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Commit 7ada60e3 authored by Kristian Høgsberg's avatar Kristian Høgsberg Committed by Stefan Richter
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firewire: Document userspace ioctl interface. 

The isochronous packet format is still not documented, but this
is a good first step.
Signed-off-by: default avatarKristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (format, wording)
parent 5cd54c94
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Showing with 264 additions and 33 deletions
include/linux/firewire-cdev.h
View file @ 7ada60e3
......@@ -30,16 +30,38 @@
#define FW_CDEV_EVENT_REQUEST 0x02
#define FW_CDEV_EVENT_ISO_INTERRUPT 0x03
/* The 'closure' fields are for user space to use. Data passed in the
* 'closure' field for a request will be returned in the corresponding
* event. It's a 64-bit type so that it's a fixed size type big
* enough to hold a pointer on all platforms. */
/**
* struct fw_cdev_event_common - Common part of all fw_cdev_event_ types
* @closure: For arbitrary use by userspace
* @type: Discriminates the fw_cdev_event_ types
*
* This struct may be used to access generic members of all fw_cdev_event_
* types regardless of the specific type.
*
* Data passed in the @closure field for a request will be returned in the
* corresponding event. It is big enough to hold a pointer on all platforms.
* The ioctl used to set @closure depends on the @type of event.
*/
struct fw_cdev_event_common {
__u64 closure;
__u32 type;
};
/**
* struct fw_cdev_event_bus_reset - Sent when a bus reset occurred
* @closure: See &fw_cdev_event_common; set by %FW_CDEV_IOC_GET_INFO ioctl
* @type: See &fw_cdev_event_common; always %FW_CDEV_EVENT_BUS_RESET
* @node_id: New node ID of this node
* @local_node_id: Node ID of the local node, i.e. of the controller
* @bm_node_id: Node ID of the bus manager
* @irm_node_id: Node ID of the iso resource manager
* @root_node_id: Node ID of the root node
* @generation: New bus generation
*
* This event is sent when the bus the device belongs to goes through a bus
* reset. It provides information about the new bus configuration, such as
* new node ID for this device, new root ID, and others.
*/
struct fw_cdev_event_bus_reset {
__u64 closure;
__u32 type;
......@@ -51,6 +73,20 @@ struct fw_cdev_event_bus_reset {
__u32 generation;
};
/**
* struct fw_cdev_event_response - Sent when a response packet was received
* @closure: See &fw_cdev_event_common;
* set by %FW_CDEV_IOC_SEND_REQUEST ioctl
* @type: See &fw_cdev_event_common; always %FW_CDEV_EVENT_RESPONSE
* @rcode: Response code returned by the remote node
* @length: Data length, i.e. the response's payload size in bytes
* @data: Payload data, if any
*
* This event is sent when the stack receives a response to an outgoing request
* sent by %FW_CDEV_IOC_SEND_REQUEST ioctl. The payload data for responses
* carrying data (read and lock responses) follows immediately and can be
* accessed through the @data field.
*/
struct fw_cdev_event_response {
__u64 closure;
__u32 type;
......@@ -59,6 +95,25 @@ struct fw_cdev_event_response {
__u32 data[0];
};
/**
* struct fw_cdev_event_request - Sent on incoming request to an address region
* @closure: See &fw_cdev_event_common; set by %FW_CDEV_IOC_ALLOCATE ioctl
* @type: See &fw_cdev_event_common; always %FW_CDEV_EVENT_REQUEST
* @tcode: Transaction code of the incoming request
* @offset: The offset into the 48-bit per-node address space
* @handle: Reference to the kernel-side pending request
* @length: Data length, i.e. the request's payload size in bytes
* @data: Incoming data, if any
*
* This event is sent when the stack receives an incoming request to an address
* region registered using the %FW_CDEV_IOC_ALLOCATE ioctl. The request is
* guaranteed to be completely contained in the specified region. Userspace is
* responsible for sending the response by %FW_CDEV_IOC_SEND_RESPONSE ioctl,
* using the same @handle.
*
* The payload data for requests carrying data (write and lock requests)
* follows immediately and can be accessed through the @data field.
*/
struct fw_cdev_event_request {
__u64 closure;
__u32 type;
......@@ -69,14 +124,39 @@ struct fw_cdev_event_request {
__u32 data[0];
};
/**
* struct fw_cdev_event_iso_interrupt - Sent when an iso packet was completed
* @closure: See &fw_cdev_event_common;
* set by %FW_CDEV_CREATE_ISO_CONTEXT ioctl
* @type: See &fw_cdev_event_common; always %FW_CDEV_EVENT_ISO_INTERRUPT
* @cycle: Cycle counter of the interrupt packet
* @header_length: Total length of following headers, in bytes
* @header: Stripped headers, if any
*
* This event is sent when the controller has completed an &fw_cdev_iso_packet
* with the %FW_CDEV_ISO_INTERRUPT bit set. In the receive case, the headers
* stripped of all packets up until and including the interrupt packet are
* returned in the @header field.
*/
struct fw_cdev_event_iso_interrupt {
__u64 closure;
__u32 type;
__u32 cycle;
__u32 header_length; /* Length in bytes of following headers. */
__u32 header_length;
__u32 header[0];
};
/**
* union fw_cdev_event - Convenience union of fw_cdev_event_ types
* @common: Valid for all types
* @bus_reset: Valid if @common.type == %FW_CDEV_EVENT_BUS_RESET
* @response: Valid if @common.type == %FW_CDEV_EVENT_RESPONSE
* @request: Valid if @common.type == %FW_CDEV_EVENT_REQUEST
* @iso_interrupt: Valid if @common.type == %FW_CDEV_EVENT_ISO_INTERRUPT
*
* Convenience union for userspace use. Events could be read(2) into a char
* buffer and then cast to this union for further processing.
*/
union fw_cdev_event {
struct fw_cdev_event_common common;
struct fw_cdev_event_bus_reset bus_reset;
......@@ -105,35 +185,47 @@ union fw_cdev_event {
*/
#define FW_CDEV_VERSION 1
/**
* struct fw_cdev_get_info - General purpose information ioctl
* @version: The version field is just a running serial number.
* We never break backwards compatibility, but may add more
* structs and ioctls in later revisions.
* @rom_length: If @rom is non-zero, at most rom_length bytes of configuration
* ROM will be copied into that user space address. In either
* case, @rom_length is updated with the actual length of the
* configuration ROM.
* @rom: If non-zero, address of a buffer to be filled by a copy of the
* local node's configuration ROM
* @bus_reset: If non-zero, address of a buffer to be filled by a
* &struct fw_cdev_event_bus_reset with the current state
* of the bus. This does not cause a bus reset to happen.
* @bus_reset_closure: Value of &closure in this and subsequent bus reset events
* @card: The index of the card this device belongs to
*/
struct fw_cdev_get_info {
/* The version field is just a running serial number. We
* never break backwards compatibility. Userspace passes in
* the version it expects and the kernel passes back the
* highest version it can provide. Even if the structs in
* this interface are extended in a later version, the kernel
* will not copy back more data than what was present in the
* interface version userspace expects. */
__u32 version;
/* If non-zero, at most rom_length bytes of config rom will be
* copied into that user space address. In either case,
* rom_length is updated with the actual length of the config
* rom. */
__u32 rom_length;
__u64 rom;
/* If non-zero, a fw_cdev_event_bus_reset struct will be
* copied here with the current state of the bus. This does
* not cause a bus reset to happen. The value of closure in
* this and sub-sequent bus reset events is set to
* bus_reset_closure. */
__u64 bus_reset;
__u64 bus_reset_closure;
/* The index of the card this devices belongs to. */
__u32 card;
};
/**
* struct fw_cdev_send_request - Send an asynchronous request packet
* @tcode: Transaction code of the request
* @length: Length of outgoing payload, in bytes
* @offset: 48-bit offset at destination node
* @closure: Passed back to userspace in the response event
* @data: Userspace pointer to payload
* @generation: The bus generation where packet is valid
*
* Send a request to the device. This ioctl implements all outgoing requests.
* Both quadlet and block request specify the payload as a pointer to the data
* in the @data field. Once the transaction completes, the kernel writes an
* &fw_cdev_event_request event back. The @closure field is passed back to
* user space in the response event.
*/
struct fw_cdev_send_request {
__u32 tcode;
__u32 length;
......@@ -143,6 +235,19 @@ struct fw_cdev_send_request {
__u32 generation;
};
/**
* struct fw_cdev_send_response - Send an asynchronous response packet
* @rcode: Response code as determined by the userspace handler
* @length: Length of outgoing payload, in bytes
* @data: Userspace pointer to payload
* @handle: The handle from the &fw_cdev_event_request
*
* Send a response to an incoming request. By setting up an address range using
* the %FW_CDEV_IOC_ALLOCATE ioctl, userspace can listen for incoming requests. An
* incoming request will generate an %FW_CDEV_EVENT_REQUEST, and userspace must
* send a reply using this ioctl. The event has a handle to the kernel-side
* pending transaction, which should be used with this ioctl.
*/
struct fw_cdev_send_response {
__u32 rcode;
__u32 length;
......@@ -150,6 +255,21 @@ struct fw_cdev_send_response {
__u32 handle;
};
/**
* struct fw_cdev_allocate - Allocate a CSR address range
* @offset: Start offset of the address range
* @closure: To be passed back to userspace in request events
* @length: Length of the address range, in bytes
* @handle: Handle to the allocation, written by the kernel
*
* Allocate an address range in the 48-bit address space on the local node
* (the controller). This allows userspace to listen for requests with an
* offset within that address range. When the kernel receives a request
* within the range, an &fw_cdev_event_request event will be written back.
* The @closure field is passed back to userspace in the response event.
* The @handle field is an out parameter, returning a handle to the allocated
* range to be used for later deallocation of the range.
*/
struct fw_cdev_allocate {
__u64 offset;
__u64 closure;
......@@ -157,6 +277,11 @@ struct fw_cdev_allocate {
__u32 handle;
};
/**
* struct fw_cdev_deallocate - Free an address range allocation
* @handle: Handle to the address range, as returned by the kernel when the
* range was allocated
*/
struct fw_cdev_deallocate {
__u32 handle;
};
......@@ -164,10 +289,41 @@ struct fw_cdev_deallocate {
#define FW_CDEV_LONG_RESET 0
#define FW_CDEV_SHORT_RESET 1
/**
* struct fw_cdev_initiate_bus_reset - Initiate a bus reset
* @type: %FW_CDEV_SHORT_RESET or %FW_CDEV_LONG_RESET
*
* Initiate a bus reset for the bus this device is on. The bus reset can be
* either the original (long) bus reset or the arbitrated (short) bus reset
* introduced in 1394a-2000.
*/
struct fw_cdev_initiate_bus_reset {
__u32 type;
__u32 type; /* FW_CDEV_SHORT_RESET or FW_CDEV_LONG_RESET */
};
/**
* struct fw_cdev_add_descriptor - Add contents to the local node's config ROM
* @immediate: If non-zero, immediate key to insert before pointer
* @key: Upper 8 bits of root directory pointer
* @data: Userspace pointer to contents of descriptor block
* @length: Length of descriptor block data, in bytes
* @handle: Handle to the descriptor, written by the kernel
*
* Add a descriptor block and optionally a preceding immediate key to the local
* node's configuration ROM.
*
* The @key field specifies the upper 8 bits of the descriptor root directory
* pointer and the @data and @length fields specify the contents. The @key
* should be of the form 0xXX000000. The offset part of the root directory entry
* will be filled in by the kernel.
*
* If not 0, the @immediate field specifies an immediate key which will be
* inserted before the root directory pointer.
*
* If successful, the kernel adds the descriptor and writes back a handle to the
* kernel-side object to be used for later removal of the descriptor block and
* immediate key.
*/
struct fw_cdev_add_descriptor {
__u32 immediate;
__u32 key;
......@@ -176,6 +332,14 @@ struct fw_cdev_add_descriptor {
__u32 handle;
};
/**
* struct fw_cdev_remove_descriptor - Remove contents from the configuration ROM
* @handle: Handle to the descriptor, as returned by the kernel when the
* descriptor was added
*
* Remove a descriptor block and accompanying immediate key from the local
* node's configuration ROM.
*/
struct fw_cdev_remove_descriptor {
__u32 handle;
};
......@@ -183,12 +347,24 @@ struct fw_cdev_remove_descriptor {
#define FW_CDEV_ISO_CONTEXT_TRANSMIT 0
#define FW_CDEV_ISO_CONTEXT_RECEIVE 1
#define FW_CDEV_ISO_CONTEXT_MATCH_TAG0 1
#define FW_CDEV_ISO_CONTEXT_MATCH_TAG1 2
#define FW_CDEV_ISO_CONTEXT_MATCH_TAG2 4
#define FW_CDEV_ISO_CONTEXT_MATCH_TAG3 8
#define FW_CDEV_ISO_CONTEXT_MATCH_ALL_TAGS 15
/**
* struct fw_cdev_create_iso_context - Create a context for isochronous IO
* @type: %FW_CDEV_ISO_CONTEXT_TRANSMIT or %FW_CDEV_ISO_CONTEXT_RECEIVE
* @header_size: Header size to strip for receive contexts
* @channel: Channel to bind to
* @speed: Speed to transmit at
* @closure: To be returned in &fw_cdev_event_iso_interrupt
* @handle: Handle to context, written back by kernel
*
* Prior to sending or receiving isochronous I/O, a context must be created.
* The context records information about the transmit or receive configuration
* and typically maps to an underlying hardware resource. A context is set up
* for either sending or receiving. It is bound to a specific isochronous
* channel.
*
* If a context was successfully created, the kernel writes back a handle to the
* context, which must be passed in for subsequent operations on that context.
*/
struct fw_cdev_create_iso_context {
__u32 type;
__u32 header_size;
......@@ -201,15 +377,49 @@ struct fw_cdev_create_iso_context {
#define FW_CDEV_ISO_PAYLOAD_LENGTH(v) (v)
#define FW_CDEV_ISO_INTERRUPT (1 << 16)
#define FW_CDEV_ISO_SKIP (1 << 17)
#define FW_CDEV_ISO_SYNC (1 << 17)
#define FW_CDEV_ISO_TAG(v) ((v) << 18)
#define FW_CDEV_ISO_SY(v) ((v) << 20)
#define FW_CDEV_ISO_HEADER_LENGTH(v) ((v) << 24)
/**
* struct fw_cdev_iso_packet - Isochronous packet
* @control: Contains the header length (8 uppermost bits), the sy field
* (4 bits), the tag field (2 bits), a sync flag (1 bit),
* a skip flag (1 bit), an interrupt flag (1 bit), and the
* payload length (16 lowermost bits)
* @header: Header and payload
*
* &struct fw_cdev_iso_packet is used to describe isochronous packet queues.
*
* Use the FW_CDEV_ISO_ macros to fill in @control. The sy and tag fields are
* specified by IEEE 1394a and IEC 61883.
*
* FIXME - finish this documentation
*/
struct fw_cdev_iso_packet {
__u32 control;
__u32 header[0];
};
/**
* struct fw_cdev_queue_iso - Queue isochronous packets for I/O
* @packets: Userspace pointer to packet data
* @data: Pointer into mmap()'ed payload buffer
* @size: Size of packet data in bytes
* @handle: Isochronous context handle
*
* Queue a number of isochronous packets for reception or transmission.
* This ioctl takes a pointer to an array of &fw_cdev_iso_packet structs,
* which describe how to transmit from or receive into a contiguous region
* of a mmap()'ed payload buffer. As part of the packet descriptors,
* a series of headers can be supplied, which will be prepended to the
* payload during DMA.
*
* The kernel may or may not queue all packets, but will write back updated
* values of the @packets, @data and @size fields, so the ioctl can be
* resubmitted easily.
*/
struct fw_cdev_queue_iso {
__u64 packets;
__u64 data;
......@@ -217,6 +427,23 @@ struct fw_cdev_queue_iso {
__u32 handle;
};
#define FW_CDEV_ISO_CONTEXT_MATCH_TAG0 1
#define FW_CDEV_ISO_CONTEXT_MATCH_TAG1 2
#define FW_CDEV_ISO_CONTEXT_MATCH_TAG2 4
#define FW_CDEV_ISO_CONTEXT_MATCH_TAG3 8
#define FW_CDEV_ISO_CONTEXT_MATCH_ALL_TAGS 15
/**
* struct fw_cdev_start_iso - Start an isochronous transmission or reception
* @cycle: Cycle in which to start I/O. If @cycle is greater than or
* equal to 0, the I/O will start on that cycle.
* @sync: Determines the value to wait for for receive packets that have
* the %FW_CDEV_ISO_SYNC bit set
* @tags: Tag filter bit mask. Only valid for isochronous reception.
* Determines the tag values for which packets will be accepted.
* Use FW_CDEV_ISO_CONTEXT_MATCH_ macros to set @tags.
* @handle: Isochronous context handle within which to transmit or receive
*/
struct fw_cdev_start_iso {
__s32 cycle;
__u32 sync;
......@@ -224,6 +451,10 @@ struct fw_cdev_start_iso {
__u32 handle;
};
/**
* struct fw_cdev_stop_iso - Stop an isochronous transmission or reception
* @handle: Handle of isochronous context to stop
*/
struct fw_cdev_stop_iso {
__u32 handle;
};
......
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