#include "timers.h"
#include "uart.h"
#include "misc.h"

/* Adapted from https://github.com/nwert/hekate/blob/master/hwinit/uart.c */

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 = 0x80; /* 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 = 7; /* Enable and clear TX and RX FIFOs. */
    uart->UART_LSR;
    wait(3 * ((baud + 999999) / baud));
    uart->UART_LCR = 3; /* Set word length 8. */
    uart->UART_MCR = 0;
    uart->UART_MSR = 0;
    uart->UART_IRDA_CSR = 0;
    uart->UART_RX_FIFO_CFG = 1;
    uart->UART_MIE = 0;
    uart->UART_ASR = 0;
}

void uart_wait_idle(UartDevice dev, uint32_t which) {
    while (!(get_uart_device(dev)->UART_VENDOR_STATUS & which)) {
        /* 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_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_RX_FIFO_EMPTY) {
            /* Wait until the RX FIFO isn't empty */
        }
         *((uint8_t *)buf + i) = uart->UART_THR_DLAB;
    }
}