diff options
author | Paul Mackerras <paulus@samba.org> | 2007-10-03 15:33:17 +1000 |
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committer | Paul Mackerras <paulus@samba.org> | 2007-10-03 15:33:17 +1000 |
commit | 70f227d8846a8a9b1f36f71c42e11cc7c6e9408d (patch) | |
tree | fb4dd5c8240bdaada819fb569c01a392b52847b9 /Documentation | |
parent | a0c7ce9c877ceef8428798ac91fb794f83609aed (diff) | |
parent | f778089cb2445dfc6dfd30a7a567925fd8589f1e (diff) | |
download | kernel_samsung_crespo-70f227d8846a8a9b1f36f71c42e11cc7c6e9408d.zip kernel_samsung_crespo-70f227d8846a8a9b1f36f71c42e11cc7c6e9408d.tar.gz kernel_samsung_crespo-70f227d8846a8a9b1f36f71c42e11cc7c6e9408d.tar.bz2 |
Merge branch 'linux-2.6' into for-2.6.24
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/crypto/async-tx-api.txt | 219 | ||||
-rw-r--r-- | Documentation/devices.txt | 2 | ||||
-rw-r--r-- | Documentation/input/iforce-protocol.txt | 508 | ||||
-rw-r--r-- | Documentation/lguest/lguest.c | 2 |
4 files changed, 476 insertions, 255 deletions
diff --git a/Documentation/crypto/async-tx-api.txt b/Documentation/crypto/async-tx-api.txt new file mode 100644 index 0000000..c1e9545 --- /dev/null +++ b/Documentation/crypto/async-tx-api.txt @@ -0,0 +1,219 @@ + Asynchronous Transfers/Transforms API + +1 INTRODUCTION + +2 GENEALOGY + +3 USAGE +3.1 General format of the API +3.2 Supported operations +3.3 Descriptor management +3.4 When does the operation execute? +3.5 When does the operation complete? +3.6 Constraints +3.7 Example + +4 DRIVER DEVELOPER NOTES +4.1 Conformance points +4.2 "My application needs finer control of hardware channels" + +5 SOURCE + +--- + +1 INTRODUCTION + +The async_tx API provides methods for describing a chain of asynchronous +bulk memory transfers/transforms with support for inter-transactional +dependencies. It is implemented as a dmaengine client that smooths over +the details of different hardware offload engine implementations. Code +that is written to the API can optimize for asynchronous operation and +the API will fit the chain of operations to the available offload +resources. + +2 GENEALOGY + +The API was initially designed to offload the memory copy and +xor-parity-calculations of the md-raid5 driver using the offload engines +present in the Intel(R) Xscale series of I/O processors. It also built +on the 'dmaengine' layer developed for offloading memory copies in the +network stack using Intel(R) I/OAT engines. The following design +features surfaced as a result: +1/ implicit synchronous path: users of the API do not need to know if + the platform they are running on has offload capabilities. The + operation will be offloaded when an engine is available and carried out + in software otherwise. +2/ cross channel dependency chains: the API allows a chain of dependent + operations to be submitted, like xor->copy->xor in the raid5 case. The + API automatically handles cases where the transition from one operation + to another implies a hardware channel switch. +3/ dmaengine extensions to support multiple clients and operation types + beyond 'memcpy' + +3 USAGE + +3.1 General format of the API: +struct dma_async_tx_descriptor * +async_<operation>(<op specific parameters>, + enum async_tx_flags flags, + struct dma_async_tx_descriptor *dependency, + dma_async_tx_callback callback_routine, + void *callback_parameter); + +3.2 Supported operations: +memcpy - memory copy between a source and a destination buffer +memset - fill a destination buffer with a byte value +xor - xor a series of source buffers and write the result to a + destination buffer +xor_zero_sum - xor a series of source buffers and set a flag if the + result is zero. The implementation attempts to prevent + writes to memory + +3.3 Descriptor management: +The return value is non-NULL and points to a 'descriptor' when the operation +has been queued to execute asynchronously. Descriptors are recycled +resources, under control of the offload engine driver, to be reused as +operations complete. When an application needs to submit a chain of +operations it must guarantee that the descriptor is not automatically recycled +before the dependency is submitted. This requires that all descriptors be +acknowledged by the application before the offload engine driver is allowed to +recycle (or free) the descriptor. A descriptor can be acked by one of the +following methods: +1/ setting the ASYNC_TX_ACK flag if no child operations are to be submitted +2/ setting the ASYNC_TX_DEP_ACK flag to acknowledge the parent + descriptor of a new operation. +3/ calling async_tx_ack() on the descriptor. + +3.4 When does the operation execute? +Operations do not immediately issue after return from the +async_<operation> call. Offload engine drivers batch operations to +improve performance by reducing the number of mmio cycles needed to +manage the channel. Once a driver-specific threshold is met the driver +automatically issues pending operations. An application can force this +event by calling async_tx_issue_pending_all(). This operates on all +channels since the application has no knowledge of channel to operation +mapping. + +3.5 When does the operation complete? +There are two methods for an application to learn about the completion +of an operation. +1/ Call dma_wait_for_async_tx(). This call causes the CPU to spin while + it polls for the completion of the operation. It handles dependency + chains and issuing pending operations. +2/ Specify a completion callback. The callback routine runs in tasklet + context if the offload engine driver supports interrupts, or it is + called in application context if the operation is carried out + synchronously in software. The callback can be set in the call to + async_<operation>, or when the application needs to submit a chain of + unknown length it can use the async_trigger_callback() routine to set a + completion interrupt/callback at the end of the chain. + +3.6 Constraints: +1/ Calls to async_<operation> are not permitted in IRQ context. Other + contexts are permitted provided constraint #2 is not violated. +2/ Completion callback routines cannot submit new operations. This + results in recursion in the synchronous case and spin_locks being + acquired twice in the asynchronous case. + +3.7 Example: +Perform a xor->copy->xor operation where each operation depends on the +result from the previous operation: + +void complete_xor_copy_xor(void *param) +{ + printk("complete\n"); +} + +int run_xor_copy_xor(struct page **xor_srcs, + int xor_src_cnt, + struct page *xor_dest, + size_t xor_len, + struct page *copy_src, + struct page *copy_dest, + size_t copy_len) +{ + struct dma_async_tx_descriptor *tx; + + tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, + ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL); + tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len, + ASYNC_TX_DEP_ACK, tx, NULL, NULL); + tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, + ASYNC_TX_XOR_DROP_DST | ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, + tx, complete_xor_copy_xor, NULL); + + async_tx_issue_pending_all(); +} + +See include/linux/async_tx.h for more information on the flags. See the +ops_run_* and ops_complete_* routines in drivers/md/raid5.c for more +implementation examples. + +4 DRIVER DEVELOPMENT NOTES +4.1 Conformance points: +There are a few conformance points required in dmaengine drivers to +accommodate assumptions made by applications using the async_tx API: +1/ Completion callbacks are expected to happen in tasklet context +2/ dma_async_tx_descriptor fields are never manipulated in IRQ context +3/ Use async_tx_run_dependencies() in the descriptor clean up path to + handle submission of dependent operations + +4.2 "My application needs finer control of hardware channels" +This requirement seems to arise from cases where a DMA engine driver is +trying to support device-to-memory DMA. The dmaengine and async_tx +implementations were designed for offloading memory-to-memory +operations; however, there are some capabilities of the dmaengine layer +that can be used for platform-specific channel management. +Platform-specific constraints can be handled by registering the +application as a 'dma_client' and implementing a 'dma_event_callback' to +apply a filter to the available channels in the system. Before showing +how to implement a custom dma_event callback some background of +dmaengine's client support is required. + +The following routines in dmaengine support multiple clients requesting +use of a channel: +- dma_async_client_register(struct dma_client *client) +- dma_async_client_chan_request(struct dma_client *client) + +dma_async_client_register takes a pointer to an initialized dma_client +structure. It expects that the 'event_callback' and 'cap_mask' fields +are already initialized. + +dma_async_client_chan_request triggers dmaengine to notify the client of +all channels that satisfy the capability mask. It is up to the client's +event_callback routine to track how many channels the client needs and +how many it is currently using. The dma_event_callback routine returns a +dma_state_client code to let dmaengine know the status of the +allocation. + +Below is the example of how to extend this functionality for +platform-specific filtering of the available channels beyond the +standard capability mask: + +static enum dma_state_client +my_dma_client_callback(struct dma_client *client, + struct dma_chan *chan, enum dma_state state) +{ + struct dma_device *dma_dev; + struct my_platform_specific_dma *plat_dma_dev; + + dma_dev = chan->device; + plat_dma_dev = container_of(dma_dev, + struct my_platform_specific_dma, + dma_dev); + + if (!plat_dma_dev->platform_specific_capability) + return DMA_DUP; + + . . . +} + +5 SOURCE +include/linux/dmaengine.h: core header file for DMA drivers and clients +drivers/dma/dmaengine.c: offload engine channel management routines +drivers/dma/: location for offload engine drivers +include/linux/async_tx.h: core header file for the async_tx api +crypto/async_tx/async_tx.c: async_tx interface to dmaengine and common code +crypto/async_tx/async_memcpy.c: copy offload +crypto/async_tx/async_memset.c: memory fill offload +crypto/async_tx/async_xor.c: xor and xor zero sum offload diff --git a/Documentation/devices.txt b/Documentation/devices.txt index 8de132a..6c46730 100644 --- a/Documentation/devices.txt +++ b/Documentation/devices.txt @@ -94,6 +94,8 @@ Your cooperation is appreciated. 9 = /dev/urandom Faster, less secure random number gen. 10 = /dev/aio Asynchronous I/O notification interface 11 = /dev/kmsg Writes to this come out as printk's + 12 = /dev/oldmem Used by crashdump kernels to access + the memory of the kernel that crashed. 1 block RAM disk 0 = /dev/ram0 First RAM disk diff --git a/Documentation/input/iforce-protocol.txt b/Documentation/input/iforce-protocol.txt index 95df4ca..8777d2d 100644 --- a/Documentation/input/iforce-protocol.txt +++ b/Documentation/input/iforce-protocol.txt @@ -1,254 +1,254 @@ -** Introduction
-This document describes what I managed to discover about the protocol used to
-specify force effects to I-Force 2.0 devices. None of this information comes
-from Immerse. That's why you should not trust what is written in this
-document. This document is intended to help understanding the protocol.
-This is not a reference. Comments and corrections are welcome. To contact me,
-send an email to: deneux@ifrance.com
-
-** WARNING **
-I may not be held responsible for any dammage or harm caused if you try to
-send data to your I-Force device based on what you read in this document.
-
-** Preliminary Notes:
-All values are hexadecimal with big-endian encoding (msb on the left). Beware,
-values inside packets are encoded using little-endian. Bytes whose roles are
-unknown are marked ??? Information that needs deeper inspection is marked (?)
-
-** General form of a packet **
-This is how packets look when the device uses the rs232 to communicate.
-2B OP LEN DATA CS
-CS is the checksum. It is equal to the exclusive or of all bytes.
-
-When using USB:
-OP DATA
-The 2B, LEN and CS fields have disappeared, probably because USB handles frames and
-data corruption is handled or unsignificant.
-
-First, I describe effects that are sent by the device to the computer
-
-** Device input state
-This packet is used to indicate the state of each button and the value of each
-axis
-OP= 01 for a joystick, 03 for a wheel
-LEN= Varies from device to device
-00 X-Axis lsb
-01 X-Axis msb
-02 Y-Axis lsb, or gas pedal for a wheel
-03 Y-Axis msb, or brake pedal for a wheel
-04 Throttle
-05 Buttons
-06 Lower 4 bits: Buttons
- Upper 4 bits: Hat
-07 Rudder
-
-** Device effects states
-OP= 02
-LEN= Varies
-00 ? Bit 1 (Value 2) is the value of the deadman switch
-01 Bit 8 is set if the effect is playing. Bits 0 to 7 are the effect id.
-02 ??
-03 Address of parameter block changed (lsb)
-04 Address of parameter block changed (msb)
-05 Address of second parameter block changed (lsb)
-... depending on the number of parameter blocks updated
-
-** Force effect **
-OP= 01
-LEN= 0e
-00 Channel (when playing several effects at the same time, each must be assigned a channel)
-01 Wave form
- Val 00 Constant
- Val 20 Square
- Val 21 Triangle
- Val 22 Sine
- Val 23 Sawtooth up
- Val 24 Sawtooth down
- Val 40 Spring (Force = f(pos))
- Val 41 Friction (Force = f(velocity)) and Inertia (Force = f(acceleration))
-
-
-02 Axes affected and trigger
- Bits 4-7: Val 2 = effect along one axis. Byte 05 indicates direction
- Val 4 = X axis only. Byte 05 must contain 5a
- Val 8 = Y axis only. Byte 05 must contain b4
- Val c = X and Y axes. Bytes 05 must contain 60
- Bits 0-3: Val 0 = No trigger
- Val x+1 = Button x triggers the effect
- When the whole byte is 0, cancel the previously set trigger
-
-03-04 Duration of effect (little endian encoding, in ms)
-
-05 Direction of effect, if applicable. Else, see 02 for value to assign.
-
-06-07 Minimum time between triggering.
-
-08-09 Address of periodicity or magnitude parameters
-0a-0b Address of attack and fade parameters, or ffff if none.
-*or*
-08-09 Address of interactive parameters for X-axis, or ffff if not applicable
-0a-0b Address of interactive parameters for Y-axis, or ffff if not applicable
-
-0c-0d Delay before execution of effect (little endian encoding, in ms)
-
-
-** Time based parameters **
-
-*** Attack and fade ***
-OP= 02
-LEN= 08
-00-01 Address where to store the parameteres
-02-03 Duration of attack (little endian encoding, in ms)
-04 Level at end of attack. Signed byte.
-05-06 Duration of fade.
-07 Level at end of fade.
-
-*** Magnitude ***
-OP= 03
-LEN= 03
-00-01 Address
-02 Level. Signed byte.
-
-*** Periodicity ***
-OP= 04
-LEN= 07
-00-01 Address
-02 Magnitude. Signed byte.
-03 Offset. Signed byte.
-04 Phase. Val 00 = 0 deg, Val 40 = 90 degs.
-05-06 Period (little endian encoding, in ms)
-
-** Interactive parameters **
-OP= 05
-LEN= 0a
-00-01 Address
-02 Positive Coeff
-03 Negative Coeff
-04+05 Offset (center)
-06+07 Dead band (Val 01F4 = 5000 (decimal))
-08 Positive saturation (Val 0a = 1000 (decimal) Val 64 = 10000 (decimal))
-09 Negative saturation
-
-The encoding is a bit funny here: For coeffs, these are signed values. The
-maximum value is 64 (100 decimal), the min is 9c.
-For the offset, the minimum value is FE0C, the maximum value is 01F4.
-For the deadband, the minimum value is 0, the max is 03E8.
-
-** Controls **
-OP= 41
-LEN= 03
-00 Channel
-01 Start/Stop
- Val 00: Stop
- Val 01: Start and play once.
- Val 41: Start and play n times (See byte 02 below)
-02 Number of iterations n.
-
-** Init **
-
-*** Querying features ***
-OP= ff
-Query command. Length varies according to the query type.
-The general format of this packet is:
-ff 01 QUERY [INDEX] CHECKSUM
-reponses are of the same form:
-FF LEN QUERY VALUE_QUERIED CHECKSUM2
-where LEN = 1 + length(VALUE_QUERIED)
-
-**** Query ram size ****
-QUERY = 42 ('B'uffer size)
-The device should reply with the same packet plus two additionnal bytes
-containing the size of the memory:
-ff 03 42 03 e8 CS would mean that the device has 1000 bytes of ram available.
-
-**** Query number of effects ****
-QUERY = 4e ('N'umber of effects)
-The device should respond by sending the number of effects that can be played
-at the same time (one byte)
-ff 02 4e 14 CS would stand for 20 effects.
-
-**** Vendor's id ****
-QUERY = 4d ('M'anufacturer)
-Query the vendors'id (2 bytes)
-
-**** Product id *****
-QUERY = 50 ('P'roduct)
-Query the product id (2 bytes)
-
-**** Open device ****
-QUERY = 4f ('O'pen)
-No data returned.
-
-**** Close device *****
-QUERY = 43 ('C')lose
-No data returned.
-
-**** Query effect ****
-QUERY = 45 ('E')
-Send effect type.
-Returns nonzero if supported (2 bytes)
-
-**** Firmware Version ****
-QUERY = 56 ('V'ersion)
-Sends back 3 bytes - major, minor, subminor
-
-*** Initialisation of the device ***
-
-**** Set Control ****
-!!! Device dependent, can be different on different models !!!
-OP= 40 <idx> <val> [<val>]
-LEN= 2 or 3
-00 Idx
- Idx 00 Set dead zone (0..2048)
- Idx 01 Ignore Deadman sensor (0..1)
- Idx 02 Enable comm watchdog (0..1)
- Idx 03 Set the strength of the spring (0..100)
- Idx 04 Enable or disable the spring (0/1)
- Idx 05 Set axis saturation threshold (0..2048)
-
-**** Set Effect State ****
-OP= 42 <val>
-LEN= 1
-00 State
- Bit 3 Pause force feedback
- Bit 2 Enable force feedback
- Bit 0 Stop all effects
-
-**** Set overall gain ****
-OP= 43 <val>
-LEN= 1
-00 Gain
- Val 00 = 0%
- Val 40 = 50%
- Val 80 = 100%
-
-** Parameter memory **
-
-Each device has a certain amount of memory to store parameters of effects.
-The amount of RAM may vary, I encountered values from 200 to 1000 bytes. Below
-is the amount of memory apparently needed for every set of parameters:
- - period : 0c
- - magnitude : 02
- - attack and fade : 0e
- - interactive : 08
-
-** Appendix: How to study the protocol ? **
-
-1. Generate effects using the force editor provided with the DirectX SDK, or use Immersion Studio (freely available at their web site in the developer section: www.immersion.com)
-2. Start a soft spying RS232 or USB (depending on where you connected your joystick/wheel). I used ComPortSpy from fCoder (alpha version!)
-3. Play the effect, and watch what happens on the spy screen.
-
-A few words about ComPortSpy:
-At first glance, this soft seems, hum, well... buggy. In fact, data appear with a few seconds latency. Personnaly, I restart it every time I play an effect.
-Remember it's free (as in free beer) and alpha!
-
-** URLS **
-Check www.immerse.com for Immersion Studio, and www.fcoder.com for ComPortSpy.
-
-** Author of this document **
-Johann Deneux <deneux@ifrance.com>
-Home page at http://www.esil.univ-mrs.fr/~jdeneux/projects/ff/
-
-Additions by Vojtech Pavlik.
-
-I-Force is trademark of Immersion Corp.
+** Introduction +This document describes what I managed to discover about the protocol used to +specify force effects to I-Force 2.0 devices. None of this information comes +from Immerse. That's why you should not trust what is written in this +document. This document is intended to help understanding the protocol. +This is not a reference. Comments and corrections are welcome. To contact me, +send an email to: deneux@ifrance.com + +** WARNING ** +I may not be held responsible for any dammage or harm caused if you try to +send data to your I-Force device based on what you read in this document. + +** Preliminary Notes: +All values are hexadecimal with big-endian encoding (msb on the left). Beware, +values inside packets are encoded using little-endian. Bytes whose roles are +unknown are marked ??? Information that needs deeper inspection is marked (?) + +** General form of a packet ** +This is how packets look when the device uses the rs232 to communicate. +2B OP LEN DATA CS +CS is the checksum. It is equal to the exclusive or of all bytes. + +When using USB: +OP DATA +The 2B, LEN and CS fields have disappeared, probably because USB handles frames and +data corruption is handled or unsignificant. + +First, I describe effects that are sent by the device to the computer + +** Device input state +This packet is used to indicate the state of each button and the value of each +axis +OP= 01 for a joystick, 03 for a wheel +LEN= Varies from device to device +00 X-Axis lsb +01 X-Axis msb +02 Y-Axis lsb, or gas pedal for a wheel +03 Y-Axis msb, or brake pedal for a wheel +04 Throttle +05 Buttons +06 Lower 4 bits: Buttons + Upper 4 bits: Hat +07 Rudder + +** Device effects states +OP= 02 +LEN= Varies +00 ? Bit 1 (Value 2) is the value of the deadman switch +01 Bit 8 is set if the effect is playing. Bits 0 to 7 are the effect id. +02 ?? +03 Address of parameter block changed (lsb) +04 Address of parameter block changed (msb) +05 Address of second parameter block changed (lsb) +... depending on the number of parameter blocks updated + +** Force effect ** +OP= 01 +LEN= 0e +00 Channel (when playing several effects at the same time, each must be assigned a channel) +01 Wave form + Val 00 Constant + Val 20 Square + Val 21 Triangle + Val 22 Sine + Val 23 Sawtooth up + Val 24 Sawtooth down + Val 40 Spring (Force = f(pos)) + Val 41 Friction (Force = f(velocity)) and Inertia (Force = f(acceleration)) + + +02 Axes affected and trigger + Bits 4-7: Val 2 = effect along one axis. Byte 05 indicates direction + Val 4 = X axis only. Byte 05 must contain 5a + Val 8 = Y axis only. Byte 05 must contain b4 + Val c = X and Y axes. Bytes 05 must contain 60 + Bits 0-3: Val 0 = No trigger + Val x+1 = Button x triggers the effect + When the whole byte is 0, cancel the previously set trigger + +03-04 Duration of effect (little endian encoding, in ms) + +05 Direction of effect, if applicable. Else, see 02 for value to assign. + +06-07 Minimum time between triggering. + +08-09 Address of periodicity or magnitude parameters +0a-0b Address of attack and fade parameters, or ffff if none. +*or* +08-09 Address of interactive parameters for X-axis, or ffff if not applicable +0a-0b Address of interactive parameters for Y-axis, or ffff if not applicable + +0c-0d Delay before execution of effect (little endian encoding, in ms) + + +** Time based parameters ** + +*** Attack and fade *** +OP= 02 +LEN= 08 +00-01 Address where to store the parameteres +02-03 Duration of attack (little endian encoding, in ms) +04 Level at end of attack. Signed byte. +05-06 Duration of fade. +07 Level at end of fade. + +*** Magnitude *** +OP= 03 +LEN= 03 +00-01 Address +02 Level. Signed byte. + +*** Periodicity *** +OP= 04 +LEN= 07 +00-01 Address +02 Magnitude. Signed byte. +03 Offset. Signed byte. +04 Phase. Val 00 = 0 deg, Val 40 = 90 degs. +05-06 Period (little endian encoding, in ms) + +** Interactive parameters ** +OP= 05 +LEN= 0a +00-01 Address +02 Positive Coeff +03 Negative Coeff +04+05 Offset (center) +06+07 Dead band (Val 01F4 = 5000 (decimal)) +08 Positive saturation (Val 0a = 1000 (decimal) Val 64 = 10000 (decimal)) +09 Negative saturation + +The encoding is a bit funny here: For coeffs, these are signed values. The +maximum value is 64 (100 decimal), the min is 9c. +For the offset, the minimum value is FE0C, the maximum value is 01F4. +For the deadband, the minimum value is 0, the max is 03E8. + +** Controls ** +OP= 41 +LEN= 03 +00 Channel +01 Start/Stop + Val 00: Stop + Val 01: Start and play once. + Val 41: Start and play n times (See byte 02 below) +02 Number of iterations n. + +** Init ** + +*** Querying features *** +OP= ff +Query command. Length varies according to the query type. +The general format of this packet is: +ff 01 QUERY [INDEX] CHECKSUM +reponses are of the same form: +FF LEN QUERY VALUE_QUERIED CHECKSUM2 +where LEN = 1 + length(VALUE_QUERIED) + +**** Query ram size **** +QUERY = 42 ('B'uffer size) +The device should reply with the same packet plus two additionnal bytes +containing the size of the memory: +ff 03 42 03 e8 CS would mean that the device has 1000 bytes of ram available. + +**** Query number of effects **** +QUERY = 4e ('N'umber of effects) +The device should respond by sending the number of effects that can be played +at the same time (one byte) +ff 02 4e 14 CS would stand for 20 effects. + +**** Vendor's id **** +QUERY = 4d ('M'anufacturer) +Query the vendors'id (2 bytes) + +**** Product id ***** +QUERY = 50 ('P'roduct) +Query the product id (2 bytes) + +**** Open device **** +QUERY = 4f ('O'pen) +No data returned. + +**** Close device ***** +QUERY = 43 ('C')lose +No data returned. + +**** Query effect **** +QUERY = 45 ('E') +Send effect type. +Returns nonzero if supported (2 bytes) + +**** Firmware Version **** +QUERY = 56 ('V'ersion) +Sends back 3 bytes - major, minor, subminor + +*** Initialisation of the device *** + +**** Set Control **** +!!! Device dependent, can be different on different models !!! +OP= 40 <idx> <val> [<val>] +LEN= 2 or 3 +00 Idx + Idx 00 Set dead zone (0..2048) + Idx 01 Ignore Deadman sensor (0..1) + Idx 02 Enable comm watchdog (0..1) + Idx 03 Set the strength of the spring (0..100) + Idx 04 Enable or disable the spring (0/1) + Idx 05 Set axis saturation threshold (0..2048) + +**** Set Effect State **** +OP= 42 <val> +LEN= 1 +00 State + Bit 3 Pause force feedback + Bit 2 Enable force feedback + Bit 0 Stop all effects + +**** Set overall gain **** +OP= 43 <val> +LEN= 1 +00 Gain + Val 00 = 0% + Val 40 = 50% + Val 80 = 100% + +** Parameter memory ** + +Each device has a certain amount of memory to store parameters of effects. +The amount of RAM may vary, I encountered values from 200 to 1000 bytes. Below +is the amount of memory apparently needed for every set of parameters: + - period : 0c + - magnitude : 02 + - attack and fade : 0e + - interactive : 08 + +** Appendix: How to study the protocol ? ** + +1. Generate effects using the force editor provided with the DirectX SDK, or use Immersion Studio (freely available at their web site in the developer section: www.immersion.com) +2. Start a soft spying RS232 or USB (depending on where you connected your joystick/wheel). I used ComPortSpy from fCoder (alpha version!) +3. Play the effect, and watch what happens on the spy screen. + +A few words about ComPortSpy: +At first glance, this soft seems, hum, well... buggy. In fact, data appear with a few seconds latency. Personnaly, I restart it every time I play an effect. +Remember it's free (as in free beer) and alpha! + +** URLS ** +Check www.immerse.com for Immersion Studio, and www.fcoder.com for ComPortSpy. + +** Author of this document ** +Johann Deneux <deneux@ifrance.com> +Home page at http://www.esil.univ-mrs.fr/~jdeneux/projects/ff/ + +Additions by Vojtech Pavlik. + +I-Force is trademark of Immersion Corp. diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index f791840..73c5f1f 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -882,7 +882,7 @@ static u32 handle_block_output(int fd, const struct iovec *iov, * of the block file (possibly extending it). */ if (off + len > device_len) { /* Trim it back to the correct length */ - ftruncate(dev->fd, device_len); + ftruncate64(dev->fd, device_len); /* Die, bad Guest, die. */ errx(1, "Write past end %llu+%u", off, len); } |