[U-Boot] [PATCH] Tegra114: pinmux: Fix bad CAM_MCLK func 3 table entry

[Tom Warren]

On Wed, Mar 13, 2013 at 3:34 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 03/13/2013 04:10 PM, Tom Warren wrote:
>> This caused CAM_MCLK's pinmux reg to be locked out, since the
>> table parsing code couldn't find a matching entry for VI_ALT3
>> and wrote garbage to the register.
>
>> diff --git a/arch/arm/cpu/tegra114-common/pinmux.c b/arch/arm/cpu/tegra114-common/pinmux.c
>
>> @@ -239,7 +239,7 @@ const struct tegra_pingroup_desc tegra_soc_pingroups[PINGRP_COUNT] = {
>
>> -     PINI(CAM_MCLK,    CAM,     VI,         VI_ALT1,    VI_ALT2, RSVD4),
>> +     PINI(CAM_MCLK,    CAM,     VI,         VI_ALT1,    VI_ALT3, RSVD4),
>
> This doesn't seem right; the "alt" settings should be assigned in order
> non-alt, alt1, alt2, alt3.

According to the TRM, CAM_MCLK takes the following 4 possible mux settings:

0 = VI
1 = VI_ALT1
2 = VI_ALT3
3 = RSVD3

There is no VI_ALT2 in the Tegra114 TRM. There was in the T30 TRM.

>
> You say, "the table parsing code couldn't find a matching entry for
> VI_ALT3". What was looking for that entry?
The pinmux table entry in
board/nvidia/dalmore/pinmux-config-dalmore.h, table
tegra114_pinmux_common[], VI_PINMUX(CAM_MCLK, VI_ALT3, ...), which is
parsed by pinmux_config_pingroup in pinmux.c.

>
> Also, shouldn't the pinmux driver be fixed not to write garbage to a
> register, but instead return an error, if it can't find the table entry
> it's looking for?
There's an assert if the mux isn't found - I thought that would handle
it, but it appears that it will only if DEBUG is enabled. I'll add
more error checking to the code - I have a pinmux.c/pinmux.h update
coming for other problems I found while chasing this down.

Tom