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path: root/drivers/clocksource/arm_global_timer.c
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2016-02-25clockevents/drivers/arm_global_timer: Implement ->set_state_oneshot_stopped()Viresh Kumar
set_state_oneshot_stopped() is called by the clkevt core, when the next event is required at an expiry time of 'KTIME_MAX'. This normally happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes. This patch makes the clockevent device to stop on such an event, to avoid spurious interrupts, as explained by: commit 8fff52fd5093 ("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state"). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2016-02-25clocksource/drivers/arm_global_timer: Register delay timerRabin Vincent
Provide a delay timer using the lower 32-bits of the global timer so that we can use that instead of having to calibrating delays. Signed-off-by: Rabin Vincent <rabin.vincent@axis.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-12-16clocksource/drivers/arm_global_timer: Fix suspend resumeGrygorii Strashko
Now the System stall is observed on TI AM437x based board (am437x-gp-evm) during resuming from System suspend when ARM Global timer is selected as clocksource device (CPUIdle not enabled) - SysRq are working, but nothing else. The reason of stall is that ARM Global timer loses its contexts during System suspend: GT_CONTROL.TIMER_ENABLE = 0 (unbanked) GT_COUNTERx = 0 Hence, update ARM Global timer driver to reflect above behaviour - re-enable ARM Global timer on resume (GT_CONTROL.TIMER_ENABLE = 1) if not enabled. CC: Arnd Bergmann <arnd@arndb.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Felipe Balbi <balbi@ti.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Santosh Shilimkar <ssantosh@kernel.org> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-12-16clockevents/drivers/arm_global_timer: Use writel_relaxed in gt_compare_setJisheng Zhang
Use the relaxed version to improve performance. we measured time of 4096 rounds of gt_compare_set() spent on Marvell BG2Q: before the patch: 3690648ns on average after the patch: 1083023ns on average improved by 70%! Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-10-27clocksource/drivers/arm_global_timer: Prevent ftrace recursionJisheng Zhang
Currently arm_global_timer can be used as a scheduler clock. We properly marked gt_sched_clock_read() as notrace but we then call another function gt_counter_read() that _wasn't_ notrace. Having a traceable function in the sched_clock() path leads to a recursion within ftrace and a kernel crash. Fix this by adding an extra notrace function to keep other users of gt_counter_read() traceable. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-06clockevents/drivers/arm_global_timer: Migrate to new 'set-state' interfaceViresh Kumar
Migrate arm_global_timer driver to the new 'set-state' interface provided by the clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Maxime Coquelin <maxime.coquelin@st.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com> Cc: Maxime Coquelin <maxime.coquelin@st.com> Cc: Patrice Chotard <patrice.chotard@st.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2014-07-18ARM: make it easier to check the CPU part number correctlyRussell King
Ensure that platform maintainers check the CPU part number in the right manner: the CPU part number is meaningless without also checking the CPU implement(e|o)r (choose your preferred spelling!) Provide an interface which returns both the implementer and part number together, and update the definitions to include the implementer. Mark the old function as being deprecated... indeed, using the old function with the definitions will now always evaluate as false, so people must update their un-merged code to the new function. While this could be avoided by adding new definitions, we'd also have to create new names for them which would be awkward. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-22clocksource: arm_global_timer: Only check for unusable timer on A9Matthew Leach
The check for a usable global timer in the probe code does not enquire which CPU we are currently running on. This can cause the driver to incorrectly assume we have an unusable global timer if we are running on a CPU other than A9. Before checking the CPU revision, ensure we are running on an A9 CPU. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Matthew Leach <matthew.leach@arm.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-12-11clocksource: arm_global_timer: Switch to sched_clock_register()Stephen Boyd
The 32 bit sched_clock interface now supports 64 bits. Upgrade to the 64 bit function to allow us to remove the 32 bit registration interface. While we're here increase the number of bits that sched_clock can handle to 64 to make full use of the counter. Cc: Stuart Menefy <stuart.menefy@st.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@st.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@st.com> Acked-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-10-02clocksource/arm_global_timer: Set FEAT_PERCPU flagSoren Brinkmann
The arm_global_timer is a per cpu device. Set the appropriate flag. 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> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
2013-07-14clocksource+irqchip: delete __cpuinit usage from all related filesPaul Gortmaker
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the drivers/clocksource and drivers/irqchip uses of the __cpuinit macros from all C files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-07-03clocksource: arm_global_timer: Add ARM global timer supportStuart Menefy
This is a simple driver for the global timer module found in the Cortex A9-MP cores from revision r1p0 onwards. This should be able to perform the functions of the system timer and the local timer in an SMP system. The global timer has the following features: The global timer is a 64-bit incrementing counter with an auto-incrementing feature. It continues incrementing after sending interrupts. The global timer is memory mapped in the private memory region. The global timer is accessible to all Cortex-A9 processors in the cluster. Each Cortex-A9 processor has a private 64-bit comparator that is used to assert a private interrupt when the global timer has reached the comparator value. All the Cortex-A9 processors in a design use the banked ID, ID27, for this interrupt. ID27 is sent to the Interrupt Controller as a Private Peripheral Interrupt. The global timer is clocked by PERIPHCLK. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com> CC: Arnd Bergmann <arnd@arndb.de> CC: Rob Herring <robherring2@gmail.com> CC: Linus Walleij <linus.walleij@linaro.org> CC: Will Deacon <will.deacon@arm.com> CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>