3  * DisplayPort CEC-Tunneling-over-AUX support
12 #include <media/cec.h>
17  * have a converter chip that supports CEC-Tunneling-over-AUX (usually the
18  * Parade PS176), but they do not wire up the CEC pin, thus making CEC
23  * any of the other CEC devices. Quite literally the CEC wire is cut
28  * and no incentive to correctly wire up the CEC pin.
31  * finally fix their adapters and test the CEC functionality.
35  * https://hverkuil.home.xs4all.nl/cec-status.txt
40  * Note that the current implementation does not support CEC over an MST hub.
42  * standard to transport CEC interrupts over an MST device. It might be
48  * DOC: dp cec helpers
50  * These functions take care of supporting the CEC-Tunneling-over-AUX
55  * When the EDID is unset because the HPD went low, then the CEC DPCD registers
58  * short period for one reason or another, and that would cause the CEC adapter
61  * This module parameter sets a delay in seconds before the CEC adapter is
63  * the CEC adapter be unregistered.
65  * If it is set to a value >= NEVER_UNREG_DELAY, then the CEC adapter will never
68  * If it is set to 0, then the CEC adapter will be unregistered immediately as
72  * the CEC adapter.
74  * Note that for integrated HDMI branch devices that support CEC the DPCD
76  * by the HPD. In that case the CEC adapter will never be unregistered during
78  * have hardware with an integrated HDMI branch device that supports CEC.
84 		 "CEC unregister delay in seconds, 0: no delay, >= 1000: never unregister");
185 	struct cec_adapter *adap = aux->cec.adap;  in drm_dp_cec_received()
208 	struct cec_adapter *adap = aux->cec.adap;  in drm_dp_cec_handle_irq()
230  * drm_dp_cec_irq() - handle CEC interrupt, if any
233  * Should be called when handling an IRQ_HPD request. If CEC-tunneling-over-AUX
241 	mutex_lock(&aux->cec.lock);  in drm_dp_cec_irq()
242 	if (!aux->cec.adap)  in drm_dp_cec_irq()
253 	mutex_unlock(&aux->cec.lock);  in drm_dp_cec_irq()
271  * seconds. This unregisters the CEC adapter.
276 					      cec.unregister_work.work);  in drm_dp_cec_unregister_work()
278 	mutex_lock(&aux->cec.lock);  in drm_dp_cec_unregister_work()
279 	cec_unregister_adapter(aux->cec.adap);  in drm_dp_cec_unregister_work()
280 	aux->cec.adap = NULL;  in drm_dp_cec_unregister_work()
281 	mutex_unlock(&aux->cec.lock);  in drm_dp_cec_unregister_work()
285  * A new EDID is set. If there is no CEC adapter, then create one. If
286  * there was a CEC adapter, then check if the CEC adapter properties
287  * were unchanged and just update the CEC physical address. Otherwise
288  * unregister the old CEC adapter and create a new one.
306 	cancel_delayed_work_sync(&aux->cec.unregister_work);  in drm_dp_cec_set_edid()
308 	mutex_lock(&aux->cec.lock);  in drm_dp_cec_set_edid()
310 		/* CEC is not supported, unregister any existing adapter */  in drm_dp_cec_set_edid()
311 		cec_unregister_adapter(aux->cec.adap);  in drm_dp_cec_set_edid()
312 		aux->cec.adap = NULL;  in drm_dp_cec_set_edid()
321 	if (aux->cec.adap) {  in drm_dp_cec_set_edid()
322 		if (aux->cec.adap->capabilities == cec_caps &&  in drm_dp_cec_set_edid()
323 		    aux->cec.adap->available_log_addrs == num_las) {  in drm_dp_cec_set_edid()
325 			cec_s_phys_addr_from_edid(aux->cec.adap, edid);  in drm_dp_cec_set_edid()
332 		cec_unregister_adapter(aux->cec.adap);  in drm_dp_cec_set_edid()
336 	aux->cec.adap = cec_allocate_adapter(&drm_dp_cec_adap_ops,  in drm_dp_cec_set_edid()
337 					     aux, aux->cec.name, cec_caps,  in drm_dp_cec_set_edid()
339 	if (IS_ERR(aux->cec.adap)) {  in drm_dp_cec_set_edid()
340 		aux->cec.adap = NULL;  in drm_dp_cec_set_edid()
343 	if (cec_register_adapter(aux->cec.adap, aux->cec.parent)) {  in drm_dp_cec_set_edid()
344 		cec_delete_adapter(aux->cec.adap);  in drm_dp_cec_set_edid()
345 		aux->cec.adap = NULL;  in drm_dp_cec_set_edid()
348 		 * Update the phys addr for the new CEC adapter. When called  in drm_dp_cec_set_edid()
352 		cec_s_phys_addr_from_edid(aux->cec.adap, edid);  in drm_dp_cec_set_edid()
355 	mutex_unlock(&aux->cec.lock);  in drm_dp_cec_set_edid()
364 	cancel_delayed_work_sync(&aux->cec.unregister_work);  in drm_dp_cec_unset_edid()
366 	mutex_lock(&aux->cec.lock);  in drm_dp_cec_unset_edid()
367 	if (!aux->cec.adap)  in drm_dp_cec_unset_edid()
370 	cec_phys_addr_invalidate(aux->cec.adap);  in drm_dp_cec_unset_edid()
372 	 * We're done if we want to keep the CEC device  in drm_dp_cec_unset_edid()
374 	 * DPCD still indicates the CEC capability (expected for an integrated  in drm_dp_cec_unset_edid()
380 		 * Unregister the CEC adapter after drm_dp_cec_unregister_delay  in drm_dp_cec_unset_edid()
384 		schedule_delayed_work(&aux->cec.unregister_work,  in drm_dp_cec_unset_edid()
388 	mutex_unlock(&aux->cec.lock);  in drm_dp_cec_unset_edid()
395  * @name: name of the CEC device
398  * A new connector was registered with associated CEC adapter name and
399  * CEC adapter parent device. After registering the name and parent
401  * CEC and to register a CEC adapter if that is the case.
406 	WARN_ON(aux->cec.adap);  in drm_dp_cec_register_connector()
407 	aux->cec.name = name;  in drm_dp_cec_register_connector()
408 	aux->cec.parent = parent;  in drm_dp_cec_register_connector()
409 	INIT_DELAYED_WORK(&aux->cec.unregister_work,  in drm_dp_cec_register_connector()
417  * drm_dp_cec_unregister_connector() - unregister the CEC adapter, if any
422 	if (!aux->cec.adap)  in drm_dp_cec_unregister_connector()
424 	cancel_delayed_work_sync(&aux->cec.unregister_work);  in drm_dp_cec_unregister_connector()
425 	cec_unregister_adapter(aux->cec.adap);  in drm_dp_cec_unregister_connector()
426 	aux->cec.adap = NULL;  in drm_dp_cec_unregister_connector()