Function uart_write

core/uart.c:371–452

Write to the 0xE000 range of ports */

/* Write to the 0xE000 range of ports */
static void uart_write(const uint16_t pio, const uint8_t byte, bool poke) {
    (void)poke;
    switch (pio) {
        case 0x00:
            if (unlikely(uart.lcr >> 7 & 1)) {
                uart.divisor &= ~0xFF;
                uart.divisor |= byte;
                uart_set_timer(true);
            } else {
                /* FIFO write */
                if (uart.tfve != (uart_fifo_enabled() ? UART_FIFO_DEPTH : 1)) {
                    uart.txfifo[(uart.tfvi + uart.tfve++) & (UART_FIFO_DEPTH - 1)] = byte;
                    uart.lsr &= ~(1 << 6 | 1 << 5);
                    uart.isr &= ~(1 << 1);
                    if (!likely(uart.txActive)) {
                        uart_next_transmit();
                        uart.txActive = true;
                        uart_set_timer(true);
                    }
                    intrpt_set(INT_UART, uart.ier & uart.isr);
                }
            }
            break;
        case 0x04:
            if (unlikely(uart.lcr >> 7 & 1)) {
                uart.divisor &= ~(0xFF << 8);
                uart.divisor |= byte << 8;
                uart_set_timer(true);
            }
            else {
                uart.ier = byte;
                intrpt_set(INT_UART, uart.ier & uart.isr);
            }
            break;
        case 0x08: {
            const uint8_t diff = uart.fcr ^ byte;
            uart.fcr = byte & ~(1 << 2 | 1 << 1);
            if (diff & (1 << 2 | 1 << 0)) {
                /* Clear TX FIFO */
                uart.tfvi = uart.tfve = 0;
                uart.isr |= 1 << 1;
                uart.lsr |= (1 << 6 | 1 << 5);
                uart.lsr &= ~(uart.txActive << 6);
            }
            if (diff & (1 << 1 | 1 << 0)) {
                /* Clear RX FIFO */
                memset(&uart.rxstat, 0, sizeof(uart.rxstat));
                uart.rfvi = uart.rfve = uart.rxstatCount = 0;
                uart.lsr &= ~(1 << 7 | 1 << 0);
                uart_reset_rx_timeout();
            }
            uart_update_rxfifo_trigger();
            intrpt_set(INT_UART, uart.ier & uart.isr);
            break;
        }
        case 0x0C: {
            uint8_t lcrDiff = uart.lcr ^ byte;
            uart.lcr = byte;