/* * This file is part of the MicroPython project, http://micropython.org/ * * The MIT License (MIT) * * Copyright (c) 2021 Scott Shawcroft for Adafruit Industries * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "bindings/rp2pio/StateMachine.h" #include "common-hal/microcontroller/__init__.h" #include "shared-bindings/microcontroller/Pin.h" #include "src/rp2040/hardware_regs/include/hardware/platform_defs.h" #include "src/rp2_common/hardware_clocks/include/hardware/clocks.h" #include "src/rp2_common/hardware_dma/include/hardware/dma.h" #include "src/rp2_common/hardware_pio/include/hardware/pio_instructions.h" #include "src/rp2040/hardware_structs/include/hardware/structs/iobank0.h" #include "lib/utils/interrupt_char.h" #include "py/obj.h" #include "py/objproperty.h" #include "py/runtime.h" // Count how many state machines are using each pin. STATIC uint8_t _pin_reference_count[TOTAL_GPIO_COUNT]; STATIC uint32_t _current_program_id[NUM_PIOS][NUM_PIO_STATE_MACHINES]; STATIC uint8_t _current_program_offset[NUM_PIOS][NUM_PIO_STATE_MACHINES]; STATIC uint8_t _current_program_len[NUM_PIOS][NUM_PIO_STATE_MACHINES]; STATIC bool _never_reset[NUM_PIOS][NUM_PIO_STATE_MACHINES]; STATIC uint32_t _current_pins[NUM_PIOS]; STATIC uint32_t _current_sm_pins[NUM_PIOS][NUM_PIO_STATE_MACHINES]; STATIC PIO pio_instances[2] = {pio0, pio1}; void _reset_statemachine(PIO pio, uint8_t sm, bool leave_pins) { uint8_t pio_index = pio_get_index(pio); uint32_t program_id = _current_program_id[pio_index][sm]; if (program_id == 0) { return; } _current_program_id[pio_index][sm] = 0; bool program_in_use = false; for (size_t i = 0; i < NUM_PIO_STATE_MACHINES; i++) { if (_current_program_id[pio_index][i] == program_id) { program_in_use = true; break; } } if (!program_in_use) { uint8_t offset = _current_program_offset[pio_index][sm]; pio_program_t program_struct = { .length = _current_program_len[pio_index][sm] }; pio_remove_program(pio, &program_struct, offset); } uint32_t pins = _current_sm_pins[pio_index][sm]; for (size_t pin_number = 0; pin_number < TOTAL_GPIO_COUNT; pin_number++) { if ((pins & (1 << pin_number)) == 0) { continue; } _pin_reference_count[pin_number]--; if (_pin_reference_count[pin_number] == 0) { if (!leave_pins) { reset_pin_number(pin_number); } _current_pins[pio_index] &= ~(1 << pin_number); } } _current_sm_pins[pio_index][sm] = 0; pio_sm_unclaim(pio, sm); } void reset_rp2pio_statemachine(void) { for (size_t i = 0; i < NUM_PIOS; i++) { PIO pio = pio_instances[i]; for (size_t j = 0; j < NUM_PIO_STATE_MACHINES; j++) { if (_never_reset[i][j]) { continue; } _reset_statemachine(pio, j, false); } } } STATIC uint32_t _check_pins_free(const mcu_pin_obj_t * first_pin, uint8_t pin_count, bool exclusive_pin_use) { uint32_t pins_we_use = 0; if (first_pin != NULL) { for (size_t i = 0; i < pin_count; i++) { uint8_t pin_number = first_pin->number + i; if (pin_number >= TOTAL_GPIO_COUNT) { mp_raise_ValueError(translate("Pin count too large")); } const mcu_pin_obj_t * pin = mcu_pin_global_dict_table[pin_number].value; if (exclusive_pin_use || _pin_reference_count[pin_number] == 0) { assert_pin_free(pin); } pins_we_use |= 1 << pin_number; } } return pins_we_use; } bool rp2pio_statemachine_construct(rp2pio_statemachine_obj_t *self, const uint16_t* program, size_t program_len, size_t frequency, const uint16_t* init, size_t init_len, const mcu_pin_obj_t * first_out_pin, uint8_t out_pin_count, const mcu_pin_obj_t * first_in_pin, uint8_t in_pin_count, const mcu_pin_obj_t * first_set_pin, uint8_t set_pin_count, const mcu_pin_obj_t * first_sideset_pin, uint8_t sideset_pin_count, uint32_t initial_pin_state, uint32_t initial_pin_direction, uint32_t pins_we_use, bool tx_fifo, bool rx_fifo, bool auto_pull, uint8_t pull_threshold, bool out_shift_right, bool wait_for_txstall, bool auto_push, uint8_t push_threshold, bool in_shift_right, bool claim_pins) { // Create a program id that isn't the pointer so we can store it without storing the original object. uint32_t program_id = ~((uint32_t) program); // Next, find a PIO and state machine to use. size_t pio_index = NUM_PIOS; uint8_t program_offset = 32; pio_program_t program_struct = { .instructions = (uint16_t*) program, .length = program_len, .origin = 0 }; for (size_t i = 0; i < NUM_PIOS; i++) { PIO pio = pio_instances[i]; uint8_t free_count = 0; for (size_t j = 0; j < NUM_PIO_STATE_MACHINES; j++) { if (_current_program_id[i][j] == program_id && _current_program_len[i][j] == program_len) { program_offset = _current_program_offset[i][j]; } int temp_claim = pio_claim_unused_sm(pio, false); if (temp_claim >= 0) { pio_sm_unclaim(pio, temp_claim); free_count++; } } if (free_count > 0 && (program_offset < 32 || pio_can_add_program(pio, &program_struct))) { pio_index = i; if (program_offset < 32) { break; } } // Reset program offset if we weren't able to find a free state machine // on that PIO. (We would have broken the loop otherwise.) program_offset = 32; } int state_machine = -1; if (pio_index < NUM_PIOS) { PIO pio = pio_instances[pio_index]; for (size_t i = 0; i < NUM_PIOS; i++) { if (i == pio_index) { continue; } if ((_current_pins[i] & pins_we_use) != 0) { // Pin in use by another PIO already. return false; } } state_machine = pio_claim_unused_sm(pio, false); } if (pio_index == NUM_PIOS || state_machine < 0 || state_machine >= NUM_PIO_STATE_MACHINES) { return false; } self->pio = pio_instances[pio_index]; self->state_machine = state_machine; if (program_offset == 32) { program_offset = pio_add_program(self->pio, &program_struct); } _current_program_id[pio_index][state_machine] = program_id; _current_program_len[pio_index][state_machine] = program_len; _current_program_offset[pio_index][state_machine] = program_offset; _current_sm_pins[pio_index][state_machine] = pins_we_use; _current_pins[pio_index] |= pins_we_use; pio_sm_set_pins_with_mask(self->pio, state_machine, initial_pin_state, pins_we_use); pio_sm_set_pindirs_with_mask(self->pio, state_machine, initial_pin_direction, pins_we_use); self->initial_pin_state = initial_pin_state; self->initial_pin_direction = initial_pin_direction; for (size_t pin_number = 0; pin_number < TOTAL_GPIO_COUNT; pin_number++) { if ((pins_we_use & (1 << pin_number)) == 0) { continue; } _pin_reference_count[pin_number]++; const mcu_pin_obj_t * pin = mcu_pin_global_dict_table[pin_number].value; // Also claim the pin at the top level when we're the first to grab it. if (_pin_reference_count[pin_number] == 1) { if (claim_pins) { claim_pin(pin); } pio_gpio_init(self->pio, pin_number); } } pio_sm_config c = {0, 0, 0}; if (frequency == 0) { frequency = clock_get_hz(clk_sys); } uint64_t frequency256 = ((uint64_t) clock_get_hz(clk_sys)) * 256; uint64_t div256 = frequency256 / frequency; if (frequency256 % div256 > 0) { div256 += 1; } self->actual_frequency = frequency256 / div256; sm_config_set_clkdiv_int_frac(&c, div256 / 256, div256 % 256); if (first_out_pin != NULL) { sm_config_set_out_pins(&c, first_out_pin->number, out_pin_count); } if (first_in_pin != NULL) { sm_config_set_in_pins(&c, first_in_pin->number); } if (first_set_pin != NULL) { sm_config_set_set_pins(&c, first_set_pin->number, set_pin_count); } if (first_sideset_pin != NULL) { sm_config_set_sideset(&c, sideset_pin_count, false /* optional */, false /* pin direction */); sm_config_set_sideset_pins(&c, first_sideset_pin->number); } sm_config_set_wrap(&c, program_offset, program_offset + program_len - 1); sm_config_set_in_shift(&c, in_shift_right, auto_push, push_threshold); sm_config_set_out_shift(&c, out_shift_right, auto_pull, pull_threshold); enum pio_fifo_join join = PIO_FIFO_JOIN_NONE; if (!rx_fifo) { join = PIO_FIFO_JOIN_TX; } else if (!tx_fifo) { join = PIO_FIFO_JOIN_RX; } if (rx_fifo) { self->rx_dreq = pio_get_dreq(self->pio, self->state_machine, false); } if (tx_fifo) { self->tx_dreq = pio_get_dreq(self->pio, self->state_machine, true); } self->in = rx_fifo; self->out = tx_fifo; self->out_shift_right = out_shift_right; self->in_shift_right = in_shift_right; self->wait_for_txstall = wait_for_txstall; self->init = init; self->init_len = init_len; sm_config_set_fifo_join(&c, join); pio_sm_init(self->pio, self->state_machine, program_offset, &c); common_hal_rp2pio_statemachine_run(self, init, init_len); common_hal_rp2pio_statemachine_set_frequency(self, frequency); pio_sm_set_enabled(self->pio, self->state_machine, true); return true; } static uint32_t mask_and_rotate(const mcu_pin_obj_t* first_pin, uint32_t bit_count, uint32_t value) { value = value & ((1 << bit_count) - 1); uint32_t shift = first_pin->number; return value << shift | value >> (32 - shift); } void common_hal_rp2pio_statemachine_construct(rp2pio_statemachine_obj_t *self, const uint16_t* program, size_t program_len, size_t frequency, const uint16_t* init, size_t init_len, const mcu_pin_obj_t * first_out_pin, uint8_t out_pin_count, uint32_t initial_out_pin_state, uint32_t initial_out_pin_direction, const mcu_pin_obj_t * first_in_pin, uint8_t in_pin_count, const mcu_pin_obj_t * first_set_pin, uint8_t set_pin_count, uint32_t initial_set_pin_state, uint32_t initial_set_pin_direction, const mcu_pin_obj_t * first_sideset_pin, uint8_t sideset_pin_count, uint32_t initial_sideset_pin_state, uint32_t initial_sideset_pin_direction, bool exclusive_pin_use, bool auto_pull, uint8_t pull_threshold, bool out_shift_right, bool wait_for_txstall, bool auto_push, uint8_t push_threshold, bool in_shift_right) { // First, check that all pins are free OR already in use by any PIO if exclusive_pin_use is false. uint32_t pins_we_use = 0; pins_we_use |= _check_pins_free(first_out_pin, out_pin_count, exclusive_pin_use); pins_we_use |= _check_pins_free(first_in_pin, in_pin_count, exclusive_pin_use); pins_we_use |= _check_pins_free(first_set_pin, set_pin_count, exclusive_pin_use); pins_we_use |= _check_pins_free(first_sideset_pin, sideset_pin_count, exclusive_pin_use); // Look through the program to see what we reference and make sure it was provided. bool tx_fifo = false; bool rx_fifo = false; bool in_loaded = false; // can be loaded in other ways besides the fifo bool out_loaded = false; bool in_used = false; bool out_used = false; for (size_t i = 0; i < program_len; i++) { uint16_t full_instruction = program[i]; uint16_t instruction = full_instruction & 0xe000; if (instruction == 0x8000) { if ((full_instruction & 0xe080) == pio_instr_bits_push) { rx_fifo = true; in_loaded = true; } else { // pull otherwise. tx_fifo = true; out_loaded = true; } } if (instruction == pio_instr_bits_jmp) { uint16_t condition = (full_instruction & 0x00e0) >> 5; if (condition == 0x6) { // GPIO mp_raise_NotImplementedError_varg(translate("Instruction %d jumps on pin"), i); } } if (instruction == pio_instr_bits_wait) { uint16_t wait_source = (full_instruction & 0x0060) >> 5; uint16_t wait_index = full_instruction & 0x001f; if (wait_source == 0 && (pins_we_use & (1 << wait_index)) == 0) { // GPIO mp_raise_ValueError_varg(translate("Instruction %d uses extra pin"), i); } if (wait_source == 1) { // Input pin if (first_in_pin == NULL) { mp_raise_ValueError_varg(translate("Missing first_in_pin. Instruction %d waits based on pin"), i); } if (wait_index > in_pin_count) { mp_raise_ValueError_varg(translate("Instruction %d waits on input outside of count"), i); } } } if (instruction == pio_instr_bits_in) { uint16_t source = (full_instruction & 0x00e0) >> 5; uint16_t bit_count = full_instruction & 0x001f; if (source == 0) { if (first_in_pin == NULL) { mp_raise_ValueError_varg(translate("Missing first_in_pin. Instruction %d shifts in from pin(s)"), i); } if (bit_count > in_pin_count) { mp_raise_ValueError_varg(translate("Instruction %d shifts in more bits than pin count"), i); } } if (auto_push) { in_loaded = true; rx_fifo = true; } in_used = true; } if (instruction == pio_instr_bits_out) { uint16_t bit_count = full_instruction & 0x001f; uint16_t destination = (full_instruction & 0x00e0) >> 5; // Check for pins or pindirs destination. if (destination == 0x0 || destination == 0x4) { if (first_out_pin == NULL) { mp_raise_ValueError_varg(translate("Missing first_out_pin. Instruction %d shifts out to pin(s)"), i); } if (bit_count > out_pin_count) { mp_raise_ValueError_varg(translate("Instruction %d shifts out more bits than pin count"), i); } } if (auto_pull) { out_loaded = true; tx_fifo = true; } out_used = true; } if (instruction == pio_instr_bits_set) { uint16_t destination = (full_instruction & 0x00e0) >> 5; // Check for pins or pindirs destination. if ((destination == 0x00 || destination == 0x4) && first_set_pin == NULL) { mp_raise_ValueError_varg(translate("Missing first_set_pin. Instruction %d sets pin(s)"), i); } } if (instruction == pio_instr_bits_mov) { uint16_t source = full_instruction & 0x0007; uint16_t destination = (full_instruction & 0x00e0) >> 5; // Check for pins or pindirs destination. if (destination == 0x0 && first_out_pin == NULL) { mp_raise_ValueError_varg(translate("Missing first_out_pin. Instruction %d writes pin(s)"), i); } if (source == 0x0 && first_in_pin == NULL) { mp_raise_ValueError_varg(translate("Missing first_in_pin. Instruction %d reads pin(s)"), i); } if (destination == 0x6) { in_loaded = true; } else if (destination == 0x7) { out_loaded = true; } } } if (!in_loaded && in_used) { mp_raise_ValueError_varg(translate("Program does IN without loading ISR")); } if (!out_loaded && out_used) { mp_raise_ValueError_varg(translate("Program does OUT without loading OSR")); } uint32_t initial_pin_state = mask_and_rotate(first_out_pin, out_pin_count, initial_out_pin_state); uint32_t initial_pin_direction = mask_and_rotate(first_out_pin, out_pin_count, initial_out_pin_direction); initial_set_pin_state = mask_and_rotate(first_set_pin, set_pin_count, initial_set_pin_state); initial_set_pin_direction = mask_and_rotate(first_set_pin, set_pin_count, initial_set_pin_direction); uint32_t set_out_overlap = mask_and_rotate(first_out_pin, out_pin_count, 0xffffffff) & mask_and_rotate(first_set_pin, set_pin_count, 0xffffffff); // Check that OUT and SET settings agree because we don't have a way of picking one over the other. if ((initial_pin_state & set_out_overlap) != (initial_set_pin_state & set_out_overlap)) { mp_raise_ValueError(translate("Initial set pin state conflicts with initial out pin state")); } if ((initial_pin_direction & set_out_overlap) != (initial_set_pin_direction & set_out_overlap)) { mp_raise_ValueError(translate("Initial set pin direction conflicts with initial out pin direction")); } initial_pin_state |= initial_set_pin_state; initial_pin_direction |= initial_set_pin_direction; // Sideset overrides OUT or SET so we always use its values. uint32_t sideset_mask = mask_and_rotate(first_sideset_pin, sideset_pin_count, 0x1f); initial_pin_state = (initial_pin_state & ~sideset_mask) | mask_and_rotate(first_sideset_pin, sideset_pin_count, initial_sideset_pin_state); initial_pin_direction = (initial_pin_direction & ~sideset_mask) | mask_and_rotate(first_sideset_pin, sideset_pin_count, initial_sideset_pin_direction); bool ok = rp2pio_statemachine_construct(self, program, program_len, frequency, init, init_len, first_out_pin, out_pin_count, first_in_pin, in_pin_count, first_set_pin, set_pin_count, first_sideset_pin, sideset_pin_count, initial_pin_state, initial_pin_direction, pins_we_use, tx_fifo, rx_fifo, auto_pull, pull_threshold, out_shift_right, wait_for_txstall, auto_push, push_threshold, in_shift_right, true /* claim pins */); if (!ok) { mp_raise_RuntimeError(translate("All state machines in use")); } } void common_hal_rp2pio_statemachine_restart(rp2pio_statemachine_obj_t *self) { pio_sm_restart(self->pio, self->state_machine); uint8_t pio_index = pio_get_index(self->pio); uint32_t pins_we_use = _current_sm_pins[pio_index][self->state_machine]; pio_sm_set_pins_with_mask(self->pio, self->state_machine, self->initial_pin_state, pins_we_use); pio_sm_set_pindirs_with_mask(self->pio, self->state_machine, self->initial_pin_direction, pins_we_use); common_hal_rp2pio_statemachine_run(self, self->init, self->init_len); pio_sm_set_enabled(self->pio, self->state_machine, true); } void common_hal_rp2pio_statemachine_stop(rp2pio_statemachine_obj_t *self) { pio_sm_set_enabled(self->pio, self->state_machine, false); } void common_hal_rp2pio_statemachine_run(rp2pio_statemachine_obj_t *self, const uint16_t *instructions, size_t len) { for (size_t i = 0; i < len; i++) { pio_sm_exec(self->pio, self->state_machine, instructions[i]); } } uint32_t common_hal_rp2pio_statemachine_get_frequency(rp2pio_statemachine_obj_t* self) { return self->actual_frequency; } void common_hal_rp2pio_statemachine_set_frequency(rp2pio_statemachine_obj_t* self, uint32_t frequency) { if (frequency == 0) { frequency = clock_get_hz(clk_sys); } uint64_t frequency256 = ((uint64_t) clock_get_hz(clk_sys)) * 256; uint64_t div256 = frequency256 / frequency; if (frequency256 % div256 > 0) { div256 += 1; } // 0 is interpreted as 0x10000 so it's valid. if (div256 / 256 > 0x10000 || frequency > clock_get_hz(clk_sys)) { mp_raise_ValueError_varg(translate("%q out of range"), MP_QSTR_frequency); } self->actual_frequency = frequency256 / div256; pio_sm_set_clkdiv_int_frac(self->pio, self->state_machine, div256 / 256, div256 % 256); // Reset the clkdiv counter in case our new TOP is lower. pio_sm_clkdiv_restart(self->pio, self->state_machine); } void rp2pio_statemachine_deinit(rp2pio_statemachine_obj_t *self, bool leave_pins) { uint8_t sm = self->state_machine; uint8_t pio_index = pio_get_index(self->pio); _never_reset[pio_index][sm] = false; _reset_statemachine(self->pio, sm, leave_pins); self->state_machine = NUM_PIO_STATE_MACHINES; } void common_hal_rp2pio_statemachine_deinit(rp2pio_statemachine_obj_t *self) { rp2pio_statemachine_deinit(self, false); } void common_hal_rp2pio_statemachine_never_reset(rp2pio_statemachine_obj_t *self) { uint8_t sm = self->state_machine; uint8_t pio_index = pio_get_index(self->pio); _never_reset[pio_index][sm] = true; // TODO: never reset all the pins } bool common_hal_rp2pio_statemachine_deinited(rp2pio_statemachine_obj_t *self) { return self->state_machine == NUM_PIO_STATE_MACHINES; } enum dma_channel_transfer_size _stride_to_dma_size(uint8_t stride) { switch (stride) { case 4: return DMA_SIZE_32; case 2: return DMA_SIZE_16; case 1: default: return DMA_SIZE_8; } } static bool _transfer(rp2pio_statemachine_obj_t *self, const uint8_t *data_out, size_t out_len, uint8_t out_stride_in_bytes, uint8_t *data_in, size_t in_len, uint8_t in_stride_in_bytes) { // This implementation is based on SPI but varies because the tx and rx buffers // may be different lengths and occur at different times or speeds. // Use DMA for large transfers if channels are available const size_t dma_min_size_threshold = 32; int chan_tx = -1; int chan_rx = -1; size_t len = MAX(out_len, in_len); bool tx = data_out != NULL; bool rx = data_in != NULL; if (len >= dma_min_size_threshold) { // Use DMA channels to service the two FIFOs if (tx) { chan_tx = dma_claim_unused_channel(false); } if (rx) { chan_rx = dma_claim_unused_channel(false); } } volatile uint8_t* tx_destination = NULL; const volatile uint8_t* rx_source = NULL; if (tx) { tx_destination = (volatile uint8_t*) &self->pio->txf[self->state_machine]; if (!self->out_shift_right) { tx_destination += 4 - out_stride_in_bytes; } } if (rx) { rx_source = (const volatile uint8_t*) &self->pio->rxf[self->state_machine]; if (self->in_shift_right) { rx_source += 4 - in_stride_in_bytes; } } uint32_t stall_mask = 1 << (PIO_FDEBUG_TXSTALL_LSB + self->state_machine); bool use_dma = (!rx || chan_rx >= 0) && (!tx || chan_tx >= 0); if (use_dma) { dma_channel_config c; uint32_t channel_mask = 0; if (tx) { c = dma_channel_get_default_config(chan_tx); channel_config_set_transfer_data_size(&c, _stride_to_dma_size(out_stride_in_bytes)); channel_config_set_dreq(&c, self->tx_dreq); channel_config_set_read_increment(&c, true); channel_config_set_write_increment(&c, false); dma_channel_configure(chan_tx, &c, tx_destination, data_out, out_len / out_stride_in_bytes, false); channel_mask |= 1u << chan_tx; } if (rx) { c = dma_channel_get_default_config(chan_rx); channel_config_set_transfer_data_size(&c, _stride_to_dma_size(in_stride_in_bytes)); channel_config_set_dreq(&c, self->rx_dreq); channel_config_set_read_increment(&c, false); channel_config_set_write_increment(&c, true); dma_channel_configure(chan_rx, &c, data_in, rx_source, in_len / in_stride_in_bytes, false); channel_mask |= 1u << chan_rx; } dma_start_channel_mask(channel_mask); while ((rx && dma_channel_is_busy(chan_rx)) || (tx && dma_channel_is_busy(chan_tx))) { // TODO: We should idle here until we get a DMA interrupt or something else. RUN_BACKGROUND_TASKS; if (mp_hal_is_interrupted()) { if (rx && dma_channel_is_busy(chan_rx)) { dma_channel_abort(chan_rx); } if (tx && dma_channel_is_busy(chan_tx)) { dma_channel_abort(chan_tx); } break; } } // Clear the stall bit so we can detect when the state machine is done transmitting. self->pio->fdebug = stall_mask; } // If we have claimed only one channel successfully, we should release immediately. This also // releases the DMA after use_dma has been done. if (chan_rx >= 0) { dma_channel_unclaim(chan_rx); } if (chan_tx >= 0) { dma_channel_unclaim(chan_tx); } if (!use_dma && !mp_hal_is_interrupted()) { // Use software for small transfers, or if couldn't claim two DMA channels size_t rx_remaining = in_len / in_stride_in_bytes; size_t tx_remaining = out_len / out_stride_in_bytes; while (rx_remaining || tx_remaining) { while (tx_remaining && !pio_sm_is_tx_fifo_full(self->pio, self->state_machine)) { if (out_stride_in_bytes == 1) { *tx_destination = *data_out; } else if (out_stride_in_bytes == 2) { *((uint16_t*) tx_destination) = *((uint16_t*) data_out); } else if (out_stride_in_bytes == 4) { *((uint32_t*) tx_destination) = *((uint32_t*) data_out); } data_out += out_stride_in_bytes; --tx_remaining; } while (rx_remaining && !pio_sm_is_rx_fifo_empty(self->pio, self->state_machine)) { if (in_stride_in_bytes == 1) { *data_in = (uint8_t) *rx_source; } else if (in_stride_in_bytes == 2) { *((uint16_t*) data_in) = *((uint16_t*) rx_source); } else if (in_stride_in_bytes == 4) { *((uint32_t*) data_in) = *((uint32_t*) rx_source); } data_in += in_stride_in_bytes; --rx_remaining; } RUN_BACKGROUND_TASKS; if (mp_hal_is_interrupted()) { break; } } // Clear the stall bit so we can detect when the state machine is done transmitting. self->pio->fdebug = stall_mask; } // Wait for the state machine to finish transmitting the data we've queued // up. if (tx) { while (!pio_sm_is_tx_fifo_empty(self->pio, self->state_machine) || (self->wait_for_txstall && (self->pio->fdebug & stall_mask) == 0)) { RUN_BACKGROUND_TASKS; } } return true; } // TODO: Provide a way around these checks in case someone wants to use the FIFO // with manually run code. bool common_hal_rp2pio_statemachine_write(rp2pio_statemachine_obj_t *self, const uint8_t *data, size_t len, uint8_t stride_in_bytes) { if (!self->out) { mp_raise_RuntimeError(translate("No out in program")); } return _transfer(self, data, len, stride_in_bytes, NULL, 0, 0); } bool common_hal_rp2pio_statemachine_readinto(rp2pio_statemachine_obj_t *self, uint8_t *data, size_t len, uint8_t stride_in_bytes) { if (!self->in) { mp_raise_RuntimeError(translate("No in in program")); } return _transfer(self, NULL, 0, 0, data, len, stride_in_bytes); } bool common_hal_rp2pio_statemachine_write_readinto(rp2pio_statemachine_obj_t *self, const uint8_t *data_out, size_t out_len, uint8_t out_stride_in_bytes, uint8_t *data_in, size_t in_len, uint8_t in_stride_in_bytes) { if (!self->in || !self->out) { mp_raise_RuntimeError(translate("No in or out in program")); } return _transfer(self, data_out, out_len, out_stride_in_bytes, data_in, in_len, in_stride_in_bytes); } bool common_hal_rp2pio_statemachine_get_rxstall(rp2pio_statemachine_obj_t* self) { uint32_t stall_mask = 1 << (PIO_FDEBUG_RXSTALL_LSB + self->state_machine); return (self->pio->fdebug & stall_mask) != 0; } void common_hal_rp2pio_statemachine_clear_rxfifo(rp2pio_statemachine_obj_t *self) { uint8_t level = pio_sm_get_rx_fifo_level(self->pio, self->state_machine); uint32_t stall_mask = 1 << (PIO_FDEBUG_RXSTALL_LSB + self->state_machine); for (size_t i = 0; i < level; i++) { (void) self->pio->rxf[self->state_machine]; } self->pio->fdebug = stall_mask; }