2 * Copyright (c) 2015, Linaro Limited
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27 #include <platform_config.h>
29 #include <drivers/serial8250_uart.h>
34 /* uart register defines */
46 /* uart status register bits */
47 #define LSR_TEMT 0x40 /* Transmitter empty */
48 #define LSR_THRE 0x20 /* Transmit-hold-register empty */
49 #define LSR_EMPTY (LSR_TEMT | LSR_THRE)
50 #define LSR_DR 0x01 /* DATA Ready */
52 void serial8250_uart_init(vaddr_t __unused base,
53 uint32_t __unused uart_clk, uint32_t __unused baud_rate)
56 * do nothing, debug uart(uart0) share with normal world,
57 * everything for uart0 is ready now.
61 void serial8250_uart_flush_tx_fifo(vaddr_t base)
64 uint8_t state = read8(base + UART_LSR);
66 /* waiting transmit fifo empty */
67 if ((state & LSR_EMPTY) == LSR_EMPTY)
72 bool serial8250_uart_have_rx_data(vaddr_t base)
74 return (read32(base + UART_LSR) & LSR_DR);
77 void serial8250_uart_putc(int ch, vaddr_t base)
79 serial8250_uart_flush_tx_fifo(base);
81 /* write out charset to transmit fifo */
82 write8(ch, base + UART_THR);
85 int serial8250_uart_getchar(vaddr_t base)
87 while (!serial8250_uart_have_rx_data(base)) {
88 /* transmit fifo is empty, waiting again. */
91 return read8(base + UART_RHR);