diff options
| author | Jonathon Hall <jonathon.hall@puri.sm> | 2022-10-18 16:33:27 -0400 |
|---|---|---|
| committer | Felix Held <felix-coreboot@felixheld.de> | 2022-10-20 14:50:15 +0000 |
| commit | aeb8b3d4d641565ed8e92efced509483be9cdfab (patch) | |
| tree | 3a21b303ed695251fae569e3e5194265ca50f5f9 | |
| parent | f5575315fd628131adf1c237fd4a99996abfae59 (diff) | |
purism/librem_cnl: Add Kconfig to enable Mini UART
Librem Mini has a UART (accessible with soldering), which is very
useful for work on coreboot. It can be used for coreboot/SeaBIOS/Linux
boot logs, or as a general purpose UART.
Change-Id: I38ad5f19da6af5ed286ad3583f34b824a3660916
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68551
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
3 files changed, 30 insertions, 0 deletions
diff --git a/src/mainboard/purism/librem_cnl/Kconfig b/src/mainboard/purism/librem_cnl/Kconfig index 39b0883a53..f0fd6a85f0 100644 --- a/src/mainboard/purism/librem_cnl/Kconfig +++ b/src/mainboard/purism/librem_cnl/Kconfig @@ -60,3 +60,19 @@ config NO_POST default y endif + +config ENABLE_EC_UART1 + bool "Enable EC UART1" + depends on BOARD_PURISM_LIBREM_MINI || BOARD_PURISM_LIBREM_MINI_V2 + default n + select DRIVERS_UART_8250IO + help + Enable UART1 on the EC. + + This UART can be used for boot logging by coreboot, SeaBIOS, or + Linux. It also works as a general-purpose UART. + + Soldering is required to access these signals. Locate the pads for + U81 on the bottom of the board near the front edge; the IC is not + populated. TX is pin 14, RX is pin 19. The signals are 3.3V (do NOT + connect directly to an RS-232 serial port). diff --git a/src/mainboard/purism/librem_cnl/variants/librem_mini/Makefile.inc b/src/mainboard/purism/librem_cnl/variants/librem_mini/Makefile.inc index 20ff43819f..59020ef001 100644 --- a/src/mainboard/purism/librem_cnl/variants/librem_mini/Makefile.inc +++ b/src/mainboard/purism/librem_cnl/variants/librem_mini/Makefile.inc @@ -2,3 +2,4 @@ all-y += die.c smm-y += die.c +bootblock-$(CONFIG_ENABLE_EC_UART1) += com_init.c diff --git a/src/mainboard/purism/librem_cnl/variants/librem_mini/com_init.c b/src/mainboard/purism/librem_cnl/variants/librem_mini/com_init.c new file mode 100644 index 0000000000..6d0f79f843 --- /dev/null +++ b/src/mainboard/purism/librem_cnl/variants/librem_mini/com_init.c @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include <bootblock_common.h> +#include <device/pnp_ops.h> + +#define SERIAL_DEV PNP_DEV(0x6E, 1) /* ITE8528 UART1 */ + +void bootblock_mainboard_early_init(void) +{ + /* Enable the serial port inside the EC */ + pnp_set_logical_device(SERIAL_DEV); + pnp_set_enable(SERIAL_DEV, 1); +} |