diff --git a/src/soc/qualcomm/sdm845/Makefile.inc b/src/soc/qualcomm/sdm845/Makefile.inc index 1fddb56345..e603177317 100644 --- a/src/soc/qualcomm/sdm845/Makefile.inc +++ b/src/soc/qualcomm/sdm845/Makefile.inc @@ -7,6 +7,7 @@ bootblock-y += spi.c bootblock-y += mmu.c bootblock-y += timer.c bootblock-y += gpio.c +bootblock-$(CONFIG_DRIVERS_UART) += uart_bitbang.c ################################################################################ verstage-y += spi.c diff --git a/src/soc/qualcomm/sdm845/uart_bitbang.c b/src/soc/qualcomm/sdm845/uart_bitbang.c new file mode 100644 index 0000000000..f39e0ef1ae --- /dev/null +++ b/src/soc/qualcomm/sdm845/uart_bitbang.c @@ -0,0 +1,45 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2018 Google LLC + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that 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. + */ + +#include +#include +#include + +#define UART_TX_PIN GPIO(4) + +static void set_tx(int line_state) +{ + gpio_set(UART_TX_PIN, line_state); +} + +void uart_init(int idx) +{ + gpio_output(UART_TX_PIN, 1); +} + +void uart_tx_byte(int idx, unsigned char data) +{ + uart_bitbang_tx_byte(data, set_tx); +} + +void uart_tx_flush(int idx) +{ + /* unnecessary, PIO Tx means transaction is over when tx_byte returns */ +} + +unsigned char uart_rx_byte(int idx) +{ + return 0; /* not implemented */ +}