1 files changed, 37 insertions, 41 deletions

diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h
index 4ff09889c5c0..357dbfc2829e 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 */