This patch adds helper functions to configure clock parents and rates
as specified through 'assigned-clock-parents', 'assigned-clock-rates'
DT properties for a clock provider or clock consumer device.
The helpers are now being called by the bus code for the platform, I2C
and SPI busses, before the driver probing and also in the clock core
after registration of a clock provider.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Define and export a new function clk_debugs_add_file which adds a file
to a existing clock's debugfs directory. This can be used by clock
providers to add debugfs entries which are not related to a specific clock
type. Examples include the ability to measure the rate of a clock. It can
also be used by modules to create new debugfs entries. This is useful if you
want to expose features for testing which can potentially cause system
instability such as allowing to change a clock's rate from userspace.
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
‘all_lists’ and ‘orphan_list’ is accessed only when DEBUG_FS is defined.
Thus, make their compilation conditional to fix the below warnings introduced
by commit 27b8d5f723 ("clk: flatten clk tree in debugfs"):
drivers/clk/clk.c:40:27: warning: ‘all_lists’ defined but not used [-Wunused-variable]
drivers/clk/clk.c:46:27: warning: ‘orphan_list’ defined but not used [-Wunused-variable]
Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This patch flattens the clk tree in CCF debugfs. Instead of representing the
clocks and their hierarchy as a directory structure under
/sys/kernel/debug/clk, each clock gets a single directory directly under
/sys/kernel/debug/clk. The orphans directory is replaced by a file called
clk_orphan_summary.
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Commit 99cbd064b0 ("clk: qcom: Support display RCG clocks") adds
a use of the __clk_round_rate in a clock provided that can be built
as a loadable module.
This exports the symbol to avoid the build error from compiling
the qcom clock as a module.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This simplifies error paths in drivers that use optional clocks
by allowing the NULL or error pointer to be passed
unconditionally.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The same if-else statement exists four times to recalculate the
rate of a clock. Consolidate this logic into a single function to
save some lines.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
We dereference clk->ops during clock registration so this check
for NULL ops can't possibly ever be true.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Now that clk_unregister() frees the struct clk we're
unregistering we'll free memory twice: first we'll call kfree()
in __clk_release() with an address kmalloc doesn't know about and
second we'll call kfree() in the devres layer. Remove the
allocation of struct clk in devm_clk_register() and let
clk_release() handle it. This fixes slab errors like:
=============================================================================
BUG kmalloc-128 (Not tainted): Invalid object pointer 0xed08e8d0
-----------------------------------------------------------------------------
Disabling lock debugging due to kernel taint
INFO: Slab 0xeec503f8 objects=25 used=15 fp=0xed08ea00 flags=0x4081
CPU: 2 PID: 73 Comm: rmmod Tainted: G B 3.14.0-11032-g526e9c764381 #34
[<c0014be0>] (unwind_backtrace) from [<c0012240>] (show_stack+0x10/0x14)
[<c0012240>] (show_stack) from [<c04b74dc>] (dump_stack+0x70/0xbc)
[<c04b74dc>] (dump_stack) from [<c00f6778>] (slab_err+0x74/0x84)
[<c00f6778>] (slab_err) from [<c04b6278>] (free_debug_processing+0x2cc/0x31c)
[<c04b6278>] (free_debug_processing) from [<c04b6300>] (__slab_free+0x38/0x41c)
[<c04b6300>] (__slab_free) from [<c03931bc>] (clk_unregister+0xd4/0x140)
[<c03931bc>] (clk_unregister) from [<c02fb774>] (release_nodes+0x164/0x1d8)
[<c02fb774>] (release_nodes) from [<c02f8698>] (__device_release_driver+0x60/0xb0)
[<c02f8698>] (__device_release_driver) from [<c02f9080>] (driver_detach+0xb4/0xb8)
[<c02f9080>] (driver_detach) from [<c02f8480>] (bus_remove_driver+0x5c/0xc4)
[<c02f8480>] (bus_remove_driver) from [<c008c9b8>] (SyS_delete_module+0x148/0x1d8)
[<c008c9b8>] (SyS_delete_module) from [<c000ef80>] (ret_fast_syscall+0x0/0x48)
FIX kmalloc-128: Object at 0xed08e8d0 not freed
Fixes: fcb0ee6a3d (clk: Implement clk_unregister)
Cc: Jiada Wang <jiada_wang@mentor.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@vger.kernel.org
This restores the default clocks registration order as parsed from
devicetree, i.e. as before commit 1771b10d60
"clk: respect the clock dependencies in of_clk_init", for when there
is no explicit parent clock dependencies between clock providers
specified in the device tree.
It prevents regressions (boot failure, division by 0 errors) on
imx and exynos platforms.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Add a new clk_ops->debug_init method to allow a clock hardware
driver to populate the clock's debugfs directory with entries
beyond those common for every clock.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
If a rate change failed it's the opportunity of the caller to handle
this. Do not spam the log with a message.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Until now the clock providers were initialized in the order found in
the device tree. This led to have the dependencies between the clocks
not respected: children clocks could be initialized before their
parent clocks.
Instead of forcing each platform to manage its own initialization order,
this patch adds this work inside the framework itself.
Using the data of the device tree the of_clk_init function now delayed
the initialization of a clock provider if its parent provider was not
ready yet.
The strict dependency check (all parents of a given clk must be
initialized) was added by Boris BREZILLON
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Ensure clk->kref is dereferenced only when clk is not NULL.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
At probe time, a clock device may not be ready when some other device
wants to use it.
This patch lets the functions clk_get/devm_clk_get return a probe defer
when the clock is defined in the DT but not yet available.
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Both the pr_err and the additional kerneldoc aim to help when debugging
errors thrown from within a clock rate-change notifier callback.
Reported-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Add a property called clock-indices to allow clock-output-names
to be used where the index used to lookup a clock is not a 1:1
mapping to the array position in the clock-output-names
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Contradicting to documenation, the notifier callbacks do receive
the original clock rate in struct clk_notifier_data.old_rate and the new
frequency struct clk_notifier_data.new_rate, independent of the
notification reason.
This behavior also seems to make more sense, since callbacks can use the
same code to deterimine whether clocks are scaled up or down. Something
which would not even possible in the post-rate-change case if the
behavior was as documented.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Allow drivers to be compiled as modules by exporting more clock
provider functions.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
ti_dt_clk_init_provider() can now be used to initialize the contents of
a single clock IP block. This parses all the clocks under the IP block
and calls the corresponding init function for them.
This patch also introduces a helper function for the TI clock drivers
to get register info from DT and append the master IP info to this.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Some of Qualcomm's clocks can change their parent and rate at the
same time with a single register write. Add support for this
hardware to the common clock framework by adding a new
set_rate_and_parent() op. When the clock framework determines
that both the parent and the rate are going to change during
clk_set_rate() it will call the .set_rate_and_parent() op if
available and fall back to calling .set_parent() followed by
.set_rate() otherwise.
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Populate ${DEBUGS_MOUNT_POINT}/clk if CONFIG_DEBUG_FS is set. This
eliminates the extra (annoying) step of enabling the config option
manually.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The clock accuracy is expressed in ppb (parts per billion) and represents
the possible clock drift.
Say you have a clock (e.g. an oscillator) which provides a fixed clock of
20MHz with an accuracy of +- 20Hz. This accuracy expressed in ppb is
20Hz/20MHz = 1000 ppb (or 1 ppm).
Clock users may need the clock accuracy information in order to choose
the best clock (the one with the best accuracy) across several available
clocks.
This patch adds clk accuracy retrieval support for common clk framework by
means of a new function called clk_get_accuracy.
This function returns the given clock accuracy expressed in ppb.
In order to get the clock accuracy, this implementation adds one callback
called recalc_accuracy to the clk_ops structure.
This callback is given the parent clock accuracy (if the clock is not a
root clock) and should recalculate the given clock accuracy.
This callback is optional and may be implemented if the clock is not
a perfect clock (accuracy != 0 ppb).
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
clk_unregister() is currently not implemented and it is required when
a clock provider module needs to be unloaded.
Normally the clock supplier module is prevented to be unloaded by
taking reference on the module in clk_get().
For cases when the clock supplier module deinitializes despite the
consumers of its clocks holding a reference on the module, e.g. when
the driver is unbound through "unbind" sysfs attribute, there are
empty clock ops added. These ops are assigned temporarily to struct
clk and used until all consumers release the clock, to avoid invoking
callbacks from the module which just got removed.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
This patch adds common __clk_get(), __clk_put() clkdev helpers that
replace their platform specific counterparts when the common clock
API is used.
The owner module pointer field is added to struct clk so a reference
to the clock supplier module can be taken by the clock consumers.
The owner module is assigned while the clock is being registered,
in functions _clk_register() and __clk_register().
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add helper functions for the of_clk_providers list locking and
an unlocked variant of of_clk_get_from_provider().
These functions are intended to be used in the clkdev to avoid
race condition in the device tree based clock look up in clk_get().
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
[Maybe the third time will be the charm. -Alex]
If CONFIG_COMMON_CLK_DEBUG is defined, clk_debug_create_one() is
called to populate a debugfs directory with a few entries that are
common for all clock types.
If an error happens after creating the first one debugfs_remove() is
called on the clock's directory. The problem with this is that no
cleanup is done on the debugfs files already created in that
directory, so the directory never actually gets removed. This
problem is silently ignored.
Fix this by calling debugfs_remove_recursive() instead. Reset the
clk->dentry field to null afterward, to ensure it can't be mistaken
as a valid pointer.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This function is supposed to iterate over all parents of given child
clock to find the index of given parent clock in its parent list,
using parent cache if possible and falling back to string compare
otherwise. However currently the logic falls back to string compare in
every iteration in which clock cache entry does not match given parent,
due to wrong check conditions.
This patch corrects the logic to continue the loop if parent cache entry
is present and does not match requested parent clock. In addition,
redundant checks for parent cache array presence are removed, because it
is always allocated in the beginning of the function.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Instead of calculating sizes of arrays manually, kcalloc() can be used
to allocate arrays of elements with defined size. This is just a cleanup
patch without any functional changes.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
There are at least two different error cases that can happen in
clk_fetch_parent_index() function:
- allocation failure,
- parent clock lookup failure,
however it returns only an u8, which is supposed to contain parent clock
index.
This patch modified the function to return full int instead allowing
positive clock indices and negative error codes to be returned. All
users of this function are adjusted as well to handle the return value
correctly.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
In __clk_init(), after a clock is mostly initialized, a scan is done
of the orphan clocks to see if the clock being registered is the
parent of any of them.
This code assumes that any clock that provides a get_parent method
actually has at least one parent, and that's not a valid assumption.
As a result, an orphan clock with no parent can return *something*
as the parent index, and that value is blindly used to dereference
the orphan's parent_names[] array (which will be ZERO_SIZE_PTR or
NULL).
Fix this by ensuring get_parent is only called for orphans with at
least one parent.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The __clk_get_flags() symbol is exported immediately following the
clk_unprepare_unused_subtree() function. This is unusual, since a symbol
export typically follows body of the function that it exports.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Commit 71472c0 (clk: add support for clock reparent on set_rate) added a
dereference of the new_parent pointer in clk_reparent(), but as detected
by smatch clk_reparent() later checks whether new_parent is NULL.
The dereference was in order to clear the new parent's new_child pointer
to avoid duplicate POST_RATE_CHANGE notifications, so clearly isn't
necessary if the new parent is NULL, so move it inside the "if
(new_parent)" block.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Currently of_clk_init() finds a matching device node while holding
the device tree spinlock. When a matching device node is found, the
lock is dropped and then re-acquired in order to get a reference
to the matching device id structure.
Acquiring the spinlock twice is unnecessary (and it opens a
vulnerable window that could conceivably lead to errors).
There already exists an interface for both finding and taking a
reference to a device id under lock, so use it.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Christian Daudt <csd@broadcom.com>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
At some point changes to clk_set_rate and clk_set_parent introduced a
bug whereby NULL struct clk pointers were treated as an error. This is
in violation of the API in include/linux/clk.h. Reintroduce graceful
handling of NULL clk's by bailing from clk_set_rate and clk_set_parent
with return codes of zero.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Implement clk-mux remuxing if the CLK_SET_RATE_NO_REPARENT flag isn't
set. This implements determine_rate for clk-mux to propagate to each
parent and to choose the best one (like clk-divider this chooses the
parent which provides the fastest rate <= the requested rate).
The determine_rate op is implemented as a core helper function so that
it can be easily used by more complex clocks which incorporate muxes.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Add core support to allow clock implementations to select the best
parent clock when rounding a rate, e.g. the one which can provide the
closest clock rate to that requested. This is by way of adding a new
clock op, determine_rate(), which is like round_rate() but has an extra
parameter to allow the clock implementation to optionally select a
different parent clock. The core then takes care of reparenting the
clock when setting the rate.
The parent change takes place with the help of some new private data
members. struct clk::new_parent specifies a clock's new parent (NULL
indicates no change), and struct clk::new_child specifies a clock's new
child (whose new_parent member points back to it). The purpose of these
are to allow correct walking of the future tree for notifications prior
to actually reparenting any clocks, specifically to skip child clocks
who are being reparented to another clock (they will be notified via the
new parent), and to include any new child clock. These pointers are set
by clk_calc_subtree(), and the new_child pointer gets cleared when a
child is actually reparented to avoid duplicate POST_RATE_CHANGE
notifications.
Each place where round_rate() is called, determine_rate() is checked
first and called in preference. This restructures a few of the call
sites to simplify the logic into if/else blocks.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Move some parent related functions up in clk.c so they can be used by
the modifications in the following patch which enables clock reparenting
during set_rate. No other changes are made so this patch makes no
functional difference in isolation. This is separate from the following
patch primarily to ease readability of that patch.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Abstract access to the clock parent cache by defining
clk_get_parent_by_index(clk, index). This allows access to parent
clocks from clock drivers.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
across several different platforms and architectures, fixes to existing
drivers, a MAINTAINERS file fix and improvements to the basic clock
types that allow them to be of use to more platforms than before. Only a
few fixes to the core framework are included with most all of the
changes landing in the various clock drivers themselves.
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Merge tag 'clk-for-linus-3.11' of git://git.linaro.org/people/mturquette/linux
Pull clock framework updates from Mike Turquette:
"The common clock framework changes for 3.11 include new clock drivers
across several different platforms and architectures, fixes to
existing drivers, a MAINTAINERS file fix and improvements to the basic
clock types that allow them to be of use to more platforms than before.
Only a few fixes to the core framework are included with most all of
the changes landing in the various clock drivers themselves."
* tag 'clk-for-linus-3.11' of git://git.linaro.org/people/mturquette/linux: (55 commits)
clk: tegra: fix ifdef for tegra_periph_reset_assert inline
clk: tegra: provide tegra_periph_reset_assert alternative
clk: exynos4: Fix clock aliases for cpufreq related clocks
clk: samsung: Add MUX_FA macro to pass flag and alias
clk: add support for Rockchip gate clocks
clk: vexpress: Make the clock drivers directly available for arm64
clk: vexpress: Use full node name to identify individual clocks
clk: tegra: T114: add DFLL DVCO reset control
clk: tegra: T114: add DFLL source clocks
clk: tegra: T114: add FCPU clock shaper programming, needed by the DFLL
clk: gate: add CLK_GATE_HIWORD_MASK
clk: divider: add CLK_DIVIDER_HIWORD_MASK flag
clk: mux: add CLK_MUX_HIWORD_MASK
clk: Always notify whole subtree when reparenting
MAINTAINERS: make drivers/clk entry match subdirs
clk: honor CLK_GET_RATE_NOCACHE in clk_set_rate
clk: use clk_get_rate() for debugfs
clk: tegra: Use override bits when needed
clk: tegra: override bits for Tegra30 PLLM
clk: tegra: override bits for Tegra114 PLLM
...
A clock's notifier count only reflects notifiers which are registered
directly for that clock. A reparent operation though affects the whole
subtree because of a potential rate change.
When issuing the pre rate change notifications only the notifier count
for the clock to be changed is considered and notifiers for subclocks
may never be called. Resulting in clocks in the subtree which have
registered notifiers, may receive a POST_- or ABORT_RATE_CHANGE
notification, without a PRE_RATE_CHANGE_NOTIFICATION.
Therefore always traverse the whole subtree when issueing pre rate
change notifications during a reparent operation.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
clk_set_rate() uses clk->rate directly. This causes problems if the clock
is marked as CLK_GET_RATE_NOCACHE. Hence call clk_get_rate() to get the
current rate.
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
debugfs uses the rate field directly. However this ignores the
CLK_GET_RATE_NOCACHE flag. Call clk_get_rate() instead.
Tested-by: Mark Zhang <markz@nvidia.com>
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
With deferred probing, late_initcall() is too soon to declare a clock as
unused. Wait for deferred probing to finish before declaring a clock as
unused. Since deferred probing is done in late_initcall(), do the unused
check to late_initcall_sync.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Without this patch, the following race condition is possible.
* clk-A has two parents - clk-X and clk-Y.
* All three are disabled and clk-X is current parent.
* Thread A: clk_set_parent(clk-A, clk-Y).
* Thread A: <snip execution flow>
* Thread A: Grabs enable lock.
* Thread A: Sees enable count of clk-A is 0, so doesn't enable clk-Y.
* Thread A: Updates clk-A SW parent to clk-Y
* Thread A: Releases enable lock.
* Thread B: clk_enable(clk-A).
* Thread B: clk_enable() enables clk-Y, then enabled clk-A and returns.
clk-A is now enabled in software, but not clocking in hardware since the
hardware parent is still clk-X.
The only way to avoid race conditions between clk_set_parent() and
clk_enable/disable() is to ensure that clk_enable/disable() calls don't
require changes to hardware enable state between changes to software clock
topology and hardware clock topology.
The options to achieve the above are:
1. Grab the enable lock before changing software/hardware topology and
release it afterwards.
2. Keep the clock enabled for the duration of software/hardware topology
change so that any additional enable/disable calls don't try to change
the hardware state. Once the topology change is complete, the clock can
be put back in its original enable state.
Option (1) is not an acceptable solution since the set_parent() ops might
need to sleep.
Therefore, this patch implements option (2).
This patch doesn't violate any API semantics. clk_disable() doesn't
guarantee that the clock is actually disabled. So, no clients of a clock
can assume that a clock is disabled after their last call to clk_disable().
So, enabling the clock during a parent change is not a violation of any API
semantics.
This also has the nice side effect of simplifying the error handling code.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up whitespace issue]
This is primarily useful when there's a driver that doesn't claim clocks
properly, but the bootloader leaves them on. It's not expected to be used
in normal cases, but for bringup and debug it's very useful to have the
option to not gate unclaimed clocks that are still on.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up trivial merge issue]
The common clock api provides some helpers for clk-providers but does
not export these helpers. This hinders clk-providers to be built as modules.
This patch adds __clk_get_flags() to the list of exported symbols.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Notifiers may return NOTIFY_(OK|DONE|STOP|BAD). The CCF uses an
inconsistent mix of checking against NOTIFY_STOP or NOTIFY_BAD.
This inconsistency leaves errors undetected in some cases:
clk_set_parent() calls __clk_speculate_rates(), which stops when it
hits a NOTIFIER_BAD (STOP is ignored), and passes this value back to the
caller.
clk_set_parent() compares this return value against NOTIFY_STOP only,
ignoring NOTIFY_BAD returns.
Use NOTIFY_STOP_MASK to detect a negative notifier return value and
document all four return value options.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Updating the clock tree topology must be protected with the spinlock
when doing clk_set_parent, otherwise we can not handle the migration
of the enable_count in a safe manner.
While issuing the .set_parent callback to make the clk-hw perform the
switch to the new parent, we can not hold the spinlock since it is must
be allowed to be slow path. This complicates error handling, but is still
possible to achieve.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Fixup the broken feature of allowing reparent of a clk to the
orhpan list and vice verse. When operating on a single-parent
clk, the .set_parent callback for the clk hw is optional to
implement, but for a multi-parent clk it is mandatory.
Moreover improve the errorhandling by verifying the prerequisites
before triggering clk notifiers. This will prevent unnecessary
rollback with ABORT_RATE_CHANGE.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Split __clk_reparent into three pieces, one for doing the actual
reparent for updating the clock tree topology, one for the
COMMON_CLK_DEBUG code and one for doing the rate recalculation.
This patch also makes it possible to hold the spinlock over the
update of the clock tree topology, which could not be done before
when both debugfs updates and clock rate updates was done within
the same function.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Reentrancy into the clock framework is necessary for clock operations
that result in nested calls to the clk api. A common example is a clock
that is prepared via an i2c transaction, such as a clock inside of a
discrete audio chip or a power management IC. The i2c subsystem itself
will use the clk api resulting in a deadlock:
clk_prepare(audio_clk)
i2c_transfer(..)
clk_prepare(i2c_controller_clk)
The ability to reenter the clock framework prevents this deadlock.
Other use cases exist such as allowing .set_rate callbacks to call
clk_set_parent to achieve the best rate, or to save power in certain
configurations. Yet another example is performing pinctrl operations
from a clk_ops callback. Calls into the pinctrl subsystem may call
clk_{un}prepare on an unrelated clock. Allowing for nested calls to
reenter the clock framework enables both of these use cases.
Reentrancy is implemented by two global pointers that track the owner
currently holding a global lock. One pointer tracks the owner during
sleepable, mutex-protected operations and the other one tracks the owner
during non-interruptible, spinlock-protected operations.
When the clk framework is entered we try to hold the global lock. If it
is held we compare the current task against the current owner; a match
implies a nested call and we reenter. If the values do not match then
we block on the lock until it is released.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Create locking helpers for the global mutex and global spinlock. The
definitions of these helpers will be expanded upon in the next patch
which introduces reentrancy into the locking scheme.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Return type of function clk_propagate_rate_change is a pointer.
But 0 was being returned. Change it to NULL.
Silences the following warning:
drivers/clk/clk.c:977:24: warning: Using plain integer as NULL pointer
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Pankaj Jangra <jangra.pankaj9@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
An unprepare_unused callback is introduced due to the same reasons to
why the disable_unused callback was added.
During the clk_disable_unused sequence, those clk_hw that needs specific
treatment with regards to being unprepared, shall implement the
unprepare_unused callback.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The unused ungated fast clocks are already being disabled from
clk_disable_unused at late init. This patch extend this sequence
to the slow unused prepared clocks to be unprepared.
Unless the optional .is_prepared callback is implemented by a
clk_hw the clk_disable_unused sequence will not unprepare any
unused clocks, since it will fall back to use the software
prepare counter.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed hlist accessors per b67bfe0d]
To reflect whether a clk_hw is prepared the clk_hw may implement
the optional is_prepared callback. If not implemented we fall back
to use the software prepare counter.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
I'm not sure why, but the hlist for each entry iterators were conceived
list_for_each_entry(pos, head, member)
The hlist ones were greedy and wanted an extra parameter:
hlist_for_each_entry(tpos, pos, head, member)
Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.
Besides the semantic patch, there was some manual work required:
- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.
The semantic patch which is mostly the work of Peter Senna Tschudin is here:
@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
type T;
expression a,c,d,e;
identifier b;
statement S;
@@
-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>
[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Modify of_clk_init function so that it will determine which
driver to initialize based on device tree instead of each driver
registering to it.
Based on a similar patch for drivers/irqchip by Thomas Petazzoni and
drivers/clocksource by Stephen Warren.
Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: Tony Prisk <linux@prisktech.co.nz>
Tested-by: Pawel Moll <pawel.moll@arm.com>
Tested-by: Rob Herring <rob.herring@calxeda.com>
Tested-by: Josh Cartwright <josh.cartwright@ni.com>
Reviewed-by: Josh Cartwright <josh.cartwright@ni.com>
Acked-by: Maxime Ripard <maxime.ripard@anandra.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: merge conflict from missing CLKSRC_OF_TABLES()]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
On non-out case 'return ret;' is equivalent to 'return 0;' as the ret
variable is initialized at 0 and never changed.
Signed-off-by: Nestor Ovroy <novroy@riseup.net>
Clock information is dumped in JSON format which is easy
for machines to parse.
Each clock is represented as an object which has same name as
clock and following properties
- enable_count
- prepare_count
- rate
Output is verified using online JSON editor.
Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This fixes the following error when building for arm-imx:
> ERROR: "__clk_get_name" [drivers/staging/imx-drm/ipu-v3/imx-ipu-v3.ko] undefined!
> make[1]: *** [__modpost] Error 1
> make: *** [modules] Error 2
There are valid usecases to get the name of a clock, be it for debugging
purposes or to register a children of a clock like done in this IPU driver.
Therefore exporting __clk_get_name() and make it available for others makes
sense.
Reported-by: Peter Robinson <pbrobinson@gmail.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
CC: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removal of inline made redundant by 65800b2]
The helper functions that access the opaque struct clk should
not be marked inline since they are contained in clk.c, but expected
to be used by other compilation units. This causes compile errors
under gcc-4.7
In file included from arch/arm/mach-omap2/clockdomain.c:25:0:
arch/arm/mach-omap2/clockdomain.c: In function ‘clkdm_clk_disable’:
include/linux/clk-provider.h:338:12: error: inlining failed in call to always_inline ‘__clk_get_enable_count’: function body not available
arch/arm/mach-omap2/clockdomain.c:1001:28: error: called from here
make[1]: *** [arch/arm/mach-omap2/clockdomain.o] Error 1
make: *** [arch/arm/mach-omap2] Error 2
Signed-off-by: Russ Dill <Russ.Dill@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removed fixes made redundant by commit 93532c8a]
[mturquette@linaro.org: improved $SUBJECT]
Some gate clocks have special needs which must be handled during the
disable-unused clocks sequence. These needs might be driven by software
due to the fact that we're disabling a clock outside of the normal
clk_disable path and a clk's enable_count will not be accurate. On the
other hand a specific hardware programming sequence might need to be
followed for this corner case.
This change is needed for the upcoming OMAP port to the common clock
framework. Specifically, it is undesirable to treat the disable-unused
path identically to the normal clk_disable path since other software
layers are involved. In this case OMAP's clockdomain code throws WARNs
and bails early due to the clock's enable_count being set to zero. A
custom callback mitigates this problem nicely.
Cc: Paul Walmsley <paul@pwsan.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
When a clock, C is initialised any orphan clocks listing C as
a possible parent are reparented to it regardless of the
parent requested by the orphan's get_parent() operation.
This means that multiplexers registered before their parents
are reparented to the first parent subsequently declared,
regardless of the selection made by the hardware registers.
For example:
static const char *sel[] = { "srcA", "srcB", "dummy", "srcC" };
child = clk_register_mux(NULL, "child", sel, ARRAY_SIZE(sel), ...);
clk_register_fixed(NULL, "dummy", ...);
clk_register_fixed(NULL, "srcA", ...);
clk_register_fixed(NULL, "srcB", ...);
clk_register_fixed(NULL, "srcC", ...);
Causes child's parent to always be "dummy".
To fix this, when an orphanned clock has a get_parent() operation,
only reparent to the clock indicated by get_parent().
Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: improve $SUBJECT]
Some clock drivers can be simplified if devres takes care of
unregistering any registered clocks along error paths. Introduce
devm_clk_register() so that clock drivers get unregistration for
free along with simplified error paths.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Some of the helper functions return negative error codes if
passed a NULL clock. This can lead to confusing behavior when the
expected return value is unsigned. Fix up these accessors so that
they return unsigned values (or bool in the case of is_enabled).
This way we can't interpret NULL clocks as having valid and
interesting values.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
For those SoCs that have hundreds of clock outputs, their clock
DT bindings could reasonably define #clock-cells as 1 and require
the client device specify the index of the clock it consumes in the
cell of its "clocks" phandle.
Add a generic of_clk_src_onecell_get() function for this purpose.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
By using CLK_GET_RATE_NOCACHE flag, we tell the clk_get_rate API to
issue the hw for an updated clock rate. This can be used for a clock
which rate may be updated without a client necessary modifying it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
clk_get() returns -ENOENT on error and some careless caller might
dereference it without error checking:
In mxc_rnga_remove():
struct clk *clk = clk_get(&pdev->dev, "rng");
// ...
clk_disable(clk);
Since it's insane to audit the lots of existing and future clk users,
let's add a check in the callee to avoid kernel panic and warn about
any buggy user.
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
Cc: viresh kumar <viresh.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant
Likely, this patch adds support to clk_get to allow drivers to retrieve
clock data from the device tree.
Platforms scan for clocks in DT with of_clk_init and a match table, and
the register a provider through of_clk_add_provider. The provider's
clk_src_get function will be called when a device references the
provider's OF node for a clock reference.
v6 (Rob Herring):
- Return error values instead of NULL to match clock framework
expectations
v5 (Rob Herring):
- Move from drivers/of into common clock subsystem
- Squashed "dt/clock: add a simple provider get function" and
"dt/clock: add function to get parent clock name"
- Rebase to 3.4-rc1
- Drop CONFIG_OF_CLOCK and just use CONFIG_OF
- Add missing EXPORT_SYMBOL to various functions
- s/clock-output-name/clock-output-names/
- Define that fixed-clock binding is a single output
v4 (Rob Herring):
- Rework for common clk subsystem
- Add of_clk_get_parent_name function
v3: - Clarified documentation
v2: - fixed errant ';' causing compile error
- Editorial fixes from Shawn Guo
- merged in adding lookup to clkdev
- changed property names to match established convention. After
working with the binding a bit it really made more sense to follow the
lead of 'reg', 'gpios' and 'interrupts' by making the input simply
'clocks' & 'clock-names' instead of 'clock-input-*', and to only use
clock-output* for the producer nodes. (Sorry Shawn, this will mean
you need to change some code, but it should be trivial)
- Add ability to inherit clocks from parent nodes by using an empty
'clock-ranges' property. Useful for busses. I could use some feedback
on the new property name, 'clock-ranges' doesn't feel right to me.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
caching parent clocks makes sense only when a clock has more
than one parent (mux clocks).
Avoid doing this for every other clock.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
[mturquette@linaro.org: removed extra parentheses]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The below commit introduced a bug in __clk_set_parent()
which could cause it to *skip* the parent validation
which makes sure the parent passed to the api is a valid
one.
commit 7975059db5
Author: Rajendra Nayak <rnayak@ti.com>
Date: Wed Jun 6 14:41:31 2012 +0530
clk: Allow late cache allocation for clk->parents
This was identified by the following compiler warning..
drivers/clk/clk.c: In function '__clk_set_parent':
drivers/clk/clk.c:1083:5: warning: 'i' may be used uninitialized in this function [-Wuninitialized]
.. as reported by Marc Kleine-Budde.
There were various options discussed on how to fix this, one
being initing 'i' to clk->num_parents, but the below approach
was found to be more appropriate as it also makes the 'parent
validation' code simpler to read.
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org
clk_change_rate() is accessing parent's rate without checking
if the parent exists at all. In case of root clocks this will
cause NULL pointer dereference.
This patch follows what clk_calc_new_rates() does in such
situation.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org
Parent clocks for muxes are cached in clk->parents to
avoid frequent lookups, however the cache allocation happens
only during clock registeration and later clk_set_parent()
assumes a cache space available and allocated.
This is not entirely true for platforms which do early clock
registerations wherein the cache allocation using kzalloc
could fail during clock registeration.
Allow cache allocation to happen later as part of clk_set_parent()
to help such cases and avoid crashes assuming a cache being
available.
While here also replace existing kmalloc() with kzalloc()
in the file.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org
The clk_set_rate() code shouldn't check the clock's enable count when
validating CLK_SET_RATE_GATE flag since the enable count could change after
the validation. Similar to clk_set_parent(), it should instead check the
prepare count. The prepare count should go to zero only when the end user
expects the clock to not be enabled in the future. Since the code already
grabs the prepare count before validation, it's not possible for prepare
count to change after validation and by association not possible for a well
behaving end user to enable the clock while the set rate is in progress.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Reviewed-by: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
While there's no actual implementation behind it having the call to use
in drivers makes them feel neater from a driver author point of view. An
actual implementation can wait for someone who needs to use the function
in a real system.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[mturquette@linaro.org: void return type instead of int -EINVAL]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Exposing this option generates confusion and incorrect behavior for
single-image builds across platforms. Enable this behavior permanently.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Patch 'clk: always pass parent_rate into .round_rate' made a subtle
change to the semantics of .round_rate. It is now expected for the
parent's rate to always be passed in, simplifying the implemenation of
various .round_rate callback definitions.
However the patch also introduced a bug in clk_calc_new_rates whereby a
clock without the CLK_SET_RATE_PARENT flag set could still propagate a
rate change up to a parent clock if the the .round_rate callback
modified the &best_parent_rate value in any way.
This patch fixes the issue at the framework level (in
clk_calc_new_rates) by specifically handling the case where the
CLK_SET_RATE_PARENT flag is not set.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
This is well documented but isn't implemented. clk_set_rate() must check if
flags have CLK_SET_RATE_GATE bit set and is enabled too.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Create a struct clk_init_data to hold all data that needs to be passed from
the platfrom specific driver to the common clock framework during clock
registration. Add a pointer to this struct inside clk_hw.
This has several advantages:
* Completely hides struct clk from many clock platform drivers and static
clock initialization code that don't care for static initialization of
the struct clks.
* For platforms that want to do complete static initialization, it removed
the need to directly mess with the struct clk's fields while still
allowing to statically allocate struct clk. This keeps the code more
future proof even if they include clk-private.h.
* Simplifies the generic clk_register() function and allows adding optional
fields in the future without modifying the function signature.
* Simplifies the static initialization of clocks on all platforms by
removing the need for forward delcarations or convoluted macros.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
[mturquette@linaro.org: kept DEFINE_CLK_* macros and __clk_init]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Deepak Saxena <dsaxena@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
if (!clk->ops->round_rate && (clk->flags & CLK_SET_RATE_PARENT)) is true, then
we don't need to set clk->new_rate here, as we will call clk_calc_subtree()
afterwards and it also sets clk->new_rate.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Need to propagate round_rate call for the clk that has no .round_rate
operation but with flag CLK_SET_RATE_PARENT set.
For example, clk_mux is a clk with no .round_rate operation. However,
it could likely be in a clk_set_rate propagation path, saying it has
parent clk who has .round_rate and .set_rate operations.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
For most of .set_rate implementation, parent_rate will be used, so just
like passing parent_rate into .recalc_rate, let's pass parent_rate into
.set_rate too.
It also updates the kernel doc for .set_rate ops.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The parent_rate will likely be used by most .round_rate implementation
no matter whether flag CLK_SET_RATE_PARENT is set or not, so let's
always pass parent_rate into .round_rate.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This patch cleans up clk_register and solves a few bugs by teaching
clk_register and __clk_init to return error codes (instead of just NULL)
to better align with the existing clk.h api.
Along with that change this patch also introduces a new behavior whereby
clk_register copies the parent_names array, thus allowing platforms to
declare their parent_names arrays as __initdata.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Drivers should be able to declare their arrays of parent names as const
so the APIs need to accept const arguments.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[mturquette@linaro.org: constified gate]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Most users of clk_get_rate() actually assume a non zero
return value as a valid rate returned. Returing -EINVAL
might confuse such users, so make it instead return zero
on error.
Besides the return value of clk_get_rate seems to be
'unsigned long'.
Signed-off-by: Rajendra nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Documentation/clk.txt has some handsome ASCII art outlining which
clk_ops are mandatory for a given clock, given the capability of the
hardware. Enforce those mandates with sanity checks in __clk_init.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
It is possible to call clk_set_rate on a clock with a NULL parent. One
such example is an adjustable-rate root clock. Ensure that
clk_calc_new_rates does not dereference parent without checking first
and also handle the corner cases gracefully.
Reported-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Some static inline dummy functions were left over from before the clock
core was consolidated from several C files down to one. Remove them.
Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Remove old and misleading documentation from the previous clk_set_rate
implementaion.
Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The common clock framework defines a common struct clk useful across
most platforms as well as an implementation of the clk api that drivers
can use safely for managing clocks.
The net result is consolidation of many different struct clk definitions
and platform-specific clock framework implementations.
This patch introduces the common struct clk, struct clk_ops and an
implementation of the well-known clock api in include/clk/clk.h.
Platforms may define their own hardware-specific clock structure and
their own clock operation callbacks, so long as it wraps an instance of
struct clk_hw.
See Documentation/clk.txt for more details.
This patch is based on the work of Jeremy Kerr, which in turn was based
on the work of Ben Herrenschmidt.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Mike Turquette <mturquette@ti.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Rob Herring <rob.herring <at> calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
Cc: Arnd Bergman <arnd.bergmann@linaro.org>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Richard Zhao <richard.zhao@linaro.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Deepak Saxena <dsaxena@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Sylwester Nawrocki