[U-Boot] [PATCH 62/71] serial: spl: Implement empty functions for SPL

[Marek Vasut <marex@denx.de>]

Dear Tom Rini,

> On Mon, Sep 17, 2012 at 01:21:27AM +0200, Marek Vasut wrote:
> > Implement empty serial_* functions for SPL without serial
> > support enabled. This is imperative to haave once serial
> > multi is enabled unconditionally.
> > 
> > Signed-off-by: Marek Vasut <marex@denx.de>
> > Cc: Marek Vasut <marek.vasut@gmail.com>
> > Cc: Tom Rini <trini@ti.com>
> > ---
> > 
> >  common/serial.c |   12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> > 
> > diff --git a/common/serial.c b/common/serial.c
> > index 631af65..cef4ba8 100644
> > --- a/common/serial.c
> > +++ b/common/serial.c
> > @@ -27,6 +27,16 @@
> > 
> >  #include <post.h>
> >  #include <linux/compiler.h>
> > 
> > +/* Implement prototypes for SPL without serial support */
> > +#if defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_SERIAL_SUPPORT)
> > +int serial_init(void) { return 0; }
> > +void serial_setbrg(void) {}
> > +int serial_getc(void) { return 0; }
> > +int serial_tstc(void) { return 0; }
> > +void serial_putc(const char c) {}
> > +void serial_puts(const char *s) {}
> 
> This isn't quite right.  We need to allow for:
> - No output SPL, strings collected (so #defined to do{} while (0))

Which is not type-checked and will drag in bugs.

> - puts + printf SPL (CONFIG_SPL_SERIAL_SUPPORT +
>   CONFIG_SPL_LIBCOMMON_SUPPORT)
> - puts only SPL (CONFIG_SPL_SERIAL_SUPPORT + #define puts
>   serial_puts/putc).
> 
> I'm not asking you to do that, but you will have to adapt to it once
> Jose is done with it.  What that means, off the top of my head, is we
> can just drop this patch as in the first and last case serial.o will be
> garbage-collected (or not built) and in the middle case, this will be
> fully used.

I can't drop this patch as it will break all of SPL when CONFIG_SERIAL_MULTI is 
unconditionally enabled.

Best regards,
Marek Vasut