STM Linux Device Driver

Linux Device Driver for STM

• Linux kernel module device driver enables applications to use MIPI STM as a standard character device driver.
  • No modifications to application code.
  • No hardware knowledge needed: just use it like a standard device
    • i.e. “cat file.txt > /dev/stm1”
  • Device is accessed through standard Linux file system node – i.e. /dev/*
• Linux device driver supports:
  • Configuration for MIPI STM base address and resolution
  • 255 STM channels (0 – 254)
  • Multiple STM channels are accessible simultaneously from software
  • Device accessed as a stream of bytes
• Driver is a kernel module (i.e. outside of the kernel binary)
  • Loadable device module (added/removed at runtime).
  • Binary and source code provided for re-build (if needed)

How to build and run the STM Linux driver for Android on Blaze

• To build for Android (2.6.32) kernel:

• Follow the steps in the README.txt file to build the kernel module.

• To install the kernel module on the Blaze board running Android:

• You need to first install the busybox command line tools. See this article.
• Following the instructions in the README.txt on how to install the kernel module.

Demo

• Video demo for loading and capturing STM contents:STM Linux Driver Video

Note: You would need Adobe Shockwave player/plugin to play this video.

Example Use

• The data contents can be re-directed to STM channel, e.g.,

     /home/usr1>ls -l > /dev/stm1

• Alternatively, the application can open a handle to the device for better control of data flow over specific STM channels, e.g.

     fd1 = open("/dev/stm1", O_WRONLY);  /* STM channel 1 for thread1 */

     /* in thread1, send data over dedicated channel */
     strcpy(data1, "From STM test application – thread1.\n");
     rtn = write(fd1, data1, strlen(data1));

Status and Download

• STM Linux driver source and module files.GForge
  • Note: The attached driver module is built from kernel version: Linux-2.6.33-rc2. Please rebuild the STM driver module for any other versions.

Hints and Tips

• If you notice that there are some messages missing, please check your memory settings for STM port (for example, for Omap4430, it is start at 0x54000000).
• Please disable cache and buffering for STM port in Linux.