__clk_init() was renamed to __clk_core_init() but these comments
weren't updated.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

This reverts commit 858d5881.

Joachim reports that this commit breaks lpc18xx boot. This is
because the hardware has circular clk topology where PLLs can
feed into dividers and the same dividers can feed into the PLLs.
The hardware is designed this way so that you can choose to put
the divider before the PLL or after the PLL depending on what you
configure to be the parent of the divider and what you configure
to be the parent of the PLL.

So let's drop this patch for now because we have hardware that
actually has loops. A future patch could check for circular
parents when we change parents and fail the switch, but that's
probably best left to some debugging Kconfig option so that we
don't suffer the sanity checking cost all the time.
Reported-by: NJoachim Eastwood <manabian@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

Export symbol of_clk_get_from_provider so it can be used in
loadable kernel modules
Signed-off-by: NAndrew F. Davis <afd@ti.com>
Signed-off-by: NMichael Turquette <mturquette@baylibre.com>

Before commit b3d192d5121f ("clk: simplify __clk_init_parent()"),
__clk_init_parent() called .get_parent() only for multi-parent
clocks.  That commit changed the behavior to call .get_parent()
if available even for single-parent clocks and root clocks.

It turned out a problem because there are some single-parent clocks
that implement .get_parent() callback and return non-zero index.
The SOCFPGA clock is the case; the commit broke the SOCFPGA boards.

To keep the original behavior, invoke .get_parent() only when
num_parents is greater than 1.

Fixes: b3d192d5121f ("clk: simplify __clk_init_parent()")
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reported-by: NDinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

We don't use CLK_IS_ROOT but in a few places in the common clk
framework core. Let's replace those checks with a check for the
number of parents a clk has instead of the flag, freeing up one
flag for something else. We don't remove the flag yet so that
things keep building, but we'll remove it once all drivers have
removed their flag usage.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

If clock is already unregistered, it returns with holding lock.
It needs to be unlocked.
Signed-off-by: NInsu Yun <wuninsu@gmail.com>
[sboyd@codeaurora.org: Use goto instead]
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

If clk_fetch_parent_index() fails, p_rate is unused.  Move the
assignment after the error checking.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

The .get_parent is mandatory for multi-parent clocks.  Move the check
to __clk_core_init(), like other callback checkings.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
[sboyd@codeaurora.org: Squashed in error path handling, fix typos
in commit message]
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

These three cases let clk_register() fail.  They should be considered
as error messages.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

The "struct device *dev" is not used at all in this function.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NSjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: NSjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: NMichael Turquette <mturquette@baylibre.com>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

The word "cases" is doubled.  Keep decent forms for the following
lines.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

This minor refactoring does not change the function behavior.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NStephen Boyd <sboyd@codeaurora.org>

There are cleary typo errors so can be removed.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLeo Yan <leo.yan@linaro.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NMans Rullgard <mans@mansr.com>
Tested-by: NRhyland Klein <rklein@nvidia.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

__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: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDong Aisheng <aisheng.dong@freescale.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

We don't modify the clk_hw argument in these functions, so it's
safe to mark it as const.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

Remove these APIs now that we've converted all users to the
replacement struct clk_hw based versions.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>

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: NStephen Boyd <sboyd@codeaurora.org>

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: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NHeiko 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: NStephen Boyd <sboyd@codeaurora.org>