circuitpython/ports/samd/mphalport.c
robert-hh e33db80a59 samd/clock_config: Extend the SAMD51 us-counter to 60 bit.
This removes the difference in the time.ticks_us() range between SAMD21 and
SAMD51.

The function mp_hal_ticks_us_64() is added and used for:
- SAMD51's mp_hal_ticks_us and mp_hal_delay_us().
  For SAMD21, keep the previous methods, which are faster.
- mp_hal_ticks_ms() and mp_hal_tick_ms_64(), which saves some bytes
  and removes a potential race condition every 50 days.

Also set the us-counter for SAMD51 to 16 MHz for a faster reading of the
microsecond value.

Note: With SAMD51, mp_hal_ticks_us_64() has a 60 bit range only, which is
still a long time (~36000 years).
2022-10-25 23:26:14 +11:00

209 lines
6.4 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2019 Damien P. George
* Copyright (c) 2022 Robert Hammelrath
*
* 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 "py/runtime.h"
#include "py/mphal.h"
#include "py/stream.h"
#include "shared/runtime/interrupt_char.h"
#include "extmod/misc.h"
#include "samd_soc.h"
#include "tusb.h"
#ifndef MICROPY_HW_STDIN_BUFFER_LEN
#define MICROPY_HW_STDIN_BUFFER_LEN 128
#endif
extern volatile uint32_t ticks_us64_upper;
STATIC uint8_t stdin_ringbuf_array[MICROPY_HW_STDIN_BUFFER_LEN];
ringbuf_t stdin_ringbuf = { stdin_ringbuf_array, sizeof(stdin_ringbuf_array), 0, 0 };
uint8_t cdc_itf_pending; // keep track of cdc interfaces which need attention to poll
void poll_cdc_interfaces(void) {
// any CDC interfaces left to poll?
if (cdc_itf_pending && ringbuf_free(&stdin_ringbuf)) {
for (uint8_t itf = 0; itf < 8; ++itf) {
if (cdc_itf_pending & (1 << itf)) {
tud_cdc_rx_cb(itf);
if (!cdc_itf_pending) {
break;
}
}
}
}
}
void tud_cdc_rx_cb(uint8_t itf) {
// consume pending USB data immediately to free usb buffer and keep the endpoint from stalling.
// in case the ringbuffer is full, mark the CDC interface that need attention later on for polling
cdc_itf_pending &= ~(1 << itf);
for (uint32_t bytes_avail = tud_cdc_n_available(itf); bytes_avail > 0; --bytes_avail) {
if (ringbuf_free(&stdin_ringbuf)) {
int data_char = tud_cdc_read_char();
#if MICROPY_KBD_EXCEPTION
if (data_char == mp_interrupt_char) {
// Clear the ring buffer
stdin_ringbuf.iget = stdin_ringbuf.iput = 0;
// and stop
mp_sched_keyboard_interrupt();
} else {
ringbuf_put(&stdin_ringbuf, data_char);
}
#else
ringbuf_put(&stdin_ringbuf, data_char);
#endif
} else {
cdc_itf_pending |= (1 << itf);
return;
}
}
}
void mp_hal_set_pin_mux(mp_hal_pin_obj_t pin, uint8_t mux) {
int pin_grp = pin / 32;
int port_grp = (pin % 32) / 2;
PORT->Group[pin_grp].PINCFG[pin % 32].bit.PMUXEN = 1; // Enable Mux
if (pin & 1) {
PORT->Group[pin_grp].PMUX[port_grp].bit.PMUXO = mux;
} else {
PORT->Group[pin_grp].PMUX[port_grp].bit.PMUXE = mux;
}
}
void mp_hal_clr_pin_mux(mp_hal_pin_obj_t pin) {
int pin_grp = pin / 32;
PORT->Group[pin_grp].PINCFG[pin % 32].bit.PMUXEN = 0; // Disable Mux
}
void mp_hal_delay_ms(mp_uint_t ms) {
if (ms > 10) {
uint32_t t0 = systick_ms;
while (systick_ms - t0 < ms) {
MICROPY_EVENT_POLL_HOOK
}
} else {
mp_hal_delay_us(ms * 1000);
}
}
void mp_hal_delay_us(mp_uint_t us) {
if (us > 0) {
#if defined(MCU_SAMD21)
uint32_t start = mp_hal_ticks_us();
while ((mp_hal_ticks_us() - start) < us) {
}
#else
uint64_t stop = mp_hal_ticks_us_64() + us;
while (mp_hal_ticks_us_64() < stop) {
}
#endif
}
}
uint64_t mp_hal_ticks_us_64(void) {
uint32_t us64_upper = ticks_us64_upper;
uint32_t us64_lower;
uint8_t intflag;
__disable_irq();
#if defined(MCU_SAMD21)
us64_lower = REG_TC4_COUNT32_COUNT;
intflag = TC4->COUNT32.INTFLAG.reg;
#elif defined(MCU_SAMD51)
TC0->COUNT32.CTRLBSET.reg = TC_CTRLBSET_CMD_READSYNC;
while (TC0->COUNT32.CTRLBSET.reg != 0) {
}
us64_lower = REG_TC0_COUNT32_COUNT;
intflag = TC0->COUNT32.INTFLAG.reg;
#endif
__enable_irq();
if ((intflag & TC_INTFLAG_OVF) && us64_lower < 0x10000000) {
// The timer counter overflowed before reading it but the IRQ handler
// has not yet been called, so perform the IRQ arithmetic now.
us64_upper++;
}
#if defined(MCU_SAMD21)
return ((uint64_t)us64_upper << 32) | us64_lower;
#elif defined(MCU_SAMD51)
return ((uint64_t)us64_upper << 28) | (us64_lower >> 4);
#endif
}
uintptr_t mp_hal_stdio_poll(uintptr_t poll_flags) {
uintptr_t ret = 0;
poll_cdc_interfaces();
if ((poll_flags & MP_STREAM_POLL_RD) && ringbuf_peek(&stdin_ringbuf) != -1) {
ret |= MP_STREAM_POLL_RD;
}
#if MICROPY_PY_OS_DUPTERM
ret |= mp_uos_dupterm_poll(poll_flags);
#endif
return ret;
}
int mp_hal_stdin_rx_chr(void) {
for (;;) {
poll_cdc_interfaces();
int c = ringbuf_get(&stdin_ringbuf);
if (c != -1) {
return c;
}
#if MICROPY_PY_OS_DUPTERM
int dupterm_c = mp_uos_dupterm_rx_chr();
if (dupterm_c >= 0) {
return dupterm_c;
}
#endif
MICROPY_EVENT_POLL_HOOK
}
}
void mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
if (tud_cdc_connected()) {
for (size_t i = 0; i < len;) {
uint32_t n = len - i;
if (n > CFG_TUD_CDC_EP_BUFSIZE) {
n = CFG_TUD_CDC_EP_BUFSIZE;
}
while (n > tud_cdc_write_available()) {
MICROPY_EVENT_POLL_HOOK
}
uint32_t n2 = tud_cdc_write(str + i, n);
tud_cdc_write_flush();
i += n2;
}
}
#if MICROPY_PY_OS_DUPTERM
mp_uos_dupterm_tx_strn(str, len);
#endif
}