soc/intel/skylake: Support PCH UART 0 and 1 for console

The current PCH UART support for console is limited to UART2.

This change adds support for specifying UART0 or UART1 to be
used instead by changing CONFIG_UART_FOR_CONSOLE in the board
level Kconfig.  The default is still 2.

This is tested with a board that uses UART0 for debug output.

Change-Id: I91323ed3298f9b2558764aa4b54173833c021a7b
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/26140
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 27 insertions, 8 deletions

diff --git a/src/soc/intel/skylake/uart.c b/src/soc/intel/skylake/uart.c
index 6f3c21e586..1b4e96eb60 100644
--- a/src/soc/intel/skylake/uart.c
+++ b/src/soc/intel/skylake/uart.c
@@ -31,10 +31,20 @@
 #define PCR_SERIAL_IO_GPPRVRW7		0x618
 #define PCR_SIO_PCH_LEGACY_UART(idx)	(1 << (idx))
 
-/* UART2 pad configuration. Support RXD and TXD for now. */
-static const struct pad_config uart2_pads[] = {
-/* UART2_RXD */		PAD_CFG_NF(GPP_C20, NONE, DEEP, NF1),
-/* UART2_TXD */		PAD_CFG_NF(GPP_C21, NONE, DEEP, NF1),
+/* UART pad configuration. Support RXD and TXD for now. */
+static const struct pad_config uart_pads[][2] = {
+	{
+		PAD_CFG_NF(GPP_C8, NONE, DEEP, NF1), /* UART0_RXD */
+		PAD_CFG_NF(GPP_C9, NONE, DEEP, NF1), /* UART0_TXD */
+	},
+	{
+		PAD_CFG_NF(GPP_C12, NONE, DEEP, NF1), /* UART1_RXD */
+		PAD_CFG_NF(GPP_C13, NONE, DEEP, NF1), /* UART1_TXD */
+	},
+	{
+		PAD_CFG_NF(GPP_C20, NONE, DEEP, NF1), /* UART2_RXD */
+		PAD_CFG_NF(GPP_C21, NONE, DEEP, NF1), /* UART2_TXD */
+	}
 };
 
 #if IS_ENABLED(CONFIG_DRIVERS_UART_8250MEM)
@@ -50,9 +60,9 @@ void pch_uart_init(void)
 {
 	uintptr_t base = uart_platform_base(CONFIG_UART_FOR_CONSOLE);
 
-	uart_common_init(PCH_DEV_UART2, base);
+	uart_common_init(pch_uart_get_debug_controller(), base);
 
-	/* Put UART2 in byte access mode for 16550 compatibility */
+	/* Put UART in byte access mode for 16550 compatibility */
 	if (!IS_ENABLED(CONFIG_DRIVERS_UART_8250MEM_32)) {
 		pcr_write32(PID_SERIALIO, PCR_SERIAL_IO_GPPRVRW7,
 			PCR_SIO_PCH_LEGACY_UART(CONFIG_UART_FOR_CONSOLE));
@@ -64,7 +74,8 @@ void pch_uart_init(void)
 		lpss_clk_read(base);
 	}
 
-	gpio_configure_pads(uart2_pads, ARRAY_SIZE(uart2_pads));
+	gpio_configure_pads(uart_pads[CONFIG_UART_FOR_CONSOLE],
+			    ARRAY_SIZE(uart_pads[CONFIG_UART_FOR_CONSOLE]));
 }
 
 #if !ENV_SMM
@@ -96,5 +107,13 @@ bool pch_uart_init_debug_controller_on_resume(void)
 
 device_t pch_uart_get_debug_controller(void)
 {
-	return PCH_DEV_UART2;
+	switch (CONFIG_UART_FOR_CONSOLE) {
+	case 0:
+		return PCH_DEV_UART0;
+	case 1:
+		return PCH_DEV_UART1;
+	case 2:
+	default:
+		return PCH_DEV_UART2;
+	}
 }