[U-Boot] [PATCH] env: ti: boot: Use ttyS2 instead of ttyO2

[Andrew F. Davis <afd@ti.com>]

On 7/12/19 1:38 PM, Sam Protsenko wrote:
> ttyO2 console enables legacy CONFIG_SERIAL_OMAP driver in kernel.
> Nowadays it's preferred to use the generic CONFIG_SERIAL_8250_OMAP
> driver, which being enabled via ttyS2 console. Both drivers are enabled
> in multi_v7_defconfig and in omap2plus_defconfig, for compatibility
> reasons. Let's switch to ttyS2 console, to be sure that standard 8250
> serial driver is used.
> 
> Similar behavior can be also achieved by enabling
> CONFIG_SERIAL_8250_OMAP_TTYO_FIXUP option in kernel, but it's better not
> to rely on that, as it can be disabled or removed after transitional
> period.
> 
> Right now on DRA7/AM57x platforms the 8250-omap driver is being probed
> first, and omap-serial driver is only probed if the first one failed.
> It can be seen from uart3 definition in arch/arm/boot/dts/dra7-l4.dtsi:
> 
>     compatible = "ti,dra742-uart", "ti,omap4-uart";
> 
> So the kernel already uses 8250 driver. This change basically allows
> kernel developers to throw away the omap-serial driver and associated
> compatibility options. Similar discussions [1,2] have started several
> years ago, so it should be safe to do that now.
> 
> [1] https://patchwork.kernel.org/patch/6198471/
> [2] http://processors.wiki.ti.com/index.php/Sitara_Linux_UART_-_Switching_to_8250_Driver
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> ---
> Changes in v2:
>   - use ttyS also in AM57x EVM and in DRA7xx EVM configs
> 
>  include/configs/am57xx_evm.h  | 2 +-
>  include/configs/dra7xx_evm.h  | 4 ++--
>  include/environment/ti/boot.h | 2 +-
>  3 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/include/configs/am57xx_evm.h b/include/configs/am57xx_evm.h
> index 45fd21878c..e181b30564 100644
> --- a/include/configs/am57xx_evm.h
> +++ b/include/configs/am57xx_evm.h
> @@ -24,7 +24,7 @@
>  
>  #define CONFIG_SYS_BOOTM_LEN		SZ_64M
>  
> -#define CONSOLEDEV			"ttyO2"
> +#define CONSOLEDEV			"ttyS2"
>  #define CONFIG_SYS_NS16550_COM1		UART1_BASE	/* Base EVM has UART0 */
>  #define CONFIG_SYS_NS16550_COM2		UART2_BASE	/* UART2 */
>  #define CONFIG_SYS_NS16550_COM3		UART3_BASE	/* UART3 */
> diff --git a/include/configs/dra7xx_evm.h b/include/configs/dra7xx_evm.h
> index 9c8141de2e..7ec6e691c7 100644
> --- a/include/configs/dra7xx_evm.h
> +++ b/include/configs/dra7xx_evm.h
> @@ -26,9 +26,9 @@
>  #endif
>  
>  #if (CONFIG_CONS_INDEX == 1)

This CONFIG_CONS_INDEX is not enabled for this platform, meaning the
non-default console is chosen by default, it's not caused by this patch
but while you are here could you fix that up?

Just set:

#define CONSOLEDEV   "ttyS0"

and drop all the #ifdef stuff, makes things a bit more clean. (and
prevents a conflict with a patch I was going to send for the same)

Andrew

> -#define CONSOLEDEV			"ttyO0"
> +#define CONSOLEDEV			"ttyS0"
>  #elif (CONFIG_CONS_INDEX == 3)
> -#define CONSOLEDEV			"ttyO2"
> +#define CONSOLEDEV			"ttyS2"
>  #endif
>  #define CONFIG_SYS_NS16550_COM1		UART1_BASE	/* Base EVM has UART0 */
>  #define CONFIG_SYS_NS16550_COM2		UART2_BASE	/* UART2 */
> diff --git a/include/environment/ti/boot.h b/include/environment/ti/boot.h
> index 01b2981c5b..22206b9467 100644
> --- a/include/environment/ti/boot.h
> +++ b/include/environment/ti/boot.h
> @@ -10,7 +10,7 @@
>  #define __TI_BOOT_H
>  
>  #ifndef CONSOLEDEV
> -#define CONSOLEDEV "ttyO2"
> +#define CONSOLEDEV "ttyS2"
>  #endif
>  
>  #define VBMETA_PART_SIZE		(64 * 1024)
>