aha/include/linux/rfkill.h
Johannes Berg 19d337dff9 rfkill: rewrite
This patch completely rewrites the rfkill core to address
the following deficiencies:

 * all rfkill drivers need to implement polling where necessary
   rather than having one central implementation

 * updating the rfkill state cannot be done from arbitrary
   contexts, forcing drivers to use schedule_work and requiring
   lots of code

 * rfkill drivers need to keep track of soft/hard blocked
   internally -- the core should do this

 * the rfkill API has many unexpected quirks, for example being
   asymmetric wrt. alloc/free and register/unregister

 * rfkill can call back into a driver from within a function the
   driver called -- this is prone to deadlocks and generally
   should be avoided

 * rfkill-input pointlessly is a separate module

 * drivers need to #ifdef rfkill functions (unless they want to
   depend on or select RFKILL) -- rfkill should provide inlines
   that do nothing if it isn't compiled in

 * the rfkill structure is not opaque -- drivers need to initialise
   it correctly (lots of sanity checking code required) -- instead
   force drivers to pass the right variables to rfkill_alloc()

 * the documentation is hard to read because it always assumes the
   reader is completely clueless and contains way TOO MANY CAPS

 * the rfkill code needlessly uses a lot of locks and atomic
   operations in locked sections

 * fix LED trigger to actually change the LED when the radio state
   changes -- this wasn't done before

Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> [thinkpad]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-06-03 14:06:13 -04:00

315 lines
9.8 KiB
C

#ifndef __RFKILL_H
#define __RFKILL_H
/*
* Copyright (C) 2006 - 2007 Ivo van Doorn
* Copyright (C) 2007 Dmitry Torokhov
* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* define userspace visible states */
#define RFKILL_STATE_SOFT_BLOCKED 0
#define RFKILL_STATE_UNBLOCKED 1
#define RFKILL_STATE_HARD_BLOCKED 2
/* and that's all userspace gets */
#ifdef __KERNEL__
/* don't allow anyone to use these in the kernel */
enum rfkill_user_states {
RFKILL_USER_STATE_SOFT_BLOCKED = RFKILL_STATE_SOFT_BLOCKED,
RFKILL_USER_STATE_UNBLOCKED = RFKILL_STATE_UNBLOCKED,
RFKILL_USER_STATE_HARD_BLOCKED = RFKILL_STATE_HARD_BLOCKED,
};
#undef RFKILL_STATE_SOFT_BLOCKED
#undef RFKILL_STATE_UNBLOCKED
#undef RFKILL_STATE_HARD_BLOCKED
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/leds.h>
/**
* enum rfkill_type - type of rfkill switch.
*
* @RFKILL_TYPE_WLAN: switch is on a 802.11 wireless network device.
* @RFKILL_TYPE_BLUETOOTH: switch is on a bluetooth device.
* @RFKILL_TYPE_UWB: switch is on a ultra wideband device.
* @RFKILL_TYPE_WIMAX: switch is on a WiMAX device.
* @RFKILL_TYPE_WWAN: switch is on a wireless WAN device.
* @NUM_RFKILL_TYPES: number of defined rfkill types
*/
enum rfkill_type {
RFKILL_TYPE_WLAN,
RFKILL_TYPE_BLUETOOTH,
RFKILL_TYPE_UWB,
RFKILL_TYPE_WIMAX,
RFKILL_TYPE_WWAN,
NUM_RFKILL_TYPES,
};
/* this is opaque */
struct rfkill;
/**
* struct rfkill_ops - rfkill driver methods
*
* @poll: poll the rfkill block state(s) -- only assign this method
* when you need polling. When called, simply call one of the
* rfkill_set{,_hw,_sw}_state family of functions. If the hw
* is getting unblocked you need to take into account the return
* value of those functions to make sure the software block is
* properly used.
* @query: query the rfkill block state(s) and call exactly one of the
* rfkill_set{,_hw,_sw}_state family of functions. Assign this
* method if input events can cause hardware state changes to make
* the rfkill core query your driver before setting a requested
* block.
* @set_block: turn the transmitter on (blocked == false) or off
* (blocked == true) -- this is called only while the transmitter
* is not hard-blocked, but note that the core's view of whether
* the transmitter is hard-blocked might differ from your driver's
* view due to race conditions, so it is possible that it is still
* called at the same time as you are calling rfkill_set_hw_state().
* This callback must be assigned.
*/
struct rfkill_ops {
void (*poll)(struct rfkill *rfkill, void *data);
void (*query)(struct rfkill *rfkill, void *data);
int (*set_block)(void *data, bool blocked);
};
#if defined(CONFIG_RFKILL) || defined(CONFIG_RFKILL_MODULE)
/**
* rfkill_alloc - allocate rfkill structure
* @name: name of the struct -- the string is not copied internally
* @parent: device that has rf switch on it
* @type: type of the switch (RFKILL_TYPE_*)
* @ops: rfkill methods
* @ops_data: data passed to each method
*
* This function should be called by the transmitter driver to allocate an
* rfkill structure. Returns %NULL on failure.
*/
struct rfkill * __must_check rfkill_alloc(const char *name,
struct device *parent,
const enum rfkill_type type,
const struct rfkill_ops *ops,
void *ops_data);
/**
* rfkill_register - Register a rfkill structure.
* @rfkill: rfkill structure to be registered
*
* This function should be called by the transmitter driver to register
* the rfkill structure needs to be registered. Before calling this function
* the driver needs to be ready to service method calls from rfkill.
*/
int __must_check rfkill_register(struct rfkill *rfkill);
/**
* rfkill_pause_polling(struct rfkill *rfkill)
*
* Pause polling -- say transmitter is off for other reasons.
* NOTE: not necessary for suspend/resume -- in that case the
* core stops polling anyway
*/
void rfkill_pause_polling(struct rfkill *rfkill);
/**
* rfkill_resume_polling(struct rfkill *rfkill)
*
* Pause polling -- say transmitter is off for other reasons.
* NOTE: not necessary for suspend/resume -- in that case the
* core stops polling anyway
*/
void rfkill_resume_polling(struct rfkill *rfkill);
/**
* rfkill_unregister - Unregister a rfkill structure.
* @rfkill: rfkill structure to be unregistered
*
* This function should be called by the network driver during device
* teardown to destroy rfkill structure. Until it returns, the driver
* needs to be able to service method calls.
*/
void rfkill_unregister(struct rfkill *rfkill);
/**
* rfkill_destroy - free rfkill structure
* @rfkill: rfkill structure to be destroyed
*
* Destroys the rfkill structure.
*/
void rfkill_destroy(struct rfkill *rfkill);
/**
* rfkill_set_hw_state - Set the internal rfkill hardware block state
* @rfkill: pointer to the rfkill class to modify.
* @state: the current hardware block state to set
*
* rfkill drivers that get events when the hard-blocked state changes
* use this function to notify the rfkill core (and through that also
* userspace) of the current state -- they should also use this after
* resume if the state could have changed.
*
* You need not (but may) call this function if poll_state is assigned.
*
* This function can be called in any context, even from within rfkill
* callbacks.
*
* The function returns the combined block state (true if transmitter
* should be blocked) so that drivers need not keep track of the soft
* block state -- which they might not be able to.
*/
bool __must_check rfkill_set_hw_state(struct rfkill *rfkill, bool blocked);
/**
* rfkill_set_sw_state - Set the internal rfkill software block state
* @rfkill: pointer to the rfkill class to modify.
* @state: the current software block state to set
*
* rfkill drivers that get events when the soft-blocked state changes
* (yes, some platforms directly act on input but allow changing again)
* use this function to notify the rfkill core (and through that also
* userspace) of the current state -- they should also use this after
* resume if the state could have changed.
*
* This function can be called in any context, even from within rfkill
* callbacks.
*
* The function returns the combined block state (true if transmitter
* should be blocked).
*/
bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked);
/**
* rfkill_set_states - Set the internal rfkill block states
* @rfkill: pointer to the rfkill class to modify.
* @sw: the current software block state to set
* @hw: the current hardware block state to set
*
* This function can be called in any context, even from within rfkill
* callbacks.
*/
void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw);
/**
* rfkill_set_global_sw_state - set global sw block default
* @type: rfkill type to set default for
* @blocked: default to set
*
* This function sets the global default -- use at boot if your platform has
* an rfkill switch. If not early enough this call may be ignored.
*
* XXX: instead of ignoring -- how about just updating all currently
* registered drivers?
*/
void rfkill_set_global_sw_state(const enum rfkill_type type, bool blocked);
#else /* !RFKILL */
static inline struct rfkill * __must_check
rfkill_alloc(const char *name,
struct device *parent,
const enum rfkill_type type,
const struct rfkill_ops *ops,
void *ops_data)
{
return ERR_PTR(-ENODEV);
}
static inline int __must_check rfkill_register(struct rfkill *rfkill)
{
if (rfkill == ERR_PTR(-ENODEV))
return 0;
return -EINVAL;
}
static inline void rfkill_pause_polling(struct rfkill *rfkill)
{
}
static inline void rfkill_resume_polling(struct rfkill *rfkill)
{
}
static inline void rfkill_unregister(struct rfkill *rfkill)
{
}
static inline void rfkill_destroy(struct rfkill *rfkill)
{
}
static inline bool rfkill_set_hw_state(struct rfkill *rfkill, bool blocked)
{
return blocked;
}
static inline bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
{
return blocked;
}
static inline void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
{
}
static inline void rfkill_set_global_sw_state(const enum rfkill_type type,
bool blocked)
{
}
#endif /* RFKILL || RFKILL_MODULE */
#ifdef CONFIG_RFKILL_LEDS
/**
* rfkill_get_led_trigger_name - Get the LED trigger name for the button's LED.
* This function might return a NULL pointer if registering of the
* LED trigger failed. Use this as "default_trigger" for the LED.
*/
const char *rfkill_get_led_trigger_name(struct rfkill *rfkill);
/**
* rfkill_set_led_trigger_name -- set the LED trigger name
* @rfkill: rfkill struct
* @name: LED trigger name
*
* This function sets the LED trigger name of the radio LED
* trigger that rfkill creates. It is optional, but if called
* must be called before rfkill_register() to be effective.
*/
void rfkill_set_led_trigger_name(struct rfkill *rfkill, const char *name);
#else
static inline const char *rfkill_get_led_trigger_name(struct rfkill *rfkill)
{
return NULL;
}
static inline void
rfkill_set_led_trigger_name(struct rfkill *rfkill, const char *name)
{
}
#endif
#endif /* __KERNEL__ */
#endif /* RFKILL_H */