1 // SPDX-License-Identifier: MIT
3  * Copyright (C) 2020 - 2021 Red Hat, Inc.
24  * register a privacy-screen device, which the KMS drivers can then use
25  * to implement the standard privacy-screen properties, see
28  * KMS drivers using a privacy-screen class device are advised to use the
45  * drm_privacy_screen_lookup_add - add an entry to the static privacy-screen
49  * Add an entry to the static privacy-screen lookup list. Note the
51  * gets added to a list owned by the privacy-screen core. So the passed in
52  * &struct drm_privacy_screen_lookup must not be free-ed until it is removed
58 	list_add(&lookup->list, &drm_privacy_screen_lookup_list);  in drm_privacy_screen_lookup_add()
64  * drm_privacy_screen_lookup_remove - remove an entry to the static
65  *    privacy-screen lookup list
69  * from the static privacy-screen lookup list.
74 	list_del(&lookup->list);  in drm_privacy_screen_lookup_remove()
90 		if (strcmp(dev_name(&priv->dev), name) == 0) {  in drm_privacy_screen_get_by_name()
91 			dev = get_device(&priv->dev);  in drm_privacy_screen_get_by_name()
102  * drm_privacy_screen_get - get a privacy-screen provider
103  * @dev: consumer-device for which to get a privacy-screen provider
104  * @con_id: (video)connector name for which to get a privacy-screen provider
106  * Get a privacy-screen provider for a privacy-screen attached to the
111  * * ERR_PTR(-ENODEV) if no matching privacy-screen is found
112  * * ERR_PTR(-EPROBE_DEFER) if there is a matching privacy-screen,
122 	int match, best = -1;  in drm_privacy_screen_get()
127 	 * be extended with device-tree / fw_node lookup when support is added  in drm_privacy_screen_get()
128 	 * for device-tree using hardware with a privacy-screen.  in drm_privacy_screen_get()
137 	 * Then we take the most specific entry - with the following order  in drm_privacy_screen_get()
145 		if (l->dev_id) {  in drm_privacy_screen_get()
146 			if (!dev_id || strcmp(l->dev_id, dev_id))  in drm_privacy_screen_get()
152 		if (l->con_id) {  in drm_privacy_screen_get()
153 			if (!con_id || strcmp(l->con_id, con_id))  in drm_privacy_screen_get()
160 			provider = l->provider;  in drm_privacy_screen_get()
168 		return ERR_PTR(-ENODEV);  in drm_privacy_screen_get()
172 		return ERR_PTR(-EPROBE_DEFER);  in drm_privacy_screen_get()
179  * drm_privacy_screen_put - release a privacy-screen reference
182  * Release a privacy-screen provider reference gotten through
184  * in which case it is a no-op.
191 	put_device(&priv->dev);  in drm_privacy_screen_put()
196  * drm_privacy_screen_set_sw_state - set a privacy-screen's sw-state
197  * @priv: privacy screen to set the sw-state for
198  * @sw_state: new sw-state value to set
200  * Set the sw-state of a privacy screen. If the privacy-screen is not
201  * in a locked hw-state, then the actual and hw-state of the privacy-screen
202  * will be immediately updated to the new value. If the privacy-screen is
203  * in a locked hw-state, then the new sw-state will be remembered as the
204  * requested state to put the privacy-screen in when it becomes unlocked.
213 	mutex_lock(&priv->lock);  in drm_privacy_screen_set_sw_state()
215 	if (!priv->ops) {  in drm_privacy_screen_set_sw_state()
216 		ret = -ENODEV;  in drm_privacy_screen_set_sw_state()
222 	 * sw_state while the hw_state is locked is allowed. In this case  in drm_privacy_screen_set_sw_state()
223 	 * it is a no-op other then storing the new sw_state so that it  in drm_privacy_screen_set_sw_state()
227 	if (priv->hw_state >= PRIVACY_SCREEN_DISABLED_LOCKED ||  in drm_privacy_screen_set_sw_state()
228 	    priv->hw_state == sw_state) {  in drm_privacy_screen_set_sw_state()
229 		priv->sw_state = sw_state;  in drm_privacy_screen_set_sw_state()
233 	ret = priv->ops->set_sw_state(priv, sw_state);  in drm_privacy_screen_set_sw_state()
235 	mutex_unlock(&priv->lock);  in drm_privacy_screen_set_sw_state()
241  * drm_privacy_screen_get_state - get privacy-screen's current state
243  * @sw_state_ret: address where to store the privacy-screens current sw-state
244  * @hw_state_ret: address where to store the privacy-screens current hw-state
246  * Get the current state of a privacy-screen, both the sw-state and the
247  * hw-state.
253 	mutex_lock(&priv->lock);  in drm_privacy_screen_get_state()
254 	*sw_state_ret = priv->sw_state;  in drm_privacy_screen_get_state()
255 	*hw_state_ret = priv->hw_state;  in drm_privacy_screen_get_state()
256 	mutex_unlock(&priv->lock);  in drm_privacy_screen_get_state()
261  * drm_privacy_screen_register_notifier - register a notifier
263  * @nb: Notifier-block for the notifier to register
265  * Register a notifier with the privacy-screen to be notified of changes made
266  * to the privacy-screen state from outside of the privacy-screen class.
283 	return blocking_notifier_chain_register(&priv->notifier_head, nb);  in drm_privacy_screen_register_notifier()
288  * drm_privacy_screen_unregister_notifier - unregister a notifier
290  * @nb: Notifier-block for the notifier to register
299 	return blocking_notifier_chain_unregister(&priv->notifier_head, nb);  in drm_privacy_screen_unregister_notifier()
315 	mutex_lock(&priv->lock);  in sw_state_show()
317 	if (!priv->ops)  in sw_state_show()
318 		ret = -ENODEV;  in sw_state_show()
319 	else if (WARN_ON(priv->sw_state >= ARRAY_SIZE(sw_state_names)))  in sw_state_show()
320 		ret = -ENXIO;  in sw_state_show()
322 		ret = sprintf(buf, "%s\n", sw_state_names[priv->sw_state]);  in sw_state_show()
324 	mutex_unlock(&priv->lock);  in sw_state_show()
340 		"Disabled, locked",  in hw_state_show()
341 		"Enabled, locked",  in hw_state_show()
345 	mutex_lock(&priv->lock);  in hw_state_show()
347 	if (!priv->ops)  in hw_state_show()
348 		ret = -ENODEV;  in hw_state_show()
349 	else if (WARN_ON(priv->hw_state >= ARRAY_SIZE(hw_state_names)))  in hw_state_show()
350 		ret = -ENXIO;  in hw_state_show()
352 		ret = sprintf(buf, "%s\n", hw_state_names[priv->hw_state]);  in hw_state_show()
354 	mutex_unlock(&priv->lock);  in hw_state_show()
379  * drm_privacy_screen_register - register a privacy-screen
380  * @parent: parent-device for the privacy-screen
381  * @ops: &struct drm_privacy_screen_ops pointer with ops for the privacy-screen
384  * Create and register a privacy-screen.
387  * * A pointer to the created privacy-screen on success.
391 	struct device *parent, const struct drm_privacy_screen_ops *ops,  in drm_privacy_screen_register()  argument
399 		return ERR_PTR(-ENOMEM);  in drm_privacy_screen_register()
401 	mutex_init(&priv->lock);  in drm_privacy_screen_register()
402 	BLOCKING_INIT_NOTIFIER_HEAD(&priv->notifier_head);  in drm_privacy_screen_register()
404 	priv->dev.class = drm_class;  in drm_privacy_screen_register()
405 	priv->dev.type = &drm_privacy_screen_type;  in drm_privacy_screen_register()
406 	priv->dev.parent = parent;  in drm_privacy_screen_register()
407 	priv->dev.release = drm_privacy_screen_device_release;  in drm_privacy_screen_register()
408 	dev_set_name(&priv->dev, "privacy_screen-%s", dev_name(parent));  in drm_privacy_screen_register()
409 	priv->drvdata = data;  in drm_privacy_screen_register()
410 	priv->ops = ops;  in drm_privacy_screen_register()
412 	priv->ops->get_hw_state(priv);  in drm_privacy_screen_register()
414 	ret = device_register(&priv->dev);  in drm_privacy_screen_register()
416 		put_device(&priv->dev);  in drm_privacy_screen_register()
421 	list_add(&priv->list, &drm_privacy_screen_devs);  in drm_privacy_screen_register()
429  * drm_privacy_screen_unregister - unregister privacy-screen
430  * @priv: privacy-screen to unregister
432  * Unregister a privacy-screen registered with drm_privacy_screen_register().
433  * May be called with a NULL or ERR_PTR, in which case it is a no-op.
441 	list_del(&priv->list);  in drm_privacy_screen_unregister()
444 	mutex_lock(&priv->lock);  in drm_privacy_screen_unregister()
445 	priv->drvdata = NULL;  in drm_privacy_screen_unregister()
446 	priv->ops = NULL;  in drm_privacy_screen_unregister()
447 	mutex_unlock(&priv->lock);  in drm_privacy_screen_unregister()
449 	device_unregister(&priv->dev);  in drm_privacy_screen_unregister()
454  * drm_privacy_screen_call_notifier_chain - notify consumers of state change
457  * A privacy-screen provider driver can call this functions upon external
458  * changes to the privacy-screen state. E.g. the state may be changed by the
460  * This function must be called without holding the privacy-screen lock.
469 	blocking_notifier_call_chain(&priv->notifier_head, 0, priv);  in drm_privacy_screen_call_notifier_chain()