Atmosphere/exosphere/src/uart.c
2019-04-07 19:00:49 -07:00

81 lines
2.9 KiB
C

/*
* Copyright (c) 2018 naehrwert
* Copyright (c) 2018-2019 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "timers.h"
#include "uart.h"
#include "misc.h"
void uart_select(UartDevice dev) {
unsigned int id = (unsigned int)dev;
PINMUX_AUX_UARTn_TX_0(id) = 0; /* UART */
PINMUX_AUX_UARTn_RX_0(id) = 0x48; /* UART, enable, pull up */
PINMUX_AUX_UARTn_RTS_0(id) = 0; /* UART */
PINMUX_AUX_UARTn_CTS_0(id) = 0x44; /* UART, enable, pull down */
}
void uart_init(UartDevice dev, uint32_t baud) {
volatile uart_t *uart = get_uart_device(dev);
/* Set baud rate. */
uint32_t rate = (8 * baud + 408000000) / (16 * baud);
uart->UART_LCR = UART_LCR_DLAB; /* Enable DLAB. */
uart->UART_THR_DLAB = (uint8_t)rate; /* Divisor latch LSB. */
uart->UART_IER_DLAB = (uint8_t)(rate >> 8); /* Divisor latch MSB. */
uart->UART_LCR = 0; /* Diable DLAB. */
/* Setup UART in fifo mode. */
uart->UART_IER_DLAB = 0;
uart->UART_IIR_FCR = UART_FCR_FCR_EN_FIFO | UART_FCR_RX_CLR | UART_FCR_TX_CLR; /* Enable and clear TX and RX FIFOs. */
uart->UART_LSR;
wait(3 * ((baud + 999999) / baud));
uart->UART_LCR = UART_LCR_WD_LENGTH_8; /* Set word length 8. */
uart->UART_MCR = 0;
uart->UART_MSR = 0;
uart->UART_IRDA_CSR = 0;
uart->UART_RX_FIFO_CFG = 1; /* Set RX_FIFO trigger level */
uart->UART_MIE = 0;
uart->UART_ASR = 0;
}
/* This function blocks until the UART device (dev) is in the desired state (status). Make sure the desired state can be reached! */
void uart_wait_idle(UartDevice dev, UartVendorStatus status) {
while (!(get_uart_device(dev)->UART_VENDOR_STATUS & status)) {
/* Wait */
}
}
void uart_send(UartDevice dev, const void *buf, size_t len) {
volatile uart_t *uart = get_uart_device(dev);
for (size_t i = 0; i < len; i++) {
while (uart->UART_LSR & UART_LSR_TX_FIFO_FULL) {
/* Wait until the TX FIFO isn't full */
}
uart->UART_THR_DLAB = *((const uint8_t *)buf + i);
}
}
void uart_recv(UartDevice dev, void *buf, size_t len) {
volatile uart_t *uart = get_uart_device(dev);
for (size_t i = 0; i < len; i++) {
while (uart->UART_LSR & UART_LSR_RX_FIFO_EMPTY) {
/* Wait until the RX FIFO isn't empty */
}
*((uint8_t *)buf + i) = uart->UART_THR_DLAB;
}
}