Commit Graph

207 Commits

Author SHA1 Message Date
Masahiro Yamada
470b5e2f97 clk: simplify clk_fetch_parent_index() function
The clk_core_get_parent_by_index can be used as a helper function
to simplify the implementation of clk_fetch_parent_index().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:16 -08:00
Masahiro Yamada
508f884a66 clk: make sure parent is not NULL in clk_fetch_parent_index()
If parent is given with NULL, clk_fetch_parent_index() could return
a positive index value.

Currently, parent is checked by the callers of this function, but
it would be safer to do it in this function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:15 -08:00
Masahiro Yamada
0e8f6e499e clk: walk the orphan clock list more simply
This loop can be much simpler. If a new parent is available for
orphan clocks, __clk_init_parent(orphan) can detect it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:14 -08:00
Masahiro Yamada
858d588156 clk: avoid circular clock topology
Currently, clk_register() never checks a circular parent looping,
but clock providers could register such an insane clock topology.
For example, "clk_a" could have "clk_b" as a parent, and vice versa.
In this case, clk_core_reparent() creates a circular parent list
and __clk_recalc_accuracies() calls itself recursively forever.

The core infrastructure should be kind enough to bail out, showing
an appropriate error message in such a case.  This helps to easily
find a bug in clock providers.  (uh, I made such a silly mistake
when I was implementing my clock providers first.  I was upset
because the kernel did not respond, without any error message.)

This commit adds a new helper function, __clk_is_ancestor().  It
returns true if the second argument is a possible ancestor of the
first one.  If a clock core is a possible ancestor of itself, it
would make a loop when it were registered.  That should be detected
as an error.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:13 -08:00
Masahiro Yamada
5146e0b059 clk: simplify __clk_init_parent()
The translation from the index into clk_core is done by
clk_core_get_parent_by_index().  The if-block for num_parents == 1
case is duplicating the code in the clk_core_get_parent_by_index().

Drop the "if (num_parents == 1)" from the special case.  Instead,
set the index to zero if .get_parent() is missing.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:53:10 -08:00
Masahiro Yamada
3c8e77dd20 clk: move checking .get_parent to __clk_core_init()
The .get_parent is mandatory for multi-parent clocks.  Move the check
to __clk_core_init(), like other callback checkings.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
[sboyd@codeaurora.org: Squashed in error path handling, fix typos
in commit message]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02 11:52:06 -08:00
Masahiro Yamada
c44fccb5f7 clk: replace pr_warn() with pr_err() for fatal cases
These three cases let clk_register() fail.  They should be considered
as error messages.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:59 -08:00
Masahiro Yamada
3c436bf95a clk: drop the initial core->parents look-ups from __clk_core_init()
The core->parents is a cache to save expensive clock parent look-ups.
It will be filled as needed later.  We do not have to do it here.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:54 -08:00
Masahiro Yamada
88cfbef2ac clk: simplify clk_core_get_parent_by_index()
Drop the "if (!core->parents)" case and refactor the function a bit
because core->parents is always allocated.  (Strictly speaking, it is
ZERO_SIZE_PTR if core->num_parents == 0, but such a case is omitted
by the if-conditional above.)

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:50 -08:00
Masahiro Yamada
176d11690b clk: move core->parents allocation to clk_register()
Currently, __clk_core_init() allows failure of the kcalloc() for the
core->parents.  So, clk_fetch_parent_index() and __clk_init_parent()
also try to allocate core->parents in case it has not been allocated
yet.  Scattering memory allocation here and there makes things
complicated.

Like other clk_core members, allocate core->parents in clk_register()
and let it fail in case of memory shortage.  If we cannot allocate
such a small piece of memory, the system is already insane.  There is
no point to postpone the memory allocation.

Also, allocate core->parents regardless of core->num_parents.  We want
it even if core->num_parents == 1 because clk_fetch_parent_index()
might be called against the clk_core with a single parent.

If core->num_parents == 0, core->parents is set to ZERO_SIZE_PTR. It
is harmless because no access happens to core->parents in such a case.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:46 -08:00
Masahiro Yamada
3a6e845451 clk: change sizeof(struct clk *) to sizeof(*core->parents)
Now, the clock parent is not "struct clk *", but "struct clk_core *".
Of course, the size of a pointer is always same, but strictly speaking,
sizeof(struct clk *) should be sizeof(struct clk_core *) here.

This mismatch happened when we split the structure into struct clk
and struct clk_core.  For the potential possibility of future renaming,
sizeof(*core->parents) would be better.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:43 -08:00
Masahiro Yamada
027f942ce4 clk: remove unnecessary !core->parents conditional
This if-block has been here since the introduction of the common
clock framework.  Now no clock drivers are statically initialized.
core->parent is always NULL at this point.  Drop the redundant
check and the confusing comment.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:39 -08:00
Masahiro Yamada
be45ebf25f clk: rename __clk_init() into __clk_core_init()
Now this function takes clk_core as its argument.  __clk_core_init()
would be more suitable for the name of this function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:36 -08:00
Masahiro Yamada
d35c80c248 clk: change the argument of __clk_init() into pointer to clk_core
The argument clk_user is used only for the clk_user->core.  The rest
of this function only takes care of clk_core.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:32 -08:00
Masahiro Yamada
d9e743408e clk: remove unused first argument of __clk_init()
The "struct device *dev" is not used at all in this function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-01 17:01:28 -08:00
Michael Turquette
a915e30dd2 Merge branch 'clk-rockchip' into clk-next 2015-12-23 13:08:56 -08:00
Heiko Stuebner
2eb8c7104c clk: add flag for clocks that need to be enabled on rate changes
Some clocks need to be enabled to accept rate changes. This patch adds a
new flag CLK_SET_RATE_UNGATE that lets clk_change_rate enable the clock
before trying to change the rate and disable it again afterwards.
This of course doesn't effect clocks that are already running at that
point, as their refcount will only temporarily increase.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-12-23 12:57:31 -08:00
Masahiro Yamada
8da411cc19 clk: let of_clk_get_parent_name() fail for invalid clock-indices
Currently, of_clk_get_parent_name() returns a wrong parent clock name
when "clock-indices" property exists and the target index is not
found in the property.  In this case, NULL should be returned.

For example,

        oscillator {
                compatible = "myclocktype";
                #clock-cells = <1>;
                clock-indices = <1>, <3>;
                clock-output-names = "clka", "clkb";
        };

        consumer {
                compatible = "myclockconsumer";
                clocks = <&oscillator 0>, <&oscillator 1>;
        };

Currently, of_clk_get_parent_name(consumer_np, 0) returns "clka"
(and of_clk_get_parent_name(consumer_np, 1) also returns "clka",
this is correct).   Because the "clock-indices" in the clock parent
does not contain <0>, of_clk_get_parent_name(consumer_np, 0) should
return NULL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-12-02 22:34:43 -08:00
Masahiro Yamada
198bb59493 clk: fix a typo in comment block of clk_notifier_register()
The word "cases" is doubled.  Keep decent forms for the following
lines.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-30 11:36:07 -08:00
Geert Uytterhoeven
3fe003f944 clk: Spelling s/derefing/dereferencing/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20 11:17:55 -08:00
Masahiro Yamada
c1de13574d clk: use IS_ERR_OR_NULL(hw) instead of !hw || IS_ERR(hw)
This minor refactoring does not change the function behavior.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20 09:20:54 -08:00
Masahiro Yamada
c736c4e11e clk: remove redundant negative index check in of_clk_get_parent_name()
This if-block can be dropped because the of_parse_phandle_with_args()
in the following line returns -EINVAL for negative index.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20 09:18:24 -08:00
Joachim Eastwood
be68bf8831 clk: Add clk_hw_is_enabled() for use by clk providers
Add clk_hw_is_enabled() to the provider APIs so clk providers can
use a struct clk_hw instead of a struct clk to check if a clk is
enabled or not.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-26 12:36:55 -07:00
Julia Lawall
6bc9d9d62c clk: add missing of_node_put
for_each_matching_node_and_match performs an of_node_get on each iteration,
so a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression e1,e2,e;
local idexpression np;
@@

 for_each_matching_node_and_match(np, e1, e2) {
   ... when != of_node_put(np)
       when != e = np
(
   return np;
|
+  of_node_put(np);
?  return ...;
)
   ...
 }
// </smpl>

Besides the problem identified by the semantic patch, this patch adds an
of_node_get in front of saving np in a field of parent, to account for the
fact that this value will be put on going on to the next element in the
iteration, and then adds of_node_puts in the two loops where the parent
pointer can be freed.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-21 16:16:32 -07:00
Geert Uytterhoeven
b76281cb97 clk: Make clk input parameter of __clk_get_name() const
When calling __clk_get_name() on a const clock:

    warning: passing argument 1 of '__clk_get_name' discards 'const' qualifier from pointer target type
    include/linux/clk-provider.h:613:13: note: expected 'struct clk *' but argument is of type 'const struct clk *'

__clk_get_name() does not modify the passed clock, hence make it const.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-16 11:56:19 -07:00
Geert Uytterhoeven
7e96353c3f clk: Use %u to format unsigned int in of_clk_src_onecell_get()
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-16 11:49:01 -07:00
Stephen Boyd
0a4807c2f9 clk: Make of_clk_get_parent_name() robust with #clock-cells = 1
If a clock provider has #clock-cells = 1 and we call
of_clk_get_parent_name() on it we may end up returning the name
of the provider node if the provider doesn't have a
clock-output-names property. This doesn't make sense, especially
when you consider that calling of_clk_get_parent_name() on such a
node with different indices will return the same name each time.

Let's try getting the clock from the framework via of_clk_get()
instead, and only fallback to the node name if we have a provider
with #clock-cells = 0. This way, we can't hand out the same name
for different clocks when we don't actually know their names.

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-15 16:17:03 -07:00
Stephen Boyd
ab5c342992 Merge branch 'clk-fixes' into clk-next
* clk-fixes:
  drivers: clk: st: Rename st_pll3200c32_407_c0_x into st_pll3200c32_cx_x
  clk: check for invalid parent index of orphans in __clk_init()
2015-09-17 12:28:41 -07:00
Javier Martinez Canillas
90c53547fc clk: Remove unneeded semicolons
There are cleary typo errors so can be removed.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-09-17 11:15:14 -07:00
Mans Rullgard
9054a31d60 clk: check for invalid parent index of orphans in __clk_init()
If a mux clock is initialised (by hardware or firmware) with an
invalid parent, its ->get_parent() can return an out of range
index.  For example, the generic mux clock attempts to return
-EINVAL, which due to the u8 return type ends up a rather large
number.  Using this index with the parent_names[] array results
in an invalid pointer and (usually) a crash in the following
strcmp().

This patch adds a check for the parent index being in range,
ignoring clocks reporting invalid values.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Tested-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-09-16 15:35:18 -07:00
Dong Aisheng
c660b2ebb2 clk: remove duplicated code with __clk_set_parent_after
__clk_set_parent_after() actually used the second argument then we
could put this duplicate logic in there and call it with a different
order of arguments in the success vs. error paths in this function.

Cc: Mike Turquette <mturquette@linaro.org>
Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:49:13 -07:00
Stephen Boyd
e7df6f6e21 clk: Constify clk_hw argument to provider APIs
We don't modify the clk_hw argument in these functions, so it's
safe to mark it as const.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:49:11 -07:00
Stephen Boyd
fc4a05d4b0 clk: Remove unused provider APIs
Remove these APIs now that we've converted all users to the
replacement struct clk_hw based versions.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:49:02 -07:00
Stephen Boyd
1a9c069cb2 clk: Add clk_hw_*() APIs for use by clk providers
clk providers shouldn't need to use the consumer APIs (clk.h).
Add provider APIs to replace the __clk_*() APIs that take a
struct clk_hw as their first argument instead of a struct clk.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:48:42 -07:00
Heiko Stuebner
e6500344ed clk: track the orphan status of clocks and their children
While children of orphan clocks are not carried in the orphan-list itself,
they're nevertheless orphans in their own right as they also don't have an
input-rate available. To ease tracking if a clock is an orphan or has an
orphan in its parent path introduce an orphan field into struct clk and
update it and the fields in child-clocks when a clock gets added or removed
from the orphan-list.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Alex Elder <elder@linaro.org>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: kernel@pengutronix.de
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Chao Xie <chao.xie@marvell.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Georgi Djakov <georgi.djakov@linaro.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Barry Song <baohua@kernel.org>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Gabriel FERNANDEZ <gabriel.fernandez@st.com>
Cc: emilio@elopez.com.ar
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Michal Simek <michal.simek@xilinx.com>
[sboyd@codeaurora.org: s/clk/core/ in new function]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-12 00:59:18 -07:00
Stephen Boyd
a57aa18539 clk: Silence warnings about lock imbalances
The recursive spinlock implementation trips up sparse and it
complains that these functions have lock imbalances. That isn't
really true though, so add some __acquires() and __releases()
information so that sparse is quiet.

drivers/clk/clk.c:116:22: warning: context imbalance in 'clk_enable_lock' - wrong count at exit
drivers/clk/clk.c:141:9: warning: context imbalance in 'clk_enable_unlock' - unexpected unlock

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28 11:59:30 -07:00
Stephen Boyd
9cfad9bc47 Merge branch 'cleanup-clk-h-includes' into clk-next
* cleanup-clk-h-includes: (62 commits)
  clk: Remove clk.h from clk-provider.h
  clk: h8300: Remove clk.h and clkdev.h includes
  clk: at91: Include clk.h and slab.h
  clk: ti: Switch clk-provider.h include to clk.h
  clk: pistachio: Include clk.h
  clk: ingenic: Include clk.h
  clk: si570: Include clk.h
  clk: moxart: Include clk.h
  clk: cdce925: Include clk.h
  clk: Include clk.h in clk.c
  clk: zynq: Include clk.h
  clk: ti: Include clk.h
  clk: sunxi: Include clk.h and remove unused clkdev.h includes
  clk: st: Include clk.h
  clk: qcom: Include clk.h
  clk: highbank: Include clk.h
  clk: bcm: Include clk.h
  clk: versatile: Remove clk.h and clkdev.h includes
  clk: ux500: Remove clk.h and clkdev.h includes
  clk: tegra: Properly include clk.h
  ...
2015-07-28 11:59:09 -07:00
Stephen Boyd
9783c0d985 clk: Allow providers to configure min/max rates
clk providers are using the consumer APIs to set min/max rates on
the clock they're providing. To encourage clk providers to move
away from the consumer APIs, add a provider API to set the
min/max rate of a clock. The assumption is that this is done
before the clock can be requested via clk_get() and that the
clock rate is already within the boundaries of the min/max that's
configured.

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28 11:58:50 -07:00
Stephen Boyd
19aab27308 Merge branch 'clk-determine-rate-struct' into clk-next
* clk-determine-rate-struct:
  clk: fix some determine_rate implementations
  clk: change clk_ops' ->determine_rate() prototype
2015-07-28 11:51:30 -07:00
Boris Brezillon
57d866e606 clk: fix some determine_rate implementations
Some determine_rate implementations are not returning an error
when they failed to adapt the rate according to the rate request.
Fix them so that they return an error instead of silently
returning 0.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Tony Lindgren <tony@atomide.com>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: "Emilio López" <emilio@elopez.com.ar>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Tero Kristo <t-kristo@ti.com>
CC: Peter De Schrijver <pdeschrijver@nvidia.com>
CC: Prashant Gaikwad <pgaikwad@nvidia.com>
CC: Stephen Warren <swarren@wwwdotorg.org>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Alexandre Courbot <gnurou@gmail.com>
CC: linux-doc@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-omap@vger.kernel.org
CC: linux-mips@linux-mips.org
CC: linux-tegra@vger.kernel.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-27 18:13:32 -07:00
Boris Brezillon
0817b62cc0 clk: change clk_ops' ->determine_rate() prototype
Clock rates are stored in an unsigned long field, but ->determine_rate()
(which returns a rounded rate from a requested one) returns a long
value (errors are reported using negative error codes), which can lead
to long overflow if the clock rate exceed 2Ghz.

Change ->determine_rate() prototype to return 0 or an error code, and pass
a pointer to a clk_rate_request structure containing the expected target
rate and the rate constraints imposed by clk users.

The clk_rate_request structure might be extended in the future to contain
other kind of constraints like the rounding policy, the maximum clock
inaccuracy or other things that are not yet supported by the CCF
(power consumption constraints ?).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Tony Lindgren <tony@atomide.com>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: "Emilio López" <emilio@elopez.com.ar>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Tero Kristo <t-kristo@ti.com>
CC: Peter De Schrijver <pdeschrijver@nvidia.com>
CC: Prashant Gaikwad <pgaikwad@nvidia.com>
CC: Stephen Warren <swarren@wwwdotorg.org>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Alexandre Courbot <gnurou@gmail.com>
CC: linux-doc@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-omap@vger.kernel.org
CC: linux-mips@linux-mips.org
CC: linux-tegra@vger.kernel.org
[sboyd@codeaurora.org: Fix parent dereference problem in
__clk_determine_rate()]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
[sboyd@codeaurora.org: Folded in fix from Heiko for fixed-rate
clocks without parents or a rate determining op]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-27 18:12:01 -07:00
Stephen Boyd
3c37311730 clk: Include clk.h in clk.c
This file implements the clk API and so it should include clk.h
directly instead of indirectly including it through
clk-provider.h.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-20 11:11:30 -07:00
Stephen Boyd
2573a02aa5 clk: Move clk_provider_list to scope of function using it
The list isn't used after of_clk_init() is called, so we don't
need to keep an empty list around after init. Put the list on the
stack.

Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-07 17:20:05 -07:00
Stephen Boyd
2e3b19f137 clk: Check for allocation errors in of_clk_init()
Dan Carpenter reports that we don't check the allocation here for
failure. Add a failure check and free any previously allocated
providers from the clk_provider_list.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-07 17:20:03 -07:00
Michael Turquette
2cd7b04328 clk: tegra: Changes for v4.2-rc1
This contains the EMC clock driver that's been exhaustively reviewed and
 tested. It also includes a change to the clock core that allows a clock
 provider to perform low-level reparenting of clocks. This is required by
 the EMC clock driver because the reparenting needs to be done at a very
 specific point in time during the EMC frequency switch.
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Merge tag 'tegra-for-4.2-clk' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into clk-next

clk: tegra: Changes for v4.2-rc1

This contains the EMC clock driver that's been exhaustively reviewed and
tested. It also includes a change to the clock core that allows a clock
provider to perform low-level reparenting of clocks. This is required by
the EMC clock driver because the reparenting needs to be done at a very
specific point in time during the EMC frequency switch.
2015-06-20 13:29:48 -07:00
Michael Turquette
85e88fab13 Merge branch 'clk-exynos-cpu-clk' into clk-next
Folded into this merge commit is a build error fix: s/clk/core in
clk_change_rate due to the new struct clk_core
2015-06-20 13:26:40 -07:00
Bartlomiej Zolnierkiewicz
d8d919879e clk: add CLK_RECALC_NEW_RATES clock flag for Exynos cpu clock support
This flag is needed to fix the issue with wrong dividers being setup
by Common Clock Framework when using the new Exynos cpu clock support.

The issue happens because clk_core_set_rate_nolock()  calls
clk_calc_new_rates(clk, rate) before both pre/post clock notifiers have
a chance to run.  In case of Exynos cpu clock support pre/post clock
notifiers are registered for mout_apll clock which is a parent of armclk
cpu clock and dividers are modified in both pre and post clock notifier.
This results in wrong dividers values being later programmed by
clk_change_rate(top).  To workaround the problem CLK_RECALC_NEW_RATES
flag is added and it is set for mout_apll clock later so the correct
divider values are re-calculated after both pre and post clock notifiers
had run.

For example when using "performance" governor on Exynos4210 Origen board
the cpufreq-dt driver requests to change the frequency from 1000MHz to
1200MHz and after the change state of the relevant clocks is following:

Without use of CLK_GET_RATE_NOCACHE flag:

 fout_apll rate: 1200000000
         fout_apll_div_2 rate: 600000000
                 mout_clkout_cpu rate: 600000000
                         div_clkout_cpu rate: 600000000
                                 clkout_cpu rate: 600000000
         mout_apll rate: 1200000000
                 armclk rate: 1200000000
                 mout_hpm rate: 1200000000
                         div_copy rate: 300000000
                                 div_hpm rate: 300000000
                 mout_core rate: 1200000000
                         div_core rate: 1200000000
                                 div_core2 rate: 1200000000
                                         arm_clk_div_2 rate: 600000000
                                         div_corem0 rate: 300000000
                                         div_corem1 rate: 150000000
                                         div_periph rate: 300000000
                         div_atb rate: 300000000
                                 div_pclk_dbg rate: 150000000
                 sclk_apll rate: 1200000000
                         sclk_apll_div_2 rate: 600000000

With use of CLK_GET_RATE_NOCACHE flag:

 fout_apll rate: 1200000000
         fout_apll_div_2 rate: 600000000
                 mout_clkout_cpu rate: 600000000
                         div_clkout_cpu rate: 600000000
                                 clkout_cpu rate: 600000000
         mout_apll rate: 1200000000
                 armclk rate: 1200000000
                 mout_hpm rate: 1200000000
                         div_copy rate: 200000000
                                 div_hpm rate: 200000000
                 mout_core rate: 1200000000
                         div_core rate: 1200000000
                                 div_core2 rate: 1200000000
                                         arm_clk_div_2 rate: 600000000
                                         div_corem0 rate: 300000000
                                         div_corem1 rate: 150000000
                                         div_periph rate: 300000000
                         div_atb rate: 240000000
                                 div_pclk_dbg rate: 120000000
                 sclk_apll rate: 150000000
                         sclk_apll_div_2 rate: 75000000

Without this change cpufreq-dt driver showed ~10 mA larger energy
consumption when compared to cpufreq-exynos one when "performance"
cpufreq governor was used on Exynos4210 SoC based Origen board.

This issue was probably meant to be workarounded by use of
CLK_GET_RATE_NOCACHE and CLK_DIVIDER_READ_ONLY clock flags in
the original Exynos cpu clock patchset (in "[PATCH v12 6/6] clk:
samsung: remove unused clock aliases and update clock flags" patch)
but usage of these flags is not sufficient to fix the issue observed.

Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-06-20 12:17:41 -07:00
Maxime Coquelin
8c9a8a8f71 clk: Move debug_node field under DEBUG_FS flag in struct clk_core
The debug_node field is only used when DEBUG_FS config is selected,
so declare it only if DEBUG_FS is selected.

Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-06-10 14:21:22 -07:00
Dinh Nguyen
2e61dfb360 clk: of: helper for filling parent clock array and return num of parents
Sprinkled all through the platform clock drivers are code like this to
fill the clock parent array:

for (i = 0; i < num_parents; ++i)
	parent_names[i] = of_clk_get_parent_name(np, i);

The of_clk_parent_fill() will do the same as the code above, and while
at it, return the number of parents as well since the logic of the
function is to the walk the clock node to look for the parent.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
[sboyd@codeaurora.org: Fixed kernel-doc]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-06-05 18:10:33 -07:00
Shailendra Verma
a59a516398 clk: Fix typo in clk_register() comment
Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-20 15:44:32 -07:00