Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire: document the sysfs ABIs
firewire: cdev: ABI documentation enhancements
firewire: cdev: prevent race between first get_info ioctl and bus reset event queuing
firewire: cdev: return -ENOTTY for unimplemented ioctls, not -EINVAL
firewire: ohci: skip soft reset retries after card ejection
firewire: ohci: fix PHY reg access after card ejection
firewire: ohci: add a comment on PHY reg access serialization
firewire: ohci: reduce potential context_stop latency
firewire: ohci: remove superfluous posted write flushes
firewire: net: replacing deprecated __attribute__((packed)) with __packed
diff --git a/Documentation/ABI/stable/firewire-cdev b/Documentation/ABI/stable/firewire-cdev
new file mode 100644
index 0000000..16d0308
--- /dev/null
+++ b/Documentation/ABI/stable/firewire-cdev
@@ -0,0 +1,103 @@
+What: /dev/fw[0-9]+
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: linux1394-devel@lists.sourceforge.net
+Description:
+ The character device files /dev/fw* are the interface between
+ firewire-core and IEEE 1394 device drivers implemented in
+ userspace. The ioctl(2)- and read(2)-based ABI is defined and
+ documented in <linux/firewire-cdev.h>.
+
+ This ABI offers most of the features which firewire-core also
+ exposes to kernelspace IEEE 1394 drivers.
+
+ Each /dev/fw* is associated with one IEEE 1394 node, which can
+ be remote or local nodes. Operations on a /dev/fw* file have
+ different scope:
+ - The 1394 node which is associated with the file:
+ - Asynchronous request transmission
+ - Get the Configuration ROM
+ - Query node ID
+ - Query maximum speed of the path between this node
+ and local node
+ - The 1394 bus (i.e. "card") to which the node is attached to:
+ - Isochronous stream transmission and reception
+ - Asynchronous stream transmission and reception
+ - Asynchronous broadcast request transmission
+ - PHY packet transmission and reception
+ - Allocate, reallocate, deallocate isochronous
+ resources (channels, bandwidth) at the bus's IRM
+ - Query node IDs of local node, root node, IRM, bus
+ manager
+ - Query cycle time
+ - Bus reset initiation, bus reset event reception
+ - All 1394 buses:
+ - Allocation of IEEE 1212 address ranges on the local
+ link layers, reception of inbound requests to such
+ an address range, asynchronous response transmission
+ to inbound requests
+ - Addition of descriptors or directories to the local
+ nodes' Configuration ROM
+
+ Due to the different scope of operations and in order to let
+ userland implement different access permission models, some
+ operations are restricted to /dev/fw* files that are associated
+ with a local node:
+ - Addition of descriptors or directories to the local
+ nodes' Configuration ROM
+ - PHY packet transmission and reception
+
+ A /dev/fw* file remains associated with one particular node
+ during its entire life time. Bus topology changes, and hence
+ node ID changes, are tracked by firewire-core. ABI users do not
+ need to be aware of topology.
+
+ The following file operations are supported:
+
+ open(2)
+ Currently the only useful flags are O_RDWR.
+
+ ioctl(2)
+ Initiate various actions. Some take immediate effect, others
+ are performed asynchronously while or after the ioctl returns.
+ See the inline documentation in <linux/firewire-cdev.h> for
+ descriptions of all ioctls.
+
+ poll(2), select(2), epoll_wait(2) etc.
+ Watch for events to become available to be read.
+
+ read(2)
+ Receive various events. There are solicited events like
+ outbound asynchronous transaction completion or isochronous
+ buffer completion, and unsolicited events such as bus resets,
+ request reception, or PHY packet reception. Always use a read
+ buffer which is large enough to receive the largest event that
+ could ever arrive. See <linux/firewire-cdev.h> for descriptions
+ of all event types and for which ioctls affect reception of
+ events.
+
+ mmap(2)
+ Allocate a DMA buffer for isochronous reception or transmission
+ and map it into the process address space. The arguments should
+ be used as follows: addr = NULL, length = the desired buffer
+ size, i.e. number of packets times size of largest packet,
+ prot = at least PROT_READ for reception and at least PROT_WRITE
+ for transmission, flags = MAP_SHARED, fd = the handle to the
+ /dev/fw*, offset = 0.
+
+ Isochronous reception works in packet-per-buffer fashion except
+ for multichannel reception which works in buffer-fill mode.
+
+ munmap(2)
+ Unmap the isochronous I/O buffer from the process address space.
+
+ close(2)
+ Besides stopping and freeing I/O contexts that were associated
+ with the file descriptor, back out any changes to the local
+ nodes' Configuration ROM. Deallocate isochronous channels and
+ bandwidth at the IRM that were marked for kernel-assisted
+ re- and deallocation.
+
+Users: libraw1394
+ libdc1394
+ tools like jujuutils, fwhack, ...
diff --git a/Documentation/ABI/stable/sysfs-bus-firewire b/Documentation/ABI/stable/sysfs-bus-firewire
new file mode 100644
index 0000000..3d484e5
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-bus-firewire
@@ -0,0 +1,122 @@
+What: /sys/bus/firewire/devices/fw[0-9]+/
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: linux1394-devel@lists.sourceforge.net
+Description:
+ IEEE 1394 node device attributes.
+ Read-only. Mutable during the node device's lifetime.
+ See IEEE 1212 for semantic definitions.
+
+ config_rom
+ Contents of the Configuration ROM register.
+ Binary attribute; an array of host-endian u32.
+
+ guid
+ The node's EUI-64 in the bus information block of
+ Configuration ROM.
+ Hexadecimal string representation of an u64.
+
+
+What: /sys/bus/firewire/devices/fw[0-9]+/units
+Date: June 2009
+KernelVersion: 2.6.31
+Contact: linux1394-devel@lists.sourceforge.net
+Description:
+ IEEE 1394 node device attribute.
+ Read-only. Mutable during the node device's lifetime.
+ See IEEE 1212 for semantic definitions.
+
+ units
+ Summary of all units present in an IEEE 1394 node.
+ Contains space-separated tuples of specifier_id and
+ version of each unit present in the node. Specifier_id
+ and version are hexadecimal string representations of
+ u24 of the respective unit directory entries.
+ Specifier_id and version within each tuple are separated
+ by a colon.
+
+Users: udev rules to set ownership and access permissions or ACLs of
+ /dev/fw[0-9]+ character device files
+
+
+What: /sys/bus/firewire/devices/fw[0-9]+[.][0-9]+/
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: linux1394-devel@lists.sourceforge.net
+Description:
+ IEEE 1394 unit device attributes.
+ Read-only. Immutable during the unit device's lifetime.
+ See IEEE 1212 for semantic definitions.
+
+ modalias
+ Same as MODALIAS in the uevent at device creation.
+
+ rom_index
+ Offset of the unit directory within the parent device's
+ (node device's) Configuration ROM, in quadlets.
+ Decimal string representation.
+
+
+What: /sys/bus/firewire/devices/*/
+Date: May 2007
+KernelVersion: 2.6.22
+Contact: linux1394-devel@lists.sourceforge.net
+Description:
+ Attributes common to IEEE 1394 node devices and unit devices.
+ Read-only. Mutable during the node device's lifetime.
+ Immutable during the unit device's lifetime.
+ See IEEE 1212 for semantic definitions.
+
+ These attributes are only created if the root directory of an
+ IEEE 1394 node or the unit directory of an IEEE 1394 unit
+ actually contains according entries.
+
+ hardware_version
+ Hexadecimal string representation of an u24.
+
+ hardware_version_name
+ Contents of a respective textual descriptor leaf.
+
+ model
+ Hexadecimal string representation of an u24.
+
+ model_name
+ Contents of a respective textual descriptor leaf.
+
+ specifier_id
+ Hexadecimal string representation of an u24.
+ Mandatory in unit directories according to IEEE 1212.
+
+ vendor
+ Hexadecimal string representation of an u24.
+ Mandatory in the root directory according to IEEE 1212.
+
+ vendor_name
+ Contents of a respective textual descriptor leaf.
+
+ version
+ Hexadecimal string representation of an u24.
+ Mandatory in unit directories according to IEEE 1212.
+
+
+What: /sys/bus/firewire/drivers/sbp2/fw*/host*/target*/*:*:*:*/ieee1394_id
+ formerly
+ /sys/bus/ieee1394/drivers/sbp2/fw*/host*/target*/*:*:*:*/ieee1394_id
+Date: Feb 2004
+KernelVersion: 2.6.4
+Contact: linux1394-devel@lists.sourceforge.net
+Description:
+ SCSI target port identifier and logical unit identifier of a
+ logical unit of an SBP-2 target. The identifiers are specified
+ in SAM-2...SAM-4 annex A. They are persistent and world-wide
+ unique properties the SBP-2 attached target.
+
+ Read-only attribute, immutable during the target's lifetime.
+ Format, as exposed by firewire-sbp2 since 2.6.22, May 2007:
+ Colon-separated hexadecimal string representations of
+ u64 EUI-64 : u24 directory_ID : u16 LUN
+ without 0x prefixes, without whitespace. The former sbp2 driver
+ (removed in 2.6.37 after being superseded by firewire-sbp2) used
+ a somewhat shorter format which was not as close to SAM.
+
+Users: udev rules to create /dev/disk/by-id/ symlinks
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index b1c1177..e6ad3bb 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -253,14 +253,11 @@
init_waitqueue_head(&client->wait);
init_waitqueue_head(&client->tx_flush_wait);
INIT_LIST_HEAD(&client->phy_receiver_link);
+ INIT_LIST_HEAD(&client->link);
kref_init(&client->kref);
file->private_data = client;
- mutex_lock(&device->client_list_mutex);
- list_add_tail(&client->link, &device->client_list);
- mutex_unlock(&device->client_list_mutex);
-
return nonseekable_open(inode, file);
}
@@ -451,15 +448,20 @@
if (ret != 0)
return -EFAULT;
+ mutex_lock(&client->device->client_list_mutex);
+
client->bus_reset_closure = a->bus_reset_closure;
if (a->bus_reset != 0) {
fill_bus_reset_event(&bus_reset, client);
- if (copy_to_user(u64_to_uptr(a->bus_reset),
- &bus_reset, sizeof(bus_reset)))
- return -EFAULT;
+ ret = copy_to_user(u64_to_uptr(a->bus_reset),
+ &bus_reset, sizeof(bus_reset));
}
+ if (ret == 0 && list_empty(&client->link))
+ list_add_tail(&client->link, &client->device->client_list);
- return 0;
+ mutex_unlock(&client->device->client_list_mutex);
+
+ return ret ? -EFAULT : 0;
}
static int add_client_resource(struct client *client,
@@ -1583,7 +1585,7 @@
if (_IOC_TYPE(cmd) != '#' ||
_IOC_NR(cmd) >= ARRAY_SIZE(ioctl_handlers) ||
_IOC_SIZE(cmd) > sizeof(buffer))
- return -EINVAL;
+ return -ENOTTY;
if (_IOC_DIR(cmd) == _IOC_READ)
memset(&buffer, 0, _IOC_SIZE(cmd));
diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
index eced1c2..03a7a85 100644
--- a/drivers/firewire/net.c
+++ b/drivers/firewire/net.c
@@ -7,6 +7,7 @@
*/
#include <linux/bug.h>
+#include <linux/compiler.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/ethtool.h>
@@ -73,7 +74,7 @@
__be32 fifo_lo; /* lo 32bits of sender's FIFO addr */
__be32 sip; /* Sender's IP Address */
__be32 tip; /* IP Address of requested hw addr */
-} __attribute__((packed));
+} __packed;
/* This header format is specific to this driver implementation. */
#define FWNET_ALEN 8
@@ -81,7 +82,7 @@
struct fwnet_header {
u8 h_dest[FWNET_ALEN]; /* destination address */
__be16 h_proto; /* packet type ID field */
-} __attribute__((packed));
+} __packed;
/* IPv4 and IPv6 encapsulation header */
struct rfc2734_header {
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index ebb8973..bcf792f 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -253,7 +253,6 @@
#define OHCI1394_MAX_PHYS_RESP_RETRIES 0x8
#define OHCI1394_REGISTER_SIZE 0x800
-#define OHCI_LOOP_COUNT 500
#define OHCI1394_PCI_HCI_Control 0x40
#define SELF_ID_BUF_SIZE 0x800
#define OHCI_TCODE_PHY_PACKET 0x0e
@@ -514,6 +513,12 @@
reg_read(ohci, OHCI1394_Version);
}
+/*
+ * Beware! read_phy_reg(), write_phy_reg(), update_phy_reg(), and
+ * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
+ * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
+ * directly. Exceptions are intrinsically serialized contexts like pci_probe.
+ */
static int read_phy_reg(struct fw_ohci *ohci, int addr)
{
u32 val;
@@ -522,6 +527,9 @@
reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
for (i = 0; i < 3 + 100; i++) {
val = reg_read(ohci, OHCI1394_PhyControl);
+ if (!~val)
+ return -ENODEV; /* Card was ejected. */
+
if (val & OHCI1394_PhyControl_ReadDone)
return OHCI1394_PhyControl_ReadData(val);
@@ -545,6 +553,9 @@
OHCI1394_PhyControl_Write(addr, val));
for (i = 0; i < 3 + 100; i++) {
val = reg_read(ohci, OHCI1394_PhyControl);
+ if (!~val)
+ return -ENODEV; /* Card was ejected. */
+
if (!(val & OHCI1394_PhyControl_WritePending))
return 0;
@@ -630,7 +641,6 @@
ctx->last_buffer_index = index;
reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
- flush_writes(ctx->ohci);
}
static void ar_context_release(struct ar_context *ctx)
@@ -1002,7 +1012,6 @@
reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
- flush_writes(ctx->ohci);
}
static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
@@ -1202,14 +1211,14 @@
reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
ctx->running = false;
- flush_writes(ctx->ohci);
- for (i = 0; i < 10; i++) {
+ for (i = 0; i < 1000; i++) {
reg = reg_read(ctx->ohci, CONTROL_SET(ctx->regs));
if ((reg & CONTEXT_ACTIVE) == 0)
return;
- mdelay(1);
+ if (i)
+ udelay(10);
}
fw_error("Error: DMA context still active (0x%08x)\n", reg);
}
@@ -1346,12 +1355,10 @@
context_append(ctx, d, z, 4 - z);
- if (ctx->running) {
+ if (ctx->running)
reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
- flush_writes(ohci);
- } else {
+ else
context_run(ctx, 0);
- }
return 0;
}
@@ -1960,14 +1967,18 @@
static int software_reset(struct fw_ohci *ohci)
{
+ u32 val;
int i;
reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
+ for (i = 0; i < 500; i++) {
+ val = reg_read(ohci, OHCI1394_HCControlSet);
+ if (!~val)
+ return -ENODEV; /* Card was ejected. */
- for (i = 0; i < OHCI_LOOP_COUNT; i++) {
- if ((reg_read(ohci, OHCI1394_HCControlSet) &
- OHCI1394_HCControl_softReset) == 0)
+ if (!(val & OHCI1394_HCControl_softReset))
return 0;
+
msleep(1);
}
@@ -2197,7 +2208,9 @@
OHCI1394_LinkControl_rcvPhyPkt);
ar_context_run(&ohci->ar_request_ctx);
- ar_context_run(&ohci->ar_response_ctx); /* also flushes writes */
+ ar_context_run(&ohci->ar_response_ctx);
+
+ flush_writes(ohci);
/* We are ready to go, reset bus to finish initialization. */
fw_schedule_bus_reset(&ohci->card, false, true);
@@ -3129,7 +3142,6 @@
&container_of(base, struct iso_context, base)->context;
reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
- flush_writes(ctx->ohci);
}
static const struct fw_card_driver ohci_driver = {
diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h
index 4ff0988..357dbfc 100644
--- a/include/linux/firewire-cdev.h
+++ b/include/linux/firewire-cdev.h
@@ -30,10 +30,13 @@
#include <linux/types.h>
#include <linux/firewire-constants.h>
+/* available since kernel version 2.6.22 */
#define FW_CDEV_EVENT_BUS_RESET 0x00
#define FW_CDEV_EVENT_RESPONSE 0x01
#define FW_CDEV_EVENT_REQUEST 0x02
#define FW_CDEV_EVENT_ISO_INTERRUPT 0x03
+
+/* available since kernel version 2.6.30 */
#define FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED 0x04
#define FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED 0x05
@@ -120,24 +123,11 @@
/**
* struct fw_cdev_event_request - Old version of &fw_cdev_event_request2
- * @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: See &fw_cdev_event_request2
- * @offset: See &fw_cdev_event_request2
- * @handle: See &fw_cdev_event_request2
- * @length: See &fw_cdev_event_request2
- * @data: See &fw_cdev_event_request2
*
* This event is sent instead of &fw_cdev_event_request2 if the kernel or
- * the client implements ABI version <= 3.
- *
- * Unlike &fw_cdev_event_request2, the sender identity cannot be established,
- * broadcast write requests cannot be distinguished from unicast writes, and
- * @tcode of lock requests is %TCODE_LOCK_REQUEST.
- *
- * Requests to the FCP_REQUEST or FCP_RESPONSE register are responded to as
- * with &fw_cdev_event_request2, except in kernel 2.6.32 and older which send
- * the response packet of the client's %FW_CDEV_IOC_SEND_RESPONSE ioctl.
+ * the client implements ABI version <= 3. &fw_cdev_event_request lacks
+ * essential information; use &fw_cdev_event_request2 instead.
*/
struct fw_cdev_event_request {
__u64 closure;
@@ -452,29 +442,31 @@
* %FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL, and
* %FW_CDEV_IOC_SET_ISO_CHANNELS
*/
-#define FW_CDEV_VERSION 3 /* Meaningless; don't use this macro. */
/**
* struct fw_cdev_get_info - General purpose information ioctl
* @version: The version field is just a running serial number. Both an
* input parameter (ABI version implemented by the client) and
* output parameter (ABI version implemented by the kernel).
- * A client must not fill in an %FW_CDEV_VERSION defined from an
- * included kernel header file but the actual version for which
- * the client was implemented. This is necessary for forward
- * compatibility. We never break backwards compatibility, but
- * may add more structs, events, and ioctls in later revisions.
- * @rom_length: If @rom is non-zero, at most rom_length bytes of configuration
+ * A client shall fill in the ABI @version for which the client
+ * was implemented. This is necessary for forward compatibility.
+ * @rom_length: If @rom is non-zero, up to @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.
+ * Configuration ROM.
* @rom: If non-zero, address of a buffer to be filled by a copy of the
- * device's configuration ROM
+ * device'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
+ *
+ * The %FW_CDEV_IOC_GET_INFO ioctl is usually the very first one which a client
+ * performs right after it opened a /dev/fw* file.
+ *
+ * As a side effect, reception of %FW_CDEV_EVENT_BUS_RESET events to be read(2)
+ * is started by this ioctl.
*/
struct fw_cdev_get_info {
__u32 version;
@@ -612,7 +604,7 @@
* @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.
+ * 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
@@ -627,9 +619,9 @@
* 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. The kernel will also generate a bus reset to signal the
- * change of the configuration ROM to other nodes.
+ * change of the Configuration ROM to other nodes.
*
- * This ioctl affects the configuration ROMs of all local nodes.
+ * This ioctl affects the Configuration ROMs of all local nodes.
* The ioctl only succeeds on device files which represent a local node.
*/
struct fw_cdev_add_descriptor {
@@ -641,13 +633,13 @@
};
/**
- * struct fw_cdev_remove_descriptor - Remove contents from the configuration ROM
+ * 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
- * nodes' configuration ROMs. The kernel will also generate a bus reset to
- * signal the change of the configuration ROM to other nodes.
+ * nodes' Configuration ROMs. The kernel will also generate a bus reset to
+ * signal the change of the Configuration ROM to other nodes.
*/
struct fw_cdev_remove_descriptor {
__u32 handle;
@@ -863,13 +855,8 @@
* @local_time: system time, in microseconds since the Epoch
* @cycle_timer: Cycle Time register contents
*
- * The %FW_CDEV_IOC_GET_CYCLE_TIMER ioctl reads the isochronous cycle timer
- * and also the system clock (%CLOCK_REALTIME). This allows to express the
- * receive time of an isochronous packet as a system time.
- *
- * @cycle_timer consists of 7 bits cycleSeconds, 13 bits cycleCount, and
- * 12 bits cycleOffset, in host byte order. Cf. the Cycle Time register
- * per IEEE 1394 or Isochronous Cycle Timer register per OHCI-1394.
+ * Same as %FW_CDEV_IOC_GET_CYCLE_TIMER2, but fixed to use %CLOCK_REALTIME
+ * and only with microseconds resolution.
*
* In version 1 and 2 of the ABI, this ioctl returned unreliable (non-
* monotonic) @cycle_timer values on certain controllers.
@@ -886,10 +873,17 @@
* @clk_id: input parameter, clock from which to get the system time
* @cycle_timer: Cycle Time register contents
*
- * The %FW_CDEV_IOC_GET_CYCLE_TIMER2 works like
- * %FW_CDEV_IOC_GET_CYCLE_TIMER but lets you choose a clock like with POSIX'
- * clock_gettime function. Supported @clk_id values are POSIX' %CLOCK_REALTIME
- * and %CLOCK_MONOTONIC and Linux' %CLOCK_MONOTONIC_RAW.
+ * The %FW_CDEV_IOC_GET_CYCLE_TIMER2 ioctl reads the isochronous cycle timer
+ * and also the system clock. This allows to correlate reception time of
+ * isochronous packets with system time.
+ *
+ * @clk_id lets you choose a clock like with POSIX' clock_gettime function.
+ * Supported @clk_id values are POSIX' %CLOCK_REALTIME and %CLOCK_MONOTONIC
+ * and Linux' %CLOCK_MONOTONIC_RAW.
+ *
+ * @cycle_timer consists of 7 bits cycleSeconds, 13 bits cycleCount, and
+ * 12 bits cycleOffset, in host byte order. Cf. the Cycle Time register
+ * per IEEE 1394 or Isochronous Cycle Timer register per OHCI-1394.
*/
struct fw_cdev_get_cycle_timer2 {
__s64 tv_sec;
@@ -1011,4 +1005,6 @@
__u64 closure;
};
+#define FW_CDEV_VERSION 3 /* Meaningless legacy macro; don't use it. */
+
#endif /* _LINUX_FIREWIRE_CDEV_H */
