djsundog/circuitpython
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
5bb722b927
circuitpython/ports/raspberrypi/common-hal/rp2pio/StateMachine.c
Scott Shawcroft 6a6f22b0e6
pre-commit
2021-01-20 23:30:15 -08:00

586 lines
22 KiB
C
Raw Blame History

/*
* 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);
pio_sm_unclaim(pio, 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 < 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;
}
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 pins_we_use, bool tx_fifo, bool rx_fifo,
bool auto_pull, uint8_t pull_threshold, bool out_shift_right,
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;
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;
sm_config_set_fifo_join(&c, join);
pio_sm_init(self->pio, self->state_machine, program_offset, &c);
pio_sm_set_enabled(self->pio, self->state_machine, true);
for (size_t i = 0; i < init_len; i++) {
pio_sm_exec(self->pio, self->state_machine, init[i]);
}
return true;
}
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,
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,
bool exclusive_pin_use,
bool auto_pull, uint8_t pull_threshold, bool out_shift_right,
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"));
}
if (in_pin_count > 8 || out_pin_count > 8) {
mp_raise_NotImplementedError(translate("Only IN/OUT of up to 8 supported"));
}
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,
pins_we_use, tx_fifo, rx_fifo,
auto_pull, pull_threshold, out_shift_right,
auto_push, push_threshold, in_shift_right,
true /* claim pins */);
if (!ok) {
mp_raise_RuntimeError(translate("All state machines in use"));
}
}
uint32_t common_hal_rp2pio_statemachine_get_frequency(rp2pio_statemachine_obj_t* self) {
return self->actual_frequency;
}
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;
}
static bool _transfer(rp2pio_statemachine_obj_t *self,
const uint8_t *data_out, size_t out_len,
uint8_t *data_in, size_t in_len) {
// 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 += 3;
}
}
if (rx) {
rx_source = (const volatile uint8_t*) &self->pio->rxf[self->state_machine];
if (!self->in_shift_right) {
rx_source += 3;
}
}
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, DMA_SIZE_8);
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,
len,
false);
channel_mask |= 1u << chan_tx;
}
if (rx) {
c = dma_channel_get_default_config(chan_rx);
channel_config_set_transfer_data_size(&c, DMA_SIZE_8);
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,
len,
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 = PIO_FDEBUG_TXSTALL_BITS;
}
// 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;
size_t tx_remaining = out_len;
while (rx_remaining || tx_remaining) {
if (tx_remaining && !pio_sm_is_tx_fifo_full(self->pio, self->state_machine)) {
*tx_destination = *data_out;
data_out++;
--tx_remaining;
}
if (rx_remaining && !pio_sm_is_rx_fifo_empty(self->pio, self->state_machine)) {
*data_in = (uint8_t) *rx_source;
data_in++;
--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 = PIO_FDEBUG_TXSTALL_BITS;
}
// 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->pio->fdebug & PIO_FDEBUG_TXSTALL_BITS) == 0) {
RUN_BACKGROUND_TASKS;
}
}
return true;
}
// Writes out the given data.
bool common_hal_rp2pio_statemachine_write(rp2pio_statemachine_obj_t *self,
const uint8_t *data, size_t len) {
if (!self->out) {
mp_raise_RuntimeError(translate("No out in program"));
}
return _transfer(self, data, len, NULL, 0);
}
Reference in New Issue View Git Blame Copy Permalink