driver/uart: Introduce a way for mainboard to override the baudrate

The rationale is to allow the mainboard to override the default
baudrate for instance by sampling GPIOs at boot.

A new configuration option is available for mainboards to select
this behaviour. It will then have to define the function
get_uart_baudrate to return the computed baudrate.

Change-Id: I970ee788bf90b9e1a8c6ccdc5eee8029d9af0ecc
Signed-off-by: Julien Viard de Galbert <jviarddegalbert@online.net>
Reviewed-on: https://review.coreboot.org/23713
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/soc/samsung/exynos5420/uart.c b/src/soc/samsung/exynos5420/uart.c
index a38be07d13..146151ee5b 100644
--- a/src/soc/samsung/exynos5420/uart.c
+++ b/src/soc/samsung/exynos5420/uart.c
@@ -61,7 +61,7 @@ static void serial_setbrg_dev(struct s5p_uart *uart)
 
 	// All UARTs share the same clock.
 	uclk = clock_get_periph_rate(PERIPH_ID_UART3);
-	val = uclk / CONFIG_TTYS0_BAUD;
+	val = uclk / get_uart_baudrate();
 
 	write32(&uart->ubrdiv, val / 16 - 1);
 
@@ -182,7 +182,7 @@ void uart_fill_lb(void *data)
 	struct lb_serial serial;
 	serial.type = LB_SERIAL_TYPE_MEMORY_MAPPED;
 	serial.baseaddr = uart_platform_base(CONFIG_UART_FOR_CONSOLE);
-	serial.baud = CONFIG_TTYS0_BAUD;
+	serial.baud = get_uart_baudrate();
 	serial.regwidth = 4;
 	serial.input_hertz = uart_platform_refclk();
 	serial.uart_pci_addr = 0;