circuitpython/atmel-samd/mphalport.c
Scott Shawcroft e3f9ee839a Add frequency changing support to PWMOut.
You can either set it once up front, or set variable_frequency on custruction to
indicate that the frequency must be able to change. This informs whether a timer
can be shared amongst pins.

This also adds persistent clock calibration on atmel-samd. Once the device has
synced its clock frequency over USB it will remember that config value until USB
is used again. This helps ensure the clock frequency is similar on and off USB.

Lastly, this also corrects time.sleep() when on USB by correcting the tick counter.
2017-01-30 15:02:01 -08:00

261 lines
7.6 KiB
C

#include <string.h>
#include "autoreset.h"
#include "compiler.h"
#include "asf/common/services/sleepmgr/sleepmgr.h"
#include "asf/common/services/usb/class/cdc/device/udi_cdc.h"
#include "asf/common2/services/delay/delay.h"
#include "asf/sam0/drivers/port/port.h"
#include "asf/sam0/drivers/sercom/usart/usart.h"
#include "lib/mp-readline/readline.h"
#include "lib/utils/interrupt_char.h"
#include "py/mphal.h"
#include "py/mpstate.h"
#include "py/smallint.h"
#include "shared-bindings/time/__init__.h"
#include "mpconfigboard.h"
#include "mphalport.h"
// Store received characters on our own so that we can filter control characters
// and act immediately on CTRL-C for example.
// This is adapted from asf/thirdparty/wireless/addons/sio2host
// Receive buffer
static uint8_t usb_rx_buf[USB_RX_BUF_SIZE];
// Receive buffer head
static volatile uint8_t usb_rx_buf_head;
// Receive buffer tail
static volatile uint8_t usb_rx_buf_tail;
// Number of bytes in receive buffer
volatile uint8_t usb_rx_count;
volatile bool mp_cdc_enabled = false;
extern struct usart_module usart_instance;
// Read by main to know when USB is connected.
volatile bool mp_msc_enabled = false;
bool mp_msc_enable()
{
mp_msc_enabled = true;
return true;
}
void mp_msc_disable()
{
mp_msc_enabled = false;
}
bool mp_cdc_enable(uint8_t port)
{
mp_cdc_enabled = false;
return true;
}
void mp_cdc_disable(uint8_t port)
{
mp_cdc_enabled = false;
}
void usb_dtr_notify(uint8_t port, bool set) {
mp_cdc_enabled = set;
}
void usb_rts_notify(uint8_t port, bool set) {
return;
}
void usb_rx_notify(void)
{
irqflags_t flags;
if (mp_cdc_enabled) {
while (udi_cdc_is_rx_ready()) {
uint8_t c;
// Introduce a critical section to avoid buffer corruption. We use
// cpu_irq_save instead of cpu_irq_disable because we don't know the
// current state of IRQs. They may have been turned off already and
// we don't want to accidentally turn them back on.
flags = cpu_irq_save();
// If our buffer is full, then don't get another character otherwise
// we'll lose a previous character.
if (usb_rx_count >= USB_RX_BUF_SIZE) {
cpu_irq_restore(flags);
break;
}
uint8_t current_tail = usb_rx_buf_tail;
// Pretend we've received a character so that any nested calls to
// this function have to consider the spot we've reserved.
if ((USB_RX_BUF_SIZE - 1) == usb_rx_buf_tail) {
// Reached the end of buffer, revert back to beginning of
// buffer.
usb_rx_buf_tail = 0x00;
} else {
usb_rx_buf_tail++;
}
// The count of characters present in receive buffer is
// incremented.
usb_rx_count++;
// WARNING(tannewt): This call can call us back with the next
// character!
c = udi_cdc_getc();
if (c == mp_interrupt_char) {
// We consumed a character rather than adding it to the rx
// buffer so undo the modifications we made to count and the
// tail.
usb_rx_count--;
usb_rx_buf_tail = current_tail;
cpu_irq_restore(flags);
mp_keyboard_interrupt();
// Don't put the interrupt into the buffer, just continue.
continue;
}
// We put the next character where we expected regardless of whether
// the next character was already loaded in the buffer.
usb_rx_buf[current_tail] = c;
cpu_irq_restore(flags);
}
}
}
int receive_usb(void) {
if (usb_rx_count == 0) {
return 0;
}
// Disable autoreset if someone is using the repl.
autoreset_disable();
// Copy from head.
cpu_irq_disable();
int data = usb_rx_buf[usb_rx_buf_head];
usb_rx_buf_head++;
usb_rx_count--;
if ((USB_RX_BUF_SIZE) == usb_rx_buf_head) {
usb_rx_buf_head = 0;
}
cpu_irq_enable();
// Call usb_rx_notify if we just emptied a spot in the buffer.
if (usb_rx_count == USB_RX_BUF_SIZE - 1) {
usb_rx_notify();
}
return data;
}
int mp_hal_stdin_rx_chr(void) {
for (;;) {
#ifdef MICROPY_VM_HOOK_LOOP
MICROPY_VM_HOOK_LOOP
#endif
#ifdef USB_REPL
if (reset_next_character) {
return CHAR_CTRL_D;
}
if (usb_rx_count > 0) {
#ifdef MICROPY_HW_LED_RX
port_pin_toggle_output_level(MICROPY_HW_LED_RX);
#endif
return receive_usb();
}
#endif
#ifdef UART_REPL
uint16_t temp;
if (usart_read_wait(&usart_instance, &temp) == STATUS_OK) {
#ifdef MICROPY_HW_LED_RX
port_pin_toggle_output_level(MICROPY_HW_LED_RX);
#endif
return temp;
}
#endif
// TODO(tannewt): Switch to callback/interrupt based UART so it can work
// with the sleepmgr.
sleepmgr_enter_sleep();
}
}
void mp_hal_stdout_tx_strn(const char *str, size_t len) {
#ifdef MICROPY_HW_LED_TX
port_pin_toggle_output_level(MICROPY_HW_LED_TX);
#endif
#ifdef UART_REPL
usart_write_buffer_wait(&usart_instance, (uint8_t*) str, len);
#endif
#ifdef USB_REPL
// Always make sure there is enough room in the usb buffer for the outgoing
// string. If there isn't we risk getting caught in a loop within the usb
// code as it tries to send all the characters it can't buffer.
uint32_t start = 0;
uint64_t start_tick = common_hal_time_monotonic();
uint64_t duration = 0;
if (mp_cdc_enabled) {
while (start < len && duration < 10) {
uint8_t buffer_space = udi_cdc_get_free_tx_buffer();
uint8_t transmit = min(len - start, buffer_space);
if (transmit > 0) {
if (udi_cdc_write_buf(str + start, transmit) > 0) {
// It didn't transmit successfully so give up.
break;
}
}
start += transmit;
#ifdef MICROPY_VM_HOOK_LOOP
MICROPY_VM_HOOK_LOOP
#endif
duration = (common_hal_time_monotonic() - start_tick);
}
}
#endif
}
void mp_hal_delay_ms(mp_uint_t delay) {
// If mass storage is enabled measure the time ourselves and run any mass
// storage transactions in the meantime.
if (mp_msc_enabled) {
uint64_t start_tick = ticks_ms;
uint64_t duration = 0;
while (duration < delay) {
#ifdef MICROPY_VM_HOOK_LOOP
MICROPY_VM_HOOK_LOOP
#endif
// Check to see if we've been CTRL-Ced by autoreset or the user.
if(MP_STATE_VM(mp_pending_exception) == MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception))) {
break;
}
duration = (ticks_ms - start_tick);
}
} else {
delay_ms(delay);
}
}
void mp_hal_delay_us(mp_uint_t delay) {
delay_us(delay);
}
// Interrupt flags that will be saved and restored during disable/Enable
// interrupt functions below.
static irqflags_t irq_flags;
void mp_hal_disable_all_interrupts(void) {
// Disable all interrupt sources for timing critical sections.
// Disable ASF-based interrupts.
irq_flags = cpu_irq_save();
}
void mp_hal_enable_all_interrupts(void) {
// Enable all interrupt sources after timing critical sections.
// Restore ASF-based interrupts.
cpu_irq_restore(irq_flags);
}