From 19d337dff95cbf76edd3ad95c0cee2732c3e1ec5 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 2 Jun 2009 13:01:37 +0200 Subject: 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 Signed-off-by: Henrique de Moraes Holschuh [thinkpad] Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- include/linux/rfkill.h | 325 ++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 251 insertions(+), 74 deletions(-) (limited to 'include/linux/rfkill.h') diff --git a/include/linux/rfkill.h b/include/linux/rfkill.h index de18ef227e0..090852c8de7 100644 --- a/include/linux/rfkill.h +++ b/include/linux/rfkill.h @@ -4,6 +4,7 @@ /* * Copyright (C) 2006 - 2007 Ivo van Doorn * Copyright (C) 2007 Dmitry Torokhov + * Copyright 2009 Johannes Berg * * 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 @@ -21,6 +22,24 @@ * 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 #include #include @@ -30,109 +49,267 @@ /** * 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. + * + * @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_WLAN, RFKILL_TYPE_BLUETOOTH, RFKILL_TYPE_UWB, RFKILL_TYPE_WIMAX, RFKILL_TYPE_WWAN, - RFKILL_TYPE_MAX, + NUM_RFKILL_TYPES, }; -enum rfkill_state { - RFKILL_STATE_SOFT_BLOCKED = 0, /* Radio output blocked */ - RFKILL_STATE_UNBLOCKED = 1, /* Radio output allowed */ - RFKILL_STATE_HARD_BLOCKED = 2, /* Output blocked, non-overrideable */ - RFKILL_STATE_MAX, /* marker for last valid state */ +/* 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) /** - * struct rfkill - rfkill control structure. - * @name: Name of the switch. - * @type: Radio type which the button controls, the value stored - * here should be a value from enum rfkill_type. - * @state: State of the switch, "UNBLOCKED" means radio can operate. - * @mutex: Guards switch state transitions. It serializes callbacks - * and also protects the state. - * @data: Pointer to the RF button drivers private data which will be - * passed along when toggling radio state. - * @toggle_radio(): Mandatory handler to control state of the radio. - * only RFKILL_STATE_SOFT_BLOCKED and RFKILL_STATE_UNBLOCKED are - * valid parameters. - * @get_state(): handler to read current radio state from hardware, - * may be called from atomic context, should return 0 on success. - * Either this handler OR judicious use of rfkill_force_state() is - * MANDATORY for any driver capable of RFKILL_STATE_HARD_BLOCKED. - * @led_trigger: A LED trigger for this button's LED. - * @dev: Device structure integrating the switch into device tree. - * @node: Used to place switch into list of all switches known to the - * the system. - * - * This structure represents a RF switch located on a network device. + * 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 { - const char *name; - enum rfkill_type type; - - /* the mutex serializes callbacks and also protects - * the state */ - struct mutex mutex; - enum rfkill_state state; - void *data; - int (*toggle_radio)(void *data, enum rfkill_state state); - int (*get_state)(void *data, enum rfkill_state *state); +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); -#ifdef CONFIG_RFKILL_LEDS - struct led_trigger led_trigger; -#endif +/** + * 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); - struct device dev; - struct list_head node; - enum rfkill_state state_for_resume; -}; -#define to_rfkill(d) container_of(d, struct rfkill, dev) +/** + * 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); -struct rfkill * __must_check rfkill_allocate(struct device *parent, - enum rfkill_type type); -void rfkill_free(struct rfkill *rfkill); -int __must_check rfkill_register(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); -int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state); -int rfkill_set_default(enum rfkill_type type, enum rfkill_state state); +/** + * 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_state_complement - return complementar state - * @state: state to return the complement of + * rfkill_set_global_sw_state - set global sw block default + * @type: rfkill type to set default for + * @blocked: default to set * - * Returns RFKILL_STATE_SOFT_BLOCKED if @state is RFKILL_STATE_UNBLOCKED, - * returns RFKILL_STATE_UNBLOCKED otherwise. + * 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? */ -static inline enum rfkill_state rfkill_state_complement(enum rfkill_state state) +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) { - return (state == RFKILL_STATE_UNBLOCKED) ? - RFKILL_STATE_SOFT_BLOCKED : RFKILL_STATE_UNBLOCKED; } +#endif /* RFKILL || RFKILL_MODULE */ + +#ifdef CONFIG_RFKILL_LEDS /** - * rfkill_get_led_name - Get the LED trigger name for the button's LED. + * 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. + * LED trigger failed. Use this as "default_trigger" for the LED. */ -static inline char *rfkill_get_led_name(struct rfkill *rfkill) -{ -#ifdef CONFIG_RFKILL_LEDS - return (char *)(rfkill->led_trigger.name); +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; -#endif } +static inline void +rfkill_set_led_trigger_name(struct rfkill *rfkill, const char *name) +{ +} +#endif + +#endif /* __KERNEL__ */ + #endif /* RFKILL_H */ -- cgit v1.2.3