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path: root/drivers/clocksource/cadence_ttc_timer.c
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2014-09-29clocksource: cadence_ttc: Add support for 32bit modeMichal Simek1-5/+10
New TTCs support 32bit mode. Older versions support only 16bit modes. Keep 16bit mode as default and 32bit optional. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2014-05-20clocksource: cadence_ttc: Use readl/writel_relaxed instead of __rawMichal Simek1-27/+27
For supporting ARM big-endian is necessary to use proper IO endianess accessors. Based on Ben Dooks BE guide. Similar conversion is done here: "mv_xor: use {readl, writel}_relaxed instead of __raw_{readl, writel}" (sha1: 5733c38ae3473115ac7df3fe19bd2502149d8c51) Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2014-03-11clocksource/cadence_ttc: Overhaul clocksource frequency adjustmentSoren Brinkmann1-20/+84
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>
2014-03-11clocksource/cadence_ttc: Call clockevents_update_freq() with IRQs enabledSoren Brinkmann1-15/+2
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>
2014-01-20Merge branch 'timers-core-for-linus' of ↵Linus Torvalds1-4/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer changes from Ingo Molnar: - ARM clocksource/clockevent improvements and fixes - generic timekeeping updates: TAI fixes/improvements, cleanups - Posix cpu timer cleanups and improvements - dynticks updates: full dynticks bugfixes, optimizations and cleanups * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) clocksource: Timer-sun5i: Switch to sched_clock_register() timekeeping: Remove comment that's mostly out of date rtc-cmos: Add an alarm disable quirk timekeeper: fix comment typo for tk_setup_internals() timekeeping: Fix missing timekeeping_update in suspend path timekeeping: Fix CLOCK_TAI timer/nanosleep delays tick/timekeeping: Call update_wall_time outside the jiffies lock timekeeping: Avoid possible deadlock from clock_was_set_delayed timekeeping: Fix potential lost pv notification of time change timekeeping: Fix lost updates to tai adjustment clocksource: sh_cmt: Add clk_prepare/unprepare support clocksource: bcm_kona_timer: Remove unused bcm_timer_ids clocksource: vt8500: Remove deprecated IRQF_DISABLED clocksource: tegra: Remove deprecated IRQF_DISABLED clocksource: misc drivers: Remove deprecated IRQF_DISABLED clocksource: sh_mtu2: Remove unnecessary platform_set_drvdata() clocksource: sh_tmu: Remove unnecessary platform_set_drvdata() clocksource: armada-370-xp: Enable timer divider only when needed clocksource: clksrc-of: Warn if no clock sources are found clocksource: orion: Switch to sched_clock_register() ...
2013-12-30clocksource: cadence_ttc: Fix mutex taken inside interrupt contextSoren Brinkmann1-8/+13
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>
2013-12-11clocksource: misc drivers: Remove deprecated IRQF_DISABLEDMichael Opdenacker1-2/+1
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>
2013-12-11clocksource: cadence_ttc_timer: Switch to sched_clock_register()Stephen Boyd1-2/+2
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. Cc: Soren Brinkmann <soren.brinkmann@xilinx.com> Cc: Michal Simek <monstr@monstr.eu> Tested-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-07-18clocksource: cadence_ttc: Reuse clocksource as sched_clockSoren Brinkmann1-0/+12
Reuse the TTC clocksource timer as sched clock provider. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Michal Simek <monstr@monstr.eu>
2013-07-18clocksource: cadence_ttc: Remove unused headerSoren Brinkmann1-1/+0
The clk-provider.h header is not required by this driver. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-05-27arm: zynq: Migrate platform to clock controllerSoren Brinkmann1-5/+18
Migrate the Zynq platform and its drivers to use the new clock controller driver. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Signed-off-by: Michal Simek <michal.simek@xilinx.com> Acked-by: Mike Turquette <mturquette@linaro.org>
2013-04-04arm: zynq: Move timer to generic locationMichal Simek1-0/+436
Move zynq timer out of mach folder to generic location and enable it. Signed-off-by: Michal Simek <michal.simek@xilinx.com>