Describe minimal DT boot machine details for AM43x based SoC's. AM43x
SoC's are ARM Cortex-A9 based with one core. AM43x is similar to
AM335x w.r.t L4 PER/WKUP memory map. AM43x has a sync timer, here that
is being used as clocksource, while 1ms dmtimer as clockevent.
Signed-off-by: NAnkur Kishore <a-kishore@ti.com>
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

I badly screwed up the merge in commit 6fa52ed3 ("Merge tag
'drivers-for-linus' of git://git.kernel.org/pub/.../arm-soc") by
incorrectly taking the arch/arm/mach-omap2/* data fully from the merge
target because the 'drivers-for-linus' branch seemed to be a proper
superset of the duplicate ARM commits.

That was bogus: commit ff931c82 ("ARM: OMAP: clocks: Delay clk inits
atleast until slab is initialized") only existed in head, and the
changes to arch/arm/mach-omap2/timer.c from that commit got list.

Re-doing the merge more carefully, I do think this part was the only
thing I screwed up.  Knock wood.
Reported-by: NTony Lindgren <tony@atomide.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Looks like the timer.c fixes in commit ff931c82 (ARM: OMAP: clocks:
Delay clk inits atleast until slab is initialized) got lost in a
merge with da4a686a (ARM: smp_twd: convert to use CLKSRC_OF init).

Without the omap_clk_init() calls none of OMAP family of devices
boot.
Signed-off-by: NVaibhav Hiremath <hvaibhav@ti.com>
[tony@atomide.com: updated comments to describe merge error]
Signed-off-by: NTony Lindgren <tony@atomide.com>

Consistently check errors using the usual method used in the kernel
for much of its history.  For instance:

int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
{
	int div;
	div = gpmc_calc_divider(t->sync_clk);
	if (div < 0)
		return div;
static int gpmc_set_async_mode(int cs, struct gpmc_timings *t)
{
...
	return gpmc_cs_set_timings(cs, t);

.....
	ret = gpmc_set_async_mode(gpmc_onenand_data->cs, &t);
	if (IS_ERR_VALUE(ret))
		return ret;

So, gpmc_cs_set_timings() thinks any negative return value is an error,
but where we check that in higher levels, only a limited range are
errors...

There is only _one_ use of IS_ERR_VALUE() in arch/arm which is really
appropriate, and that is in arch/arm/include/asm/syscall.h:

static inline long syscall_get_error(struct task_struct *task,
				     struct pt_regs *regs)
{
	unsigned long error = regs->ARM_r0;
	return IS_ERR_VALUE(error) ? error : 0;
}

because this function really does have to differentiate between error
return values and addresses which look like negative numbers (eg, from
mmap()).

So, here's a patch to remove them from OMAP, except for the above.
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit 0583fe47 "ARM: convert arm/arm64 arch timer to use CLKSRC_OF init"
has left the omap5_realtime_timer_init() function with a stale variable and
broken whitespace. This fixes both.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

This converts arm and arm64 to use CLKSRC_OF DT based initialization for
the arch timer. A new function arch_timer_arch_init is added to allow for
arch specific setup.

This has a side effect of enabling sched_clock on omap5 and exynos5. There
should not be any reason not to use the arch timers for sched_clock.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

Update the DMTIMER compatibility property to reflect the register level
compatibilty between devices and update the various OMAP/AM timer
bindings with the appropriate compatibility string.

By doing this we can add platform specific data applicable to specific
timer versions to the driver. For example, errata flags can be populated
for the timer versions that are impacted.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBenoit Cousson <benoit.cousson@linaro.org>

Commit 6bb27d73 (ARM: delete struct sys_timer) changed the function
created by the macro OMAP_SYS_32K_TIMER_INIT from static void to void.
For OMAP4+ devices this created the following sparse warning ...

arch/arm/mach-omap2/timer.c:585:1: warning: symbol
	'omap4_sync32k_timer_init' was not declared. Should it be static?

The function omap4_sync32k_timer_init() is not referenced outside of the
file timer.c and so make this function static.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

Currently, the timer ID is being passed to the function
omap_dm_timer_init_one(). Instead of passing the ID separately, store it
in the omap_dm_timer structure, that is also passed, and access the ID
from this structure.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

When booting with device-tree for OMAP3 and AM335x devices and a gptimer
is used as the clocksource (which is always the case for AM335x), a
gptimer located in a power domain that is not always-on is selected.
Ideally we should use a gptimer for clocksource that is located in a
power domain that is always on (such as the wake-up domain) so that time
can be maintained during a kernel suspend without keeping on additional
power domains unnecessarily.

In order to fix this so that we can select a gptimer located in a power
domain that is always-on, the following changes were made ...
1. Currently, only when selecting a gptimer to use for a clockevent
   timer, do we pass a timer property that can be used to select a
   specific gptimer. Change this so that we can pass a property when
   selecting a gptimer to use for a clocksource timer too.
2. Currently, when selecting either a gptimer to use for a clockevent
   timer or a clocksource timer and no timer property is passed, then
   the first available timer is selected regardless of the properties
   it has. Change this so that if no properties are passed, then a timer
   that does not have additional features (such as always-on, dsp-irq,
   pwm, and secure) is selected.

For OMAP3 and AM335x devices that use a gptimer for clocksource, change
the selection of the gptimer so that by default the gptimer located in
the always-on power domain is used for clocksource instead of
clockevents.

Please note that using a gptimer for both clocksource and clockevents
can have a system power impact during idle. The reason being is that
OMAP and AMxxx devices typically only have one gptimer in a power domain
that is always-on. Therefore when the kernel is idle both the clocksource
and clockevent timers will be active and this will keep additional power
domains on. During kernel suspend, only the clocksource timer is active
and therefore, it is better to use a gptimer in a power domain that is
always-on for clocksource.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NIgor Grinberg <grinberg@compulab.co.il>

There is a lot of redundancy in the definitions for the various system
timers for OMAP2+ devices. For example, the omap3_am33xx_gptimer_timer_init()
function is the same as the omap3_gp_gptimer_timer_init() function and the
function omap4_sync32k_timer_init() can be re-used for OMAP5 devices.
Therefore, consolidate the definitions to simplify the code.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NIgor Grinberg <grinberg@compulab.co.il>

In commit c59b537d (ARM: OMAP2+: Simplify dmtimer clock aliases), new
clock aliases for dmtimers were added to simplify the code. These clock
aliases can also be used when configuring the system timers and allow us
to remove the current definitions, simplifying the code.

Please note that for OMAP4/5 devices (unlike OMAP2/3 devices), there is
no clock alias for "timer_sys_ck" with NULL as the device name. Therefore
we still need to use the alias "sys_clkin_ck" for these devices.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

Currently, when configuring the clock-events and clock-source timers
for OMAP2+ devices, we check whether the timer ID is 12 before
attempting to set the parent clock for the timer.

This test was added for OMAP3 general purpose devices (no security
features enabled) that a 12th timer available but unlike the other
timers only has a single functional clock source. Calling
clk_set_parent() for this 12th timer would always return an error
because there is only one choice for a parent clock. Therefore,
this hard-coded timer ID test was added.

To avoid this timer ID test, simply check to see if the timer's current
parent clock is the desired parent clock and only call clk_set_parent()
if this is not the case.

Also if clk_get() fails, then use PTR_ERR() to return the error code.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

Currently on boot, when displaying the name of the gptimer used for
clockevents and clocksource timers, the timer ID is shown. However,
when booting with device-tree, the timer ID is not used to select a
gptimer but a timer property. Hence, it is possible that the timer
selected when booting with device-tree does not match the ID shown.
Therefore, instead display the HWMOD name of the gptimer and use
the HWMOD name as the name of clockevent and clocksource timer (if a
gptimer is used).
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

clk inits on OMAP happen quite early, even before slab is available.
The dependency comes from the fact that the timer init code starts to
use clocks and hwmod and we need clocks to be initialized by then.

There are various problems doing clk inits this early, one is,
not being able to do dynamic clk registrations and hence the
dependency on clk-private.h. The other is, inability to debug
early kernel crashes without enabling DEBUG_LL and earlyprintk.

Doing early clk init also exposed another instance of a kernel
panic due to a BUG() when CONFIG_DEBUG_SLAB is enabled.

[    0.000000] Kernel BUG at c01174f8 [verbose debug info unavailable]
[    0.000000] Internal error: Oops - BUG: 0 [#1] SMP ARM
[    0.000000] Modules linked in:
[    0.000000] CPU: 0    Not tainted  (3.9.0-rc1-12179-g72d48f9 #6)
[    0.000000] PC is at __kmalloc+0x1d4/0x248
[    0.000000] LR is at __clk_init+0x2e0/0x364
[    0.000000] pc : [<c01174f8>]    lr : [<c0441f54>]    psr: 600001d3
[    0.000000] sp : c076ff28  ip : c065cefc  fp : c0441f54
[    0.000000] r10: 0000001c  r9 : 000080d0  r8 : c076ffd4
[    0.000000] r7 : c074b578  r6 : c0794d88  r5 : 00000040  r4 : 00000000
[    0.000000] r3 : 00000000  r2 : c07cac70  r1 : 000080d0  r0 : 0000001c
[    0.000000] Flags: nZCv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
[    0.000000] Control: 10c53c7d  Table: 8000404a  DAC: 00000017
[    0.000000] Process swapper (pid: 0, stack limit = 0xc076e240)
[    0.000000] Stack: (0xc076ff28 to 0xc0770000)
[    0.000000] ff20:                   22222222 c0794ec8 c06546e8 00000000 00000040 c0794d88
[    0.000000] ff40: c074b578 c076ffd4 c07951c8 c076e000 00000000 c0441f54 c074b578 c076ffd4
[    0.000000] ff60: c0793828 00000040 c0794d88 c074b578 c076ffd4 c0776900 c076e000 c07272ac
[    0.000000] ff80: 2f800000 c074c968 c07f93d0 c0719780 c076ffa0 c076ff98 00000000 00000000
[    0.000000] ffa0: 00000000 00000000 00000000 00000001 c074cd6c c077b1ec 8000406a c0715724
[    0.000000] ffc0: 00000000 00000000 00000000 00000000 00000000 c074c968 10c53c7d c0776974
[    0.000000] ffe0: c074cd6c c077b1ec 8000406a 411fc092 00000000 80008074 00000000 00000000
[    0.000000] [<c01174f8>] (__kmalloc+0x1d4/0x248) from [<c0441f54>] (__clk_init+0x2e0/0x364)
[    0.000000] [<c0441f54>] (__clk_init+0x2e0/0x364) from [<c07272ac>] (omap4xxx_clk_init+0xbc/0x140)
[    0.000000] [<c07272ac>] (omap4xxx_clk_init+0xbc/0x140) from [<c0719780>] (setup_arch+0x15c/0x284)
[    0.000000] [<c0719780>] (setup_arch+0x15c/0x284) from [<c0715724>] (start_kernel+0x7c/0x334)
[    0.000000] [<c0715724>] (start_kernel+0x7c/0x334) from [<80008074>] (0x80008074)
[    0.000000] Code: e5883004 e1a00006 e28dd00c e8bd8ff0 (e7f001f2)
[    0.000000] ---[ end trace 1b75b31a2719ed1c ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!

It was a know issue, that slab allocations would fail when common
clock core tries to cache parent pointers for mux clocks on OMAP,
and hence a patch 'clk: Allow late cache allocation for clk->parents,
commit 7975059d' was added to work this problem around.
A BUG() within kmalloc() with CONFIG_DEBUG_SLAB enabled was completely
overlooked causing this regression.

More details on the issue reported can be found here,
http://www.mail-archive.com/linux-omap@vger.kernel.org/msg85932.html

With all these issues around clk inits happening way too early, it
makes sense to at least move them to a point where dynamic memory
allocations are possible. So move them to a point just before the
timer code starts using clocks and hwmod.

This should at least pave way for clk inits on OMAP moving to dynamic
clock registrations instead of using the static macros defined in
clk-private.h.

The issue with kernel panic while CONFIG_DEBUG_SLAB is enabled
was reported by Piotr Haber and Tony Lindgren and this patch
fixes the reported issue as well.
Reported-by: NPiotr Haber <phaber@broadcom.com>
Reported-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: NMike Turquette <mturquette@linaro.org>
Acked-by: NPaul Walmsley <paul@pwsan.com>
Cc: stable@vger.kernel.org  # v3.8
Signed-off-by: NTony Lindgren <tony@atomide.com>

OMAP5 clockdata has different sys clock node name. Fix the timer code
to take care of it.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

Consistently check errors using the usual method used in the kernel
for much of its history.  For instance:

int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
{
	int div;
	div = gpmc_calc_divider(t->sync_clk);
	if (div < 0)
		return div;
static int gpmc_set_async_mode(int cs, struct gpmc_timings *t)
{
...
	return gpmc_cs_set_timings(cs, t);

.....
	ret = gpmc_set_async_mode(gpmc_onenand_data->cs, &t);
	if (IS_ERR_VALUE(ret))
		return ret;

So, gpmc_cs_set_timings() thinks any negative return value is an error,
but where we check that in higher levels, only a limited range are
errors...

There is only _one_ use of IS_ERR_VALUE() in arch/arm which is really
appropriate, and that is in arch/arm/include/asm/syscall.h:

static inline long syscall_get_error(struct task_struct *task,
				     struct pt_regs *regs)
{
	unsigned long error = regs->ARM_r0;
	return IS_ERR_VALUE(error) ? error : 0;
}

because this function really does have to differentiate between error
return values and addresses which look like negative numbers (eg, from
mmap()).

So, here's a patch to remove them from OMAP, except for the above.
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Now that we have OF based init with CLKSRC_OF, convert smp_twd init
function to use it and covert all callers of
twd_local_timer_of_register.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-omap@vger.kernel.org
Cc: spear-devel@list.st.com
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

Commit 9725f445 (ARM: OMAP: Add DT support for timer driver) added
device-tree support for selecting a clockevent timer by property.
However, the code is currently ignoring the property passed and
selecting the first available timer found. Hence, for the OMAP3 beagle
board timer-12 is not being selected as expected. Fix this problem
by ensuring the timer property is passed to omap_get_timer_dt().
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NVaibhav Bedia <vaibhav.bedia@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

Remove now-obsolete code from arch/arm/mach-omap2/omap_device.c.  This
mostly consists of removing the first attempt at device PM latency
handling.  This was never really used, has been replaced by the common
dev_pm_qos code, and needs to go away as part of the DT conversion.
Also, the early platform_device creation code has been removed, as it
appears to be unused.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>

The iterator correctly handles of_node_put() calls.
Remove it before continue'ing the loop.
Without this patch you get the following with
CONFIG_OF_DYNAMIC set:

ERROR: Bad of_node_put() on /ocp/timer@44e31000!
[<c001329c>] (unwind_backtrace+0x0/0xe0) from [<c03dd8f0>] (of_node_release+0x2c/0xa0)!
[<c03dd8f0>] (of_node_release+0x2c/0xa0) from [<c03ddea0>] (of_find_matching_node_and_match+0x78/0x90)!
[<c03ddea0>] (of_find_matching_node_and_match+0x78/0x90) from [<c06d349c>] (omap_get_timer_dt+0x78/0x90)!
[<c06d349c>] (omap_get_timer_dt+0x78/0x90) from [<c06d3664>] (omap_dm_timer_init_one.clone.2+0x34/0x2bc)!
[<c06d3664>] (omap_dm_timer_init_one.clone.2+0x34/0x2bc) from [<c06d3a2c>] (omap2_gptimer_clocksource_init.clone.4+0x24/0xa8)!
[<c06d3a2c>] (omap2_gptimer_clocksource_init.clone.4+0x24/0xa8) from [<c06cca58>] (time_init+0x20/0x30)!
[<c06cca58>] (time_init+0x20/0x30) from [<c06c9690>] (start_kernel+0x1a8/0x2fc)!
Signed-off-by: NPantelis Antoniou <panto@antoniou-consulting.com>
Acked-by: NJon Hunter <jon-hunter@ti.com>
[tony@atomide.com: updated description per Jon]
Signed-off-by: NTony Lindgren <tony@atomide.com>

The clockevent core is able to figure out the best mult and shift,
calculate min_delta_ns and max_delta_ns, with the necessary info passed
into clockevents_config_and_register().  Use this combined configure
and register function where possible to make the codes less error prone
and gain some positive diff stat.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Tested-by: NRoland Stigge <stigge@antcom.de>
Acked-by: NEric Miao <eric.y.miao@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: NTony Lindgren <tony@atomide.com>
Acked-by: NBarry Song <baohua.song@csr.com>
Tested-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NTony Prisk <linux@prisktech.co.nz>
Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NOlof Johansson <olof@lixom.net>

This way the initcalls don't run on other SoCs on multiplatform
kernels. Otherwise we'll get something like this when booting
on vexpress:

omap_hwmod: _ensure_mpu_hwmod_is_setup: MPU initiator hwmod mpu not yet registered
...
WARNING: at arch/arm/mach-omap2/pm.c:82 _init_omap_device+0x74/0x94()
_init_omap_device: could not find omap_hwmod for mpu
...
omap-dma-engine omap-dma-engine: OMAP DMA engine driver
...
Tested-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

Now that the only field in struct sys_timer is .init, delete the struct,
and replace the machine descriptor .timer field with the initialization
function itself.

This will enable moving timer drivers into drivers/clocksource without
having to place a public prototype of each struct sys_timer object into
include/linux; the intent is to create a single of_clocksource_init()
function that determines which timer driver to initialize by scanning
the device dtree, much like the proposed irqchip_init() at:
http://www.spinics.net/lists/arm-kernel/msg203686.html

Includes mach-omap2 fixes from Igor Grinberg.
Tested-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NStephen Warren <swarren@nvidia.com>

prom_add_property() has been renamed to of_add_property()
This patch fixes the following comilation error:

arch/arm/mach-omap2/timer.c: In function ‘omap_get_timer_dt’:
arch/arm/mach-omap2/timer.c:178:3: error: implicit declaration of function ‘prom_add_property’ [-Werror=implicit-function-declaration]
cc1: some warnings being treated as errors
make[1]: *** [arch/arm/mach-omap2/timer.o] Error 1
make[1]: *** Waiting for unfinished jobs....
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Sparse generates the following warnings when compiling mach-omap2/timer.c.

  CHECK   arch/arm/mach-omap2/timer.c
  arch/arm/mach-omap2/timer.c:193:13: warning: symbol 'omap_dmtimer_init'
  was not declared. Should it be static?
  arch/arm/mach-omap2/timer.c:213:12: warning: symbol
  'omap_dm_timer_get_errata' was not declared. Should it be static?

Add static to function declaration to fix warnings.
Signed-off-by: NVaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

When compiling the kernel with configuration options ...

 # CONFIG_ARCH_OMAP2 is not set
 # CONFIG_ARCH_OMAP3 is not set
 # CONFIG_ARCH_OMAP4 is not set
 # CONFIG_SOC_OMAP5 is not set
 CONFIG_SOC_AM33XX=y

 ... the following build warning is seen.

  CC      arch/arm/mach-omap2/timer.o
  arch/arm/mach-omap2/timer.c:395:19: warning: ‘omap2_sync32k_clocksource_init’
  	defined but not used [-Wunused-function]

This issue was introduced by commit 6f80b3bb (ARM: OMAP2+: timer: remove
CONFIG_OMAP_32K_TIMER) where the omap2_sync32k_clocksource_init() is no
longer referenced by the timer initialisation function for the AM335x
device as it has no 32k-sync timer.

Fix this by adding the "__maybe_unused" compiler directive to the
omap2_sync32k_clocksource_init() function to indicate that this function
may be used for certain configurations.

Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

Fix 32 vs 32k typo:

arch/arm/mach-omap2/timer.c: In function 'omap4_local_timer_init':
arch/arm/mach-omap2/timer.c:633:2: error: implicit declaration of function 'omap4_sync32_timer_init' [-Werror=implicit-function-declaration]
arch/arm/mach-omap2/timer.c: At top level:
arch/arm/mach-omap2/timer.c:610:2: warning: 'omap4_sync32k_timer_init' defined but not used [-Wunused-function]

Also, mark the omap4_local_timer_init() stub as __init (and take off
the explicit inline and let the compiler do the work instead).
Signed-off-by: NOlof Johansson <olof@lixom.net>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Igor Grinberg <grinberg@compulab.co.il>

cm-t3517 starting from revision 1.2 does not have the 32K oscilator
wired to the AM3517 SoC.
Therefore switch to use the GPTIMER for system clock.
Signed-off-by: NIgor Grinberg <grinberg@compulab.co.il>
Signed-off-by: NTony Lindgren <tony@atomide.com>

CONFIG_OMAP_32K_TIMER is kind of standing on the single zImage way.
Make OMAP2+ timer code independant from the CONFIG_OMAP_32K_TIMER
setting.
To remove the dependancy, several conversions/additions had to be done:
1) Timer initialization functions are named by the platform
   name and the clock source in use.
   This also makes it possible to define and use the GPTIMER as the
   clock source instead of the 32K timer on platforms that do not have
   the 32K timer ip block or the 32K timer is not wired on the board.
   Currently, the the timer is chosen in the machine_desc structure on
   per board basis. Later, DT should be used to choose the timer.
2) Settings under the CONFIG_OMAP_32K_TIMER option are used as defaults
   and those under !CONFIG_OMAP_32K_TIMER are removed.
   This removes the CONFIG_OMAP_32K_TIMER on OMAP2+ timer code.
3) Since we have all the timers defined inside machine_desc structure
   and we no longer need the fallback to gp_timer clock source in case
   32k_timer clock source is unavailable (namely on AM33xx), we no
   longer need the #ifdef around omap2_sync32k_clocksource_init()
   function. Remove the #ifdef CONFIG_OMAP_32K_TIMER around the
   omap2_sync32k_clocksource_init() function.
Signed-off-by: NIgor Grinberg <grinberg@compulab.co.il>
Cc: Jon Hunter <jon-hunter@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Vaibhav Hiremath <hvaibhav@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: NJon Hunter <jon-hunter@ti.com>

Commit "ARM: OMAP2+: Add device-tree support for 32kHz counter"
added structure omap_counter_match to the OMAP2 timer code. When
CONFIG_OMAP_32K_TIMER is not defined this structure generates the
following as it is not used.

  CC      arch/arm/mach-omap2/timer.o
  arch/arm/mach-omap2/timer.c:163:28: warning: 'omap_counter_match'
  defined but not used [-Wunused-variable]

Move the definition of omap_counter_match to avoid this warning when
CONFIG_OMAP_32K_TIMER is not set.

Thanks to Kevin Hilman for tracking down and reporting this problem.
Reported-by: NKevin Hilam <khilman@deeprootsystems.com>
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

Move definition of dmtimer platform data structure in to its own header
under <linux/platform_data>.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

The function omap_dm_timer_init_one() declares two local variables of
type int that are used to store the return value of functions called.
One such local variable is sufficient and so remove one of these local
variables.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

The OMAP2+ system timer code stores the physical address of the timer
but never uses it. Remove this and clean-up the code by removing the
local variable "size" and changing the names of the local variables
mem_rsrc and irq_rsrc to mem and irq, respectively.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

The __omap_dm_timer_set_source() function is only used by the system timer
(clock-events and clock-source) code for OMAP2+ devices. Therefore, we can
remove this code from the dmtimer driver and move it to the system timer
code for OMAP2+ devices.

The current __omap_dm_timer_set_source() function calls clk_disable() before
calling clk_set_parent() and clk_enable() afterwards. We can avoid these calls
to clk_disable/enable by moving the calls to omap_hwmod_setup_one() and
omap_hwmod_enable() to after the call to clk_set_parent() in
omap_dm_timer_init_one().

The function omap_hwmod_setup_one() will enable the timers functional clock
and therefore increment the use-count of the functional clock to 1.
clk_set_parent() will fail if the use-count is not 0 when called. Hence, if
omap_hwmod_setup_one() is called before clk_set_parent(), we will need to call
clk_disable() before calling clk_set_parent() to decrement the use-count.
Hence, avoid these extra calls to disable and enable the functional clock by
moving the calls to omap_hwmod_setup_one() and omap_hwmod_enable() to after
clk_set_parent().

We can also remove the delay from the __omap_dm_timer_set_source() function
because enabling the clock will now be handled via the HWMOD framework by
calling omap_hwmod_setup_one(). Therefore, by moving the calls to
omap_hwmod_setup_one() and omap_hwmod_enable() to after the call to
clk_set_parent(), we can simply replace __omap_dm_timer_set_source() with
clk_set_parent().

It should be safe to move these hwmod calls to later in the
omap_dm_timer_init_one() because other calls to the hwmod layer that occur
before are just requesting resource information.

Testing includes boot testing on OMAP2420 H4, OMAP3430 SDP and OMAP4430 Blaze
with the following configurations:
1. CONFIG_OMAP_32K_TIMER=y
2. CONFIG_OMAP_32K_TIMER=y and boot parameter "clocksource=gp_timer"
3. CONFIG_OMAP_32K_TIMER not set
4. CONFIG_OMAP_32K_TIMER not set and boot parameter "clocksource=gp_timer"
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

Currently OMAP2+ devices are using the function __omap_dm_timer_reset() to
configure the clock-activity, idle, wakeup-enable and auto-idle fields in the
timer OCP_CFG register. The name of the function is mis-leading because this
function does not actually perform a reset of the timer.

For OMAP2+ devices, HWMOD is responsible for reseting and configuring the
timer OCP_CFG register. Therefore, do not use __omap_dm_timer_reset() for
OMAP2+ devices and rely on HWMOD. Furthermore, some timer instances do not
have the fields clock-activity, wakeup-enable and auto-idle and so this
function could configure the OCP_CFG register incorrectly.

Currently HWMOD is not configuring the clock-activity field in the OCP_CFG
register for timers that have this field. Commit 0f0d0807 (ARM: OMAP: DMTimer:
Use posted mode) configures the clock-activity field to keep the f-clk enabled
so that the wake-up capability is enabled. Therefore, add the appropriate flags
to the timer HWMOD structures to configure this field in the same way.

For OMAP2/3 devices all dmtimers have the clock-activity field, where as for
OMAP4 devices, only dmtimer 1, 2 and 10 have the clock-activity field.

Verified on OMAP2420 H4, OMAP3430 Beagle and OMAP4430 Panda that HWMOD is
configuring the dmtimer OCP_CFG register as expected for clock-events timer.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

Errata Titles:
i103: Delay needed to read some GP timer, WD timer and sync timer
      registers after wakeup (OMAP3/4)
i767: Delay needed to read some GP timer registers after wakeup (OMAP5)

Description (i103/i767):
If a General Purpose Timer (GPTimer) is in posted mode
(TSICR [2].POSTED=1), due to internal resynchronizations, values read in
TCRR, TCAR1 and TCAR2 registers right after the timer interface clock
(L4) goes from stopped to active may not return the expected values. The
most common event leading to this situation occurs upon wake up from
idle.

GPTimer non-posted synchronization mode is not impacted by this
limitation.

Workarounds:
1). Disable posted mode
2). Use static dependency between timer clock domain and MPUSS clock
    domain
3). Use no-idle mode when the timer is active

Workarounds #2 and #3 are not pratical from a power standpoint and so
workaround #1 has been implemented. Disabling posted mode adds some CPU
overhead for configuring and reading the timers as the CPU has to wait
for accesses to be re-synchronised within the timer. However, disabling
posted mode guarantees correct operation.

Please note that it is safe to use posted mode for timers if the counter
(TCRR) and capture (TCARx) registers will never be read. An example of
this is the clock-event system timer. This is used by the kernel to
schedule events however, the timers counter is never read and capture
registers are not used. Given that the kernel configures this timer
often yet never reads the counter register it is safe to enable posted
mode in this case. Hence, for the timer used for kernel clock-events,
posted mode is enabled by overriding the errata for devices that are
impacted by this defect.

For drivers using the timers that do not read the counter or capture
registers and wish to use posted mode, can override the errata and
enable posted mode by making the following function calls.

	__omap_dm_timer_override_errata(timer, OMAP_TIMER_ERRATA_I103_I767);
	__omap_dm_timer_enable_posted(timer);

Both dmtimers and watchdogs are impacted by this defect this patch only
implements the workaround for the dmtimer. Currently the watchdog driver
does not read the counter register and so no workaround is necessary.

Posted mode will be disabled for all OMAP2+ devices (including AM33xx)
using a GP timer as a clock-source timer to guarantee correct operation.
This is not necessary for OMAP24xx devices but the default clock-source
timer for OMAP24xx devices is the 32k-sync timer and not the GP timer
and so should not have any impact. This should be re-visited for future
devices if this errata is fixed.

Confirmed with Vaibhav Hiremath that this bug also impacts AM33xx
devices.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

For OMAP2+ devices, when using DMTIMERs for system timers (clock-events and
clock-source) the posted mode configuration of the timers is used. To allow
the compiler to optimise the functions for configuring and reading the system
timers, the posted flag variable is hard-coded with the value 1. To make it
clear that posted mode is being used add some definitions so that it is more
readable.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

For OMAP devices, the 32kHz counter is the default clock-source for the kernel.
However, this is not the only possible clock-source the kernel can use for OMAP
devices.

When booting with device-tree, if the 32kHz counter is the desired clock-source
for the kernel, then parse the device-tree blob to ensure that the counter is
present and if so map memory for the counter using the device-tree of_iomap()
function so we are no longer reliant on the OMAP HWMOD framework to do this for
us.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>

In order to add device-tree support to the timer driver the following changes
were made ...

1. Allocate system timers (used for clock-events and clock-source) based upon
   timer properties rather than using an hard-coded timer instance ID. To allow
   this a new helper function called omap_dmtimer_find_by_property() has been
   added for finding a timer with the particular properties in the device-tree
   blob. Please note that this is an internal helper function for system timers
   only to find a timer in the device-tree blob. This cannot be used by device
   drivers, another API has been added for that (see below). Timers that are
   allocated for system timers are dynamically disabled at boot time by adding
   a status property with the value "disabled" to the timer's device-tree node.

   Please note that when allocating system timers we now pass a timer ID and
   timer property. The timer ID is only be used for allocating a timer when
   booting without device-tree. Once device-tree migration is complete, all
   the timer ID references will be removed.

2. System timer resources (memory and interrupts) are directly obtained from
   the device-tree timer node when booting with device-tree, so that system
   timers are no longer reliant upon the OMAP HWMOD framework to provide these
   resources.

3. If DT blob is present, then let device-tree create the timer devices
   dynamically.

4. When device-tree is present the "id" field in the platform_device structure
   (pdev->id) is initialised to -1 and hence cannot be used to identify a timer
   instance. Due to this the following changes were made ...
   a). The API omap_dm_timer_request_specific() is not supported when using
       device-tree, because it uses the device ID to request a specific timer.
       This function will return an error if called when device-tree is present.
       Users of this API should use omap_dm_timer_request_by_cap() instead.
   b). When removing the DMTIMER driver, the timer "id" was used to identify the
       timer instance. The remove function has been modified to use the device
       name instead of the "id".

5. When device-tree is present the platform_data structure will be NULL and so
   check for this.

6. The OMAP timer device tree binding has the following optional parameters ...
   a). ti,timer-alwon  --> Timer is in an always-on power domain
   b). ti,timer-dsp    --> Timer can generate an interrupt to the on-chip DSP
   c). ti,timer-pwm    --> Timer can generate a PWM output
   d). ti,timer-secure --> Timer is reserved on a secure OMAP device
   Search for the above parameters and set the appropriate timer attribute
   flags.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>