tty: combine tty_operations triple docs into kernel-doc

In Documentation/driver-api/serial/tty.rst, there are triplicated texts
about some struct tty_operations' hooks. Combine them into existing
kernel-doc comments of struct tty_operations and drop them from the
Documentation/.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211126081611.11001-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 132 deletions

diff --git a/Documentation/driver-api/serial/tty.rst b/Documentation/driver-api/serial/tty.rst
index 4b709f392713..f7ef10c6f458 100644
--- a/Documentation/driver-api/serial/tty.rst
+++ b/Documentation/driver-api/serial/tty.rst
@@ -132,74 +132,8 @@ dcd_change()		Report to the tty line the current DCD pin status
 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. The
-			character buffer passed to this method is already
-			in kernel space.
-
-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.
-
-			The API is defined such that the driver should return
-			the actual modes selected. This means that the
-			driver function is responsible for modifying any
-			bits in the request it cannot fulfill to indicate
-			the actual modes being used. A device with no
-			hardware capability for change (e.g. a USB dongle or
-			virtual port) can provide NULL for this method.
-
-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.
-======================= =======================================================
-
+Line discipline methods can call the methods of the underlying hardware driver.
+These are documented as a part of struct tty_operations.
 
 Flags
 ^^^^^
@@ -262,67 +196,3 @@ A caution: The ldisc->open(), ldisc->close() and driver->set_ldisc
 functions are called with the ldisc unavailable. Thus tty_ldisc_ref will
 fail in this situation if used within these functions. Ldisc and driver
 code calling its own functions must be careful in this case.
-
-
-Driver Interface
-----------------
-
-======================= =======================================================
-open()			Called when a device is opened. May sleep
-
-close()			Called when a device is closed. At the point of
-			return from this call the driver must make no
-			further ldisc calls of any kind. May sleep
-
-write()			Called to write bytes to the device. May not
-			sleep. May occur in parallel in special cases.
-			Because this includes panic paths drivers generally
-			shouldn't try and do clever locking here.
-
-put_char()		Stuff a single character onto the queue. The
-			driver is guaranteed following up calls to
-			flush_chars.
-
-flush_chars()		Ask the kernel to write put_char queue
-
-write_room()		Return the number of characters that can be stuffed
-			into the port buffers without overflow (or less).
-			The ldisc is responsible for being intelligent
-			about multi-threading of write_room/write calls
-
-ioctl()			Called when an ioctl may be for the driver
-
-set_termios()		Called on termios change, serialized against
-			itself by a semaphore. May sleep.
-
-set_ldisc()		Notifier for discipline change. At the point this
-			is done the discipline is not yet usable. Can now
-			sleep (I think)
-
-throttle()		Called by the ldisc to ask the driver to do flow
-			control.  Serialization including with unthrottle
-			is the job of the ldisc layer.
-
-unthrottle()		Called by the ldisc to ask the driver to stop flow
-			control.
-
-stop()			Ldisc notifier to the driver to stop output. As with
-			throttle the serializations with start() are down
-			to the ldisc layer.
-
-start()			Ldisc notifier to the driver to start output.
-
-hangup()		Ask the tty driver to cause a hangup initiated
-			from the host side. [Can sleep ??]
-
-break_ctl()		Send RS232 break. Can sleep. Can get called in
-			parallel, driver must serialize (for now), and
-			with write calls.
-
-wait_until_sent()	Wait for characters to exit the hardware queue
-			of the driver. Can sleep
-
-send_xchar()	  	Send XON/XOFF and if possible jump the queue with
-			it in order to get fast flow control responses.
-			Cannot sleep ??
-======================= =======================================================