summaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/input/touchscreen/ads7846.txt
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-03 12:38:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-03 12:38:20 -0700
commit16a12fa9aed176444fc795b09e796be41902bb08 (patch)
treebd158def3263a8b0d0f0886fd0fcd32728242dc4 /Documentation/devicetree/bindings/input/touchscreen/ads7846.txt
parentd25e436c4b68db2895185b24ad1f22499c2f87b0 (diff)
parent0337966d121ebebf73a1c346123e8112796e684e (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input subsystem updates from Dmitry Torokhov: - a big update from Mauro converting input documentation to ReST format - Synaptics PS/2 is now aware of SMBus companion devices, which means that we can now use native RMI4 protocol to handle touchpads, instead of relying on legacy PS/2 mode. - we removed support from BMA180 accelerometer from input devices as it is now handled properly by IIO - update to TSC2007 to corretcly report pressure - other miscellaneous driver fixes. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (152 commits) Input: ar1021_i2c - use BIT to check for a bit Input: twl4030-pwrbutton - use input_set_capability() helper Input: twl4030-pwrbutton - use correct device for irq request Input: ar1021_i2c - enable touch mode during open Input: add uinput documentation dt-bindings: input: add bindings document for ar1021_i2c driver dt-bindings: input: rotary-encoder: fix typo Input: xen-kbdfront - add module parameter for setting resolution ARM: pxa/raumfeld: fix compile error in rotary controller resources Input: xpad - do not suggest writing to Dominic Input: xpad - don't use literal blocks inside footnotes Input: xpad - note that usb/devices is now at /sys/kernel/debug/ Input: docs - freshen up introduction Input: docs - split input docs into kernel- and user-facing Input: docs - note that MT-A protocol is obsolete Input: docs - update joystick documentation a bit Input: docs - remove disclaimer/GPL notice Input: fix "Game console" heading level in joystick documentation Input: rotary-encoder - remove references to platform data from docs Input: move documentation for Amiga CD32 ...
Diffstat (limited to 'Documentation/devicetree/bindings/input/touchscreen/ads7846.txt')
-rw-r--r--Documentation/devicetree/bindings/input/touchscreen/ads7846.txt94
1 files changed, 94 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/input/touchscreen/ads7846.txt b/Documentation/devicetree/bindings/input/touchscreen/ads7846.txt
new file mode 100644
index 000000000000..9fc47b006fd1
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/ads7846.txt
@@ -0,0 +1,94 @@
+Device tree bindings for TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046
+SPI driven touch screen controllers.
+
+The node for this driver must be a child node of a SPI controller, hence
+all mandatory properties described in
+
+ Documentation/devicetree/bindings/spi/spi-bus.txt
+
+must be specified.
+
+Additional required properties:
+
+ compatible Must be one of the following, depending on the
+ model:
+ "ti,tsc2046"
+ "ti,ads7843"
+ "ti,ads7845"
+ "ti,ads7846"
+ "ti,ads7873"
+
+ interrupt-parent
+ interrupts An interrupt node describing the IRQ line the chip's
+ !PENIRQ pin is connected to.
+ vcc-supply A regulator node for the supply voltage.
+
+
+Optional properties:
+
+ ti,vref-delay-usecs vref supply delay in usecs, 0 for
+ external vref (u16).
+ ti,vref-mv The VREF voltage, in millivolts (u16).
+ Set to 0 to use internal references
+ (ADS7846).
+ ti,keep-vref-on set to keep vref on for differential
+ measurements as well
+ ti,swap-xy swap x and y axis
+ ti,settle-delay-usec Settling time of the analog signals;
+ a function of Vcc and the capacitance
+ on the X/Y drivers. If set to non-zero,
+ two samples are taken with settle_delay
+ us apart, and the second one is used.
+ ~150 uSec with 0.01uF caps (u16).
+ ti,penirq-recheck-delay-usecs If set to non-zero, after samples are
+ taken this delay is applied and penirq
+ is rechecked, to help avoid false
+ events. This value is affected by the
+ material used to build the touch layer
+ (u16).
+ ti,x-plate-ohms Resistance of the X-plate,
+ in Ohms (u16).
+ ti,y-plate-ohms Resistance of the Y-plate,
+ in Ohms (u16).
+ ti,x-min Minimum value on the X axis (u16).
+ ti,y-min Minimum value on the Y axis (u16).
+ ti,x-max Maximum value on the X axis (u16).
+ ti,y-max Minimum value on the Y axis (u16).
+ ti,pressure-min Minimum reported pressure value
+ (threshold) - u16.
+ ti,pressure-max Maximum reported pressure value (u16).
+ ti,debounce-max Max number of additional readings per
+ sample (u16).
+ ti,debounce-tol Tolerance used for filtering (u16).
+ ti,debounce-rep Additional consecutive good readings
+ required after the first two (u16).
+ ti,pendown-gpio-debounce Platform specific debounce time for the
+ pendown-gpio (u32).
+ pendown-gpio GPIO handle describing the pin the !PENIRQ
+ line is connected to.
+ wakeup-source use any event on touchscreen as wakeup event.
+ (Legacy property support: "linux,wakeup")
+
+
+Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC::
+
+ spi_controller {
+ tsc2046@0 {
+ reg = <0>; /* CS0 */
+ compatible = "ti,tsc2046";
+ interrupt-parent = <&gpio1>;
+ interrupts = <8 0>; /* BOOT6 / GPIO 8 */
+ spi-max-frequency = <1000000>;
+ pendown-gpio = <&gpio1 8 0>;
+ vcc-supply = <&reg_vcc3>;
+
+ ti,x-min = /bits/ 16 <0>;
+ ti,x-max = /bits/ 16 <8000>;
+ ti,y-min = /bits/ 16 <0>;
+ ti,y-max = /bits/ 16 <4800>;
+ ti,x-plate-ohms = /bits/ 16 <40>;
+ ti,pressure-max = /bits/ 16 <255>;
+
+ wakeup-source;
+ };
+ };