omap_sr_disable_reset_volt is called with irqs off in omapx_enter_sleep,
as part of idle sequence, this eventually calls sr_disable and
pm_runtime_put_sync. pm_runtime_put_sync calls rpm_idle, which will
enable interrupts in order to call the callback. In this short interval
when interrupts are enabled, scenarios such as the following can occur:
while interrupts are enabled, the timer interrupt that is supposed to
wake the device out of idle occurs and is acked, so when the CPU finally
goes to off, the timer is already gone, missing a wakeup event.

Further, as the documentation for runtime states:"
 However, subsystems can use the pm_runtime_irq_safe() helper function
 to tell the PM core that a device's ->runtime_suspend() and ->runtime_resume()
 callbacks should be invoked in atomic context with interrupts disabled
 (->runtime_idle() is still invoked the default way)."

Hence, replace pm_runtime_put_sync with pm_runtime_put_sync_suspend
to invoke the suspend handler and shut off the fclk for SmartReflex
module instead of using the idle handler in interrupt disabled context.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NColin Cross <ccross@google.com>
[khilman@ti.com: minor Subject edits]
Signed-off-by: NKevin Hilman <khilman@ti.com>

SmartReflex should be disabled while entering low power mode due to
a) SmartReflex values are not defined for retention voltage, further
b) with SmartReflex enabled, if CPU enters lower c-states, FSM will try
to bump the voltage to current OPP's voltage for which it has entered c-state;
hence SmartReflex needs to be disabled for MPU, CORE and IVA voltage
domains in idle path before enabling auto retention voltage achievement
on the device.

However, since the current pm_runtime setup for SmartReflex devices are
setup to allow callbacks to be invoked with interrupts enabled, calling
SmartReflex enable/disable from other contexts such as idle paths
where preemption is disabled causes warnings such as the following
indicating of a potential race.
[   82.023895] [<c04d079c>] (__irq_svc+0x3c/0x120) from [<c04d0484>] (_raw_spin_unlock_irq+0x28/0x2c)
[   82.023895] [<c04d0484>] (_raw_spin_unlock_irq+0x28/0x2c) from [<c0323234>] (rpm_callback+0x4c/0x68)
[   82.023956] [<c0323234>] (rpm_callback+0x4c/0x68) from [<c0323f7c>] (rpm_resume+0x338/0x53c)
[   82.023956] [<c0323f7c>] (rpm_resume+0x338/0x53c) from [<c03243f4>] (__pm_runtime_resume+0x48/0x60)
[   82.023986] [<c03243f4>] (__pm_runtime_resume+0x48/0x60) from [<c008aee0>] (sr_enable+0xa8/0x19c)
[   82.023986] [<c008aee0>] (sr_enable+0xa8/0x19c) from [<c008b2fc>] (omap_sr_enable+0x50/0x90)
[   82.024017] [<c008b2fc>] (omap_sr_enable+0x50/0x90) from [<c00888c0>] (omap4_enter_sleep+0x138/0x168)

Instead, we use pm_runtime_irq_safe to tell the PM core that callbacks can be
invoked in interrupt disabled contexts.
Acked-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NNishanth Menon <nm@ti.com>
[khilman@ti.com: minor changelog edits]
Signed-off-by: NKevin Hilman <khilman@ti.com>

Error label case seems to have a 2 tab indentation when just 1 is
necessary.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Since we already know the state of the autocomp enablement, we can
see if the requested state is different from the current state and
enable/disable SR only on the need basis.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

We will enable and disable interrupt on a need basis in the class
driver. We need to keep the IRQ disabled by default else the
forceupdate or vcbypass events could trigger events that we don't
need/expect to handle.

This is a preparation for SmartReflex AVS class drivers such as
class 2 and class 1.5 which would need to use interrupts. Existing
SmartReflex AVS class 3 driver does not require to use interrupts
and is not impacted by this change.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Interrupt notification mechanism of SmartReflex can be used by the
choice of implementation of the class driver. For example, Class 2 and
Class 1.5 of SmartReflex can both use the interrupt notification to
identify the transition of voltage or other events.

Hence, the actual class does not matter for notifier. Let the class
driver's handling decide how it should be used. SmartReflex driver
should provide just the primitives.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Delete created debugfs entries if probe fails.
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

If the probe fails, the node should be deleted from sr_list.
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Add missing iounmap() to error paths.
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

We are releasing the memory region, but never actually request it.
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

sr_late_init() will take care of freeing the resources.
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

omap_sr_probe() creates the smartreflex debug directory and its
underlying nvalue debug directory. These directories are removed in
omap_sr_remove().

Basic smartreflex functionality tested on OMAP3630 Zoom3 & OMAP4430 SDP
Signed-off-by: NAnand S Sawant <sawant@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

kzalloc() may fail, if so return -ENOMEM.  Also Walter Harms suggested
to use kasprintf() instead of kzalloc+strcpy+strcat.
Signed-off-by: NVasiliy Kulikov <segoon@openwall.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

There's no reason for this header file to be in
plat-omap/include/plat/smartreflex.h.  The hardware devices are in
OMAP2+ SoCs only.  Leaving this header file in plat-omap causes
problems due to cross-dependencies with other header files that should
live in mach-omap2/.

Thanks to Benoît Cousson <b-cousson@ti.com> for suggesting the removal
of the smartreflex.h include from the OMAP3xxx hwmod data.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Cc: Benoît Cousson <b-cousson@ti.com>

This Patch frees all the dynamically allocated memory
which couldn't have been released in some error hitting cases.
Signed-off-by: NShweta Gulati <shweta.gulati@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Temporary strings with volt_* file names should be released after the
debugfs entries are created. While at it, also simplify the string
allocation, and use just snprintf() to create the name.

The patch eliminates kmemleak reports with the following stack trace
(multiple objects depending on HW):

unreferenced object 0xcedbc5a0 (size 64):
  comm "swapper", pid 1, jiffies 4294929375 (age 423.734s)
  hex dump (first 32 bytes):
    76 6f 6c 74 5f 39 37 35 30 30 30 00 00 00 00 00  volt_975000.....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<c012fee0>] create_object+0x104/0x208
    [<c012dbc8>] kmem_cache_alloc_trace+0xf0/0x17c
    [<c0013f64>] omap_sr_probe+0x314/0x420
    [<c02a1724>] platform_drv_probe+0x18/0x1c
    [<c02a088c>] driver_probe_device+0xc8/0x188
    [<c02a09b4>] __driver_attach+0x68/0x8c
    [<c02a00ac>] bus_for_each_dev+0x44/0x74
    [<c029f9e0>] bus_add_driver+0xa0/0x228
    [<c02a0cac>] driver_register+0xa8/0x130
    [<c02a1b2c>] platform_driver_probe+0x18/0x8c
    [<c0013c1c>] sr_init+0x40/0x74
    [<c005a554>] do_one_initcall+0xc8/0x1a0
    [<c00084f4>] kernel_init+0x150/0x218
    [<c0065d64>] kernel_thread_exit+0x0/0x8
    [<ffffffff>] 0xffffffff
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Don't allow everybody to change voltage settings.
Signed-off-by: NVasiliy Kulikov <segoon@openwall.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Acked-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

These errors were found by cppcheck:
arch/arm/mach-omap2/smartreflex.c:784: error: Possible null pointer dereference: sr_info
arch/arm/mach-omap2/smartreflex.c:799: error: Possible null pointer dereference: sr_info

Both conditional statements are executed when sr_info == NULL,
so accessing sr_info->voltdm would fail.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Signed-off-by: NKevin Hilman <khilman@ti.com>

sr_info was allocated and needs a kfree before returning.

This error was reported by cppcheck:
arch/arm/mach-omap2/smartreflex.c:837: error: Memory leak: sr_info

To: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Acked-by: NShweta Gulati <shweta.gulati@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>

Function _sr_lookup, defined in the same file, returns ERR_PTR not NULL in
an error case.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
identifier f;
@@
f(...) { ... return ERR_PTR(...); }

@@
identifier r.f, fld;
expression x;
statement S1,S2;
@@
 x = f(...)
 ... when != IS_ERR(x)
(
 if (IS_ERR(x) ||...) S1 else S2
|
*x->fld
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NKevin Hilman <khilman@ti.com>

This patch extends the smartreflex framework to support
OMAP4. The changes are minor like compiling smartreflex Kconfig
option for OMAP4 also, and a couple of OMAP4 checks in
the smartreflex framework.

The change in sr_device.c where new logic has to be introduced
for reading the efuse registers is due to the fact that in OMAP4
the efuse registers are 24 bit aligned. A __raw_readl will
fail for non-32 bit aligned address and hence the 8-bit read
and shift.
Signed-off-by: NThara Gopinath <thara@ti.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>

This patch adds debug support to the voltage and smartreflex drivers.
This means a whole bunch of voltage processor and smartreflex
parameters are now visible through the pm debugfs.
The voltage parameters can be viewed at
        /debug/voltage/vdd_<x>/<parameter>
and the smartreflex parameters can be viewed at
        /debug/voltage/vdd_<x>/smartreflex/<parameter>

Also smartreflex n-target values are now exposed out at
	/debug/voltage/vdd_<x>/smartreflex/nvalue/<voltage>

This is a read-write interface which means user has the
flexibility to change the n-target values for any opp.
Signed-off-by: NThara Gopinath <thara@ti.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>

SmartReflex modules do adaptive voltage control for real-time
voltage adjustments. With Smartreflex the power supply voltage
can be adapted to the silicon performance(manufacturing process,
temperature induced performance, age induced performance etc).

There are differnet classes of smartreflex implementation.
	Class-0: Manufacturing Test Calibration
	Class-1: Boot-Time Software Calibration
	Class-2: Continuous Software Calibration
	Class-3: Continuous Hardware Calibration
	Class-4: Fully Integrated Power Management

OMAP3 has two smartreflex modules one associated with VDD MPU and the
other associated with VDD CORE.
This patch adds support for  smartreflex driver. The driver is designed
for Class-1 , Class-2 and Class-3 support and is  a platform driver.
Smartreflex driver can be enabled through a Kconfig option
"SmartReflex support" under "System type"->"TI OMAP implementations" menu.

Smartreflex autocompensation feature can be enabled runtime through
a debug fs option.
To enable smartreflex autocompensation feature
	echo 1 > /debug/voltage/vdd_<X>/smartreflex/autocomp
To disable smartreflex autocompensation feature
	echo 0 > /debug/voltage/vdd_<X>/smartreflex/autocomp

where X can be mpu, core , iva etc.

This patch contains code originally in linux omap pm branch.
Major contributors to this driver are
Lesly A M, Rajendra Nayak, Kalle Jokiniemi, Paul Walmsley,
Nishant Menon, Kevin Hilman.
Signed-off-by: NThara Gopinath <thara@ti.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>