3  * DisplayPort CEC-Tunneling-over-AUX support
12 #include <media/cec.h>
22  * have a converter chip that supports CEC-Tunneling-over-AUX (usually the
23  * Parade PS176), but they do not wire up the CEC pin, thus making CEC
25  * support for CEC tunneling. Those adapters that I have tested using
26  * this chipset all have the CEC line connected.
30  * any of the other CEC devices. Quite literally the CEC wire is cut
35  * and no incentive to correctly wire up the CEC pin.
38  * finally fix their adapters and test the CEC functionality.
42  * https://hverkuil.home.xs4all.nl/cec-status.txt
47  * Note that the current implementation does not support CEC over an MST hub.
49  * standard to transport CEC interrupts over an MST device. It might be
55  * DOC: dp cec helpers
57  * These functions take care of supporting the CEC-Tunneling-over-AUX
62  * When the EDID is unset because the HPD went low, then the CEC DPCD registers
65  * short period for one reason or another, and that would cause the CEC adapter
68  * This module parameter sets a delay in seconds before the CEC adapter is
70  * the CEC adapter be unregistered.
72  * If it is set to a value >= NEVER_UNREG_DELAY, then the CEC adapter will never
75  * If it is set to 0, then the CEC adapter will be unregistered immediately as
79  * the CEC adapter.
81  * Note that for integrated HDMI branch devices that support CEC the DPCD
83  * by the HPD. In that case the CEC adapter will never be unregistered during
85  * have hardware with an integrated HDMI branch device that supports CEC.
91 		 "CEC unregister delay in seconds, 0: no delay, >= 1000: never unregister");
192 	struct cec_adapter *adap = aux->cec.adap;  in drm_dp_cec_received()
215 	struct cec_adapter *adap = aux->cec.adap;  in drm_dp_cec_handle_irq()
237  * drm_dp_cec_irq() - handle CEC interrupt, if any
240  * Should be called when handling an IRQ_HPD request. If CEC-tunneling-over-AUX
252 	mutex_lock(&aux->cec.lock);  in drm_dp_cec_irq()
253 	if (!aux->cec.adap)  in drm_dp_cec_irq()
264 	mutex_unlock(&aux->cec.lock);  in drm_dp_cec_irq()
282  * seconds. This unregisters the CEC adapter.
287 					      cec.unregister_work.work);  in drm_dp_cec_unregister_work()
289 	mutex_lock(&aux->cec.lock);  in drm_dp_cec_unregister_work()
290 	cec_unregister_adapter(aux->cec.adap);  in drm_dp_cec_unregister_work()
291 	aux->cec.adap = NULL;  in drm_dp_cec_unregister_work()
292 	mutex_unlock(&aux->cec.lock);  in drm_dp_cec_unregister_work()
296  * A new EDID is set. If there is no CEC adapter, then create one. If
297  * there was a CEC adapter, then check if the CEC adapter properties
298  * were unchanged and just update the CEC physical address. Otherwise
299  * unregister the old CEC adapter and create a new one.
303 	struct drm_connector *connector = aux->cec.connector;  in drm_dp_cec_attach()
324 	cancel_delayed_work_sync(&aux->cec.unregister_work);  in drm_dp_cec_attach()
326 	mutex_lock(&aux->cec.lock);  in drm_dp_cec_attach()
328 		/* CEC is not supported, unregister any existing adapter */  in drm_dp_cec_attach()
329 		cec_unregister_adapter(aux->cec.adap);  in drm_dp_cec_attach()
330 		aux->cec.adap = NULL;  in drm_dp_cec_attach()
339 	if (aux->cec.adap) {  in drm_dp_cec_attach()
340 		if (aux->cec.adap->capabilities == cec_caps &&  in drm_dp_cec_attach()
341 		    aux->cec.adap->available_log_addrs == num_las) {  in drm_dp_cec_attach()
343 			cec_s_phys_addr(aux->cec.adap, source_physical_address, false);  in drm_dp_cec_attach()
350 		cec_unregister_adapter(aux->cec.adap);  in drm_dp_cec_attach()
354 	aux->cec.adap = cec_allocate_adapter(&drm_dp_cec_adap_ops,  in drm_dp_cec_attach()
357 	if (IS_ERR(aux->cec.adap)) {  in drm_dp_cec_attach()
358 		aux->cec.adap = NULL;  in drm_dp_cec_attach()
363 	cec_s_conn_info(aux->cec.adap, &conn_info);  in drm_dp_cec_attach()
365 	if (cec_register_adapter(aux->cec.adap, connector->dev->dev)) {  in drm_dp_cec_attach()
366 		cec_delete_adapter(aux->cec.adap);  in drm_dp_cec_attach()
367 		aux->cec.adap = NULL;  in drm_dp_cec_attach()
370 		 * Update the phys addr for the new CEC adapter. When called  in drm_dp_cec_attach()
374 		cec_s_phys_addr(aux->cec.adap, source_physical_address, false);  in drm_dp_cec_attach()
377 	mutex_unlock(&aux->cec.lock);  in drm_dp_cec_attach()
406 	cancel_delayed_work_sync(&aux->cec.unregister_work);  in drm_dp_cec_unset_edid()
408 	mutex_lock(&aux->cec.lock);  in drm_dp_cec_unset_edid()
409 	if (!aux->cec.adap)  in drm_dp_cec_unset_edid()
412 	cec_phys_addr_invalidate(aux->cec.adap);  in drm_dp_cec_unset_edid()
414 	 * We're done if we want to keep the CEC device  in drm_dp_cec_unset_edid()
416 	 * DPCD still indicates the CEC capability (expected for an integrated  in drm_dp_cec_unset_edid()
422 		 * Unregister the CEC adapter after drm_dp_cec_unregister_delay  in drm_dp_cec_unset_edid()
426 		schedule_delayed_work(&aux->cec.unregister_work,  in drm_dp_cec_unset_edid()
430 	mutex_unlock(&aux->cec.lock);  in drm_dp_cec_unset_edid()
439  * A new connector was registered with associated CEC adapter name and
440  * CEC adapter parent device. After registering the name and parent
442  * CEC and to register a CEC adapter if that is the case.
447 	WARN_ON(aux->cec.adap);  in drm_dp_cec_register_connector()
450 	aux->cec.connector = connector;  in drm_dp_cec_register_connector()
451 	INIT_DELAYED_WORK(&aux->cec.unregister_work,  in drm_dp_cec_register_connector()
457  * drm_dp_cec_unregister_connector() - unregister the CEC adapter, if any
462 	if (!aux->cec.adap)  in drm_dp_cec_unregister_connector()
464 	cancel_delayed_work_sync(&aux->cec.unregister_work);  in drm_dp_cec_unregister_connector()
465 	cec_unregister_adapter(aux->cec.adap);  in drm_dp_cec_unregister_connector()
466 	aux->cec.adap = NULL;  in drm_dp_cec_unregister_connector()