With coupled idle states, a failure for any CPU to hit a low power
state must be coordinated such that all CPUs abort.

On OMAP4, when entering a coupled state, CPU0 has to wait for CPU1 to
enter its low power state before it can enter its low power state.

This is implemented by letting CPU0 wait for the CPU1 powerdomain to
hit off.  However, there are conditions where CPU1 might abort/fail
and not hit off while CPU0 is waiting for it.  For example, a CPU1
wakeup or a failed attempt to hit off due to hardware conditions.

To avoid the deadlock where CPU0 would continually wait for CPU1 to
hit off-mode, this patch adds a flag to signal when each CPU has come
out of its low-power state.  CPU0 then checks whether CPU1 has hit off
*or* has already completed its attempt to hit off.  If the latter,
CPU0 must abort its attempt to hit a low-power state so the coupled
state enter method can return.

In addition, cpuidle_coupled_parallel_barrier() is used to ensure the
clearing of the 'done' flag is synchronized on all CPUs.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

OMAP4 CPUDILE driver is converted mainly based on notes from the
coupled cpuidle patch series.

The changes include :
- Register both CPUs and C-states to cpuidle driver.
- Set struct cpuidle_device.coupled_cpus
- Set struct cpuidle_device.safe_state to non coupled state.
- Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each
  state that affects multiple cpus.
- Separate ->enter hooks for coupled & simple idle.
- CPU0 wait loop for CPU1 power transition.
- CPU1 wakeup mechanism for the idle exit.
- Enabling ARCH_NEEDS_CPU_IDLE_COUPLED for OMAP4.

Thanks to Kevin Hilman and Colin Cross on the suggestions/fixes
on the intermediate version of this patch.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

We initialized it at compile time, no need to do that at boot
time.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

We are storing the 'omap4_idle_data' in the private data field
of the cpuidle device. As we are using this variable only in this file,
that does not really make sense. Let's use the global variable directly.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

We initialize the omap4_idle_data variable at compile time allowing us
to remove in the next patch the initialization done at boot time.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Add the static declaration for the omap4_idle_data variable because its scope
is in the file only.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

We do not longer need this table as we defined the values
in the driver states.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

The cpuidle API allows to declare statically the states in the driver
structure. Let's use it.
We do no longer need the fill_cstate function called at runtime and
by the way adding more instructions at boot time.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

The 'valid' field is never used in the code, let's remove it.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Enable core cpuidle timekeeping and irq enabling and remove that
handling from this code.
Signed-off-by: NRobert Lee <rob.lee@linaro.org>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Reviewed-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NJean Pihet <j-pihet@ti.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

OMAP4 cpuidle driver is reporting the state requested by governor
rather than the actually attempted one.

This is obviously misleading sysfs and powertop cpuidle statistics.
Fix it so that stats are reported correctly.
Reported-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
[khilman@ti.com: minor changelog edits]
Signed-off-by: NKevin Hilman <khilman@ti.com>

CPU local timer(TWD) stops when the CPU is transitioning into
deeper C-States. Since these timers are not wakeup capable, we
need the wakeup capable global timer to program the wakeup time
depending on the next timer expiry.

It can be handled by registering a global wakeup capable timer along
with local timers marked with (mis)feature flag CLOCK_EVT_FEAT_C3STOP.
Then notify the clock events layer from idle code using
CLOCK_EVT_NOTIFY_BROADCAST_ENTER/EXIT).

ARM local timers are already marked with C3STOP feature. Add the
notifiers to OMAP4 CPU idle code for the broadcast entry and exit.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Add OMAP4 CPUIDLE support. CPU1 is left with defualt idle and
the low power state for it is managed via cpu-hotplug.

This patch adds MPUSS low power states in cpuidle.

	C1 - CPU0 ON + CPU1 ON + MPU ON
	C2 - CPU0 OFF + CPU1 OFF + MPU CSWR
	C3 - CPU0 OFF + CPU1 OFF + MPU OSWR

OMAP4460 onwards, MPUSS power domain doesn't support OFF state any more
anymore just like CORE power domain. The deepest state supported is OSWr.
Ofcourse when MPUSS and CORE PD transitions to OSWR along with device
off mode, even the memory contemts are lost which is as good as
the PD off state.

On OMAP4 because of hardware constraints, no low power states are
targeted when both CPUs are online and in SMP mode. The low power
states are attempted only when secondary CPU gets offline to OFF
through hotplug infrastructure.

Thanks to Nicole Chalhoub <n-chalhoub@ti.com> for doing exhaustive
C-state latency profiling.
Signed-off-by: NRajendra Nayak <rnayak@ti.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>