gpu/drm/drm_encoder.c

0001 /*
0002  * Copyright (c) 2016 Intel Corporation
0003  *
0004  * Permission to use, copy, modify, distribute, and sell this software and its
0005  * documentation for any purpose is hereby granted without fee, provided that
0006  * the above copyright notice appear in all copies and that both that copyright
0007  * notice and this permission notice appear in supporting documentation, and
0008  * that the name of the copyright holders not be used in advertising or
0009  * publicity pertaining to distribution of the software without specific,
0010  * written prior permission.  The copyright holders make no representations
0011  * about the suitability of this software for any purpose.  It is provided "as
0012  * is" without express or implied warranty.
0013  *
0014  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
0015  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
0016  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
0017  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
0018  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
0019  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
0020  * OF THIS SOFTWARE.
0021  */
0022
0023 #include <linux/export.h>
0024
0025 #include <drm/drm_bridge.h>
0026 #include <drm/drm_device.h>
0027 #include <drm/drm_drv.h>
0028 #include <drm/drm_encoder.h>
0029 #include <drm/drm_managed.h>
0030
0031 #include "drm_crtc_internal.h"
0032
0033 /**
0034  * DOC: overview
0035  *
0036  * Encoders represent the connecting element between the CRTC (as the overall
0037  * pixel pipeline, represented by &struct drm_crtc) and the connectors (as the
0038  * generic sink entity, represented by &struct drm_connector). An encoder takes
0039  * pixel data from a CRTC and converts it to a format suitable for any attached
0040  * connector. Encoders are objects exposed to userspace, originally to allow
0041  * userspace to infer cloning and connector/CRTC restrictions. Unfortunately
0042  * almost all drivers get this wrong, making the uabi pretty much useless. On
0043  * top of that the exposed restrictions are too simple for today's hardware, and
0044  * the recommended way to infer restrictions is by using the
0045  * DRM_MODE_ATOMIC_TEST_ONLY flag for the atomic IOCTL.
0046  *
0047  * Otherwise encoders aren't used in the uapi at all (any modeset request from
0048  * userspace directly connects a connector with a CRTC), drivers are therefore
0049  * free to use them however they wish. Modeset helper libraries make strong use
0050  * of encoders to facilitate code sharing. But for more complex settings it is
0051  * usually better to move shared code into a separate &drm_bridge. Compared to
0052  * encoders, bridges also have the benefit of being purely an internal
0053  * abstraction since they are not exposed to userspace at all.
0054  *
0055  * Encoders are initialized with drm_encoder_init() and cleaned up using
0056  * drm_encoder_cleanup().
0057  */
0058 static const struct drm_prop_enum_list drm_encoder_enum_list[] = {
0059     { DRM_MODE_ENCODER_NONE, "None" },
0060     { DRM_MODE_ENCODER_DAC, "DAC" },
0061     { DRM_MODE_ENCODER_TMDS, "TMDS" },
0062     { DRM_MODE_ENCODER_LVDS, "LVDS" },
0063     { DRM_MODE_ENCODER_TVDAC, "TV" },
0064     { DRM_MODE_ENCODER_VIRTUAL, "Virtual" },
0065     { DRM_MODE_ENCODER_DSI, "DSI" },
0066     { DRM_MODE_ENCODER_DPMST, "DP MST" },
0067     { DRM_MODE_ENCODER_DPI, "DPI" },
0068 };
0069
0070 int drm_encoder_register_all(struct drm_device *dev)
0071 {
0072     struct drm_encoder *encoder;
0073     int ret = 0;
0074
0075     drm_for_each_encoder(encoder, dev) {
0076         if (encoder->funcs && encoder->funcs->late_register)
0077             ret = encoder->funcs->late_register(encoder);
0078         if (ret)
0079             return ret;
0080     }
0081
0082     return 0;
0083 }
0084
0085 void drm_encoder_unregister_all(struct drm_device *dev)
0086 {
0087     struct drm_encoder *encoder;
0088
0089     drm_for_each_encoder(encoder, dev) {
0090         if (encoder->funcs && encoder->funcs->early_unregister)
0091             encoder->funcs->early_unregister(encoder);
0092     }
0093 }
0094
0095 __printf(5, 0)
0096 static int __drm_encoder_init(struct drm_device *dev,
0097                   struct drm_encoder *encoder,
0098                   const struct drm_encoder_funcs *funcs,
0099                   int encoder_type, const char *name, va_list ap)
0100 {
0101     int ret;
0102
0103     /* encoder index is used with 32bit bitmasks */
0104     if (WARN_ON(dev->mode_config.num_encoder >= 32))
0105         return -EINVAL;
0106
0107     ret = drm_mode_object_add(dev, &encoder->base, DRM_MODE_OBJECT_ENCODER);
0108     if (ret)
0109         return ret;
0110
0111     encoder->dev = dev;
0112     encoder->encoder_type = encoder_type;
0113     encoder->funcs = funcs;
0114     if (name) {
0115         encoder->name = kvasprintf(GFP_KERNEL, name, ap);
0116     } else {
0117         encoder->name = kasprintf(GFP_KERNEL, "%s-%d",
0118                       drm_encoder_enum_list[encoder_type].name,
0119                       encoder->base.id);
0120     }
0121     if (!encoder->name) {
0122         ret = -ENOMEM;
0123         goto out_put;
0124     }
0125
0126     INIT_LIST_HEAD(&encoder->bridge_chain);
0127     list_add_tail(&encoder->head, &dev->mode_config.encoder_list);
0128     encoder->index = dev->mode_config.num_encoder++;
0129
0130 out_put:
0131     if (ret)
0132         drm_mode_object_unregister(dev, &encoder->base);
0133
0134     return ret;
0135 }
0136
0137 /**
0138  * drm_encoder_init - Init a preallocated encoder
0139  * @dev: drm device
0140  * @encoder: the encoder to init
0141  * @funcs: callbacks for this encoder
0142  * @encoder_type: user visible type of the encoder
0143  * @name: printf style format string for the encoder name, or NULL for default name
0144  *
0145  * Initializes a preallocated encoder. Encoder should be subclassed as part of
0146  * driver encoder objects. At driver unload time the driver's
0147  * &drm_encoder_funcs.destroy hook should call drm_encoder_cleanup() and kfree()
0148  * the encoder structure. The encoder structure should not be allocated with
0149  * devm_kzalloc().
0150  *
0151  * Note: consider using drmm_encoder_alloc() instead of drm_encoder_init() to
0152  * let the DRM managed resource infrastructure take care of cleanup and
0153  * deallocation.
0154  *
0155  * Returns:
0156  * Zero on success, error code on failure.
0157  */
0158 int drm_encoder_init(struct drm_device *dev,
0159              struct drm_encoder *encoder,
0160              const struct drm_encoder_funcs *funcs,
0161              int encoder_type, const char *name, ...)
0162 {
0163     va_list ap;
0164     int ret;
0165
0166     WARN_ON(!funcs->destroy);
0167
0168     va_start(ap, name);
0169     ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
0170     va_end(ap);
0171
0172     return ret;
0173 }
0174 EXPORT_SYMBOL(drm_encoder_init);
0175
0176 /**
0177  * drm_encoder_cleanup - cleans up an initialised encoder
0178  * @encoder: encoder to cleanup
0179  *
0180  * Cleans up the encoder but doesn't free the object.
0181  */
0182 void drm_encoder_cleanup(struct drm_encoder *encoder)
0183 {
0184     struct drm_device *dev = encoder->dev;
0185     struct drm_bridge *bridge, *next;
0186
0187     /* Note that the encoder_list is considered to be static; should we
0188      * remove the drm_encoder at runtime we would have to decrement all
0189      * the indices on the drm_encoder after us in the encoder_list.
0190      */
0191
0192     list_for_each_entry_safe(bridge, next, &encoder->bridge_chain,
0193                  chain_node)
0194         drm_bridge_detach(bridge);
0195
0196     drm_mode_object_unregister(dev, &encoder->base);
0197     kfree(encoder->name);
0198     list_del(&encoder->head);
0199     dev->mode_config.num_encoder--;
0200
0201     memset(encoder, 0, sizeof(*encoder));
0202 }
0203 EXPORT_SYMBOL(drm_encoder_cleanup);
0204
0205 static void drmm_encoder_alloc_release(struct drm_device *dev, void *ptr)
0206 {
0207     struct drm_encoder *encoder = ptr;
0208
0209     if (WARN_ON(!encoder->dev))
0210         return;
0211
0212     drm_encoder_cleanup(encoder);
0213 }
0214
0215 void *__drmm_encoder_alloc(struct drm_device *dev, size_t size, size_t offset,
0216                const struct drm_encoder_funcs *funcs,
0217                int encoder_type, const char *name, ...)
0218 {
0219     void *container;
0220     struct drm_encoder *encoder;
0221     va_list ap;
0222     int ret;
0223
0224     if (WARN_ON(funcs && funcs->destroy))
0225         return ERR_PTR(-EINVAL);
0226
0227     container = drmm_kzalloc(dev, size, GFP_KERNEL);
0228     if (!container)
0229         return ERR_PTR(-ENOMEM);
0230
0231     encoder = container + offset;
0232
0233     va_start(ap, name);
0234     ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
0235     va_end(ap);
0236     if (ret)
0237         return ERR_PTR(ret);
0238
0239     ret = drmm_add_action_or_reset(dev, drmm_encoder_alloc_release, encoder);
0240     if (ret)
0241         return ERR_PTR(ret);
0242
0243     return container;
0244 }
0245 EXPORT_SYMBOL(__drmm_encoder_alloc);
0246
0247 static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder)
0248 {
0249     struct drm_connector *connector;
0250     struct drm_device *dev = encoder->dev;
0251     bool uses_atomic = false;
0252     struct drm_connector_list_iter conn_iter;
0253
0254     /* For atomic drivers only state objects are synchronously updated and
0255      * protected by modeset locks, so check those first. */
0256     drm_connector_list_iter_begin(dev, &conn_iter);
0257     drm_for_each_connector_iter(connector, &conn_iter) {
0258         if (!connector->state)
0259             continue;
0260
0261         uses_atomic = true;
0262
0263         if (connector->state->best_encoder != encoder)
0264             continue;
0265
0266         drm_connector_list_iter_end(&conn_iter);
0267         return connector->state->crtc;
0268     }
0269     drm_connector_list_iter_end(&conn_iter);
0270
0271     /* Don't return stale data (e.g. pending async disable). */
0272     if (uses_atomic)
0273         return NULL;
0274
0275     return encoder->crtc;
0276 }
0277
0278 int drm_mode_getencoder(struct drm_device *dev, void *data,
0279             struct drm_file *file_priv)
0280 {
0281     struct drm_mode_get_encoder *enc_resp = data;
0282     struct drm_encoder *encoder;
0283     struct drm_crtc *crtc;
0284
0285     if (!drm_core_check_feature(dev, DRIVER_MODESET))
0286         return -EOPNOTSUPP;
0287
0288     encoder = drm_encoder_find(dev, file_priv, enc_resp->encoder_id);
0289     if (!encoder)
0290         return -ENOENT;
0291
0292     drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
0293     crtc = drm_encoder_get_crtc(encoder);
0294     if (crtc && drm_lease_held(file_priv, crtc->base.id))
0295         enc_resp->crtc_id = crtc->base.id;
0296     else
0297         enc_resp->crtc_id = 0;
0298     drm_modeset_unlock(&dev->mode_config.connection_mutex);
0299
0300     enc_resp->encoder_type = encoder->encoder_type;
0301     enc_resp->encoder_id = encoder->base.id;
0302     enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
0303                               encoder->possible_crtcs);
0304     enc_resp->possible_clones = encoder->possible_clones;
0305
0306     return 0;
0307 }