Subject: [PATCH v3] OMAP2+: UART: Add mechanism to probe uart pins and configure rx wakeup

From: [email-masked] (Tony Lindgren)
Date: Tue, 5 Jun 2012 04:08:19 -0700

* Kevin Hilman <[email-masked]> [120523 16:15]:
> "Govindraj.R" <[email-masked]> writes:
> 
> > From: "Govindraj.R" <[email-masked]>
> >
> > The commit (bce492c0  ARM: OMAP2+: UART: Fix incorrect population of
> > default uart pads) removed default uart pads that where getting populated
> > and which was making rx pin wakeup capable. If uart pads were used in
> > different mode by any other module then it would fail since the default
> > pads took over all the uart pins forcefully. With removal of default pads
> > the rx_pad wakeup for console uart while waking up from off mode is broken.
> >
> > Utilise the mux api available to probe the availability of mux pins
> > in uart mode and probe for availability of uart pin in mux mode0
> > if uart is available as uart pin itself then configure rx pin
> > as wakeup capable.
> >
> > This patch itself doesn't cater to all boards. Boards using uart rx wakeup
> > mechanism should ensure the usage of omap_serial_init_port by configuring
> > required uart ports and pass necessary mux data, till then this probing of
> > uart pins can cater to enabling of rx pad wakeup to most of the boards.
> >
> > This patch can also throw some boot warning from _omap_mux_get_by_name
> > if pin is requested for availability is not present while dynamically probing
> > the uart pins availability such boot warnings can be addressed only when board
> > files are patched with omap_serial_init_port calls passing the right pads
> > needed for a given port.
> >
> > Discussion Threads for reference:
> > http://www.spinics.net/lists/linux-omap/msg69859.html
> > http://www.spinics.net/lists/linux-omap/msg68659.html
> >
> > Cc: Felipe Balbi <[email-masked]>
> > Cc: Kevin Hilman <[email-masked]>
> > Cc: Russ Dill <[email-masked]>
> > Cc: Tony Lindgren <[email-masked]>
> > Cc: Paul Walmsley <[email-masked]>
> > Cc: Ameya Palande <[email-masked]>
> > Signed-off-by: Govindraj.R <[email-masked]>
> 
> Tony, it's up to you if you're OK with this mux interface, but I can at
> least confirm that this gets runtime PM + UART wakeups working again on
> the boards I tried: 3530/Overo, 3430/n900, 3530/OMAP3EVM.

OK good to hear. Patch looks good to me, applying into fixes branch.

Regards,

Tony