HSTX Support for RP2350 #17111

Description

Would love for the RP2350's HSTX peripheral to be available in MicroPython! It provides an interface for outputting data ludicrously fast (8 GPIO pins (GPIO 12-19 only), DDR on each clock cycle, so up to 2.4Gbps without any overclocking), very useful for things like displays. Would be a part of the rp2 module, only on RP2350 boards (not supported on RP2040).

Section 12.11 of the RP2350 datasheet provides more details about the hardware. There are also a couple examples from the pico-examples repo.

As I understand it, basically just need to gpio_set_function(<GPIO 12-19>, GPIO_FUNC_HSTX), configure the hardware peripheral hstx_ctrl_hw (from hardware/structs/hstx_ctrl.h using macros from hardware/regs/hstx_ctrl.h), then send data to the FIFO buffer hstx_fifo_hw (from hardware/structs/hstx_fifo.h using macros from hardware/regs/hstx_fifo.h). I believe it's also possible to have the DMA feed the HSTX FIFO, DREQ_HSTX is a member of the DMA's dreq_num_rp2350, which should be made available in MicroPython.

Code Size

IMO this should always be enabled for RP2350 boards as part of the rp2 module, similar to the PIO and DMA features. Not expecting it to be very large.

Implementation

I hope the MicroPython maintainers or community will implement this feature

Code of Conduct

Yes, I agree