Re: ads7846 touchscreen: fix pressure

Pavel Machek
2009-11-20T18:51:06Z

Hi!

> > On Zaurus, pressure is reported inverted -- the lighter the pressure,
> > the bigger numerical value. This should fix it.
> >
>
> Thanks. Didn't you also have a bigger cleanup patch for ads7846?

Yes, I did, but I wanted to avoid risk for collision. So pick one...

--

Cleanup touchscreen driver and fix pressure on spitz.

Signed-off-by: Pavel Machek <pavel@ucw.cz>

--- linux-rc/drivers/input/touchscreen/ads7846.c 2009-10-06 13:49:56.000000000 +0200
+++ linux-rc/drivers/input/touchscreen/ads7846.c 2009-10-06 21:18:25.000000000 +0200
@@ -29,10 +29,14 @@
#include <linux/spi/ads7846.h>
#include <asm/irq.h>

+#ifndef VERBOSE
+#undef dev_dbg
+#define dev_dbg(...) do {} while(0)
+#endif

/*
* This code has been heavily tested on a Nokia 770, and lightly
- * tested on other ads7846 devices (OSK/Mistral, Lubbock).
+ * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
* TSC2046 is just newer ads7846 silicon.
* Support for ads7843 tested on Atmel at91sam926x-EK.
* Support for ads7845 has only been stubbed in.
@@ -43,7 +47,7 @@
* have to maintain our own SW IRQ disabled status. This should be
* removed as soon as the affected platform's IRQ handling is fixed.
*
- * app note sbaa036 talks in more detail about accurate sampling...
+ * App note sbaa036 talks in more detail about accurate sampling...
* that ought to help in situations like LCDs inducing noise (which
* can also be helped by using synch signals) and more generally.
* This driver tries to utilize the measures described in the app
@@ -566,10 +570,8 @@
* once more the measurement
*/
if (packet->tc.ignore || Rt > ts->pressure_max) {
-#ifdef VERBOSE
- pr_debug("%s: ignored %d pressure %d\n",
- dev_name(&ts->spi->dev), packet->tc.ignore, Rt);
-#endif
+ dev_dbg(&ts->spi->dev, "ignored %d pressure %d\n",
+ packet->tc.ignore, Rt);
hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
HRTIMER_MODE_REL);
return;
@@ -584,10 +586,11 @@
Rt = 0;
}

- /* NOTE: We can't rely on the pressure to determine the pen down
- * state, even this controller has a pressure sensor. The pressure
- * value can fluctuate for quite a while after lifting the pen and
- * in some cases may not even settle at the expected value.
+ /* NOTE: We can't rely on the pressure to determine the pen
+ * down state, not even if this controller has a pressure
+ * sensor. The pressure value can fluctuate for quite a while
+ * after lifting the pen and in some cases may not even settle
+ * at the expected value.
*
* The only safe way to check for the pen up condition is in the
* timer by reading the pen signal state (it's a GPIO _and_ IRQ).
@@ -598,9 +601,7 @@
if (!ts->pendown) {
input_report_key(input, BTN_TOUCH, 1);
ts->pendown = 1;
-#ifdef VERBOSE
dev_dbg(&ts->spi->dev, "DOWN\n");
-#endif
}

if (ts->swap_xy)
@@ -608,12 +609,10 @@

input_report_abs(input, ABS_X, x);
input_report_abs(input, ABS_Y, y);
- input_report_abs(input, ABS_PRESSURE, Rt);
+ input_report_abs(input, ABS_PRESSURE, ts->pressure_max-Rt);

input_sync(input);
-#ifdef VERBOSE
dev_dbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
-#endif
}

hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
@@ -723,9 +722,7 @@
input_sync(input);

ts->pendown = 0;
-#ifdef VERBOSE
dev_dbg(&ts->spi->dev, "UP\n");
-#endif
}

/* measurement cycle ended */