From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@ti.com (Kevin Hilman) Date: Tue, 04 Oct 2011 13:47:48 -0700 Subject: [PATCH 1/4] ARM: OMAP3 PM: Fix IO Daisychain sequence In-Reply-To: <1317750724-32553-2-git-send-email-vishwanath.bs@ti.com> (Vishwanath BS's message of "Tue, 4 Oct 2011 23:22:01 +0530") References: <1317750724-32553-1-git-send-email-vishwanath.bs@ti.com> <1317750724-32553-2-git-send-email-vishwanath.bs@ti.com> Message-ID: <87r52s8owb.fsf@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Vishwa, Vishwanath BS writes: > As per OMAP3630 TRM Section 3.5.7.2.2, 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 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. Thanks, Kevin [1] http://marc.info/?l=linux-omap&w=2&r=1&s=%27Mohan+V%27&q=b