diff --git a/src/soc/intel/skylake/bootblock/uart.c b/src/soc/intel/skylake/bootblock/uart.c index b7ab241f77..f6e7e13b8e 100644 --- a/src/soc/intel/skylake/bootblock/uart.c +++ b/src/soc/intel/skylake/bootblock/uart.c @@ -27,9 +27,7 @@ /* Serial IO UART controller legacy mode */ #define PCR_SERIAL_IO_GPPRVRW7 0x618 -#define PCR_SIO_PCH_LEGACY_UART0 (1 << 0) -#define PCR_SIO_PCH_LEGACY_UART1 (1 << 1) -#define PCR_SIO_PCH_LEGACY_UART2 (1 << 2) +#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[] = { @@ -44,9 +42,16 @@ void pch_uart_init(void) uart_common_init(PCH_DEV_UART2, base); /* Put UART2 in byte access mode for 16550 compatibility */ - if (!IS_ENABLED(CONFIG_DRIVERS_UART_8250MEM_32)) + if (!IS_ENABLED(CONFIG_DRIVERS_UART_8250MEM_32)) { pcr_write32(PID_SERIALIO, PCR_SERIAL_IO_GPPRVRW7, - PCR_SIO_PCH_LEGACY_UART2); + PCR_SIO_PCH_LEGACY_UART(CONFIG_UART_FOR_CONSOLE)); + + /* + * Dummy read after setting any of GPPRVRW7. + * Required for UART 16550 8-bit Legacy mode to become active + */ + lpss_clk_read(base); + } gpio_configure_pads(uart2_pads, ARRAY_SIZE(uart2_pads)); }