This commit implements a character driver for the general purpose ADC of the BL808, based on the hardware scanning functionality. The driver supports setting different conversion resolutions and the order of channels to be scanned via menuconfig.
It turns out that the D0 core of the BL808 has an IRQ that represents all interrupt sources for the M0 core. This change uses this IRQ to access these sources, eliminating the need for IPC between M0 and D0.
This change implements a system for allowing the D0 core (which runs NuttX) to receive forwarded interrupts from the M0 core. This makes it possible for drivers that rely on interrupts to work with peripherals attached to the M0 core.
This PR adds support for the Bouffalo Lab BL808 SoC, based on T-Head C906 64-bit RISC-V Core. This will be used by the upcoming port of NuttX for PINE64 Ox64 SBC.
Most of the code was derived from NuttX for Star64 JH7110. The UART Driver was derived from BL602 NuttX. The source files are explained in the articles here: https://github.com/lupyuen/nuttx-ox64
`Kconfig`: Added ARCH_CHIP_BL808 for BL808 SoC
`include/bl808/chip.h`: BL808 Definitions
`include/bl808/irq.h`: External Interrupts
`src/bl808/chip.h`: Interrupt Stack Macro
`src/bl808/bl808_allocateheap.c`: Kernel Heap
`src/bl808/bl808_head.S`: Linux Header and Boot Code
`src/bl808/bl808_irq.c`: Configure Interrupts
`src/bl808/bl808_irq_dispatch.c`: Dispatch Interrupts
`src/bl808/bl808_memorymap.h`: Memory Map
`src/bl808/bl808_mm_init.c`, `bl808_mm_init.h`: Memory Mgmt
`src/bl808/bl808_pgalloc.c`: Page Allocator
`src/bl808/bl808_serial.c`, `bl808_serial.h`: UART Driver
`src/bl808/bl808_start.c`: Startup Code
`src/bl808/bl808_timerisr.c`: Timer Interrupt
`src/bl808/hardware/bl808_memorymap.h`: PLIC and UART Base Address
`src/bl808/hardware/bl808_plic.h`: PLIC Register Addresses
`src/bl808/hardware/bl808_uart.h`: UART Register Addresses
`src/bl808/Kconfig`: BL808 Config
`src/bl808/Make.defs`: Makefile
