Re: [PATCH] Disable Trackpad while typing

Torsten Foertsch (torsten.foertsch@gmx.net)
Sun, 22 Jun 2003 19:05:09 +0200


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Here is now an improved version of the patch. It's against 2.4.21.

The following has changed from the original patch by Hans-Georg Thien
<1682-600@onlinehome.de>:

- - mouse events are dropped in 12 byte chunks to better fit the PS/2 mouse
protocol. That avoids spurious mouse events when the mouse is moving while
the delay timer is being reached.

- - to disable the feature after pressing or releasing some particular keys
(CTRL, SHIFT, ...) now keycodes instead of scancodes are used. "showkey -k"
shows the correct values. The bit 0x100 is used to distinguish press and
release events. 0 means press, 1 release. So,

escape 97
escape 29

mean disable "Disable Trackpad while typing" after pressing right and left
CTRL (useful for xterm users). While

escape 353 # 97+256
escape 258 # 29+256

mean disable "Disable Trackpad while typing" after releasing right and left
CTRL.

- - escaped keys are reported in /proc/tty/ps2-trackpad as decimal as "showkey
- -k" also display them as decimal. On input sscanf( "%i" ) is expected.

- - Documentation has been moved from Documentation/Configure.help to a separate
file Documentation/ps2-trackpad.txt.

History:
http://marc.theaimsgroup.com/?l=linux-kernel&w=2&r=1&s=DISABLE_TRACKPAD_WHILE_TYPING&q=b

Torsten

diff -Naur -X dontdiff linux-2.4.21-orig/Documentation/Configure.help
linux-2.4.21/Documentation/Configure.help
- --- linux-2.4.21-orig/Documentation/Configure.help 2003-06-22
15:45:55.000000000 +0000
+++ linux-2.4.21/Documentation/Configure.help 2003-06-22 14:10:39.000000000
+0000
@@ -17964,6 +17964,21 @@
<ftp://gnu.systemy.it/pub/gpm/>) solves this problem, or you can get
the "mconv2" utility from <ftp://ibiblio.org/pub/Linux/system/mouse/>.

+Disable trackpad while typing
+CONFIG_DISABLE_TRACKPAD_WHILE_TYPING
+ For people with a notebook that have a build in trackpad.
+
+ It prevents unintended mouse moves and mouse taps while typing on
+ the notebook keyboard.
+
+ The majority of notebooks on the market have a PS/2 trackpad.
+ So you will probably say "Y" if you have a notebook with a trackpad.
+
+ Also note that you can control the behaviour of the trackpad via the
+ /proc/tty/ps2-trackpad file.
+
+ See Documentation/ps2-trackpad.txt for detailed information.
+
C&T 82C710 mouse port support (as on TI Travelmate)
CONFIG_82C710_MOUSE
This is a certain kind of PS/2 mouse used on the TI Travelmate. If
diff -Naur -X dontdiff linux-2.4.21-orig/Documentation/ps2-trackpad.txt
linux-2.4.21/Documentation/ps2-trackpad.txt
- --- linux-2.4.21-orig/Documentation/ps2-trackpad.txt 1970-01-01
00:00:00.000000000 +0000
+++ linux-2.4.21/Documentation/ps2-trackpad.txt 2003-06-22 15:13:45.000000000
+0000
@@ -0,0 +1,50 @@
+For people with a notebook that have a build in trackpad.
+
+The "Disable trackpad while typing" feature prevents unintended mouse
+moves and mouse taps while typing on the notebook keyboard.
+
+The majority of notebooks on the market have a PS/2 trackpad.
+So you will probably say "Y" if you have a notebook with a trackpad.
+
+Also note that you can control the behaviour of the trackpad via the
+/proc/tty/ps2-trackpad file, e.g.
+
+Set the delay time to 2 Secs (default is 10 ==> 1 Sec)
+
+ echo "delay 20" > /proc/tty/ps2-trackpad
+
+
+Completely disable the trackpad (default 0). Useful if you plug in an
+external mouse.
+
+ echo "disable 1" > /proc/tty/ps2-trackpad
+
+To completely disable this feature use
+
+ echo "delay 0" > /proc/tty/ps2-trackpad
+
+
+Escape the keyboard keycode for the key. After these keycodes mouse
+events are passed without a delay. (defaults are the keycodes for
+CTRL, SHIFT, ALT and MS-Windows (both left and right) and Menu
+(Windows Taskbar) keys).
+
+This is useful for some applications ( like xterm ) which are using
+keydown-click events.
+
+You can use showkey -k to find out the keycodes of your own keys.
+Apply "escape ???" twice to unescape a keycode.
+
+Example: define an escape for HOME-KeyPress
+
+ echo "escape 102" > /proc/tty/ps2-trackpad
+
+If you want to escape KeyRelease events add 0x100 (256) to the actual
+keycode value.
+
+ echo "escape 358" > /proc/tty/ps2-trackpad
+
+enables mouse events immediately after releasing HOME key.
+
+I can't imagine a situation where mouse events are needed immediately
+after key release events but it's implemented for completeness.
diff -Naur -X dontdiff linux-2.4.21-orig/drivers/char/Config.in
linux-2.4.21/drivers/char/Config.in
- --- linux-2.4.21-orig/drivers/char/Config.in 2003-06-22 15:45:58.000000000
+0000
+++ linux-2.4.21/drivers/char/Config.in 2003-06-22 08:50:04.000000000 +0000
@@ -179,6 +179,13 @@
tristate 'Mouse Support (not serial and bus mice)' CONFIG_MOUSE
if [ "$CONFIG_MOUSE" != "n" ]; then
bool ' PS/2 mouse (aka "auxiliary device") support' CONFIG_PSMOUSE
+
+ if [ "$CONFIG_PSMOUSE" = "y" ]
+ then
+ bool ' Disable Trackpad while typing on Notebooks'
CONFIG_DISABLE_TRACKPAD_WHILE_TYPING
+ fi
+
+
tristate ' C&T 82C710 mouse port support (as on TI Travelmate)'
CONFIG_82C710_MOUSE
tristate ' PC110 digitizer pad support' CONFIG_PC110_PAD
tristate ' MK712 touch screen support' CONFIG_MK712_MOUSE
diff -Naur -X dontdiff linux-2.4.21-orig/drivers/char/pc_keyb.c
linux-2.4.21/drivers/char/pc_keyb.c
- --- linux-2.4.21-orig/drivers/char/pc_keyb.c 2002-11-28 23:53:12.000000000
+0000
+++ linux-2.4.21/drivers/char/pc_keyb.c 2003-06-22 15:39:21.000000000 +0000
@@ -13,6 +13,14 @@
* Code fixes to handle mouse ACKs properly.
* C. Scott Ananian <cananian@alumni.princeton.edu> 1999-01-29.
*
+ * Implemented the "disable trackpad while typing" feature. This prevents
+ * unintended mouse moves and mouse taps while typing on the keyboard on
+ * notebooks with a PS/2 trackpad.
+ * Hans-Georg Thien <1682-600@onlinehome.de> 2003-04-30.
+ *
+ * Improvements to the "disable trackpad while typing" feature.
+ * Torsten Förtsch <torsten.foertsch@gmx.net> 2003-06-20.
+ *
*/

#include <linux/config.h>
@@ -35,7 +43,7 @@
#include <linux/smp_lock.h>
#include <linux/kd.h>
#include <linux/pm.h>
- -
+#include <linux/proc_fs.h>
#include <asm/keyboard.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
@@ -102,6 +110,133 @@
#define MAX_RETRIES 60 /* some aux operations take long time*/
#endif /* CONFIG_PSMOUSE */

+#ifdef CONFIG_DISABLE_TRACKPAD_WHILE_TYPING
+
+static int trackpad_skipped_events = 0;
+static int last_kbd_event = 0; /* timestamp of last kbd event */
+static int last_kbd_scancode = 0;
+static int last_kbd_scancode_state = 0;
+static int trackpad_disable = 0;
+static int trackpad_delay = HZ; /* default delay is 1Sec */
+
+static unsigned char trackpad_escape[0x200/8]; /* 2*256-Bit vector of
keyboard scancodes to ignore */
+
+
+static int trackpad_write_proc(struct file *file,
+ const char *buf,
+ unsigned long len,
+ void *data)
+{
+
+/*
+ * handle write requests to /proc/tty/ps2-trackpad
+ */
+ char lbuf[32];
+ int tmp;
+ int success = 0;
+
+ if (len > sizeof(lbuf)-1) return -EINVAL;
+
+ if (copy_from_user(lbuf, buf, len)) return -EFAULT;
+
+ lbuf[len] = '\0';
+
+ if (sscanf(lbuf, "delay %d", &tmp)) {
+ trackpad_delay = (tmp * HZ) / 10; /* convert 1/10Sec to
jiffies */
+ success=1;
+ }
+
+ if (sscanf(lbuf, "disable %d", &tmp)) {
+ trackpad_disable = tmp ? 1 : 0;
+ success=1;
+ }
+
+ if (sscanf(lbuf, "escape %i", &tmp)) {
+ if ((tmp < 0) || (tmp >=0x200)) return -EINVAL;
+ change_bit(tmp, trackpad_escape);
+ success=1;
+ }
+
+ if (!success) return -EINVAL;
+
+ return len;
+}
+
+static int trackpad_read_proc(char *buf, char **start, off_t ofs,
+ int count, int *eof, void *data)
+{
+
+/*
+ * handle read requests to /proc/tty/ps2-trackpad
+ */
+
+ int len = 0;
+ int i;
+
+ len += sprintf(buf+len, "delay %d\n",
+ (trackpad_delay * 10) / HZ); /* convert
jiffies to 1/10Sec */
+ len += sprintf(buf+len, "disable %d\n", trackpad_disable);
+
+ for (i = 0; i < sizeof(trackpad_escape) * 8; i++) {
+ if (test_bit(i, trackpad_escape)) {
+ len += sprintf(buf+len, "escape %d\n", i);
+ }
+ }
+
+ *eof = 1;
+ buf[len+1] = '\0';
+ return len;
+}
+
+static int trackpad_config_setup(void)
+{
+
+/*
+ * create read-write entries in /proc/tty/ps2-trackpad and setup some
+ * defaults for the trackpad handling
+ */
+
+ struct proc_dir_entry *trackpad_proc_entry;
+
+ trackpad_proc_entry=create_proc_entry("tty/ps2-trackpad", 0, NULL);
+
+ if (trackpad_proc_entry == NULL) return -1;
+
+ trackpad_proc_entry->mode |= S_IWUGO;
+ trackpad_proc_entry->read_proc = trackpad_read_proc;
+ trackpad_proc_entry->write_proc = trackpad_write_proc;
+
+
+ /* set keyboard scancodes to ignore */
+ memset(trackpad_escape, 0, sizeof(trackpad_escape));
+ set_bit(0x1d, trackpad_escape); /* CTRL-L keydown */
+ set_bit(0x2a, trackpad_escape); /* SHIFT-L keydown */
+ set_bit(0x38, trackpad_escape); /* ALT-L keydown */
+
+ set_bit(0x61, trackpad_escape); /* CTRL-R keydown */
+ set_bit(0x36, trackpad_escape); /* SHIFT-R keydown */
+ set_bit(0x64, trackpad_escape); /* ALT-R keydown */
+
+ set_bit(0x7d, trackpad_escape); /* MS left WINDOWS keydown */
+ set_bit(0x7e, trackpad_escape); /* MS right WINDOWS keydown */
+ set_bit(0x7f, trackpad_escape); /* MS right MENU keydown */
+#if 0
+ set_bit(0x01, trackpad_escape); /* ESC keydown */
+ set_bit(0x66, trackpad_escape); /* HOME keydown */
+ set_bit(0x67, trackpad_escape); /* CURSORUP keydown */
+ set_bit(0x68, trackpad_escape); /* PAGEUP keydown */
+ set_bit(0x69, trackpad_escape); /* CURSOR-L keydown */
+ set_bit(0x6a, trackpad_escape); /* CURSOR-R keydown */
+ set_bit(0x6b, trackpad_escape); /* END keydown */
+ set_bit(0x6c, trackpad_escape); /* CURSORDOWN keydown */
+ set_bit(0x6d, trackpad_escape); /* PAGEDOWN keydown */
+#endif
+
+ return 0;
+}
+
+#endif /* CONFIG_DISABLE_TRACKPAD_WHILE_TYPING */
+
/*
* Wait for keyboard controller input buffer to drain.
*
@@ -449,6 +584,24 @@
return;
}

+#ifdef CONFIG_DISABLE_TRACKPAD_WHILE_TYPING
+ if (trackpad_disable) return;
+
+ if (!test_bit(last_kbd_scancode, trackpad_escape)) {
+ /* do nothing if time since last kbd event is less then trackpad_delay */
+ if (abs(jiffies - last_kbd_event) < trackpad_delay) {
+ trackpad_skipped_events++;
+ return;
+ }
+ }
+
+ if (trackpad_skipped_events%12) {
+ trackpad_skipped_events++;
+ return;
+ }
+ trackpad_skipped_events=0;
+#endif
+
prev_code = scancode;
add_mouse_randomness(scancode);
if (aux_count) {
@@ -469,6 +622,45 @@

static inline void handle_keyboard_event(unsigned char scancode)
{
+
+#ifdef CONFIG_DISABLE_TRACKPAD_WHILE_TYPING
+ /* this more or less resembles the pckbd_translate() algorithm */
+ if( scancode==0xe0 && last_kbd_scancode_state==0 ) { /* escape 1b */
+ last_kbd_scancode_state = 0x100;
+ } else if( scancode==0xe1 && last_kbd_scancode_state==0 ) { /* escape 2b */
+ last_kbd_scancode_state = 0x200;
+ } else if(last_kbd_scancode_state==0x100) {
+ /* E0 table lookup */
+ if( last_kbd_scancode = e0_keys[scancode&0x7f] ) {
+ if( scancode & 0x80 ) last_kbd_scancode|=0x100;
+ last_kbd_event = jiffies;
+ }
+ last_kbd_scancode_state=0;
+ } else if(last_kbd_scancode_state==0x200) {
+ if( (scancode&0x7f)==0x1d ) {
+ last_kbd_scancode_state++;
+ } else {
+ last_kbd_scancode_state=0; /* unknown e1 sequence */
+ }
+ } else if(last_kbd_scancode_state==0x201) {
+ if( (scancode&0x7f)==0x45 ) { /* PAUSE key */
+ last_kbd_scancode = E1_PAUSE;
+ if( scancode & 0x80 ) last_kbd_scancode|=0x100;
+ last_kbd_event = jiffies;
+ }
+ last_kbd_scancode_state=0;
+ } else {
+ last_kbd_scancode = (scancode&0x7f);
+ if( last_kbd_scancode >= SC_LIM )
+ last_kbd_scancode=high_keys[last_kbd_scancode - SC_LIM];
+ if( last_kbd_scancode ) {
+ if( scancode & 0x80 ) last_kbd_scancode|=0x100;
+ last_kbd_event = jiffies;
+ }
+ last_kbd_scancode_state=0;
+ }
+#endif
+
#ifdef CONFIG_VT
kbd_exists = 1;
if (do_acknowledge(scancode))
@@ -1219,6 +1411,10 @@
kbd_write_command(KBD_CCMD_MOUSE_DISABLE); /* Disable aux device. */
kbd_write_cmd(AUX_INTS_OFF); /* Disable controller ints. */

+#ifdef CONFIG_DISABLE_TRACKPAD_WHILE_TYPING
+ trackpad_config_setup();
+#endif
+
return 0;
}

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (GNU/Linux)

iD8DBQE+9eHLwicyCTir8T4RAg+PAJ47B2aQZEbBz50mo5++GQlQCKs5BACgnjmI
BIy+erf5vvQkEVRF5G89eB8=
=OSyM
-----END PGP SIGNATURE-----
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/