[pkg-fso-commits] [SCM] linux-2.6-openmoko, the Linux 2.6 kernel tree from Openmoko branch, andy-tracking, updated. upstream/20090303.gitb9de904e-140-g23b564c

[Andy Green]

The following commit has been merged in the andy-tracking branch:
commit b2ae84d8bd469fe81fa0a967fde9008416a78365
Author: Neil Brown <neilb at suse.de>
Date:   Mon Mar 9 21:01:01 2009 +0000

    (AG: there's some more rationale for changing this here
    
    http://lists.openmoko.org/pipermail/openmoko-kernel/2009-March/009387.html
    )
    
    Change accelerometers to use ABS events rather than REL events.
    
    
    [Obviously if this patch is accepted we need to tell developers about
     it.  I have a number of other improvements to the accelerometers I
     hope to deliver over the next couple of weeks.  They will have minimal
     or zero disruption to current code. ]
    
    
    REL events should be used when there is no absolute reference, and
    only changes are meaningful.  The classic example is a "mouse" where
    the absolute position of the device is not measurable and not
    particularly meaning, but change in position from one time to the next
    is interesting.
    With REL events, a value of '0' is not reported, as 'not change' is
    not interesting.
    With REL events, the expectation is that successive values will be
    eventually summed (possibly with acceleration and clipping
    adjustments) to get a usable value.
    
    ABS events should be used when there is an absolute references against
    which things that be measured.
    With ABS events, the 'current value' is meaningful and can be read
    (EVIOCGABS).
    With ABS events, the value '0' is very meaningful and is reported.
    However if consecutive values are the same, the value is only reported
    once.
    ABS events can be used as-is or compared with previous events to get
    some measure of change.
    An obvious example is a touchscreen where each measure in
    independently meaningful.
    
    Acceleration is an absolute value as it is measuring against a frame
    of reference.  '0' acceleration is just as meaningful as any other
    value, and finding the 'current' acceleration is each direction is a
    potentially useful thing to do.
    
    The Freerunner accelerometers currently report REL events.  This is
    wrong.  So this patch changes them to report ABS events.
    
    With this patch, the min/max/level/fuzz values are left at zero.  It
    might be useful to make use of these in a subsequent patch.
    min/max/level can be used to calibrate the accelerometers if accuracy
    is important.
    fuzz could possibly be used in conjunction with the 'threshold' sysfs
    value to get less frequent, lower-precision reports.
    
    This may well break some applications that read accelerometer data.
    This cannot be helped, but it is quite easy to write code that copes
    with the incorrect EV_REL events as well as the more correct and
    useful EV_ABS events.
    
    Signed-off-by: NeilBrown <neilb at suse.de>

diff --git a/drivers/input/misc/lis302dl.c b/drivers/input/misc/lis302dl.c
index 772c09c..f31e548 100644
--- a/drivers/input/misc/lis302dl.c
+++ b/drivers/input/misc/lis302dl.c
@@ -285,11 +285,11 @@ static void lis302dl_bitbang_read_sample(struct lis302dl_info *lis)
 
 	/* we have a valid sample set? */
 	if (read[0] & LIS302DL_STATUS_XYZDA) {
-		input_report_rel(lis->input_dev, REL_X, mg_per_sample *
+		input_report_abs(lis->input_dev, ABS_X, mg_per_sample *
 			    (s8)read[LIS302DL_REG_OUT_X - LIS302DL_REG_STATUS]);
-		input_report_rel(lis->input_dev, REL_Y, mg_per_sample *
+		input_report_abs(lis->input_dev, ABS_Y, mg_per_sample *
 			    (s8)read[LIS302DL_REG_OUT_Y - LIS302DL_REG_STATUS]);
-		input_report_rel(lis->input_dev, REL_Z, mg_per_sample *
+		input_report_abs(lis->input_dev, ABS_Z, mg_per_sample *
 			    (s8)read[LIS302DL_REG_OUT_Z - LIS302DL_REG_STATUS]);
 
 		input_sync(lis->input_dev);
@@ -712,15 +712,12 @@ static int __devinit lis302dl_probe(struct spi_device *spi)
 		goto bail_inp_reg;
 	}
 
-	set_bit(EV_REL, lis->input_dev->evbit);
-	set_bit(REL_X, lis->input_dev->relbit);
-	set_bit(REL_Y, lis->input_dev->relbit);
-	set_bit(REL_Z, lis->input_dev->relbit);
-/*	set_bit(EV_KEY, lis->input_dev->evbit);
-	set_bit(BTN_X, lis->input_dev->keybit);
-	set_bit(BTN_Y, lis->input_dev->keybit);
-	set_bit(BTN_Z, lis->input_dev->keybit);
-*/
+	set_bit(EV_ABS, lis->input_dev->evbit);
+	input_set_abs_params(lis->input_dev, ABS_X, 0, 0, 0, 0);
+	input_set_abs_params(lis->input_dev, ABS_Y, 0, 0, 0, 0);
+	input_set_abs_params(lis->input_dev, ABS_Z, 0, 0, 0, 0);
+	
+
 	lis->threshold = 0;
 	lis->duration = 0;
 	memset(&lis->wakeup, 0, sizeof(lis->wakeup));

-- 
linux-2.6-openmoko, the Linux 2.6 kernel tree from Openmoko