[U-Boot] [PATCH] mx6: Add IOMUX_CONFIG_SION flag to all GPIO pins

Otavio Salvador otavio at ossystems.com.br
Tue Oct 1 15:08:51 CEST 2013


On Tue, Oct 1, 2013 at 9:43 AM, Marek Vasut <marex at denx.de> wrote:
> Dear Otavio Salvador,
>
>> On Tue, Oct 1, 2013 at 5:33 AM, Stefano Babic <sbabic at denx.de> wrote:
>> > Hi Otavio,
>> >
>> > On 30/09/2013 00:15, Otavio Salvador wrote:
>> >> The IOMUX_CONFIG_SION allows for reading PAD value from PSR register.
>> >>
>> >> The following quote from the datasheet:
>> >>
>> >> ,----
>> >>
>> >> | ...
>> >> | 28.4.2.2 GPIO Write Mode
>> >> | The programming sequence for driving output signals should be as
>> >> | follows: 1. Configure IOMUX to select GPIO mode (Via IOMUXC), also
>> >> | enable SION if need to read loopback pad value through PSR
>> >> | 2. Configure GPIO direction register to output (GPIO_GDIR[GDIR] set to
>> >> | 1b). 3. Write value to data register (GPIO_DR).
>> >> | ...
>> >>
>> >> `----
>> >>
>> >> This fixes the gpio_get_value to properly work when a GPIO is set for
>> >> output and has no conflicts.
>> >>
>> >> Thanks for Benoît Thébaudeau <benoit.thebaudeau at advansee.com>, Fabio
>> >> Estevam <fabio.estevam at freescale.com> and Eric Bénard
>> >> <eric at eukrea.com> for helping to properly trace this down.
>> >>
>> >> Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
>> >> ---
>> >
>> > I come later in the discussion, but I see you all have found the
>> > solution ;-).
>> >
>> > I suggest you add in the commit message that this patch is only for
>> > i.MX6 (if you do not plan to extend it to the other i.MXes...), so that
>> > we can track that the same must be done also for the other SOCs.
>>
>> I think this is clear from the commit prefix.
>
> The commit message should be ARM: mx6: or such btw.
>
> It'd be nice to fix it up for MX5 as well so we're consistent.

Benoit expressed some doubt if it can be assumed to behave the same
for all i.MX that's why I didn't apply it for all. I cannot look at
this, at this moment, so I prefer to not change it without checking
the datasheet for it.


-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854            Mobile: +1 (347) 903-9750


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