This prepares the driver for multi-channel support.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

One kzalloc a day keeps the bugs away.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Use the index as the timer start/stop bit and when printing messages to
identify the channel.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The channel memory base is channel-specific, add it to the channel
structure in preparation for support of multiple channels per device.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The name argument is assigned to const structure fields only, constify
it.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Move the channel setup code from sh_tmu_setup to a new
sh_tmu_setup_channel function and call it from sh_tmu_setup.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Channel data is private as well, rename priv to device to make the
distrinction between the core device and the channels clearer.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Create a new sh_tmu_channel structure to hold the channel-specific
field in preparation for multiple channels per device support.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The driver claims it needs to register an interrupt handler too early
for request_irq(). This might have been true in the past, but the only
meaningful difference between request_irq() and setup_irq() today is an
additional kzalloc() call in request_irq(). As the driver calls
kmalloc() itself we know that the slab allocator is available, we can
thus switch to request_irq().
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Clock sources don't need an IRQ, request the IRQ only for channels used
as clock event devices.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

This helps locating duplicates and inserting new headers.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Do not include the paragraph about writing to the Free Software
Foundation's mailing address from the sample GPL notice. The FSF has
changed addresses in the past, and may do so again. Linux already
includes a copy of the GPL.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The sh_cmt driver gets the CMT functional clock using a connection ID of
"cmt_fck". While all SH SoCs create clock lookup entries with a NULL
device ID and a "cmt_fck" connection ID, the ARM SoCs use the device ID
only with a NULL connection ID. This works on legacy platforms but will
break on ARM with DT boot.

Fix the situation by using a connection ID of "fck" in the non-legacy
platform data case. Clock lookup entries will be renamed to use the
device ID as well as the connection ID as platforms get moved to new
platform data. The legacy code will eventually be dropped, leaving us
with device ID based clock lookup, compatible with DT boot.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

CMT hardware devices can support multiple channels, with global
registers and per-channel registers. The sh_cmt driver currently models
the hardware with one Linux device per channel. This model makes it
difficult to handle global registers in a clean way.

Add support for a new model that uses one Linux device per timer with
multiple channels per device. This requires changes to platform data,
add new channel configuration fields.

Support for the legacy model is kept and will be removed after all
platforms switch to the new model.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

All boards use or should use a clock source rating of 125 for the CMT,
hardcode it in the driver.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

All boards use or should use a clock event rating of 125 for the CMT,
hardcode it in the driver.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The CMT is a global timer not restricted to a single CPU. It has a lower
rating than the TMU or ARM architected timer, but is still useful on
systems where the other timers are stopped during CPU sleep.

When multiple timers are available the timers core selects which timer
to use based on timer ratings.

On SMP systems where timer broadcasting is required, one dummy timer is
instantiated per CPU with a rating of 100. On those systems the CMT
timer has a rating of 80, which makes the dummy timer selected by
default on all CPUs. The CMT is then available, and will be used as a
broadcast timer.

On UP systems no dummy timer is instantiated. The CMT timer has a rating
of 125 on those systems and is used directly as a clock event device for
CPU0 without broadcasting.

The CMT rating shouldn't depend on whether we boot a UP or SMP system.
We can't raise the CMT rating to 125 on SMP systems. This would select
CMT as the clock event device for CPU0 as its rating is higher than the
dummy timer rating, and would leave the system without a broadcast
timer. We could instead lower the rating to 80 on all systems, but that
wouldn't reflect reality as ratings between 1 and 99 are documented as
"unfit for real use".

We should raise the rating above 99 and still have the CMT selected as a
broadcast timer. This can be done by changing the cpumask from
cpumask_of(0) to cpu_possible_mask. In that case the timer selection
logic will prefer the previously probed and already selected dummy timer
for all CPUs based on the fact that already selected per-cpu timers are
preferred over new global timers, regardless of their respective
ratings. This also better reflects reality, as the CMT is not tied to
the boot CPU.

Ideally the timer selection logic should realize that the CMT needs to
be used as a broadcast timer on SMP systems as no other broadcast timer
is available, regardless of the cpumask and rating.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Define symbolic macros for all used registers bits.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Create a new sh_cmt_info structure to hold static information about the
device model and reference that structure from the sh_cmt_device
structure.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

This prepares the driver for multi-channel support.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

One kzalloc a day keeps the bugs away.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Use the index when printing messages to identify the channel.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The channel memory base is channel-specific, add it to the channel
structure in preparation for support of multiple channels per device.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The mapbase variable points to the mapped base address of the channel,
rename it to mapbase_sh. mapbase_str points to the mapped base address
of the CMT device, rename it to mapbase.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The name argument is assigned to const structure fields only, constify
it.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Move the channel setup code from sh_cmt_setup to a new
sh_cmt_setup_channel function and call it from sh_cmt_setup.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Channel data is private as well, rename priv to device to make the
distrinction between the core device and the channels clearer.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Create a new sh_cmt_channel structure to hold the channel-specific
field in preparation for multiple channels per device support.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The driver claims it needs to register an interrupt handler too early
for request_irq(). This might have been true in the past, but the only
meaningful difference between request_irq() and setup_irq() today is an
additional kzalloc() call in request_irq(). As the driver calls
kmalloc() itself we know that the slab allocator is available, we can
thus switch to request_irq().
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

If GENERIC_CLOCKEVENTS=n:

drivers/clocksource/sh_cmt.c:54:28: error: field 'ced' has incomplete type
drivers/clocksource/sh_cmt.c: In function 'sh_cmt_interrupt':
drivers/clocksource/sh_cmt.c:407:23: error: 'CLOCK_EVT_MODE_ONESHOT' undeclared (first use in this function)

drivers/clocksource/sh_mtu2.c:44:28: error: field 'ced' has incomplete type
drivers/clocksource/sh_mtu2.c: In function 'ced_to_sh_mtu2':
drivers/clocksource/sh_mtu2.c:184:70: warning: initialization from incompatible pointer type [enabled by default]
drivers/clocksource/sh_mtu2.c: At top level:
drivers/clocksource/sh_mtu2.c:188:16: warning: 'enum clock_event_mode' declared inside parameter list [enabled by default]

drivers/clocksource/sh_tmu.c:45:28: error: field 'ced' has incomplete type
drivers/clocksource/sh_tmu.c: In function 'sh_tmu_interrupt':
drivers/clocksource/sh_tmu.c:207:21: error: 'CLOCK_EVT_MODE_ONESHOT' undeclared (first use in this function)

drivers/clocksource/em_sti.c:44:28: error: field 'ced' has incomplete type
drivers/clocksource/em_sti.c: In function 'ced_to_em_sti':
drivers/clocksource/em_sti.c:251:69: warning: initialization from incompatible pointer type [enabled by default]
drivers/clocksource/em_sti.c: At top level:
drivers/clocksource/em_sti.c:255:16: warning: 'enum clock_event_mode' declared inside parameter list [enabled by default]
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Cc: Magnus Damm <damm@opensource.se>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1395324352-9146-1-git-send-email-geert@linux-m68k.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the clocksource dummy-timer code by using this latter form of callback
registration.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

My guess is we aren't going to have a 2 digit cpuid here any time soon
but the static checkers don't know that and complain that the snprintf()
could overflow.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

The currently used method adjusting the clocksource to a changing input
frequency does not work on kernels from 3.11 on.
The new approach is to keep the timer frequency as constant as possible.
I.e.
 - due to the TTC's prescaler limitations, allow frequency changes
   only if the frequency scales by a power of 2
 - adjust the counter's divider on the fly when a frequency change
   occurs

This limits cpufreq to scale by certain factors only.
But we may keep the time base somewhat constant, so that sleep() & co
keep working as expected, while supporting cpufreq.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NMichal Simek <michal.simek@xilinx.com>

The timer core takes care of serialization and IRQs. Hence the driver is
no longer required to disable interrupts when calling
clockevents_update_freq().
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NMichal Simek <michal.simek@xilinx.com>

Add Kconfig entries for CMT, MTU2, TMU and STI to
drivers/clocksource/Kconfig. This will allow us to
get rid of duplicated entires in architecture code
such as arch/sh and arch/arm/mach-shmobile.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NWolfram Sang <wsa@sang-engineering.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Replace the driver-specific thread-safe shared register API
by the recently introduced atomic_io_clear_set().
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Replace the driver-specific thread-safe shared register API
by the recently introduced atomic_io_clear_set().

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: NWilly Tarreau <w@1wt.eu>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Commit 438e0bff5257 added the timer-keystone device driver but make use
of an unnecessary variable in the init function. This patch deletes this
variable.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Add broadcast clock-event device for the Keystone arch.

The timer can be configured as a general-purpose 64-bit timer,
dual general-purpose 32-bit timers. When configured as dual 32-bit
timers, each half can operate in conjunction (chain mode) or
independently (unchained mode) of each other.
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NSantosh shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@ti.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

The Allwinner A10 compatibles were following a slightly different compatible
patterns than the rest of the SoCs for historical reasons. Add compatibles
matching the other pattern to the timer driver for consistency, and keep the
older one for backward compatibility.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>