[U-Boot] [PATCH 01/31] iMX28: Initial support for iMX28 CPU

Stefano Babic sbabic at denx.de
Fri Sep 9 12:29:01 CEST 2011


On 09/09/2011 12:12 PM, Marek Vasut wrote:

>>
>> Another general remark here: we tend to have the same structure and the
>> same files for all IMX SOC. This means that all IMX SOC have a
>> imx-regs.h that contain the required register definitions (really a
>> subset what we have in kernel). Is it really necessary to split the
>> definitions in several small files ?
> 
> Just like Heiko said ... it'd produce terribly big and messy file. I'd prefer to 
> avoid that.

This is ok, and it is ok also that your imx-regs.h file contains only
the reg-specific include files. What is not ok, is that you do not use
imx-regs.h and you still includes each separate file. And as I see, they
must be included in a specific order.

This order must be defined only in imx-regs.h, as you have already done
and then each driver/board requires to include only imx-regs.h, without
having to care of the single files.

> Honestly, I need to check if the file is used at all. We replaced the original 
> driver with pl011 driver.

Ok

>> Again, regarding file splitting for register. If you prefer to have
>> several files, I think it is better that imx-regs.h include them. Then
>> we have still a common header imx-regs.h that contains all needed
>> register definitions. This is a better interface for a board maintainer.
> 
> Won't it make the compiler slower at compile time if it has to go through all of 
> the included files instead of a subset ?

Well, I do not know if on our Intel-PC this makes a so noticeable
difference ;-)

What I remark here, it is to have a clear and identical interface among
the several SOCs. This is not only easier for board developers, but also
removes some nasty #ifdef CONFIG_MX from the drivers.

>>
>> To understand: does a reset mean on the i.MX28 a power off ? Do you turn
>> off the power ? If this is the case, some features are not possible (as
>> PRAM, for example) on this SOC.
> 
> This should just reset the chip. No poweroff.

Ok - thanks for clarification.

> 
> I'll probably wait for someone to clearly say how this should be to avoid 
> reworking it for the fourth time.

Right.

Best regards,
Stefano Babic

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