src/soc/qualcomm/sdm845/uart_bitbang.c

   1 /* This file is part of the coreboot project. */
   2 /* SPDX-License-Identifier: GPL-2.0-only */
   3
   4 #include <console/uart.h>
   5 #include <gpio.h>
   6 #include <types.h>
   7
   8 #define UART_TX_PIN GPIO(4)
   9
  10 static void set_tx(int line_state)
  11 {
  12         gpio_set(UART_TX_PIN, line_state);
  13 }
  14
  15 void uart_init(int idx)
  16 {
  17         gpio_output(UART_TX_PIN, 1);
  18 }
  19
  20 void uart_tx_byte(int idx, unsigned char data)
  21 {
  22         uart_bitbang_tx_byte(data, set_tx);
  23 }
  24
  25 void uart_tx_flush(int idx)
  26 {
  27         /* unnecessary, PIO Tx means transaction is over when tx_byte returns */
  28 }
  29
  30 unsigned char uart_rx_byte(int idx)
  31 {
  32         return 0;       /* not implemented */
  33 }