From: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
The AD7873 is almost identical to the ADS7846; the only difference is
related to the Power Management bits PD0 and PD1. This results in a
slightly different PENIRQ enable behavior. For the AD7873, VREF should
be turned off during differential measurements.
So, add the AD7873/43 to the list of driver supported devices, and prevent
VREF usage during differential/ratiometric conversion modes.
Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxx>
---
drivers/input/touchscreen/Kconfig | 9 +++++----
drivers/input/touchscreen/ads7846.c | 10 ++++++++++
include/linux/spi/ads7846.h | 2 +-
3 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 480c9ac..1bc5184 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -24,17 +24,18 @@ config TOUCHSCREEN_88PM860X
module will be called 88pm860x-ts.
config TOUCHSCREEN_ADS7846
- tristate "ADS7846/TSC2046 and ADS7843 based touchscreens"
+ tristate "ADS7846/TSC2046/AD7873 and AD(S)7843 based touchscreens"
depends on SPI_MASTER
depends on HWMON = n || HWMON
help
Say Y here if you have a touchscreen interface using the
- ADS7846/TSC2046 or ADS7843 controller, and your board-specific
- setup code includes that in its table of SPI devices.
+ ADS7846/TSC2046/AD7873 or ADS7843/AD7843 controller,
+ and your board-specific setup code includes that in its
+ table of SPI devices.
If HWMON is selected, and the driver is told the reference voltage
on your board, you will also get hwmon interfaces for the voltage
- (and on ads7846/tsc2046, temperature) sensors of this chip.
+ (and on ads7846/tsc2046/ad7873, temperature) sensors of this chip.
If unsure, say N (but it's safe to say "Y").
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 8b05d8e..d187be0 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -36,6 +36,7 @@
* TSC2046 is just newer ads7846 silicon.
* Support for ads7843 tested on Atmel at91sam926x-EK.
* Support for ads7845 has only been stubbed in.
+ * Support for Analog Devices AD7873 and AD7843 tested.
*
* IRQ handling needs a workaround because of a shortcoming in handling
* edge triggered IRQs on some platforms like the OMAP1/2. These
@@ -984,6 +985,15 @@ static int __devinit ads7846_probe(struct spi_device *spi)
vref = pdata->keep_vref_on;
+ if (ts->model == 7873) {
+ /* The AD7873 is almost identical to the ADS7846
+ * keep VREF off during differential/ratiometric
+ * conversion modes
+ */
+ ts->model = 7846;
+ vref = 0;
+ }
+
/* set up the transfers to read touchscreen state; this assumes we
* use formula #2 for pressure, not #3.
*/
diff --git a/include/linux/spi/ads7846.h b/include/linux/spi/ads7846.h
index 51948eb..5710c15 100644
--- a/include/linux/spi/ads7846.h
+++ b/include/linux/spi/ads7846.h
@@ -12,7 +12,7 @@ enum ads7846_filter {
};
struct ads7846_platform_data {
- u16 model; /* 7843, 7845, 7846. */
+ u16 model; /* 7843, 7845, 7846, 7873. */
u16 vref_delay_usecs; /* 0 for external vref; etc */
u16 vref_mv; /* external vref value, milliVolts */
bool keep_vref_on; /* set to keep vref on for differential
--
1.7.0.2
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
