[U-Boot] [PATCH 3/3] x86: fsp: Disable legacy internal UART if necessary

[Stefan Roese]

The FSP enables the BayTrail internal UART (again). Boards that don't use
this UART but an external one instead (e.g. provided by a Super IO chip)
need to disable this internal UART. So that the one from the Super IO
chip can be used. This patch adds the necessary code, to disable the
internal legacy UART if the Winbond Super IO chip is enabled.

Signed-off-by: Stefan Roese <sr at denx.de>
Cc: Bin Meng <bmeng.cn at gmail.com>
Cc: Simon Glass <sjg at chromium.org>
---
 arch/x86/lib/fsp/fsp_support.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/x86/lib/fsp/fsp_support.c b/arch/x86/lib/fsp/fsp_support.c
index 875c96a..8114b81 100644
--- a/arch/x86/lib/fsp/fsp_support.c
+++ b/arch/x86/lib/fsp/fsp_support.c
@@ -89,6 +89,13 @@ struct fsp_header *__attribute__((optimize("O0"))) find_fsp_header(void)
 
 void fsp_continue(u32 status, void *hob_list)
 {
+	/*
+	 * The FSP enables the BayTrail internal legacy UART (again).
+	 * Disable it again, so that the Winbond one can be used.
+	 */
+	if (IS_ENABLED(CONFIG_WINBOND_W83627))
+		disable_internal_uart();
+
 	post_code(POST_MRC);
 
 	assert(status == 0);
@@ -114,6 +121,13 @@ void fsp_init(u32 stack_top, u32 boot_mode, void *nvs_buf)
 	setup_early_uart();
 #endif
 
+	/*
+	 * To use the Winbond legacy UART (COM1), the BayTrail internal
+	 * legacy UART needs to get disabled first.
+	 */
+	if (IS_ENABLED(CONFIG_WINBOND_W83627))
+		disable_internal_uart();
+
 	fsp_hdr = find_fsp_header();
 	if (fsp_hdr == NULL) {
 		/* No valid FSP info header was found */
-- 
2.6.5