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circuitpython/ports/raspberrypi/common-hal/rp2pio/StateMachine.c

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/*
* 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 <string.h>
#include "bindings/rp2pio/StateMachine.h"
#include "common-hal/microcontroller/__init__.h"
#include "shared-bindings/digitalio/Pull.h"
#include "shared-bindings/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 "src/rp2_common/hardware_irq/include/hardware/irq.h"
#include "shared/runtime/interrupt_char.h"
#include "py/obj.h"
#include "py/objproperty.h"
#include "py/runtime.h"
#define NO_DMA_CHANNEL (-1)
// Count how many state machines are using each pin.
STATIC uint8_t _pin_reference_count[NUM_BANK0_GPIOS];
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 int8_t _sm_dma_plus_one[NUM_PIOS][NUM_PIO_STATE_MACHINES];
#define SM_DMA_ALLOCATED(pio_index, sm) (_sm_dma_plus_one[(pio_index)][(sm)] != 0)
#define SM_DMA_GET_CHANNEL(pio_index, sm) (_sm_dma_plus_one[(pio_index)][(sm)] - 1)
#define SM_DMA_CLEAR_CHANNEL(pio_index, sm) (_sm_dma_plus_one[(pio_index)][(sm)] = 0)
#define SM_DMA_SET_CHANNEL(pio_isntance, sm, channel) (_sm_dma_plus_one[(pio_index)][(sm)] = (channel) + 1)
STATIC PIO pio_instances[2] = {pio0, pio1};
typedef void (*interrupt_handler_type)(void *);
STATIC interrupt_handler_type _interrupt_handler[NUM_PIOS][NUM_PIO_STATE_MACHINES];
STATIC void *_interrupt_arg[NUM_PIOS][NUM_PIO_STATE_MACHINES];
STATIC void rp2pio_statemachine_interrupt_handler(void);
static void rp2pio_statemachine_set_pull(uint32_t pull_pin_up, uint32_t pull_pin_down, uint32_t pins_we_use) {
for (size_t i = 0; i < NUM_BANK0_GPIOS; i++) {
bool used = pins_we_use & (1 << i);
if (used) {
bool pull_up = pull_pin_up & (1 << i);
bool pull_down = pull_pin_down & (1 << i);
gpio_set_pulls(i, pull_up, pull_down);
}
}
}
STATIC void rp2pio_statemachine_clear_dma(int pio_index, int sm) {
if (SM_DMA_ALLOCATED(pio_index, sm)) {
int channel = SM_DMA_GET_CHANNEL(pio_index, sm);
uint32_t channel_mask = 1u << channel;
dma_hw->inte0 &= ~channel_mask;
if (!dma_hw->inte0) {
irq_set_mask_enabled(1 << DMA_IRQ_0, false);
}
MP_STATE_PORT(background_pio)[channel] = NULL;
dma_channel_abort(channel);
dma_channel_unclaim(channel);
}
SM_DMA_CLEAR_CHANNEL(pio_index, sm);
}
STATIC void _reset_statemachine(PIO pio, uint8_t sm, bool leave_pins) {
uint8_t pio_index = pio_get_index(pio);
rp2pio_statemachine_clear_dma(pio_index, sm);
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 < NUM_BANK0_GPIOS; 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->inte0 &= ~((PIO_IRQ0_INTF_SM0_RXNEMPTY_BITS | PIO_IRQ0_INTF_SM0_TXNFULL_BITS | PIO_IRQ0_INTF_SM0_BITS) << sm);
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);
}
}
for (uint8_t irq = PIO0_IRQ_0; irq <= PIO1_IRQ_1; irq++) {
irq_handler_t int_handler = irq_get_exclusive_handler(irq);
if (int_handler > 0) {
irq_set_enabled(irq, false);
irq_remove_handler(irq,int_handler);
}
}
}
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 >= NUM_BANK0_GPIOS) {
mp_raise_ValueError(translate("Pin count too large"));
}
const mcu_pin_obj_t *pin = mcu_get_pin_by_number(pin_number);
if (!pin) {
mp_raise_ValueError_varg(translate("%q in use"), MP_QSTR_Pin);
}
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,
uint32_t pull_pin_up, uint32_t pull_pin_down,
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,
const mcu_pin_obj_t *jmp_pin,
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,
bool user_interruptible,
bool sideset_enable,
int wrap_target, int wrap
) {
// 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 = -1
};
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;
}
size_t state_machine = NUM_PIO_STATE_MACHINES;
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);
}
self->offset = program_offset;
_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);
rp2pio_statemachine_set_pull(pull_pin_up, pull_pin_down, pins_we_use);
self->initial_pin_state = initial_pin_state;
self->initial_pin_direction = initial_pin_direction;
self->pull_pin_up = pull_pin_up;
self->pull_pin_down = pull_pin_down;
for (size_t pin_number = 0; pin_number < NUM_BANK0_GPIOS; pin_number++) {
if ((pins_we_use & (1 << pin_number)) == 0) {
continue;
}
const mcu_pin_obj_t *pin = mcu_get_pin_by_number(pin_number);
if (!pin) {
return false;
}
_pin_reference_count[pin_number]++;
// 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);
}
// Use lowest drive level for all State Machine outputs. (#7515
// workaround). Remove if/when Pin objects get a drive_strength
// property and use that value instead.
gpio_set_drive_strength(pin_number, GPIO_DRIVE_STRENGTH_2MA);
}
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) {
size_t total_sideset_bits = sideset_pin_count;
if (sideset_enable) {
total_sideset_bits += 1;
}
sm_config_set_sideset(&c, total_sideset_bits, sideset_enable, false /* pin direction */);
sm_config_set_sideset_pins(&c, first_sideset_pin->number);
}
if (jmp_pin != NULL) {
sm_config_set_jmp_pin(&c, jmp_pin->number);
}
mp_arg_validate_int_range(wrap, -1, program_len - 1, MP_QSTR_wrap);
if (wrap == -1) {
wrap = program_len - 1;
}
mp_arg_validate_int_range(wrap_target, 0, program_len - 1, MP_QSTR_wrap_target);
wrap += program_offset;
wrap_target += program_offset;
sm_config_set_wrap(&c, wrap_target, wrap);
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->user_interruptible = user_interruptible;
self->init = init;
self->init_len = init_len;
sm_config_set_fifo_join(&c, join);
self->sm_config = c;
// no DMA allocated
SM_DMA_CLEAR_CHANNEL(pio_index, state_machine);
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) {
if (!first_pin) {
return 0;
}
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,
uint32_t pull_pin_up, uint32_t pull_pin_down,
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 sideset_enable,
const mcu_pin_obj_t *jmp_pin, digitalio_pull_t jmp_pull,
uint32_t wait_gpio_mask,
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,
bool user_interruptible,
int wrap_target, int wrap) {
// 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 = wait_gpio_mask;
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);
pins_we_use |= _check_pins_free(jmp_pin, 1, 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) && (jmp_pin == NULL)) {
mp_raise_ValueError_varg(translate("Missing jmp_pin. 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);
// Deal with pull up/downs
uint32_t pull_up = mask_and_rotate(first_in_pin, in_pin_count, pull_pin_up);
uint32_t pull_down = mask_and_rotate(first_in_pin, in_pin_count, pull_pin_down);
if (jmp_pin) {
uint32_t jmp_mask = mask_and_rotate(jmp_pin, 1, 0x1f);
if (jmp_pull == PULL_UP) {
pull_up |= jmp_mask;
}
if (jmp_pull == PULL_DOWN) {
pull_up |= jmp_mask;
}
}
if (initial_pin_direction & (pull_up | pull_down)) {
mp_raise_ValueError(translate("pull masks conflict with direction masks"));
}
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,
pull_up, pull_down,
first_set_pin, set_pin_count,
first_sideset_pin, sideset_pin_count,
initial_pin_state, initial_pin_direction,
jmp_pin,
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 */,
user_interruptible,
sideset_enable,
wrap_target, wrap);
if (!ok) {
mp_raise_RuntimeError(translate("All state machines in use"));
}
}
void common_hal_rp2pio_statemachine_restart(rp2pio_statemachine_obj_t *self) {
common_hal_rp2pio_statemachine_stop(self);
// Reset program counter to the original offset. A JMP is 0x0000 plus
// the desired offset, so we can just use self->offset.
pio_sm_exec(self->pio, self->state_machine, self->offset);
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);
rp2pio_statemachine_set_pull(self->pull_pin_up, self->pull_pin_down, 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) {
common_hal_rp2pio_statemachine_stop(self);
(void)common_hal_rp2pio_statemachine_stop_background_write(self);
uint8_t sm = self->state_machine;
uint8_t pio_index = pio_get_index(self->pio);
common_hal_mcu_disable_interrupts();
_interrupt_arg[pio_index][sm] = NULL;
_interrupt_handler[pio_index][sm] = NULL;
common_hal_mcu_enable_interrupts();
_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;
}
STATIC 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, bool swap_out, bool swap_in) {
// 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;
bool use_dma = len >= dma_min_size_threshold || swap_out || swap_in;
if (use_dma) {
// Use DMA channels to service the two FIFOs
if (tx) {
chan_tx = dma_claim_unused_channel(false);
// DMA allocation failed...
if (chan_tx < 0) {
return false;
}
}
if (rx) {
chan_rx = dma_claim_unused_channel(false);
// DMA allocation failed...
if (chan_rx < 0) {
// may need to free tx channel
if (chan_tx >= 0) {
dma_channel_unclaim(chan_tx);
}
return 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);
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);
channel_config_set_bswap(&c, swap_out);
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);
channel_config_set_bswap(&c, swap_in);
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 (self->user_interruptible && 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 && !(self->user_interruptible && 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 (self->user_interruptible && 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;
if (self->user_interruptible && mp_hal_is_interrupted()) {
break;
}
}
}
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, bool swap) {
if (!self->out) {
mp_raise_RuntimeError(translate("No out in program"));
}
return _transfer(self, data, len, stride_in_bytes, NULL, 0, 0, swap, false);
}
bool common_hal_rp2pio_statemachine_readinto(rp2pio_statemachine_obj_t *self, uint8_t *data, size_t len, uint8_t stride_in_bytes, bool swap) {
if (!self->in) {
mp_raise_RuntimeError(translate("No in in program"));
}
return _transfer(self, NULL, 0, 0, data, len, stride_in_bytes, false, swap);
}
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, bool swap_out, bool swap_in) {
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, swap_out, swap_in);
}
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;
}
bool common_hal_rp2pio_statemachine_get_txstall(rp2pio_statemachine_obj_t *self) {
uint32_t stall_mask = 1 << (PIO_FDEBUG_TXSTALL_LSB + self->state_machine);
return (self->pio->fdebug & stall_mask) != 0;
}
void common_hal_rp2pio_statemachine_clear_txstall(rp2pio_statemachine_obj_t *self) {
(void)pio_sm_get_rx_fifo_level(self->pio, self->state_machine);
uint32_t stall_mask = 1 << (PIO_FDEBUG_TXSTALL_LSB + self->state_machine);
self->pio->fdebug = stall_mask;
}
size_t common_hal_rp2pio_statemachine_get_in_waiting(rp2pio_statemachine_obj_t *self) {
uint8_t level = pio_sm_get_rx_fifo_level(self->pio, self->state_machine);
return level;
}
void common_hal_rp2pio_statemachine_set_interrupt_handler(rp2pio_statemachine_obj_t *self, void (*handler)(void *), void *arg, int mask) {
uint8_t pio_index = pio_get_index(self->pio);
uint8_t sm = self->state_machine;
common_hal_mcu_disable_interrupts();
uint32_t inte = self->pio->inte0;
inte &= ~((PIO_IRQ0_INTF_SM0_RXNEMPTY_BITS | PIO_IRQ0_INTF_SM0_TXNFULL_BITS | PIO_IRQ0_INTF_SM0_BITS) << sm);
inte |= (mask << sm);
self->pio->inte0 = inte;
_interrupt_arg[pio_index][sm] = arg;
_interrupt_handler[pio_index][sm] = handler;
irq_set_exclusive_handler(PIO0_IRQ_0 + 2 * pio_index, rp2pio_statemachine_interrupt_handler);
irq_set_enabled(PIO0_IRQ_0 + 2 * pio_index, true);
common_hal_mcu_enable_interrupts();
}
STATIC void rp2pio_statemachine_interrupt_handler(void) {
for (size_t pio_index = 0; pio_index < NUM_PIOS; pio_index++) {
PIO pio = pio_instances[pio_index];
for (size_t sm = 0; sm < NUM_PIO_STATE_MACHINES; sm++) {
if (!_interrupt_handler[pio_index][sm]) {
continue;
}
uint32_t intf = (PIO_IRQ0_INTF_SM0_RXNEMPTY_BITS | PIO_IRQ0_INTF_SM0_TXNFULL_BITS | PIO_IRQ0_INTF_SM0_BITS) << sm;
if (pio->ints0 & intf) {
_interrupt_handler[pio_index][sm](_interrupt_arg[pio_index][sm]);
}
}
}
}
uint8_t rp2pio_statemachine_program_offset(rp2pio_statemachine_obj_t *self) {
uint8_t pio_index = pio_get_index(self->pio);
uint8_t sm = self->state_machine;
return _current_program_offset[pio_index][sm];
}
bool common_hal_rp2pio_statemachine_background_write(rp2pio_statemachine_obj_t *self, const sm_buf_info *once, const sm_buf_info *loop, uint8_t stride_in_bytes, bool swap) {
uint8_t pio_index = pio_get_index(self->pio);
uint8_t sm = self->state_machine;
int pending_buffers = (once->info.len != 0) + (loop->info.len != 0);
if (!once->info.len) {
once = loop;
}
if (SM_DMA_ALLOCATED(pio_index, sm)) {
if (stride_in_bytes != self->background_stride_in_bytes) {
mp_raise_ValueError(translate("Mismatched data size"));
}
if (swap != self->byteswap) {
mp_raise_ValueError(translate("Mismatched swap flag"));
}
while (self->pending_buffers) {
RUN_BACKGROUND_TASKS;
if (self->user_interruptible && mp_hal_is_interrupted()) {
return false;
}
}
common_hal_mcu_disable_interrupts();
self->once = *once;
self->loop = *loop;
self->pending_buffers = pending_buffers;
if (self->dma_completed && self->once.info.len) {
rp2pio_statemachine_dma_complete(self, SM_DMA_GET_CHANNEL(pio_index, sm));
self->dma_completed = false;
}
common_hal_mcu_enable_interrupts();
return true;
}
int channel = dma_claim_unused_channel(false);
if (channel == -1) {
return false;
}
SM_DMA_SET_CHANNEL(pio_index, sm, channel);
volatile uint8_t *tx_destination = (volatile uint8_t *)&self->pio->txf[self->state_machine];
self->tx_dreq = pio_get_dreq(self->pio, self->state_machine, true);
dma_channel_config c;
self->current = *once;
self->once = *loop;
self->loop = *loop;
self->pending_buffers = pending_buffers;
self->dma_completed = false;
self->background_stride_in_bytes = stride_in_bytes;
self->byteswap = swap;
c = dma_channel_get_default_config(channel);
channel_config_set_transfer_data_size(&c, _stride_to_dma_size(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);
channel_config_set_bswap(&c, swap);
dma_channel_configure(channel, &c,
tx_destination,
once->info.buf,
once->info.len / stride_in_bytes,
false);
common_hal_mcu_disable_interrupts();
MP_STATE_PORT(background_pio)[channel] = self;
dma_hw->inte0 |= 1u << channel;
irq_set_mask_enabled(1 << DMA_IRQ_0, true);
dma_start_channel_mask(1u << channel);
common_hal_mcu_enable_interrupts();
return true;
}
void rp2pio_statemachine_dma_complete(rp2pio_statemachine_obj_t *self, int channel) {
self->current = self->once;
self->once = self->loop;
if (self->current.info.buf) {
if (self->pending_buffers > 0) {
self->pending_buffers--;
}
dma_channel_set_read_addr(channel, self->current.info.buf, false);
dma_channel_set_trans_count(channel, self->current.info.len / self->background_stride_in_bytes, true);
} else {
self->dma_completed = true;
self->pending_buffers = 0; // should be a no-op
}
}
bool common_hal_rp2pio_statemachine_stop_background_write(rp2pio_statemachine_obj_t *self) {
uint8_t pio_index = pio_get_index(self->pio);
uint8_t sm = self->state_machine;
rp2pio_statemachine_clear_dma(pio_index, sm);
memset(&self->current, 0, sizeof(self->current));
memset(&self->once, 0, sizeof(self->once));
memset(&self->loop, 0, sizeof(self->loop));
self->pending_buffers = 0;
return true;
}
bool common_hal_rp2pio_statemachine_get_writing(rp2pio_statemachine_obj_t *self) {
return !self->dma_completed;
}
int common_hal_rp2pio_statemachine_get_pending(rp2pio_statemachine_obj_t *self) {
return self->pending_buffers;
}
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