Why I did it
Some of the platform vendors use FPGA in the HW design. This FPGA is connected to the CPU via I2C bus. Adding a common module and a driver to be used for such FPGA in PDDF.
How I did it
Added 'pddf_fpgai2c_module' and 'pddf_fpgai2c_driver' kernel modules which takes the platform dependent data from PDDF JSON files and creates an I2C client for the FPGA.
How to verify it
Any platform having such an FPGA and brought up using PDDF would use these kernel modules. The detail representation of such a device in PDDF JSON file is covered in the HLD.
- Why I did it
There were compilation errors and warnings like,
/usr/src/linux-headers-5.10.0-8-2-common/scripts/Makefile.build:69: You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.
fatal error: linux/platform_data/pca954x.h: No such file or directory
hwmon_device_register() is deprecated. Please convert the driver to use hwmon_device_register_with_info().
If PDDF kernel module compilation fails, the PDDF debian package was not detecting the break.
- How I did it
Modified the code with new kernel 5.10 APIs.
Modified the Makefiles to use 'obj-m' instead of 'subdir-y'
- How to verify it
PDDF is supported on Accton platform. Load the build on AS7326 setup and check the 'dmesg'
This change introduces PDDF which is described here: https://github.com/Azure/SONiC/pull/536
Most of the platform bring up effort goes in developing the platform device drivers, SONiC platform APIs and validating them. Typically each platform vendor writes their own drivers and platform APIs which is very tailor made to that platform. This involves writing code, building, installing it on the target platform devices and testing. Many of the details of the platform are hard coded into these drivers, from the HW spec. They go through this cycle repetitively till everything works fine, and is validated before upstreaming the code.
PDDF aims to make this platform driver and platform APIs development process much simpler by providing a data driven development framework. This is enabled by:
JSON descriptor files for platform data
Generic data-driven drivers for various devices
Generic SONiC platform APIs
Vendor specific extensions for customisation and extensibility
Signed-off-by: Fuzail Khan <fuzail.khan@broadcom.com>
