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| author | Kevin Cernekee <cernekee@gmail.com> | 2012-12-26 20:43:42 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-15 21:57:44 -0800 |
| commit | e759d7c53b39a43fc908425bf9985b8b7d930550 (patch) | |
| tree | 1dda0be7eed24d1ac06d43e8dbdd63a924280608 /Documentation/serial | |
| parent | ef4f527c48c8fcbb5e35dafaef4f9097f5e9d901 (diff) | |
| download | lwn-e759d7c53b39a43fc908425bf9985b8b7d930550.tar.gz lwn-e759d7c53b39a43fc908425bf9985b8b7d930550.zip | |
tty: Update serial core API documentation
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/serial')
| -rw-r--r-- | Documentation/serial/driver | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/serial/driver b/Documentation/serial/driver index a6ef8dc436f1..067c47d46917 100644 --- a/Documentation/serial/driver +++ b/Documentation/serial/driver @@ -133,6 +133,16 @@ hardware. Interrupts: locally disabled. This call must not sleep + send_xchar(port,ch) + Transmit a high priority character, even if the port is stopped. + This is used to implement XON/XOFF flow control and tcflow(). If + the serial driver does not implement this function, the tty core + will append the character to the circular buffer and then call + start_tx() / stop_tx() to flush the data out. + + Locking: none. + Interrupts: caller dependent. + stop_rx(port) Stop receiving characters; the port is in the process of being closed. @@ -254,6 +264,10 @@ hardware. Locking: none. Interrupts: caller dependent. + set_wake(port,state) + Enable/disable power management wakeup on serial activity. Not + currently implemented. + type(port) Return a pointer to a string constant describing the specified port, or return NULL, in which case the string 'unknown' is @@ -306,6 +320,31 @@ hardware. Locking: none. Interrupts: caller dependent. + poll_init(port) + Called by kgdb to perform the minimal hardware initialization needed + to support poll_put_char() and poll_get_char(). Unlike ->startup() + this should not request interrupts. + + Locking: tty_mutex and tty_port->mutex taken. + Interrupts: n/a. + + poll_put_char(port,ch) + Called by kgdb to write a single character directly to the serial + port. It can and should block until there is space in the TX FIFO. + + Locking: none. + Interrupts: caller dependent. + This call must not sleep + + poll_get_char(port) + Called by kgdb to read a single character directly from the serial + port. If data is available, it should be returned; otherwise + the function should return NO_POLL_CHAR immediately. + + Locking: none. + Interrupts: caller dependent. + This call must not sleep + Other functions --------------- |