docs: console.txt: convert docs to ReST and rename to *.rst
Convert this small file to ReST in preparation for adding it to the driver-api book. While this is not part of the driver-api book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
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				|  | @ -1,3 +1,6 @@ | |||
| :orphan: | ||||
| 
 | ||||
| =============== | ||||
| Console Drivers | ||||
| =============== | ||||
| 
 | ||||
|  | @ -17,25 +20,26 @@ 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 | ||||
| released by the console, the system driver will take over. | ||||
| 
 | ||||
| Modular drivers, from the programmer's point of view, have to call: | ||||
| Modular drivers, from the programmer's point of view, have to call:: | ||||
| 
 | ||||
| 	 do_take_over_console() - load and bind driver to console layer | ||||
| 	 give_up_console() - unload driver; it will only work if driver | ||||
| 			     is fully unbound | ||||
| 
 | ||||
| In newer kernels, the following are also available: | ||||
| In newer kernels, the following are also available:: | ||||
| 
 | ||||
| 	 do_register_con_driver() | ||||
| 	 do_unregister_con_driver() | ||||
| 
 | ||||
| If sysfs is enabled, the contents of /sys/class/vtconsole can be | ||||
| examined. This shows the console backends currently registered by the | ||||
| system which are named vtcon<n> where <n> is an integer from 0 to 15. Thus: | ||||
| system which are named vtcon<n> where <n> is an integer from 0 to 15. | ||||
| Thus:: | ||||
| 
 | ||||
|        ls /sys/class/vtconsole | ||||
|        .  ..  vtcon0  vtcon1 | ||||
| 
 | ||||
| Each directory in /sys/class/vtconsole has 3 files: | ||||
| Each directory in /sys/class/vtconsole has 3 files:: | ||||
| 
 | ||||
|      ls /sys/class/vtconsole/vtcon0 | ||||
|      .  ..  bind  name  uevent | ||||
|  | @ -46,27 +50,29 @@ What do these files signify? | |||
|         read, or acts to bind or unbind the driver to the virtual consoles | ||||
|         when written to. The possible values are: | ||||
| 
 | ||||
| 	0 - means the driver is not bound and if echo'ed, commands the driver | ||||
| 	0 | ||||
| 	  - means the driver is not bound and if echo'ed, commands the driver | ||||
| 	    to unbind | ||||
| 
 | ||||
|         1 - means the driver is bound and if echo'ed, commands the driver to | ||||
|         1 | ||||
| 	  - means the driver is bound and if echo'ed, commands the driver to | ||||
| 	    bind | ||||
| 
 | ||||
|      2. name - read-only file. Shows the name of the driver in this format: | ||||
|      2. name - read-only file. Shows the name of the driver in this format:: | ||||
| 
 | ||||
| 	cat /sys/class/vtconsole/vtcon0/name | ||||
| 	(S) VGA+ | ||||
| 	  cat /sys/class/vtconsole/vtcon0/name | ||||
| 	  (S) VGA+ | ||||
| 
 | ||||
| 	    '(S)' stands for a (S)ystem driver, i.e., it cannot be directly | ||||
| 	    commanded to bind or unbind | ||||
| 	      '(S)' stands for a (S)ystem driver, i.e., it cannot be directly | ||||
| 	      commanded to bind or unbind | ||||
| 
 | ||||
| 	    'VGA+' is the name of the driver | ||||
| 	      'VGA+' is the name of the driver | ||||
| 
 | ||||
| 	cat /sys/class/vtconsole/vtcon1/name | ||||
| 	(M) frame buffer device | ||||
| 	  cat /sys/class/vtconsole/vtcon1/name | ||||
| 	  (M) frame buffer device | ||||
| 
 | ||||
| 	    In this case, '(M)' stands for a (M)odular driver, one that can be | ||||
| 	    directly commanded to bind or unbind. | ||||
| 	      In this case, '(M)' stands for a (M)odular driver, one that can be | ||||
| 	      directly commanded to bind or unbind. | ||||
| 
 | ||||
|      3. uevent - ignore this file | ||||
| 
 | ||||
|  | @ -75,14 +81,17 @@ driver takes over the consoles vacated by the driver. Binding, on the other | |||
| hand, will bind the driver to the consoles that are currently occupied by a | ||||
| system driver. | ||||
| 
 | ||||
| NOTE1: Binding and unbinding must be selected in Kconfig. It's under: | ||||
| NOTE1: | ||||
|   Binding and unbinding must be selected in Kconfig. It's under:: | ||||
| 
 | ||||
| Device Drivers -> Character devices -> Support for binding and unbinding | ||||
| console drivers | ||||
|     Device Drivers -> | ||||
| 	Character devices -> | ||||
| 		Support for binding and unbinding console drivers | ||||
| 
 | ||||
| NOTE2: If any of the virtual consoles are in KD_GRAPHICS mode, then binding or | ||||
| unbinding will not succeed. An example of an application that sets the console | ||||
| to KD_GRAPHICS is X. | ||||
| NOTE2: | ||||
|   If any of the virtual consoles are in KD_GRAPHICS mode, then binding or | ||||
|   unbinding will not succeed. An example of an application that sets the | ||||
|   console to KD_GRAPHICS is X. | ||||
| 
 | ||||
| How useful is this feature? This is very useful for console driver | ||||
| developers. By unbinding the driver from the console layer, one can unload the | ||||
|  | @ -92,10 +101,10 @@ framebuffer console to VGA console and vice versa, this feature also makes | |||
| this possible. (NOTE NOTE NOTE: Please read fbcon.txt under Documentation/fb | ||||
| for more details.) | ||||
| 
 | ||||
| Notes for developers: | ||||
| ===================== | ||||
| Notes for developers | ||||
| ==================== | ||||
| 
 | ||||
| do_take_over_console() is now broken up into: | ||||
| do_take_over_console() is now broken up into:: | ||||
| 
 | ||||
|      do_register_con_driver() | ||||
|      do_bind_con_driver() - private function | ||||
|  | @ -104,7 +113,7 @@ 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 | ||||
| driver is bound or not. | ||||
| 
 | ||||
| Guidelines for console driver writers: | ||||
| Guidelines for console driver writers | ||||
| ===================================== | ||||
| 
 | ||||
| In order for binding to and unbinding from the console to properly work, | ||||
|  | @ -140,6 +149,4 @@ The current crop of console drivers should still work correctly, but binding | |||
| and unbinding them may cause problems. With minimal fixes, these drivers can | ||||
| be made to work correctly. | ||||
| 
 | ||||
| ========================== | ||||
| Antonino Daplas <adaplas@pol.net> | ||||
| 
 | ||||
|  | @ -187,7 +187,7 @@ the hardware. Thus, in a VGA console:: | |||
| Assuming the VGA driver can be unloaded, one must first unbind the VGA driver | ||||
| from the console layer before unloading the driver.  The VGA driver cannot be | ||||
| unloaded if it is still bound to the console layer. (See | ||||
| Documentation/console/console.txt for more information). | ||||
| Documentation/console/console.rst for more information). | ||||
| 
 | ||||
| This is more complicated in the case of the framebuffer console (fbcon), | ||||
| because fbcon is an intermediate layer between the console and the drivers:: | ||||
|  | @ -204,7 +204,7 @@ fbcon. Thus, there is no need to explicitly unbind the fbdev drivers from | |||
| fbcon. | ||||
| 
 | ||||
| So, how do we unbind fbcon from the console? Part of the answer is in | ||||
| Documentation/console/console.txt. To summarize: | ||||
| Documentation/console/console.rst. To summarize: | ||||
| 
 | ||||
| Echo a value to the bind file that represents the framebuffer console | ||||
| driver. So assuming vtcon1 represents fbcon, then:: | ||||
|  |  | |||
|  | @ -93,7 +93,7 @@ config VT_HW_CONSOLE_BINDING | |||
|          select the console driver that will serve as the backend for the | ||||
|          virtual terminals. | ||||
| 
 | ||||
| 	 See <file:Documentation/console/console.txt> for more | ||||
| 	 See <file:Documentation/console/console.rst> for more | ||||
| 	 information. For framebuffer console users, please refer to | ||||
| 	 <file:Documentation/fb/fbcon.rst>. | ||||
| 
 | ||||
|  |  | |||
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