Commit Graph

87 Commits

Author SHA1 Message Date
Paul Walmsley
435699db6a OMAP2+ clock: clean up clkt_clksel.c
This patch cleans up arch/arm/mach-omap2/clkt_clksel.c.  It:

- makes several functions static that are not called outside the file;

- adds documentation;

- makes some code paths easier to read (hopefully), by breaking up
  compound statements and removing redundant checks;

- converts some pr_err()s that indicate clock tree data problems into WARN()s,
  so they are more likely to be noticed;

- and moves omap2_clk_round_rate() back into mach-omap2/clock.c, its proper
  home, since it is not clksel-specific.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-05-20 12:31:06 -06:00
Paul Walmsley
30962d9d0c OMAP2+ clock: revise omap2_clk_{disable,enable}()
Simplify the code in the omap2_clk_disable() and omap2_clk_enable()
functions, reducing levels of indentation.  This makes the code easier
to read.  Add some additional debugging pr_debug()s here also to help
others understand what is going on.

Revise the omap2_clk_disable() logic so that it now attempts to
disable the clock's clockdomain before recursing up the clock tree.
Simultaneously, ensure that omap2_clk_enable() is called on parent
clocks first, before enabling the clockdomain.  This ensures that a
parent clock's clockdomain is enabled before the child clock's
clockdomain.  These sequences should be the inverse of each other.

Revise the omap2_clk_enable() logic so that it now cleans up after
itself upon encountering an error.  Previously, an error enabling a
parent clock could have resulted in inconsistent usecounts on the
enclosing clockdomain.

Remove the trivial _omap2_clk_disable() and _omap2_clk_enable() static
functions, and replace it with the clkops calls that they were
executing.

For all this to work, the clockdomain omap2_clkdm_clk_enable() and
omap2_clkdm_clk_disable() code must not return an error on clockdomains
without CLKSTCTRL registers; so modify those functions to simply return 0
in that case.

While here, add some basic kerneldoc documentation on both functions,
and get rid of some old non-CodingStyle-compliant comments that have
existed since the dawn of time (at least, the OMAP clock framework's
time).

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
2010-02-24 17:45:16 -07:00
Paul Walmsley
4d30e82c26 OMAP2/3 clock: combine OMAP2 & 3 boot-time MPU rate change code
The OMAP2 and OMAP3 boot-time MPU rate change code is almost
identical.  Merge them into mach-omap2/clock.c, and add kerneldoc
documentation.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-02-24 17:45:15 -07:00
Paul Walmsley
8c34974ab0 OMAP2 clock: drop DELAYED_APP clock flag
All of the clocks that are marked with DELAYED_APP are changed as part
of the virt_prcm_set OPP virtual clock.  On 24xx, these clocks all
need to be changed as part of a group to keep the clock tree
functional - hence the need for the VALID_CONFIG bit, which is not
present on later OMAPs.  These clocks should not be rate-changed
independently.  So prevent these clocks from being changed
independently by dropping their .round_rate and .set_rate function
pointers.  It then turns out that the DELAYED_APP clock flag is no
longer useful, so drop it and the associated code and renumber the
clock flags.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
2010-02-24 12:29:42 -07:00
Paul Walmsley
657ebfadc1 OMAP3/4 clock: split into per-chip family files
clock34xx_data.c now contains data for the OMAP34xx family, the
OMAP36xx family, and the OMAP3517 family, so rename it to
clock3xxx_data.c.  Rename clock34xx.c to clock3xxx.c, and move the
chip family-specific clock functions to clock34xx.c, clock36xx.c, or
clock3517.c, as appropriate.  So now "clock3xxx.*" refers to the OMAP3
superset.

The main goal here is to prepare to compile chip family-specific clock
functions only for kernel builds that target that chip family.  To get to
that point, we also need to add CONFIG_SOC_* options for those other
chip families; that will be done in future patches, planned for 2.6.35.

OMAP4 is also affected by this.  It duplicated the OMAP3 non-CORE DPLL
clkops structure.  The OMAP4 variant of this clkops structure has been
removed, and since there was nothing else currently in clock44xx.c, it
too has been removed -- it can always be added back later when there
is some content for it.  (The OMAP4 clock autogeneration scripts have been
updated accordingly.)

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoît Cousson <b-cousson@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Ranjith Lohithakshan <ranjithl@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
2010-02-24 12:16:15 -07:00
Paul Walmsley
1a3377176b OMAP2 clock: drop CONFIG_PARTICIPANT clock flag
It turns out that the only purpose of the CONFIG_PARTICIPANT clock
flag is to prevent omap2_clk_set_rate() and omap2_clk_set_parent()
from being executed on clocks with that flag set.  The rate-changing
component can be more directly accomplished by dropping the .set_rate
and .round_rate function pointers from those CONFIG_PARTICIPANT struct
clks.  As far as the parent-changing component is concerned, it turns
out that none of the CONFIG_PARTICIPANT clocks have multiple parent
choices, so all that is necessary is for omap2_clk_set_parent() to
bail out early if the new parent is equal to the old parent.
Implement this change and get rid of the flag, which has always had a
confusing name (it appears to be a Kconfig option, falsely).

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
2010-02-24 12:15:04 -07:00
Ranjith Lohithakshan
419cc97d36 OMAP2/3 clock: Extend find_idlest() to pass back idle state value
Current implementation defines clock idle state indicators based on the
cpu information (cpu_is_omap24xx() or cpu_is_omap34xx()) in a system wide
manner. This patch extends the find_idlest() function in clkops to pass
back the idle state indicator for that clock, thus allowing idle state
indicators to be defined on a per clock basis if required.

This is specifically needed on AM35xx devices as the new IPSS clocks
indicates the idle status (0 is idle, 1 is ready) in a way just
opposite to how its handled in OMAP3 (0 is ready, 1 is idle).

Signed-off-by: Ranjith Lohithakshan <ranjithl@ti.com>
[paul@pwsan.com: updated to apply after commit 98c45457 et seq.]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-02-24 12:05:54 -07:00
Paul Walmsley
69ecefca51 OMAP2/3/4 clock: combine all omap2_clk_functions
The struct clk_functions for OMAP2, 3, and 4 are all essentially the
same, so combine them.  This removes one multi-OMAP kernel impediment
and saves memory on multi-OMAP builds.

The stubs for omap2_clk_{init,exit}_cpufreq() code will removed once
the OPP layer code that's currently in Kevin's PM branch is merged.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
2010-01-26 20:13:04 -07:00
Paul Walmsley
4b1f76ed4f OMAP2 clock: move all static functions to the top of the file
Move static functions to the top of the file and ensure that their names
are prefixed with an underscore to conform with the practice in the newer
OMAP clock code files.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-01-26 20:13:04 -07:00
Paul Walmsley
df791b3ebf OMAP2/3/4 clock: move clksel clock functions into mach-omap2/clkt_clksel.c
Move all clksel-related clock functions from mach-omap2/clock.c to
mach-omap2/clkt_clksel.c.  This is intended to make the clock code
easier to understand, since all of the functions needed to manage
clksel clocks are now located in their own file, rather than being
mixed with other, unrelated functions.

Clock debugging is also now more finely-grained, since the DEBUG macro
can now be defined for clksel clocks alon.  This should reduce
unnecessary console noise when debugging.

Also, if at some future point the mach-omap2/ directory is split
into OMAP2/3/4 variants, this clkt file can be moved to the plat-omap/
directory to be shared.

Thanks to Alexander Shishkin <virtuoso@slind.org> for his comments to
improve the patch description.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Alexander Shishkin <virtuoso@slind.org>
2010-01-26 20:13:04 -07:00
Paul Walmsley
0b96af6830 OMAP2/3/4 clock: move DPLL clock functions into mach-omap2/clkt_dpll.c
Move all DPLL-related clock functions from mach-omap2/clock.c to
mach-omap2/clkt_dpll.c.  This is intended to make the clock code
easier to understand, since all of the functions needed to manage
DPLLs are now located in their own file, rather than being mixed with
other, unrelated functions.

Clock debugging is also now more finely-grained, since the DEBUG macro
can now be defined for DPLLs alone.  This should reduce unnecessary
console noise when debugging.

Also, if at some future point the mach-omap2/ directory is split
into OMAP2/3/4 variants, this clkt file can be moved to the plat-omap/
directory to be shared.

Thanks to Alexander Shishkin <virtuoso@slind.org> for his comments to
improve the patch description.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Alexander Shishkin <virtuoso@slind.org>
2010-01-26 20:13:03 -07:00
Abhijit Pagare
bf98540106 ARM: OMAP4 clock framework: Remove the checks preventing OMAP4 clockdomain validation
The clockdomain related code being in place, it is not necessary to have
some part of the clock code commented out. This would help the validation of
the clockdomain functions using the clock level interfaces.

Signed-off-by: Abhijit Pagare <abhijitpagare@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-01-26 20:12:58 -07:00
Paul Walmsley
e9b98f6040 OMAP clock: make the fixed divisor clock code available for all OMAPs
One of the OMAP1 clocks can use the fixed divisor recalculation code
introduced in the OMAP2 clock code, so rename the
omap2_fixed_divisor_recalc() function to omap_fixed_divisor_recalc()
and make it available to all OMAPs.  A followup patch converts the OMAP1
clock.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-01-26 20:12:57 -07:00
Rajendra Nayak
911bd7395c ARM: OMAP4: PM: Add init api for DPLL nodes
An api at init for all dpll nodes seem to be
needed to reparent the dpll clk node to its
bypass clk in case the dpll is in bypass.
If not done this causes sequencing issues at init
during propogate_rate.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoit Cousson <b-cousson@ti.com>
2009-12-11 17:00:47 -07:00
Rajendra Nayak
16975a79c8 ARM: OMAP4: PM: Add support for OMAP4 dpll api's
Most of the dpll api's from dpll.c are reused for OMAP4.
This patch does extend a few api's for OMAP4 support.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoit Cousson <b-cousson@ti.com>
2009-12-11 17:00:46 -07:00
Rajendra Nayak
d79b126724 ARM: OMAP4: PM: Add dummy hooks for OMAP4 dpll api's
This patch adds dummy hooks for OMAP4 dpll api's. Removes
dummy hooks for clkdev api's and enables CLKDEV
for OMAP4.
Also comments clockdomain calls from within the clock
framework as its not supported yet for OMAP4.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoit Cousson <b-cousson@ti.com>
2009-12-11 17:00:46 -07:00
Tony Lindgren
ce491cf854 omap: headers: Move remaining headers from include/mach to include/plat
Move the remaining headers under plat-omap/include/mach
to plat-omap/include/plat. Also search and replace the
files using these headers to include using the right path.

This was done with:

#!/bin/bash
mach_dir_old="arch/arm/plat-omap/include/mach"
plat_dir_new="arch/arm/plat-omap/include/plat"
headers=$(cd $mach_dir_old && ls *.h)
omap_dirs="arch/arm/*omap*/ \
drivers/video/omap \
sound/soc/omap"
other_files="drivers/leds/leds-ams-delta.c \
drivers/mfd/menelaus.c \
drivers/mfd/twl4030-core.c \
drivers/mtd/nand/ams-delta.c"

for header in $headers; do
	old="#include <mach\/$header"
	new="#include <plat\/$header"
	for dir in $omap_dirs; do
		find $dir -type f -name \*.[chS] | \
			xargs sed -i "s/$old/$new/"
	done
	find drivers/ -type f -name \*omap*.[chS] | \
		xargs sed -i "s/$old/$new/"
	for file in $other_files; do
		sed -i "s/$old/$new/" $file
	done
done

for header in $(ls $mach_dir_old/*.h); do
	git mv $header $plat_dir_new/
done

Signed-off-by: Tony Lindgren <tony@atomide.com>
2009-10-20 09:40:47 -07:00
Peter 'p2' De Schrijver
fe617af716 OMAP: PM: Hook into PM counters
This patch modifies the clock, clockdomain and OMAP3 specific
powerdomain code to call the PM counter infrastructure whenever one or
more powerdomains might have changed state.

Signed-off-by: Peter 'p2' De Schrijver <peter.de-schrijver@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2009-09-02 15:08:23 -07:00
Paul Walmsley
72350b29a4 OMAP2/3 clock: split, rename omap2_wait_clock_ready()
Some OMAP2/3 hardware modules have CM_IDLEST attributes that are not
handled by the current omap2_wait_clock_ready() code.  In preparation
for patches that fix the unusual devices, rename the function
omap2_wait_clock_ready() to omap2_wait_module_ready() and split it
into three parts:

1. A clkops-specific companion clock return function (by default,
   omap2_clk_dflt_find_companion())

2. A clkops-specific CM_IDLEST register address and bit shift return
   function (by default, omap2_clk_dflt_find_idlest())

3. Code to wait for the CM to indicate that the module is ready
   (omap2_cm_wait_idlest())

Clocks can now specify their own custom find_companion() and find_idlest()
functions; used in subsequent patches.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-07-24 20:10:35 -06:00
Roel Kluin
2687069f3a OMAP2 clock/powerdomain: off by 1 error in loop timeout comparisons
with while (i++ < MAX_CLOCK_ENABLE_WAIT); i can reach MAX_CLOCK_ENABLE_WAIT + 1
after the loop, so if (i == MAX_CLOCK_ENABLE_WAIT) that's still success.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-06-19 19:09:32 -06:00
Tony Lindgren
88b6f7eb9b Merge branch 'omap-clock-upstream' of git://git.pwsan.com/linux-2.6 into for-next 2009-05-26 14:41:35 -07:00
Tony Lindgren
8e3bd351d1 ARM: OMAP2/3: Remove OMAP_PRM_REGADDR and OMAP2_PRM_BASE
Remove OMAP_PRM_REGADDR and use processor specific defines instead.

Also fold in a patch from Kevin Hilman to add _OFFSET #defines
for the PRCM registers to be used with the prm_[read|write]_* macros.
These are used extensively in the forthcoming OMAP PM support.

Also remove now unused OMAP2_PRM_BASE.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2009-05-25 11:26:42 -07:00
Artem Bityutskiy
0db4e82597 OMAP3 clock: lessen amount of noisy messages
On our system we see the following messages:

Disabling unused clock "gpt2_ick"
Disabling unused clock "gpt3_ick"
Disabling unused clock "gpt4_ick"
Disabling unused clock "gpt5_ick"
...

The messages have KERN_INFO level and if you have serial
console, they normally go there. I do not think it is good
idea to print that much stuff there. Moreover, messages
are not properly prefixed and for mortals it is not
immeadietly clear where they come from.

Let's give them debugging level instead.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
[paul@pwsan.com: trimmed debugging output in patch description]
2009-05-12 17:34:40 -06:00
Paul Walmsley
b7aee4bfa7 OMAP3 clock: use pr_debug() rather than pr_info() in some clock change code
The CORE DPLL M2 frequency change code should use pr_debug(), not
pr_info(), for its debug messages.  Same with
omap2_clksel_round_rate_div().  While here, convert a few printk(KERN_ERR ..
into pr_err().

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-05-12 17:27:10 -06:00
Russell King
14b6848bc0 Merge branch 'omap-clks3' into devel
Conflicts:

	arch/arm/mach-omap2/clock.c
2009-03-19 12:39:58 +00:00
Russell King
4da3782151 [ARM] omap: clk_set_parent: deny changing parent if clock is enabled
Richard Woodruff writes:
| The historic usage of this has been against single use leaf clocks
| (1st instance of gptimer).  When it was used it did:
|       clk_get()
|       clk_set_parent()
|       clk_enable()
|
| This usage was ok for that. Use on a disabled clock is needed.
|
| If there are multiple users on the clock or it is enabled there are
| problems.
|
| The call can still be unfriendly if 2 different drivers are using the
| clock with their own clock get/enable. It might be the function should
| return an error if usecount != 0 to stop surprises.  It is all around
| better if the parenting is done when the clock is off.

This is a good reason to ensure that the clock is not enabled when
clk_set_parent() is called.

Acked-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-03-03 13:08:18 +00:00
Russell King
c0bf31320d [ARM] omap: add support for bypassing DPLLs
This roughly corresponds with OMAP commits: 7d06c48, 3241b19,
88b5d9b, 18a5500, 9c909ac, 5c6497b, 8b1f0bd, 2ac1da8.

For both OMAP2 and OMAP3, we note the reference and bypass clocks in
the DPLL data structure.  Whenever we modify the DPLL rate, we first
ensure that both the reference and bypass clocks are enabled.  Then,
we decide whether to use the reference and DPLL, or the bypass clock
if the desired rate is identical to the bypass rate, and program the
DPLL appropriately.  Finally, we update the clock's parent, and then
disable the unused clocks.

This keeps the parents correctly balanced, and more importantly ensures
that the bypass clock is running whenever we reprogram the DPLL.  This
is especially important because the procedure for reprogramming the DPLL
involves switching to the bypass clock.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-19 17:28:30 +00:00
Russell King
41f3103fcf [ARM] omap: fix clock reparenting in omap2_clk_set_parent()
When changing the parent of a clock, it is necessary to keep the
clock use counts balanced otherwise things the parent state will
get corrupted.  Since we already disable and re-enable the clock,
we might as well use the recursive versions instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-19 13:25:16 +00:00
Russell King
abf239657b [ARM] omap: fix _omap2_clksel_get_src_field()
_omap2_clksel_get_src_field() was returning the first entry which was
either the default _or_ applicable to the SoC.  This is wrong - we
should be returning the first default which is applicable to the SoC.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-14 13:25:38 +00:00
Russell King
9132f1b453 [ARM] omap: fix omap2_divisor_to_clksel() error return value
The error checks for omap2_divisor_to_clksel() and comment disagree with
the actual value returned on error.  Fix this to return the correct error
value.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-14 13:24:10 +00:00
Russell King
8b9dbc16d4 [ARM] omap: arrange for clock recalc methods to return the rate
linux-omap source commit 33d000c99ee393fe2042f93e8422f94976d276ce
introduces a way to "dry run" clock changes before they're committed.
However, this involves putting logic to handle this into each and
every recalc function, and unfortunately due to the caching, led to
some bugs.

Solve both of issues by making the recalc methods always return the
clock rate for the clock, which the caller decides what to do with.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-14 09:59:21 +00:00
Russell King
8263e5b31e [ARM] omap: fix clockdomain enable/disable ordering
Based on a patch from Paul Walmsley <paul@pwsan.com>:

 omap2_clk_enable() should enable a clock's clockdomain before
 attempting to enable its parent clock's clockdomain.  Similarly, in
 the unlikely event that the parent clock enable fails, the clockdomain
 should be disabled.

 linux-omap source commit is 6d6e285e5a7912b1ea68fadac387304c914aaba8.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:46 +00:00
Russell King
a7f8c599c5 [ARM] omap: fix usecount decrement bug
Based upon a patch from Paul Walmsley <paul@pwsan.com>:

 If _omap2_clk_enable() fails, the clock's usecount must be decremented
 by one no matter whether the clock has a parent or not.

but reorganised a bit.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:46 +00:00
Paul Walmsley
f11fda6a91 [ARM] OMAP2/3 clock: convert remaining MPU barriers into OCP barriers
Several parts of the OMAP2/3 clock code use wmb() to try to ensure
that the hardware write completes before continuing.  This approach is
problematic: wmb() only ensures that the write leaves the ARM.  It
does not ensure that the write actually reaches the endpoint device.
The endpoint device in this case - either the PRM, CM, or SCM - is
three interconnects away from the ARM - and the final interconnect is
low-speed.  And the OCP interconnects will post the write, and who
knows how long that will take to complete.  So the wmb() is not what
we want.  Worse, the wmb() is indiscriminate; it causes the ARM to
flush any other unrelated buffered writes and wait for the local
interconnect to acknowledge them - potentially very expensive.

Fix this by converting the wmb()s into readbacks of the same PRM/CM/SCM
register.  Since the PRM/CM/SCM devices use a single OCP thread, this
will cause the MPU to block while waiting for posted writes to that device
to complete.

linux-omap source commit is 260f5487848681b4d8ea7430a709a601bbcb21d1.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:45 +00:00
Paul Walmsley
439764cc18 [ARM] OMAP2xxx clock: consolidate DELAYED_APP clock commits; fix barrier
Consolidate the commit code for DELAYED_APP clocks into a subroutine,
_omap2xxx_clk_commit().  Also convert the MPU barrier wmb() into an
OCP barrier, since with an MPU barrier, we have no guarantee that the
write actually reached the endpoint device.

linux-omap source commit is 0f5bdb736515801b296125d16937a21ff7b3cfdc.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:44 +00:00
Paul Walmsley
de07fedd79 [ARM] OMAP2/3 clock: don't use a barrier after clk_disable()
clk_disable() previously used an ARM barrier, wmb(), to try to ensure
that the hardware write completed before continuing.  There are some
problems with this approach.

The first problem is that wmb() only ensures that the write leaves the
ARM -- not that it actually reaches the endpoint device.  In this
case, the endpoint device - either the PRM, CM, or SCM - is three
interconnects away from the ARM, and the final interconnect is
low-speed.  And the OCP interconnects will post the write, who knows
how long that will take to complete.  So the wmb() is not really what
we want.

Worse, the wmb() is indiscriminate; it will cause the ARM to flush any
other unrelated buffered writes and wait for the local interconnect to
acknowledge them - potentially very expensive.

This first problem could be fixed by doing a readback of the same PRM/CM/SCM
register.  Since these devices use a single OCP thread, this will cause the
MPU to wait for the write to complete.

But the primary problem is a conceptual one: clk_disable() should not
need any kind of barrier.  clk_enable() needs one since device driver
code must not access a device until its clocks are known to be
enabled.  But clk_disable() has no such restriction.

Since blocking the MPU on a PRM/CM/SCM write can be a very
high-latency operation - several hundred MPU cycles - it's worth
avoiding this barrier if possible.

linux-omap source commit is f4aacad2c0ed1055622d5c1e910befece24ef0e2.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:42 +00:00
Russell King
3f0a820c4c [ARM] omap: create a proper tree of clocks
Traditionally, we've tracked the parent/child relationships between
clk structures by setting the child's parent member to point at the
upstream clock.  As a result, when decending the tree, we have had
to scan all clocks to find the children.

Avoid this wasteful scanning by keeping a list of the clock's children.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:42 +00:00
Tero Kristo
8463e20a58 [ARM] OMAP3: PM: Make sure clk_disable_unused() order is correct
Current implementation will disable clocks in the order defined in clock34xx.h,
at least DPLL4_M2X2 will hang in certain cases (and prevent retention / off)
if clocks are not disabled in correct order. This patch makes sure the parent
clocks will be active when disabling a clock.

linux-omap source commit is 672680063420ef8c8c4e7271984bb9cc08171d29.

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:40 +00:00
Paul Walmsley
f8de9b2c45 [ARM] OMAP2 SDRC: move mach-omap2/memory.h into mach/sdrc.h
Move the contents of the arch/arm/mach-omap2/memory.h file to the
existing mach/sdrc.h file, and remove memory.h.  Modify files which
include memory.h to include asm/arch/sdrc.h instead.

linux-omap source commit is e7ae2d89921372fc4b9712a32cc401d645597807.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:38 +00:00
Paul Walmsley
ee1eec3634 [ARM] OMAP2/3 clock: clean up mach-omap2/clock.c
This patch rolls up several cleanup patches.

1. Some unnecessarily verbose variable names are used in several clock.c
functions; clean these up per CodingStyle.

2. Remove omap2_get_clksel() and just use clk->clksel_reg and
clk->clksel_mask directly.

3. Get rid of void __iomem * usage in omap2_clksel_get_src_field.
Prepend the function name with an underscore to highlight that it is a
static function.

linux-omap source commits are 7fa95e007ea2f3c4d0ecd2779d809756e7775894,
af0ea23f1ee4a5bea3b026e38761b47089f9048a, and
91c0c979b47c44b08f80e4f8d4c990fb158d82c4.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:36 +00:00
Paul Walmsley
95f538ac37 [ARM] OMAP3 clock: avoid invalid FREQSEL values during DPLL rate rounding
The DPLL FREQSEL jitter correction bits are set based on a table in
the 34xx TRM, Table 4-38, according to the DPLL's internal clock
frequency "Fint."  Several Fint frequency ranges are missing from this
table.  Previously, we allowed these Fint frequency ranges to be
selected in the rate rounding code, but did not change the FREQSEL bits.
Correspondence with the OMAP hardware team indicates that Fint values
not in the table should not be used.  So, prevent them from being
selected during DPLL rate rounding.  This removes warnings and also
can prevent the chip from locking up.

The first pass through the rate rounding code will update the DPLL max
and min dividers appropriately, so later rate rounding passes will run
faster than the first.

Peter de Schrijver <peter.de-schrijver@nokia.com> put up with several
test cycles of this patch - thanks Peter.

linux-omap source commit is f9c1b82f55b60fc39eaa6e7aa1fbe380c0ffe2e9.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Peter de Schrijver <peter.de-schrijver@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:35 +00:00
Paul Walmsley
85a5f78d2b [ARM] OMAP3 clock: optimize DPLL rate rounding algorithm
The previous DPLL rate rounding algorithm counted the divider (N) down
from the maximum to 1.  Since we currently use a broad DPLL rate
tolerance, and lower N values are more power-efficient, we can often
bypass several iterations through the loop by counting N upwards from
1.

Peter de Schrijver <peter.de-schrijver@nokia.com> put up with several
test cycles of this patch - thanks Peter.

linux-omap source commit is 6f6d82bb2f80fa20a841ac3e95a6f44a5a156188.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Peter de Schrijver <peter.de-schrijver@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:34 +00:00
Paul Walmsley
b324504098 [ARM] OMAP3 clock: remove unnecessary dpll_data dereferences
Remove some clutter from omap2_dpll_round_rate().

linux-omap source commit is 4625dceb8583c02a6d67ededc9f6a8347b6b8cb7.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:34 +00:00
Paul Walmsley
fecb494bee [ARM] OMAP: Fix sparse, checkpatch warnings in OMAP2/3 PRCM/PM code
Fix sparse & checkpatch warnings in OMAP2/3 PRCM & PM code.  This mostly
consists of:

- converting pointer comparisons to integers in form similar to
  (ptr == 0) to the standard idiom (!ptr)

- labeling a few non-static private functions as static

- adding prototypes for *_init() functions in the appropriate header
  files, and getting rid of the corresponding open-coded extern
  prototypes in other C files

- renaming the variable 'sclk' in mach-omap2/clock.c:omap2_get_apll_clkin
  to avoid shadowing an earlier declaration

Clean up checkpatch issues.  This mostly involves:

- converting some asm/ includes to linux/ includes

- cleaning up some whitespace

- getting rid of braces for conditionals with single following statements

Also take care of a few odds and ends, including:

- getting rid of unlikely() and likely() - none of this code is particularly
  fast-path code, so the performance impact seems slim; and some of those
  likely() and unlikely() indicators are probably not as accurate as the
  ARM's branch predictor

- removing some superfluous casts

linux-omap source commit is 347df59f5d20fdf905afbc26b1328b0e28a8a01b.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:24 +00:00
Russell King
9a5fedac18 [ARM] omap: move propagate_rate() calls into generic omap clock code
propagate_rate() is recursive, so it makes sense to minimise the
amount of stack which is used for each recursion.  So, rather than
recursing back into it from the ->recalc functions if RATE_PROPAGATES
is set, do that test at the higher level.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:11 +00:00
Russell King
c6af450852 [ARM] omap: move clock propagation into core omap clock code
Move the clock propagation calls for set_parent and set_rate into
the core omap clock code, rather than having these calls scattered
throughout the OMAP1 and OMAP2 implementations.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 17:50:10 +00:00
Russell King
c1168dc31d [ARM] omap: don't use clkops_omap2_dflt_wait for non-ICLK/FCLK clocks
The original code in omap2_clk_wait_ready() used to check the low 8
bits to determine whether they were within the FCLKEN or ICLKEN
registers.  Specifically, the test is satisfied when these offsets
are used:

 CM_FCLKEN, CM_FCLKEN1, CM_CLKEN, OMAP24XX_CM_FCLKEN2, CM_ICLKEN,
 CM_ICLKEN1, CM_ICLKEN2, CM_ICLKEN3, OMAP24XX_CM_ICLKEN4
 OMAP3430_CM_CLKEN_PLL, OMAP3430ES2_CM_CLKEN2

If one of these offsets isn't used, omap2_clk_wait_ready() merely
returns without doing anything.  So we should use the non-wait clkops
version instead and eliminate that conditional.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 11:38:41 +00:00
Russell King
bc51da4ee4 [ARM] omap: eliminate unnecessary conditionals in omap2_clk_wait_ready
Rather than employing run-time tests in omap2_clk_wait_ready() to
decide whether we need to wait for the clock to become ready, we
can set the .ops appropriately.

This change deals with the OMAP24xx and OMAP34xx conditionals only.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 11:38:40 +00:00
Russell King
b36ee72420 [ARM] omap: add default .ops to all remaining OMAP2 clocks
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 11:38:40 +00:00
Russell King
57137181e3 [ARM] omap: kill PARENT_CONTROLS_CLOCK
PARENT_CONTROLS_CLOCK just makes enable/disable no-op, and is
functionally an alias for ALWAYS_ENABLED.  This can be handled
in the same way, using clkops_null.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-08 11:38:39 +00:00