Currently, arch-mmp/time.c uses timer 0 both as a clocksource timer
and as a clockevent timer, the latter by setting up a comparator
interrupt to match on 'current_time + delta'.  This is problematic
if delta is small enough, as that can lead to 'current_time + delta'
already being in the past when comparator setup has finished, leading
to the requested event not triggering.

As there is also a silicon issue that requires stopping a timer's
counter while writing to one of its match registers, we'll switch to
using two separate timers -- timer 0 as clockevent timer, which we'll
start and stop on every invocation of ->set_next_event(), and timer 1
as clocksource timer, which will be free-running.

This first patch enables timer 1 on boot, so that we can use it as
clocksource timer.
Signed-off-by: NLennert Buytenhek <buytenh@laptop.org>
Acked-by: NHaojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: NEric Miao <eric.y.miao@gmail.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Convert mmp to use the new sched_clock() infrastructure for extending
32bit counters to full 64-bit nanoseconds.
Signed-off-by: NRussell 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: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NMikael Pettersson <mikpe@it.uu.se>
Tested-by: NEric Miao <eric.y.miao@gmail.com>
Tested-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

In d7e81c26 (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.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NEric Miao <eric.y.miao@gmail.com>

Marvell MMP2 (aka ARMADA610) is a SoC based on PJ4 core. It's
ARMv6 compatible.  Support basic interrupt handler and timer,
and basic support for MMP2 based FLINT platform.
Signed-off-by: NHaojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: NEric Miao <eric.y.miao@gmail.com>

This patch modifies parameter of clksrc_read() from 'void' to
'struct clocksource *cs', which fixes compile warning for
incompatible parameter type.
Signed-off-by: NColy Li <coly.li@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NEric Miao <eric.miao@marvell.com>

"""The Marvell® PXA168 processor is the first in a family of application
processors targeted at mass market opportunities in computing and consumer
devices. It balances high computing and multimedia performance with low
power consumption to support extended battery life, and includes a wealth
of integrated peripherals to reduce overall BOM cost .... """

See http://www.marvell.com/featured/pxa168.jsp for more information.

  1. Marvell Mohawk core is a hybrid of xscale3 and its own ARM core,
     there are many enhancements like instructions for flushing the
     whole D-cache, and so on

  2. Clock reuses Russell's common clkdev, and added the basic support
     for UART1/2.

  3. Devices are a bit different from the 'mach-pxa' way, the platform
     devices are now dynamically allocated only when necessary (i.e.
     when pxa_register_device() is called). Description for each device
     are stored in an array of 'struct pxa_device_desc'. Now that:

     a. this array of device description is marked with __initdata and
        can be freed up system is fully up

     b. which means board code has to add all needed devices early in
        his initializing function

     c. platform specific data can now be marked as __initdata since
        they are allocated and copied by platform_device_add_data()

  4. only the basic UART1/2/3 are added, more devices will come later.
Signed-off-by: NJason Chagas <chagas@marvell.com>
Signed-off-by: NEric Miao <eric.miao@marvell.com>