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