1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2016 Noralf Trønnes 4 */ 5 6 #include <linux/module.h> 7 #include <linux/slab.h> 8 9 #include <drm/drm_atomic.h> 10 #include <drm/drm_atomic_helper.h> 11 #include <drm/drm_bridge.h> 12 #include <drm/drm_plane_helper.h> 13 #include <drm/drm_probe_helper.h> 14 #include <drm/drm_simple_kms_helper.h> 15 16 /** 17 * DOC: overview 18 * 19 * This helper library provides helpers for drivers for simple display 20 * hardware. 21 * 22 * drm_simple_display_pipe_init() initializes a simple display pipeline 23 * which has only one full-screen scanout buffer feeding one output. The 24 * pipeline is represented by &struct drm_simple_display_pipe and binds 25 * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed 26 * entity. Some flexibility for code reuse is provided through a separately 27 * allocated &drm_connector object and supporting optional &drm_bridge 28 * encoder drivers. 29 * 30 * Many drivers require only a very simple encoder that fulfills the minimum 31 * requirements of the display pipeline and does not add additional 32 * functionality. The function drm_simple_encoder_init() provides an 33 * implementation of such an encoder. 34 */ 35 36 static const struct drm_encoder_funcs drm_simple_encoder_funcs_cleanup = { 37 .destroy = drm_encoder_cleanup, 38 }; 39 40 /** 41 * drm_simple_encoder_init - Initialize a preallocated encoder with 42 * basic functionality. 43 * @dev: drm device 44 * @encoder: the encoder to initialize 45 * @encoder_type: user visible type of the encoder 46 * 47 * Initialises a preallocated encoder that has no further functionality. 48 * Settings for possible CRTC and clones are left to their initial values. 49 * The encoder will be cleaned up automatically as part of the mode-setting 50 * cleanup. 51 * 52 * The caller of drm_simple_encoder_init() is responsible for freeing 53 * the encoder's memory after the encoder has been cleaned up. At the 54 * moment this only works reliably if the encoder data structure is 55 * stored in the device structure. Free the encoder's memory as part of 56 * the device release function. 57 * 58 * FIXME: Later improvements to DRM's resource management may allow for 59 * an automated kfree() of the encoder's memory. 60 * 61 * Returns: 62 * Zero on success, error code on failure. 63 */ 64 int drm_simple_encoder_init(struct drm_device *dev, 65 struct drm_encoder *encoder, 66 int encoder_type) 67 { 68 return drm_encoder_init(dev, encoder, 69 &drm_simple_encoder_funcs_cleanup, 70 encoder_type, NULL); 71 } 72 EXPORT_SYMBOL(drm_simple_encoder_init); 73 74 static enum drm_mode_status 75 drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc, 76 const struct drm_display_mode *mode) 77 { 78 struct drm_simple_display_pipe *pipe; 79 80 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc); 81 if (!pipe->funcs || !pipe->funcs->mode_valid) 82 /* Anything goes */ 83 return MODE_OK; 84 85 return pipe->funcs->mode_valid(pipe, mode); 86 } 87 88 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc, 89 struct drm_crtc_state *state) 90 { 91 bool has_primary = state->plane_mask & 92 drm_plane_mask(crtc->primary); 93 94 /* We always want to have an active plane with an active CRTC */ 95 if (has_primary != state->enable) 96 return -EINVAL; 97 98 return drm_atomic_add_affected_planes(state->state, crtc); 99 } 100 101 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc, 102 struct drm_crtc_state *old_state) 103 { 104 struct drm_plane *plane; 105 struct drm_simple_display_pipe *pipe; 106 107 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc); 108 if (!pipe->funcs || !pipe->funcs->enable) 109 return; 110 111 plane = &pipe->plane; 112 pipe->funcs->enable(pipe, crtc->state, plane->state); 113 } 114 115 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc, 116 struct drm_crtc_state *old_state) 117 { 118 struct drm_simple_display_pipe *pipe; 119 120 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc); 121 if (!pipe->funcs || !pipe->funcs->disable) 122 return; 123 124 pipe->funcs->disable(pipe); 125 } 126 127 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = { 128 .mode_valid = drm_simple_kms_crtc_mode_valid, 129 .atomic_check = drm_simple_kms_crtc_check, 130 .atomic_enable = drm_simple_kms_crtc_enable, 131 .atomic_disable = drm_simple_kms_crtc_disable, 132 }; 133 134 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc) 135 { 136 struct drm_simple_display_pipe *pipe; 137 138 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc); 139 if (!pipe->funcs || !pipe->funcs->enable_vblank) 140 return 0; 141 142 return pipe->funcs->enable_vblank(pipe); 143 } 144 145 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc) 146 { 147 struct drm_simple_display_pipe *pipe; 148 149 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc); 150 if (!pipe->funcs || !pipe->funcs->disable_vblank) 151 return; 152 153 pipe->funcs->disable_vblank(pipe); 154 } 155 156 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = { 157 .reset = drm_atomic_helper_crtc_reset, 158 .destroy = drm_crtc_cleanup, 159 .set_config = drm_atomic_helper_set_config, 160 .page_flip = drm_atomic_helper_page_flip, 161 .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state, 162 .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state, 163 .enable_vblank = drm_simple_kms_crtc_enable_vblank, 164 .disable_vblank = drm_simple_kms_crtc_disable_vblank, 165 }; 166 167 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane, 168 struct drm_plane_state *plane_state) 169 { 170 struct drm_simple_display_pipe *pipe; 171 struct drm_crtc_state *crtc_state; 172 int ret; 173 174 pipe = container_of(plane, struct drm_simple_display_pipe, plane); 175 crtc_state = drm_atomic_get_new_crtc_state(plane_state->state, 176 &pipe->crtc); 177 178 ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state, 179 DRM_PLANE_HELPER_NO_SCALING, 180 DRM_PLANE_HELPER_NO_SCALING, 181 false, true); 182 if (ret) 183 return ret; 184 185 if (!plane_state->visible) 186 return 0; 187 188 if (!pipe->funcs || !pipe->funcs->check) 189 return 0; 190 191 return pipe->funcs->check(pipe, plane_state, crtc_state); 192 } 193 194 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane, 195 struct drm_plane_state *old_pstate) 196 { 197 struct drm_simple_display_pipe *pipe; 198 199 pipe = container_of(plane, struct drm_simple_display_pipe, plane); 200 if (!pipe->funcs || !pipe->funcs->update) 201 return; 202 203 pipe->funcs->update(pipe, old_pstate); 204 } 205 206 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane, 207 struct drm_plane_state *state) 208 { 209 struct drm_simple_display_pipe *pipe; 210 211 pipe = container_of(plane, struct drm_simple_display_pipe, plane); 212 if (!pipe->funcs || !pipe->funcs->prepare_fb) 213 return 0; 214 215 return pipe->funcs->prepare_fb(pipe, state); 216 } 217 218 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane, 219 struct drm_plane_state *state) 220 { 221 struct drm_simple_display_pipe *pipe; 222 223 pipe = container_of(plane, struct drm_simple_display_pipe, plane); 224 if (!pipe->funcs || !pipe->funcs->cleanup_fb) 225 return; 226 227 pipe->funcs->cleanup_fb(pipe, state); 228 } 229 230 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane, 231 uint32_t format, 232 uint64_t modifier) 233 { 234 return modifier == DRM_FORMAT_MOD_LINEAR; 235 } 236 237 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = { 238 .prepare_fb = drm_simple_kms_plane_prepare_fb, 239 .cleanup_fb = drm_simple_kms_plane_cleanup_fb, 240 .atomic_check = drm_simple_kms_plane_atomic_check, 241 .atomic_update = drm_simple_kms_plane_atomic_update, 242 }; 243 244 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = { 245 .update_plane = drm_atomic_helper_update_plane, 246 .disable_plane = drm_atomic_helper_disable_plane, 247 .destroy = drm_plane_cleanup, 248 .reset = drm_atomic_helper_plane_reset, 249 .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state, 250 .atomic_destroy_state = drm_atomic_helper_plane_destroy_state, 251 .format_mod_supported = drm_simple_kms_format_mod_supported, 252 }; 253 254 /** 255 * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe 256 * @pipe: simple display pipe object 257 * @bridge: bridge to attach 258 * 259 * Makes it possible to still use the drm_simple_display_pipe helpers when 260 * a DRM bridge has to be used. 261 * 262 * Note that you probably want to initialize the pipe by passing a NULL 263 * connector to drm_simple_display_pipe_init(). 264 * 265 * Returns: 266 * Zero on success, negative error code on failure. 267 */ 268 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe, 269 struct drm_bridge *bridge) 270 { 271 return drm_bridge_attach(&pipe->encoder, bridge, NULL, 0); 272 } 273 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge); 274 275 /** 276 * drm_simple_display_pipe_init - Initialize a simple display pipeline 277 * @dev: DRM device 278 * @pipe: simple display pipe object to initialize 279 * @funcs: callbacks for the display pipe (optional) 280 * @formats: array of supported formats (DRM_FORMAT\_\*) 281 * @format_count: number of elements in @formats 282 * @format_modifiers: array of formats modifiers 283 * @connector: connector to attach and register (optional) 284 * 285 * Sets up a display pipeline which consist of a really simple 286 * plane-crtc-encoder pipe. 287 * 288 * If a connector is supplied, the pipe will be coupled with the provided 289 * connector. You may supply a NULL connector when using drm bridges, that 290 * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()). 291 * 292 * Teardown of a simple display pipe is all handled automatically by the drm 293 * core through calling drm_mode_config_cleanup(). Drivers afterwards need to 294 * release the memory for the structure themselves. 295 * 296 * Returns: 297 * Zero on success, negative error code on failure. 298 */ 299 int drm_simple_display_pipe_init(struct drm_device *dev, 300 struct drm_simple_display_pipe *pipe, 301 const struct drm_simple_display_pipe_funcs *funcs, 302 const uint32_t *formats, unsigned int format_count, 303 const uint64_t *format_modifiers, 304 struct drm_connector *connector) 305 { 306 struct drm_encoder *encoder = &pipe->encoder; 307 struct drm_plane *plane = &pipe->plane; 308 struct drm_crtc *crtc = &pipe->crtc; 309 int ret; 310 311 pipe->connector = connector; 312 pipe->funcs = funcs; 313 314 drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs); 315 ret = drm_universal_plane_init(dev, plane, 0, 316 &drm_simple_kms_plane_funcs, 317 formats, format_count, 318 format_modifiers, 319 DRM_PLANE_TYPE_PRIMARY, NULL); 320 if (ret) 321 return ret; 322 323 drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs); 324 ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL, 325 &drm_simple_kms_crtc_funcs, NULL); 326 if (ret) 327 return ret; 328 329 encoder->possible_crtcs = drm_crtc_mask(crtc); 330 ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE); 331 if (ret || !connector) 332 return ret; 333 334 return drm_connector_attach_encoder(connector, encoder); 335 } 336 EXPORT_SYMBOL(drm_simple_display_pipe_init); 337 338 MODULE_LICENSE("GPL"); 339