From c8cbc97e0da42d9047ae4f7cfd4c0940b17e15e8 Mon Sep 17 00:00:00 2001
From: Dong Heng <dongheng@espressif.com>
Date: Fri, 7 Sep 2018 15:45:41 +0800
Subject: [PATCH] feat(esp8266): Add configuration for UART swap I/O pins

---
 components/bootloader_support/src/bootloader_init.c | 10 ++++++++++
 components/esp8266/Kconfig                          |  6 ++++++
 2 files changed, 16 insertions(+)

diff --git a/components/bootloader_support/src/bootloader_init.c b/components/bootloader_support/src/bootloader_init.c
index 77edb7e7..a7e518bb 100644
--- a/components/bootloader_support/src/bootloader_init.c
+++ b/components/bootloader_support/src/bootloader_init.c
@@ -568,6 +568,16 @@ static void update_flash_config(const esp_image_header_t* pfhdr);
 
 static void uart_console_configure(void)
 {
+#if CONFIG_CONSOLE_UART_SWAP_IO
+    while (READ_PERI_REG(UART_STATUS(0)) & (UART_TXFIFO_CNT << UART_TXFIFO_CNT_S));
+
+    PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTCK_U, FUNC_UART0_CTS);
+    PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDO_U, FUNC_UART0_RTS);
+
+    // UART0: TXD <-> RTS and RXD <-> CTS
+    SET_PERI_REG_MASK(UART_SWAP_REG, 0x4);
+#endif
+
 #if CONFIG_CONSOLE_UART_NUM == 1
     PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO2_U, FUNC_U1TXD_BK);
 
diff --git a/components/esp8266/Kconfig b/components/esp8266/Kconfig
index bf1a79f8..a69952cc 100644
--- a/components/esp8266/Kconfig
+++ b/components/esp8266/Kconfig
@@ -57,6 +57,12 @@ config CONSOLE_UART_BAUDRATE
     default 74880
     range 1200 4000000
 
+config CONSOLE_UART_SWAP_IO
+    bool "Swap UART0 I/O pins"
+    default n
+    help
+        Enable this option, UART0's I/O pins are swaped: TXD <-> RTS, RTX <-> CTS.
+
 endmenu
 
 menu WIFI