sched_clock() is yet another blocker on the road to the single
image. This patch implements an idea by Russell King:
http://www.spinics.net/lists/linux-omap/msg49561.html
Instead of asking the platform to implement both sched_clock()
itself and the rollover callback, simply register a read()
function, and let the ARM code care about sched_clock() itself,
the conversion to ns and the rollover. sched_clock() uses
this read() function as an indirection to the platform code.
If the platform doesn't provide a read(), the code falls back
to the jiffy counter (just like the default sched_clock).
This allow some simplifications and possibly some footprint gain
when multiple platforms are compiled in. Among the drawbacks,
the removal of the *_fixed_sched_clock optimization which could
negatively impact some platforms (sa1100, tegra, versatile
and omap).
Tested on 11MPCore, OMAP4 and Tegra.
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Colin Cross <ccross@android.com>
Cc: Erik Gilling <konkers@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Alessandro Rubini <rubini@unipv.it>
Cc: STEricsson <STEricsson_nomadik_linux@list.st.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Krzysztof Halasa <khc@pm.waw.pl>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We make the reset function from the driver public, then
we also move of all register defines from the public header
file into driver, where they belong.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This adds support for a periodic mode in the MTU (Nomadik)
timer clockevent driver. It also include changes needed for
deeper powerstates where MTU block gets powered off.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This patch makes it possible to configure away the sched_clock
part of the MTU timer.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Mattias Wallin <mattias.wallin@stericsson.com>
Signed-off-by: Jonas Aberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Convert nomadik platforms to use the new sched_clock() infrastructure
for extending 32bit counters to full 64-bit nanoseconds.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ftrace requires sched_clock() to be notrace. Ensure that all
implementations are so marked. Also make sure that they include
linux/sched.h
Also ensure OMAP clocksource read functions are marked notrace as
they're used for sched_clock() too.
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Eric Miao <eric.y.miao@gmail.com>
Tested-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In d7e81c2 (clocksource: Add clocksource_register_hz/khz interface) new
interfaces were added which simplify (and optimize) the selection of the
divisor shift/mult constants. Switch over to using this new interface.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The current implementation of sched_clock() for the Nomadik
family is based on the clock source that will wrap around without
any compensation. Currently on the Ux500 after 1030 seconds.
Utilize cnt32_to_63 to expand the sched_clock() counter to 63
bits and introduce a keepwarm() timer to assure that sched clock
and this cnt32_to_63 is called atleast once every half period.
When I print out the actual wrap-around time, and using
a year (3600*24*365 seconds) as minumum wrap limit I get an
actual wrap-around of:
sched_clock: using 55 bits @ 8333125 Hz wrap in 416 days
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The prescaler 16 is now used only when the timer runs at 32 MHz
or more. Some comment updates as well.
Acked-by: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
timer0 to 3 are all on mtu block 0, so don't calculate the clock event
rate based upon mtu block 1's clock speed.
Acked-by: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This removes the hard-coded shift values for the MTU timer, since
the different platforms using this has very different running
frequencies doing this dynamically is a better idea. Also take
this opportunity to make a more through shutdown of the MTU
clockevent when requested.
Acked-by: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This adjusts the clockrate for the MTU timer. On the different
UX500 variants this rate is different. The platform can also have
been set up at hardware initialization, bootloader or early init
for different clock speeds. To have the clock framework available
early so the timers can use them, the clock initialization for
Nomadik and ux500 is moved to IRQ init time. A custom per-clock
callback is added to handle special cases like this.
This solves a user-visible bug: without this patch the current
UX500 platforms will not be synchronized to wall-clock time and
the platform will drift in time.
Acked-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This provides some serious scheduling for the Nomadik family by
introducing a sched_clock() using the MTU clock source in the
same manner as e.g. OMAP or U300. This type of solutions has been
discussed at no end in the past, however we need this resolution
for making measurements and using HRTimers.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is a complete rewrite of the MTU driver, using one-shot
for events and a free-running timer for stamping. It allows
CONFIG_NO_HZ and CONFIG_HIGH_RES_TIMERS to work on Nomadik and Ux500.
Signed-off-by: Alessandro Rubini <rubini@unipv.it>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Andrea Gallo <andrea.gallo@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
These functions are called with irqs already off. This commit removes
the calls to raw_local_irq_save and raw_local_irq_restore on platforms
that don't have to use a shared interrupt for their timekeeping.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Introduce the plat-nomadik folder for ST-Ericsson
machines including the existing nomadik 8815 architecture.
This also moves the existing MTU (MultiTimerUnit)
of nomadik 8815 to the proposed plat-nomadik and adds
HAS_MTU. The patch has been re-based to 2.6.32-rc6
Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Marc Zyngier