[U-Boot] [PATCH] serial: add environment control for SERIAL_MULTI

[Marek Vasut <marex@denx.de>]

Dear Allen Martin,

> Add a new special environment variable "serial" that allows selection
> of serial device when CONFIG_SERIAL_MULTI is defined.  This replaces
> the existing calls to serial_assign() from cmd_nvedit.c and iomux.c
> that were not doing anything.
> 
> Signed-off-by: Allen Martin <amartin@nvidia.com>
> ---
>  common/cmd_nvedit.c             |    7 ++++++-
>  common/iomux.c                  |   10 ----------
>  doc/driver-model/UDM-serial.txt |    5 +++--
>  3 files changed, 9 insertions(+), 13 deletions(-)
> 
> diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c
> index 1f9c674..d1ee07d 100644
> --- a/common/cmd_nvedit.c
> +++ b/common/cmd_nvedit.c
> @@ -238,11 +238,16 @@ int env_check_apply(const char *name, const char
> *oldval, /* Try assigning specified device */
>  		if (console_assign(console, newval) < 0)
>  			return 1;
> +#endif /* CONFIG_CONSOLE_MUX */
> +	}
> 
> +#ifdef CONFIG_SERIAL_MULTI

Drop this, it's default. There's no CONFIG_SERIAL_MULTI in the tree at all 
anymore.

> +	/* Check for serial redirection */
> +	if (strcmp(name, "serial") == 0) {
>  		if (serial_assign(newval) < 0)
>  			return 1;
> -#endif /* CONFIG_CONSOLE_MUX */
>  	}
> +#endif /* CONFIG_SERIAL_MULTI */
> 
>  	/*
>  	 * Some variables like "ethaddr" and "serial#" can be set only once and
> diff --git a/common/iomux.c b/common/iomux.c
> index dbc2312..6a75704 100644
> --- a/common/iomux.c
> +++ b/common/iomux.c
> @@ -135,16 +135,6 @@ int iomux_doenv(const int console, const char *arg)
>  		 */
>  		if (console_assign(console, start[j]) < 0)
>  			continue;
> -		/*
> -		 * This was taken from common/cmd_nvedit.c.
> -		 * This will never work because serial_assign() returns
> -		 * 1 upon error, not -1.
> -		 * This would almost always return an error anyway because
> -		 * serial_assign() expects the name of a serial device, like
> -		 * serial_smc, but the user generally only wants to set serial.
> -		 */
> -		if (serial_assign(start[j]) < 0)
> -			continue;
>  		cons_set[cs_idx++] = dev;
>  	}
>  	free(console_args);
> diff --git a/doc/driver-model/UDM-serial.txt
> b/doc/driver-model/UDM-serial.txt index 9feb2e5..66f3e6b 100644
> --- a/doc/driver-model/UDM-serial.txt
> +++ b/doc/driver-model/UDM-serial.txt
> @@ -26,8 +26,9 @@ and serial_setbrg() are often called from
> platform-dependent places. It's important to consider current
> implementation of CONFIG_SERIAL_MULTI though. This resides in
> common/serial.c and behaves as a multiplexer for serial ports. This, by
> calling serial_assign(), allows user to switch I/O from one serial port
> -to another. Though the environmental variables "stdin", "stdout",
> "stderr" -remain set to "serial".
> +to another. The environment variable "serial" is used to select which of
> the +serial ports is the currently active port.  The environmental
> variables +"stdin", "stdout", "stderr" remain set to "serial".
> 
>  These variables are managed by the IOMUX. This resides in common/iomux.c
> and manages all console input/output from U-Boot. For serial port, only
> one IOMUX is

Best regards,
Marek Vasut