include/drm/drm_encoder.h

   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 #ifndef __DRM_ENCODER_H__
  24 #define __DRM_ENCODER_H__
  25
  26 #include <linux/list.h>
  27 #include <linux/ctype.h>
  28 #include <drm/drm_crtc.h>
  29 #include <drm/drm_mode.h>
  30 #include <drm/drm_mode_object.h>
  31
  32 struct drm_encoder;
  33
  34 /**
  35  * struct drm_encoder_funcs - encoder controls
  36  *
  37  * Encoders sit between CRTCs and connectors.
  38  */
  39 struct drm_encoder_funcs {
  40         /**
  41          * @reset:
  42          *
  43          * Reset encoder hardware and software state to off. This function isn't
  44          * called by the core directly, only through drm_mode_config_reset().
  45          * It's not a helper hook only for historical reasons.
  46          */
  47         void (*reset)(struct drm_encoder *encoder);
  48
  49         /**
  50          * @destroy:
  51          *
  52          * Clean up encoder resources. This is only called at driver unload time
  53          * through drm_mode_config_cleanup() since an encoder cannot be
  54          * hotplugged in DRM.
  55          */
  56         void (*destroy)(struct drm_encoder *encoder);
  57
  58         /**
  59          * @late_register:
  60          *
  61          * This optional hook can be used to register additional userspace
  62          * interfaces attached to the encoder like debugfs interfaces.
  63          * It is called late in the driver load sequence from drm_dev_register().
  64          * Everything added from this callback should be unregistered in
  65          * the early_unregister callback.
  66          *
  67          * Returns:
  68          *
  69          * 0 on success, or a negative error code on failure.
  70          */
  71         int (*late_register)(struct drm_encoder *encoder);
  72
  73         /**
  74          * @early_unregister:
  75          *
  76          * This optional hook should be used to unregister the additional
  77          * userspace interfaces attached to the encoder from
  78          * @late_register. It is called from drm_dev_unregister(),
  79          * early in the driver unload sequence to disable userspace access
  80          * before data structures are torndown.
  81          */
  82         void (*early_unregister)(struct drm_encoder *encoder);
  83 };
  84
  85 /**
  86  * struct drm_encoder - central DRM encoder structure
  87  * @dev: parent DRM device
  88  * @head: list management
  89  * @base: base KMS object
  90  * @name: human readable name, can be overwritten by the driver
  91  * @crtc: currently bound CRTC
  92  * @bridge: bridge associated to the encoder
  93  * @funcs: control functions
  94  * @helper_private: mid-layer private data
  95  *
  96  * CRTCs drive pixels to encoders, which convert them into signals
  97  * appropriate for a given connector or set of connectors.
  98  */
  99 struct drm_encoder {
 100         struct drm_device *dev;
 101         struct list_head head;
 102
 103         struct drm_mode_object base;
 104         char *name;
 105         /**
 106          * @encoder_type:
 107          *
 108          * One of the DRM_MODE_ENCODER_<foo> types in drm_mode.h. The following
 109          * encoder types are defined thus far:
 110          *
 111          * - DRM_MODE_ENCODER_DAC for VGA and analog on DVI-I/DVI-A.
 112          *
 113          * - DRM_MODE_ENCODER_TMDS for DVI, HDMI and (embedded) DisplayPort.
 114          *
 115          * - DRM_MODE_ENCODER_LVDS for display panels, or in general any panel
 116          *   with a proprietary parallel connector.
 117          *
 118          * - DRM_MODE_ENCODER_TVDAC for TV output (Composite, S-Video,
 119          *   Component, SCART).
 120          *
 121          * - DRM_MODE_ENCODER_VIRTUAL for virtual machine displays
 122          *
 123          * - DRM_MODE_ENCODER_DSI for panels connected using the DSI serial bus.
 124          *
 125          * - DRM_MODE_ENCODER_DPI for panels connected using the DPI parallel
 126          *   bus.
 127          *
 128          * - DRM_MODE_ENCODER_DPMST for special fake encoders used to allow
 129          *   mutliple DP MST streams to share one physical encoder.
 130          */
 131         int encoder_type;
 132
 133         /**
 134          * @index: Position inside the mode_config.list, can be used as an array
 135          * index. It is invariant over the lifetime of the encoder.
 136          */
 137         unsigned index;
 138
 139         /**
 140          * @possible_crtcs: Bitmask of potential CRTC bindings, using
 141          * drm_crtc_index() as the index into the bitfield. The driver must set
 142          * the bits for all &drm_crtc objects this encoder can be connected to
 143          * before calling drm_encoder_init().
 144          *
 145          * In reality almost every driver gets this wrong.
 146          *
 147          * Note that since CRTC objects can't be hotplugged the assigned indices
 148          * are stable and hence known before registering all objects.
 149          */
 150         uint32_t possible_crtcs;
 151
 152         /**
 153          * @possible_clones: Bitmask of potential sibling encoders for cloning,
 154          * using drm_encoder_index() as the index into the bitfield. The driver
 155          * must set the bits for all &drm_encoder objects which can clone a
 156          * &drm_crtc together with this encoder before calling
 157          * drm_encoder_init(). Drivers should set the bit representing the
 158          * encoder itself, too. Cloning bits should be set such that when two
 159          * encoders can be used in a cloned configuration, they both should have
 160          * each another bits set.
 161          *
 162          * In reality almost every driver gets this wrong.
 163          *
 164          * Note that since encoder objects can't be hotplugged the assigned indices
 165          * are stable and hence known before registering all objects.
 166          */
 167         uint32_t possible_clones;
 168
 169         struct drm_crtc *crtc;
 170         struct drm_bridge *bridge;
 171         const struct drm_encoder_funcs *funcs;
 172         const struct drm_encoder_helper_funcs *helper_private;
 173 };
 174
 175 #define obj_to_encoder(x) container_of(x, struct drm_encoder, base)
 176
 177 __printf(5, 6)
 178 int drm_encoder_init(struct drm_device *dev,
 179                      struct drm_encoder *encoder,
 180                      const struct drm_encoder_funcs *funcs,
 181                      int encoder_type, const char *name, ...);
 182
 183 /**
 184  * drm_encoder_index - find the index of a registered encoder
 185  * @encoder: encoder to find index for
 186  *
 187  * Given a registered encoder, return the index of that encoder within a DRM
 188  * device's list of encoders.
 189  */
 190 static inline unsigned int drm_encoder_index(struct drm_encoder *encoder)
 191 {
 192         return encoder->index;
 193 }
 194
 195 /**
 196  * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
 197  * @encoder: encoder to test
 198  * @crtc: crtc to test
 199  *
 200  * Returns false if @encoder can't be driven by @crtc, true otherwise.
 201  */
 202 static inline bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
 203                                        struct drm_crtc *crtc)
 204 {
 205         return !!(encoder->possible_crtcs & drm_crtc_mask(crtc));
 206 }
 207
 208 /**
 209  * drm_encoder_find - find a &drm_encoder
 210  * @dev: DRM device
 211  * @id: encoder id
 212  *
 213  * Returns the encoder with @id, NULL if it doesn't exist. Simple wrapper around
 214  * drm_mode_object_find().
 215  */
 216 static inline struct drm_encoder *drm_encoder_find(struct drm_device *dev,
 217                                                    uint32_t id)
 218 {
 219         struct drm_mode_object *mo;
 220
 221         mo = drm_mode_object_find(dev, id, DRM_MODE_OBJECT_ENCODER);
 222
 223         return mo ? obj_to_encoder(mo) : NULL;
 224 }
 225
 226 void drm_encoder_cleanup(struct drm_encoder *encoder);
 227
 228 /**
 229  * drm_for_each_encoder_mask - iterate over encoders specified by bitmask
 230  * @encoder: the loop cursor
 231  * @dev: the DRM device
 232  * @encoder_mask: bitmask of encoder indices
 233  *
 234  * Iterate over all encoders specified by bitmask.
 235  */
 236 #define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
 237         list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
 238                 for_each_if ((encoder_mask) & (1 << drm_encoder_index(encoder)))
 239
 240 /**
 241  * drm_for_each_encoder - iterate over all encoders
 242  * @encoder: the loop cursor
 243  * @dev: the DRM device
 244  *
 245  * Iterate over all encoders of @dev.
 246  */
 247 #define drm_for_each_encoder(encoder, dev) \
 248         list_for_each_entry(encoder, &(dev)->mode_config.encoder_list, head)
 249
 250 #endif