blackbird-op-linux/drivers/clocksource/dw_apb_timer_of.c, branch v4.5

clocksource/drivers/dw_apb_timer_of: Implement ARM delay timer

2015-12-15T08:42:00+00:00

Implement an ARM delay timer to be used for udelay(). This allows us to skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD platforms. And after this patch, udelay() will be unaffected by CPU frequency changes. Note: Although in case there are several possible delay timers, we may not select the "best" delay timer. Take one Marvell Berlin platform for example: we have arch timer and dw-apb timer. The arch timer freq is 25MHZ while the dw-apb timer freq is 100MHZ, current selection would choose the dw-apb timer. But the dw apb timer is on the APB bus while arch timer sits in CPU, the cost of accessing the apb timer is higher than the arch timer. We could introduce "rating" concept to delay timer, but this approach "brings a lot of complexity and workarounds in the code for a small benefit" as pointed out by Daniel. Later, Arnd pointed out "However, we could argue that this actually doesn't matter at all, because the entire point of the ndelay()/ udelay()/mdelay() functions is to waste CPU cycles doing not much at all, so we can just as well waste them reading the timer register than spinning on the CPU reading the arch timer more often.", so we just simply register the dw apb base delay timer. Signed-off-by: Jisheng Zhang Signed-off-by: Daniel Lezcano

clocksource/drivers/dw_apb_timers_of: Fix IO endianness causing time jumps

2015-03-31T07:15:57+00:00

The dw_apb_timer_of timer is using __raw_readl() to access the timer register, which is causing issues when the system is running in big endian mode. Fix this by using readl_relaxed() which should account for the endian settings. This fixes issues where the time jumps around in the dmesg output due to returnling __le32 values. For an example, these two console lines show time running backwards: [ 49.882572] CPU1: failed to come online [ 43.282457] Brought up 1 CPUs Signed-off-by: Ben Dooks Signed-off-by: Daniel Lezcano Acked-by: Nicolas Ferre Cc: Dinh Nguyen Cc: Linux ARM Kernel Cc: Thomas Gleixner Cc: digetx@gmail.com Cc: hdegoede@redhat.com Cc: laurent.pinchart+renesas@ideasonboard.com Cc: maxime.ripard@free-electrons.com Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/1427746633-9137-10-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar

clocksource: dw_apb_timer_of: Do not trace read_sched_clock

2014-05-23T07:23:09+00:00

We do not need to trace read_sched_clock function, so add notrace attribute for this function. Signed-off-by: Yang Wei Signed-off-by: Daniel Lezcano

clocksource: dw_apb_timer_of: Fix support for dts binding "snps,dw-apb-timer"

2013-12-10T18:49:18+00:00

In commit 620f5e1cbf (dts: Rename DW APB timer compatible strings), both "snps,dw-apb-timer-sp" and "snps,dw-apb-timer-osc" were deprecated in place of "snps,dw-apb-timer". But the driver also needs to be udpated in order to support this new binding "snps,dw-apb-timer". Signed-off-by: Dinh Nguyen Signed-off-by: Daniel Lezcano

clocksource: dw_apb_timer_of: Fix read_sched_clock

2013-12-10T18:49:18+00:00

The read_sched_clock should return the ~value because the clock is a countdown implementation. read_sched_clock() should be the same as __apbt_read_clocksource(). Signed-off-by: Dinh Nguyen Signed-off-by: Daniel Lezcano

clocksource: dw_apb_timer_of: Mark a few more functions as __init

2013-10-02T09:43:15+00:00

These are all only called by dw_apb_timer_init which is an __init function, too Signed-off-by: Uwe Kleine-König Signed-off-by: Daniel Lezcano

clocksource: Put nodes passed to CLOCKSOURCE_OF_DECLARE callbacks centrally

2013-10-02T09:42:48+00:00

Instead of letting each driver call of_node_put do it centrally in the loop that also calls the CLOCKSOURCE_OF_DECLARE callbacks. This is less prone to error and also moves getting and putting the references into the same function. Consequently all respective of_node_put calls in drivers are removed. Signed-off-by: Uwe Kleine-König Signed-off-by: Daniel Lezcano Acked-by: David Brown

clocksource: dw_apb_timer_of: Switch to sched_clock_register()

2013-07-30T18:24:52+00:00

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. Signed-off-by: Stephen Boyd Signed-off-by: John Stultz

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-07-06T21:09:38+00:00

Pull timer core updates from Thomas Gleixner: "The timer changes contain: - posix timer code consolidation and fixes for odd corner cases - sched_clock implementation moved from ARM to core code to avoid duplication by other architectures - alarm timer updates - clocksource and clockevents unregistration facilities - clocksource/events support for new hardware - precise nanoseconds RTC readout (Xen feature) - generic support for Xen suspend/resume oddities - the usual lot of fixes and cleanups all over the place The parts which touch other areas (ARM/XEN) have been coordinated with the relevant maintainers. Though this results in an handful of trivial to solve merge conflicts, which we preferred over nasty cross tree merge dependencies. The patches which have been committed in the last few days are bug fixes plus the posix timer lot. The latter was in akpms queue and next for quite some time; they just got forgotten and Frederic collected them last minute." * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits) hrtimer: Remove unused variable hrtimers: Move SMP function call to thread context clocksource: Reselect clocksource when watchdog validated high-res capability posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting posix_timers: fix racy timer delta caching on task exit posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule() selftests: add basic posix timers selftests posix_cpu_timers: consolidate expired timers check posix_cpu_timers: consolidate timer list cleanups posix_cpu_timer: consolidate expiry time type tick: Sanitize broadcast control logic tick: Prevent uncontrolled switch to oneshot mode tick: Make oneshot broadcast robust vs. CPU offlining x86: xen: Sync the CMOS RTC as well as the Xen wallclock x86: xen: Sync the wallclock when the system time is set timekeeping: Indicate that clock was set in the pvclock gtod notifier timekeeping: Pass flags instead of multiple bools to timekeeping_update() xen: Remove clock_was_set() call in the resume path hrtimers: Support resuming with two or more CPUs online (but stopped) timer: Fix jiffies wrap behavior of round_jiffies_common() ...

Revert "dw_apb_timer_of.c: Remove parts that were picoxcell-specific"

2013-06-18T23:02:04+00:00

This reverts commit 55a68c23e0a675b2b8ac2656fd6edbf98b78e4c6. In order to avoid a collision with dw_apb_timer changes in the arm-soc tree, revert this change. I'm leaving it to the arm-soc folks to sort out if they want to keep the other side of the collision or if they're just going to back it all out and try again during the next release cycle. Reported-by: Dinh Nguyen Signed-off-by: John Stultz