1 /* 2 * Copyright (c) 2016 Intel Corporation 3 * 4 * Permission to use, copy, modify, distribute, and sell this software and its 5 * documentation for any purpose is hereby granted without fee, provided that 6 * the above copyright notice appear in all copies and that both that copyright 7 * notice and this permission notice appear in supporting documentation, and 8 * that the name of the copyright holders not be used in advertising or 9 * publicity pertaining to distribution of the software without specific, 10 * written prior permission. The copyright holders make no representations 11 * about the suitability of this software for any purpose. It is provided "as 12 * is" without express or implied warranty. 13 * 14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO 16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR 17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, 18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 20 * OF THIS SOFTWARE. 21 */ 22 23 #include <linux/export.h> 24 25 #include <drm/drm_device.h> 26 #include <drm/drm_drv.h> 27 #include <drm/drm_encoder.h> 28 29 #include "drm_crtc_internal.h" 30 31 /** 32 * DOC: overview 33 * 34 * Encoders represent the connecting element between the CRTC (as the overall 35 * pixel pipeline, represented by &struct drm_crtc) and the connectors (as the 36 * generic sink entity, represented by &struct drm_connector). An encoder takes 37 * pixel data from a CRTC and converts it to a format suitable for any attached 38 * connector. Encoders are objects exposed to userspace, originally to allow 39 * userspace to infer cloning and connector/CRTC restrictions. Unfortunately 40 * almost all drivers get this wrong, making the uabi pretty much useless. On 41 * top of that the exposed restrictions are too simple for today's hardware, and 42 * the recommended way to infer restrictions is by using the 43 * DRM_MODE_ATOMIC_TEST_ONLY flag for the atomic IOCTL. 44 * 45 * Otherwise encoders aren't used in the uapi at all (any modeset request from 46 * userspace directly connects a connector with a CRTC), drivers are therefore 47 * free to use them however they wish. Modeset helper libraries make strong use 48 * of encoders to facilitate code sharing. But for more complex settings it is 49 * usually better to move shared code into a separate &drm_bridge. Compared to 50 * encoders, bridges also have the benefit of being purely an internal 51 * abstraction since they are not exposed to userspace at all. 52 * 53 * Encoders are initialized with drm_encoder_init() and cleaned up using 54 * drm_encoder_cleanup(). 55 */ 56 static const struct drm_prop_enum_list drm_encoder_enum_list[] = { 57 { DRM_MODE_ENCODER_NONE, "None" }, 58 { DRM_MODE_ENCODER_DAC, "DAC" }, 59 { DRM_MODE_ENCODER_TMDS, "TMDS" }, 60 { DRM_MODE_ENCODER_LVDS, "LVDS" }, 61 { DRM_MODE_ENCODER_TVDAC, "TV" }, 62 { DRM_MODE_ENCODER_VIRTUAL, "Virtual" }, 63 { DRM_MODE_ENCODER_DSI, "DSI" }, 64 { DRM_MODE_ENCODER_DPMST, "DP MST" }, 65 { DRM_MODE_ENCODER_DPI, "DPI" }, 66 }; 67 68 int drm_encoder_register_all(struct drm_device *dev) 69 { 70 struct drm_encoder *encoder; 71 int ret = 0; 72 73 drm_for_each_encoder(encoder, dev) { 74 if (encoder->funcs->late_register) 75 ret = encoder->funcs->late_register(encoder); 76 if (ret) 77 return ret; 78 } 79 80 return 0; 81 } 82 83 void drm_encoder_unregister_all(struct drm_device *dev) 84 { 85 struct drm_encoder *encoder; 86 87 drm_for_each_encoder(encoder, dev) { 88 if (encoder->funcs->early_unregister) 89 encoder->funcs->early_unregister(encoder); 90 } 91 } 92 93 /** 94 * drm_encoder_init - Init a preallocated encoder 95 * @dev: drm device 96 * @encoder: the encoder to init 97 * @funcs: callbacks for this encoder 98 * @encoder_type: user visible type of the encoder 99 * @name: printf style format string for the encoder name, or NULL for default name 100 * 101 * Initialises a preallocated encoder. Encoder should be subclassed as part of 102 * driver encoder objects. At driver unload time drm_encoder_cleanup() should be 103 * called from the driver's &drm_encoder_funcs.destroy hook. 104 * 105 * Returns: 106 * Zero on success, error code on failure. 107 */ 108 int drm_encoder_init(struct drm_device *dev, 109 struct drm_encoder *encoder, 110 const struct drm_encoder_funcs *funcs, 111 int encoder_type, const char *name, ...) 112 { 113 int ret; 114 115 /* encoder index is used with 32bit bitmasks */ 116 if (WARN_ON(dev->mode_config.num_encoder >= 32)) 117 return -EINVAL; 118 119 ret = drm_mode_object_add(dev, &encoder->base, DRM_MODE_OBJECT_ENCODER); 120 if (ret) 121 return ret; 122 123 encoder->dev = dev; 124 encoder->encoder_type = encoder_type; 125 encoder->funcs = funcs; 126 if (name) { 127 va_list ap; 128 129 va_start(ap, name); 130 encoder->name = kvasprintf(GFP_KERNEL, name, ap); 131 va_end(ap); 132 } else { 133 encoder->name = kasprintf(GFP_KERNEL, "%s-%d", 134 drm_encoder_enum_list[encoder_type].name, 135 encoder->base.id); 136 } 137 if (!encoder->name) { 138 ret = -ENOMEM; 139 goto out_put; 140 } 141 142 list_add_tail(&encoder->head, &dev->mode_config.encoder_list); 143 encoder->index = dev->mode_config.num_encoder++; 144 145 out_put: 146 if (ret) 147 drm_mode_object_unregister(dev, &encoder->base); 148 149 return ret; 150 } 151 EXPORT_SYMBOL(drm_encoder_init); 152 153 /** 154 * drm_encoder_cleanup - cleans up an initialised encoder 155 * @encoder: encoder to cleanup 156 * 157 * Cleans up the encoder but doesn't free the object. 158 */ 159 void drm_encoder_cleanup(struct drm_encoder *encoder) 160 { 161 struct drm_device *dev = encoder->dev; 162 163 /* Note that the encoder_list is considered to be static; should we 164 * remove the drm_encoder at runtime we would have to decrement all 165 * the indices on the drm_encoder after us in the encoder_list. 166 */ 167 168 if (encoder->bridge) { 169 struct drm_bridge *bridge = encoder->bridge; 170 struct drm_bridge *next; 171 172 while (bridge) { 173 next = bridge->next; 174 drm_bridge_detach(bridge); 175 bridge = next; 176 } 177 } 178 179 drm_mode_object_unregister(dev, &encoder->base); 180 kfree(encoder->name); 181 list_del(&encoder->head); 182 dev->mode_config.num_encoder--; 183 184 memset(encoder, 0, sizeof(*encoder)); 185 } 186 EXPORT_SYMBOL(drm_encoder_cleanup); 187 188 static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder) 189 { 190 struct drm_connector *connector; 191 struct drm_device *dev = encoder->dev; 192 bool uses_atomic = false; 193 struct drm_connector_list_iter conn_iter; 194 195 /* For atomic drivers only state objects are synchronously updated and 196 * protected by modeset locks, so check those first. */ 197 drm_connector_list_iter_begin(dev, &conn_iter); 198 drm_for_each_connector_iter(connector, &conn_iter) { 199 if (!connector->state) 200 continue; 201 202 uses_atomic = true; 203 204 if (connector->state->best_encoder != encoder) 205 continue; 206 207 drm_connector_list_iter_end(&conn_iter); 208 return connector->state->crtc; 209 } 210 drm_connector_list_iter_end(&conn_iter); 211 212 /* Don't return stale data (e.g. pending async disable). */ 213 if (uses_atomic) 214 return NULL; 215 216 return encoder->crtc; 217 } 218 219 int drm_mode_getencoder(struct drm_device *dev, void *data, 220 struct drm_file *file_priv) 221 { 222 struct drm_mode_get_encoder *enc_resp = data; 223 struct drm_encoder *encoder; 224 struct drm_crtc *crtc; 225 226 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 227 return -EOPNOTSUPP; 228 229 encoder = drm_encoder_find(dev, file_priv, enc_resp->encoder_id); 230 if (!encoder) 231 return -ENOENT; 232 233 drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); 234 crtc = drm_encoder_get_crtc(encoder); 235 if (crtc && drm_lease_held(file_priv, crtc->base.id)) 236 enc_resp->crtc_id = crtc->base.id; 237 else 238 enc_resp->crtc_id = 0; 239 drm_modeset_unlock(&dev->mode_config.connection_mutex); 240 241 enc_resp->encoder_type = encoder->encoder_type; 242 enc_resp->encoder_id = encoder->base.id; 243 enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv, 244 encoder->possible_crtcs); 245 enc_resp->possible_clones = encoder->possible_clones; 246 247 return 0; 248 } 249