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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
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+* TI - TSC ADC (Touschscreen and analog digital converter)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Required properties:
+- child "tsc"
+ ti,wires: Wires refer to application modes i.e. 4/5/8 wire touchscreen
+ support on the platform.
+ ti,x-plate-resistance: X plate resistance
+ ti,coordinate-readouts: The sequencer supports a total of 16
+ programmable steps each step is used to
+ read a single coordinate. A single
+ readout is enough but multiple reads can
+ increase the quality.
+ A value of 5 means, 5 reads for X, 5 for
+ Y and 2 for Z (always). This utilises 12
+ of the 16 software steps available. The
+ remaining 4 can be used by the ADC.
+ ti,wire-config: Different boards could have a different order for
+ connecting wires on touchscreen. We need to provide an
+ 8 bit number where in the 1st four bits represent the
+ analog lines and the next 4 bits represent positive/
+ negative terminal on that input line. Notations to
+ represent the input lines and terminals resoectively
+ is as follows:
+ AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
+ XP = 0, XN = 1, YP = 2, YN = 3.
+- child "adc"
+ ti,adc-channels: List of analog inputs available for ADC.
+ AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
+
+Optional properties:
+- child "tsc"
+ ti,charge-delay: Length of touch screen charge delay step in terms of
+ ADC clock cycles. Charge delay value should be large
+ in order to avoid false pen-up events. This value
+ effects the overall sampling speed, hence need to be
+ kept as low as possible, while avoiding false pen-up
+ event. Start from a lower value, say 0x400, and
+ increase value until false pen-up events are avoided.
+ The pen-up detection happens immediately after the
+ charge step, so this does in fact function as a
+ hardware knob for adjusting the amount of "settling
+ time".
+
+Example:
+ tscadc: tscadc@44e0d000 {
+ compatible = "ti,am3359-tscadc";
+ tsc {
+ ti,wires = <4>;
+ ti,x-plate-resistance = <200>;
+ ti,coordiante-readouts = <5>;
+ ti,wire-config = <0x00 0x11 0x22 0x33>;
+ ti,charge-delay = <0x400>;
+ };
+
+ adc {
+ ti,adc-channels = <4 5 6 7>;
+ };
+ }