diff options
Diffstat (limited to 'Documentation')
20 files changed, 871 insertions, 647 deletions
diff --git a/Documentation/DocBook/mac80211.tmpl b/Documentation/DocBook/mac80211.tmpl index fbeaffc1dcc..e3698666357 100644 --- a/Documentation/DocBook/mac80211.tmpl +++ b/Documentation/DocBook/mac80211.tmpl @@ -145,7 +145,6 @@ usage should require reading the full document. interface in STA mode at first! </para> !Finclude/net/mac80211.h ieee80211_if_init_conf -!Finclude/net/mac80211.h ieee80211_if_conf </chapter> <chapter id="rx-tx"> diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index ec9ef5d0d7b..7129846a278 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -438,6 +438,13 @@ Why: Superseded by tdfxfb. I2C/DDC support used to live in a separate Who: Jean Delvare <khali@linux-fr.org> Krzysztof Helt <krzysztof.h1@wp.pl> +--------------------------- + +What: CONFIG_RFKILL_INPUT +When: 2.6.33 +Why: Should be implemented in userspace, policy daemon. +Who: Johannes Berg <johannes@sipsolutions.net> + ---------------------------- What: CONFIG_X86_OLD_MCE diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt index 55c4300abfc..01539f41067 100644 --- a/Documentation/filesystems/nilfs2.txt +++ b/Documentation/filesystems/nilfs2.txt @@ -39,9 +39,8 @@ Features which NILFS2 does not support yet: - extended attributes - POSIX ACLs - quotas - - writable snapshots - - remote backup (CDP) - - data integrity + - fsck + - resize - defragmentation Mount options diff --git a/Documentation/isdn/00-INDEX b/Documentation/isdn/00-INDEX index 5a2d69989a8..f6010a53659 100644 --- a/Documentation/isdn/00-INDEX +++ b/Documentation/isdn/00-INDEX @@ -22,16 +22,11 @@ README.gigaset - info on the drivers for Siemens Gigaset ISDN adapters. README.icn - info on the ICN-ISDN-card and its driver. +>>>>>>> 93af7aca44f0e82e67bda10a0fb73d383edcc8bd:Documentation/isdn/00-INDEX README.HiSax - info on the HiSax driver which replaces the old teles. -README.hfc-pci - - info on hfc-pci based cards. -README.pcbit - - info on the PCBIT-D ISDN adapter and driver. -README.syncppp - - info on running Sync PPP over ISDN. -syncPPP.FAQ - - frequently asked questions about running PPP over ISDN. +README.audio + - info for running audio over ISDN. README.avmb1 - info on driver for AVM-B1 ISDN card. README.act2000 @@ -42,10 +37,28 @@ README.concap - info on "CONCAP" encapsulation protocol interface used for X.25. README.diversion - info on module for isdn diversion services. +README.fax + - info for using Fax over ISDN. +README.gigaset + - info on the drivers for Siemens Gigaset ISDN adapters +README.hfc-pci + - info on hfc-pci based cards. +README.hysdn + - info on driver for Hypercope active HYSDN cards +README.icn + - info on the ICN-ISDN-card and its driver. +README.mISDN + - info on the Modular ISDN subsystem (mISDN) +README.pcbit + - info on the PCBIT-D ISDN adapter and driver. README.sc - info on driver for Spellcaster cards. +README.syncppp + - info on running Sync PPP over ISDN. README.x25 - info for running X.25 over ISDN. +syncPPP.FAQ + - frequently asked questions about running PPP over ISDN. README.hysdn - info on driver for Hypercope active HYSDN cards README.mISDN diff --git a/Documentation/isdn/INTERFACE.CAPI b/Documentation/isdn/INTERFACE.CAPI index 786d619b36e..686e107923e 100644 --- a/Documentation/isdn/INTERFACE.CAPI +++ b/Documentation/isdn/INTERFACE.CAPI @@ -45,7 +45,7 @@ From then on, Kernel CAPI may call the registered callback functions for the device. If the device becomes unusable for any reason (shutdown, disconnect ...), the -driver has to call capi_ctr_reseted(). This will prevent further calls to the +driver has to call capi_ctr_down(). This will prevent further calls to the callback functions by Kernel CAPI. @@ -114,20 +114,36 @@ char *driver_name int (*load_firmware)(struct capi_ctr *ctrlr, capiloaddata *ldata) (optional) pointer to a callback function for sending firmware and configuration data to the device + Return value: 0 on success, error code on error + Called in process context. void (*reset_ctr)(struct capi_ctr *ctrlr) - pointer to a callback function for performing a reset on the device, - releasing all registered applications + (optional) pointer to a callback function for performing a reset on + the device, releasing all registered applications + Called in process context. void (*register_appl)(struct capi_ctr *ctrlr, u16 applid, capi_register_params *rparam) void (*release_appl)(struct capi_ctr *ctrlr, u16 applid) pointers to callback functions for registration and deregistration of applications with the device + Calls to these functions are serialized by Kernel CAPI so that only + one call to any of them is active at any time. u16 (*send_message)(struct capi_ctr *ctrlr, struct sk_buff *skb) pointer to a callback function for sending a CAPI message to the device + Return value: CAPI error code + If the method returns 0 (CAPI_NOERROR) the driver has taken ownership + of the skb and the caller may no longer access it. If it returns a + non-zero (error) value then ownership of the skb returns to the caller + who may reuse or free it. + The return value should only be used to signal problems with respect + to accepting or queueing the message. Errors occurring during the + actual processing of the message should be signaled with an + appropriate reply message. + Calls to this function are not serialized by Kernel CAPI, ie. it must + be prepared to be re-entered. char *(*procinfo)(struct capi_ctr *ctrlr) pointer to a callback function returning the entry for the device in @@ -138,6 +154,8 @@ read_proc_t *ctr_read_proc system entry, /proc/capi/controllers/<n>; will be called with a pointer to the device's capi_ctr structure as the last (data) argument +Note: Callback functions are never called in interrupt context. + - to be filled in before calling capi_ctr_ready(): u8 manu[CAPI_MANUFACTURER_LEN] @@ -153,6 +171,45 @@ u8 serial[CAPI_SERIAL_LEN] value to return for CAPI_GET_SERIAL +4.3 The _cmsg Structure + +(declared in <linux/isdn/capiutil.h>) + +The _cmsg structure stores the contents of a CAPI 2.0 message in an easily +accessible form. It contains members for all possible CAPI 2.0 parameters, of +which only those appearing in the message type currently being processed are +actually used. Unused members should be set to zero. + +Members are named after the CAPI 2.0 standard names of the parameters they +represent. See <linux/isdn/capiutil.h> for the exact spelling. Member data +types are: + +u8 for CAPI parameters of type 'byte' + +u16 for CAPI parameters of type 'word' + +u32 for CAPI parameters of type 'dword' + +_cstruct for CAPI parameters of type 'struct' not containing any + variably-sized (struct) subparameters (eg. 'Called Party Number') + The member is a pointer to a buffer containing the parameter in + CAPI encoding (length + content). It may also be NULL, which will + be taken to represent an empty (zero length) parameter. + +_cmstruct for CAPI parameters of type 'struct' containing 'struct' + subparameters ('Additional Info' and 'B Protocol') + The representation is a single byte containing one of the values: + CAPI_DEFAULT: the parameter is empty + CAPI_COMPOSE: the values of the subparameters are stored + individually in the corresponding _cmsg structure members + +Functions capi_cmsg2message() and capi_message2cmsg() are provided to convert +messages between their transport encoding described in the CAPI 2.0 standard +and their _cmsg structure representation. Note that capi_cmsg2message() does +not know or check the size of its destination buffer. The caller must make +sure it is big enough to accomodate the resulting CAPI message. + + 5. Lower Layer Interface Functions (declared in <linux/isdn/capilli.h>) @@ -166,7 +223,7 @@ int detach_capi_ctr(struct capi_ctr *ctrlr) register/unregister a device (controller) with Kernel CAPI void capi_ctr_ready(struct capi_ctr *ctrlr) -void capi_ctr_reseted(struct capi_ctr *ctrlr) +void capi_ctr_down(struct capi_ctr *ctrlr) signal controller ready/not ready void capi_ctr_suspend_output(struct capi_ctr *ctrlr) @@ -211,3 +268,32 @@ CAPIMSG_CONTROL(m) CAPIMSG_SETCONTROL(m, contr) Controller/PLCI/NCCI (u32) CAPIMSG_DATALEN(m) CAPIMSG_SETDATALEN(m, len) Data Length (u16) + +Library functions for working with _cmsg structures +(from <linux/isdn/capiutil.h>): + +unsigned capi_cmsg2message(_cmsg *cmsg, u8 *msg) + Assembles a CAPI 2.0 message from the parameters in *cmsg, storing the + result in *msg. + +unsigned capi_message2cmsg(_cmsg *cmsg, u8 *msg) + Disassembles the CAPI 2.0 message in *msg, storing the parameters in + *cmsg. + +unsigned capi_cmsg_header(_cmsg *cmsg, u16 ApplId, u8 Command, u8 Subcommand, + u16 Messagenumber, u32 Controller) + Fills the header part and address field of the _cmsg structure *cmsg + with the given values, zeroing the remainder of the structure so only + parameters with non-default values need to be changed before sending + the message. + +void capi_cmsg_answer(_cmsg *cmsg) + Sets the low bit of the Subcommand field in *cmsg, thereby converting + _REQ to _CONF and _IND to _RESP. + +char *capi_cmd2str(u8 Command, u8 Subcommand) + Returns the CAPI 2.0 message name corresponding to the given command + and subcommand values, as a static ASCII string. The return value may + be NULL if the command/subcommand is not one of those defined in the + CAPI 2.0 standard. + diff --git a/Documentation/isdn/README.gigaset b/Documentation/isdn/README.gigaset index 02c0e9341dd..f9963103ae3 100644 --- a/Documentation/isdn/README.gigaset +++ b/Documentation/isdn/README.gigaset @@ -149,10 +149,8 @@ GigaSet 307x Device Driver configuration files and chat scripts in the gigaset-VERSION/ppp directory in the driver packages from http://sourceforge.net/projects/gigaset307x/. Please note that the USB drivers are not able to change the state of the - control lines (the M105 driver can be configured to use some undocumented - control requests, if you really need the control lines, though). This means - you must use "Stupid Mode" if you are using wvdial or you should use the - nocrtscts option of pppd. + control lines. This means you must use "Stupid Mode" if you are using + wvdial or you should use the nocrtscts option of pppd. You must also assure that the ppp_async module is loaded with the parameter flag_time=0. You can do this e.g. by adding a line like @@ -190,20 +188,19 @@ GigaSet 307x Device Driver You can also use /sys/class/tty/ttyGxy/cidmode for changing the CID mode setting (ttyGxy is ttyGU0 or ttyGB0). -2.6. M105 Undocumented USB Requests - ------------------------------ - - The Gigaset M105 USB data box understands a couple of useful, but - undocumented USB commands. These requests are not used in normal - operation (for wireless access to the base), but are needed for access - to the M105's own configuration mode (registration to the base, baudrate - and line format settings, device status queries) via the gigacontr - utility. Their use is controlled by the kernel configuration option - "Support for undocumented USB requests" (CONFIG_GIGASET_UNDOCREQ). If you - encounter error code -ENOTTY when trying to use some features of the - M105, try setting that option to "y" via 'make {x,menu}config' and - recompiling the driver. - +2.6. Unregistered Wireless Devices (M101/M105) + ----------------------------------------- + The main purpose of the ser_gigaset and usb_gigaset drivers is to allow + the M101 and M105 wireless devices to be used as ISDN devices for ISDN + connections through a Gigaset base. Therefore they assume that the device + is registered to a DECT base. + + If the M101/M105 device is not registered to a base, initialization of + the device fails, and a corresponding error message is logged by the + driver. In that situation, a restricted set of functions is available + which includes, in particular, those necessary for registering the device + to a base or for switching it between Fixed Part and Portable Part + modes. 3. Troubleshooting --------------- @@ -234,11 +231,12 @@ GigaSet 307x Device Driver Select Unimodem mode for all DECT data adapters. (see section 2.4.) Problem: - You want to configure your USB DECT data adapter (M105) but gigacontr - reports an error: "/dev/ttyGU0: Inappropriate ioctl for device". + Messages like this: + usb_gigaset 3-2:1.0: Could not initialize the device. + appear in your syslog. Solution: - Recompile the usb_gigaset driver with the kernel configuration option - CONFIG_GIGASET_UNDOCREQ set to 'y'. (see section 2.6.) + Check whether your M10x wireless device is correctly registered to the + Gigaset base. (see section 2.6.) 3.2. Telling the driver to provide more information ---------------------------------------------- diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4b765b7ded9..4426e0b81a1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -491,6 +491,13 @@ and is between 256 and 4096 characters. It is defined in the file Also note the kernel might malfunction if you disable some critical bits. + cmo_free_hint= [PPC] Format: { yes | no } + Specify whether pages are marked as being inactive + when they are freed. This is used in CMO environments + to determine OS memory pressure for page stealing by + a hypervisor. + Default: yes + code_bytes [X86] How many bytes of object code to print in an oops report. Range: 0 - 8192 diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt index 463d9e029ef..cd79735013f 100644 --- a/Documentation/networking/can.txt +++ b/Documentation/networking/can.txt @@ -36,10 +36,15 @@ This file contains 6.2 local loopback of sent frames 6.3 CAN controller hardware filters 6.4 The virtual CAN driver (vcan) - 6.5 currently supported CAN hardware - 6.6 todo + 6.5 The CAN network device driver interface + 6.5.1 Netlink interface to set/get devices properties + 6.5.2 Setting the CAN bit-timing + 6.5.3 Starting and stopping the CAN network device + 6.6 supported CAN hardware - 7 Credits + 7 Socket CAN resources + + 8 Credits ============================================================================ @@ -234,6 +239,8 @@ solution for a couple of reasons: the user application using the common CAN filter mechanisms. Inside this filter definition the (interested) type of errors may be selected. The reception of error frames is disabled by default. + The format of the CAN error frame is briefly decribed in the Linux + header file "include/linux/can/error.h". 4. How to use Socket CAN ------------------------ @@ -605,61 +612,213 @@ solution for a couple of reasons: removal of vcan network devices can be managed with the ip(8) tool: - Create a virtual CAN network interface: - ip link add type vcan + $ ip link add type vcan - Create a virtual CAN network interface with a specific name 'vcan42': - ip link add dev vcan42 type vcan + $ ip link add dev vcan42 type vcan - Remove a (virtual CAN) network interface 'vcan42': - ip link del vcan42 - - The tool 'vcan' from the SocketCAN SVN repository on BerliOS is obsolete. - - Virtual CAN network device creation in older Kernels: - In Linux Kernel versions < 2.6.24 the vcan driver creates 4 vcan - netdevices at module load time by default. This value can be changed - with the module parameter 'numdev'. E.g. 'modprobe vcan numdev=8' - - 6.5 currently supported CAN hardware + $ ip link del vcan42 + + 6.5 The CAN network device driver interface + + The CAN network device driver interface provides a generic interface + to setup, configure and monitor CAN network devices. The user can then + configure the CAN device, like setting the bit-timing parameters, via + the netlink interface using the program "ip" from the "IPROUTE2" + utility suite. The following chapter describes briefly how to use it. + Furthermore, the interface uses a common data structure and exports a + set of common functions, which all real CAN network device drivers + should use. Please have a look to the SJA1000 or MSCAN driver to + understand how to use them. The name of the module is can-dev.ko. + + 6.5.1 Netlink interface to set/get devices properties + + The CAN device must be configured via netlink interface. The supported + netlink message types are defined and briefly described in + "include/linux/can/netlink.h". CAN link support for the program "ip" + of the IPROUTE2 utility suite is avaiable and it can be used as shown + below: + + - Setting CAN device properties: + + $ ip link set can0 type can help + Usage: ip link set DEVICE type can + [ bitrate BITRATE [ sample-point SAMPLE-POINT] ] | + [ tq TQ prop-seg PROP_SEG phase-seg1 PHASE-SEG1 + phase-seg2 PHASE-SEG2 [ sjw SJW ] ] + + [ loopback { on | off } ] + [ listen-only { on | off } ] + [ triple-sampling { on | off } ] + + [ restart-ms TIME-MS ] + [ restart ] + + Where: BITRATE := { 1..1000000 } + SAMPLE-POINT := { 0.000..0.999 } + TQ := { NUMBER } + PROP-SEG := { 1..8 } + PHASE-SEG1 := { 1..8 } + PHASE-SEG2 := { 1..8 } + SJW := { 1..4 } + RESTART-MS := { 0 | NUMBER } + + - Display CAN device details and statistics: + + $ ip -details -statistics link show can0 + 2: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UP qlen 10 + link/can + can <TRIPLE-SAMPLING> state ERROR-ACTIVE restart-ms 100 + bitrate 125000 sample_point 0.875 + tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1 + sja1000: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1 + clock 8000000 + re-started bus-errors arbit-lost error-warn error-pass bus-off + 41 17457 0 41 42 41 + RX: bytes packets errors dropped overrun mcast + 140859 17608 17457 0 0 0 + TX: bytes packets errors dropped carrier collsns + 861 112 0 41 0 0 + + More info to the above output: + + "<TRIPLE-SAMPLING>" + Shows the list of selected CAN controller modes: LOOPBACK, + LISTEN-ONLY, or TRIPLE-SAMPLING. + + "state ERROR-ACTIVE" + The current state of the CAN controller: "ERROR-ACTIVE", + "ERROR-WARNING", "ERROR-PASSIVE", "BUS-OFF" or "STOPPED" + + "restart-ms 100" + Automatic restart delay time. If set to a non-zero value, a + restart of the CAN controller will be triggered automatically + in case of a bus-off condition after the specified delay time + in milliseconds. By default it's off. + + "bitrate 125000 sample_point 0.875" + Shows the real bit-rate in bits/sec and the sample-point in the + range 0.000..0.999. If the calculation of bit-timing parameters + is enabled in the kernel (CONFIG_CAN_CALC_BITTIMING=y), the + bit-timing can be defined by setting the "bitrate" argument. + Optionally the "sample-point" can be specified. By default it's + 0.000 assuming CIA-recommended sample-points. + + "tq 125 prop-seg 6 phase-seg1 7 phase-seg2 2 sjw 1" + Shows the time quanta in ns, propagation segment, phase buffer + segment 1 and 2 and the synchronisation jump width in units of + tq. They allow to define the CAN bit-timing in a hardware + independent format as proposed by the Bosch CAN 2.0 spec (see + chapter 8 of http://www.semiconductors.bosch.de/pdf/can2spec.pdf). + + "sja1000: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1 + clock 8000000" + Shows the bit-timing constants of the CAN controller, here the + "sja1000". The minimum and maximum values of the time segment 1 + and 2, the synchronisation jump width in units of tq, the + bitrate pre-scaler and the CAN system clock frequency in Hz. + These constants could be used for user-defined (non-standard) + bit-timing calculation algorithms in user-space. + + "re-started bus-errors arbit-lost error-warn error-pass bus-off" + Shows the number of restarts, bus and arbitration lost errors, + and the state changes to the error-warning, error-passive and + bus-off state. RX overrun errors are listed in the "overrun" + field of the standard network statistics. + + 6.5.2 Setting the CAN bit-timing + + The CAN bit-timing parameters can always be defined in a hardware + independent format as proposed in the Bosch CAN 2.0 specification + specifying the arguments "tq", "prop_seg", "phase_seg1", "phase_seg2" + and "sjw": + + $ ip link set canX type can tq 125 prop-seg 6 \ + phase-seg1 7 phase-seg2 2 sjw 1 + + If the kernel option CONFIG_CAN_CALC_BITTIMING is enabled, CIA + recommended CAN bit-timing parameters will be calculated if the bit- + rate is specified with the argument "bitrate": + + $ ip link set canX type can bitrate 125000 + + Note that this works fine for the most common CAN controllers with + standard bit-rates but may *fail* for exotic bit-rates or CAN system + clock frequencies. Disabling CONFIG_CAN_CALC_BITTIMING saves some + space and allows user-space tools to solely determine and set the + bit-timing parameters. The CAN controller specific bit-timing + constants can be used for that purpose. They are listed by the + following command: + + $ ip -details link show can0 + ... + sja1000: clock 8000000 tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1 + + 6.5.3 Starting and stopping the CAN network device + + A CAN network device is started or stopped as usual with the command + "ifconfig canX up/down" or "ip link set canX up/down". Be aware that + you *must* define proper bit-timing parameters for real CAN devices + before you can start it to avoid error-prone default settings: + + $ ip link set canX up type can bitrate 125000 + + A device may enter the "bus-off" state if too much errors occurred on + the CAN bus. Then no more messages are received or sent. An automatic + bus-off recovery can be enabled by setting the "restart-ms" to a + non-zero value, e.g.: + + $ ip link set canX type can restart-ms 100 + + Alternatively, the application may realize the "bus-off" condition + by monitoring CAN error frames and do a restart when appropriate with + the command: + + $ ip link set canX type can restart + + Note that a restart will also create a CAN error frame (see also + chapter 3.4). - On the project website http://developer.berlios.de/projects/socketcan - there are different drivers available: + 6.6 Supported CAN hardware - vcan: Virtual CAN interface driver (if no real hardware is available) - sja1000: Philips SJA1000 CAN controller (recommended) - i82527: Intel i82527 CAN controller - mscan: Motorola/Freescale CAN controller (e.g. inside SOC MPC5200) - ccan: CCAN controller core (e.g. inside SOC h7202) - slcan: For a bunch of CAN adaptors that are attached via a - serial line ASCII protocol (for serial / USB adaptors) + Please check the "Kconfig" file in "drivers/net/can" to get an actual + list of the support CAN hardware. On the Socket CAN project website + (see chapter 7) there might be further drivers available, also for + older kernel versions. - Additionally the different CAN adaptors (ISA/PCI/PCMCIA/USB/Parport) - from PEAK Systemtechnik support the CAN netdevice driver model - since Linux driver v6.0: http://www.peak-system.com/linux/index.htm +7. Socket CAN resources +----------------------- - Please check the Mailing Lists on the berlios OSS project website. + You can find further resources for Socket CAN like user space tools, + support for old kernel versions, more drivers, mailing lists, etc. + at the BerliOS OSS project website for Socket CAN: - 6.6 todo + http://developer.berlios.de/projects/socketcan - The configuration interface for CAN network drivers is still an open - issue that has not been finalized in the socketcan project. Also the - idea of having a library module (candev.ko) that holds functions - that are needed by all CAN netdevices is not ready to ship. - Your contribution is welcome. + If you have questions, bug fixes, etc., don't hesitate to post them to + the Socketcan-Users mailing list. But please search the archives first. -7. Credits +8. Credits ---------- - Oliver Hartkopp (PF_CAN core, filters, drivers, bcm) + Oliver Hartkopp (PF_CAN core, filters, drivers, bcm, SJA1000 driver) Urs Thuermann (PF_CAN core, kernel integration, socket interfaces, raw, vcan) Jan Kizka (RT-SocketCAN core, Socket-API reconciliation) - Wolfgang Grandegger (RT-SocketCAN core & drivers, Raw Socket-API reviews) + Wolfgang Grandegger (RT-SocketCAN core & drivers, Raw Socket-API reviews, + CAN device driver interface, MSCAN driver) Robert Schwebel (design reviews, PTXdist integration) Marc Kleine-Budde (design reviews, Kernel 2.6 cleanups, drivers) Benedikt Spranger (reviews) Thomas Gleixner (LKML reviews, coding style, posting hints) - Andrey Volkov (kernel subtree structure, ioctls, mscan driver) + Andrey Volkov (kernel subtree structure, ioctls, MSCAN driver) Matthias Brukner (first SJA1000 CAN netdevice implementation Q2/2003) Klaus Hitschler (PEAK driver integration) Uwe Koppe (CAN netdevices with PF_PACKET approach) Michael Schulze (driver layer loopback requirement, RT CAN drivers review) + Pavel Pisa (Bit-timing calculation) + Sascha Hauer (SJA1000 platform driver) + Sebastian Haas (SJA1000 EMS PCI driver) + Markus Plessing (SJA1000 EMS PCI driver) + Per Dalen (SJA1000 Kvaser PCI driver) + Sam Ravnborg (reviews, coding style, kbuild help) diff --git a/Documentation/networking/ieee802154.txt b/Documentation/networking/ieee802154.txt new file mode 100644 index 00000000000..a0280ad2edc --- /dev/null +++ b/Documentation/networking/ieee802154.txt @@ -0,0 +1,76 @@ + + Linux IEEE 802.15.4 implementation + + +Introduction +============ + +The Linux-ZigBee project goal is to provide complete implementation +of IEEE 802.15.4 / ZigBee / 6LoWPAN protocols. IEEE 802.15.4 is a stack +of protocols for organizing Low-Rate Wireless Personal Area Networks. + +Currently only IEEE 802.15.4 layer is implemented. We have choosen +to use plain Berkeley socket API, the generic Linux networking stack +to transfer IEEE 802.15.4 messages and a special protocol over genetlink +for configuration/management + + +Socket API +========== + +int sd = socket(PF_IEEE802154, SOCK_DGRAM, 0); +..... + +The address family, socket addresses etc. are defined in the +include/net/ieee802154/af_ieee802154.h header or in the special header +in our userspace package (see either linux-zigbee sourceforge download page +or git tree at git://linux-zigbee.git.sourceforge.net/gitroot/linux-zigbee). + +One can use SOCK_RAW for passing raw data towards device xmit function. YMMV. + + +MLME - MAC Level Management +============================ + +Most of IEEE 802.15.4 MLME interfaces are directly mapped on netlink commands. +See the include/net/ieee802154/nl802154.h header. Our userspace tools package +(see above) provides CLI configuration utility for radio interfaces and simple +coordinator for IEEE 802.15.4 networks as an example users of MLME protocol. + + +Kernel side +============= + +Like with WiFi, there are several types of devices implementing IEEE 802.15.4. +1) 'HardMAC'. The MAC layer is implemented in the device itself, the device + exports MLME and data API. +2) 'SoftMAC' or just radio. These types of devices are just radio transceivers + possibly with some kinds of acceleration like automatic CRC computation and + comparation, automagic ACK handling, address matching, etc. + +Those types of devices require different approach to be hooked into Linux kernel. + + +HardMAC +======= + +See the header include/net/ieee802154/netdevice.h. You have to implement Linux +net_device, with .type = ARPHRD_IEEE802154. Data is exchanged with socket family +code via plain sk_buffs. The control block of sk_buffs will contain additional +info as described in the struct ieee802154_mac_cb. + +To hook the MLME interface you have to populate the ml_priv field of your +net_device with a pointer to struct ieee802154_mlme_ops instance. All fields are +required. + +We provide an example of simple HardMAC driver at drivers/ieee802154/fakehard.c + + +SoftMAC +======= + +We are going to provide intermediate layer impelementing IEEE 802.15.4 MAC +in software. This is currently WIP. + +See header include/net/ieee802154/mac802154.h and several drivers in +drivers/ieee802154/ diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index b121c5db707..8be76235fe6 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -168,7 +168,16 @@ tcp_dsack - BOOLEAN Allows TCP to send "duplicate" SACKs. tcp_ecn - BOOLEAN - Enable Explicit Congestion Notification in TCP. + Enable Explicit Congestion Notification (ECN) in TCP. ECN is only + used when both ends of the TCP flow support it. It is useful to + avoid losses due to congestion (when the bottleneck router supports + ECN). + Possible values are: + 0 disable ECN + 1 ECN enabled + 2 Only server-side ECN enabled. If the other end does + not support ECN, behavior is like with ECN disabled. + Default: 2 tcp_fack - BOOLEAN Enable FACK congestion avoidance and fast retransmission. @@ -1048,6 +1057,13 @@ disable_ipv6 - BOOLEAN address. Default: FALSE (enable IPv6 operation) + When this value is changed from 1 to 0 (IPv6 is being enabled), + it will dynamically create a link-local address on the given + interface and start Duplicate Address Detection, if necessary. + + When this value is changed from 0 to 1 (IPv6 is being disabled), + it will dynamically delete all address on the given interface. + accept_dad - INTEGER Whether to accept DAD (Duplicate Address Detection). 0: Disable DAD diff --git a/Documentation/networking/ipv6.txt b/Documentation/networking/ipv6.txt index 268e5c103dd..9fd7e21296c 100644 --- a/Documentation/networking/ipv6.txt +++ b/Documentation/networking/ipv6.txt @@ -33,3 +33,40 @@ disable A reboot is required to enable IPv6. +autoconf + + Specifies whether to enable IPv6 address autoconfiguration + on all interfaces. This might be used when one does not wish + for addresses to be automatically generated from prefixes + received in Router Advertisements. + + The possible values and their effects are: + + 0 + IPv6 address autoconfiguration is disabled on all interfaces. + + Only the IPv6 loopback address (::1) and link-local addresses + will be added to interfaces. + + 1 + IPv6 address autoconfiguration is enabled on all interfaces. + + This is the default value. + +disable_ipv6 + + Specifies whether to disable IPv6 on all interfaces. + This might be used when no IPv6 addresses are desired. + + The possible values and their effects are: + + 0 + IPv6 is enabled on all interfaces. + + This is the default value. + + 1 + IPv6 is disabled on all interfaces. + + No IPv6 addresses will be added to interfaces. + diff --git a/Documentation/networking/mac80211-injection.txt b/Documentation/networking/mac80211-injection.txt index 84906ef3ed6..b30e81ad530 100644 --- a/Documentation/networking/mac80211-injection.txt +++ b/Documentation/networking/mac80211-injection.txt @@ -12,38 +12,22 @@ following format: The radiotap format is discussed in ./Documentation/networking/radiotap-headers.txt. -Despite 13 radiotap argument types are currently defined, most only make sense +Despite many radiotap parameters being currently defined, most only make sense to appear on received packets. The following information is parsed from the radiotap headers and used to control injection: - * IEEE80211_RADIOTAP_RATE - - rate in 500kbps units, automatic if invalid or not present - - - * IEEE80211_RADIOTAP_ANTENNA - - antenna to use, automatic if not present - - - * IEEE80211_RADIOTAP_DBM_TX_POWER - - transmit power in dBm, automatic if not present - - * IEEE80211_RADIOTAP_FLAGS IEEE80211_RADIOTAP_F_FCS: FCS will be removed and recalculated IEEE80211_RADIOTAP_F_WEP: frame will be encrypted if key available IEEE80211_RADIOTAP_F_FRAG: frame will be fragmented if longer than the - current fragmentation threshold. Note that - this flag is only reliable when software - fragmentation is enabled) + current fragmentation threshold. + The injection code can also skip all other currently defined radiotap fields facilitating replay of captured radiotap headers directly. -Here is an example valid radiotap header defining these three parameters +Here is an example valid radiotap header defining some parameters 0x00, 0x00, // <-- radiotap version 0x0b, 0x00, // <- radiotap header length @@ -72,8 +56,8 @@ interface), along the following lines: ... r = pcap_inject(ppcap, u8aSendBuffer, nLength); -You can also find sources for a complete inject test applet here: +You can also find a link to a complete inject application here: -http://penumbra.warmcat.com/_twk/tiki-index.php?page=packetspammer +http://wireless.kernel.org/en/users/Documentation/packetspammer Andy Green <andy@warmcat.com> diff --git a/Documentation/networking/operstates.txt b/Documentation/networking/operstates.txt index c9074f9b78b..1a77a3cfae5 100644 --- a/Documentation/networking/operstates.txt +++ b/Documentation/networking/operstates.txt @@ -38,9 +38,6 @@ ifinfomsg::if_flags & IFF_LOWER_UP: ifinfomsg::if_flags & IFF_DORMANT: Driver has signaled netif_dormant_on() -These interface flags can also be queried without netlink using the -SIOCGIFFLAGS ioctl. - TLV IFLA_OPERSTATE contains RFC2863 state of the interface in numeric representation: diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt index 07c53d59603..a22fd85e379 100644 --- a/Documentation/networking/packet_mmap.txt +++ b/Documentation/networking/packet_mmap.txt @@ -4,16 +4,18 @@ This file documents the CONFIG_PACKET_MMAP option available with the PACKET socket interface on 2.4 and 2.6 kernels. This type of sockets is used for -capture network traffic with utilities like tcpdump or any other that uses -the libpcap library. - -You can find the latest version of this document at +capture network traffic with utilities like tcpdump or any other that needs +raw access to network interface. +You can find the latest version of this document at: http://pusa.uv.es/~ulisses/packet_mmap/ -Please send me your comments to +Howto can be found at: + http://wiki.gnu-log.net (packet_mmap) +Please send your comments to Ulisses Alonso Camaró <uaca@i.hate.spam.alumni.uv.es> + Johann Baudy <johann.baudy@gnu-log.net> ------------------------------------------------------------------------------- + Why use PACKET_MMAP @@ -25,19 +27,24 @@ to capture each packet, it requires two if you want to get packet's timestamp (like libpcap always does). In the other hand PACKET_MMAP is very efficient. PACKET_MMAP provides a size -configurable circular buffer mapped in user space. This way reading packets just -needs to wait for them, most of the time there is no need to issue a single -system call. By using a shared buffer between the kernel and the user -also has the benefit of minimizing packet copies. - -It's fine to use PACKET_MMAP to improve the performance of the capture process, -but it isn't everything. At least, if you are capturing at high speeds (this -is relative to the cpu speed), you should check if the device driver of your -network interface card supports some sort of interrupt load mitigation or -(even better) if it supports NAPI, also make sure it is enabled. +configurable circular buffer mapped in user space that can be used to either +send or receive packets. This way reading packets just needs to wait for them, +most of the time there is no need to issue a single system call. Concerning +transmission, multiple packets can be sent through one system call to get the +highest bandwidth. +By using a shared buffer between the kernel and the user also has the benefit +of minimizing packet copies. + +It's fine to use PACKET_MMAP to improve the performance of the capture and +transmission process, but it isn't everything. At least, if you are capturing +at high speeds (this is relative to the cpu speed), you should check if the +device driver of your network interface card supports some sort of interrupt +load mitigation or (even better) if it supports NAPI, also make sure it is +enabled. For transmission, check the MTU (Maximum Transmission Unit) used and +supported by devices of your network. -------------------------------------------------------------------------------- -+ How to use CONFIG_PACKET_MMAP ++ How to use CONFIG_PACKET_MMAP to improve capture process -------------------------------------------------------------------------------- From the user standpoint, you should use the higher level libpcap library, which @@ -57,7 +64,7 @@ the low level details or want to improve libpcap by including PACKET_MMAP support. -------------------------------------------------------------------------------- -+ How to use CONFIG_PACKET_MMAP directly ++ How to use CONFIG_PACKET_MMAP directly to improve capture process -------------------------------------------------------------------------------- From the system calls stand point, the use of PACKET_MMAP involves @@ -66,6 +73,7 @@ the following process: [setup] socket() -------> creation of the capture socket setsockopt() ---> allocation of the circular buffer (ring) + option: PACKET_RX_RING mmap() ---------> mapping of the allocated buffer to the user process @@ -97,13 +105,75 @@ also the mapping of the circular buffer in the user process and the use of this buffer. -------------------------------------------------------------------------------- ++ How to use CONFIG_PACKET_MMAP directly to improve transmission process +-------------------------------------------------------------------------------- +Transmission process is similar to capture as shown below. + +[setup] socket() -------> creation of the transmission socket + setsockopt() ---> allocation of the circular buffer (ring) + option: PACKET_TX_RING + bind() ---------> bind transmission socket with a network interface + mmap() ---------> mapping of the allocated buffer to the + user process + +[transmission] poll() ---------> wait for free packets (optional) + send() ---------> send all packets that are set as ready in + the ring + The flag MSG_DONTWAIT can be used to return + before end of transfer. + +[shutdown] close() --------> destruction of the transmission socket and + deallocation of all associated resources. + +Binding the socket to your network interface is mandatory (with zero copy) to +know the header size of frames used in the circular buffer. + +As capture, each frame contains two parts: + + -------------------- +| struct tpacket_hdr | Header. It contains the status of +| | of this frame +|--------------------| +| data buffer | +. . Data that will be sent over the network interface. +. . + -------------------- + + bind() associates the socket to your network interface thanks to + sll_ifindex parameter of struct sockaddr_ll. + + Initialization example: + + struct sockaddr_ll my_addr; + struct ifreq s_ifr; + ... + + strncpy (s_ifr.ifr_name, "eth0", sizeof(s_ifr.ifr_name)); + + /* get interface index of eth0 */ + ioctl(this->socket, SIOCGIFINDEX, &s_ifr); + + /* fill sockaddr_ll struct to prepare binding */ + my_addr.sll_family = AF_PACKET; + my_addr.sll_protocol = ETH_P_ALL; + my_addr.sll_ifindex = s_ifr.ifr_ifindex; + + /* bind socket to eth0 */ + bind(this->socket, (struct sockaddr *)&my_addr, sizeof(struct sockaddr_ll)); + + A complete tutorial is available at: http://wiki.gnu-log.net/ + +-------------------------------------------------------------------------------- + PACKET_MMAP settings -------------------------------------------------------------------------------- To setup PACKET_MMAP from user level code is done with a call like + - Capture process setsockopt(fd, SOL_PACKET, PACKET_RX_RING, (void *) &req, sizeof(req)) + - Transmission process + setsockopt(fd, SOL_PACKET, PACKET_TX_RING, (void *) &req, sizeof(req)) The most significant argument in the previous call is the req parameter, this parameter must to have the following structure: @@ -117,11 +187,11 @@ this parameter must to have the following structure: }; This structure is defined in /usr/include/linux/if_packet.h and establishes a -circular buffer (ring) of unswappable memory mapped in the capture process. +circular buffer (ring) of unswappable memory. Being mapped in the capture process allows reading the captured frames and related meta-information like timestamps without requiring a system call. -Captured frames are grouped in blocks. Each block is a physically contiguous +Frames are grouped in blocks. Each block is a physically contiguous region of memory and holds tp_block_size/tp_frame_size frames. The total number of blocks is tp_block_nr. Note that tp_frame_nr is a redundant parameter because @@ -336,6 +406,7 @@ struct tpacket_hdr). If this field is 0 means that the frame is ready to be used for the kernel, If not, there is a frame the user can read and the following flags apply: ++++ Capture process: from include/linux/if_packet.h #define TP_STATUS_COPY 2 @@ -391,6 +462,37 @@ packets are in the ring: It doesn't incur in a race condition to first check the status value and then poll for frames. + +++ Transmission process +Those defines are also used for transmission: + + #define TP_STATUS_AVAILABLE 0 // Frame is available + #define TP_STATUS_SEND_REQUEST 1 // Frame will be sent on next send() + #define TP_STATUS_SENDING 2 // Frame is currently in transmission + #define TP_STATUS_WRONG_FORMAT 4 // Frame format is not correct + +First, the kernel initializes all frames to TP_STATUS_AVAILABLE. To send a +packet, the user fills a data buffer of an available frame, sets tp_len to +current data buffer size and sets its status field to TP_STATUS_SEND_REQUEST. +This can be done on multiple frames. Once the user is ready to transmit, it +calls send(). Then all buffers with status equal to TP_STATUS_SEND_REQUEST are +forwarded to the network device. The kernel updates each status of sent +frames with TP_STATUS_SENDING until the end of transfer. +At the end of each transfer, buffer status returns to TP_STATUS_AVAILABLE. + + header->tp_len = in_i_size; + header->tp_status = TP_STATUS_SEND_REQUEST; + retval = send(this->socket, NULL, 0, 0); + +The user can also use poll() to check if a buffer is available: +(status == TP_STATUS_SENDING) + + struct pollfd pfd; + pfd.fd = fd; + pfd.revents = 0; + pfd.events = POLLOUT; + retval = poll(&pfd, 1, timeout); + -------------------------------------------------------------------------------- + THANKS -------------------------------------------------------------------------------- diff --git a/Documentation/powerpc/dts-bindings/can/sja1000.txt b/Documentation/powerpc/dts-bindings/can/sja1000.txt new file mode 100644 index 00000000000..d6d209ded93 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/can/sja1000.txt @@ -0,0 +1,53 @@ +Memory mapped SJA1000 CAN controller from NXP (formerly Philips) + +Required properties: + +- compatible : should be "nxp,sja1000". + +- reg : should specify the chip select, address offset and size required + to map the registers of the SJA1000. The size is usually 0x80. + +- interrupts: property with a value describing the interrupt source + (number and sensitivity) required for the SJA1000. + +Optional properties: + +- nxp,external-clock-frequency : Frequency of the external oscillator + clock in Hz. Note that the internal clock frequency used by the + SJA1000 is half of that value. If not specified, a default value + of 16000000 (16 MHz) is used. + +- nxp,tx-output-mode : operation mode of the TX output control logic: + <0x0> : bi-phase output mode + <0x1> : normal output mode (default) + <0x2> : test output mode + <0x3> : clock output mode + +- nxp,tx-output-config : TX output pin configuration: + <0x01> : TX0 invert + <0x02> : TX0 pull-down (default) + <0x04> : TX0 pull-up + <0x06> : TX0 push-pull + <0x08> : TX1 invert + <0x10> : TX1 pull-down + <0x20> : TX1 pull-up + <0x30> : TX1 push-pull + +- nxp,clock-out-frequency : clock frequency in Hz on the CLKOUT pin. + If not specified or if the specified value is 0, the CLKOUT pin + will be disabled. + +- nxp,no-comparator-bypass : Allows to disable the CAN input comperator. + +For futher information, please have a look to the SJA1000 data sheet. + +Examples: + +can@3,100 { + compatible = "nxp,sja1000"; + reg = <3 0x100 0x80>; + interrupts = <2 0>; + interrupt-parent = <&mpic>; + nxp,external-clock-frequency = <16000000>; +}; + diff --git a/Documentation/powerpc/dts-bindings/ecm.txt b/Documentation/powerpc/dts-bindings/ecm.txt new file mode 100644 index 00000000000..f514f29c67d --- /dev/null +++ b/Documentation/powerpc/dts-bindings/ecm.txt @@ -0,0 +1,64 @@ +===================================================================== +E500 LAW & Coherency Module Device Tree Binding +Copyright (C) 2009 Freescale Semiconductor Inc. +===================================================================== + +Local Access Window (LAW) Node + +The LAW node represents the region of CCSR space where local access +windows are configured. For ECM based devices this is the first 4k +of CCSR space that includes CCSRBAR, ALTCBAR, ALTCAR, BPTR, and some +number of local access windows as specified by fsl,num-laws. + +PROPERTIES + + - compatible + Usage: required + Value type: <string> + Definition: Must include "fsl,ecm-law" + + - reg + Usage: required + Value type: <prop-encoded-array> + Definition: A standard property. The value specifies the + physical address offset and length of the CCSR space + registers. + + - fsl,num-laws + Usage: required + Value type: <u32> + Definition: The value specifies the number of local access + windows for this device. + +===================================================================== + +E500 Coherency Module Node + +The E500 LAW node represents the region of CCSR space where ECM config +and error reporting registers exist, this is the second 4k (0x1000) +of CCSR space. + +PROPERTIES + + - compatible + Usage: required + Value type: <string> + Definition: Must include "fsl,CHIP-ecm", "fsl,ecm" where + CHIP is the processor (mpc8572, mpc8544, etc.) + + - reg + Usage: required + Value type: <prop-encoded-array> + Definition: A standard property. The value specifies the + physical address offset and length of the CCSR space + registers. + + - interrupts + Usage: required + Value type: <prop-encoded-array> + + - interrupt-parent + Usage: required + Value type: <phandle> + +===================================================================== diff --git a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt index 78790d58dc2..6e37be1eeb2 100644 --- a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt +++ b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt @@ -17,6 +17,9 @@ Required properties: - model : precise model of the QE, Can be "QE", "CPM", or "CPM2" - reg : offset and length of the device registers. - bus-frequency : the clock frequency for QUICC Engine. +- fsl,qe-num-riscs: define how many RISC engines the QE has. +- fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the + threads. Recommended properties - brg-frequency : the internal clock source frequency for baud-rate diff --git a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt index 60084655776..5093ddf900d 100644 --- a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt +++ b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt @@ -5,8 +5,7 @@ for MMC, SD, and SDIO types of memory cards. Required properties: - compatible : should be - "fsl,<chip>-esdhc", "fsl,mpc8379-esdhc" for MPC83xx processors. - "fsl,<chip>-esdhc", "fsl,mpc8536-esdhc" for MPC85xx processors. + "fsl,<chip>-esdhc", "fsl,esdhc" - reg : should contain eSDHC registers location and length. - interrupts : should contain eSDHC interrupt. - interrupt-parent : interrupt source phandle. @@ -15,7 +14,7 @@ Required properties: Example: sdhci@2e000 { - compatible = "fsl,mpc8378-esdhc", "fsl,mpc8379-esdhc"; + compatible = "fsl,mpc8378-esdhc", "fsl,esdhc"; reg = <0x2e000 0x1000>; interrupts = <42 0x8>; interrupt-parent = <&ipic>; diff --git a/Documentation/powerpc/dts-bindings/fsl/mcm.txt b/Documentation/powerpc/dts-bindings/fsl/mcm.txt new file mode 100644 index 00000000000..4ceda9b3b41 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/fsl/mcm.txt @@ -0,0 +1,64 @@ +===================================================================== +MPX LAW & Coherency Module Device Tree Binding +Copyright (C) 2009 Freescale Semiconductor Inc. +===================================================================== + +Local Access Window (LAW) Node + +The LAW node represents the region of CCSR space where local access +windows are configured. For MCM based devices this is the first 4k +of CCSR space that includes CCSRBAR, ALTCBAR, ALTCAR, BPTR, and some +number of local access windows as specified by fsl,num-laws. + +PROPERTIES + + - compatible + Usage: required + Value type: <string> + Definition: Must include "fsl,mcm-law" + + - reg + Usage: required + Value type: <prop-encoded-array> + Definition: A standard property. The value specifies the + physical address offset and length of the CCSR space + registers. + + - fsl,num-laws + Usage: required + Value type: <u32> + Definition: The value specifies the number of local access + windows for this device. + +===================================================================== + +MPX Coherency Module Node + +The MPX LAW node represents the region of CCSR space where MCM config +and error reporting registers exist, this is the second 4k (0x1000) +of CCSR space. + +PROPERTIES + + - compatible + Usage: required + Value type: <string> + Definition: Must include "fsl,CHIP-mcm", "fsl,mcm" where + CHIP is the processor (mpc8641, mpc8610, etc.) + + - reg + Usage: required + Value type: <prop-encoded-array> + Definition: A standard property. The value specifies the + physical address offset and length of the CCSR space + registers. + + - interrupts + Usage: required + Value type: <prop-encoded-array> + + - interrupt-parent + Usage: required + Value type: <phandle> + +===================================================================== diff --git a/Documentation/rfkill.txt b/Documentation/rfkill.txt index 4d3ee317a4a..1b74b5f30af 100644 --- a/Documentation/rfkill.txt +++ b/Documentation/rfkill.txt @@ -1,575 +1,136 @@ -rfkill - RF switch subsystem support -==================================== +rfkill - RF kill switch support +=============================== -1 Introduction -2 Implementation details -3 Kernel driver guidelines -3.1 wireless device drivers -3.2 platform/switch drivers -3.3 input device drivers -4 Kernel API -5 Userspace support +1. Introduction +2. Implementation details +3. Kernel driver guidelines +4. Kernel API +5. Userspace support -1. Introduction: +1. Introduction -The rfkill switch subsystem exists to add a generic interface to circuitry that -can enable or disable the signal output of a wireless *transmitter* of any -type. By far, the most common use is to disable radio-frequency transmitters. +The rfkill subsystem provides a generic interface to disabling any radio +transmitter in the system. When a transmitter is blocked, it shall not +radiate any power. -Note that disabling the signal output means that the the transmitter is to be -made to not emit any energy when "blocked". rfkill is not about blocking data -transmissions, it is about blocking energy emission. +The subsystem also provides the ability to react on button presses and +disable all transmitters of a certain type (or all). This is intended for +situations where transmitters need to be turned off, for example on +aircraft. -The rfkill subsystem offers support for keys and switches often found on -laptops to enable wireless devices like WiFi and Bluetooth, so that these keys -and switches actually perform an action in all wireless devices of a given type -attached to the system. -The buttons to enable and disable the wireless transmitters are important in -situations where the user is for example using his laptop on a location where -radio-frequency transmitters _must_ be disabled (e.g. airplanes). -Because of this requirement, userspace support for the keys should not be made -mandatory. Because userspace might want to perform some additional smarter -tasks when the key is pressed, rfkill provides userspace the possibility to -take over the task to handle the key events. - -=============================================================================== -2: Implementation details +2. Implementation details The rfkill subsystem is composed of various components: the rfkill class, the rfkill-input module (an input layer handler), and some specific input layer events. -The rfkill class provides kernel drivers with an interface that allows them to -know when they should enable or disable a wireless network device transmitter. -This is enabled by the CONFIG_RFKILL Kconfig option. - -The rfkill class support makes sure userspace will be notified of all state -changes on rfkill devices through uevents. It provides a notification chain -for interested parties in the kernel to also get notified of rfkill state -changes in other drivers. It creates several sysfs entries which can be used -by userspace. See section "Userspace support". - -The rfkill-input module provides the kernel with the ability to implement a -basic response when the user presses a key or button (or toggles a switch) -related to rfkill functionality. It is an in-kernel implementation of default -policy of reacting to rfkill-related input events and neither mandatory nor -required for wireless drivers to operate. It is enabled by the -CONFIG_RFKILL_INPUT Kconfig option. - -rfkill-input is a rfkill-related events input layer handler. This handler will -listen to all rfkill key events and will change the rfkill state of the -wireless devices accordingly. With this option enabled userspace could either -do nothing or simply perform monitoring tasks. - -The rfkill-input module also provides EPO (emergency power-off) functionality -for all wireless transmitters. This function cannot be overridden, and it is -always active. rfkill EPO is related to *_RFKILL_ALL input layer events. - - -Important terms for the rfkill subsystem: - -In order to avoid confusion, we avoid the term "switch" in rfkill when it is -referring to an electronic control circuit that enables or disables a -transmitter. We reserve it for the physical device a human manipulates -(which is an input device, by the way): - -rfkill switch: - - A physical device a human manipulates. Its state can be perceived by - the kernel either directly (through a GPIO pin, ACPI GPE) or by its - effect on a rfkill line of a wireless device. - -rfkill controller: - - A hardware circuit that controls the state of a rfkill line, which a - kernel driver can interact with *to modify* that state (i.e. it has - either write-only or read/write access). - -rfkill line: - - An input channel (hardware or software) of a wireless device, which - causes a wireless transmitter to stop emitting energy (BLOCK) when it - is active. Point of view is extremely important here: rfkill lines are - always seen from the PoV of a wireless device (and its driver). - -soft rfkill line/software rfkill line: - - A rfkill line the wireless device driver can directly change the state - of. Related to rfkill_state RFKILL_STATE_SOFT_BLOCKED. - -hard rfkill line/hardware rfkill line: - - A rfkill line that works fully in hardware or firmware, and that cannot - be overridden by the kernel driver. The hardware device or the - firmware just exports its status to the driver, but it is read-only. - Related to rfkill_state RFKILL_STATE_HARD_BLOCKED. - -The enum rfkill_state describes the rfkill state of a transmitter: - -When a rfkill line or rfkill controller is in the RFKILL_STATE_UNBLOCKED state, -the wireless transmitter (radio TX circuit for example) is *enabled*. When the -it is in the RFKILL_STATE_SOFT_BLOCKED or RFKILL_STATE_HARD_BLOCKED, the -wireless transmitter is to be *blocked* from operating. - -RFKILL_STATE_SOFT_BLOCKED indicates that a call to toggle_radio() can change -that state. RFKILL_STATE_HARD_BLOCKED indicates that a call to toggle_radio() -will not be able to change the state and will return with a suitable error if -attempts are made to set the state to RFKILL_STATE_UNBLOCKED. - -RFKILL_STATE_HARD_BLOCKED is used by drivers to signal that the device is -locked in the BLOCKED state by a hardwire rfkill line (typically an input pin -that, when active, forces the transmitter to be disabled) which the driver -CANNOT override. - -Full rfkill functionality requires two different subsystems to cooperate: the -input layer and the rfkill class. The input layer issues *commands* to the -entire system requesting that devices registered to the rfkill class change -state. The way this interaction happens is not complex, but it is not obvious -either: - -Kernel Input layer: - - * Generates KEY_WWAN, KEY_WLAN, KEY_BLUETOOTH, SW_RFKILL_ALL, and - other such events when the user presses certain keys, buttons, or - toggles certain physical switches. - - THE INPUT LAYER IS NEVER USED TO PROPAGATE STATUS, NOTIFICATIONS OR THE - KIND OF STUFF AN ON-SCREEN-DISPLAY APPLICATION WOULD REPORT. It is - used to issue *commands* for the system to change behaviour, and these - commands may or may not be carried out by some kernel driver or - userspace application. It follows that doing user feedback based only - on input events is broken, as there is no guarantee that an input event - will be acted upon. - - Most wireless communication device drivers implementing rfkill - functionality MUST NOT generate these events, and have no reason to - register themselves with the input layer. Doing otherwise is a common - misconception. There is an API to propagate rfkill status change - information, and it is NOT the input layer. - -rfkill class: - - * Calls a hook in a driver to effectively change the wireless - transmitter state; - * Keeps track of the wireless transmitter state (with help from - the driver); - * Generates userspace notifications (uevents) and a call to a - notification chain (kernel) when there is a wireless transmitter - state change; - * Connects a wireless communications driver with the common rfkill - control system, which, for example, allows actions such as - "switch all bluetooth devices offline" to be carried out by - userspace or by rfkill-input. - - THE RFKILL CLASS NEVER ISSUES INPUT EVENTS. THE RFKILL CLASS DOES - NOT LISTEN TO INPUT EVENTS. NO DRIVER USING THE RFKILL CLASS SHALL - EVER LISTEN TO, OR ACT ON RFKILL INPUT EVENTS. Doing otherwise is - a layering violation. - - Most wireless data communication drivers in the kernel have just to - implement the rfkill class API to work properly. Interfacing to the - input layer is not often required (and is very often a *bug*) on - wireless drivers. - - Platform drivers often have to attach to the input layer to *issue* - (but never to listen to) rfkill events for rfkill switches, and also to - the rfkill class to export a control interface for the platform rfkill - controllers to the rfkill subsystem. This does NOT mean the rfkill - switch is attached to a rfkill class (doing so is almost always wrong). - It just means the same kernel module is the driver for different - devices (rfkill switches and rfkill controllers). - - -Userspace input handlers (uevents) or kernel input handlers (rfkill-input): - - * Implements the policy of what should happen when one of the input - layer events related to rfkill operation is received. - * Uses the sysfs interface (userspace) or private rfkill API calls - to tell the devices registered with the rfkill class to change - their state (i.e. translates the input layer event into real - action). - - * rfkill-input implements EPO by handling EV_SW SW_RFKILL_ALL 0 - (power off all transmitters) in a special way: it ignores any - overrides and local state cache and forces all transmitters to the - RFKILL_STATE_SOFT_BLOCKED state (including those which are already - supposed to be BLOCKED). - * rfkill EPO will remain active until rfkill-input receives an - EV_SW SW_RFKILL_ALL 1 event. While the EPO is active, transmitters - are locked in the blocked state (rfkill will refuse to unblock them). - * rfkill-input implements different policies that the user can - select for handling EV_SW SW_RFKILL_ALL 1. It will unlock rfkill, - and either do nothing (leave transmitters blocked, but now unlocked), - restore the transmitters to their state before the EPO, or unblock - them all. - -Userspace uevent handler or kernel platform-specific drivers hooked to the -rfkill notifier chain: - - * Taps into the rfkill notifier chain or to KOBJ_CHANGE uevents, - in order to know when a device that is registered with the rfkill - class changes state; - * Issues feedback notifications to the user; - * In the rare platforms where this is required, synthesizes an input - event to command all *OTHER* rfkill devices to also change their - statues when a specific rfkill device changes state. - - -=============================================================================== -3: Kernel driver guidelines - -Remember: point-of-view is everything for a driver that connects to the rfkill -subsystem. All the details below must be measured/perceived from the point of -view of the specific driver being modified. - -The first thing one needs to know is whether his driver should be talking to -the rfkill class or to the input layer. In rare cases (platform drivers), it -could happen that you need to do both, as platform drivers often handle a -variety of devices in the same driver. - -Do not mistake input devices for rfkill controllers. The only type of "rfkill -switch" device that is to be registered with the rfkill class are those -directly controlling the circuits that cause a wireless transmitter to stop -working (or the software equivalent of them), i.e. what we call a rfkill -controller. Every other kind of "rfkill switch" is just an input device and -MUST NOT be registered with the rfkill class. - -A driver should register a device with the rfkill class when ALL of the -following conditions are met (they define a rfkill controller): - -1. The device is/controls a data communications wireless transmitter; - -2. The kernel can interact with the hardware/firmware to CHANGE the wireless - transmitter state (block/unblock TX operation); - -3. The transmitter can be made to not emit any energy when "blocked": - rfkill is not about blocking data transmissions, it is about blocking - energy emission; - -A driver should register a device with the input subsystem to issue -rfkill-related events (KEY_WLAN, KEY_BLUETOOTH, KEY_WWAN, KEY_WIMAX, -SW_RFKILL_ALL, etc) when ALL of the folowing conditions are met: - -1. It is directly related to some physical device the user interacts with, to - command the O.S./firmware/hardware to enable/disable a data communications - wireless transmitter. - - Examples of the physical device are: buttons, keys and switches the user - will press/touch/slide/switch to enable or disable the wireless - communication device. - -2. It is NOT slaved to another device, i.e. there is no other device that - issues rfkill-related input events in preference to this one. - - Please refer to the corner cases and examples section for more details. - -When in doubt, do not issue input events. For drivers that should generate -input events in some platforms, but not in others (e.g. b43), the best solution -is to NEVER generate input events in the first place. That work should be -deferred to a platform-specific kernel module (which will know when to generate -events through the rfkill notifier chain) or to userspace. This avoids the -usual maintenance problems with DMI whitelisting. - - -Corner cases and examples: -==================================== - -1. If the device is an input device that, because of hardware or firmware, -causes wireless transmitters to be blocked regardless of the kernel's will, it -is still just an input device, and NOT to be registered with the rfkill class. - -2. If the wireless transmitter switch control is read-only, it is an input -device and not to be registered with the rfkill class (and maybe not to be made -an input layer event source either, see below). - -3. If there is some other device driver *closer* to the actual hardware the -user interacted with (the button/switch/key) to issue an input event, THAT is -the device driver that should be issuing input events. - -E.g: - [RFKILL slider switch] -- [GPIO hardware] -- [WLAN card rf-kill input] - (platform driver) (wireless card driver) - -The user is closer to the RFKILL slide switch plaform driver, so the driver -which must issue input events is the platform driver looking at the GPIO -hardware, and NEVER the wireless card driver (which is just a slave). It is -very likely that there are other leaves than just the WLAN card rf-kill input -(e.g. a bluetooth card, etc)... - -On the other hand, some embedded devices do this: - - [RFKILL slider switch] -- [WLAN card rf-kill input] - (wireless card driver) - -In this situation, the wireless card driver *could* register itself as an input -device and issue rf-kill related input events... but in order to AVOID the need -for DMI whitelisting, the wireless card driver does NOT do it. Userspace (HAL) -or a platform driver (that exists only on these embedded devices) will do the -dirty job of issuing the input events. - - -COMMON MISTAKES in kernel drivers, related to rfkill: -==================================== - -1. NEVER confuse input device keys and buttons with input device switches. - - 1a. Switches are always set or reset. They report the current state - (on position or off position). - - 1b. Keys and buttons are either in the pressed or not-pressed state, and - that's it. A "button" that latches down when you press it, and - unlatches when you press it again is in fact a switch as far as input - devices go. - -Add the SW_* events you need for switches, do NOT try to emulate a button using -KEY_* events just because there is no such SW_* event yet. Do NOT try to use, -for example, KEY_BLUETOOTH when you should be using SW_BLUETOOTH instead. - -2. Input device switches (sources of EV_SW events) DO store their current state -(so you *must* initialize it by issuing a gratuitous input layer event on -driver start-up and also when resuming from sleep), and that state CAN be -queried from userspace through IOCTLs. There is no sysfs interface for this, -but that doesn't mean you should break things trying to hook it to the rfkill -class to get a sysfs interface :-) - -3. Do not issue *_RFKILL_ALL events by default, unless you are sure it is the -correct event for your switch/button. These events are emergency power-off -events when they are trying to turn the transmitters off. An example of an -input device which SHOULD generate *_RFKILL_ALL events is the wireless-kill -switch in a laptop which is NOT a hotkey, but a real sliding/rocker switch. -An example of an input device which SHOULD NOT generate *_RFKILL_ALL events by -default, is any sort of hot key that is type-specific (e.g. the one for WLAN). - - -3.1 Guidelines for wireless device drivers ------------------------------------------- - -(in this text, rfkill->foo means the foo field of struct rfkill). - -1. Each independent transmitter in a wireless device (usually there is only one -transmitter per device) should have a SINGLE rfkill class attached to it. - -2. If the device does not have any sort of hardware assistance to allow the -driver to rfkill the device, the driver should emulate it by taking all actions -required to silence the transmitter. - -3. If it is impossible to silence the transmitter (i.e. it still emits energy, -even if it is just in brief pulses, when there is no data to transmit and there -is no hardware support to turn it off) do NOT lie to the users. Do not attach -it to a rfkill class. The rfkill subsystem does not deal with data -transmission, it deals with energy emission. If the transmitter is emitting -energy, it is not blocked in rfkill terms. - -4. It doesn't matter if the device has multiple rfkill input lines affecting -the same transmitter, their combined state is to be exported as a single state -per transmitter (see rule 1). - -This rule exists because users of the rfkill subsystem expect to get (and set, -when possible) the overall transmitter rfkill state, not of a particular rfkill -line. - -5. The wireless device driver MUST NOT leave the transmitter enabled during -suspend and hibernation unless: +The rfkill class is provided for kernel drivers to register their radio +transmitter with the kernel, provide methods for turning it on and off and, +optionally, letting the system know about hardware-disabled states that may +be implemented on the device. This code is enabled with the CONFIG_RFKILL +Kconfig option, which drivers can "select". - 5.1. The transmitter has to be enabled for some sort of functionality - like wake-on-wireless-packet or autonomous packed forwarding in a mesh - network, and that functionality is enabled for this suspend/hibernation - cycle. +The rfkill class code also notifies userspace of state changes, this is +achieved via uevents. It also provides some sysfs files for userspace to +check the status of radio transmitters. See the "Userspace support" section +below. -AND - 5.2. The device was not on a user-requested BLOCKED state before - the suspend (i.e. the driver must NOT unblock a device, not even - to support wake-on-wireless-packet or remain in the mesh). +The rfkill-input code implements a basic response to rfkill buttons -- it +implements turning on/off all devices of a certain class (or all). -In other words, there is absolutely no allowed scenario where a driver can -automatically take action to unblock a rfkill controller (obviously, this deals -with scenarios where soft-blocking or both soft and hard blocking is happening. -Scenarios where hardware rfkill lines are the only ones blocking the -transmitter are outside of this rule, since the wireless device driver does not -control its input hardware rfkill lines in the first place). +When the device is hard-blocked (either by a call to rfkill_set_hw_state() +or from query_hw_block) set_block() will be invoked but drivers can well +ignore the method call since they can use the return value of the function +rfkill_set_hw_state() to sync the software state instead of keeping track +of calls to set_block(). -6. During resume, rfkill will try to restore its previous state. -7. After a rfkill class is suspended, it will *not* call rfkill->toggle_radio -until it is resumed. +The entire functionality is spread over more than one subsystem: + * The kernel input layer generates KEY_WWAN, KEY_WLAN etc. and + SW_RFKILL_ALL -- when the user presses a button. Drivers for radio + transmitters generally do not register to the input layer, unless the + device really provides an input device (i.e. a button that has no + effect other than generating a button press event) -Example of a WLAN wireless driver connected to the rfkill subsystem: --------------------------------------------------------------------- + * The rfkill-input code hooks up to these events and switches the soft-block + of the various radio transmitters, depending on the button type. -A certain WLAN card has one input pin that causes it to block the transmitter -and makes the status of that input pin available (only for reading!) to the -kernel driver. This is a hard rfkill input line (it cannot be overridden by -the kernel driver). + * The rfkill drivers turn off/on their transmitters as requested. -The card also has one PCI register that, if manipulated by the driver, causes -it to block the transmitter. This is a soft rfkill input line. + * The rfkill class will generate userspace notifications (uevents) to tell + userspace what the current state is. -It has also a thermal protection circuitry that shuts down its transmitter if -the card overheats, and makes the status of that protection available (only for -reading!) to the kernel driver. This is also a hard rfkill input line. -If either one of these rfkill lines are active, the transmitter is blocked by -the hardware and forced offline. -The driver should allocate and attach to its struct device *ONE* instance of -the rfkill class (there is only one transmitter). +3. Kernel driver guidelines -It can implement the get_state() hook, and return RFKILL_STATE_HARD_BLOCKED if -either one of its two hard rfkill input lines are active. If the two hard -rfkill lines are inactive, it must return RFKILL_STATE_SOFT_BLOCKED if its soft -rfkill input line is active. Only if none of the rfkill input lines are -active, will it return RFKILL_STATE_UNBLOCKED. -Since the device has a hardware rfkill line, it IS subject to state changes -external to rfkill. Therefore, the driver must make sure that it calls -rfkill_force_state() to keep the status always up-to-date, and it must do a -rfkill_force_state() on resume from sleep. +Drivers for radio transmitters normally implement only the rfkill class. +These drivers may not unblock the transmitter based on own decisions, they +should act on information provided by the rfkill class only. -Every time the driver gets a notification from the card that one of its rfkill -lines changed state (polling might be needed on badly designed cards that don't -generate interrupts for such events), it recomputes the rfkill state as per -above, and calls rfkill_force_state() to update it. +Platform drivers might implement input devices if the rfkill button is just +that, a button. If that button influences the hardware then you need to +implement an rfkill class instead. This also applies if the platform provides +a way to turn on/off the transmitter(s). -The driver should implement the toggle_radio() hook, that: +During suspend/hibernation, transmitters should only be left enabled when +wake-on wlan or similar functionality requires it and the device wasn't +blocked before suspend/hibernate. Note that it may be necessary to update +the rfkill subsystem's idea of what the current state is at resume time if +the state may have changed over suspend. -1. Returns an error if one of the hardware rfkill lines are active, and the -caller asked for RFKILL_STATE_UNBLOCKED. -2. Activates the soft rfkill line if the caller asked for state -RFKILL_STATE_SOFT_BLOCKED. It should do this even if one of the hard rfkill -lines are active, effectively double-blocking the transmitter. -3. Deactivates the soft rfkill line if none of the hardware rfkill lines are -active and the caller asked for RFKILL_STATE_UNBLOCKED. - -=============================================================================== -4: Kernel API +4. Kernel API To build a driver with rfkill subsystem support, the driver should depend on -(or select) the Kconfig symbol RFKILL; it should _not_ depend on RKFILL_INPUT. +(or select) the Kconfig symbol RFKILL. The hardware the driver talks to may be write-only (where the current state of the hardware is unknown), or read-write (where the hardware can be queried about its current state). -The rfkill class will call the get_state hook of a device every time it needs -to know the *real* current state of the hardware. This can happen often, but -it does not do any polling, so it is not enough on hardware that is subject -to state changes outside of the rfkill subsystem. - -Therefore, calling rfkill_force_state() when a state change happens is -mandatory when the device has a hardware rfkill line, or when something else -like the firmware could cause its state to be changed without going through the -rfkill class. - -Some hardware provides events when its status changes. In these cases, it is -best for the driver to not provide a get_state hook, and instead register the -rfkill class *already* with the correct status, and keep it updated using -rfkill_force_state() when it gets an event from the hardware. - -rfkill_force_state() must be used on the device resume handlers to update the -rfkill status, should there be any chance of the device status changing during -the sleep. - -There is no provision for a statically-allocated rfkill struct. You must -use rfkill_allocate() to allocate one. - -You should: - - rfkill_allocate() - - modify rfkill fields (flags, name) - - modify state to the current hardware state (THIS IS THE ONLY TIME - YOU CAN ACCESS state DIRECTLY) - - rfkill_register() - -The only way to set a device to the RFKILL_STATE_HARD_BLOCKED state is through -a suitable return of get_state() or through rfkill_force_state(). +Calling rfkill_set_hw_state() when a state change happens is required from +rfkill drivers that control devices that can be hard-blocked unless they also +assign the poll_hw_block() callback (then the rfkill core will poll the +device). Don't do this unless you cannot get the event in any other way. -When a device is in the RFKILL_STATE_HARD_BLOCKED state, the only way to switch -it to a different state is through a suitable return of get_state() or through -rfkill_force_state(). -If toggle_radio() is called to set a device to state RFKILL_STATE_SOFT_BLOCKED -when that device is already at the RFKILL_STATE_HARD_BLOCKED state, it should -not return an error. Instead, it should try to double-block the transmitter, -so that its state will change from RFKILL_STATE_HARD_BLOCKED to -RFKILL_STATE_SOFT_BLOCKED should the hardware blocking cease. - -Please refer to the source for more documentation. - -=============================================================================== -5: Userspace support - -rfkill devices issue uevents (with an action of "change"), with the following -environment variables set: - -RFKILL_NAME -RFKILL_STATE -RFKILL_TYPE -The ABI for these variables is defined by the sysfs attributes. It is best -to take a quick look at the source to make sure of the possible values. +5. Userspace support -It is expected that HAL will trap those, and bridge them to DBUS, etc. These -events CAN and SHOULD be used to give feedback to the user about the rfkill -status of the system. - -Input devices may issue events that are related to rfkill. These are the -various KEY_* events and SW_* events supported by rfkill-input.c. - -******IMPORTANT****** -When rfkill-input is ACTIVE, userspace is NOT TO CHANGE THE STATE OF AN RFKILL -SWITCH IN RESPONSE TO AN INPUT EVENT also handled by rfkill-input, unless it -has set to true the user_claim attribute for that particular switch. This rule -is *absolute*; do NOT violate it. -******IMPORTANT****** - -Userspace must not assume it is the only source of control for rfkill switches. -Their state CAN and WILL change due to firmware actions, direct user actions, -and the rfkill-input EPO override for *_RFKILL_ALL. - -When rfkill-input is not active, userspace must initiate a rfkill status -change by writing to the "state" attribute in order for anything to happen. - -Take particular care to implement EV_SW SW_RFKILL_ALL properly. When that -switch is set to OFF, *every* rfkill device *MUST* be immediately put into the -RFKILL_STATE_SOFT_BLOCKED state, no questions asked. - -The following sysfs entries will be created: +The following sysfs entries exist for every rfkill device: name: Name assigned by driver to this key (interface or driver name). type: Name of the key type ("wlan", "bluetooth", etc). state: Current state of the transmitter 0: RFKILL_STATE_SOFT_BLOCKED - transmitter is forced off, but one can override it - by a write to the state attribute; + transmitter is turned off by software 1: RFKILL_STATE_UNBLOCKED - transmiter is NOT forced off, and may operate if - all other conditions for such operation are met - (such as interface is up and configured, etc); + transmitter is (potentially) active 2: RFKILL_STATE_HARD_BLOCKED transmitter is forced off by something outside of - the driver's control. One cannot set a device to - this state through writes to the state attribute; - claim: 1: Userspace handles events, 0: Kernel handles events - -Both the "state" and "claim" entries are also writable. For the "state" entry -this means that when 1 or 0 is written, the device rfkill state (if not yet in -the requested state), will be will be toggled accordingly. - -For the "claim" entry writing 1 to it means that the kernel no longer handles -key events even though RFKILL_INPUT input was enabled. When "claim" has been -set to 0, userspace should make sure that it listens for the input events or -check the sysfs "state" entry regularly to correctly perform the required tasks -when the rkfill key is pressed. - -A note about input devices and EV_SW events: - -In order to know the current state of an input device switch (like -SW_RFKILL_ALL), you will need to use an IOCTL. That information is not -available through sysfs in a generic way at this time, and it is not available -through the rfkill class AT ALL. + the driver's control. + claim: 0: Kernel handles events (currently always reads that value) + +rfkill devices also issue uevents (with an action of "change"), with the +following environment variables set: + +RFKILL_NAME +RFKILL_STATE +RFKILL_TYPE + +The contents of these variables corresponds to the "name", "state" and +"type" sysfs files explained above. + +An alternative userspace interface exists as a misc device /dev/rfkill, +which allows userspace to obtain and set the state of rfkill devices and +sets of devices. It also notifies userspace about device addition and +removal. The API is a simple read/write API that is defined in +linux/rfkill.h. |