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#include "project.h"
#define BUFFER_SIZE 512
ring_t usart1_rx_ring;
static uint8_t usart1_rx_ring_buf[BUFFER_SIZE];
ring_t usart1_tx_ring;
static uint8_t usart1_tx_ring_buf[BUFFER_SIZE];
void
usart1_isr (void)
{
uint8_t data;
/* Check if we were called because of RXNE. */
if (((USART_CR1 (USART1) & USART_CR1_RXNEIE) != 0) &&
((USART_SR (USART1) & USART_SR_RXNE) != 0)) {
/* Retrieve the data from the peripheral. */
data = usart_recv (USART1);
ring_write_byte (&usart1_rx_ring, data);
}
/* Check if we were called because of TXE. */
if (((USART_CR1 (USART1) & USART_CR1_TXEIE) != 0) &&
((USART_SR (USART1) & USART_SR_TXE) != 0)) {
if (ring_read_byte (&usart1_tx_ring, &data)) {
/*No more data, Disable the TXE interrupt, it's no longer needed. */
USART_CR1 (USART1) &= ~USART_CR1_TXEIE;
} else
usart_send (USART1, data);
}
}
void usart1_kick (void)
{
if (!ring_empty (&usart1_tx_ring))
USART_CR1 (USART1) |= USART_CR1_TXEIE;
}
int
_write (int file, char *ptr, int len)
{
int ret;
if (file == 1) {
ret = ring_write (&usart1_tx_ring, (uint8_t *) ptr, len);
usart1_kick();
ring_write (&cdcacm_tx_ring, (uint8_t *) ptr, len);
if (ret < 0)
ret = -ret;
return ret;
}
errno = EIO;
return -1;
}
#define TRANSACT_TIMEOUT (HZ/2)
int usart_transact (uint32_t u, void *_b, size_t txl, size_t rxl)
{
uint8_t *b = _b;
uint32_t then = DWT_CYCCNT;
while (USART_SR (u) & USART_SR_RXNE)
(void) usart_recv (u);
while (txl--) {
while (! (USART_SR (USART1) & USART_SR_TXE))
if ((DWT_CYCCNT - then) > TRANSACT_TIMEOUT) return -1;
usart_send (u, * (b++));
}
b = _b;
while (rxl--) {
while (! (USART_SR (USART1) & USART_SR_RXNE))
if ((DWT_CYCCNT - then) > TRANSACT_TIMEOUT) return -1;
* (b++) = usart_recv (u);
}
return 0;
}
void
usart_init (void)
{
ring_init (&usart1_rx_ring, usart1_rx_ring_buf, sizeof (usart1_rx_ring_buf));
ring_init (&usart1_tx_ring, usart1_tx_ring_buf, sizeof (usart1_tx_ring_buf));
/* Enable the USART1 interrupt. */
nvic_enable_irq (NVIC_USART1_IRQ);
MAP_AF (USART1_TX);
MAP_AF_PU (USART1_RX);
/* Setup UART1 parameters. */
usart_set_baudrate (USART1, 115200);
usart_set_databits (USART1, 8);
usart_set_stopbits (USART1, USART_STOPBITS_1);
usart_set_parity (USART1, USART_PARITY_NONE);
usart_set_flow_control (USART1, USART_FLOWCONTROL_NONE);
usart_set_mode (USART1, USART_MODE_TX_RX);
/* Enable USART1 Receive interrupt. */
USART_CR1 (USART1) |= USART_CR1_RXNEIE;
/* Finally enable USART1. */
usart_enable (USART1);
MAP_AF (USART2_TX);
MAP_AF_PU (USART2_RX);
/* Setup UART1 parameters. */
usart_set_baudrate (USART2, 115200);
usart_set_databits (USART2, 8);
usart_set_stopbits (USART2, USART_STOPBITS_1);
usart_set_parity (USART2, USART_PARITY_NONE);
usart_set_flow_control (USART2, USART_FLOWCONTROL_NONE);
usart_set_mode (USART2, USART_MODE_TX_RX);
usart_enable (USART2);
MAP_AF (USART3_TX);
MAP_AF_PU (USART3_RX);
/* Setup UART1 parameters. */
usart_set_baudrate (USART3, 115200);
usart_set_databits (USART3, 8);
usart_set_stopbits (USART3, USART_STOPBITS_1);
usart_set_parity (USART3, USART_PARITY_NONE);
usart_set_flow_control (USART3, USART_FLOWCONTROL_NONE);
usart_set_mode (USART3, USART_MODE_TX_RX);
usart_enable (USART3);
}
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