802.11 WLAN DEVICE DRIVERS DEVELOPMENT

Customer: Tier1 Semiconductor Company

Requirement: To develop device drivers for various models of WLAN chipset

Solution Provided:

• Individual drivers were developed for each model with specific host interfaces for various hardware platforms
• Designed a common driver framework supporting entire range of chipset models, host interfaces and  OS/RTOS as given below

• Hardware Architectures: x86, ARM, MIPS, XScale and OMAP
• Hardware Platforms : OMAP 1510, Intel Lubbock, Intel Bulverde,
• Host Interfaces: SDIO, SD-SPI, GSPI, USB, MSPIO, CF, CB
• Operating systems : Linux, ThreadX, REX

Approach:

• This project was executed by dedicated offshore development team based out of our R&D center in Bangalore
• In order to meet the aggressive delivery schedules, we phased out the delivery so that the initial time to get a demonstrable driver was extremely short. This was in the order of 2 – 4 weeks (depending on what was being demonstrated)
• The beta version of the driver was delivered within a time frame of 8 - 10 weeks
• Further optimization was then performed on the driver. This included using Linuxs native methods for queues and timers. Code cleanup and styling were also done in order to meet with the coding style requirements of Linux drivers.
• Additional features like re-association, roaming, IEEE Power Save and WPA were developed
  Held daily conference calls with the customer team to sort out open issues
  To prevent defect injection in to the driver, the driver was put in to sanity test before making any release, which also reduced consistent amount of re-work
• This driver was then put through vigorous quality control using 3rd party test tools as well as tools developed in-house
  A Wireless Test Lab was setup to perform sanity and full cycle tests on functionality and compatibility
• Several test scripts were being written so as to make sure that the driver sustains utmost stress
  All bugs were fixed and the driver was made production ready
• After the final release was made, driver/s was placed in maintenance mode where any additional bugs were fixed and features added on customer request. This included support for newer versions of the customers WLAN chips.
• There was also work around which was carried out at the driver so as to minimize the changes that can happen at the firmware.

Benefits:

• Time To Market – The Customer was successful in getting the solutions to the market in a quick turn around time
• The Common Driver Framework resulted in easy maintenance of code
• Portability across various Operating systems, Hardware Platforms helped the customer in easy customization of solutions

Technology & Tools:
Target Platform: x86, Xscale
RTOS/OS: Linux, WinCE, Nucleus, ThreadX, VxWorks and eCOS
Tools: GNU Tool Chain, KDB Debugger, Linux Wireless Extensions, Airopeek Packet Sniffer, Chariot Test Tool