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authorMichael Hennerich <michael.hennerich@analog.com>2010-03-09 20:38:45 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2010-03-09 22:12:45 -0800
commit06a09124b5ec65f81df66c56695d9a9ae04a0114 (patch)
tree6ae81521962ce1d013d00ae1d6915e528d8dc638 /drivers/input
parent9e49f6c1339a7972e23a335c4c71a289b4c6f65b (diff)
downloadlinux-06a09124b5ec65f81df66c56695d9a9ae04a0114.tar.gz
Input: ads7846 - add support for AD7843 parts
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@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input')
-rw-r--r--drivers/input/touchscreen/Kconfig9
-rw-r--r--drivers/input/touchscreen/ads7846.c10
2 files changed, 15 insertions, 4 deletions
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 7208654a94ae..8a8fa4d2d6a8 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 8b05d8e97543..d187be05955f 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.
 	 */