NOTICE: The Processors Wiki will End-of-Life in December of 2020. It is recommended to download any files or other content you may need that are hosted on processors.wiki.ti.com. The site is now set to read only.

AM335x Touchscreen Driver's Guide

From Texas Instruments Wiki
Jump to: navigation, search
{{#switchcategory:MSP430=<McuHitboxHeader/>|C2000=<McuHitboxHeader/>|Stellaris=<McuHitboxHeader/>|TMS570=<McuHitboxHeader/>|MCU=<McuHitboxHeader/>|MAVRK=<MAVRKHitboxHeader/>|<HitboxHeader/>}}
TIBanner.png
AM335x Touchscreen Driver's Guide
Linux PSP

Introduction[edit]

Touchscreen controller on AM335x is an 8 channel general purpose ADC, with support for interleaving Touch Screen conversions for a 4-wire resistive panel. A resistive touchscreen operates by applying a voltage across a resistive network and measuring the change in resistance at a given point on the matrix where the screen is touched by an input (stylus or finger). The change in the resistance ratio marks the location on the touchscreen.

Driver Usage[edit]

Tslib[edit]

Test the working of touchscreen by using the Tslib utility. Tslib is an abstraction layer for touchscreen panel events, as well as a filter stack for the manipulation of those events. Tslib is generally used on embedded devices to provide a common user space interface to touchscreen functionality.

Environment variables[edit]

Make sure you have the following settings right.

  • export TSLIB_FBDEVICE=/dev/fb0
This is for the Fbdev device node to be used for display.
  • export TSLIB_TSDEVICE=/dev/input/touchscreen0

Execution[edit]

  • First run ts_calibrate to calibrate the touch screen.
  • You can now run ts_test application. This application helps in moving a cross-hair pattern around the LCD touchscreen. The pattern moves with your stylus movements. Also there is a draw option supported. Using your stylus you can write/draw on touchscreen.

Driver Configuration[edit]

You can enable touchscreen driver as in the kernel as follows.

Device Drivers  --->
         Input device support  --->
                  [*]  Touchscreens  --->
                           <*>   TI Touchscreen Interface

Building as Loadable Kernel Module[edit]

  • Incase if you want to build the drivers as modules, use <M> instead of <*> during menuconfig while selecting the drivers (as shown below). For more information on loadable modules refer Loadable Module HOWTO
Device Drivers  --->
         Input device support  --->
                  [*]  Touchscreens  --->
                           <M>   TI Touchscreen Interface
  • This step applies if the driver is built as module
  1. Do "make modules" to build the Touchscreen driver as module. The module should be present in "drivers/input/touchscreen/ti_tsc.ko".
  2. Load the driver using "ti_tsc.ko".
E2e.jpg {{
  1. switchcategory:MultiCore=
  • For technical support on MultiCore devices, please post your questions in the C6000 MultiCore Forum
  • For questions related to the BIOS MultiCore SDK (MCSDK), please use the BIOS Forum

Please post only comments related to the article AM335x Touchscreen Driver's Guide here.

Keystone=
  • For technical support on MultiCore devices, please post your questions in the C6000 MultiCore Forum
  • For questions related to the BIOS MultiCore SDK (MCSDK), please use the BIOS Forum

Please post only comments related to the article AM335x Touchscreen Driver's Guide here.

C2000=For technical support on the C2000 please post your questions on The C2000 Forum. Please post only comments about the article AM335x Touchscreen Driver's Guide here. DaVinci=For technical support on DaVincoplease post your questions on The DaVinci Forum. Please post only comments about the article AM335x Touchscreen Driver's Guide here. MSP430=For technical support on MSP430 please post your questions on The MSP430 Forum. Please post only comments about the article AM335x Touchscreen Driver's Guide here. OMAP35x=For technical support on OMAP please post your questions on The OMAP Forum. Please post only comments about the article AM335x Touchscreen Driver's Guide here. OMAPL1=For technical support on OMAP please post your questions on The OMAP Forum. Please post only comments about the article AM335x Touchscreen Driver's Guide here. MAVRK=For technical support on MAVRK please post your questions on The MAVRK Toolbox Forum. Please post only comments about the article AM335x Touchscreen Driver's Guide here. For technical support please post your questions at http://e2e.ti.com. Please post only comments about the article AM335x Touchscreen Driver's Guide here.

}}

Hyperlink blue.png Links

Amplifiers & Linear
Audio
Broadband RF/IF & Digital Radio
Clocks & Timers
Data Converters

DLP & MEMS
High-Reliability
Interface
Logic
Power Management

Processors

Switches & Multiplexers
Temperature Sensors & Control ICs
Wireless Connectivity

{{#switchcategory:MSP430=<McuHitboxFooter/>|C2000=<McuHitboxFooter/>|Stellaris=<McuHitboxFooter/>|TMS570=<McuHitboxFooter/>|MCU=<McuHitboxFooter/>|MAVRK=<MAVRKHitboxFooter/>|<HitboxFooter/>}}