We don't need to fetch the parent index for clocks if they only
have one parent. Doing this also avoid an unnecessary allocation
for the parent cache.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

The commit 646cafc6 (clk: Change clk_ops->determine_rate to
return a clk_hw as the best parent) opens a possibility for
null pointer dereference, fix this.
Signed-off-by: NStanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

Commit 6314b679 (clk: Don't hold prepare_lock across debugfs
creation, 2014-09-04) forgot to update one place where we hold
the prepare_lock while creating debugfs directories. This means
we still have the chance of a deadlock that the commit was trying
to fix. Actually fix it by moving the debugfs creation outside
the prepare_lock.

Cc: <stable@vger.kernel.org> # 3.18
Reported-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Fixes: 6314b679 "clk: Don't hold prepare_lock across debugfs creation"
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removed lockdep_assert]

This is in preparation for clock providers to not have to deal with struct clk.
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

Instead of struct clk, as this should be only used by providers.
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

As it's only used internally, in drivers/clk/clk.c.
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

As __clk_release could call kfree on clk and then we wouldn't have a safe way
of getting the module that owns the clock.
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Fixes: fcb0ee6a ("clk: Implement clk_unregister")
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

It's the same to the next statement, "ret = clk->parent". I think compiler will
optimize it, it's just not looking well.
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

The current phase API doesn't look into the actual hardware to get the phase
value, but will rather get it from a variable only set by the set_phase
function.

This will cause issue when the client driver will never call the set_phase
function, where we can end up having a reported phase that will not match what
the hardware has been programmed to by the bootloader or what phase is
programmed out of reset.

Add a new get_phase function for the drivers to implement so that we can get
this value.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NHans de Goede <hdegoede@redhat.com>

A common operation for a clock signal generator is to shift the phase of
that signal. This patch introduces a new function to the clk.h API to
dynamically adjust the phase of a clock signal. Additionally this patch
introduces support for the new function in the common clock framework
via the .set_phase call back in struct clk_ops.
Signed-off-by: NMike Turquette <mturquette@linaro.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NHans de Goede <hdegoede@redhat.com>

Rob Clark reports a lockdep splat that involves the prepare_lock
chained with the mmap semaphore.

======================================================
[ INFO: possible circular locking dependency detected ]
3.17.0-rc1-00050-g07a489b #802 Tainted: G        W
-------------------------------------------------------
Xorg.bin/5413 is trying to acquire lock:
 (prepare_lock){+.+.+.}, at: [<c0781280>] clk_prepare_lock+0x88/0xfc

but task is already holding lock:
 (qcom_iommu_lock){+.+...}, at: [<c079f664>] qcom_iommu_unmap+0x1c/0x1f0

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (qcom_iommu_lock){+.+...}:
       [<c079f860>] qcom_iommu_map+0x28/0x450
       [<c079eb50>] iommu_map+0xc8/0x12c
       [<c056c1fc>] msm_iommu_map+0xb4/0x130
       [<c05697bc>] msm_gem_get_iova_locked+0x9c/0xe8
       [<c0569854>] msm_gem_get_iova+0x4c/0x64
       [<c0562208>] mdp4_kms_init+0x4c4/0x6c0
       [<c056881c>] msm_load+0x2ac/0x34c
       [<c0545724>] drm_dev_register+0xac/0x108
       [<c0547510>] drm_platform_init+0x50/0xf0
       [<c0578a60>] try_to_bring_up_master.part.3+0xc8/0x108
       [<c0578b48>] component_master_add_with_match+0xa8/0x104
       [<c0568294>] msm_pdev_probe+0x64/0x70
       [<c057e704>] platform_drv_probe+0x2c/0x60
       [<c057cff8>] driver_probe_device+0x108/0x234
       [<c057b65c>] bus_for_each_drv+0x64/0x98
       [<c057cec0>] device_attach+0x78/0x8c
       [<c057c590>] bus_probe_device+0x88/0xac
       [<c057c9b8>] deferred_probe_work_func+0x68/0x9c
       [<c0259db4>] process_one_work+0x1a0/0x40c
       [<c025a710>] worker_thread+0x44/0x4d8
       [<c025ec54>] kthread+0xd8/0xec
       [<c020e9a8>] ret_from_fork+0x14/0x2c

-> #3 (&dev->struct_mutex){+.+.+.}:
       [<c0541188>] drm_gem_mmap+0x38/0xd0
       [<c05695b8>] msm_gem_mmap+0xc/0x5c
       [<c02f0b6c>] mmap_region+0x35c/0x6c8
       [<c02f11ec>] do_mmap_pgoff+0x314/0x398
       [<c02de1e0>] vm_mmap_pgoff+0x84/0xb4
       [<c02ef83c>] SyS_mmap_pgoff+0x94/0xbc
       [<c020e8e0>] ret_fast_syscall+0x0/0x48

-> #2 (&mm->mmap_sem){++++++}:
       [<c0321138>] filldir64+0x68/0x180
       [<c0333fe0>] dcache_readdir+0x188/0x22c
       [<c0320ed0>] iterate_dir+0x9c/0x11c
       [<c03213b0>] SyS_getdents64+0x78/0xe8
       [<c020e8e0>] ret_fast_syscall+0x0/0x48

-> #1 (&sb->s_type->i_mutex_key#3){+.+.+.}:
       [<c03fc544>] __create_file+0x58/0x1dc
       [<c03fc70c>] debugfs_create_dir+0x1c/0x24
       [<c0781c7c>] clk_debug_create_subtree+0x20/0x170
       [<c0be2af8>] clk_debug_init+0xec/0x14c
       [<c0208c70>] do_one_initcall+0x8c/0x1c8
       [<c0b9cce4>] kernel_init_freeable+0x13c/0x1dc
       [<c0877bc4>] kernel_init+0x8/0xe8
       [<c020e9a8>] ret_from_fork+0x14/0x2c

-> #0 (prepare_lock){+.+.+.}:
       [<c087c408>] mutex_lock_nested+0x70/0x3e8
       [<c0781280>] clk_prepare_lock+0x88/0xfc
       [<c0782c50>] clk_prepare+0xc/0x24
       [<c079f474>] __enable_clocks.isra.4+0x18/0xa4
       [<c079f614>] __flush_iotlb_va+0xe0/0x114
       [<c079f6f4>] qcom_iommu_unmap+0xac/0x1f0
       [<c079ea3c>] iommu_unmap+0x9c/0xe8
       [<c056c2fc>] msm_iommu_unmap+0x64/0x84
       [<c0569da4>] msm_gem_free_object+0x11c/0x338
       [<c05413ec>] drm_gem_object_handle_unreference_unlocked+0xfc/0x130
       [<c0541604>] drm_gem_object_release_handle+0x50/0x68
       [<c0447a98>] idr_for_each+0xa8/0xdc
       [<c0541c10>] drm_gem_release+0x1c/0x28
       [<c0540b3c>] drm_release+0x370/0x428
       [<c031105c>] __fput+0x98/0x1e8
       [<c025d73c>] task_work_run+0xb0/0xfc
       [<c02477ec>] do_exit+0x2ec/0x948
       [<c0247ec0>] do_group_exit+0x4c/0xb8
       [<c025180c>] get_signal+0x28c/0x6ac
       [<c0211204>] do_signal+0xc4/0x3e4
       [<c02116cc>] do_work_pending+0xb4/0xc4
       [<c020e938>] work_pending+0xc/0x20

other info that might help us debug this:

Chain exists of:
  prepare_lock --> &dev->struct_mutex --> qcom_iommu_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(qcom_iommu_lock);
                               lock(&dev->struct_mutex);
                               lock(qcom_iommu_lock);
  lock(prepare_lock);

 *** DEADLOCK ***

3 locks held by Xorg.bin/5413:
 #0:  (drm_global_mutex){+.+.+.}, at: [<c0540800>] drm_release+0x34/0x428
 #1:  (&dev->struct_mutex){+.+.+.}, at: [<c05413bc>] drm_gem_object_handle_unreference_unlocked+0xcc/0x130
 #2:  (qcom_iommu_lock){+.+...}, at: [<c079f664>] qcom_iommu_unmap+0x1c/0x1f0

stack backtrace:
CPU: 1 PID: 5413 Comm: Xorg.bin Tainted: G        W      3.17.0-rc1-00050-g07a489b #802
[<c0216290>] (unwind_backtrace) from [<c0211d8c>] (show_stack+0x10/0x14)
[<c0211d8c>] (show_stack) from [<c087a078>] (dump_stack+0x98/0xb8)
[<c087a078>] (dump_stack) from [<c027f024>] (print_circular_bug+0x218/0x340)
[<c027f024>] (print_circular_bug) from [<c0283e08>] (__lock_acquire+0x1d24/0x20b8)
[<c0283e08>] (__lock_acquire) from [<c0284774>] (lock_acquire+0x9c/0xbc)
[<c0284774>] (lock_acquire) from [<c087c408>] (mutex_lock_nested+0x70/0x3e8)
[<c087c408>] (mutex_lock_nested) from [<c0781280>] (clk_prepare_lock+0x88/0xfc)
[<c0781280>] (clk_prepare_lock) from [<c0782c50>] (clk_prepare+0xc/0x24)
[<c0782c50>] (clk_prepare) from [<c079f474>] (__enable_clocks.isra.4+0x18/0xa4)
[<c079f474>] (__enable_clocks.isra.4) from [<c079f614>] (__flush_iotlb_va+0xe0/0x114)
[<c079f614>] (__flush_iotlb_va) from [<c079f6f4>] (qcom_iommu_unmap+0xac/0x1f0)
[<c079f6f4>] (qcom_iommu_unmap) from [<c079ea3c>] (iommu_unmap+0x9c/0xe8)
[<c079ea3c>] (iommu_unmap) from [<c056c2fc>] (msm_iommu_unmap+0x64/0x84)
[<c056c2fc>] (msm_iommu_unmap) from [<c0569da4>] (msm_gem_free_object+0x11c/0x338)
[<c0569da4>] (msm_gem_free_object) from [<c05413ec>] (drm_gem_object_handle_unreference_unlocked+0xfc/0x130)
[<c05413ec>] (drm_gem_object_handle_unreference_unlocked) from [<c0541604>] (drm_gem_object_release_handle+0x50/0x68)
[<c0541604>] (drm_gem_object_release_handle) from [<c0447a98>] (idr_for_each+0xa8/0xdc)
[<c0447a98>] (idr_for_each) from [<c0541c10>] (drm_gem_release+0x1c/0x28)
[<c0541c10>] (drm_gem_release) from [<c0540b3c>] (drm_release+0x370/0x428)
[<c0540b3c>] (drm_release) from [<c031105c>] (__fput+0x98/0x1e8)
[<c031105c>] (__fput) from [<c025d73c>] (task_work_run+0xb0/0xfc)
[<c025d73c>] (task_work_run) from [<c02477ec>] (do_exit+0x2ec/0x948)
[<c02477ec>] (do_exit) from [<c0247ec0>] (do_group_exit+0x4c/0xb8)
[<c0247ec0>] (do_group_exit) from [<c025180c>] (get_signal+0x28c/0x6ac)
[<c025180c>] (get_signal) from [<c0211204>] (do_signal+0xc4/0x3e4)
[<c0211204>] (do_signal) from [<c02116cc>] (do_work_pending+0xb4/0xc4)
[<c02116cc>] (do_work_pending) from [<c020e938>] (work_pending+0xc/0x20)

We can break this chain if we don't hold the prepare_lock while
creating debugfs directories. We only hold the prepare_lock right
now because we're traversing the clock tree recursively and we
don't want the hierarchy to change during the traversal.
Replacing this traversal with a simple linked list walk allows us
to only grab a list lock instead of the prepare_lock, thus
breaking the lock chain.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

In some cases, clocks can switch their parent with clk_set_rate, for
example clk_mux can do this in some cases. Current implementation of
clk_change_rate uses un-safe list iteration on the clock children, which
will cause wrong clocks to be parsed in case any of the clock children
change their parents during the change rate operation. Fixed by using
the safe list iterator instead.

The problem was detected due to some divide by zero errors generated
by clock init on dra7-evm board, see discussion under
http://article.gmane.org/gmane.linux.ports.arm.kernel/349180 for details.

Fixes: 71472c0c ("clk: add support for clock reparent on set_rate")
Signed-off-by: NTero Kristo <t-kristo@ti.com>
Reported-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

If the .debug_init op is provided, it will be called by
clk_debug_create_one(). If debug_init() returns an error code,
clk_debug_create_one() will return -ENOMEM, regardless of the
value returned from debug_init(). Tweak the code to return
the actual value returned by debug_init() instead.
Signed-off-by: NChris Brand <chris.brand@linaro.org>
Reviewed-by: NMatt Porter <mporter@linaro.org>
Reviewed-by: NAlex Elder <elder@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

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: NSylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMike 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: NPeter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: NMike 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 27b8d5f7 ("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: NSachin Kamat <sachin.kamat@samsung.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: NMike 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: NPeter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Commit 99cbd064 ("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: NArnd Bergmann <arnd@arndb.de>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

  - Limit ruler to 80 characters (was: 81),
  - Widen rate column by 1 for nicer spacing,
  - Right-align numbers and their column headers,
  - Move a newline to reduce the number of seq_printf() calls,
  - Use set_puts() for fixed strings.

Before:

   clock                        enable_cnt  prepare_cnt  rate        accuracy
---------------------------------------------------------------------------------
 extal                          2           2            20000000   0
    thermal                     1           1            20000000   0
    cp                          0           0            10000000   0
       tpu0                     0           0            10000000   0
       tmu0                     0           0            10000000   0
    main                        1           1            20000000   0
       pll3                     0           0            1600000000 0
          ddr                   0           0            200000000  0
          zb3d2                 0           0            200000000  0
          zb3                   0           0            400000000  0
       pll1                     4           4            1560000000 0
          oscclk                0           0            126953     0
          rclk                  1           1            31738      0
             cmt1               0           0            31738      0
             cmt0               1           1            31738      0
          imp                   0           0            390000000  0

After:

   clock                         enable_cnt  prepare_cnt        rate   accuracy
--------------------------------------------------------------------------------
 extal                                    2            2    20000000          0
    thermal                               1            1    20000000          0
    cp                                    0            0    10000000          0
       tpu0                               0            0    10000000          0
       tmu0                               0            0    10000000          0
    main                                  1            1    20000000          0
       pll3                               0            0  1600000000          0
          ddr                             0            0   200000000          0
          zb3d2                           0            0   200000000          0
          zb3                             0            0   400000000          0
       pll1                               4            4  1560000000          0
          oscclk                          0            0      126953          0
          rclk                            1            1       31738          0
             cmt1                         0            0       31738          0
             cmt0                         1            1       31738          0
          imp                             0            0   390000000          0
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMike 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: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike 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: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike 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: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

When a clock is unregsitered, we iterate over the list of
children and reparent them to NULL (i.e. orphan list). While
iterating the list, we should use the safe iterators because the
children list for this clock is changing when we reparent the
children to NULL. Failure to iterate safely can lead to slab
corruption like this:

=============================================================================
BUG kmalloc-128 (Not tainted): Poison overwritten
-----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: 0xed0c4900-0xed0c4903. First byte 0x0 instead of 0x6b
INFO: Allocated in clk_register+0x20/0x1bc age=297 cpu=2 pid=70
 __slab_alloc.isra.39.constprop.42+0x410/0x454
 kmem_cache_alloc_trace+0x200/0x24c
 clk_register+0x20/0x1bc
 devm_clk_register+0x34/0x68
 0xbf0000f0
 platform_drv_probe+0x18/0x48
 driver_probe_device+0x94/0x360
 __driver_attach+0x94/0x98
 bus_for_each_dev+0x54/0x88
 bus_add_driver+0xe8/0x204
 driver_register+0x78/0xf4
 do_one_initcall+0xc4/0x17c
 load_module+0x19ac/0x2294
 SyS_init_module+0xa4/0x110
 ret_fast_syscall+0x0/0x48
INFO: Freed in clk_unregister+0xd4/0x140 age=23 cpu=2 pid=73
 __slab_free+0x38/0x41c
 clk_unregister+0xd4/0x140
 release_nodes+0x164/0x1d8
 __device_release_driver+0x60/0xb0
 driver_detach+0xb4/0xb8
 bus_remove_driver+0x5c/0xc4
 SyS_delete_module+0x148/0x1d8
 ret_fast_syscall+0x0/0x48
INFO: Slab 0xeec50b90 objects=25 used=0 fp=0xed0c5400 flags=0x4080
INFO: Object 0xed0c48c0 @offset=2240 fp=0xed0c4a00

Bytes b4 ed0c48b0: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
Object ed0c48c0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c48d0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c48e0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c48f0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c4900: 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  ....kkkkkkkkkkkk
Object ed0c4910: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c4920: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
Object ed0c4930: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5  kkkkkkkkkkkkkkk.
Redzone ed0c4940: bb bb bb bb                                      ....
Padding ed0c49e8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
Padding ed0c49f8: 5a 5a 5a 5a 5a 5a 5a 5a                          ZZZZZZZZ
CPU: 3 PID: 75 Comm: mdev Tainted: G    B         3.14.0-11033-g2054ba5ca781 #35
[<c0014be0>] (unwind_backtrace) from [<c0012240>] (show_stack+0x10/0x14)
[<c0012240>] (show_stack) from [<c04b74a0>] (dump_stack+0x70/0xbc)
[<c04b74a0>] (dump_stack) from [<c00f7a78>] (check_bytes_and_report+0xbc/0x100)
[<c00f7a78>] (check_bytes_and_report) from [<c00f7c48>] (check_object+0x18c/0x218)
[<c00f7c48>] (check_object) from [<c00f7efc>] (__free_slab+0x104/0x144)
[<c00f7efc>] (__free_slab) from [<c04b6668>] (__slab_free+0x3dc/0x41c)
[<c04b6668>] (__slab_free) from [<c014c008>] (load_elf_binary+0x88/0x12b4)
[<c014c008>] (load_elf_binary) from [<c0105a44>] (search_binary_handler+0x78/0x18c)
[<c0105a44>] (search_binary_handler) from [<c0106fc0>] (do_execve+0x490/0x5dc)
[<c0106fc0>] (do_execve) from [<c0036b8c>] (____call_usermodehelper+0x134/0x168)
[<c0036b8c>] (____call_usermodehelper) from [<c000f048>] (ret_from_fork+0x14/0x2c)
FIX kmalloc-128: Restoring 0xed0c4900-0xed0c4903=0x6b

Fixes: fcb0ee6a (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: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
Cc: stable@vger.kernel.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: fcb0ee6a (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: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>
Cc: stable@vger.kernel.org

Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

This restores the default clocks registration order as parsed from
devicetree, i.e. as before commit 1771b10d
"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: NSylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMike 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: NAlex Elder <elder@linaro.org>
Signed-off-by: NMike 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: NSascha Hauer <s.hauer@pengutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NMike 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: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Ensure clk->kref is dereferenced only when clk is not NULL.
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NMike 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: NJean-Francois Moine <moinejf@free.fr>
Reviewed-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NMike 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: NSören Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: NSören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NMike 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: NBen Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NMike 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: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Allow drivers to be compiled as modules by exporting more clock
provider functions.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike 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: NTero Kristo <t-kristo@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NMike 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: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike 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: NMike 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: NBoris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>