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Date: Wed, 29 Jul 2009 18:08:50 -0400
From: Paul Fox <pgf@...top.org>
To: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] forced recalibration for the OLPC hgpk touchpad
this is a resubmission, in the hopes of jump-starting the merge
discussion. it was last discussed in early june of this year.
the OLPC XO laptop incorporates a combination touchpad/tablet
device which unfortunately requires frequent recalibration. the
driver will force this automatically when various suspicious
behaviors are observed, and the user can recalibrate manually
(with a special keyboard sequence). there's currently no way,
however, for an external program to cause recalibration.
this patch creates a new node in /sys which, when written with '1',
will force a touchpad recalibration. no other writes (or reads)
of this node are supported.
during the previous discussion, dmitry suggested that we instead
use the reconnect capability which is already available in /sys.
i experimented with this, and unfortunately a full reset of
the touchpad takes quite a long time -- 1.1 or 1.2 seconds.
recalibration deprives the user of their touchpad for long enough
as it is -- i don't think we can afford that time. (note
that this is a workaround for bad hardware -- the XO no longer
uses this touchpad at least partly due to this very issue, but
there are enough in use that we're still trying to improve
things.)
paul
Signed-off-by: Paul Fox <pgf@...top.org>
Acked-by: Andres Salomon <dilinger@...labora.co.uk>
diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
index a1ad2f1..e736ebd 100644
--- a/drivers/input/mouse/hgpk.c
+++ b/drivers/input/mouse/hgpk.c
@@ -369,12 +369,40 @@ static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
__PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
hgpk_show_powered, hgpk_set_powered, 0);
+static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
+ void *data, char *buf)
+{
+ return -EINVAL;
+}
+
+static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data,
+ const char *buf, size_t count)
+{
+ struct hgpk_data *priv = psmouse->private;
+ unsigned long value;
+ int err;
+
+ err = strict_strtoul(buf, 10, &value);
+ if (err || value != 1)
+ return -EINVAL;
+
+ psmouse_queue_work(psmouse, &priv->recalib_wq,
+ msecs_to_jiffies(1));
+
+ return count;
+}
+
+__PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL,
+ hgpk_trigger_recal_show, hgpk_trigger_recal, 0);
+
static void hgpk_disconnect(struct psmouse *psmouse)
{
struct hgpk_data *priv = psmouse->private;
device_remove_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
+ device_remove_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_recalibrate.dattr);
psmouse_reset(psmouse);
kfree(priv);
}
@@ -423,8 +451,18 @@ static int hgpk_register(struct psmouse *psmouse)
err = device_create_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
- if (err)
- hgpk_err(psmouse, "Failed to create sysfs attribute\n");
+ if (err) {
+ hgpk_err(psmouse, "Failed creating 'powered' sysfs node\n");
+ } else {
+ err = device_create_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_recalibrate.dattr);
+ if (err) {
+ hgpk_err(psmouse,
+ "Failed creating 'recalibrate' sysfs node\n");
+ device_remove_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_powered.dattr);
+ }
+ }
return err;
}
=---------------------
paul fox, pgf@...top.org
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