drivers/net/wireless/intel/iwlwifi/mvm/time-event.h

/******************************************************************************
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 * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
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#ifndef __time_event_h__
#define __time_event_h__

#include "fw-api.h"

#include "mvm.h"

/**
 * DOC: Time Events - what is it?
 *
 * Time Events are a fw feature that allows the driver to control the presence
 * of the device on the channel. Since the fw supports multiple channels
 * concurrently, the fw may choose to jump to another channel at any time.
 * In order to make sure that the fw is on a specific channel at a certain time
 * and for a certain duration, the driver needs to issue a time event.
 *
 * The simplest example is for BSS association. The driver issues a time event,
 * waits for it to start, and only then tells mac80211 that we can start the
 * association. This way, we make sure that the association will be done
 * smoothly and won't be interrupted by channel switch decided within the fw.
 */

 /**
 * DOC: The flow against the fw
 *
 * When the driver needs to make sure we are in a certain channel, at a certain
 * time and for a certain duration, it sends a Time Event. The flow against the
 * fw goes like this:
 *	1) Driver sends a TIME_EVENT_CMD to the fw
 *	2) Driver gets the response for that command. This response contains the
 *	   Unique ID (UID) of the event.
 *	3) The fw sends notification when the event starts.
 *
 * Of course the API provides various options that allow to cover parameters
 * of the flow.
 *	What is the duration of the event?
 *	What is the start time of the event?
 *	Is there an end-time for the event?
 *	How much can the event be delayed?
 *	Can the event be split?
 *	If yes what is the maximal number of chunks?
 *	etc...
 */

/**
 * DOC: Abstraction to the driver
 *
 * In order to simplify the use of time events to the rest of the driver,
 * we abstract the use of time events. This component provides the functions
 * needed by the driver.
 */

#define IWL_MVM_TE_SESSION_PROTECTION_MAX_TIME_MS 600
#define IWL_MVM_TE_SESSION_PROTECTION_MIN_TIME_MS 400

/**
 * iwl_mvm_protect_session - start / extend the session protection.
 * @mvm: the mvm component
 * @vif: the virtual interface for which the session is issued
 * @duration: the duration of the session in TU.
 * @min_duration: will start a new session if the current session will end
 *	in less than min_duration.
 * @max_delay: maximum delay before starting the time event (in TU)
 * @wait_for_notif: true if it is required that a time event notification be
 *	waited for (that the time event has been scheduled before returning)
 *
 * This function can be used to start a session protection which means that the
 * fw will stay on the channel for %duration_ms milliseconds. This function
 * can block (sleep) until the session starts. This function can also be used
 * to extend a currently running session.
 * This function is meant to be used for BSS association for example, where we
 * want to make sure that the fw stays on the channel during the association.
 */
void iwl_mvm_protect_session(struct iwl_mvm *mvm,
			     struct ieee80211_vif *vif,
			     u32 duration, u32 min_duration,
			     u32 max_delay, bool wait_for_notif);

/**
 * iwl_mvm_stop_session_protection - cancel the session protection.
 * @mvm: the mvm component
 * @vif: the virtual interface for which the session is issued
 *
 * This functions cancels the session protection which is an act of good
 * citizenship. If it is not needed any more it should be canceled because
 * the other bindings wait for the medium during that time.
 * This funtions doesn't sleep.
 */
void iwl_mvm_stop_session_protection(struct iwl_mvm *mvm,
				      struct ieee80211_vif *vif);

/*
 * iwl_mvm_rx_time_event_notif - handles %TIME_EVENT_NOTIFICATION.
 */
void iwl_mvm_rx_time_event_notif(struct iwl_mvm *mvm,
				 struct iwl_rx_cmd_buffer *rxb);

/**
 * iwl_mvm_start_p2p_roc - start remain on channel for p2p device functionality
 * @mvm: the mvm component
 * @vif: the virtual interface for which the roc is requested. It is assumed
 * that the vif type is NL80211_IFTYPE_P2P_DEVICE
 * @duration: the requested duration in millisecond for the fw to be on the
 * channel that is bound to the vif.
 * @type: the remain on channel request type
 *
 * This function can be used to issue a remain on channel session,
 * which means that the fw will stay in the channel for the request %duration
 * milliseconds. The function is async, meaning that it only issues the ROC
 * request but does not wait for it to start. Once the FW is ready to serve the
 * ROC request, it will issue a notification to the driver that it is on the
 * requested channel. Once the FW completes the ROC request it will issue
 * another notification to the driver.
 */
int iwl_mvm_start_p2p_roc(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
			  int duration, enum ieee80211_roc_type type);

/**
 * iwl_mvm_stop_roc - stop remain on channel functionality
 * @mvm: the mvm component
 *
 * This function can be used to cancel an ongoing ROC session.
 * The function is async, it will instruct the FW to stop serving the ROC
 * session, but will not wait for the actual stopping of the session.
 */
void iwl_mvm_stop_roc(struct iwl_mvm *mvm);

/**
 * iwl_mvm_remove_time_event - general function to clean up of time event
 * @mvm: the mvm component
 * @vif: the vif to which the time event belongs
 * @te_data: the time event data that corresponds to that time event
 *
 * This function can be used to cancel a time event regardless its type.
 * It is useful for cleaning up time events running before removing an
 * interface.
 */
void iwl_mvm_remove_time_event(struct iwl_mvm *mvm,
			       struct iwl_mvm_vif *mvmvif,
			       struct iwl_mvm_time_event_data *te_data);

/**
 * iwl_mvm_te_clear_data - remove time event from list
 * @mvm: the mvm component
 * @te_data: the time event data to remove
 *
 * This function is mostly internal, it is made available here only
 * for firmware restart purposes.
 */
void iwl_mvm_te_clear_data(struct iwl_mvm *mvm,
			   struct iwl_mvm_time_event_data *te_data);

void iwl_mvm_cleanup_roc_te(struct iwl_mvm *mvm);
void iwl_mvm_roc_done_wk(struct work_struct *wk);

/**
 * iwl_mvm_schedule_csa_period - request channel switch absence period
 * @mvm: the mvm component
 * @vif: the virtual interface for which the channel switch is issued
 * @duration: the duration of the NoA in TU.
 * @apply_time: NoA start time in GP2.
 *
 * This function is used to schedule NoA time event and is used to perform
 * the channel switch flow.
 */
int iwl_mvm_schedule_csa_period(struct iwl_mvm *mvm,
				struct ieee80211_vif *vif,
				u32 duration, u32 apply_time);

/**
 * iwl_mvm_te_scheduled - check if the fw received the TE cmd
 * @te_data: the time event data that corresponds to that time event
 *
 * This function returns true iff this TE is added to the fw.
 */
static inline bool
iwl_mvm_te_scheduled(struct iwl_mvm_time_event_data *te_data)
{
	if (!te_data)
		return false;

	return !!te_data->uid;
}

#endif /* __time_event_h__ */