From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Gavin Li <gavinli@thegavinli.com>
Cc: linux-input@vger.kernel.org, Gavin Li <git@thegavinli.com>
Subject: Re: [PATCH] atkbd: add basic debounce support
Date: Mon, 13 Jul 2015 10:20:53 -0700 [thread overview]
Message-ID: <20150713172053.GE5039@dtor-ws> (raw)
In-Reply-To: <1436772972-26919-1-git-send-email-gavinli@thegavinli.com>
Hi Gavin,
On Mon, Jul 13, 2015 at 12:36:12AM -0700, Gavin Li wrote:
> From: Gavin Li <git@thegavinli.com>
>
> For physically quirky or otherwise poor keyboards.
It would be nice to know what keyboards have this issue? It is
widespread problem or just a single unit misbehaving?
Thanks.
> ---
> 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
>
--
Dmitry
next prev parent reply other threads:[~2015-07-13 17:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-13 7:36 [PATCH] atkbd: add basic debounce support Gavin Li
2015-07-13 17:20 ` Dmitry Torokhov [this message]
2015-07-14 6:04 ` Gavin Li
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