Commit 67ab7f59 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[SERIAL] Update serial driver documentation

Improve serial driver documentation:
- Remove CVS id.
- Update pointer to reference driver documentation.
- Add comments about new uart_write_console function.
- Add TIOCM_LOOP modem control bit description.
- Add commentry about enable_ms method being called multiple times.
- Add commentry about startup/shutdown method calling.
- Mention that dereferencing port->info after shutdown is invalid.
Signed-off-by: default avatarRussell King <>
parent 2c536200
......@@ -3,14 +3,11 @@
$Id: driver,v 1.10 2002/07/22 15:27:30 rmk Exp $
This document is meant as a brief overview of some aspects of the new serial
driver. It is not complete, any questions you have should be directed to
The reference implementation is contained within serial_amba.c.
The reference implementation is contained within amba_pl011.c.
......@@ -31,6 +28,11 @@ The serial core provides a few helper functions. This includes identifing
the correct port structure (via uart_get_console) and decoding command line
arguments (uart_parse_options).
There is also a helper function (uart_write_console) which performs a
character by character write, translating newlines to CRLF sequences.
Driver writers are recommended to use this function rather than implementing
their own version.
......@@ -86,6 +88,7 @@ hardware.
- TIOCM_DTR DTR signal.
- TIOCM_OUT1 OUT1 signal.
- TIOCM_OUT2 OUT2 signal.
- TIOCM_LOOP Set the port into loopback mode.
If the appropriate bit is set, the signal should be driven
active. If the bit is clear, the signal should be driven
......@@ -141,6 +144,10 @@ hardware.
Enable the modem status interrupts.
This method may be called multiple times. Modem status
interrupts should be disabled when the shutdown method is
Locking: port->lock taken.
Interrupts: locally disabled.
This call must not sleep
......@@ -160,6 +167,8 @@ hardware.
state. Enable the port for reception. It should not activate
RTS nor DTR; this will be done via a separate call to set_mctrl.
This method will only be called when the port is initially opened.
Locking: port_sem taken.
Interrupts: globally disabled.
......@@ -169,6 +178,11 @@ hardware.
RTS nor DTR; this will have already been done via a separate
call to set_mctrl.
Drivers must not access port->info once this call has completed.
This method will only be called when there are no more users of
this port.
Locking: port_sem taken.
Interrupts: caller dependent.
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