[PATCH linux] arm: aspeed: zaius: Disable LPC reset for UART1

[Xo Wang]

Currently, UART1 on Zaius BMC is unusable until brought out of reset by
powering the host on. In this reset state, ttyS0 can still be opened
and UART1 silently drops bytes, which is not obviously expected
behavior.

Signed-off-by: Xo Wang <xow at google.com
---
 arch/arm/mach-aspeed/aspeed.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/mach-aspeed/aspeed.c b/arch/arm/mach-aspeed/aspeed.c
index 4bd3680d742d..9f06191f1630 100644
--- a/arch/arm/mach-aspeed/aspeed.c
+++ b/arch/arm/mach-aspeed/aspeed.c
@@ -185,6 +185,10 @@ static void __init do_zaius_setup(void)
 
 	/* Set SPI1 CE0 decoding window to 0x30000000 */
 	writel(0x68600000, AST_IO(AST_BASE_SPI | 0x30));
+
+	/* Disable LPC reset for UART1 */
+	reg = readl(AST_IO(AST_BASE_LPC | 0x98));
+	writel(reg & ~BIT(4), AST_IO(AST_BASE_LPC | 0x98));
 }
 
 static void __init do_witherspoon_setup(void)
-- 
2.11.0.483.g087da7b7c-goog