[pddf]: Adding support for FPGAPCIe in PDDF (#13476)

Why I did it
Some of the platform vendors use FPGA in the HW design. This FPGA is connected to the CPU via PCIe interface. This FPGA also works as an I2C controller having other devices attached to the I2C channels emanating from it. Adding a common module, a driver and a platform specific algorithm module to be used for such FPGA in PDDF.

How I did it
Added 'pddf_fpgapci_module', 'pddf_fpgapci_driver' and a sample algorithm module for Xilinx device 7021. Kernel modules which takes the platform dependent data from PDDF JSON files and initialises the PCIe FPGA. The sample algorithm module can be used by the ODMs in case the communication algorithms are same for their device. Else, they need to come up with similar algo module.

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.

platform/pddf/i2c/debian/rules

@@ -18,7 +18,7 @@ PACKAGE_PRE_NAME := sonic-platform-pddf
 KVERSION   ?= $(shell uname -r)
 KERNEL_SRC :=  /lib/modules/$(KVERSION)
 MOD_SRC_DIR:= $(shell pwd)
-MODULE_DIRS:= client cpld cpld/driver cpldmux cpldmux/driver fpgai2c fpgai2c/driver fan fan/driver mux gpio led psu psu/driver sysstatus xcvr xcvr/driver
+MODULE_DIRS:= client cpld cpld/driver cpldmux cpldmux/driver fpgai2c fpgai2c/driver fpgapci fpgapci/driver fpgapci/algos fan fan/driver mux gpio led psu psu/driver sysstatus xcvr xcvr/driver
 MODULE_DIR:= modules
 UTILS_DIR := utils
 SERVICE_DIR := service

platform/pddf/i2c/modules/Makefile

@@ -1 +1 @@
-obj-m := client/ cpld/ cpldmux/ fpgai2c/ xcvr/ mux/ gpio/ psu/ fan/ led/ sysstatus/
+obj-m := client/ cpld/ cpldmux/ fpgai2c/ fpgapci/ xcvr/ mux/ gpio/ psu/ fan/ led/ sysstatus/

platform/pddf/i2c/modules/fpgapci/Makefile

@@ -0,0 +1,4 @@
+obj-m := driver/ algos/
+obj-m += pddf_fpgapci_module.o
+
+ccflags-y:= -I$(M)/modules/include

platform/pddf/i2c/modules/fpgapci/algos/Makefile

@@ -0,0 +1,4 @@
+# Sample driver for Xilinx 7021 FPGA device
+obj-m += pddf_xilinx_device_7021_algo.o
+
+ccflags-y := -I$(M)/modules/include