -ENOMEM; 118 119 /* Make sure that any outstanding modesets have finished. */ 120 if (nonblock) { 121 ret = down_trylock(&vc4->async_modeset); 122 if (ret) { 123 kfree(c); 124 return -EBUSY; 125 } 126 } else { 127 ret = down_interruptible(&vc4->async_modeset); 128 if (ret) { 129 kfree(c); 130 return ret; 131 } 132 } 133 134 ret = drm_atomic_helper_prepare_planes(dev, state); 135 if (ret) { 136 kfree(c); 137 up(&vc4->async_modeset); 138 return ret; 139 } 140 141 for (i = 0; i < dev->mode_config.num_total_plane; i++) { 142 struct drm_plane *plane = state->planes[i]; 143 struct drm_plane_state *new_state = state->plane_states[i]; 144 145 if (!plane) 146 continue; 147 148 if ((plane->state->fb != new_state->fb) && new_state->fb) { 149 struct drm_gem_cma_object *cma_bo = 150 drm_fb_cma_get_gem_obj(new_state->fb, 0); 151 struct vc4_bo *bo = to_vc4_bo(&cma_bo->base); 152 153 wait_seqno = max(bo->seqno, wait_seqno); 154 } 155 } 156 157 /* 158 * This is the point of no return - everything below never fails except 159 * when the hw goes bonghits. Which means we can commit the new state on 160 * the software side now. 161 */ 162 163 drm_atomic_helper_swap_state(dev, state); 164 165 /* 166 * Everything below can be run asynchronously without the need to grab 167 * any modeset locks at all under one condition: It must be guaranteed 168 * that the asynchronous work has either been cancelled (if the driver 169 * supports it, which at least requires that the framebuffers get 170 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed 171 * before the new state gets committed on the software side with 172 * drm_atomic_helper_swap_state(). 173 * 174 * This scheme allows new atomic state updates to be prepared and 175 * checked in parallel to the asynchronous completion of the previous 176 * update. Which is important since compositors need to figure out the 177 * composition of the next frame right after having submitted the 178 * current layout. 179 */ 180 181 if (nonblock) { 182 vc4_queue_seqno_cb(dev, &c->cb, wait_seqno, 183 vc4_atomic_complete_commit_seqno_cb); 184 } else { 185 vc4_wait_for_seqno(dev, wait_seqno, ~0ull, false); 186 vc4_atomic_complete_commit(c); 187 } 188 189 return 0; 190 } 191 192 static const struct drm_mode_config_funcs vc4_mode_funcs = { 193 .output_poll_changed = vc4_output_poll_changed, 194 .atomic_check = drm_atomic_helper_check, 195 .atomic_commit = vc4_atomic_commit, 196 .fb_create = drm_fb_cma_create, 197 }; 198 199 int vc4_kms_load(struct drm_device *dev) 200 { 201 struct vc4_dev *vc4 = to_vc4_dev(dev); 202 int ret; 203 204 sema_init(&vc4->async_modeset, 1); 205 206 ret = drm_vblank_init(dev, dev->mode_config.num_crtc); 207 if (ret < 0) { 208 dev_err(dev->dev, "failed to initialize vblank\n"); 209 return ret; 210 } 211 212 dev->mode_config.max_width = 2048; 213 dev->mode_config.max_height = 2048; 214 dev->mode_config.funcs = &vc4_mode_funcs; 215 dev->mode_config.preferred_depth = 24; 216 dev->mode_config.async_page_flip = true; 217 218 drm_mode_config_reset(dev); 219 220 vc4->fbdev = drm_fbdev_cma_init(dev, 32, 221 dev->mode_config.num_crtc, 222 dev->mode_config.num_connector); 223 if (IS_ERR(vc4->fbdev)) 224 vc4->fbdev = NULL; 225 226 drm_kms_helper_poll_init(dev); 227 228 return 0; 229 } 230