Input: ads7846 - optionally leave Vref on during differential measurements
On some LCDs leaving the Vref on provides much better readings.
Signed-off-by: Jarkko Oikarinen <jarkko.oikarinen@nokia.com>
Signed-off-by: Imre Deak <imre.deak@solidboot.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/include/linux/spi/ads7846.h b/include/linux/spi/ads7846.h
index 1663f94..3387e44 100644
--- a/include/linux/spi/ads7846.h
+++ b/include/linux/spi/ads7846.h
@@ -14,6 +14,8 @@
struct ads7846_platform_data {
u16 model; /* 7843, 7845, 7846. */
u16 vref_delay_usecs; /* 0 for external vref; etc */
+ int keep_vref_on:1; /* set to keep vref on for differential
+ * measurements as well */
u16 x_plate_ohms;
u16 y_plate_ohms;