Atmosphere/sept/sept-secondary/src/uart.c

119 lines
4 KiB
C
Raw Normal View History

/*
* Copyright (c) 2018 naehrwert
2019-04-08 02:00:49 +00:00
* 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 "uart.h"
#include "timers.h"
2019-07-21 18:18:15 +00:00
#include "pinmux.h"
void uart_config(UartDevice dev) {
volatile tegra_pinmux_t *pinmux = pinmux_get_regs();
switch (dev) {
case UART_A:
2019-07-21 20:21:13 +00:00
pinmux->uart1_tx = 0;
pinmux->uart1_rx = (PINMUX_INPUT | PINMUX_PULL_UP);
2019-07-21 18:18:15 +00:00
pinmux->uart1_rts = 0;
pinmux->uart1_cts = (PINMUX_INPUT | PINMUX_PULL_DOWN);
break;
case UART_B:
2019-07-21 20:21:13 +00:00
pinmux->uart2_tx = 0;
pinmux->uart2_rx = (PINMUX_INPUT | PINMUX_PULL_UP);
2019-07-21 18:18:15 +00:00
pinmux->uart2_rts = 0;
pinmux->uart2_cts = (PINMUX_INPUT | PINMUX_PULL_DOWN);
break;
case UART_C:
2019-07-21 20:21:13 +00:00
pinmux->uart3_tx = 0;
pinmux->uart3_rx = (PINMUX_INPUT | PINMUX_PULL_UP);
2019-07-21 18:18:15 +00:00
pinmux->uart3_rts = 0;
pinmux->uart3_cts = (PINMUX_INPUT | PINMUX_PULL_DOWN);
break;
case UART_D:
2019-07-21 20:21:13 +00:00
pinmux->uart4_tx = 0;
pinmux->uart4_rx = (PINMUX_INPUT | PINMUX_PULL_UP);
2019-07-21 18:18:15 +00:00
pinmux->uart4_rts = 0;
pinmux->uart4_cts = (PINMUX_INPUT | PINMUX_PULL_DOWN);
break;
case UART_E:
/* Unused. */
break;
default: break;
}
}
void uart_init(UartDevice dev, uint32_t baud) {
volatile tegra_uart_t *uart = uart_get_regs(dev);
2019-07-21 18:18:15 +00:00
/* Wait for idle state. */
uart_wait_idle(dev, UART_VENDOR_STATE_TX_IDLE);
/* Calculate baud rate. */
uint32_t rate = (8 * baud + 408000000) / (16 * baud);
2019-07-21 18:18:15 +00:00
/* Setup UART in FIFO mode. */
uart->UART_IER_DLAB = 0;
uart->UART_MCR = 0;
2019-07-21 18:18:15 +00:00
uart->UART_LCR = (UART_LCR_DLAB | UART_LCR_WD_LENGTH_8); /* Enable DLAB and set word length 8. */
uart->UART_THR_DLAB = (uint8_t)rate; /* Divisor latch LSB. */
uart->UART_IER_DLAB = (uint8_t)(rate >> 8); /* Divisor latch MSB. */
uart->UART_LCR &= ~(UART_LCR_DLAB); /* Disable DLAB. */
/* Flush FIFO. */
uart->UART_IIR_FCR = (UART_FCR_FCR_EN_FIFO | UART_FCR_RX_CLR | UART_FCR_TX_CLR); /* Enable and clear TX and RX FIFOs. */
udelay(3 * ((baud + 999999) / baud));
/* Wait for idle state. */
uart_wait_idle(dev, UART_VENDOR_STATE_TX_IDLE | UART_VENDOR_STATE_RX_IDLE);
}
2019-07-21 18:18:15 +00:00
/* This function blocks until the UART device is in the desired state. */
void uart_wait_idle(UartDevice dev, UartVendorStatus status) {
2019-07-21 18:18:15 +00:00
volatile tegra_uart_t *uart = uart_get_regs(dev);
if (status & UART_VENDOR_STATE_TX_IDLE) {
while (!(uart->UART_LSR & UART_LSR_TMTY)) {
/* Wait */
}
}
if (status & UART_VENDOR_STATE_RX_IDLE) {
while (uart->UART_LSR & UART_LSR_RDR) {
/* Wait */
}
}
}
void uart_send(UartDevice dev, const void *buf, size_t len) {
volatile tegra_uart_t *uart = uart_get_regs(dev);
for (size_t i = 0; i < len; i++) {
2019-07-21 18:18:15 +00:00
while (!(uart->UART_LSR & UART_LSR_THRE)) {
/* Wait until it's possible to send data. */
}
uart->UART_THR_DLAB = *((const uint8_t *)buf + i);
}
}
void uart_recv(UartDevice dev, void *buf, size_t len) {
volatile tegra_uart_t *uart = uart_get_regs(dev);
for (size_t i = 0; i < len; i++) {
2019-07-21 18:18:15 +00:00
while (!(uart->UART_LSR & UART_LSR_RDR)) {
/* Wait until it's possible to receive data. */
}
*((uint8_t *)buf + i) = uart->UART_THR_DLAB;
}
}