diff options
Diffstat (limited to 'app/usart.c')
| -rw-r--r-- | app/usart.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/app/usart.c b/app/usart.c new file mode 100644 index 0000000..e0a80b1 --- /dev/null +++ b/app/usart.c @@ -0,0 +1,191 @@ +#include "project.h" + +#define BUFFER_SIZE 256 +#define BIG_BUFFER_SIZE 600 + +ring_t rx1_ring; +static uint8_t rx1_ring_buf[BUFFER_SIZE]; + +ring_t tx1_ring; +static uint8_t tx1_ring_buf[BUFFER_SIZE]; + +ring_t rx2_ring; +static uint8_t rx2_ring_buf[BUFFER_SIZE]; + +ring_t tx2_ring; +static uint8_t tx2_ring_buf[BIG_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 (&rx1_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 (&tx1_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 +usart2_isr (void) +{ + uint8_t data; + + /* Check if we were called because of RXNE. */ + if (((USART_CR1 (USART2) & USART_CR1_RXNEIE) != 0) && + ((USART_SR (USART2) & USART_SR_RXNE) != 0)) + { + + /* Retrieve the data from the peripheral. */ + data = usart_recv (USART2); + + ring_write_byte (&rx2_ring, data); + } + + /* Check if we were called because of TXE. */ + if (((USART_CR1 (USART2) & USART_CR1_TXEIE) != 0) && + ((USART_SR (USART2) & USART_SR_TXE) != 0)) + { + + if (ring_read_byte (&tx2_ring, &data)) + { + /*No more data, Disable the TXE interrupt, it's no longer needed. */ + USART_CR1 (USART2) &= ~USART_CR1_TXEIE; + } + else + { + usart_send_blocking (USART2, data); + } + } + +} + +int +_write (int file, char *ptr, int len) +{ + int ret; + + if (file == 1) + { + ret = ring_write (&tx1_ring, (uint8_t *) ptr, len); + + if (ret < 0) + ret = -ret; + + USART_CR1 (USART1) |= USART_CR1_TXEIE; + return ret; + } + + errno = EIO; + return -1; +} + +void +usart1_queue (uint8_t d) +{ + ring_write_byte (&tx1_ring, d); + USART_CR1 (USART1) |= USART_CR1_TXEIE; +} + + +void +usart2_queue (uint8_t d) +{ + ring_write_byte (&tx2_ring, d); + USART_CR1 (USART2) |= USART_CR1_TXEIE; +} + +void +usart2_drain (void) +{ + while (!ring_empty (&tx2_ring)); +} + +void +usart1_drain (void) +{ + while (!ring_empty (&tx1_ring)); +} + + + +void +usart_init (void) +{ + rcc_periph_clock_enable (RCC_USART1); + rcc_periph_clock_enable (RCC_USART2); + rcc_periph_clock_enable (RCC_USART3); + + ring_init (&rx1_ring, rx1_ring_buf, sizeof (rx1_ring_buf)); + ring_init (&tx1_ring, tx1_ring_buf, sizeof (tx1_ring_buf)); + + ring_init (&rx2_ring, rx2_ring_buf, sizeof (rx2_ring_buf)); + ring_init (&tx2_ring, tx2_ring_buf, sizeof (tx2_ring_buf)); + + + /* Enable the USART1,2 interrupt. */ + nvic_enable_irq (NVIC_USART1_IRQ); + nvic_enable_irq (NVIC_USART2_IRQ); + + /* Map pins, and set usart2 to have pull ups */ + gpio_set_mode (GPIOA, GPIO_MODE_OUTPUT_50_MHZ, + GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX); + gpio_set_mode (GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, + GPIO_USART1_RX); + + gpio_set_mode (GPIOA, GPIO_MODE_OUTPUT_50_MHZ, + GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX); + gpio_set_mode (GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, + GPIO_USART2_RX); + gpio_set (GPIOA, GPIO_USART2_RX); + + + /* Setup UART1 parameters. */ + usart_set_baudrate (USART1, 38400); + 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); + + /* Setup UART2 parameters. */ + usart_set_baudrate (USART2, 9600); + 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); + + + /* Enable USART1,2 Receive interrupt. */ + USART_CR1 (USART1) |= USART_CR1_RXNEIE; + USART_CR1 (USART2) |= USART_CR1_RXNEIE; + + /* Finally enable the USARTs. */ + usart_enable (USART1); + usart_enable (USART2); +} |