Current OMAP4 CPUIdle driver is using omap4_mpuss_read_prev_context_state()
to check whether the MPU cluster lost context or not before calling
cpu_cluster_pm_exit().  This was initially done an optimization for
corner cases, where if the cluster low power entry fails for some
reason, the cluster context restore gets skipped.  However, since
reading the previous context is expensive (involving slow accesses to
the PRCM), it's better to avoid it and simply check the target cluster
state instead.

Moving forward, OMAP CPUidle drivers needs to be moved to drivers/idle/*
once the PRM/CM code gets moved to drivers. This patch also reduces one
dependency with platform code for idle driver movement.
Acked-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
[khilman@linaro.org: minor changelog edits]
Signed-off-by: NKevin Hilman <khilman@linaro.org>

The OMAP4 MPU subsystem power management code contains several unnecessary
shim functions for powerdomain control; remove them.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

On OMAP4+ devices, GIC register context is lost when MPUSS hits
the OSWR(Open Switch Retention). On the CPU wakeup path, ROM code
gets executed and one of the steps in it is to restore the
saved context of the GIC. The ROM Code GIC distributor restoration
is split in two parts: CPU specific register done by each CPU and
common register done by only one CPU.

Below is the abstract flow.

...............................................................
- MPUSS in OSWR state.
- CPU0 wakes up on the event(interrupt) and start executing ROM code.

[..]

- CPU0 executes "GIC Restoration:"

[...]

- CPU0 swicthes to non-secure mode and jumps to OS resume code.

[...]

- CPU0 is online in OS
- CPU0 enables the GIC distributor. GICD.Enable Non-secure = 1
- CPU0 wakes up CPU1 with clock-domain force wakeup method.
- CPU0 continues it's execution.
[..]

- CPU1 wakes up and start executing ROM code.

[..]

- CPU1 executes "GIC Restoration:"

[..]

- CPU1 swicthes to non-secure mode and jumps to OS resume code.

[...]

- CPU1 is online in OS and start executing.
[...]   -

GIC Restoration: /* Common routine for HS and GP devices */
{
       if (GICD != 1)  { /* This will be true in OSWR state */
               if (GIC_SAR_BACKUP_STATE == SAVED)
                       - CPU restores GIC distributor
               else
                       - reconfigure GIC distributor to boot values.

               GICD.Enable secure = 1
       }

       if (GIC_SAR_BACKUP_STATE == SAVED)
               - CPU restore its GIC CPU interface registers if saved.
       else
               - reconfigure its GIC CPU interface registers to boot
                       values.
}
...............................................................

So as mentioned in the flow, GICD != 1 condition decides how
the GIC registers are handled in ROM code wakeup path from
OSWR. As evident from the flow, ROM code relies on the entire
GICD register value and not specific register bits.

The assumption was valid till CortexA9 r1pX version since there
was only one banked bit to control secure and non-secure GICD.
Secure view which ROM code sees:
       bit 0 == Enable Non-secure
Non-secure view which HLOS sees:
       bit 0 == Enable secure

But GICD register has changed between CortexA9 r1pX and r2pX.
On r2pX GICD register is composed of 2 bits.
Secure view which ROM code sees:
       bit 1 == Enable Non-secure
       bit 0 == Enable secure
Non-secure view which HLOS sees:
       bit 0 == Enable Non-secure

Hence on OMAP4460(r2pX) devices, if you go through the
above flow again during CPU1 wakeup, GICD == 3 and hence
ROM code fails to understand the real wakeup power state
and reconfigures GIC distributor to boot values. This is
nasty since you loose the entire interrupt controller
context in a live system.

The ROM code fix done on next OMAP4 device (OMAP4470 - r2px) is to
check "GICD.Enable secure != 1" for GIC restoration in OSWR wakeup path.

Since ROM code can't be fixed on OMAP4460 devices, a work around
needs to be implemented. As evident from the flow, as long as
CPU1 sees GICD == 1 in it's wakeup path from OSWR, the issue
won't happen. Below is the flow with the work-around.

...............................................................
- MPUSS in OSWR state.
- CPU0 wakes up on the event(interrupt) and start executing ROM code.

[..]

- CPU0 executes "GIC Restoration:"

[..]

- CPU0 swicthes to non-secure mode and jumps to OS resume code.

[..]

- CPU0 is online in OS.
- CPU0 does GICD.Enable Non-secure = 0
- CPU0 wakes up CPU1 with clock domain force wakeup method.
- CPU0 waits for GICD.Enable Non-secure = 1
- CPU0 coninues it's execution.
[..]

- CPU1 wakes up and start executing ROM code.

[..]

- CPU1 executes "GIC Restoration:"

[..]

- CPU1 swicthes to non-secure mode and jumps to OS resume code.

[..]

- CPU1 is online in OS
- CPU1 does GICD.Enable Non-secure = 1
- CPU1 start executing
[...]
...............................................................

With this procedure, the GIC configuration done between the
CPU0 wakeup and CPU1 wakeup will not be lost but during this
short windows, the CPU0 will not receive interrupts.

The BUG is applicable to only OMAP4460(r2pX) devices.
OMAP4470 (also r2pX) is not affected by this bug because
ROM code has been fixed.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NTero Kristo <t-kristo@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

We want to remove plat/cpu.h. To do this, let's first split
it to private soc.h to mach-omap1 and mach-omap2. We have to
keep plat/cpu.h around until the remaining drivers are fixed,
so let's include the local soc.h in plat/cpu.h and for drivers
still including plat/cpu.h.

Once the drivers are fixed not to include plat/cpu.h, we
can remove the file.

This is needed for the ARM common zImage support.

[tony@atomide.com: updated to not print a warning]
Signed-off-by: NTony Lindgren <tony@atomide.com>

These can now be moved to be local headers in mach-omap2.

Note that this patch removes arch/arm/plat-omap/devices.c as it
will get removed anyways with Paul Walmsley's patch
"ARM: OMAP: split OMAP1, OMAP2+ RNG device registration".
Signed-off-by: NTony Lindgren <tony@atomide.com>

Correcting spelling typo in mach-omap2
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Iteration over all power domains in the idle path is unnecessary since
only power domains that are transitioning need to be accounted for.
Also PRCM register accesses are known to be expensive, so the
additional latency added to the idle path is signficiant.

In order allow the pre/post transitions to be isolated and called
per-pwrdm, change the API so passing in a specific power domain will
trigger the pre/post transtion accounting for only that specific power
domain.  Passing NULL means iterating over all power domains as is
current behavior.
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NGrazvydas Ignotas <notasas@gmail.com>
Acked-by: NPaul Walmsley <paul@pwsan.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Disintegrate asm/system.h for ARM.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: Russell King <linux@arm.linux.org.uk>
cc: linux-arm-kernel@lists.infradead.org

Remove some superfluous calls to pwrdm_clear_all_prev_pwrst().
pwrdm_pre_transition(), which appears a few lines after these calls,
invokes pwrdm_clear_all_prev_pwrst() on each powerdomain -- there's no
need to do it twice.

N.B.: some of us have observed that accesses to the previous
powerstate registers seem to be quite slow.  Although the writes
removed by this patch should be buffered by the write buffer, there is
a read to a PRM register immediately afterwards.  That will block the
OMAP3 MPU until all of those writes complete.  So this patch should
result in a minor performance improvement during idle entry.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NTero Kristo <t-kristo@ti.com>
[khilman@ti.com: removed a couple more for OMAP4]
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

WARNING: arch/arm/mach-omap2/built-in.o(.text+0x8b80):
Section mismatch in reference from the function omap4_hotplug_cpu() to
the function .cpuinit.text:omap_secondary_startup()
The function omap4_hotplug_cpu() references
the function __cpuinit omap_secondary_startup().
This is often because omap4_hotplug_cpu lacks a __cpuinit
annotation or the annotation of omap_secondary_startup is wrong.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

This patch adds the MPUSS OSWR (Open Switch Retention) support. The MPUSS
OSWR configuration is as below.
	- CPUx L1 and logic lost, MPUSS logic lost, L2 memory is retained

OMAP4460 onwards, MPUSS power domain doesn't support OFF state any more
anymore just like CORE power domain. The deepest state supported is OSWR.
On OMAP4430 secure devices too, MPUSS off mode can't be used because of
a bug which alters Ducati and Tesla states. Hence MPUSS off mode as an
independent state isn't supported on OMAP44XX devices.

Ofcourse when MPUSS power domain transitions to OSWR along
with device off mode, it eventually hits off state since memory
contents are lost.

Hence the MPUSS off mode independent state is not attempted without
device off mode. All the necessary infrastructure code for MPUSS
off mode is in place as part of this series.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

When MPUSS hits off-mode, L2 cache is lost. This patch adds L2X0
necessary maintenance operations and context restoration in the
low power code.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

This patch adds MPUSS(MPU Sub System) power domain
CSWR(Close Switch Retention) support to system wide suspend.
For MPUSS power domain to hit retention(CSWR or OSWR), both
CPU0 and CPU1 power domains need to be in OFF or DORMANT state,
since CPU power domain CSWR is not supported by hardware
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Program non-boot CPUs to hit lowest supported power state
when it is off-lined using cpu hotplug framework.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

This patch adds the CPU0 and CPU1 off mode support. CPUX close switch
retention (CSWR) is not supported by hardware design.

The CPUx OFF mode isn't supported on OMAP4430 ES1.0

CPUx sleep code is common for hotplug, suspend and CPUilde.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>