[U-Boot] [PATCH v3 6/6] arm: mvf600: Add basic support for Vybrid MVF600TWR board

[Wang Huan-B18965]

Hi, Benoit,

> On Wednesday, May 22, 2013 10:23:12 AM, Wang Huan-B18965 wrote:
> 
> [...]
> 
> > > > +
> > > > +#define ENET_PAD_CTRL	(PAD_CTL_PUS_47K_UP | PAD_CTL_SPEED_HIGH
> > > | \
> > > > +			PAD_CTL_DSE_50ohm | PAD_CTL_OBE_IBE_ENABLE)
> > > > +
> > > > +#define DDR_PAD_CTRL	PAD_CTL_DSE_25ohm
> > >
> > > MUX_PAD_CTRL() could be added to the 4 pad control definitions
> above
> > > in order to avoid repeating it everywhere below. But using
> > > MUX_PAD_CTRL() relies on the fact that the pad control values in
> > > mvf_pins.h are all 0 (which is the case, but this is dangerous if
> > > this is changed later), so a better approach could be to use
> NEW_PAD_CTRL(), e.g.:
> > >         NEW_PAD_CTRL(MVF600_PAD_DDR_A15__DDR_A_15, DDR_PAD_CTRL),
> > > instead of:
> > >         MVF600_PAD_DDR_A15__DDR_A_15 | MUX_PAD_CTRL(DDR_PAD_CTRL),
> > >
> > > > +
> > [Alison Wang] I have a question about using NEW_PAD_CTRL(). If
> > NEW_PAD_CTRL() is used, should the pad control values for
> > MVF600_PAD_DDR_A15__DDR_A_15 in mvf_pins.h be the same as
> > DDR_PAD_CTRL? I saw you didn't use the same value on other platforms,
> > how do you define it?
> 
> No, you don't have to change mvf_pins.h. That's what NEW_PAD_CTRL() is
> useful
> for: You can have any pad control value defined in mvf_pins.h, and a
> board can override the pad control values when using definitions from
> mvf_pins.h, without having to modify mvf_pins.h.
> 
> E.g.:
> ---
> mvf_pins.h:
> MVF600_PAD_PTA6__RMII0_CLKIN = IOMUX_PAD(0x0, 0x0, 2, 0x0, 0,
> PAD_CTRL1),
> 
> mvf600twr.c:
> NEW_PAD_CTRL(MVF600_PAD_PTA6__RMII0_CLKIN, PAD_CTRL2),
> ---
> would have the same effect as a theoretical:
> ---
> mvf_pins.h:
> MVF600_PAD_PTA6__RMII0_CLKIN = IOMUX_PAD(0x0, 0x0, 2, 0x0, 0,
> PAD_CTRL2),
> 
> mvf600twr.c:
> MVF600_PAD_PTA6__RMII0_CLKIN,
> ---
> 
> But if you think that the pad control values that you have defined in
> mvf600twr.c are not specific to this board and should be used as the
> default pad control values for all boards based on the MVF600, then you
> should move those definitions to mvf_pins.h, and use them there, which
> means that you will no longer need MUX_PAD_CTRL() or NEW_PAD_CTRL() in
> mvf600twr.c:
> ---
> mvf_pins.h:
> #define MVF600_DDR_PAD_CTRL	PAD_CTL_DSE_25ohm
> ...
> MVF600_PAD_DDR_A15__DDR_A_15 = IOMUX_PAD(0x0220, 0x0220, 0, 0x0000, 0,
>                                          MVF600_DDR_PAD_CTRL),
> 
> mvf600twr.c:
> MVF600_PAD_DDR_A15__DDR_A_15,
[Alison Wang] I see. Thanks.

Best Regards,
Alison Wang