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