int uart_init_blocking(uart_t uart, uint32_t baudrate)
{
USART_TypeDef *dev;
uint32_t bus_freq;
gpio_t rx_pin, tx_pin;
float divider;
uint16_t mantissa;
uint8_t fraction;
/* enable UART and port clocks and select devices */
switch (uart) {
#if UART_0_EN
case UART_0:
dev = UART_0_DEV;
rx_pin = UART_0_RX_PIN;
tx_pin = UART_0_TX_PIN;
bus_freq = UART_0_BUS_FREQ;
/* enable clocks */
UART_0_CLKEN();
break;
#endif
#if UART_1_EN
case UART_1:
dev = UART_1_DEV;
tx_pin = UART_1_TX_PIN;
rx_pin = UART_1_RX_PIN;
bus_freq = UART_1_BUS_FREQ;
/* enable clocks */
UART_1_CLKEN();
break;
#endif
default:
return -2;
}
/* configure RX and TX pin */
gpio_init_af(tx_pin, GPIO_AF_OUT_PP);
gpio_init(rx_pin, GPIO_DIR_IN, GPIO_NOPULL);
/* configure UART to mode 8N1 with given baudrate */
divider = ((float)bus_freq) / (16 * baudrate);
mantissa = (uint16_t)floorf(divider);
fraction = (uint8_t)floorf((divider - mantissa) * 16);
dev->BRR = 0;
dev->BRR |= ((mantissa & 0x0fff) << 4) | (0x0f & fraction);
/* enable receive and transmit mode */
dev->CR1 |= USART_CR1_UE | USART_CR1_TE | USART_CR1_RE;
return 0;
}
void uart_poweron(uart_t uart)
{
switch (uart) {
#if UART_0_EN
case UART_0:
UART_0_CLKEN();
break;
#endif
#if UART_1_EN
case UART_1:
UART_1_CLKEN();
break;
#endif
}
}
static int init_base(uart_t uart, uint32_t baudrate)
{
USART_TypeDef *dev = 0;
GPIO_TypeDef *port = 0;
uint32_t tx_pin = 0;
uint32_t rx_pin = 0;
uint8_t af = 0;
uint32_t clk = 0;
uint16_t mantissa;
uint8_t fraction;
switch (uart) {
#if UART_0_EN
case UART_0:
dev = UART_0_DEV;
port = UART_0_PORT;
clk = UART_0_CLK;
tx_pin = UART_0_TX_PIN;
rx_pin = UART_0_RX_PIN;
af = UART_0_AF;
UART_0_CLKEN();
UART_0_PORT_CLKEN();
break;
#endif
#if UART_1_EN
case UART_1:
dev = UART_1_DEV;
port = UART_1_PORT;
clk = UART_1_CLK;
tx_pin = UART_1_TX_PIN;
rx_pin = UART_1_RX_PIN;
af = UART_1_AF;
UART_1_CLKEN();
UART_1_PORT_CLKEN();
break;
#endif
#if UART_2_EN
case UART_2:
dev = UART_2_DEV;
port = UART_2_PORT;
clk = UART_2_CLK;
tx_pin = UART_2_TX_PIN;
rx_pin = UART_2_RX_PIN;
af = UART_2_AF;
UART_2_CLKEN();
UART_2_PORT_CLKEN();
break;
#endif
default:
return -1;
}
/* uart_configure RX and TX pins, set pin to use alternative function mode */
port->MODER &= ~(3 << (rx_pin * 2) | 3 << (tx_pin * 2));
port->MODER |= 2 << (rx_pin * 2) | 2 << (tx_pin * 2);
/* and assign alternative function */
if (rx_pin < 8) {
port->AFR[0] &= ~(0xf << (rx_pin * 4));
port->AFR[0] |= af << (rx_pin * 4);
}
else {
port->AFR[1] &= ~(0xf << ((rx_pin - 8) * 4));
port->AFR[1] |= af << ((rx_pin - 8) * 4);
}
if (tx_pin < 8) {
port->AFR[0] &= ~(0xf << (tx_pin * 4));
port->AFR[0] |= af << (tx_pin * 4);
}
else {
port->AFR[1] &= ~(0xf << ((tx_pin - 8) * 4));
port->AFR[1] |= af << ((tx_pin - 8) * 4);
}
/* uart_configure UART to mode 8N1 with given baudrate */
clk /= baudrate;
mantissa = (uint16_t)(clk / 16);
fraction = (uint8_t)(clk - (mantissa * 16));
dev->BRR = ((mantissa & 0x0fff) << 4) | (0x0f & fraction);
/* enable receive and transmit mode */
dev->CR3 = 0;
dev->CR2 = 0;
dev->CR1 |= USART_CR1_UE | USART_CR1_TE | USART_CR1_RE;
return 0;
}
static int init_base(uart_t uart, uint32_t baudrate)
{
USART_TypeDef *dev = 0;
gpio_t tx_pin = 0;
gpio_t rx_pin = 0;
gpio_af_t af = 0;
float clk = 0;
uint16_t mantissa;
uint8_t fraction;
switch (uart) {
#if UART_0_EN
case UART_0:
dev = UART_0_DEV;
clk = UART_0_CLK;
tx_pin = UART_0_TX_PIN;
rx_pin = UART_0_RX_PIN;
af = UART_0_AF;
UART_0_CLKEN();
break;
#endif
#if UART_1_EN
case UART_1:
dev = UART_1_DEV;
clk = UART_1_CLK;
tx_pin = UART_1_TX_PIN;
rx_pin = UART_1_RX_PIN;
af = UART_1_AF;
UART_1_CLKEN();
break;
#endif
#if UART_2_EN
case UART_2:
dev = UART_2_DEV;
clk = UART_2_CLK;
tx_pin = UART_2_TX_PIN;
rx_pin = UART_2_RX_PIN;
af = UART_2_AF;
UART_2_CLKEN();
break;
#endif
default:
return -1;
}
/* uart_configure RX and TX pins, set pin to use alternative function mode */
gpio_init(tx_pin, GPIO_DIR_OUT, GPIO_NOPULL);
gpio_init_af(tx_pin, af);
gpio_init(rx_pin, GPIO_DIR_IN, GPIO_NOPULL);
gpio_init_af(rx_pin, af);
/* uart_configure UART to mode 8N1 with given baudrate */
clk /= baudrate;
mantissa = (uint16_t)(clk / 16);
fraction = (uint8_t)(clk - (mantissa * 16));
dev->BRR = ((mantissa & 0x0fff) << 4) | (0x0f & fraction);
/* enable receive and transmit mode */
dev->CR3 = 0;
dev->CR2 = 0;
dev->CR1 |= USART_CR1_UE | USART_CR1_TE | USART_CR1_RE;
return 0;
}
static int init_base(uart_t uart, uint32_t baudrate)
{
switch (uart) {
#if UART_0_EN
case UART_0:
/* this implementation only supports 115200 baud */
if (baudrate != 115200) {
return -2;
}
/* power on UART device and select peripheral clock */
UART_0_CLKEN();
UART_0_CLKSEL();
/* set mode to 8N1 and enable access to divisor latch */
UART_0_DEV->LCR = ((0x3 << 0) | (1 << 7));
/* set baud rate registers (fixed for now) */
UART_0_DEV->DLM = 0;
UART_0_DEV->DLL = 13;
/* enable FIFOs */
UART_0_DEV->FCR = 1;
/* select and configure the pin for RX */
UART_0_RX_PINSEL &= ~(0x3 << (UART_0_RX_PIN * 2));
UART_0_RX_PINSEL |= (UART_0_AF << (UART_0_RX_PIN * 2));
UART_0_RX_PINMODE &= ~(0x3 << (UART_0_RX_PIN * 2));
UART_0_RX_PINMODE |= (0x2 << (UART_0_RX_PIN * 2));
/* select and configure the pin for TX */
UART_0_TX_PINSEL &= ~(0x3 << (UART_0_TX_PIN * 2));
UART_0_TX_PINSEL |= (UART_0_AF << (UART_0_TX_PIN * 2));
UART_0_TX_PINMODE &= ~(0x3 << (UART_0_TX_PIN * 2));
UART_0_TX_PINMODE |= (0x2 << (UART_0_TX_PIN * 2));
/* disable access to divisor latch */
UART_0_DEV->LCR &= ~(1 << 7);
break;
#endif
#if UART_1_EN
case UART_1:
/* this implementation only supports 115200 baud */
if (baudrate != 115200) {
return -2;
}
/* power on UART device and select peripheral clock */
UART_1_CLKEN();
UART_1_CLKSEL();
/* set mode to 8N1 and enable access to divisor latch */
UART_1_DEV->LCR = ((0x3 << 0) | (1 << 7));
/* set baud rate registers (fixed for now) */
UART_1_DEV->DLM = 0;
UART_1_DEV->DLL = 13;
/* enable FIFOs */
UART_1_DEV->FCR = 1;
/* select and configure the pin for RX */
UART_1_RX_PINSEL &= ~(0x3 << (UART_1_RX_PIN * 2));
UART_1_RX_PINSEL |= (UART_1_AF << (UART_1_RX_PIN * 2));
UART_1_RX_PINMODE &= ~(0x3 << (UART_1_RX_PIN * 2));
UART_1_RX_PINMODE |= (0x2 << (UART_1_RX_PIN * 2));
/* select and configure the pin for TX */
UART_1_TX_PINSEL &= ~(0x3 << (UART_1_TX_PIN * 2));
UART_1_TX_PINSEL |= (UART_1_AF << (UART_1_TX_PIN * 2));
UART_1_TX_PINMODE &= ~(0x3 << (UART_1_TX_PIN * 2));
UART_1_TX_PINMODE |= (0x2 << (UART_1_TX_PIN * 2));
/* disable access to divisor latch */
UART_1_DEV->LCR &= ~(1 << 7);
break;
#endif
default:
return -1;
}
return 0;
}
int uart_init_blocking(uart_t uart, uint32_t baudrate)
{
USART_TypeDef *dev;
GPIO_TypeDef *port;
uint32_t rx_pin, tx_pin, bus_freq;
float divider;
uint16_t mantissa;
uint8_t fraction;
/* enable UART and port clocks and select devices */
switch (uart) {
#if UART_0_EN
case UART_0:
dev = UART_0_DEV;
port = UART_0_PORT;
rx_pin = UART_0_RX_PIN;
tx_pin = UART_0_TX_PIN;
bus_freq = UART_0_BUS_FREQ;
/* enable clocks */
UART_0_CLKEN();
UART_0_PORT_CLKEN();
break;
#endif
#if UART_1_EN
case UART_1:
dev = UART_1_DEV;
port = UART_1_PORT;
tx_pin = UART_1_TX_PIN;
rx_pin = UART_1_RX_PIN;
bus_freq = UART_1_BUS_FREQ;
/* enable clocks */
UART_1_CLKEN();
UART_1_PORT_CLKEN();
break;
#endif
default:
return -2;
}
/* Configure USART Tx as alternate function push-pull and 50MHz*/
if (tx_pin < 8) {
port->CRL &= ~(0xf << (tx_pin * 4));
port->CRL |= (0xB << (tx_pin * 4));
}
else {
port->CRH &= ~(0xf << ((tx_pin-8) * 4));
port->CRH |= (0xB << ((tx_pin-8) * 4));
}
/* Configure USART Rx as floating input */
if (rx_pin < 8) {
port->CRL &= ~(0xf << (rx_pin * 4));
port->CRL |= (0x4 << (rx_pin * 4));
}
else {
port->CRH &= ~(0xf << ((rx_pin-8) * 4));
port->CRH |= (0x4 << ((rx_pin-8) * 4));
}
/* configure UART to mode 8N1 with given baudrate */
divider = ((float)bus_freq) / (16 * baudrate);
mantissa = (uint16_t)floorf(divider);
fraction = (uint8_t)floorf((divider - mantissa) * 16);
dev->BRR = 0;
dev->BRR |= ((mantissa & 0x0fff) << 4) | (0x0f & fraction);
/* enable receive and transmit mode */
dev->CR1 |= USART_CR1_UE | USART_CR1_TE | USART_CR1_RE;
return 0;
}
int uart_init_blocking(uart_t uart, uint32_t baudrate)
{
USART_TypeDef *dev = 0;
GPIO_TypeDef *port = 0;
uint32_t rx_pin = 0;
uint32_t tx_pin = 0;
uint8_t af = 0;
uint32_t mid;
uint16_t mantissa;
uint8_t fraction;
/* enable UART and port clocks and select devices */
switch (uart) {
#if UART_0_EN
case UART_0:
dev = UART_0_DEV;
port = UART_0_PORT;
rx_pin = UART_0_RX_PIN;
tx_pin = UART_0_TX_PIN;
af = UART_0_AF;
/* enable clocks */
UART_0_CLKEN();
UART_0_PORT_CLKEN();
break;
#endif
#if UART_1_EN
case UART_1:
dev = UART_1_DEV;
port = UART_1_PORT;
tx_pin = UART_1_TX_PIN;
rx_pin = UART_1_RX_PIN;
af = UART_1_AF;
/* enable clocks */
UART_1_CLKEN();
UART_1_PORT_CLKEN();
break;
#endif
}
/* configure RX and TX pins, set pin to use alternative function mode */
port->MODER &= ~(3 << (rx_pin * 2) | 3 << (tx_pin * 2));
port->MODER |= 2 << (rx_pin * 2) | 2 << (tx_pin * 2);
/* and assign alternative function */
if (rx_pin < 8) {
port->AFR[0] &= ~(0xf << (rx_pin * 4));
port->AFR[0] |= af << (rx_pin * 4);
}
else {
port->AFR[1] &= ~(0xf << ((rx_pin - 16) * 4));
port->AFR[1] |= af << ((rx_pin - 16) * 4);
}
if (tx_pin < 8) {
port->AFR[0] &= ~(0xf << (tx_pin * 4));
port->AFR[0] |= af << (tx_pin * 4);
}
else {
port->AFR[1] &= ~(0xf << ((tx_pin - 16) * 4));
port->AFR[1] |= af << ((tx_pin - 16) * 4);
}
/* configure UART to mode 8N1 with given baudrate */
mid = (CLOCK_CORECLOCK / baudrate);
mantissa = (uint16_t)(mid / 16);
fraction = (uint8_t)(mid - (mantissa * 16));
dev->BRR = ((mantissa & 0x0fff) << 4) | (0x0f & fraction);
/* enable receive and transmit mode */
dev->CR1 |= USART_CR1_UE | USART_CR1_TE | USART_CR1_RE;
return 0;
}
int init_base(uart_t uart, uint32_t baudrate)
{
USART_TypeDef *dev = 0;
GPIO_TypeDef *port = 0;
uint32_t rx_pin = 0;
uint32_t tx_pin = 0;
uint8_t af = 0;
uint32_t mid;
uint16_t mantissa;
uint8_t fraction;
/* enable UART and port clocks and select devices */
switch (uart) {
#if UART_0_EN
case UART_0:
dev = UART_0_DEV;
port = UART_0_PORT;
rx_pin = UART_0_RX_PIN;
tx_pin = UART_0_TX_PIN;
af = UART_0_AF;
/* enable clocks */
UART_0_CLKEN();
UART_0_PORT_CLKEN();
break;
#endif
#if UART_1_EN
case UART_1:
dev = UART_1_DEV;
port = UART_1_PORT;
tx_pin = UART_1_TX_PIN;
rx_pin = UART_1_RX_PIN;
af = UART_1_AF;
/* enable clocks */
UART_1_CLKEN();
UART_1_PORT_CLKEN();
break;
#endif
default:
return -1;
}
/* Make sure port and dev are != NULL here, i.e. that the variables are
* assigned in all non-returning branches of the switch at the top of this
* function. */
assert(port != NULL);
assert(dev != NULL);
/* configure RX and TX pins, set pin to use alternative function mode */
port->MODER &= ~(3 << (rx_pin * 2) | 3 << (tx_pin * 2));
port->MODER |= 2 << (rx_pin * 2) | 2 << (tx_pin * 2);
/* and assign alternative function */
if (rx_pin < 8) {
port->AFR[0] &= ~(0xf << (rx_pin * 4));
port->AFR[0] |= af << (rx_pin * 4);
}
else {
port->AFR[1] &= ~(0xf << ((rx_pin - 8) * 4));
port->AFR[1] |= af << ((rx_pin - 8) * 4);
}
if (tx_pin < 8) {
port->AFR[0] &= ~(0xf << (tx_pin * 4));
port->AFR[0] |= af << (tx_pin * 4);
}
else {
port->AFR[1] &= ~(0xf << ((tx_pin - 8) * 4));
port->AFR[1] |= af << ((tx_pin - 8) * 4);
}
/* configure UART to mode 8N1 with given baudrate */
mid = (CLOCK_CORECLOCK / baudrate);
mantissa = (uint16_t)(mid / 16);
fraction = (uint8_t)(mid - (mantissa * 16));
dev->BRR = ((mantissa & 0x0fff) << 4) | (0x0f & fraction);
/* enable receive and transmit mode */
dev->CR1 |= USART_CR1_UE | USART_CR1_TE | USART_CR1_RE;
return 0;
}
