[PATCH 1/4] ARM: OMAP3 PM: Fix IO Daisychain sequence

Kevin Hilman khilman at ti.com
Tue Oct 4 16:47:48 EDT 2011

Hi Vishwa,

Vishwanath BS <vishwanath.bs at ti.com> writes:

> As per OMAP3630 TRM Section, the right sequence for enabling IO Daisy
> chain is "The I/O wake-up scheme is enabled by triggering the I/O daisy chain
> control (Wu clock) by programming a dedicated register
> (PRCM.PM_WKEN_WKUP[16] EN_IO_CHAIN) in the PRCM module.Software must wait for
> the I/O daisy chain to complete before it transitions the PER domain to a
> nonfunctional state. This is done by polling a dedicated status bit in the PRCM
> module (PRCM.PM_WKST_WKUP[16] ST_IO_CHAIN). This status bit must be cleared by
> software when the bit is read to  1".
> The original code was polling on a wrong register which is fixed in this patch.
> Also omap3_enable_io_chain is made non static as it's going to be used in
> subsequent patches.
> Signed-off-by: Vishwanath BS <vishwanath.bs at ti.com>

A fix for this was posted[1] by Mohan V (added to Cc) back in June.  It
recieved a few minor comments but an updated version was never posted.

Maybe you can ping Mohan or update that version fixing the comments
mentioned in that thread.



[1] http://marc.info/?l=linux-omap&w=2&r=1&s=%27Mohan+V%27&q=b

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