[U-Boot] [PATCH v4 2/6] serial: add UniPhier serial driver

[Masahiro Yamada]

Hi Marek,



On Fri, 5 Sep 2014 12:35:18 +0200
Marek Vasut <marex at denx.de> wrote:

> On Friday, September 05, 2014 at 07:50:19 AM, Masahiro Yamada wrote:
> > The driver for on-chip UART used on Panasonic UniPhier platform.
> > 
> > Signed-off-by: Masahiro Yamada <yamada.m at jp.panasonic.com>
> 
> [...]
> 
> Hi!
> 
> > +static void uniphier_serial_putc(struct uniphier_serial *port, const char
> > c) +{
> > +	if (c == '\n')
> > +		uniphier_serial_putc(port, '\r');
> 
> Just curious, but what is the concensus about inserting \r upon \n ? Shouldn't 
> this be something that the "upper layers" do consistently ? I recall seeing this 
> in some drivers and not seeing this in the others, so I wonder why this is like 
> so ...


This converts "\n" to "\r\n".

Without this conversion, CarriageReturn is not provided,
which means the cursor goes to the next line, but
column position does not change.


For example,

printf("Hello\nWorld\n");

will be displayed on (at least my) terminal emulator like this:


Hello
     World


With the conversion code, it will be displaye as follows:

Hello
World



Perhaps the behavior might depend on
which therminal emulator you are using.
(also depend on the preference
how LF and CR are handled.)



Maybe we can move  "\n -> \r\n" logic
to the upper layer and allow users to enable/disable it
with a CONFIG_ option.




Best Regards
Masahiro Yamada