[PATCHv4 1/6] ARM: OMAP3 PM: correct enable/disable of daisy io chain

[Paul Walmsley]

cc'ing Nilesh, Rajendra

Hi

On Fri, 2 Mar 2012, Tero Kristo wrote:

> From: Mohan V <mohanv at ti.com>
> 
> Currently the enabling and disabling of IO Daisy chain is not
> according to the TRM. The below steps are followed to enable/
> disable the IO chain according to the "Sec 3.5.7.2.2
> I/O Wake-Up Mechanism" in OMAP3630 Public TRM[1].
> 
> Steps to enable IO chain:
> [a] Set PM_WKEN_WKUP.EN_IO bit
> [b] Set the PM_WKEN_WKUP.EN_IO_CHAIN bit
> [c] Poll for PM_WKST_WKUP.ST_IO_CHAIN.
> [d] When ST_IO_CHAIN bit set to 1, clear PM_WKEN_WKUP.EN_IO_CHAIN

Looking at the above TRM section, it doesn't mention clearing 
PM_WKEN_WKUP.EN_IO_CHAIN at all.  This only seems to be mentioned (in a 
rather unclear way) in the OMAP4430 TRM.

Since Tero and Rajendra are reporting that this series works, I assume 
that the conclusion is that this patch description just needs to be fixed.  
Could someone confirm that this is indeed the case -- that I/O wakeups are 
expected to work when EN_IO_CHAIN/WUCLK_CTRL is 0?

Is the I/O wakeup path from the pad to the PRCM wakeup line completely 
asynchronous?


- Paul