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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 <rmk+kernel@arm.linux.org.uk>
parent 2c536200

Documentation/serial/driver

+18 −4
Original line number Diff line number Diff line
@@ -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

<rmk@arm.linux.org.uk>



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.





Locking

-------
@@ -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

	inactive.
@@ -141,6 +144,10 @@ hardware. 
  enable_ms(port)

	Enable the modem status interrupts.



	This method may be called multiple times.  Modem status

	interrupts should be disabled when the shutdown method is

	called.



	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.