From 6680884a44207efe8ef6bc56b1c932cce2b89994 Mon Sep 17 00:00:00 2001
From: Michael Hennerich <michael.hennerich@analog.com>
Date: Fri, 6 Jul 2012 10:44:19 -0700
Subject: [PATCH] Input: ad7879 - add option to correct xy axis
Sebastian Zenker reported that driver swaps x and y samples when the
touchscreen leads are connected in accordance with the datasheet
specification. Transposed axis can be typically corrected by touch
screen calibration however this bug also negatively influences touch
pressure measurements.
Add an option to correct x and y axis.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Reported-and-tested-by: Sebastian Zenker <sebastian.zenker@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/input/touchscreen/ad7879.c | 5 +++++
include/linux/spi/ad7879.h | 2 ++
2 files changed, 7 insertions(+)
diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
index e2482b40da519..e60709261951a 100644
--- a/drivers/input/touchscreen/ad7879.c
+++ b/drivers/input/touchscreen/ad7879.c
@@ -118,6 +118,7 @@ struct ad7879 {
unsigned int irq;
bool disabled; /* P: input->mutex */
bool suspended; /* P: input->mutex */
+ bool swap_xy;
u16 conversion_data[AD7879_NR_SENSE];
char phys[32];
u8 first_conversion_delay;
@@ -161,6 +162,9 @@ static int ad7879_report(struct ad7879 *ts)
z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
+ if (ts->swap_xy)
+ swap(x, y);
+
/*
* The samples processed here are already preprocessed by the AD7879.
* The preprocessing function consists of a median and an averaging
@@ -520,6 +524,7 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
ts->dev = dev;
ts->input = input_dev;
ts->irq = irq;
+ ts->swap_xy = pdata->swap_xy;
setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
diff --git a/include/linux/spi/ad7879.h b/include/linux/spi/ad7879.h
index 6334cee1a3be6..58368be0b4c07 100644
--- a/include/linux/spi/ad7879.h
+++ b/include/linux/spi/ad7879.h
@@ -12,6 +12,8 @@ struct ad7879_platform_data {
u16 y_min, y_max;
u16 pressure_min, pressure_max;
+ bool swap_xy; /* swap x and y axes */
+
/* [0..255] 0=OFF Starts at 1=550us and goes
* all the way to 9.440ms in steps of 35us.
*/
--
2.30.2