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path: root/drivers/clk/clk.c
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2015-04-12clk: check ->determine/round_rate() return value in clk_calc_new_ratesBoris Brezillon
->determine_rate() and ->round_rate() can return the closest rate to the requested one or an error code. clk_calc_new_rates is assuming these functions can't return a negative value, which leads to a undefined behavior when the clk implementation returns such an error code. Fix this by returning NULL in case ->determine_rate() or ->round_rate() returned an error code. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12Merge branch 'clk-fixes' into clk-nextStephen Boyd
2015-03-12clk: Replace of_clk_get_by_clkspec() with of_clk_get_from_provider()Stephen Boyd
of_clk_get_by_clkspec() has the same function signature as of_clk_get_from_provider() struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec) struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) except of_clk_get_by_clkspec() checks to make sure clkspec is not NULL. Let's remove of_clk_get_by_clkspec() and replace the callers of it (clkconf.c) with of_clk_get_from_provider(). Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-12clk: Rename child_node to clks_node to avoid confusionStephen Boyd
The child_node member of struct clk is named the same as the child_node member of struct clk_core. Let's rename the struct clk's member to clks_node to avoid getting confused with the child_node member of struct clk_core and to match the name of the list head, clks. Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Alban Browaeys <alban.browaeys@gmail.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-12clk: clk_set_parent() with current parent shouldn't failStephen Boyd
If a driver calls clk_set_parent(clk, parent) and parent is the current parent of clk we shouldn't fail in any case. Unfortunately if clk is a read-only mux we return -ENOSYS because we think we can't change the parent, except for in this special case where we don't actually need to change the parent at all. Return 0 in such a situation. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12clk: Add tracepoints for hardware operationsStephen Boyd
It's useful to have tracepoints around operations that change the hardware state so that we can debug clock hardware performance and operations. Four basic types of events are supported: on/off events for enable, disable, prepare, unprepare that only record an event and a clock name, rate changing events for clk_set_{min_,max_}rate{_range}(), phase changing events for clk_set_phase() and parent changing events for clk_set_parent(). Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12clk: Missing set_phase op is an errorStephen Boyd
If a clock's clk_ops doesn't have the set_phase op set we should return an error from clk_set_phase(). This way clock consumers know that when they tried to set a phase it didn't work, as opposed to the current behavior where the return value is 0 meaning success. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-12clk: Use lockdep asserts to find missing hold of prepare_lockKrzysztof Kozlowski
Add lockdep asserts for holding the prepare_lock to all functions marking this as a requirement in description. Add this to private and exported functions so all locking misuse could be detected during debugging. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-03-11clk: introduce clk_is_matchMichael Turquette
Some drivers compare struct clk pointers as a means of knowing if the two pointers reference the same clock hardware. This behavior is dubious (drivers must not dereference struct clk), but did not cause any regressions until the per-user struct clk patch was merged. Now the test for matching clk's will always fail with per-user struct clk's. clk_is_match is introduced to fix the regression and prevent drivers from comparing the pointers manually. Fixes: 035a61c314eb ("clk: Make clk API return per-user struct clk instances") Cc: Russell King <linux@arm.linux.org.uk> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Michael Turquette <mturquette@linaro.org> [arnd@arndb.de: Fix COMMON_CLK=N && HAS_CLK=Y config] Signed-off-by: Arnd Bergmann <arnd@arndb.de> [sboyd@codeaurora.org: const arguments to clk_is_match() and remove unnecessary ternary operation] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-03-11clk: don't export static symbolJulia Lawall
The semantic patch that fixes this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r@ type T; identifier f; @@ static T f (...) { ... } @@ identifier r.f; declarer name EXPORT_SYMBOL_GPL; @@ -EXPORT_SYMBOL_GPL(f); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Fixes: 035a61c314eb "clk: Make clk API return per-user struct clk instances" Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-02-21Merge tag 'clk-for-linus-3.20' of ↵Linus Torvalds
git://git.linaro.org/people/mike.turquette/linux Pull clock framework updates from Mike Turquette: "The clock framework changes contain the usual driver additions, enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based devices. Additionally the framework core underwent a bit of surgery with two major changes: - The boundary between the clock core and clock providers (e.g clock drivers) is now more well defined with dedicated provider helper functions. struct clk no longer maps 1:1 with the hardware clock but is a true per-user cookie which helps us tracker users of hardware clocks and debug bad behavior. - The addition of rate constraints for clocks. Rate ranges are now supported which are analogous to the voltage ranges in the regulator framework. Unfortunately these changes to the core created some breakeage. We think we fixed it all up but for this reason there are lots of last minute commits trying to undo the damage" * tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux: (113 commits) clk: Only recalculate the rate if needed Revert "clk: mxs: Fix invalid 32-bit access to frac registers" clk: qoriq: Add support for the platform PLL powerpc/corenet: Enable CLK_QORIQ clk: Replace explicit clk assignment with __clk_hw_set_clk clk: Add __clk_hw_set_clk helper function clk: Don't dereference parent clock if is NULL MIPS: Alchemy: Remove bogus args from alchemy_clk_fgcs_detr clkdev: Always allocate a struct clk and call __clk_get() w/ CCF clk: shmobile: div6: Avoid division by zero in .round_rate() clk: mxs: Fix invalid 32-bit access to frac registers clk: omap: compile legacy omap3 clocks conditionally clkdev: Export clk_register_clkdev clk: Add rate constraints to clocks clk: remove clk-private.h pci: xgene: do not use clk-private.h arm: omap2+ remove dead clock code clk: Make clk API return per-user struct clk instances clk: tegra: Define PLLD_DSI and remove dsia(b)_mux clk: tegra: Add support for the Tegra132 CAR IP block ...
2015-02-19clk: Only recalculate the rate if neededTomeu Vizoso
We don't really need to recalculate the effective rate of a clock when a per-user clock is removed, if the constraints of the later aren't limiting the requested rate. This was causing problems with clocks that never had a rate set before, as rate_req would be zero. Though this could be considered a bug in the implementation of those clocks, this should be checked somewhere else. Fixes: 1c8e600440c7 ("clk: Add rate constraints to clocks") Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Peter De Schrijver <pdeschrijver@nvidia.com> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-18clk: Don't dereference parent clock if is NULLJavier Martinez Canillas
The clock passed as an argument to clk_mux_determine_rate_flags() has the CLK_SET_RATE_PARENT flag set but it has no parent, then a NULL pointer will tried to be dereferenced. This shouldn't happen since setting that flag for a clock with no parent is a bug but the core should be robust to handle that case. Fixes: 035a61c314eb3 ("clk: Make clk API return per-user struct clk instances") Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-13clk: convert clock name allocations to kstrdup_constAndrzej Hajda
Clock subsystem frequently performs duplication of strings located in read-only memory section. Replacing kstrdup by kstrdup_const allows to avoid such operations. Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Mike Turquette <mturquette@linaro.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Tejun Heo <tj@kernel.org> Cc: Greg KH <greg@kroah.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-06clkdev: Always allocate a struct clk and call __clk_get() w/ CCFStephen Boyd
of_clk_get_by_clkspec() returns a struct clk pointer but it doesn't create a new handle for the consumers when we're using the common clock framework. Instead it just returns whatever the clk provider hands out. When the consumers go to call clk_put() we get an Oops. Unable to handle kernel paging request at virtual address 00200200 pgd = c0004000 [00200200] *pgd=00000000 Internal error: Oops: 805 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc1-00104-ga251361a-dirty #992 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) task: ee00b000 ti: ee088000 task.ti: ee088000 PC is at __clk_put+0x24/0xd0 LR is at clk_prepare_lock+0xc/0xec pc : [<c03eef38>] lr : [<c03ec1f4>] psr: 20000153 sp : ee089de8 ip : 00000000 fp : 00000000 r10: ee02f480 r9 : 00000001 r8 : 00000000 r7 : ee031cc0 r6 : ee089e08 r5 : 00000000 r4 : ee02f480 r3 : 00100100 r2 : 00200200 r1 : 0000091e r0 : 00000001 Flags: nzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 4000404a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xee088238) Stack: (0xee089de8 to 0xee08a000) 9de0: ee7c8f14 c03f0ec8 ee089e08 00000000 c0718dc8 00000001 9e00: 00000000 c04ee0f0 ee7e0844 00000001 00000181 c04edb58 ee2bd320 00000000 9e20: 00000000 c011dc5c ee16a1e0 00000000 00000000 c0718dc8 ee16a1e0 ee2bd1e0 9e40: c0641740 ee16a1e0 00000000 ee2bd320 c0718dc8 ee1d3e10 ee1d3e10 00000000 9e60: c0769a88 00000000 c0718dc8 00000000 00000000 c02c3124 c02c310c ee1d3e10 9e80: c07b4eec 00000000 c0769a88 c02c1d0c ee1d3e10 c0769a88 ee1d3e44 00000000 9ea0: c07091dc c02c1eb8 00000000 c0769a88 c02c1e2c c02c0544 ee005478 ee1676c0 9ec0: c0769a88 ee3a4e80 c0760ce8 c02c150c c0669b90 c0769a88 c0746cd8 c0769a88 9ee0: c0746cd8 ee2bc4c0 c0778c00 c02c24e0 00000000 c0746cd8 c0746cd8 c07091f0 9f00: 00000000 c0008944 c04f405c 00000025 ee00b000 60000153 c074ab00 00000000 9f20: 00000000 c074ab90 60000153 00000000 ef7fca5d c050860c 000000b6 c0036b88 9f40: c065ecc4 c06bc728 00000006 00000006 c074ab30 ef7fca40 c0739bdc 00000006 9f60: c0718dbc c0778c00 000000b6 c0718dc8 c06ed598 c06edd64 00000006 00000006 9f80: c06ed598 c003b438 00000000 c04e64f4 00000000 00000000 00000000 00000000 9fa0: 00000000 c04e64fc 00000000 c000e838 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0 [<c03eef38>] (__clk_put) from [<c03f0ec8>] (of_clk_set_defaults+0xe0/0x2c0) [<c03f0ec8>] (of_clk_set_defaults) from [<c02c3124>] (platform_drv_probe+0x18/0xa4) [<c02c3124>] (platform_drv_probe) from [<c02c1d0c>] (driver_probe_device+0x10c/0x22c) [<c02c1d0c>] (driver_probe_device) from [<c02c1eb8>] (__driver_attach+0x8c/0x90) [<c02c1eb8>] (__driver_attach) from [<c02c0544>] (bus_for_each_dev+0x54/0x88) [<c02c0544>] (bus_for_each_dev) from [<c02c150c>] (bus_add_driver+0xd4/0x1d0) [<c02c150c>] (bus_add_driver) from [<c02c24e0>] (driver_register+0x78/0xf4) [<c02c24e0>] (driver_register) from [<c07091f0>] (fimc_md_init+0x14/0x30) [<c07091f0>] (fimc_md_init) from [<c0008944>] (do_one_initcall+0x80/0x1d0) [<c0008944>] (do_one_initcall) from [<c06edd64>] (kernel_init_freeable+0x108/0x1d4) [<c06edd64>] (kernel_init_freeable) from [<c04e64fc>] (kernel_init+0x8/0xec) [<c04e64fc>] (kernel_init) from [<c000e838>] (ret_from_fork+0x14/0x3c) Code: ebfff4ae e5943014 e5942018 e3530000 (e5823000) Let's create a per-user handle here so that clk_put() can properly unlink it and free the handle. Now that we allocate a clk structure here we need to free it if __clk_get() fails so bury the __clk_get() call in __of_clk_get_from_provider(). We need to handle the same problem in clk_get_sys() so export __clk_free_clk() to clkdev.c and do the same thing, except let's use a union to make this code #ifdef free. This fixes the above crash, properly calls __clk_get() when of_clk_get_from_provider() is called, and cleans up the clk structure on the error path of clk_get_sys(). Fixes: 035a61c314eb "clk: Make clk API return per-user struct clk instances" Reported-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Reported-by: Alban Browaeys <alban.browaeys@gmail.com> Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Tested-by: Alban Browaeys <prahal@yahoo.com> Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-02clk: Add rate constraints to clocksTomeu Vizoso
Adds a way for clock consumers to set maximum and minimum rates. This can be used for thermal drivers to set minimum rates, or by misc. drivers to set maximum rates to assure a minimum performance level. Changes the signature of the determine_rate callback by adding the parameters min_rate and max_rate. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> [sboyd@codeaurora.org: set req_rate in __clk_init] Signed-off-by: Michael Turquette <mturquette@linaro.org> [mturquette@linaro.org: min/max rate for sun6i_ahb1_clk_determine_rate migrated clk-private.h changes to clk.c]
2015-02-02clk: remove clk-private.hMichael Turquette
Private clock framework data structures should be private, surprisingly. Now that all platforms and drivers have been updated to remove static initializations of struct clk and struct clk_core objects and all references to clk-private.h have been removed we can move the definitions of these structures into drivers/clk/clk.c and delete the header. Additionally the ugly DEFINE_CLK macros have been removed. Those were used for static definitions of struct clk objects. That practice is no longer allowed. Finally __clk_init is staticized as it is no longer declared in any header. Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-02-02clk: Make clk API return per-user struct clk instancesTomeu Vizoso
Moves clock state to struct clk_core, but takes care to change as little API as possible. struct clk_hw still has a pointer to a struct clk, which is the implementation's per-user clk instance, for backwards compatibility. The struct clk that clk_get_parent() returns isn't owned by the caller, but by the clock implementation, so the former shouldn't call clk_put() on it. Because some boards in mach-omap2 still register clocks statically, their clock registration had to be updated to take into account that the clock information is stored in struct clk_core now. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Michael Turquette <mturquette@linaro.org> [mturquette@linaro.org: adapted clk_has_parent to struct clk_core applied OMAP3+ DPLL fix from Tero & Tony]
2015-01-28clk: Remove __clk_registerTomeu Vizoso
As it has never been used. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-28clk: Remove unneeded NULL checksTomeu Vizoso
As clk_unprepare_unused_subtree and clk_disable_unused_subtree are always called with a valid struct clk. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-27clk: Export phase functionsMaxime Ripard
The phase setter and getter were not exported until now, which was causing build breakages when callers were compiled as module. Export these two functions. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-27clk: Add __clk_mux_determine_rate_closestStephen Boyd
Some clock drivers want to find the closest rate on the input of a mux instead of a rate that's less than or equal to the desired rate. Add a generic mux function to support this. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Kenneth Westfield <kwestfie@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-27clk: Fix debugfs clk removal before initedSrinivas Kandagatla
Some of the clks can be registered & unregistered before the clk related debugfs entries are initialized at late_initcall. In the unregister path checking for only dentry before clk_debug_init() would lead dangling pointers in the debug clk list, because the list is already populated in register path and the clk pointer freed in unregister path. The side effect of not removing it from the list is either a null pointer dereference or if lucky to boot the system, the number of clk entries in debugfs disappear. We could add more checks like if (inited && !clk->dentry) but just removing the check for dentry made more sense as debugfs_remove_recursive() seems to be safe with null pointers. This will ensure that the unregistering clk would be removed from the debug list in all the code paths. Without this patch kernel would crash with log: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0204000 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Tainted: G B 3.19.0-rc3-00007-g412f9ba-dirty #840 Hardware name: Qualcomm (Flattened Device Tree) task: ed948000 ti: ed944000 task.ti: ed944000 PC is at strlen+0xc/0x40 LR is at __create_file+0x64/0x1dc pc : [<c04ee604>] lr : [<c049f1c4>] psr: 60000013 sp : ed945e40 ip : ed945e50 fp : ed945e4c r10: 00000000 r9 : c1006094 r8 : 00000000 r7 : 000041ed r6 : 00000000 r5 : ed4af998 r4 : c11b5e28 r3 : 00000000 r2 : ed945e38 r1 : a0000013 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5787d Table: 8020406a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xed944248) Stack: (0xed945e40 to 0xed946000) 5e40: ed945e7c ed945e50 c049f1c4 c04ee604 c0fc2fa4 00000000 ecb748c0 c11c2b80 5e60: c0beec04 0000011c c0fc2fa4 00000000 ed945e94 ed945e80 c049f3e0 c049f16c 5e80: 00000000 00000000 ed945eac ed945e98 c08cbc50 c049f3c0 ecb748c0 c11c2b80 5ea0: ed945ed4 ed945eb0 c0fc3080 c08cbc30 c0beec04 c107e1d8 ecdf0600 c107e1d8 5ec0: c107e1d8 ecdf0600 ed945f54 ed945ed8 c0208ed4 c0fc2fb0 c026a784 c04ee628 5ee0: ed945f0c ed945ef0 c0f5d600 c04ee604 c0f5d5ec ef7fcc7d c0b40ecc 0000011c 5f00: ed945f54 ed945f10 c026a994 c0f5d5f8 c04ecc00 00000007 ef7fcc95 00000007 5f20: c0e90744 c0dd0884 ed945f54 c106cde0 00000007 c117f8c0 0000011c c0f5d5ec 5f40: c1006094 c100609c ed945f94 ed945f58 c0f5de34 c0208e50 00000007 00000007 5f60: c0f5d5ec be9b5ae0 00000000 c117f8c0 c0af1680 00000000 00000000 00000000 5f80: 00000000 00000000 ed945fac ed945f98 c0af169c c0f5dd2c ed944000 00000000 5fa0: 00000000 ed945fb0 c020f298 c0af168c 00000000 00000000 00000000 00000000 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ebcc6d33 bfffca73 [<c04ee604>] (strlen) from [<c049f1c4>] (__create_file+0x64/0x1dc) [<c049f1c4>] (__create_file) from [<c049f3e0>] (debugfs_create_dir+0x2c/0x34) [<c049f3e0>] (debugfs_create_dir) from [<c08cbc50>] (clk_debug_create_one+0x2c/0x16c) [<c08cbc50>] (clk_debug_create_one) from [<c0fc3080>] (clk_debug_init+0xdc/0x144) [<c0fc3080>] (clk_debug_init) from [<c0208ed4>] (do_one_initcall+0x90/0x1e0) [<c0208ed4>] (do_one_initcall) from [<c0f5de34>] (kernel_init_freeable+0x114/0x1e0) [<c0f5de34>] (kernel_init_freeable) from [<c0af169c>] (kernel_init+0x1c/0xfc) [<c0af169c>] (kernel_init) from [<c020f298>] (ret_from_fork+0x14/0x3c) Code: c0b40ecc e1a0c00d e92dd800 e24cb004 (e5d02000) ---[ end trace b940e45b5e25c1e7 ]--- Fixes: 6314b6796e3c "clk: Don't hold prepare_lock across debugfs creation" Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-24Merge branch 'clk-has-parent' into clk-nextMichael Turquette
2015-01-24clk: Introduce clk_has_parent()Thierry Reding
This new function is similar to clk_set_parent(), except that it doesn't actually change the parent. It merely checks that the given parent clock can be a parent for the given clock. A situation where this is useful is to check that a particular setup is valid before switching to it. One specific use-case for this is atomic modesetting in the DRM framework where setting a mode is divided into a check phase where a given configuration is validated before applying changes to the hardware. Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-20clk: Skip fetching index for single parent clocksStephen Boyd
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: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-17clk: fix possible null pointer dereferenceStanimir Varbanov
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: Stanimir Varbanov <svarbanov@mm-sol.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-15clk: Really fix deadlock with mmap_semStephen Boyd
Commit 6314b6796e3c (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: Russell King <rmk+kernel@arm.linux.org.uk> Fixes: 6314b6796e3c "clk: Don't hold prepare_lock across debugfs creation" Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Michael Turquette <mturquette@linaro.org> [mturquette@linaro.org: removed lockdep_assert]
2014-12-03clk: Change clk_ops->determine_rate to return a clk_hw as the best parentTomeu Vizoso
This is in preparation for clock providers to not have to deal with struct clk. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03clk: change clk_debugfs_add_file to take a struct clk_hwTomeu Vizoso
Instead of struct clk, as this should be only used by providers. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03clk: Don't expose __clk_get_accuracyTomeu Vizoso
As it's only used internally, in drivers/clk/clk.c. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03clk: Don't try to use a struct clk* after it could have been freedTomeu Vizoso
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: Tomeu Vizoso <tomeu.vizoso@collabora.com> Fixes: fcb0ee6a3d33 ("clk: Implement clk_unregister") Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-12-03clk: Remove unused function __clk_get_prepare_countTomeu Vizoso
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-11-19clk: delete a local variable's repeated assignmentZhen Lei
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: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-09-27Merge tag 'sunxi-clocks-for-3.18' of ↵Mike Turquette
git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into clk-next Allwinner Clocks Additions for 3.18 The most important part of this serie is the addition of the phase API to handle the MMC clocks in the Allwinner SoCs. Apart from that, the A23 gained a new mbus driver, and there's a fix for a incorrect divider table on the APB0 clock.
2014-09-27clk: Add a function to retrieve phaseMaxime Ripard
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: Maxime Ripard <maxime.ripard@free-electrons.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Hans de Goede <hdegoede@redhat.com>
2014-09-27clk: introduce clk_set_phase function & callbackMike Turquette
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: Mike Turquette <mturquette@linaro.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Hans de Goede <hdegoede@redhat.com>
2014-09-17Merge branch 'clk-fixes' into clk-nextMike Turquette
2014-09-10clk: Don't hold prepare_lock across debugfs creationStephen Boyd
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: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-09-03clk: prevent erronous parsing of children during rate changeTero Kristo
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: 71472c0c06cf ("clk: add support for clock reparent on set_rate") Signed-off-by: Tero Kristo <t-kristo@ti.com> Reported-by: Nishanth Menon <nm@ti.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-07-29clk: Propagate any error return from debug_init()Chris Brand
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: Chris Brand <chris.brand@linaro.org> Reviewed-by: Matt Porter <mporter@linaro.org> Reviewed-by: Alex Elder <elder@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-07-25clk: Support for clock parents and rates assigned from device treeSylwester Nawrocki
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>
2014-07-02clk: define and export clk_debugs_add_filePeter De Schrijver
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>
2014-07-01clk: Fix build warningsSachin Kamat
‘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>
2014-06-26clk: flatten clk tree in debugfsPeter De Schrijver
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>
2014-06-03clk: export __clk_round_rate for providersArnd Bergmann
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>
2014-05-23clk: Neaten clk_summary outputGeert Uytterhoeven
- 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: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-04-30clk: Ignore error and NULL pointers passed to clk_{unprepare, disable}()Stephen Boyd
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>
2014-04-30clk: Consolidate recalc rate logicStephen Boyd
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>
2014-04-30clk: Don't check for missing ops in clk_set_parent()Stephen Boyd
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>