From: Gavin Li <git@xxxxxxxxxxxxxx>
For physically quirky or otherwise poor keyboards.
---
drivers/input/keyboard/atkbd.c | 69 +++++++++++++++++++++++++++++++++---------
1 file changed, 54 insertions(+), 15 deletions(-)
diff --git a/drivers/input/keyboard/atkbd.c b/drivers/input/keyboard/atkbd.c
index 387c51f..b1ff62d 100644
--- a/drivers/input/keyboard/atkbd.c
+++ b/drivers/input/keyboard/atkbd.c
@@ -28,6 +28,7 @@
#include <linux/libps2.h>
#include <linux/mutex.h>
#include <linux/dmi.h>
+#include <linux/timekeeping.h>
#define DRIVER_DESC "AT and PS/2 keyboard driver"
@@ -67,6 +68,10 @@ static bool atkbd_terminal;
module_param_named(terminal, atkbd_terminal, bool, 0);
MODULE_PARM_DESC(terminal, "Enable break codes on an IBM Terminal keyboard connected via AT/PS2");
+static int atkbd_debounce;
+module_param_named(debounce, atkbd_debounce, int, 0);
+MODULE_PARM_DESC(debounce, "Milliseconds to debounce successive keys");
+
/*
* Scancode to keycode tables. These are just the default setting, and
* are loadable via a userland utility.
@@ -218,6 +223,7 @@ struct atkbd {
bool softraw;
bool scroll;
bool enabled;
+ ktime_t debounce_ktime;
/* Accessed only from interrupt */
unsigned char emul;
@@ -227,6 +233,9 @@ struct atkbd {
unsigned int last;
unsigned long time;
unsigned long err_count;
+ bool is_debouncing;
+ unsigned short last_debounce_code;
+ ktime_t last_debounce_expiration;
struct delayed_work event_work;
unsigned long event_jiffies;
@@ -375,7 +384,7 @@ static irqreturn_t atkbd_interrupt(struct serio *serio, unsigned char data,
struct atkbd *atkbd = serio_get_drvdata(serio);
struct input_dev *dev = atkbd->dev;
unsigned int code = data;
- int scroll = 0, hscroll = 0, click = -1;
+ int scroll = 0, hscroll = 0, keypress = 0, click = -1;
int value;
unsigned short keycode;
@@ -456,23 +465,9 @@ static irqreturn_t atkbd_interrupt(struct serio *serio, unsigned char data,
keycode = atkbd->keycode[code];
- if (!(atkbd->release && test_bit(code, atkbd->force_release_mask)))
- if (keycode != ATKBD_KEY_NULL)
- input_event(dev, EV_MSC, MSC_SCAN, code);
-
switch (keycode) {
case ATKBD_KEY_NULL:
- break;
case ATKBD_KEY_UNKNOWN:
- dev_warn(&serio->dev,
- "Unknown key %s (%s set %d, code %#x on %s).\n",
- atkbd->release ? "released" : "pressed",
- atkbd->translated ? "translated" : "raw",
- atkbd->set, code, serio->phys);
- dev_warn(&serio->dev,
- "Use 'setkeycodes %s%02x <keycode>' to make it known.\n",
- code & 0x80 ? "e0" : "", code & 0x7f);
- input_sync(dev);
break;
case ATKBD_SCR_1:
scroll = 1;
@@ -496,6 +491,7 @@ static irqreturn_t atkbd_interrupt(struct serio *serio, unsigned char data,
hscroll = 1;
break;
default:
+ keypress = 1;
if (atkbd->release) {
value = 0;
atkbd->last = 0;
@@ -507,7 +503,49 @@ static irqreturn_t atkbd_interrupt(struct serio *serio, unsigned char data,
atkbd->last = code;
atkbd->time = jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]) / 2;
}
+ }
+
+ if (keypress) {
+ if (atkbd->is_debouncing && code == atkbd->last_debounce_code) {
+ /* ignore debounced release/repeat event */
+ if (value == 0) {
+ atkbd->is_debouncing = false;
+ atkbd->release = false;
+ }
+ goto out;
+ }
+ if (!atkbd->is_debouncing && value == 1) {
+ ktime_t now = ktime_get();
+ if (code == atkbd->last_debounce_code &&
+ ktime_before(now, atkbd->last_debounce_expiration)) {
+ /* debounce the press event */
+ dev_dbg(&serio->dev, "Debounced scan code %#x.\n", code);
+ atkbd->is_debouncing = !test_bit(code, atkbd->force_release_mask);
+ goto out;
+ } else {
+ atkbd->last_debounce_code = code;
+ atkbd->last_debounce_expiration = ktime_add(now, atkbd->debounce_ktime);
+ }
+ }
+ }
+
+ if (keycode != ATKBD_KEY_NULL)
+ if (!(atkbd->release && test_bit(code, atkbd->force_release_mask)))
+ input_event(dev, EV_MSC, MSC_SCAN, code);
+
+ if (keycode == ATKBD_KEY_UNKNOWN) {
+ dev_warn(&serio->dev,
+ "Unknown key %s (%s set %d, code %#x on %s).\n",
+ atkbd->release ? "released" : "pressed",
+ atkbd->translated ? "translated" : "raw",
+ atkbd->set, code, serio->phys);
+ dev_warn(&serio->dev,
+ "Use 'setkeycodes %s%02x <keycode>' to make it known.\n",
+ code & 0x80 ? "e0" : "", code & 0x7f);
+ input_sync(dev);
+ }
+ if (keypress) {
input_event(dev, EV_KEY, keycode, value);
input_sync(dev);
@@ -1161,6 +1199,7 @@ static int atkbd_connect(struct serio *serio, struct serio_driver *drv)
atkbd->softraw = atkbd_softraw;
atkbd->softrepeat = atkbd_softrepeat;
atkbd->scroll = atkbd_scroll;
+ atkbd->debounce_ktime = ms_to_ktime(max(atkbd_debounce, 0));
if (atkbd->softrepeat)
atkbd->softraw = true;
--
2.4.5
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