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 #include <drm/drmP.h> 25 #include <drm/drm_encoder.h> 26 27 #include "drm_crtc_internal.h" 28 29 /** 30 * DOC: overview 31 * 32 * Encoders represent the connecting element between the CRTC (as the overall 33 * pixel pipeline, represented by &struct drm_crtc) and the connectors (as the 34 * generic sink entity, represented by &struct drm_connector). An encoder takes 35 * pixel data from a CRTC and converts it to a format suitable for any attached 36 * connector. Encoders are objects exposed to userspace, originally to allow 37 * userspace to infer cloning and connector/CRTC restrictions. Unfortunately 38 * almost all drivers get this wrong, making the uabi pretty much useless. On 39 * top of that the exposed restrictions are too simple for today's hardware, and 40 * the recommended way to infer restrictions is by using the 41 * DRM_MODE_ATOMIC_TEST_ONLY flag for the atomic IOCTL. 42 * 43 * Otherwise encoders aren't used in the uapi at all (any modeset request from 44 * userspace directly connects a connector with a CRTC), drivers are therefore 45 * free to use them however they wish. Modeset helper libraries make strong use 46 * of encoders to facilitate code sharing. But for more complex settings it is 47 * usually better to move shared code into a separate &drm_bridge. Compared to 48 * encoders, bridges also have the benefit of being purely an internal 49 * abstraction since they are not exposed to userspace at all. 50 * 51 * Encoders are initialized with drm_encoder_init() and cleaned up using 52 * drm_encoder_cleanup(). 53 */ 54 static const struct drm_prop_enum_list drm_encoder_enum_list[] = { 55 { DRM_MODE_ENCODER_NONE, "None" }, 56 { DRM_MODE_ENCODER_DAC, "DAC" }, 57 { DRM_MODE_ENCODER_TMDS, "TMDS" }, 58 { DRM_MODE_ENCODER_LVDS, "LVDS" }, 59 { DRM_MODE_ENCODER_TVDAC, "TV" }, 60 { DRM_MODE_ENCODER_VIRTUAL, "Virtual" }, 61 { DRM_MODE_ENCODER_DSI, "DSI" }, 62 { DRM_MODE_ENCODER_DPMST, "DP MST" }, 63 { DRM_MODE_ENCODER_DPI, "DPI" }, 64 }; 65 66 int drm_encoder_register_all(struct drm_device *dev) 67 { 68 struct drm_encoder *encoder; 69 int ret = 0; 70 71 drm_for_each_encoder(encoder, dev) { 72 if (encoder->funcs->late_register) 73 ret = encoder->funcs->late_register(encoder); 74 if (ret) 75 return ret; 76 } 77 78 return 0; 79 } 80 81 void drm_encoder_unregister_all(struct drm_device *dev) 82 { 83 struct drm_encoder *encoder; 84 85 drm_for_each_encoder(encoder, dev) { 86 if (encoder->funcs->early_unregister) 87 encoder->funcs->early_unregister(encoder); 88 } 89 } 90 91 /** 92 * drm_encoder_init - Init a preallocated encoder 93 * @dev: drm device 94 * @encoder: the encoder to init 95 * @funcs: callbacks for this encoder 96 * @encoder_type: user visible type of the encoder 97 * @name: printf style format string for the encoder name, or NULL for default name 98 * 99 * Initialises a preallocated encoder. Encoder should be subclassed as part of 100 * driver encoder objects. At driver unload time drm_encoder_cleanup() should be 101 * called from the driver's &drm_encoder_funcs.destroy hook. 102 * 103 * Returns: 104 * Zero on success, error code on failure. 105 */ 106 int drm_encoder_init(struct drm_device *dev, 107 struct drm_encoder *encoder, 108 const struct drm_encoder_funcs *funcs, 109 int encoder_type, const char *name, ...) 110 { 111 int ret; 112 113 /* encoder index is used with 32bit bitmasks */ 114 if (WARN_ON(dev->mode_config.num_encoder >= 32)) 115 return -EINVAL; 116 117 ret = drm_mode_object_add(dev, &encoder->base, DRM_MODE_OBJECT_ENCODER); 118 if (ret) 119 return ret; 120 121 encoder->dev = dev; 122 encoder->encoder_type = encoder_type; 123 encoder->funcs = funcs; 124 if (name) { 125 va_list ap; 126 127 va_start(ap, name); 128 encoder->name = kvasprintf(GFP_KERNEL, name, ap); 129 va_end(ap); 130 } else { 131 encoder->name = kasprintf(GFP_KERNEL, "%s-%d", 132 drm_encoder_enum_list[encoder_type].name, 133 encoder->base.id); 134 } 135 if (!encoder->name) { 136 ret = -ENOMEM; 137 goto out_put; 138 } 139 140 list_add_tail(&encoder->head, &dev->mode_config.encoder_list); 141 encoder->index = dev->mode_config.num_encoder++; 142 143 out_put: 144 if (ret) 145 drm_mode_object_unregister(dev, &encoder->base); 146 147 return ret; 148 } 149 EXPORT_SYMBOL(drm_encoder_init); 150 151 /** 152 * drm_encoder_cleanup - cleans up an initialised encoder 153 * @encoder: encoder to cleanup 154 * 155 * Cleans up the encoder but doesn't free the object. 156 */ 157 void drm_encoder_cleanup(struct drm_encoder *encoder) 158 { 159 struct drm_device *dev = encoder->dev; 160 161 /* Note that the encoder_list is considered to be static; should we 162 * remove the drm_encoder at runtime we would have to decrement all 163 * the indices on the drm_encoder after us in the encoder_list. 164 */ 165 166 if (encoder->bridge) { 167 struct drm_bridge *bridge = encoder->bridge; 168 struct drm_bridge *next; 169 170 while (bridge) { 171 next = bridge->next; 172 drm_bridge_detach(bridge); 173 bridge = next; 174 } 175 } 176 177 drm_mode_object_unregister(dev, &encoder->base); 178 kfree(encoder->name); 179 list_del(&encoder->head); 180 dev->mode_config.num_encoder--; 181 182 memset(encoder, 0, sizeof(*encoder)); 183 } 184 EXPORT_SYMBOL(drm_encoder_cleanup); 185 186 static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder) 187 { 188 struct drm_connector *connector; 189 struct drm_device *dev = encoder->dev; 190 bool uses_atomic = false; 191 struct drm_connector_list_iter conn_iter; 192 193 /* For atomic drivers only state objects are synchronously updated and 194 * protected by modeset locks, so check those first. */ 195 drm_connector_list_iter_begin(dev, &conn_iter); 196 drm_for_each_connector_iter(connector, &conn_iter) { 197 if (!connector->state) 198 continue; 199 200 uses_atomic = true; 201 202 if (connector->state->best_encoder != encoder) 203 continue; 204 205 drm_connector_list_iter_end(&conn_iter); 206 return connector->state->crtc; 207 } 208 drm_connector_list_iter_end(&conn_iter); 209 210 /* Don't return stale data (e.g. pending async disable). */ 211 if (uses_atomic) 212 return NULL; 213 214 return encoder->crtc; 215 } 216 217 int drm_mode_getencoder(struct drm_device *dev, void *data, 218 struct drm_file *file_priv) 219 { 220 struct drm_mode_get_encoder *enc_resp = data; 221 struct drm_encoder *encoder; 222 struct drm_crtc *crtc; 223 224 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 225 return -EOPNOTSUPP; 226 227 encoder = drm_encoder_find(dev, file_priv, enc_resp->encoder_id); 228 if (!encoder) 229 return -ENOENT; 230 231 drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); 232 crtc = drm_encoder_get_crtc(encoder); 233 if (crtc && drm_lease_held(file_priv, crtc->base.id)) 234 enc_resp->crtc_id = crtc->base.id; 235 else 236 enc_resp->crtc_id = 0; 237 drm_modeset_unlock(&dev->mode_config.connection_mutex); 238 239 enc_resp->encoder_type = encoder->encoder_type; 240 enc_resp->encoder_id = encoder->base.id; 241 enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv, 242 encoder->possible_crtcs); 243 enc_resp->possible_clones = encoder->possible_clones; 244 245 return 0; 246 } 247