PowerBook button device control back to user space

Hi Ben,

The following patch removes a unlucky shortcut from keyboard device to the PMU backlight device from the kernel and gives control back to user space.

The Apple PowerBooks have a special button device to control special functions like display brightness, speaker volume, etc. The Keys for volume control generate keycodes, which were sent to user space. The keys for controlling the display brightness were directly handled by the kernel. This is not consequent and additionally an unlucky cross reference between different and independent parts of the kernel.

Due to the existance of multiply sound systems, it would be very annoying to put all the volume control features into the kernel like the brightness control and at the end the user still hasn't any visual feedback during his volumem/brightness adjustments.

So I suggest to remove the direct handling of the display brightness from the kernel. The correspondent keys should also send key codes to user space and allow a user space programm to get into control. It could react more flexible to users needs and disburden the kernel from secondary jobs.

I could provide a first release of this user space program to control all PowerBook special keys including visual feedback. (under GPL)

My patch only concerns the new adbhid driver. In the old macintosh keyboard driver the button device keys can't be assigned to scancodes, because there are none free. So in this driver I keep the direct control of the backlight device because it is better than nothing.

The patch based on kernel 2.4.16-benh but work straight forward with 2.4.18-pre7-benh0.

Kind regards
Matthias Grimm

diff -urN -X dontdiff kernel-2.4.16-benh/drivers/macintosh/adbhid.c kernel-2.4.16-mgr/drivers/macintosh/adbhid.c
@@ -42,9 +42,6 @@
 #include <linux/adb.h>
 #include <linux/cuda.h>
 #include <linux/pmu.h>
-#ifdef CONFIG_PMAC_BACKLIGHT
-#include <asm/backlight.h>
-#endif
 
 MODULE_AUTHOR("Franz Sirl <[email protected]>");
 

@@ -274,9 +271,7 @@
 	case 0x1f: /* Powerbook button device */
 	  {
 	  	int down = (data[1] == (data[1] & 0xf));
-#ifdef CONFIG_PMAC_BACKLIGHT
-

	int backlight = get_backlight_level();

-#endif
+
/*
* XXX: Where is the contrast control for the passive?
* -- Cort
@@ -284,44 +279,28 @@

switch (data[1] & 0x0f) {
case 0x8: /* mute */
-

		input_report_key(&adbhid[id]->input, KEY_MUTE,
-
			data[1] == (data[1] & 0xf));
+
		input_report_key(&adbhid[id]->input, KEY_MUTE, down);

	break;

case 0x7: /* volume decrease */
-

		input_report_key(&adbhid[id]->input, KEY_VOLUMEDOWN,
-
			data[1] == (data[1] & 0xf));
+
		input_report_key(&adbhid[id]->input, KEY_VOLUMEDOWN, down);

	break;

case 0x6: /* volume increase */
-

		input_report_key(&adbhid[id]->input, KEY_VOLUMEUP,
-
			data[1] == (data[1] & 0xf));
+
		input_report_key(&adbhid[id]->input, KEY_VOLUMEUP, down);

break;

case 0xb: /* eject */
-

		input_report_key(&adbhid[id]->input, KEY_EJECTCD,
-
			data[1] == (data[1] & 0xf));
+
		input_report_key(&adbhid[id]->input, KEY_EJECTCD, down);

	break;

-#ifdef CONFIG_PMAC_BACKLIGHT
case 0xa: /* brightness decrease */
-

		if (!down || backlight < 0)
-
			break;
-
		if (backlight > BACKLIGHT_OFF)
-
			set_backlight_level(backlight-1);
-
		else
-
			set_backlight_level(BACKLIGHT_OFF);
+
		input_report_key(&adbhid[id]->input, KEY_BRIGHTNESSDOWN, down);

	break;

case 0x9: /* brightness increase */
-

		if (!down || backlight < 0)
-
			break;
-
		if (backlight < BACKLIGHT_MAX)
-
			set_backlight_level(backlight+1);
-
		else
-
			set_backlight_level(BACKLIGHT_MAX);
+
		input_report_key(&adbhid[id]->input, KEY_BRIGHTNESSUP, down);

	break;

-#endif /* CONFIG_PMAC_BACKLIGHT */
}
}
break;
@@ -521,6 +500,8 @@

	set_bit(KEY_MUTE, adbhid[id]->input.keybit);

	set_bit(KEY_VOLUMEUP, adbhid[id]->input.keybit);

	set_bit(KEY_VOLUMEDOWN, adbhid[id]->input.keybit);
+
		set_bit(KEY_BRIGHTNESSUP, adbhid[id]->input.keybit);
+
		set_bit(KEY_BRIGHTNESSDOWN, adbhid[id]->input.keybit);

	set_bit(KEY_EJECTCD, adbhid[id]->input.keybit);

	break;

}

diff -urN -X dontdiff kernel-2.4.16-benh/drivers/macintosh/mac_hid.c kernel-2.4.16-mgr/drivers/macintosh/mac_hid.c
@@ -204,7 +204,7 @@
 	0, 0, 0, 0, 0, KEY_VOLUMEDOWN, KEY_MUTE, 0,		/* 0x20-0x27 */
 	0, 0, 0, 0, 0, 0, 0, 0,					/* 0x28-0x2f */
 	0, 0, 0, 0, 0, KEY_KPSLASH, 0, KEY_SYSRQ,		/* 0x30-0x37 */
-

KEY_RIGHTALT, 0, 0, KEY_EJECTCD, 0, 0, 0, 0, /* 0x38-0x3f */
+
KEY_RIGHTALT, KEY_BRIGHTNESSUP, KEY_BRIGHTNESSDOWN, KEY_EJECTCD, 0, 0, 0, 0, /* 0x38-0x3f */
0, 0, 0, 0, 0, 0, 0, KEY_HOME, /* 0x40-0x47 */
KEY_UP, KEY_PAGEUP, 0, KEY_LEFT, 0, KEY_RIGHT, 0, KEY_END, /* 0x48-0x4f */ KEY_DOWN, KEY_PAGEDOWN, KEY_INSERT, KEY_DELETE, 0, 0, 0, 0, /* 0x50-0x57 */

diff -urN -X dontdiff kernel-2.4.16-benh/include/linux/input.h kernel-2.4.16-mgr/include/linux/input.h
@@ -305,6 +305,9 @@
 #define KEY_SUSPEND		205
 #define KEY_CLOSE		206
 
+#define KEY_BRIGHTNESSUP	210
+#define KEY_BRIGHTNESSDOWN	211
+
 #define KEY_UNKNOWN		220
 
 #define BTN_MISC		0x100

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Hi Matthias. The presence of direct backlight handling in the kernel is an artifact of old days ;) Actually, other controls (sound, CD eject) of new powerbooks are sent to the even device and a userland daemon already exist (ikeyd) for taking care of those events.

The problem currently is that not all powerbook models send those as ADB keycodes, some are obtained via special PMU events directly in via-pmu. So before backlight handling is moved to an ikeyd-like daemon, we should first fix the kernel to properly send those events on all models. I don't suggest changing this in the 2.4 timeframe though.

Ben.

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/