Re: [PATCH] forced recalibration for the OLPC hgpk touchpad
From: Paul Fox <hidden>
Date: 2009-07-29 22:29:24
Also in:
lkml
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
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 <redacted> Acked-by: Andres Salomon <redacted>
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@laptop.org