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 destroy hook in &drm_encoder_funcs. 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 ret = drm_mode_object_get(dev, &encoder->base, DRM_MODE_OBJECT_ENCODER); 114 if (ret) 115 return ret; 116 117 encoder->dev = dev; 118 encoder->encoder_type = encoder_type; 119 encoder->funcs = funcs; 120 if (name) { 121 va_list ap; 122 123 va_start(ap, name); 124 encoder->name = kvasprintf(GFP_KERNEL, name, ap); 125 va_end(ap); 126 } else { 127 encoder->name = kasprintf(GFP_KERNEL, "%s-%d", 128 drm_encoder_enum_list[encoder_type].name, 129 encoder->base.id); 130 } 131 if (!encoder->name) { 132 ret = -ENOMEM; 133 goto out_put; 134 } 135 136 list_add_tail(&encoder->head, &dev->mode_config.encoder_list); 137 encoder->index = dev->mode_config.num_encoder++; 138 139 out_put: 140 if (ret) 141 drm_mode_object_unregister(dev, &encoder->base); 142 143 return ret; 144 } 145 EXPORT_SYMBOL(drm_encoder_init); 146 147 /** 148 * drm_encoder_cleanup - cleans up an initialised encoder 149 * @encoder: encoder to cleanup 150 * 151 * Cleans up the encoder but doesn't free the object. 152 */ 153 void drm_encoder_cleanup(struct drm_encoder *encoder) 154 { 155 struct drm_device *dev = encoder->dev; 156 157 /* Note that the encoder_list is considered to be static; should we 158 * remove the drm_encoder at runtime we would have to decrement all 159 * the indices on the drm_encoder after us in the encoder_list. 160 */ 161 162 drm_mode_object_unregister(dev, &encoder->base); 163 kfree(encoder->name); 164 list_del(&encoder->head); 165 dev->mode_config.num_encoder--; 166 167 memset(encoder, 0, sizeof(*encoder)); 168 } 169 EXPORT_SYMBOL(drm_encoder_cleanup); 170 171 static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder) 172 { 173 struct drm_connector *connector; 174 struct drm_device *dev = encoder->dev; 175 bool uses_atomic = false; 176 177 /* For atomic drivers only state objects are synchronously updated and 178 * protected by modeset locks, so check those first. */ 179 drm_for_each_connector(connector, dev) { 180 if (!connector->state) 181 continue; 182 183 uses_atomic = true; 184 185 if (connector->state->best_encoder != encoder) 186 continue; 187 188 return connector->state->crtc; 189 } 190 191 /* Don't return stale data (e.g. pending async disable). */ 192 if (uses_atomic) 193 return NULL; 194 195 return encoder->crtc; 196 } 197 198 int drm_mode_getencoder(struct drm_device *dev, void *data, 199 struct drm_file *file_priv) 200 { 201 struct drm_mode_get_encoder *enc_resp = data; 202 struct drm_encoder *encoder; 203 struct drm_crtc *crtc; 204 205 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 206 return -EINVAL; 207 208 encoder = drm_encoder_find(dev, enc_resp->encoder_id); 209 if (!encoder) 210 return -ENOENT; 211 212 drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); 213 crtc = drm_encoder_get_crtc(encoder); 214 if (crtc) 215 enc_resp->crtc_id = crtc->base.id; 216 else 217 enc_resp->crtc_id = 0; 218 drm_modeset_unlock(&dev->mode_config.connection_mutex); 219 220 enc_resp->encoder_type = encoder->encoder_type; 221 enc_resp->encoder_id = encoder->base.id; 222 enc_resp->possible_crtcs = encoder->possible_crtcs; 223 enc_resp->possible_clones = encoder->possible_clones; 224 225 return 0; 226 } 227