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#include <drm/drm_util.h>
 32
 33struct drm_encoder;
 34
 35/**
 36 * struct drm_encoder_funcs - encoder controls
 37 *
 38 * Encoders sit between CRTCs and connectors.
 39 */
 40struct drm_encoder_funcs {
 41	/**
 42	 * @reset:
 43	 *
 44	 * Reset encoder hardware and software state to off. This function isn't
 45	 * called by the core directly, only through drm_mode_config_reset().
 46	 * It's not a helper hook only for historical reasons.
 47	 */
 48	void (*reset)(struct drm_encoder *encoder);
 49
 50	/**
 51	 * @destroy:
 52	 *
 53	 * Clean up encoder resources. This is only called at driver unload time
 54	 * through drm_mode_config_cleanup() since an encoder cannot be
 55	 * hotplugged in DRM.
 56	 */
 57	void (*destroy)(struct drm_encoder *encoder);
 58
 59	/**
 60	 * @late_register:
 61	 *
 62	 * This optional hook can be used to register additional userspace
 63	 * interfaces attached to the encoder like debugfs interfaces.
 64	 * It is called late in the driver load sequence from drm_dev_register().
 65	 * Everything added from this callback should be unregistered in
 66	 * the early_unregister callback.
 67	 *
 68	 * Returns:
 69	 *
 70	 * 0 on success, or a negative error code on failure.
 71	 */
 72	int (*late_register)(struct drm_encoder *encoder);
 73
 74	/**
 75	 * @early_unregister:
 76	 *
 77	 * This optional hook should be used to unregister the additional
 78	 * userspace interfaces attached to the encoder from
 79	 * @late_register. It is called from drm_dev_unregister(),
 80	 * early in the driver unload sequence to disable userspace access
 81	 * before data structures are torndown.
 82	 */
 83	void (*early_unregister)(struct drm_encoder *encoder);
 84};
 85
 86/**
 87 * struct drm_encoder - central DRM encoder structure
 88 * @dev: parent DRM device
 89 * @head: list management
 90 * @base: base KMS object
 91 * @name: human readable name, can be overwritten by the driver
 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 */
 99struct 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	/**
170	 * @crtc: Currently bound CRTC, only really meaningful for non-atomic
171	 * drivers.  Atomic drivers should instead check
172	 * &drm_connector_state.crtc.
173	 */
174	struct drm_crtc *crtc;
175	struct drm_bridge *bridge;
176	const struct drm_encoder_funcs *funcs;
177	const struct drm_encoder_helper_funcs *helper_private;
178};
179
180#define obj_to_encoder(x) container_of(x, struct drm_encoder, base)
181
182__printf(5, 6)
183int drm_encoder_init(struct drm_device *dev,
184		     struct drm_encoder *encoder,
185		     const struct drm_encoder_funcs *funcs,
186		     int encoder_type, const char *name, ...);
187
188/**
189 * drm_encoder_index - find the index of a registered encoder
190 * @encoder: encoder to find index for
191 *
192 * Given a registered encoder, return the index of that encoder within a DRM
193 * device's list of encoders.
194 */
195static inline unsigned int drm_encoder_index(const struct drm_encoder *encoder)
196{
197	return encoder->index;
198}
199
200/**
201 * drm_encoder_mask - find the mask of a registered ENCODER
202 * @encoder: encoder to find mask for
203 *
204 * Given a registered encoder, return the mask bit of that encoder for an
205 * encoder's possible_clones field.
206 */
207static inline u32 drm_encoder_mask(const struct drm_encoder *encoder)
208{
209	return 1 << drm_encoder_index(encoder);
210}
211
212/**
213 * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
214 * @encoder: encoder to test
215 * @crtc: crtc to test
216 *
217 * Returns false if @encoder can't be driven by @crtc, true otherwise.
218 */
219static inline bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
220				       struct drm_crtc *crtc)
221{
222	return !!(encoder->possible_crtcs & drm_crtc_mask(crtc));
223}
224
225/**
226 * drm_encoder_find - find a &drm_encoder
227 * @dev: DRM device
228 * @file_priv: drm file to check for lease against.
229 * @id: encoder id
230 *
231 * Returns the encoder with @id, NULL if it doesn't exist. Simple wrapper around
232 * drm_mode_object_find().
233 */
234static inline struct drm_encoder *drm_encoder_find(struct drm_device *dev,
235						   struct drm_file *file_priv,
236						   uint32_t id)
237{
238	struct drm_mode_object *mo;
239
240	mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_ENCODER);
241
242	return mo ? obj_to_encoder(mo) : NULL;
243}
244
245void drm_encoder_cleanup(struct drm_encoder *encoder);
246
247/**
248 * drm_for_each_encoder_mask - iterate over encoders specified by bitmask
249 * @encoder: the loop cursor
250 * @dev: the DRM device
251 * @encoder_mask: bitmask of encoder indices
252 *
253 * Iterate over all encoders specified by bitmask.
254 */
255#define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
256	list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
257		for_each_if ((encoder_mask) & drm_encoder_mask(encoder))
258
259/**
260 * drm_for_each_encoder - iterate over all encoders
261 * @encoder: the loop cursor
262 * @dev: the DRM device
263 *
264 * Iterate over all encoders of @dev.
265 */
266#define drm_for_each_encoder(encoder, dev) \
267	list_for_each_entry(encoder, &(dev)->mode_config.encoder_list, head)
268
269#endif