gpio/omap: convert gpio irq domain to linear mapping

Currently the OMAP GPIO driver uses a legacy mapping for the GPIO IRQ
domain. This is not necessary because we do not need to assign a
specific interrupt number to the GPIO IRQ domain. Therefore, convert
the OMAP GPIO driver to use a linear mapping instead.

Please note that this also allows to simplify the logic in the OMAP
gpio_irq_handler() routine, by using irq_find_mapping() to obtain the
virtual irq number from the GPIO bank and bank index.

Reported-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
gpio/omap: warn if bank is not enabled on setting irq type

For OMAP devices, if a gpio is being used as an interrupt source but has
not been requested by calling gpio_request(), a call to request_irq()
may cause the kernel hang because the gpio bank may be disabled and
hence the register access will fail. To prevent such hangs, test for
this case and warn if this is detected.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
gpio/omap: free irq domain in probe() failure paths

Currently the IRQ domain is not freed once allocated, in the case where
omap_gpio_probe() fails. Therefore, ensure we free the domain if the
probe does fail. Furthermore, the local variable "ret" is not needed
and so remove this.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
gpio/omap: remove extra context restores in *_runtime_resume()

68942edb09f69b6e09522d1d346665eb3aadde49 (gpio/omap: fix wakeups
on level-triggered GPIOs) already restores the fallingdetect and
risingdetect contexts in *_runtime_resume(). These registers were
modified in *_runtime_suspend() to include even those configured
as level-triggered since only edge-triggered gpios can generate
wakeup events. Therefore, the old context restores of the same
registers present later in the code is not needed any more.
Remove them.

Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@ti.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
gpio/omap: optimise interrupt service routine

The OMAP GPIO interrupt service routine is checking each bit in the
GPIO interrupt status register to see which bits are set. It is not
efficient to check every bit especially if only a few bits are set.
Therefore, instead of checking every bit use the __ffs() function,
which returns the location of the first set bit, to find all the set
bits.

This optimisation was suggested-by and developed in collaboration
with Felipe Balbi.

Cc: Felipe Balbi <balbi@ti.com>

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
gpio/omap: force restore if context loss is not detectable

When booting with device-tree the function pointer for detecting context
loss is not populated. Ideally, the pm_runtime framework should be
enhanced to allow a means for reporting context/state loss and we could
avoid populating such function pointers altogether. In the interim until
a generic non-device specific solution is in place, force a restore of
the gpio bank when enabling the gpio controller.

Adds a new device-tree property for the OMAP GPIO controller to indicate
if the GPIO controller is located in a power-domain that never loses
power and hence will always maintain its logic state.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: dts: OMAP2+: Identify GPIO banks that are always powered

Add the "ti,gpio-always-on" property to the appropriate GPIO banks to
indicate which banks are always powered and will never lose logic state.

Cc: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: AM33xx: hwmod: Add missing sysc definition to wdt1 entry

This patch adds sysc definitions to the wdt1 hwmod entry, which in-turn
makes sure that sysc idle bit-fields are configured to valid state on
enable/disable callbacks.

With the recent submitted patch from Santosh Shilimkar,
"ARM: OMAP2+: hwmod: Don't call _init_mpu_rt_base if no sysc"
(commit: 4a98c2d89), it is required to add sysconf
information to each valid hwmod entry, else device will not be
come out from idle state properly and leads to below kernel
crash  -

[2.190237] Unhandled fault: external abort on non-linefetch (0x1028) at
0xf9e35034
[2.198325] Internal error: : 1028 [#1] SMP ARM
[2.203101] Modules linked in:
[2.206334] CPU: 0    Not tainted  (3.9.0-rc3-00059-gd114294#1)
[2.212679] PC is at omap_wdt_disable.clone.5+0xc/0x60
[2.218090] LR is at omap_wdt_probe+0x184/0x1fc

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Benoit Cousson <benoit.cousson@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
ARM: OMAP2+: am335x: Change the wdt1 func clk src to per_32k clk

WDT1 module can take one of the below clocks as input functional
clock -
     - On-Chip 32K RC Osc [default/reset]
     - 32K from PRCM

The On-Chip 32K RC Osc clock is not an accurate clock-source as per
the design/spec, so as a result, for example, timer which supposed
to get expired @60Sec, but will expire somewhere ~@40Sec, which is
not expected by any use-case.

The solution here is to switch the input clock-source to PRCM
generated 32K clock-source during boot-time itself.

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Benoit Cousson <benoit.cousson@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
Documentation: dt: update TI GPMC ethernet binding properties

The GPMC timing properties for device-tree have been updated
by adding a "-ns" or "-ps" suffix to indicate the units of
time the property represents. Therefore, update the timing
property names for TI GPMC ethernet binding.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Documentation: dt: update properties in TI GPMC NAND example

The GPMC timing properties for device-tree have been updated
by adding a "-ns" or "-ps" suffix to indicate the units of
time the property represents. Therefore, update the timing
property names for TI GPMC NAND example.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: dts: OMAP4: Fix ethernet IRQ for OMAP4 boards

Commit ff5c9059 (ARM: dts: OMAP3+: Correct gpio #interrupts-cells
property) updated the number of interrupt cells required for configuring
gpios as interrupts for other devices (such as ethernet controllers).
This update allowed the interrupt type (edge, level, etc) to be
configured via device-tree (as described in the
Documentation/devicetree/bindings/gpio/gpio-omap.txt).

This broke ethernet support on the OMAP4 SDP board that defines a gpio
as the ethernet IRQ because the interrupt type (level, edge, etc) was
not getting configured correctly. This board use the ks8851 ethernet
chip which has an active low interrupt. Fix this by defining the gpio
interrupt as active-low in the device-tree binding.

Please note that the OMAP4-VAR-SOM also uses the same ethernet
controller and it is expected it will have the same problem. So the
same fix is also applied to this board.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
gpio/omap: ensure gpio context is initialised

Commit a2797be (gpio/omap: force restore if context loss is not
detectable) broke gpio support for OMAP when booting with device-tree
because a restore of the gpio context being performed without ever
initialising the gpio context. In other words, the context restored was
bad.

This problem could also occur in the non device-tree case, however, it
is much less likely because when booting without device-tree we can
detect context loss via a platform specific API and so context restore
is performed less often.

Nevertheless we should ensure that the gpio context is initialised
during the probe for gpio banks that could lose their state regardless
of whether we are booting with device-tree or not.

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Merge branch 'omap-dma-for-v3.10' into omap-daily-testing
Merge branch 'omap-dmtimer-for-v3.10' into omap-daily-testing
Merge branch 'omap-dt-for-v3.10-take2' into omap-daily-testing
Merge branch 'omap-gpio-for-v3.10' into omap-daily-testing
Merge branch 'omap-gpmc-for-v3.10-take2' into omap-daily-testing
Merge branch 'omap-timer-for-v3.10' into omap-daily-testing
Merge branch 'omap-fixes-for-v3.10' into omap-daily-testing

Conflicts:
	drivers/gpio/gpio-omap.c