Skip to content

use rbuf for busio uart #1402

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Dec 13, 2018
Merged

use rbuf for busio uart #1402

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
e136222
use rbuf for busio uart
hathach Dec 13, 2018
b37b2fa
overwrite old data if fifo is full
hathach Dec 13, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
112 changes: 62 additions & 50 deletions ports/nrf/common-hal/busio/UART.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -52,21 +52,44 @@

static uint32_t get_nrf_baud (uint32_t baudrate);

static uint16_t ringbuf_count(ringbuf_t *r)
{
volatile int count = r->iput - r->iget;
if ( count < 0 ) {
count += r->size;
}

return (uint16_t) count;
}

static void ringbuf_clear(ringbuf_t *r)
{
r->iput = r->iget = 0;
}

static void uart_callback_irq (const nrfx_uarte_event_t * event, void * context) {
busio_uart_obj_t* self = (busio_uart_obj_t*) context;

switch ( event->type ) {
case NRFX_UARTE_EVT_RX_DONE:
self->rx_count = event->data.rxtx.bytes;
for(uint8_t i=0; i < event->data.rxtx.bytes; i++) {
if ( ringbuf_put(&self->rbuf, event->data.rxtx.p_data[i]) < 0 ) {
// if full overwrite old data
(void) ringbuf_get(&self->rbuf);
ringbuf_put(&self->rbuf, event->data.rxtx.p_data[i]);
}
}

// keep receiving
_VERIFY_ERR(nrfx_uarte_rx(&self->uarte, &self->rx_char, 1));
break;

case NRFX_UARTE_EVT_TX_DONE:
// nothing to do
break;

case NRFX_UARTE_EVT_ERROR:
if ( self->rx_count == -1 ) {
self->rx_count = 0;
}
// Handle error
break;

default:
Expand Down Expand Up @@ -110,12 +133,15 @@ void common_hal_busio_uart_construct (busio_uart_obj_t *self,

// Init buffer for rx
if ( rx != mp_const_none ) {
self->buffer = (uint8_t *) gc_alloc(receiver_buffer_size, false, false);
if ( !self->buffer ) {
self->rbuf.buf = (uint8_t *) gc_alloc(receiver_buffer_size, false, false);

if ( !self->rbuf.buf ) {
nrfx_uarte_uninit(&self->uarte);
mp_raise_msg(&mp_type_MemoryError, translate("Failed to allocate RX buffer"));
}
self->bufsize = receiver_buffer_size;

self->rbuf.size = receiver_buffer_size;
self->rbuf.iget = self->rbuf.iput = 0;

self->rx_pin_number = rx->number;
claim_pin(rx);
Expand All @@ -131,9 +157,8 @@ void common_hal_busio_uart_construct (busio_uart_obj_t *self,
self->baudrate = baudrate;
self->timeout_ms = timeout * 1000;

// queue 1-byte transfer for rx_characters_available()
self->rx_count = -1;
_VERIFY_ERR(nrfx_uarte_rx(&self->uarte, self->buffer, 1));
// Initial wait for incoming byte
_VERIFY_ERR(nrfx_uarte_rx(&self->uarte, &self->rx_char, 1));
}

bool common_hal_busio_uart_deinited(busio_uart_obj_t *self) {
Expand All @@ -147,7 +172,10 @@ void common_hal_busio_uart_deinit(busio_uart_obj_t *self) {
reset_pin_number(self->rx_pin_number);
self->tx_pin_number = NO_PIN;
self->rx_pin_number = NO_PIN;
gc_free(self->buffer);

gc_free(self->rbuf.buf);
self->rbuf.size = 0;
self->rbuf.iput = self->rbuf.iget = 0;
}
}

Expand All @@ -157,48 +185,33 @@ size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t
mp_raise_ValueError(translate("No RX pin"));
}

size_t remain = len;
size_t rx_bytes = 0;
uint64_t start_ticks = ticks_ms;

while ( 1 ) {
// Wait for on-going transfer to complete
while ( (self->rx_count == -1) && (ticks_ms - start_ticks < self->timeout_ms) ) {
// Wait for all bytes received or timeout
while ( (ringbuf_count(&self->rbuf) < len) && (ticks_ms - start_ticks < self->timeout_ms) ) {
#ifdef MICROPY_VM_HOOK_LOOP
MICROPY_VM_HOOK_LOOP;
// Allow user to break out of a timeout with a KeyboardInterrupt.
if (mp_hal_is_interrupted()) {
return 0;
}
#endif
}

// copy received data
if ( self->rx_count > 0 ) {
memcpy(data, self->buffer, self->rx_count);
data += self->rx_count;
remain -= self->rx_count;

self->rx_count = 0;
MICROPY_VM_HOOK_LOOP ;
// Allow user to break out of a timeout with a KeyboardInterrupt.
if ( mp_hal_is_interrupted() ) {
return 0;
}
#endif
}

// exit if complete or time up
if ( !remain || !(ticks_ms - start_ticks < self->timeout_ms) ) {
break;
}
// prevent conflict with uart irq
NVIC_DisableIRQ(nrfx_get_irq_number(self->uarte.p_reg));

// prepare next receiving
const size_t cnt = MIN(self->bufsize, remain);
self->rx_count = -1;
_VERIFY_ERR(nrfx_uarte_rx(&self->uarte, self->buffer, cnt));
// copy received data
rx_bytes = ringbuf_count(&self->rbuf);
rx_bytes = MIN(rx_bytes, len);
for ( uint16_t i = 0; i < rx_bytes; i++ ) {
data[i] = ringbuf_get(&self->rbuf);
}

// queue 1-byte transfer for rx_characters_available()
if ( self->rx_count == 0 ) {
self->rx_count = -1;
_VERIFY_ERR(nrfx_uarte_rx(&self->uarte, self->buffer, 1));
}
NVIC_EnableIRQ(nrfx_get_irq_number(self->uarte.p_reg));

return len - remain;
return rx_bytes;
}

// Write characters.
Expand Down Expand Up @@ -258,15 +271,14 @@ void common_hal_busio_uart_set_baudrate(busio_uart_obj_t *self, uint32_t baudrat
}

uint32_t common_hal_busio_uart_rx_characters_available(busio_uart_obj_t *self) {
return (self->rx_count > 0) ? self->rx_count : 0;
return ringbuf_count(&self->rbuf);
}

void common_hal_busio_uart_clear_rx_buffer(busio_uart_obj_t *self) {
// Discard received byte, and queue 1-byte transfer for rx_characters_available()
if ( self->rx_count > 0 ) {
self->rx_count = -1;
_VERIFY_ERR(nrfx_uarte_rx(&self->uarte, self->buffer, 1));
}
// prevent conflict with uart irq
NVIC_DisableIRQ(nrfx_get_irq_number(self->uarte.p_reg));
ringbuf_clear(&self->rbuf);
NVIC_EnableIRQ(nrfx_get_irq_number(self->uarte.p_reg));
}

bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
Expand Down
5 changes: 2 additions & 3 deletions ports/nrf/common-hal/busio/UART.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -41,9 +41,8 @@ typedef struct {
uint32_t baudrate;
uint32_t timeout_ms;

uint8_t* buffer;
uint32_t bufsize;
volatile int32_t rx_count;
ringbuf_t rbuf;
uint8_t rx_char; // EasyDMA buf

uint8_t tx_pin_number;
uint8_t rx_pin_number;
Expand Down