Re: [PATCH 2/3] ARM: OMAP2+: Add new bindings for OMAP

[Rajendra Nayak <rnayak@ti.com>]

On Wednesday 21 August 2013 01:15 PM, Tony Lindgren wrote:
> * Rajendra Nayak <rnayak@ti.com> [130820 00:41]:
>> On OMAP we have co-processor IPs, memory controllers,
>> GPIOs which control regulators and power switches to
>> PMIC, and SoC internal Bus IPs, some or most of which
>> should either not be reset or idled or both. Have a
>> way to pass this information from DT.
>> (In some cases there are erratas which prevent an IPs
>> from being reset)
>>
>> Also update omap_hwmod to extract this from DT.
>>
>> Signed-off-by: Rajendra Nayak <rnayak@ti.com>
>> ---
>>  .../devicetree/bindings/arm/omap/omap.txt          |    3 ++-
>>  arch/arm/mach-omap2/omap_hwmod.c                   |   22 +++++++++++++-------
>>  2 files changed, 17 insertions(+), 8 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/omap/omap.txt b/Documentation/devicetree/bindings/arm/omap/omap.txt
>> index 6d498c7..a08647e 100644
>> --- a/Documentation/devicetree/bindings/arm/omap/omap.txt
>> +++ b/Documentation/devicetree/bindings/arm/omap/omap.txt
>> @@ -21,7 +21,8 @@ Required properties:
>>  Optional properties:
>>  - ti,no_idle_on_suspend: When present, it prevents the PM to idle the module
>>    during suspend.
>> -
>> +- ti,no-reset: When present, the module should not be reset
>> +- ti,no-idle: When present, the module should not be idled
> 
> This naming is a bit confusing as people may think that the
> hardware has no reset support or no idle support. Let's try
> to make this to describe the hardware a bit more instead.
> 
> Then ideally we'd not map individual bits of data to properties,
> but describe few basic types of hardware instead and build
> lists of things instead of tagging things. Or maybe we
> can get this data from the bus hierarchy instead?

Yeah, I thought if I could do this without any new bindings.
For instance, never reset or idle something which is a "cpu" or an
"interrupt-controller" or a "memory-controller" or a "bus".
For some like memory-controllers though there are no bindings which
describe them as memory-controllers.

> 
> If these options don't work, and the choice may be board
> specific, then how about ti,skip-reset-on-init, and
> ti,skip-idle-on-init?

This looks fine too.

> 
> Regards,
> 
> Tony
>