1.The dummy_bits is set to 4 in ESP32C3/C2, therefore, the data transmission started too early.This commit fix this issue by changing dummy_bits to 8.
2.Put the spi command the spi defintion in spi_types.h
3.Put the function which get spi command or dummy bits in spi_ll.h
update all struct headers to be more "standardized":
- bit fields are properly wrapped with struct
- bitwidth sum should be 32 within same struct, so that it's correctly padded with reserved bits
- bit field should be uint32_t
- typedef volatile struct xxx{} yyy;: xxx must exists. refer: https://github.com/espressif/esp-idf/pull/3199
added helper macros to force peripheral registers being accessed in 32 bitwidth
added a check script into ci
The user can now request the chip select to remain active after the current
transfer. In order to do so, he MUST acquire the bus first with `spi_device_acquire_bus()`
function, else, an error is returned.
