TTY:console: update document console.txt

Update Documentatin/console/console.txt to
reflect the following changes:

take_over_console|register_con_driver|unregister_con_driver|bind_con_driver
had gone, they had been replace by the new caller hold console lock version,
do_take_over_console|do_register_con_driver|do_unregister_con_driver|do_bind_con_driver.

This patch also fix a place include wrong description about give_up_console.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Wang YanQing 2013-05-21 23:29:11 +08:00 коммит произвёл Greg Kroah-Hartman
Родитель 155957f56c
Коммит 6b5f146535
1 изменённых файлов: 14 добавлений и 14 удалений

Просмотреть файл

@ -12,20 +12,20 @@ The second type has to be explicitly loaded and unloaded. This will be called
any time with each driver sharing the console with other drivers including any time with each driver sharing the console with other drivers including
the system driver. However, modular drivers cannot take over the console the system driver. However, modular drivers cannot take over the console
that is currently occupied by another modular driver. (Exception: Drivers that that is currently occupied by another modular driver. (Exception: Drivers that
call take_over_console() will succeed in the takeover regardless of the type call do_take_over_console() will succeed in the takeover regardless of the type
of driver occupying the consoles.) They can only take over the console that is of driver occupying the consoles.) They can only take over the console that is
occupied by the system driver. In the same token, if the modular driver is occupied by the system driver. In the same token, if the modular driver is
released by the console, the system driver will take over. released by the console, the system driver will take over.
Modular drivers, from the programmer's point of view, has to call: Modular drivers, from the programmer's point of view, has to call:
take_over_console() - load and bind driver to console layer do_take_over_console() - load and bind driver to console layer
give_up_console() - unbind and unload driver give_up_console() - unload driver, it will only work if driver is fully unbond
In newer kernels, the following are also available: In newer kernels, the following are also available:
register_con_driver() do_register_con_driver()
unregister_con_driver() do_unregister_con_driver()
If sysfs is enabled, the contents of /sys/class/vtconsole can be If sysfs is enabled, the contents of /sys/class/vtconsole can be
examined. This shows the console backends currently registered by the examined. This shows the console backends currently registered by the
@ -94,12 +94,12 @@ for more details).
Notes for developers: Notes for developers:
===================== =====================
take_over_console() is now broken up into: do_take_over_console() is now broken up into:
register_con_driver() do_register_con_driver()
bind_con_driver() - private function do_bind_con_driver() - private function
give_up_console() is a wrapper to unregister_con_driver(), and a driver must give_up_console() is a wrapper to do_unregister_con_driver(), and a driver must
be fully unbound for this call to succeed. con_is_bound() will check if the be fully unbound for this call to succeed. con_is_bound() will check if the
driver is bound or not. driver is bound or not.
@ -109,10 +109,10 @@ Guidelines for console driver writers:
In order for binding to and unbinding from the console to properly work, In order for binding to and unbinding from the console to properly work,
console drivers must follow these guidelines: console drivers must follow these guidelines:
1. All drivers, except system drivers, must call either register_con_driver() 1. All drivers, except system drivers, must call either do_register_con_driver()
or take_over_console(). register_con_driver() will just add the driver to or do_take_over_console(). do_register_con_driver() will just add the driver to
the console's internal list. It won't take over the the console's internal list. It won't take over the
console. take_over_console(), as it name implies, will also take over (or console. do_take_over_console(), as it name implies, will also take over (or
bind to) the console. bind to) the console.
2. All resources allocated during con->con_init() must be released in 2. All resources allocated during con->con_init() must be released in
@ -128,10 +128,10 @@ console drivers must follow these guidelines:
rebind the driver to the console arrives. rebind the driver to the console arrives.
4. Upon exit of the driver, ensure that the driver is totally unbound. If the 4. Upon exit of the driver, ensure that the driver is totally unbound. If the
condition is satisfied, then the driver must call unregister_con_driver() condition is satisfied, then the driver must call do_unregister_con_driver()
or give_up_console(). or give_up_console().
5. unregister_con_driver() can also be called on conditions which make it 5. do_unregister_con_driver() can also be called on conditions which make it
impossible for the driver to service console requests. This can happen impossible for the driver to service console requests. This can happen
with the framebuffer console that suddenly lost all of its drivers. with the framebuffer console that suddenly lost all of its drivers.