3 files changed, 105 insertions, 14 deletions

diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index 36526a1e76d7..867608ab3ca0 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -53,8 +53,8 @@ installmandocs: mandocs
 
 ###
 #External programs used
-KERNELDOC = scripts/kernel-doc
-DOCPROC   = scripts/basic/docproc
+KERNELDOC = $(srctree)/scripts/kernel-doc
+DOCPROC   = $(objtree)/scripts/basic/docproc
 
 XMLTOFLAGS = -m $(srctree)/Documentation/DocBook/stylesheet.xsl
 #XMLTOFLAGS += --skip-validation
diff --git a/Documentation/filesystems/fuse.txt b/Documentation/filesystems/fuse.txt
index 345392c4caeb..397a41adb4c3 100644
--- a/Documentation/filesystems/fuse.txt
+++ b/Documentation/filesystems/fuse.txt
@@ -94,8 +94,8 @@ Mount options
   filesystem is free to implement it's access policy or leave it to
   the underlying file access mechanism (e.g. in case of network
   filesystems).  This option enables permission checking, restricting
-  access based on file mode.  This is option is usually useful
-  together with the 'allow_other' mount option.
+  access based on file mode.  It is usually useful together with the
+  'allow_other' mount option.
 
 'allow_other'
 
diff --git a/Documentation/tty.txt b/Documentation/tty.txt
index dab56604745d..5f799e612e03 100644
--- a/Documentation/tty.txt
+++ b/Documentation/tty.txt
@@ -39,28 +39,37 @@ Line Discipline Methods
 
 TTY side interfaces:
 
+open()          -       Called when the line discipline is attached to
+                        the terminal. No other call into the line
+                        discipline for this tty will occur until it
+                        completes successfully. Can sleep.
+
 close()         -       This is called on a terminal when the line
                         discipline is being unplugged. At the point of
                         execution no further users will enter the
                         ldisc code for this tty. Can sleep.
 
-open()          -       Called when the line discipline is attached to
-                        the terminal. No other call into the line
-                        discipline for this tty will occur until it
-                        completes successfully. Can sleep.
+hangup()        -       Called when the tty line is hung up.
+                        The line discipline should cease I/O to the tty.
+                        No further calls into the ldisc code will occur.
+                        Can sleep.
 
 write()         -       A process is writing data through the line
                         discipline.  Multiple write calls are serialized
                         by the tty layer for the ldisc.  May sleep. 
 
-flush_buffer()  -       May be called at any point between open and close.
+flush_buffer()  -       (optional) May be called at any point between
+                        open and close, and instructs the line discipline
+                        to empty its input buffer.
 
-chars_in_buffer() -     Report the number of bytes in the buffer.
+chars_in_buffer() -     (optional) Report the number of bytes in the input
+                        buffer.
 
-set_termios()   -       Called on termios structure changes. The caller
-                        passes the old termios data and the current data
-                        is in the tty. Called under the termios semaphore so
-                        allowed to sleep. Serialized against itself only.
+set_termios()   -       (optional) Called on termios structure changes.
+                        The caller passes the old termios data and the
+                        current data is in the tty. Called under the
+                        termios semaphore so allowed to sleep. Serialized
+                        against itself only.
 
 read()          -       Move data from the line discipline to the user.
                         Multiple read calls may occur in parallel and the
@@ -92,6 +101,88 @@ write_wakeup()	-	May be called at any point between open and close.
                         this function. In such a situation defer it.
 
 
+Driver Access
+
+Line discipline methods can call the following methods of the underlying
+hardware driver through the function pointers within the tty->driver
+structure:
+
+write()                 Write a block of characters to the tty device.
+                        Returns the number of characters accepted.
+
+put_char()              Queues a character for writing to the tty device.
+                        If there is no room in the queue, the character is
+                        ignored.
+
+flush_chars()           (Optional) If defined, must be called after
+                        queueing characters with put_char() in order to
+                        start transmission.
+
+write_room()            Returns the numbers of characters the tty driver
+                        will accept for queueing to be written.
+
+ioctl()                 Invoke device specific ioctl.
+                        Expects data pointers to refer to userspace.
+                        Returns ENOIOCTLCMD for unrecognized ioctl numbers.
+
+set_termios()           Notify the tty driver that the device's termios
+                        settings have changed. New settings are in
+                        tty->termios. Previous settings should be passed in
+                        the "old" argument.
+
+throttle()              Notify the tty driver that input buffers for the
+                        line discipline are close to full, and it should
+                        somehow signal that no more characters should be
+                        sent to the tty.
+
+unthrottle()            Notify the tty driver that characters can now be
+                        sent to the tty without fear of overrunning the
+                        input buffers of the line disciplines.
+
+stop()                  Ask the tty driver to stop outputting characters
+                        to the tty device.
+
+start()                 Ask the tty driver to resume sending characters
+                        to the tty device.
+
+hangup()                Ask the tty driver to hang up the tty device.
+
+break_ctl()             (Optional) Ask the tty driver to turn on or off
+                        BREAK status on the RS-232 port.  If state is -1,
+                        then the BREAK status should be turned on; if
+                        state is 0, then BREAK should be turned off.
+                        If this routine is not implemented, use ioctls
+                        TIOCSBRK / TIOCCBRK instead.
+
+wait_until_sent()       Waits until the device has written out all of the
+                        characters in its transmitter FIFO.
+
+send_xchar()            Send a high-priority XON/XOFF character to the device.
+
+
+Flags
+
+Line discipline methods have access to tty->flags field containing the
+following interesting flags:
+
+TTY_THROTTLED           Driver input is throttled. The ldisc should call
+                        tty->driver->unthrottle() in order to resume
+                        reception when it is ready to process more data.
+
+TTY_DO_WRITE_WAKEUP     If set, causes the driver to call the ldisc's
+                        write_wakeup() method in order to resume
+                        transmission when it can accept more data
+                        to transmit.
+
+TTY_IO_ERROR            If set, causes all subsequent userspace read/write
+                        calls on the tty to fail, returning -EIO.
+
+TTY_OTHER_CLOSED        Device is a pty and the other side has closed.
+
+TTY_NO_WRITE_SPLIT      Prevent driver from splitting up writes into
+                        smaller chunks.
+
+
 Locking
 
 Callers to the line discipline functions from the tty layer are required to