Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6baddba4 authored by Henrique de Moraes Holschuh's avatar Henrique de Moraes Holschuh Committed by Richard Purdie
Browse files

backlight/thinkpad-acpi: issue backlight class events 



Take advantage of the new events capabilities of the backlight class to
notify userspace of backlight changes.

Signed-off-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: default avatarRichard Purdie <rpurdie@linux.intel.com>
parent 8bea8672

Documentation/laptops/thinkpad-acpi.txt

+12 −39
Original line number Diff line number Diff line
@@ -460,6 +460,8 @@ event code Key Notes 
				For Lenovo ThinkPads with a new

				BIOS, it has to be handled either

				by the ACPI OSI, or by userspace.

				The driver does the right thing,

				never mess with this.

0x1011	0x10	FN+END		Brightness down.  See brightness

				up for details.
@@ -582,46 +584,15 @@ with hotkey_report_mode. 


Brightness hotkey notes:



These are the current sane choices for brightness key mapping in

thinkpad-acpi:

Don't mess with the brightness hotkeys in a Thinkpad.  If you want

notifications for OSD, use the sysfs backlight class event support.



For IBM and Lenovo models *without* ACPI backlight control (the ones on

which thinkpad-acpi will autoload its backlight interface by default,

and on which ACPI video does not export a backlight interface):



1. Don't enable or map the brightness hotkeys in thinkpad-acpi, as

   these older firmware versions unfortunately won't respect the hotkey

   mask for brightness keys anyway, and always reacts to them.  This

   usually work fine, unless X.org drivers are doing something to block

   the BIOS.  In that case, use (3) below.  This is the default mode of

   operation.



2. Enable the hotkeys, but map them to something else that is NOT

   KEY_BRIGHTNESS_UP/DOWN or any other keycode that would cause

   userspace to try to change the backlight level, and use that as an

   on-screen-display hint.



3. IF AND ONLY IF X.org drivers find a way to block the firmware from

   automatically changing the brightness, enable the hotkeys and map

   them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN, and feed that to

   something that calls xbacklight.  thinkpad-acpi will not be able to

   change brightness in that case either, so you should disable its

   backlight interface.



For Lenovo models *with* ACPI backlight control:



1. Load up ACPI video and use that.  ACPI video will report ACPI

   events for brightness change keys.  Do not mess with thinkpad-acpi

   defaults in this case.  thinkpad-acpi should not have anything to do

   with backlight events in a scenario where ACPI video is loaded:

   brightness hotkeys must be disabled, and the backlight interface is

   to be kept disabled as well.  This is the default mode of operation.



2. Do *NOT* load up ACPI video, enable the hotkeys in thinkpad-acpi,

   and map them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN.  Process

   these keys on userspace somehow (e.g. by calling xbacklight).

   The driver will do this automatically if it detects that ACPI video

   has been disabled.

The driver will issue KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN events

automatically for the cases were userspace has to do something to

implement brightness changes.  When you override these events, you will

either fail to handle properly the ThinkPads that require explicit

action to change backlight brightness, or the ThinkPads that require

that no action be taken to work properly.





Bluetooth
@@ -1465,3 +1436,5 @@ Sysfs interface changelog: 
		and it is always able to disable hot keys.  Very old

		thinkpads are properly supported.  hotkey_bios_mask

		is deprecated and marked for removal.



0x020600:	Marker for backlight change event support.

drivers/platform/x86/thinkpad_acpi.c

+23 −1
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ 
 */



#define TPACPI_VERSION "0.23"

#define TPACPI_SYSFS_VERSION 0x020500

#define TPACPI_SYSFS_VERSION 0x020600



/*

 *  Changelog:
@@ -6092,6 +6092,12 @@ static int brightness_get(struct backlight_device *bd) 
	return status & TP_EC_BACKLIGHT_LVLMSK;

}



static void tpacpi_brightness_notify_change(void)

{

	backlight_force_update(ibm_backlight_device,

			       BACKLIGHT_UPDATE_HOTKEY);

}



static struct backlight_ops ibm_backlight_data = {

	.get_brightness = brightness_get,

	.update_status  = brightness_update_status,
@@ -6246,6 +6252,12 @@ static int __init brightness_init(struct ibm_init_struct *iibm) 
	ibm_backlight_device->props.brightness = b & TP_EC_BACKLIGHT_LVLMSK;

	backlight_update_status(ibm_backlight_device);



	vdbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_BRGHT,

			"brightness: registering brightness hotkeys "

			"as change notification\n");

	tpacpi_hotkey_driver_mask_set(hotkey_driver_mask

				| TP_ACPI_HKEY_BRGHTUP_MASK

				| TP_ACPI_HKEY_BRGHTDWN_MASK);;

	return 0;

}
@@ -6322,6 +6334,9 @@ static int brightness_write(char *buf) 
	 * Doing it this way makes the syscall restartable in case of EINTR

	 */

	rc = brightness_set(level);

	if (!rc && ibm_backlight_device)

		backlight_force_update(ibm_backlight_device,

					BACKLIGHT_UPDATE_SYSFS);

	return (rc == -EINTR)? -ERESTARTSYS : rc;

}
@@ -7721,6 +7736,13 @@ static struct ibm_struct fan_driver_data = { 
 */

static void tpacpi_driver_event(const unsigned int hkey_event)

{

	if (ibm_backlight_device) {

		switch (hkey_event) {

		case TP_HKEY_EV_BRGHT_UP:

		case TP_HKEY_EV_BRGHT_DOWN:

			tpacpi_brightness_notify_change();

		}

	}

}