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path: root/drivers/clk/clk.c
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2013-09-09clk: only call get_parent if there is oneAlex Elder
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>
2013-09-03clk: Move symbol export to proper locationThierry Reding
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>
2013-08-30clk: fix new_parent dereference before null checkJames Hogan
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>
2013-08-27clk: get matching entry under lock in of_clk_init()Alex Elder
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>
2013-08-21clk: handle NULL struct clk gracefullyMike Turquette
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>
2013-08-19clk: clk-mux: implement remuxing on set_rateJames Hogan
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>
2013-08-19clk: add support for clock reparent on set_rateJames Hogan
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>
2013-08-19clk: move some parent related functions upwardsJames Hogan
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>
2013-08-19clk: abstract parent cacheJames Hogan
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>
2013-07-25clk: fix typosPeter Meerwald
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-07-03Merge tag 'clk-for-linus-3.11' of git://git.linaro.org/people/mturquette/linuxLinus Torvalds
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 ...
2013-06-15clk: Always notify whole subtree when reparentingSoren Brinkmann
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>
2013-06-11clk: honor CLK_GET_RATE_NOCACHE in clk_set_ratePeter De Schrijver
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>
2013-06-11clk: use clk_get_rate() for debugfsPeter De Schrijver
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>
2013-06-06clk: remove notifier from list before freeing itLai Jiangshan
The @cn is stay in @clk_notifier_list after it is freed, it cause memory corruption. Example, if @clk is registered(first), unregistered(first), registered(second), unregistered(second). The freed @cn will be used when @clk is registered(second), and the bug will be happened when @clk is unregistered(second): [ 517.040000] clk_notif_dbg clk_notif_dbg.1: clk_notifier_unregister() [ 517.040000] Unable to handle kernel paging request at virtual address 00df3008 [ 517.050000] pgd = ed858000 [ 517.050000] [00df3008] *pgd=00000000 [ 517.060000] Internal error: Oops: 5 [#1] PREEMPT SMP ARM [ 517.060000] Modules linked in: clk_notif_dbg(O-) [last unloaded: clk_notif_dbg] [ 517.060000] CPU: 1 PID: 499 Comm: modprobe Tainted: G O 3.10.0-rc3-00119-ga93cb29-dirty #85 [ 517.060000] task: ee1e0180 ti: ee3e6000 task.ti: ee3e6000 [ 517.060000] PC is at srcu_readers_seq_idx+0x48/0x84 [ 517.060000] LR is at srcu_readers_seq_idx+0x60/0x84 [ 517.060000] pc : [<c0052720>] lr : [<c0052738>] psr: 80070013 [ 517.060000] sp : ee3e7d48 ip : 00000000 fp : ee3e7d6c [ 517.060000] r10: 00000000 r9 : ee3e6000 r8 : 00000000 [ 517.060000] r7 : ed84fe4c r6 : c068ec90 r5 : c068e430 r4 : 00000000 [ 517.060000] r3 : 00df3000 r2 : 00000000 r1 : 00000002 r0 : 00000000 [ 517.060000] Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 517.060000] Control: 18c5387d Table: 2d85804a DAC: 00000015 [ 517.060000] Process modprobe (pid: 499, stack limit = 0xee3e6238) [ 517.060000] Stack: (0xee3e7d48 to 0xee3e8000) .... [ 517.060000] [<c0052720>] (srcu_readers_seq_idx+0x48/0x84) from [<c0052790>] (try_check_zero+0x34/0xfc) [ 517.060000] [<c0052790>] (try_check_zero+0x34/0xfc) from [<c00528b0>] (srcu_advance_batches+0x58/0x114) [ 517.060000] [<c00528b0>] (srcu_advance_batches+0x58/0x114) from [<c0052c30>] (__synchronize_srcu+0x114/0x1ac) [ 517.060000] [<c0052c30>] (__synchronize_srcu+0x114/0x1ac) from [<c0052d14>] (synchronize_srcu+0x2c/0x34) [ 517.060000] [<c0052d14>] (synchronize_srcu+0x2c/0x34) from [<c0053a08>] (srcu_notifier_chain_unregister+0x68/0x74) [ 517.060000] [<c0053a08>] (srcu_notifier_chain_unregister+0x68/0x74) from [<c0375a78>] (clk_notifier_unregister+0x7c/0xc0) [ 517.060000] [<c0375a78>] (clk_notifier_unregister+0x7c/0xc0) from [<bf008034>] (clk_notif_dbg_remove+0x34/0x9c [clk_notif_dbg]) [ 517.060000] [<bf008034>] (clk_notif_dbg_remove+0x34/0x9c [clk_notif_dbg]) from [<c02bb974>] (platform_drv_remove+0x24/0x28) [ 517.060000] [<c02bb974>] (platform_drv_remove+0x24/0x28) from [<c02b9bf8>] (__device_release_driver+0x8c/0xd4) [ 517.060000] [<c02b9bf8>] (__device_release_driver+0x8c/0xd4) from [<c02ba680>] (driver_detach+0x9c/0xc4) [ 517.060000] [<c02ba680>] (driver_detach+0x9c/0xc4) from [<c02b99c4>] (bus_remove_driver+0xcc/0xfc) [ 517.060000] [<c02b99c4>] (bus_remove_driver+0xcc/0xfc) from [<c02bace4>] (driver_unregister+0x54/0x78) [ 517.060000] [<c02bace4>] (driver_unregister+0x54/0x78) from [<c02bbb44>] (platform_driver_unregister+0x1c/0x20) [ 517.060000] [<c02bbb44>] (platform_driver_unregister+0x1c/0x20) from [<bf0081f8>] (clk_notif_dbg_driver_exit+0x14/0x1c [clk_notif_dbg]) [ 517.060000] [<bf0081f8>] (clk_notif_dbg_driver_exit+0x14/0x1c [clk_notif_dbg]) from [<c00835e4>] (SyS_delete_module+0x200/0x28c) [ 517.060000] [<c00835e4>] (SyS_delete_module+0x200/0x28c) from [<c000edc0>] (ret_fast_syscall+0x0/0x48) [ 517.060000] Code: e5973004 e7911102 e0833001 e2881002 (e7933101) Cc: stable@kernel.org Reported-by: Sören Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Tested-by: Sören Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Mike Turquette <mturquette@linaro.org> [mturquette@linaro.org: shortened $SUBJECT]
2013-05-29clk: Disable unused clocks after deferred probing is doneSaravana Kannan
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>
2013-05-28clk: Fix race condition between clk_set_parent and clk_enable()Saravana Kannan
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]
2013-04-27clk: add clk_ignore_unused option to keep boot clocks onOlof Johansson
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]
2013-04-15clk: export __clk_get_flags for modular clock providersSebastian Hesselbarth
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>
2013-04-10clk: Properly handle notifier return valuesSoren Brinkmann
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>
2013-04-08clk: Fixup locking issues for clk_set_parentUlf Hansson
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>
2013-04-08clk: Fixup errorhandling for clk_set_parentUlf Hansson
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>
2013-04-08clk: Restructure code for __clk_reparentUlf Hansson
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>
2013-04-02clk: allow reentrant calls into the clk frameworkMike Turquette
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>
2013-04-02clk: abstract locking out into helper functionsMike Turquette
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>
2013-03-22clk: Fix incorrect return type in clk.cSachin Kamat
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>
2013-03-19clk: Introduce optional unprepare_unused callbackUlf Hansson
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>
2013-03-19clk: Unprepare the unused prepared slow clocks at late initUlf Hansson
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]
2013-03-19clk: Introduce optional is_prepared callbackUlf Hansson
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>
2013-02-27hlist: drop the node parameter from iteratorsSasha Levin
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>
2013-01-24clk: add common of_clk_init() functionPrashant Gaikwad
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>
2013-01-21clk: Deduplicate exit code in clk_set_rateNestor Ovroy
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>
2013-01-11clk: JSON debugfs clock tree summaryPrashant Gaikwad
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>
2013-01-11clk: human-readable debugfs clock tree summaryPrashant Gaikwad
Adds debug file "clk_summary" in /sys/kernel/debug/clk dir. It helps to view all the clock registered in human-readable format. For example: clock enable_cnt prepare_cnt rate --------------------------------------------------------------------- i2s0_sync 0 0 24000000 spdif_in_sync 0 0 24000000 spdif_mux 0 0 24000000 spdif 0 0 24000000 spdif_doubler 0 0 48000000 spdif_div 0 0 48000000 spdif_2x 0 0 48000000 clk_32k 2 2 32768 blink_override 1 1 32768 blink 1 1 32768 clk_m 2 2 12000000 clk_out_3_mux 0 0 12000000 clk_out_3 0 0 12000000 pll_ref 3 3 12000000 pll_e_mux 0 0 12000000 pll_e 0 0 100000000 cml0 0 0 100000000 cml1 0 0 100000000 pciex 0 0 100000000 pll_d2 0 0 1000000 pll_d2_out0 0 0 500000 pll_d 0 0 1000000 pll_d_out0 0 0 500000 dsib_mux 0 0 500000 dsib 0 0 500000 dsia 0 0 500000 Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-01-11clk: export __clk_get_name for re-use in imx-ipu-v3 and othersNiels de Vos
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]
2013-01-11clk: Don't mark shared helper functions as inlineRuss Dill
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]
2012-12-10clk: introduce optional disable_unused callbackMike Turquette
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>
2012-11-26clk: clock multiplexers may register out of orderMartin Fuzzey
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]
2012-10-29clk: Add devm_clk_{register,unregister}()Stephen Boyd
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>
2012-10-29clk: Don't return negative numbers for unsigned values with !clkStephen Boyd
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>
2012-09-07clk: add of_clk_src_onecell_get() supportShawn Guo
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>
2012-09-06clk: Provide option for clk_get_rate to issue hw for new rateUlf Hansson
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>
2012-07-30clk: validate pointer in __clk_disable()Fengguang Wu
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>
2012-07-11clk: add DT clock binding supportGrant Likely
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>
2012-07-11clk: cache parent clocks only for muxesRajendra Nayak
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>
2012-07-03clk: fix parent validation in __clk_set_parent()Rajendra Nayak
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 7975059db572eb47f0fb272a62afeae272a4b209 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
2012-06-25clk: Check parent for NULL in clk_change_ratePawel Moll
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
2012-06-25clk: Allow late cache allocation for clk->parentsRajendra Nayak
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
2012-05-15clk: Fix CLK_SET_RATE_GATE flag validation in clk_set_rate().Saravana Kannan
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>
2012-05-15clk: Provide dummy clk_unregister()Mark Brown
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>