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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-22 14:49:48 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-22 14:49:48 -0700 |
commit | 441c196e84b11aad3123baa9320eee7abc6b5c98 (patch) | |
tree | ea51d689c9ac09cce10a5758f19d6adbd8a7a9d7 | |
parent | 951cc93a7493a81a47e20231441bc6cf17c98a37 (diff) | |
parent | 9a00c24ae7cb08dcd46edf1327a47871e8466444 (diff) | |
download | op-kernel-dev-441c196e84b11aad3123baa9320eee7abc6b5c98.zip op-kernel-dev-441c196e84b11aad3123baa9320eee7abc6b5c98.tar.gz |
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
-rw-r--r-- | Documentation/ABI/stable/firewire-cdev | 103 | ||||
-rw-r--r-- | Documentation/ABI/stable/sysfs-bus-firewire | 122 | ||||
-rw-r--r-- | drivers/firewire/core-cdev.c | 20 | ||||
-rw-r--r-- | drivers/firewire/net.c | 5 | ||||
-rw-r--r-- | drivers/firewire/ohci.c | 42 | ||||
-rw-r--r-- | include/linux/firewire-cdev.h | 78 |
6 files changed, 303 insertions, 67 deletions
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 @@ static int fw_device_op_open(struct inode *inode, struct file *file) 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 @@ static int ioctl_get_info(struct client *client, union ioctl_arg *arg) 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 @@ static int dispatch_ioctl(struct client *client, 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 @@ struct rfc2734_arp { __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 rfc2734_arp { 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 @@ static inline struct fw_ohci *fw_ohci(struct fw_card *card) #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 @@ static inline void flush_writes(const struct fw_ohci *ohci) 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 @@ static int read_phy_reg(struct fw_ohci *ohci, int addr) 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 @@ static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val) 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 @@ static void ar_context_link_page(struct ar_context *ctx, unsigned int index) 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 @@ static void ar_context_run(struct ar_context *ctx) 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 @@ static void context_stop(struct context *ctx) 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 @@ static int at_context_queue_packet(struct context *ctx, 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 irqreturn_t irq_handler(int irq, void *data) 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 @@ static int ohci_enable(struct fw_card *card, 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 @@ static void ohci_flush_queue_iso(struct fw_iso_context *base) &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_response { /** * 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 @@ union fw_cdev_event { * %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 @@ struct fw_cdev_initiate_bus_reset { * @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 @@ struct fw_cdev_initiate_bus_reset { * 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_add_descriptor { }; /** - * 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 @@ struct fw_cdev_stop_iso { * @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 @@ struct fw_cdev_get_cycle_timer { * @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 @@ struct fw_cdev_receive_phy_packets { __u64 closure; }; +#define FW_CDEV_VERSION 3 /* Meaningless legacy macro; don't use it. */ + #endif /* _LINUX_FIREWIRE_CDEV_H */ |