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: Laurent 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: Laurent 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: Laurent 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: Laurent 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: Laurent 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: Laurent 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: Laurent 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: Laurent 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: Laurent 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: Laurent 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: Laurent 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: Geert 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.org
Signed-off-by: Thomas 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: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael 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: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel 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: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Michal 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: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Michal 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: Magnus Damm <damm@opensource.se>
Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Signed-off-by: Daniel 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: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Daniel 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: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Daniel 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: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Daniel 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: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Santosh shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
Signed-off-by: Daniel 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: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Move the U300 timer driver down to the clocksource driver
subsystem and keep arch/arm clean.
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Set the CLOCK_EVT_FEAT_DYNIRQ flag on the memory mapped
clockevent so that we save power by waking up the CPU with the
next event when this timer is used in broadcast mode.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
There should no longer be any IBM x440 systems or those using the
Summit/EXA chipset out in the wild, so remove support for it.
We've done our due diligence in reaching out to any contact information
listed for this chipset and no indication was given that it should be
kept around.
Signed-off-by: David Rientjes <rientjes@google.com>
The majority of the clocksource code for the Qualcomm platform is shared
between newer (multiplatform) and older platforms. However there is a bit
of code that isn't, so only build it for the appropriate config.
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Kumar Gala <galak@codeaurora.org>
Since there may be other clocksources available, this driver should not
trigger a panic simply because it can not determine the frequency of an
external clock. This change refactors the driver to allow a warning to
be printed in this case instead.
Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Cc: Christian Daudt <bcm@fixthebug.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1391559304-26558-1-git-send-email-tim.kryger@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We intend to share the clocksource code for MSM platforms between legacy
and multiplatform supported qcom SoCs.
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Kumar Gala <galak@codeaurora.org>
When an clock is specified in the device tree, enable it and use it to
determine the external clock frequency.
Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Christian Daudt <bcm@fixthebug.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Christian Daudt <bcm@fixthebug.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
The 32-bit sched_clock() interface supports 64 bits since
3.13-rc1. Upgrade to the 64-bit function to allow us to remove
the 32-bit registration interface.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1389922686-6249-1-git-send-email-sboyd@codeaurora.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When the kernel is compiled with:
CONFIG_HIGH_RES_TIMERS=no
CONFIG_HZ_PERIODIC=yes
CONFIG_DEBUG_ATOMIC_SLEEP=yes
The following WARN appears:
WARNING: CPU: 1 PID: 0 at linux/kernel/mutex.c:856 mutex_trylock+0x70/0x1fc()
DEBUG_LOCKS_WARN_ON(in_interrupt())
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.12.0-xilinx-dirty #93
[<c0014a78>] (unwind_backtrace+0x0/0x11c) from [<c0011b6c>] (show_stack+0x10/0x14)
[<c0011b6c>] (show_stack+0x10/0x14) from [<c039120c>] (dump_stack+0x7c/0xc0)
[<c039120c>] (dump_stack+0x7c/0xc0) from [<c001fda4>] (warn_slowpath_common+0x60/0x84)
[<c001fda4>] (warn_slowpath_common+0x60/0x84) from [<c001fe48>] (warn_slowpath_fmt+0x2c/0x3c)
[<c001fe48>] (warn_slowpath_fmt+0x2c/0x3c) from [<c0392658>] (mutex_trylock+0x70/0x1fc)
[<c0392658>] (mutex_trylock+0x70/0x1fc) from [<c02dfc08>] (clk_prepare_lock+0xc/0xe4)
[<c02dfc08>] (clk_prepare_lock+0xc/0xe4) from [<c02e099c>] (clk_get_rate+0xc/0x44)
[<c02e099c>] (clk_get_rate+0xc/0x44) from [<c02d0394>] (ttc_set_mode+0x34/0x78)
[<c02d0394>] (ttc_set_mode+0x34/0x78) from [<c005f794>] (clockevents_set_mode+0x28/0x5c)
[<c005f794>] (clockevents_set_mode+0x28/0x5c) from [<c00607fc>] (tick_broadcast_on_off+0x190/0x1c0)
[<c00607fc>] (tick_broadcast_on_off+0x190/0x1c0) from [<c005f168>] (clockevents_notify+0x58/0x1ac)
[<c005f168>] (clockevents_notify+0x58/0x1ac) from [<c02b99dc>] (cpuidle_setup_broadcast_timer+0x20/0x24)
[<c02b99dc>] (cpuidle_setup_broadcast_timer+0x20/0x24) from [<c006cd04>] (generic_smp_call_function_single_interrupt+0)
[<c006cd04>] (generic_smp_call_function_single_interrupt+0xe0/0x130) from [<c00138c8>] (handle_IPI+0x88/0x118)
[<c00138c8>] (handle_IPI+0x88/0x118) from [<c0008504>] (gic_handle_irq+0x58/0x60)
[<c0008504>] (gic_handle_irq+0x58/0x60) from [<c0012644>] (__irq_svc+0x44/0x78)
Exception stack(0xef099fa0 to 0xef099fe8)
9fa0: 00000001 ef092100 00000000 ef092100 ef098000 00000015 c0399f2c c0579d74
9fc0: 0000406a 413fc090 00000000 00000000 00000000 ef099fe8 c00666ec c000f46c
9fe0: 20000113 ffffffff
[<c0012644>] (__irq_svc+0x44/0x78) from [<c000f46c>] (arch_cpu_idle+0x34/0x3c)
[<c000f46c>] (arch_cpu_idle+0x34/0x3c) from [<c0053980>] (cpu_startup_entry+0xa8/0x10c)
[<c0053980>] (cpu_startup_entry+0xa8/0x10c) from [<000085a4>] (0x85a4)
We are in an interrupt context (IPI) and we are calling clk_get_rate in the
set_mode function which in turn ends up by getting a mutex... Even if that
does not hang, it is a potential kernel deadlock.
It is not allowed to call clk_get_rate() from interrupt context. To
avoid such calls the timer input frequency is stored in the driver's
data struct which makes it accessible to the driver in any context.
[dlezcano] completed the changelog with the WARN trace and added a more
detailed description. Tested on zync zc702.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Since CSR SiRF was converted to multi platform in cf82e0e (ARM: sirf:
enable multiplatform support) the symbol CLOCK_TICK_RATE isn't the
platform specific definition any more, but a global dummy value. There
was no harm introduced in cf82e0e because the global value happens to
match the old platform specific one, still this dummy value isn't
intended to be used and will hopefully disappear soon, so introduce a
local #define and use that instead.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Prepare the clock at probe time, as there is no other appropriate place
in the driver where we're allowed to sleep.
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Exynos5420 is octa-core SoC from Samsung. Hence extend exynos-mct clocksource
driver to support 8 local interrupts.
Also extend dts entries for 8 interrupts.
Signed-off-by: Chander Kashyap <chander.kashyap@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Currently ARCH_BCM has been used for Broadcom
Mobile V7 based SoCs. In order to allow other Broadcom
SoCs to also use mach-bcm directory and files, this patch
renames the original ARCH_BCM to ARCH_BCM_MOBILE, and
uses ARCH_BCM to define any Broadcom chip residing
in mach-bcm directory.
Signed-off-by: Christian Daudt <bcm@fixthebug.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
bcm_timer_ids is no longer used after converting to CLOCKSOURCE_OF_DECLARE.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This patch removes the use of the IRQF_DISABLED flag.
It's a NOOP since 2.6.35 and it will be removed one day.
[dlezcano] : slightly changed the changelog
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This patch removes the use of the IRQF_DISABLED flag.
It's a NOOP since 2.6.35 and it will be removed one day.
[dlezcano] : slightly changed the changelog
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This patch removes the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
[dlezcano] : slightly changed the changelog
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The current code sets the timer divider bits always. However, when
the 25 MHz timer is enabled, this is not needed and has no effect.
As this causes some confusion, rework the code so the divider is
set only when needed, i.e. when the 25 MHz timer is not in use.
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Many platforms rely on clocksource_of_init() being implicitly
called for registering clock sources and will get zero warnings
if no working clock source is available. Let's print a critical
error message if no clock source is found.
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Laurent Pinchart