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_CONNECTOR_H__
24 #define __DRM_CONNECTOR_H__
25 
26 #include <linux/list.h>
27 #include <linux/llist.h>
28 #include <linux/ctype.h>
29 #include <linux/hdmi.h>
30 #include <drm/drm_mode_object.h>
31 
32 #include <uapi/drm/drm_mode.h>
33 
34 struct drm_connector_helper_funcs;
35 struct drm_modeset_acquire_ctx;
36 struct drm_device;
37 struct drm_crtc;
38 struct drm_encoder;
39 struct drm_property;
40 struct drm_property_blob;
41 struct drm_printer;
42 struct edid;
43 
44 enum drm_connector_force {
45 	DRM_FORCE_UNSPECIFIED,
46 	DRM_FORCE_OFF,
47 	DRM_FORCE_ON,         /* force on analog part normally */
48 	DRM_FORCE_ON_DIGITAL, /* for DVI-I use digital connector */
49 };
50 
51 /**
52  * enum drm_connector_status - status for a &drm_connector
53  *
54  * This enum is used to track the connector status. There are no separate
55  * #defines for the uapi!
56  */
57 enum drm_connector_status {
58 	/**
59 	 * @connector_status_connected: The connector is definitely connected to
60 	 * a sink device, and can be enabled.
61 	 */
62 	connector_status_connected = 1,
63 	/**
64 	 * @connector_status_disconnected: The connector isn't connected to a
65 	 * sink device which can be autodetect. For digital outputs like DP or
66 	 * HDMI (which can be realiable probed) this means there's really
67 	 * nothing there. It is driver-dependent whether a connector with this
68 	 * status can be lit up or not.
69 	 */
70 	connector_status_disconnected = 2,
71 	/**
72 	 * @connector_status_unknown: The connector's status could not be
73 	 * reliably detected. This happens when probing would either cause
74 	 * flicker (like load-detection when the connector is in use), or when a
75 	 * hardware resource isn't available (like when load-detection needs a
76 	 * free CRTC). It should be possible to light up the connector with one
77 	 * of the listed fallback modes. For default configuration userspace
78 	 * should only try to light up connectors with unknown status when
79 	 * there's not connector with @connector_status_connected.
80 	 */
81 	connector_status_unknown = 3,
82 };
83 
84 enum subpixel_order {
85 	SubPixelUnknown = 0,
86 	SubPixelHorizontalRGB,
87 	SubPixelHorizontalBGR,
88 	SubPixelVerticalRGB,
89 	SubPixelVerticalBGR,
90 	SubPixelNone,
91 
92 };
93 
94 /**
95  * struct drm_scrambling: sink's scrambling support.
96  */
97 struct drm_scrambling {
98 	/**
99 	 * @supported: scrambling supported for rates > 340 Mhz.
100 	 */
101 	bool supported;
102 	/**
103 	 * @low_rates: scrambling supported for rates <= 340 Mhz.
104 	 */
105 	bool low_rates;
106 };
107 
108 /*
109  * struct drm_scdc - Information about scdc capabilities of a HDMI 2.0 sink
110  *
111  * Provides SCDC register support and capabilities related information on a
112  * HDMI 2.0 sink. In case of a HDMI 1.4 sink, all parameter must be 0.
113  */
114 struct drm_scdc {
115 	/**
116 	 * @supported: status control & data channel present.
117 	 */
118 	bool supported;
119 	/**
120 	 * @read_request: sink is capable of generating scdc read request.
121 	 */
122 	bool read_request;
123 	/**
124 	 * @scrambling: sink's scrambling capabilities
125 	 */
126 	struct drm_scrambling scrambling;
127 };
128 
129 
130 /**
131  * struct drm_hdmi_info - runtime information about the connected HDMI sink
132  *
133  * Describes if a given display supports advanced HDMI 2.0 features.
134  * This information is available in CEA-861-F extension blocks (like HF-VSDB).
135  */
136 struct drm_hdmi_info {
137 	/** @scdc: sink's scdc support and capabilities */
138 	struct drm_scdc scdc;
139 
140 	/**
141 	 * @y420_vdb_modes: bitmap of modes which can support ycbcr420
142 	 * output only (not normal RGB/YCBCR444/422 outputs). There are total
143 	 * 107 VICs defined by CEA-861-F spec, so the size is 128 bits to map
144 	 * upto 128 VICs;
145 	 */
146 	unsigned long y420_vdb_modes[BITS_TO_LONGS(128)];
147 
148 	/**
149 	 * @y420_cmdb_modes: bitmap of modes which can support ycbcr420
150 	 * output also, along with normal HDMI outputs. There are total 107
151 	 * VICs defined by CEA-861-F spec, so the size is 128 bits to map upto
152 	 * 128 VICs;
153 	 */
154 	unsigned long y420_cmdb_modes[BITS_TO_LONGS(128)];
155 
156 	/** @y420_cmdb_map: bitmap of SVD index, to extraxt vcb modes */
157 	u64 y420_cmdb_map;
158 
159 	/** @y420_dc_modes: bitmap of deep color support index */
160 	u8 y420_dc_modes;
161 };
162 
163 /**
164  * enum drm_link_status - connector's link_status property value
165  *
166  * This enum is used as the connector's link status property value.
167  * It is set to the values defined in uapi.
168  *
169  * @DRM_LINK_STATUS_GOOD: DP Link is Good as a result of successful
170  *                        link training
171  * @DRM_LINK_STATUS_BAD: DP Link is BAD as a result of link training
172  *                       failure
173  */
174 enum drm_link_status {
175 	DRM_LINK_STATUS_GOOD = DRM_MODE_LINK_STATUS_GOOD,
176 	DRM_LINK_STATUS_BAD = DRM_MODE_LINK_STATUS_BAD,
177 };
178 
179 /**
180  * enum drm_panel_orientation - panel_orientation info for &drm_display_info
181  *
182  * This enum is used to track the (LCD) panel orientation. There are no
183  * separate #defines for the uapi!
184  *
185  * @DRM_MODE_PANEL_ORIENTATION_UNKNOWN: The drm driver has not provided any
186  *					panel orientation information (normal
187  *					for non panels) in this case the "panel
188  *					orientation" connector prop will not be
189  *					attached.
190  * @DRM_MODE_PANEL_ORIENTATION_NORMAL:	The top side of the panel matches the
191  *					top side of the device's casing.
192  * @DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP: The top side of the panel matches the
193  *					bottom side of the device's casing, iow
194  *					the panel is mounted upside-down.
195  * @DRM_MODE_PANEL_ORIENTATION_LEFT_UP:	The left side of the panel matches the
196  *					top side of the device's casing.
197  * @DRM_MODE_PANEL_ORIENTATION_RIGHT_UP: The right side of the panel matches the
198  *					top side of the device's casing.
199  */
200 enum drm_panel_orientation {
201 	DRM_MODE_PANEL_ORIENTATION_UNKNOWN = -1,
202 	DRM_MODE_PANEL_ORIENTATION_NORMAL = 0,
203 	DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP,
204 	DRM_MODE_PANEL_ORIENTATION_LEFT_UP,
205 	DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,
206 };
207 
208 /**
209  * struct drm_display_info - runtime data about the connected sink
210  *
211  * Describes a given display (e.g. CRT or flat panel) and its limitations. For
212  * fixed display sinks like built-in panels there's not much difference between
213  * this and &struct drm_connector. But for sinks with a real cable this
214  * structure is meant to describe all the things at the other end of the cable.
215  *
216  * For sinks which provide an EDID this can be filled out by calling
217  * drm_add_edid_modes().
218  */
219 struct drm_display_info {
220 	/**
221 	 * @name: Name of the display.
222 	 */
223 	char name[DRM_DISPLAY_INFO_LEN];
224 
225 	/**
226 	 * @width_mm: Physical width in mm.
227 	 */
228         unsigned int width_mm;
229 	/**
230 	 * @height_mm: Physical height in mm.
231 	 */
232 	unsigned int height_mm;
233 
234 	/**
235 	 * @pixel_clock: Maximum pixel clock supported by the sink, in units of
236 	 * 100Hz. This mismatches the clock in &drm_display_mode (which is in
237 	 * kHZ), because that's what the EDID uses as base unit.
238 	 */
239 	unsigned int pixel_clock;
240 	/**
241 	 * @bpc: Maximum bits per color channel. Used by HDMI and DP outputs.
242 	 */
243 	unsigned int bpc;
244 
245 	/**
246 	 * @subpixel_order: Subpixel order of LCD panels.
247 	 */
248 	enum subpixel_order subpixel_order;
249 
250 #define DRM_COLOR_FORMAT_RGB444		(1<<0)
251 #define DRM_COLOR_FORMAT_YCRCB444	(1<<1)
252 #define DRM_COLOR_FORMAT_YCRCB422	(1<<2)
253 #define DRM_COLOR_FORMAT_YCRCB420	(1<<3)
254 
255 	/**
256 	 * @panel_orientation: Read only connector property for built-in panels,
257 	 * indicating the orientation of the panel vs the device's casing.
258 	 * drm_connector_init() sets this to DRM_MODE_PANEL_ORIENTATION_UNKNOWN.
259 	 * When not UNKNOWN this gets used by the drm_fb_helpers to rotate the
260 	 * fb to compensate and gets exported as prop to userspace.
261 	 */
262 	int panel_orientation;
263 
264 	/**
265 	 * @color_formats: HDMI Color formats, selects between RGB and YCrCb
266 	 * modes. Used DRM_COLOR_FORMAT\_ defines, which are _not_ the same ones
267 	 * as used to describe the pixel format in framebuffers, and also don't
268 	 * match the formats in @bus_formats which are shared with v4l.
269 	 */
270 	u32 color_formats;
271 
272 	/**
273 	 * @bus_formats: Pixel data format on the wire, somewhat redundant with
274 	 * @color_formats. Array of size @num_bus_formats encoded using
275 	 * MEDIA_BUS_FMT\_ defines shared with v4l and media drivers.
276 	 */
277 	const u32 *bus_formats;
278 	/**
279 	 * @num_bus_formats: Size of @bus_formats array.
280 	 */
281 	unsigned int num_bus_formats;
282 
283 #define DRM_BUS_FLAG_DE_LOW		(1<<0)
284 #define DRM_BUS_FLAG_DE_HIGH		(1<<1)
285 /* drive data on pos. edge */
286 #define DRM_BUS_FLAG_PIXDATA_POSEDGE	(1<<2)
287 /* drive data on neg. edge */
288 #define DRM_BUS_FLAG_PIXDATA_NEGEDGE	(1<<3)
289 /* data is transmitted MSB to LSB on the bus */
290 #define DRM_BUS_FLAG_DATA_MSB_TO_LSB	(1<<4)
291 /* data is transmitted LSB to MSB on the bus */
292 #define DRM_BUS_FLAG_DATA_LSB_TO_MSB	(1<<5)
293 /* drive sync on pos. edge */
294 #define DRM_BUS_FLAG_SYNC_POSEDGE	(1<<6)
295 /* drive sync on neg. edge */
296 #define DRM_BUS_FLAG_SYNC_NEGEDGE	(1<<7)
297 
298 	/**
299 	 * @bus_flags: Additional information (like pixel signal polarity) for
300 	 * the pixel data on the bus, using DRM_BUS_FLAGS\_ defines.
301 	 */
302 	u32 bus_flags;
303 
304 	/**
305 	 * @max_tmds_clock: Maximum TMDS clock rate supported by the
306 	 * sink in kHz. 0 means undefined.
307 	 */
308 	int max_tmds_clock;
309 
310 	/**
311 	 * @dvi_dual: Dual-link DVI sink?
312 	 */
313 	bool dvi_dual;
314 
315 	/**
316 	 * @has_hdmi_infoframe: Does the sink support the HDMI infoframe?
317 	 */
318 	bool has_hdmi_infoframe;
319 
320 	/**
321 	 * @edid_hdmi_dc_modes: Mask of supported hdmi deep color modes. Even
322 	 * more stuff redundant with @bus_formats.
323 	 */
324 	u8 edid_hdmi_dc_modes;
325 
326 	/**
327 	 * @cea_rev: CEA revision of the HDMI sink.
328 	 */
329 	u8 cea_rev;
330 
331 	/**
332 	 * @hdmi: advance features of a HDMI sink.
333 	 */
334 	struct drm_hdmi_info hdmi;
335 
336 	/**
337 	 * @non_desktop: Non desktop display (HMD).
338 	 */
339 	bool non_desktop;
340 };
341 
342 int drm_display_info_set_bus_formats(struct drm_display_info *info,
343 				     const u32 *formats,
344 				     unsigned int num_formats);
345 
346 /**
347  * struct drm_tv_connector_state - TV connector related states
348  * @subconnector: selected subconnector
349  * @margins: margins
350  * @margins.left: left margin
351  * @margins.right: right margin
352  * @margins.top: top margin
353  * @margins.bottom: bottom margin
354  * @mode: TV mode
355  * @brightness: brightness in percent
356  * @contrast: contrast in percent
357  * @flicker_reduction: flicker reduction in percent
358  * @overscan: overscan in percent
359  * @saturation: saturation in percent
360  * @hue: hue in percent
361  */
362 struct drm_tv_connector_state {
363 	enum drm_mode_subconnector subconnector;
364 	struct {
365 		unsigned int left;
366 		unsigned int right;
367 		unsigned int top;
368 		unsigned int bottom;
369 	} margins;
370 	unsigned int mode;
371 	unsigned int brightness;
372 	unsigned int contrast;
373 	unsigned int flicker_reduction;
374 	unsigned int overscan;
375 	unsigned int saturation;
376 	unsigned int hue;
377 };
378 
379 /**
380  * struct drm_connector_state - mutable connector state
381  */
382 struct drm_connector_state {
383 	/** @connector: backpointer to the connector */
384 	struct drm_connector *connector;
385 
386 	/**
387 	 * @crtc: CRTC to connect connector to, NULL if disabled.
388 	 *
389 	 * Do not change this directly, use drm_atomic_set_crtc_for_connector()
390 	 * instead.
391 	 */
392 	struct drm_crtc *crtc;
393 
394 	/**
395 	 * @best_encoder:
396 	 *
397 	 * Used by the atomic helpers to select the encoder, through the
398 	 * &drm_connector_helper_funcs.atomic_best_encoder or
399 	 * &drm_connector_helper_funcs.best_encoder callbacks.
400 	 */
401 	struct drm_encoder *best_encoder;
402 
403 	/**
404 	 * @link_status: Connector link_status to keep track of whether link is
405 	 * GOOD or BAD to notify userspace if retraining is necessary.
406 	 */
407 	enum drm_link_status link_status;
408 
409 	/** @state: backpointer to global drm_atomic_state */
410 	struct drm_atomic_state *state;
411 
412 	/**
413 	 * @commit: Tracks the pending commit to prevent use-after-free conditions.
414 	 *
415 	 * Is only set when @crtc is NULL.
416 	 */
417 	struct drm_crtc_commit *commit;
418 
419 	/** @tv: TV connector state */
420 	struct drm_tv_connector_state tv;
421 
422 	/**
423 	 * @picture_aspect_ratio: Connector property to control the
424 	 * HDMI infoframe aspect ratio setting.
425 	 *
426 	 * The %DRM_MODE_PICTURE_ASPECT_\* values much match the
427 	 * values for &enum hdmi_picture_aspect
428 	 */
429 	enum hdmi_picture_aspect picture_aspect_ratio;
430 
431 	/**
432 	 * @content_type: Connector property to control the
433 	 * HDMI infoframe content type setting.
434 	 * The %DRM_MODE_CONTENT_TYPE_\* values much
435 	 * match the values.
436 	 */
437 	unsigned int content_type;
438 
439 	/**
440 	 * @scaling_mode: Connector property to control the
441 	 * upscaling, mostly used for built-in panels.
442 	 */
443 	unsigned int scaling_mode;
444 
445 	/**
446 	 * @content_protection: Connector property to request content
447 	 * protection. This is most commonly used for HDCP.
448 	 */
449 	unsigned int content_protection;
450 
451 	/**
452 	 * @writeback_job: Writeback job for writeback connectors
453 	 *
454 	 * Holds the framebuffer and out-fence for a writeback connector. As
455 	 * the writeback completion may be asynchronous to the normal commit
456 	 * cycle, the writeback job lifetime is managed separately from the
457 	 * normal atomic state by this object.
458 	 *
459 	 * See also: drm_writeback_queue_job() and
460 	 * drm_writeback_signal_completion()
461 	 */
462 	struct drm_writeback_job *writeback_job;
463 };
464 
465 /**
466  * struct drm_connector_funcs - control connectors on a given device
467  *
468  * Each CRTC may have one or more connectors attached to it.  The functions
469  * below allow the core DRM code to control connectors, enumerate available modes,
470  * etc.
471  */
472 struct drm_connector_funcs {
473 	/**
474 	 * @dpms:
475 	 *
476 	 * Legacy entry point to set the per-connector DPMS state. Legacy DPMS
477 	 * is exposed as a standard property on the connector, but diverted to
478 	 * this callback in the drm core. Note that atomic drivers don't
479 	 * implement the 4 level DPMS support on the connector any more, but
480 	 * instead only have an on/off "ACTIVE" property on the CRTC object.
481 	 *
482 	 * This hook is not used by atomic drivers, remapping of the legacy DPMS
483 	 * property is entirely handled in the DRM core.
484 	 *
485 	 * RETURNS:
486 	 *
487 	 * 0 on success or a negative error code on failure.
488 	 */
489 	int (*dpms)(struct drm_connector *connector, int mode);
490 
491 	/**
492 	 * @reset:
493 	 *
494 	 * Reset connector hardware and software state to off. This function isn't
495 	 * called by the core directly, only through drm_mode_config_reset().
496 	 * It's not a helper hook only for historical reasons.
497 	 *
498 	 * Atomic drivers can use drm_atomic_helper_connector_reset() to reset
499 	 * atomic state using this hook.
500 	 */
501 	void (*reset)(struct drm_connector *connector);
502 
503 	/**
504 	 * @detect:
505 	 *
506 	 * Check to see if anything is attached to the connector. The parameter
507 	 * force is set to false whilst polling, true when checking the
508 	 * connector due to a user request. force can be used by the driver to
509 	 * avoid expensive, destructive operations during automated probing.
510 	 *
511 	 * This callback is optional, if not implemented the connector will be
512 	 * considered as always being attached.
513 	 *
514 	 * FIXME:
515 	 *
516 	 * Note that this hook is only called by the probe helper. It's not in
517 	 * the helper library vtable purely for historical reasons. The only DRM
518 	 * core	entry point to probe connector state is @fill_modes.
519 	 *
520 	 * Note that the helper library will already hold
521 	 * &drm_mode_config.connection_mutex. Drivers which need to grab additional
522 	 * locks to avoid races with concurrent modeset changes need to use
523 	 * &drm_connector_helper_funcs.detect_ctx instead.
524 	 *
525 	 * RETURNS:
526 	 *
527 	 * drm_connector_status indicating the connector's status.
528 	 */
529 	enum drm_connector_status (*detect)(struct drm_connector *connector,
530 					    bool force);
531 
532 	/**
533 	 * @force:
534 	 *
535 	 * This function is called to update internal encoder state when the
536 	 * connector is forced to a certain state by userspace, either through
537 	 * the sysfs interfaces or on the kernel cmdline. In that case the
538 	 * @detect callback isn't called.
539 	 *
540 	 * FIXME:
541 	 *
542 	 * Note that this hook is only called by the probe helper. It's not in
543 	 * the helper library vtable purely for historical reasons. The only DRM
544 	 * core	entry point to probe connector state is @fill_modes.
545 	 */
546 	void (*force)(struct drm_connector *connector);
547 
548 	/**
549 	 * @fill_modes:
550 	 *
551 	 * Entry point for output detection and basic mode validation. The
552 	 * driver should reprobe the output if needed (e.g. when hotplug
553 	 * handling is unreliable), add all detected modes to &drm_connector.modes
554 	 * and filter out any the device can't support in any configuration. It
555 	 * also needs to filter out any modes wider or higher than the
556 	 * parameters max_width and max_height indicate.
557 	 *
558 	 * The drivers must also prune any modes no longer valid from
559 	 * &drm_connector.modes. Furthermore it must update
560 	 * &drm_connector.status and &drm_connector.edid.  If no EDID has been
561 	 * received for this output connector->edid must be NULL.
562 	 *
563 	 * Drivers using the probe helpers should use
564 	 * drm_helper_probe_single_connector_modes() to implement this
565 	 * function.
566 	 *
567 	 * RETURNS:
568 	 *
569 	 * The number of modes detected and filled into &drm_connector.modes.
570 	 */
571 	int (*fill_modes)(struct drm_connector *connector, uint32_t max_width, uint32_t max_height);
572 
573 	/**
574 	 * @set_property:
575 	 *
576 	 * This is the legacy entry point to update a property attached to the
577 	 * connector.
578 	 *
579 	 * This callback is optional if the driver does not support any legacy
580 	 * driver-private properties. For atomic drivers it is not used because
581 	 * property handling is done entirely in the DRM core.
582 	 *
583 	 * RETURNS:
584 	 *
585 	 * 0 on success or a negative error code on failure.
586 	 */
587 	int (*set_property)(struct drm_connector *connector, struct drm_property *property,
588 			     uint64_t val);
589 
590 	/**
591 	 * @late_register:
592 	 *
593 	 * This optional hook can be used to register additional userspace
594 	 * interfaces attached to the connector, light backlight control, i2c,
595 	 * DP aux or similar interfaces. It is called late in the driver load
596 	 * sequence from drm_connector_register() when registering all the
597 	 * core drm connector interfaces. Everything added from this callback
598 	 * should be unregistered in the early_unregister callback.
599 	 *
600 	 * This is called while holding &drm_connector.mutex.
601 	 *
602 	 * Returns:
603 	 *
604 	 * 0 on success, or a negative error code on failure.
605 	 */
606 	int (*late_register)(struct drm_connector *connector);
607 
608 	/**
609 	 * @early_unregister:
610 	 *
611 	 * This optional hook should be used to unregister the additional
612 	 * userspace interfaces attached to the connector from
613 	 * late_register(). It is called from drm_connector_unregister(),
614 	 * early in the driver unload sequence to disable userspace access
615 	 * before data structures are torndown.
616 	 *
617 	 * This is called while holding &drm_connector.mutex.
618 	 */
619 	void (*early_unregister)(struct drm_connector *connector);
620 
621 	/**
622 	 * @destroy:
623 	 *
624 	 * Clean up connector resources. This is called at driver unload time
625 	 * through drm_mode_config_cleanup(). It can also be called at runtime
626 	 * when a connector is being hot-unplugged for drivers that support
627 	 * connector hotplugging (e.g. DisplayPort MST).
628 	 */
629 	void (*destroy)(struct drm_connector *connector);
630 
631 	/**
632 	 * @atomic_duplicate_state:
633 	 *
634 	 * Duplicate the current atomic state for this connector and return it.
635 	 * The core and helpers guarantee that any atomic state duplicated with
636 	 * this hook and still owned by the caller (i.e. not transferred to the
637 	 * driver by calling &drm_mode_config_funcs.atomic_commit) will be
638 	 * cleaned up by calling the @atomic_destroy_state hook in this
639 	 * structure.
640 	 *
641 	 * This callback is mandatory for atomic drivers.
642 	 *
643 	 * Atomic drivers which don't subclass &struct drm_connector_state should use
644 	 * drm_atomic_helper_connector_duplicate_state(). Drivers that subclass the
645 	 * state structure to extend it with driver-private state should use
646 	 * __drm_atomic_helper_connector_duplicate_state() to make sure shared state is
647 	 * duplicated in a consistent fashion across drivers.
648 	 *
649 	 * It is an error to call this hook before &drm_connector.state has been
650 	 * initialized correctly.
651 	 *
652 	 * NOTE:
653 	 *
654 	 * If the duplicate state references refcounted resources this hook must
655 	 * acquire a reference for each of them. The driver must release these
656 	 * references again in @atomic_destroy_state.
657 	 *
658 	 * RETURNS:
659 	 *
660 	 * Duplicated atomic state or NULL when the allocation failed.
661 	 */
662 	struct drm_connector_state *(*atomic_duplicate_state)(struct drm_connector *connector);
663 
664 	/**
665 	 * @atomic_destroy_state:
666 	 *
667 	 * Destroy a state duplicated with @atomic_duplicate_state and release
668 	 * or unreference all resources it references
669 	 *
670 	 * This callback is mandatory for atomic drivers.
671 	 */
672 	void (*atomic_destroy_state)(struct drm_connector *connector,
673 				     struct drm_connector_state *state);
674 
675 	/**
676 	 * @atomic_set_property:
677 	 *
678 	 * Decode a driver-private property value and store the decoded value
679 	 * into the passed-in state structure. Since the atomic core decodes all
680 	 * standardized properties (even for extensions beyond the core set of
681 	 * properties which might not be implemented by all drivers) this
682 	 * requires drivers to subclass the state structure.
683 	 *
684 	 * Such driver-private properties should really only be implemented for
685 	 * truly hardware/vendor specific state. Instead it is preferred to
686 	 * standardize atomic extension and decode the properties used to expose
687 	 * such an extension in the core.
688 	 *
689 	 * Do not call this function directly, use
690 	 * drm_atomic_connector_set_property() instead.
691 	 *
692 	 * This callback is optional if the driver does not support any
693 	 * driver-private atomic properties.
694 	 *
695 	 * NOTE:
696 	 *
697 	 * This function is called in the state assembly phase of atomic
698 	 * modesets, which can be aborted for any reason (including on
699 	 * userspace's request to just check whether a configuration would be
700 	 * possible). Drivers MUST NOT touch any persistent state (hardware or
701 	 * software) or data structures except the passed in @state parameter.
702 	 *
703 	 * Also since userspace controls in which order properties are set this
704 	 * function must not do any input validation (since the state update is
705 	 * incomplete and hence likely inconsistent). Instead any such input
706 	 * validation must be done in the various atomic_check callbacks.
707 	 *
708 	 * RETURNS:
709 	 *
710 	 * 0 if the property has been found, -EINVAL if the property isn't
711 	 * implemented by the driver (which shouldn't ever happen, the core only
712 	 * asks for properties attached to this connector). No other validation
713 	 * is allowed by the driver. The core already checks that the property
714 	 * value is within the range (integer, valid enum value, ...) the driver
715 	 * set when registering the property.
716 	 */
717 	int (*atomic_set_property)(struct drm_connector *connector,
718 				   struct drm_connector_state *state,
719 				   struct drm_property *property,
720 				   uint64_t val);
721 
722 	/**
723 	 * @atomic_get_property:
724 	 *
725 	 * Reads out the decoded driver-private property. This is used to
726 	 * implement the GETCONNECTOR IOCTL.
727 	 *
728 	 * Do not call this function directly, use
729 	 * drm_atomic_connector_get_property() instead.
730 	 *
731 	 * This callback is optional if the driver does not support any
732 	 * driver-private atomic properties.
733 	 *
734 	 * RETURNS:
735 	 *
736 	 * 0 on success, -EINVAL if the property isn't implemented by the
737 	 * driver (which shouldn't ever happen, the core only asks for
738 	 * properties attached to this connector).
739 	 */
740 	int (*atomic_get_property)(struct drm_connector *connector,
741 				   const struct drm_connector_state *state,
742 				   struct drm_property *property,
743 				   uint64_t *val);
744 
745 	/**
746 	 * @atomic_print_state:
747 	 *
748 	 * If driver subclasses &struct drm_connector_state, it should implement
749 	 * this optional hook for printing additional driver specific state.
750 	 *
751 	 * Do not call this directly, use drm_atomic_connector_print_state()
752 	 * instead.
753 	 */
754 	void (*atomic_print_state)(struct drm_printer *p,
755 				   const struct drm_connector_state *state);
756 };
757 
758 /* mode specified on the command line */
759 struct drm_cmdline_mode {
760 	bool specified;
761 	bool refresh_specified;
762 	bool bpp_specified;
763 	int xres, yres;
764 	int bpp;
765 	int refresh;
766 	bool rb;
767 	bool interlace;
768 	bool cvt;
769 	bool margins;
770 	enum drm_connector_force force;
771 };
772 
773 /**
774  * struct drm_connector - central DRM connector control structure
775  *
776  * Each connector may be connected to one or more CRTCs, or may be clonable by
777  * another connector if they can share a CRTC.  Each connector also has a specific
778  * position in the broader display (referred to as a 'screen' though it could
779  * span multiple monitors).
780  */
781 struct drm_connector {
782 	/** @dev: parent DRM device */
783 	struct drm_device *dev;
784 	/** @kdev: kernel device for sysfs attributes */
785 	struct device *kdev;
786 	/** @attr: sysfs attributes */
787 	struct device_attribute *attr;
788 
789 	/**
790 	 * @head:
791 	 *
792 	 * List of all connectors on a @dev, linked from
793 	 * &drm_mode_config.connector_list. Protected by
794 	 * &drm_mode_config.connector_list_lock, but please only use
795 	 * &drm_connector_list_iter to walk this list.
796 	 */
797 	struct list_head head;
798 
799 	/** @base: base KMS object */
800 	struct drm_mode_object base;
801 
802 	/** @name: human readable name, can be overwritten by the driver */
803 	char *name;
804 
805 	/**
806 	 * @mutex: Lock for general connector state, but currently only protects
807 	 * @registered. Most of the connector state is still protected by
808 	 * &drm_mode_config.mutex.
809 	 */
810 	struct mutex mutex;
811 
812 	/**
813 	 * @index: Compacted connector index, which matches the position inside
814 	 * the mode_config.list for drivers not supporting hot-add/removing. Can
815 	 * be used as an array index. It is invariant over the lifetime of the
816 	 * connector.
817 	 */
818 	unsigned index;
819 
820 	/**
821 	 * @connector_type:
822 	 * one of the DRM_MODE_CONNECTOR_<foo> types from drm_mode.h
823 	 */
824 	int connector_type;
825 	/** @connector_type_id: index into connector type enum */
826 	int connector_type_id;
827 	/**
828 	 * @interlace_allowed:
829 	 * Can this connector handle interlaced modes? Only used by
830 	 * drm_helper_probe_single_connector_modes() for mode filtering.
831 	 */
832 	bool interlace_allowed;
833 	/**
834 	 * @doublescan_allowed:
835 	 * Can this connector handle doublescan? Only used by
836 	 * drm_helper_probe_single_connector_modes() for mode filtering.
837 	 */
838 	bool doublescan_allowed;
839 	/**
840 	 * @stereo_allowed:
841 	 * Can this connector handle stereo modes? Only used by
842 	 * drm_helper_probe_single_connector_modes() for mode filtering.
843 	 */
844 	bool stereo_allowed;
845 
846 	/**
847 	 * @ycbcr_420_allowed : This bool indicates if this connector is
848 	 * capable of handling YCBCR 420 output. While parsing the EDID
849 	 * blocks, its very helpful to know, if the source is capable of
850 	 * handling YCBCR 420 outputs.
851 	 */
852 	bool ycbcr_420_allowed;
853 
854 	/**
855 	 * @registered: Is this connector exposed (registered) with userspace?
856 	 * Protected by @mutex.
857 	 */
858 	bool registered;
859 
860 	/**
861 	 * @modes:
862 	 * Modes available on this connector (from fill_modes() + user).
863 	 * Protected by &drm_mode_config.mutex.
864 	 */
865 	struct list_head modes;
866 
867 	/**
868 	 * @status:
869 	 * One of the drm_connector_status enums (connected, not, or unknown).
870 	 * Protected by &drm_mode_config.mutex.
871 	 */
872 	enum drm_connector_status status;
873 
874 	/**
875 	 * @probed_modes:
876 	 * These are modes added by probing with DDC or the BIOS, before
877 	 * filtering is applied. Used by the probe helpers. Protected by
878 	 * &drm_mode_config.mutex.
879 	 */
880 	struct list_head probed_modes;
881 
882 	/**
883 	 * @display_info: Display information is filled from EDID information
884 	 * when a display is detected. For non hot-pluggable displays such as
885 	 * flat panels in embedded systems, the driver should initialize the
886 	 * &drm_display_info.width_mm and &drm_display_info.height_mm fields
887 	 * with the physical size of the display.
888 	 *
889 	 * Protected by &drm_mode_config.mutex.
890 	 */
891 	struct drm_display_info display_info;
892 
893 	/** @funcs: connector control functions */
894 	const struct drm_connector_funcs *funcs;
895 
896 	/**
897 	 * @edid_blob_ptr: DRM property containing EDID if present. Protected by
898 	 * &drm_mode_config.mutex. This should be updated only by calling
899 	 * drm_connector_update_edid_property().
900 	 */
901 	struct drm_property_blob *edid_blob_ptr;
902 
903 	/** @properties: property tracking for this connector */
904 	struct drm_object_properties properties;
905 
906 	/**
907 	 * @scaling_mode_property: Optional atomic property to control the
908 	 * upscaling. See drm_connector_attach_content_protection_property().
909 	 */
910 	struct drm_property *scaling_mode_property;
911 
912 	/**
913 	 * @content_protection_property: DRM ENUM property for content
914 	 * protection. See drm_connector_attach_content_protection_property().
915 	 */
916 	struct drm_property *content_protection_property;
917 
918 	/**
919 	 * @path_blob_ptr:
920 	 *
921 	 * DRM blob property data for the DP MST path property. This should only
922 	 * be updated by calling drm_connector_set_path_property().
923 	 */
924 	struct drm_property_blob *path_blob_ptr;
925 
926 #define DRM_CONNECTOR_POLL_HPD (1 << 0)
927 #define DRM_CONNECTOR_POLL_CONNECT (1 << 1)
928 #define DRM_CONNECTOR_POLL_DISCONNECT (1 << 2)
929 
930 	/**
931 	 * @polled:
932 	 *
933 	 * Connector polling mode, a combination of
934 	 *
935 	 * DRM_CONNECTOR_POLL_HPD
936 	 *     The connector generates hotplug events and doesn't need to be
937 	 *     periodically polled. The CONNECT and DISCONNECT flags must not
938 	 *     be set together with the HPD flag.
939 	 *
940 	 * DRM_CONNECTOR_POLL_CONNECT
941 	 *     Periodically poll the connector for connection.
942 	 *
943 	 * DRM_CONNECTOR_POLL_DISCONNECT
944 	 *     Periodically poll the connector for disconnection, without
945 	 *     causing flickering even when the connector is in use. DACs should
946 	 *     rarely do this without a lot of testing.
947 	 *
948 	 * Set to 0 for connectors that don't support connection status
949 	 * discovery.
950 	 */
951 	uint8_t polled;
952 
953 	/**
954 	 * @dpms: Current dpms state. For legacy drivers the
955 	 * &drm_connector_funcs.dpms callback must update this. For atomic
956 	 * drivers, this is handled by the core atomic code, and drivers must
957 	 * only take &drm_crtc_state.active into account.
958 	 */
959 	int dpms;
960 
961 	/** @helper_private: mid-layer private data */
962 	const struct drm_connector_helper_funcs *helper_private;
963 
964 	/** @cmdline_mode: mode line parsed from the kernel cmdline for this connector */
965 	struct drm_cmdline_mode cmdline_mode;
966 	/** @force: a DRM_FORCE_<foo> state for forced mode sets */
967 	enum drm_connector_force force;
968 	/** @override_edid: has the EDID been overwritten through debugfs for testing? */
969 	bool override_edid;
970 
971 #define DRM_CONNECTOR_MAX_ENCODER 3
972 	/**
973 	 * @encoder_ids: Valid encoders for this connector. Please only use
974 	 * drm_connector_for_each_possible_encoder() to enumerate these.
975 	 */
976 	uint32_t encoder_ids[DRM_CONNECTOR_MAX_ENCODER];
977 
978 	/**
979 	 * @encoder: Currently bound encoder driving this connector, if any.
980 	 * Only really meaningful for non-atomic drivers. Atomic drivers should
981 	 * instead look at &drm_connector_state.best_encoder, and in case they
982 	 * need the CRTC driving this output, &drm_connector_state.crtc.
983 	 */
984 	struct drm_encoder *encoder;
985 
986 #define MAX_ELD_BYTES	128
987 	/** @eld: EDID-like data, if present */
988 	uint8_t eld[MAX_ELD_BYTES];
989 	/** @latency_present: AV delay info from ELD, if found */
990 	bool latency_present[2];
991 	/**
992 	 * @video_latency: Video latency info from ELD, if found.
993 	 * [0]: progressive, [1]: interlaced
994 	 */
995 	int video_latency[2];
996 	/**
997 	 * @audio_latency: audio latency info from ELD, if found
998 	 * [0]: progressive, [1]: interlaced
999 	 */
1000 	int audio_latency[2];
1001 	/**
1002 	 * @null_edid_counter: track sinks that give us all zeros for the EDID.
1003 	 * Needed to workaround some HW bugs where we get all 0s
1004 	 */
1005 	int null_edid_counter;
1006 
1007 	/** @bad_edid_counter: track sinks that give us an EDID with invalid checksum */
1008 	unsigned bad_edid_counter;
1009 
1010 	/**
1011 	 * @edid_corrupt: Indicates whether the last read EDID was corrupt. Used
1012 	 * in Displayport compliance testing - Displayport Link CTS Core 1.2
1013 	 * rev1.1 4.2.2.6
1014 	 */
1015 	bool edid_corrupt;
1016 
1017 	/** @debugfs_entry: debugfs directory for this connector */
1018 	struct dentry *debugfs_entry;
1019 
1020 	/**
1021 	 * @state:
1022 	 *
1023 	 * Current atomic state for this connector.
1024 	 *
1025 	 * This is protected by &drm_mode_config.connection_mutex. Note that
1026 	 * nonblocking atomic commits access the current connector state without
1027 	 * taking locks. Either by going through the &struct drm_atomic_state
1028 	 * pointers, see for_each_oldnew_connector_in_state(),
1029 	 * for_each_old_connector_in_state() and
1030 	 * for_each_new_connector_in_state(). Or through careful ordering of
1031 	 * atomic commit operations as implemented in the atomic helpers, see
1032 	 * &struct drm_crtc_commit.
1033 	 */
1034 	struct drm_connector_state *state;
1035 
1036 	/* DisplayID bits. FIXME: Extract into a substruct? */
1037 
1038 	/**
1039 	 * @tile_blob_ptr:
1040 	 *
1041 	 * DRM blob property data for the tile property (used mostly by DP MST).
1042 	 * This is meant for screens which are driven through separate display
1043 	 * pipelines represented by &drm_crtc, which might not be running with
1044 	 * genlocked clocks. For tiled panels which are genlocked, like
1045 	 * dual-link LVDS or dual-link DSI, the driver should try to not expose
1046 	 * the tiling and virtualize both &drm_crtc and &drm_plane if needed.
1047 	 *
1048 	 * This should only be updated by calling
1049 	 * drm_connector_set_tile_property().
1050 	 */
1051 	struct drm_property_blob *tile_blob_ptr;
1052 
1053 	/** @has_tile: is this connector connected to a tiled monitor */
1054 	bool has_tile;
1055 	/** @tile_group: tile group for the connected monitor */
1056 	struct drm_tile_group *tile_group;
1057 	/** @tile_is_single_monitor: whether the tile is one monitor housing */
1058 	bool tile_is_single_monitor;
1059 
1060 	/** @num_h_tile: number of horizontal tiles in the tile group */
1061 	/** @num_v_tile: number of vertical tiles in the tile group */
1062 	uint8_t num_h_tile, num_v_tile;
1063 	/** @tile_h_loc: horizontal location of this tile */
1064 	/** @tile_v_loc: vertical location of this tile */
1065 	uint8_t tile_h_loc, tile_v_loc;
1066 	/** @tile_h_size: horizontal size of this tile. */
1067 	/** @tile_v_size: vertical size of this tile. */
1068 	uint16_t tile_h_size, tile_v_size;
1069 
1070 	/**
1071 	 * @free_node:
1072 	 *
1073 	 * List used only by &drm_connector_list_iter to be able to clean up a
1074 	 * connector from any context, in conjunction with
1075 	 * &drm_mode_config.connector_free_work.
1076 	 */
1077 	struct llist_node free_node;
1078 };
1079 
1080 #define obj_to_connector(x) container_of(x, struct drm_connector, base)
1081 
1082 int drm_connector_init(struct drm_device *dev,
1083 		       struct drm_connector *connector,
1084 		       const struct drm_connector_funcs *funcs,
1085 		       int connector_type);
1086 int drm_connector_register(struct drm_connector *connector);
1087 void drm_connector_unregister(struct drm_connector *connector);
1088 int drm_connector_attach_encoder(struct drm_connector *connector,
1089 				      struct drm_encoder *encoder);
1090 
1091 void drm_connector_cleanup(struct drm_connector *connector);
1092 
drm_connector_index(const struct drm_connector * connector)1093 static inline unsigned int drm_connector_index(const struct drm_connector *connector)
1094 {
1095 	return connector->index;
1096 }
1097 
drm_connector_mask(const struct drm_connector * connector)1098 static inline u32 drm_connector_mask(const struct drm_connector *connector)
1099 {
1100 	return 1 << connector->index;
1101 }
1102 
1103 /**
1104  * drm_connector_lookup - lookup connector object
1105  * @dev: DRM device
1106  * @file_priv: drm file to check for lease against.
1107  * @id: connector object id
1108  *
1109  * This function looks up the connector object specified by id
1110  * add takes a reference to it.
1111  */
drm_connector_lookup(struct drm_device * dev,struct drm_file * file_priv,uint32_t id)1112 static inline struct drm_connector *drm_connector_lookup(struct drm_device *dev,
1113 		struct drm_file *file_priv,
1114 		uint32_t id)
1115 {
1116 	struct drm_mode_object *mo;
1117 	mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_CONNECTOR);
1118 	return mo ? obj_to_connector(mo) : NULL;
1119 }
1120 
1121 /**
1122  * drm_connector_get - acquire a connector reference
1123  * @connector: DRM connector
1124  *
1125  * This function increments the connector's refcount.
1126  */
drm_connector_get(struct drm_connector * connector)1127 static inline void drm_connector_get(struct drm_connector *connector)
1128 {
1129 	drm_mode_object_get(&connector->base);
1130 }
1131 
1132 /**
1133  * drm_connector_put - release a connector reference
1134  * @connector: DRM connector
1135  *
1136  * This function decrements the connector's reference count and frees the
1137  * object if the reference count drops to zero.
1138  */
drm_connector_put(struct drm_connector * connector)1139 static inline void drm_connector_put(struct drm_connector *connector)
1140 {
1141 	drm_mode_object_put(&connector->base);
1142 }
1143 
1144 /**
1145  * drm_connector_reference - acquire a connector reference
1146  * @connector: DRM connector
1147  *
1148  * This is a compatibility alias for drm_connector_get() and should not be
1149  * used by new code.
1150  */
drm_connector_reference(struct drm_connector * connector)1151 static inline void drm_connector_reference(struct drm_connector *connector)
1152 {
1153 	drm_connector_get(connector);
1154 }
1155 
1156 /**
1157  * drm_connector_unreference - release a connector reference
1158  * @connector: DRM connector
1159  *
1160  * This is a compatibility alias for drm_connector_put() and should not be
1161  * used by new code.
1162  */
drm_connector_unreference(struct drm_connector * connector)1163 static inline void drm_connector_unreference(struct drm_connector *connector)
1164 {
1165 	drm_connector_put(connector);
1166 }
1167 
1168 const char *drm_get_connector_status_name(enum drm_connector_status status);
1169 const char *drm_get_subpixel_order_name(enum subpixel_order order);
1170 const char *drm_get_dpms_name(int val);
1171 const char *drm_get_dvi_i_subconnector_name(int val);
1172 const char *drm_get_dvi_i_select_name(int val);
1173 const char *drm_get_tv_subconnector_name(int val);
1174 const char *drm_get_tv_select_name(int val);
1175 const char *drm_get_content_protection_name(int val);
1176 
1177 int drm_mode_create_dvi_i_properties(struct drm_device *dev);
1178 int drm_mode_create_tv_properties(struct drm_device *dev,
1179 				  unsigned int num_modes,
1180 				  const char * const modes[]);
1181 int drm_mode_create_scaling_mode_property(struct drm_device *dev);
1182 int drm_connector_attach_content_type_property(struct drm_connector *dev);
1183 int drm_connector_attach_scaling_mode_property(struct drm_connector *connector,
1184 					       u32 scaling_mode_mask);
1185 int drm_connector_attach_content_protection_property(
1186 		struct drm_connector *connector);
1187 int drm_mode_create_aspect_ratio_property(struct drm_device *dev);
1188 int drm_mode_create_content_type_property(struct drm_device *dev);
1189 void drm_hdmi_avi_infoframe_content_type(struct hdmi_avi_infoframe *frame,
1190 					 const struct drm_connector_state *conn_state);
1191 
1192 int drm_mode_create_suggested_offset_properties(struct drm_device *dev);
1193 
1194 int drm_connector_set_path_property(struct drm_connector *connector,
1195 				    const char *path);
1196 int drm_connector_set_tile_property(struct drm_connector *connector);
1197 int drm_connector_update_edid_property(struct drm_connector *connector,
1198 				       const struct edid *edid);
1199 void drm_connector_set_link_status_property(struct drm_connector *connector,
1200 					    uint64_t link_status);
1201 int drm_connector_init_panel_orientation_property(
1202 	struct drm_connector *connector, int width, int height);
1203 
1204 /**
1205  * struct drm_tile_group - Tile group metadata
1206  * @refcount: reference count
1207  * @dev: DRM device
1208  * @id: tile group id exposed to userspace
1209  * @group_data: Sink-private data identifying this group
1210  *
1211  * @group_data corresponds to displayid vend/prod/serial for external screens
1212  * with an EDID.
1213  */
1214 struct drm_tile_group {
1215 	struct kref refcount;
1216 	struct drm_device *dev;
1217 	int id;
1218 	u8 group_data[8];
1219 };
1220 
1221 struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
1222 						  char topology[8]);
1223 struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
1224 					       char topology[8]);
1225 void drm_mode_put_tile_group(struct drm_device *dev,
1226 			     struct drm_tile_group *tg);
1227 
1228 /**
1229  * struct drm_connector_list_iter - connector_list iterator
1230  *
1231  * This iterator tracks state needed to be able to walk the connector_list
1232  * within struct drm_mode_config. Only use together with
1233  * drm_connector_list_iter_begin(), drm_connector_list_iter_end() and
1234  * drm_connector_list_iter_next() respectively the convenience macro
1235  * drm_for_each_connector_iter().
1236  */
1237 struct drm_connector_list_iter {
1238 /* private: */
1239 	struct drm_device *dev;
1240 	struct drm_connector *conn;
1241 };
1242 
1243 void drm_connector_list_iter_begin(struct drm_device *dev,
1244 				   struct drm_connector_list_iter *iter);
1245 struct drm_connector *
1246 drm_connector_list_iter_next(struct drm_connector_list_iter *iter);
1247 void drm_connector_list_iter_end(struct drm_connector_list_iter *iter);
1248 
1249 bool drm_connector_has_possible_encoder(struct drm_connector *connector,
1250 					struct drm_encoder *encoder);
1251 
1252 /**
1253  * drm_for_each_connector_iter - connector_list iterator macro
1254  * @connector: &struct drm_connector pointer used as cursor
1255  * @iter: &struct drm_connector_list_iter
1256  *
1257  * Note that @connector is only valid within the list body, if you want to use
1258  * @connector after calling drm_connector_list_iter_end() then you need to grab
1259  * your own reference first using drm_connector_get().
1260  */
1261 #define drm_for_each_connector_iter(connector, iter) \
1262 	while ((connector = drm_connector_list_iter_next(iter)))
1263 
1264 /**
1265  * drm_connector_for_each_possible_encoder - iterate connector's possible encoders
1266  * @connector: &struct drm_connector pointer
1267  * @encoder: &struct drm_encoder pointer used as cursor
1268  * @__i: int iteration cursor, for macro-internal use
1269  */
1270 #define drm_connector_for_each_possible_encoder(connector, encoder, __i) \
1271 	for ((__i) = 0; (__i) < ARRAY_SIZE((connector)->encoder_ids) && \
1272 		     (connector)->encoder_ids[(__i)] != 0; (__i)++) \
1273 		for_each_if((encoder) = \
1274 			    drm_encoder_find((connector)->dev, NULL, \
1275 					     (connector)->encoder_ids[(__i)])) \
1276 
1277 #endif
1278