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path: root/drivers/clk/clk.c
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2016-02-02clk: avoid circular clock topologyMasahiro Yamada1-0/+40
Currently, clk_register() never checks a circular parent looping, but clock providers could register such an insane clock topology. For example, "clk_a" could have "clk_b" as a parent, and vice versa. In this case, clk_core_reparent() creates a circular parent list and __clk_recalc_accuracies() calls itself recursively forever. The core infrastructure should be kind enough to bail out, showing an appropriate error message in such a case. This helps to easily find a bug in clock providers. (uh, I made such a silly mistake when I was implementing my clock providers first. I was upset because the kernel did not respond, without any error message.) This commit adds a new helper function, __clk_is_ancestor(). It returns true if the second argument is a possible ancestor of the first one. If a clock core is a possible ancestor of itself, it would make a loop when it were registered. That should be detected as an error. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: simplify __clk_init_parent()Masahiro Yamada1-34/+4
The translation from the index into clk_core is done by clk_core_get_parent_by_index(). The if-block for num_parents == 1 case is duplicating the code in the clk_core_get_parent_by_index(). Drop the "if (num_parents == 1)" from the special case. Instead, set the index to zero if .get_parent() is missing. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: move checking .get_parent to __clk_core_init()Masahiro Yamada1-7/+7
The .get_parent is mandatory for multi-parent clocks. Move the check to __clk_core_init(), like other callback checkings. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> [sboyd@codeaurora.org: Squashed in error path handling, fix typos in commit message] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: replace pr_warn() with pr_err() for fatal casesMasahiro Yamada1-5/+5
These three cases let clk_register() fail. They should be considered as error messages. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: drop the initial core->parents look-ups from __clk_core_init()Masahiro Yamada1-11/+0
The core->parents is a cache to save expensive clock parent look-ups. It will be filled as needed later. We do not have to do it here. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: simplify clk_core_get_parent_by_index()Masahiro Yamada1-7/+6
Drop the "if (!core->parents)" case and refactor the function a bit because core->parents is always allocated. (Strictly speaking, it is ZERO_SIZE_PTR if core->num_parents == 0, but such a case is omitted by the if-conditional above.) Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: move core->parents allocation to clk_register()Masahiro Yamada1-32/+19
Currently, __clk_core_init() allows failure of the kcalloc() for the core->parents. So, clk_fetch_parent_index() and __clk_init_parent() also try to allocate core->parents in case it has not been allocated yet. Scattering memory allocation here and there makes things complicated. Like other clk_core members, allocate core->parents in clk_register() and let it fail in case of memory shortage. If we cannot allocate such a small piece of memory, the system is already insane. There is no point to postpone the memory allocation. Also, allocate core->parents regardless of core->num_parents. We want it even if core->num_parents == 1 because clk_fetch_parent_index() might be called against the clk_core with a single parent. If core->num_parents == 0, core->parents is set to ZERO_SIZE_PTR. It is harmless because no access happens to core->parents in such a case. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: change sizeof(struct clk *) to sizeof(*core->parents)Masahiro Yamada1-4/+4
Now, the clock parent is not "struct clk *", but "struct clk_core *". Of course, the size of a pointer is always same, but strictly speaking, sizeof(struct clk *) should be sizeof(struct clk_core *) here. This mismatch happened when we split the structure into struct clk and struct clk_core. For the potential possibility of future renaming, sizeof(*core->parents) would be better. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: remove unnecessary !core->parents conditionalMasahiro Yamada1-4/+1
This if-block has been here since the introduction of the common clock framework. Now no clock drivers are statically initialized. core->parent is always NULL at this point. Drop the redundant check and the confusing comment. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: rename __clk_init() into __clk_core_init()Masahiro Yamada1-3/+3
Now this function takes clk_core as its argument. __clk_core_init() would be more suitable for the name of this function. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: change the argument of __clk_init() into pointer to clk_coreMasahiro Yamada1-8/+5
The argument clk_user is used only for the clk_user->core. The rest of this function only takes care of clk_core. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-02-02clk: remove unused first argument of __clk_init()Masahiro Yamada1-3/+2
The "struct device *dev" is not used at all in this function. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-12-24Merge branch 'clk-rockchip' into clk-nextMichael Turquette1-0/+18
2015-12-23clk: add flag for clocks that need to be enabled on rate changesHeiko Stuebner1-0/+18
Some clocks need to be enabled to accept rate changes. This patch adds a new flag CLK_SET_RATE_UNGATE that lets clk_change_rate enable the clock before trying to change the rate and disable it again afterwards. This of course doesn't effect clocks that are already running at that point, as their refcount will only temporarily increase. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Tested-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk> Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk> Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-12-03clk: let of_clk_get_parent_name() fail for invalid clock-indicesMasahiro Yamada1-0/+3
Currently, of_clk_get_parent_name() returns a wrong parent clock name when "clock-indices" property exists and the target index is not found in the property. In this case, NULL should be returned. For example, oscillator { compatible = "myclocktype"; #clock-cells = <1>; clock-indices = <1>, <3>; clock-output-names = "clka", "clkb"; }; consumer { compatible = "myclockconsumer"; clocks = <&oscillator 0>, <&oscillator 1>; }; Currently, of_clk_get_parent_name(consumer_np, 0) returns "clka" (and of_clk_get_parent_name(consumer_np, 1) also returns "clka", this is correct). Because the "clock-indices" in the clock parent does not contain <0>, of_clk_get_parent_name(consumer_np, 0) should return NULL. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-30clk: fix a typo in comment block of clk_notifier_register()Masahiro Yamada1-4/+3
The word "cases" is doubled. Keep decent forms for the following lines. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20clk: Spelling s/derefing/dereferencing/Geert Uytterhoeven1-1/+1
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20clk: use IS_ERR_OR_NULL(hw) instead of !hw || IS_ERR(hw)Masahiro Yamada1-1/+1
This minor refactoring does not change the function behavior. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-11-20clk: remove redundant negative index check in of_clk_get_parent_name()Masahiro Yamada1-3/+0
This if-block can be dropped because the of_parse_phandle_with_args() in the following line returns -EINVAL for negative index. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-26clk: Add clk_hw_is_enabled() for use by clk providersJoachim Eastwood1-0/+5
Add clk_hw_is_enabled() to the provider APIs so clk providers can use a struct clk_hw instead of a struct clk to check if a clk is enabled or not. Signed-off-by: Joachim Eastwood <manabian@gmail.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-22clk: add missing of_node_putJulia Lawall1-1/+4
for_each_matching_node_and_match performs an of_node_get on each iteration, so a break out of the loop requires an of_node_put. A simplified version of the semantic patch that fixes this problem is as follows (http://coccinelle.lip6.fr): // <smpl> @@ expression e1,e2,e; local idexpression np; @@ for_each_matching_node_and_match(np, e1, e2) { ... when != of_node_put(np) when != e = np ( return np; | + of_node_put(np); ? return ...; ) ... } // </smpl> Besides the problem identified by the semantic patch, this patch adds an of_node_get in front of saving np in a field of parent, to account for the fact that this value will be put on going on to the next element in the iteration, and then adds of_node_puts in the two loops where the parent pointer can be freed. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-16clk: Make clk input parameter of __clk_get_name() constGeert Uytterhoeven1-1/+1
When calling __clk_get_name() on a const clock: warning: passing argument 1 of '__clk_get_name' discards 'const' qualifier from pointer target type include/linux/clk-provider.h:613:13: note: expected 'struct clk *' but argument is of type 'const struct clk *' __clk_get_name() does not modify the passed clock, hence make it const. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-16clk: Use %u to format unsigned int in of_clk_src_onecell_get()Geert Uytterhoeven1-1/+1
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-16clk: Make of_clk_get_parent_name() robust with #clock-cells = 1Stephen Boyd1-2/+20
If a clock provider has #clock-cells = 1 and we call of_clk_get_parent_name() on it we may end up returning the name of the provider node if the provider doesn't have a clock-output-names property. This doesn't make sense, especially when you consider that calling of_clk_get_parent_name() on such a node with different indices will return the same name each time. Let's try getting the clock from the framework via of_clk_get() instead, and only fallback to the node name if we have a provider with #clock-cells = 0. This way, we can't hand out the same name for different clocks when we don't actually know their names. Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-09-17Merge branch 'clk-fixes' into clk-nextStephen Boyd1-1/+2
* clk-fixes: drivers: clk: st: Rename st_pll3200c32_407_c0_x into st_pll3200c32_cx_x clk: check for invalid parent index of orphans in __clk_init()
2015-09-17clk: Remove unneeded semicolonsJavier Martinez Canillas1-1/+1
There are cleary typo errors so can be removed. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Acked-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-09-17clk: check for invalid parent index of orphans in __clk_init()Mans Rullgard1-1/+2
If a mux clock is initialised (by hardware or firmware) with an invalid parent, its ->get_parent() can return an out of range index. For example, the generic mux clock attempts to return -EINVAL, which due to the u8 return type ends up a rather large number. Using this index with the parent_names[] array results in an invalid pointer and (usually) a crash in the following strcmp(). This patch adds a check for the parent index being in range, ignoring clocks reporting invalid values. Signed-off-by: Mans Rullgard <mans@mansr.com> Tested-by: Rhyland Klein <rklein@nvidia.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-25clk: remove duplicated code with __clk_set_parent_afterDong Aisheng1-7/+1
__clk_set_parent_after() actually used the second argument then we could put this duplicate logic in there and call it with a different order of arguments in the success vs. error paths in this function. Cc: Mike Turquette <mturquette@linaro.org> Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-25clk: Constify clk_hw argument to provider APIsStephen Boyd1-7/+8
We don't modify the clk_hw argument in these functions, so it's safe to mark it as const. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-25clk: Remove unused provider APIsStephen Boyd1-76/+16
Remove these APIs now that we've converted all users to the replacement struct clk_hw based versions. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-25clk: Add clk_hw_*() APIs for use by clk providersStephen Boyd1-0/+61
clk providers shouldn't need to use the consumer APIs (clk.h). Add provider APIs to replace the __clk_*() APIs that take a struct clk_hw as their first argument instead of a struct clk. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-12clk: track the orphan status of clocks and their childrenHeiko Stuebner1-3/+30
While children of orphan clocks are not carried in the orphan-list itself, they're nevertheless orphans in their own right as they also don't have an input-rate available. To ease tracking if a clock is an orphan or has an orphan in its parent path introduce an orphan field into struct clk and update it and the fields in child-clocks when a clock gets added or removed from the orphan-list. Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Alex Elder <elder@linaro.org> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: kernel@pengutronix.de Cc: Zhangfei Gao <zhangfei.gao@linaro.org> Cc: Santosh Shilimkar <ssantosh@kernel.org> Cc: Chao Xie <chao.xie@marvell.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Andrew Bresticker <abrestic@chromium.org> Cc: Robert Jarzmik <robert.jarzmik@free.fr> Cc: Georgi Djakov <georgi.djakov@linaro.org> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Barry Song <baohua@kernel.org> Cc: Dinh Nguyen <dinguyen@opensource.altera.com> Cc: Viresh Kumar <viresh.linux@gmail.com> Cc: Gabriel FERNANDEZ <gabriel.fernandez@st.com> Cc: emilio@elopez.com.ar Cc: Peter De Schrijver <pdeschrijver@nvidia.com> Cc: Tero Kristo <t-kristo@ti.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Michal Simek <michal.simek@xilinx.com> [sboyd@codeaurora.org: s/clk/core/ in new function] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28clk: Silence warnings about lock imbalancesStephen Boyd1-1/+6
The recursive spinlock implementation trips up sparse and it complains that these functions have lock imbalances. That isn't really true though, so add some __acquires() and __releases() information so that sparse is quiet. drivers/clk/clk.c:116:22: warning: context imbalance in 'clk_enable_lock' - wrong count at exit drivers/clk/clk.c:141:9: warning: context imbalance in 'clk_enable_unlock' - unexpected unlock Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28Merge branch 'cleanup-clk-h-includes' into clk-nextStephen Boyd1-0/+1
* cleanup-clk-h-includes: (62 commits) clk: Remove clk.h from clk-provider.h clk: h8300: Remove clk.h and clkdev.h includes clk: at91: Include clk.h and slab.h clk: ti: Switch clk-provider.h include to clk.h clk: pistachio: Include clk.h clk: ingenic: Include clk.h clk: si570: Include clk.h clk: moxart: Include clk.h clk: cdce925: Include clk.h clk: Include clk.h in clk.c clk: zynq: Include clk.h clk: ti: Include clk.h clk: sunxi: Include clk.h and remove unused clkdev.h includes clk: st: Include clk.h clk: qcom: Include clk.h clk: highbank: Include clk.h clk: bcm: Include clk.h clk: versatile: Remove clk.h and clkdev.h includes clk: ux500: Remove clk.h and clkdev.h includes clk: tegra: Properly include clk.h ...
2015-07-28clk: Allow providers to configure min/max ratesStephen Boyd1-2/+14
clk providers are using the consumer APIs to set min/max rates on the clock they're providing. To encourage clk providers to move away from the consumer APIs, add a provider API to set the min/max rate of a clock. The assumption is that this is done before the clock can be requested via clk_get() and that the clock rate is already within the boundaries of the min/max that's configured. Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28Merge branch 'clk-determine-rate-struct' into clk-nextStephen Boyd1-80/+99
* clk-determine-rate-struct: clk: fix some determine_rate implementations clk: change clk_ops' ->determine_rate() prototype
2015-07-28clk: fix some determine_rate implementationsBoris Brezillon1-0/+3
Some determine_rate implementations are not returning an error when they failed to adapt the rate according to the rate request. Fix them so that they return an error instead of silently returning 0. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> CC: Jonathan Corbet <corbet@lwn.net> CC: Tony Lindgren <tony@atomide.com> CC: Ralf Baechle <ralf@linux-mips.org> CC: "Emilio López" <emilio@elopez.com.ar> CC: Maxime Ripard <maxime.ripard@free-electrons.com> Cc: Tero Kristo <t-kristo@ti.com> CC: Peter De Schrijver <pdeschrijver@nvidia.com> CC: Prashant Gaikwad <pgaikwad@nvidia.com> CC: Stephen Warren <swarren@wwwdotorg.org> CC: Thierry Reding <thierry.reding@gmail.com> CC: Alexandre Courbot <gnurou@gmail.com> CC: linux-doc@vger.kernel.org CC: linux-kernel@vger.kernel.org CC: linux-arm-kernel@lists.infradead.org CC: linux-omap@vger.kernel.org CC: linux-mips@linux-mips.org CC: linux-tegra@vger.kernel.org Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28clk: change clk_ops' ->determine_rate() prototypeBoris Brezillon1-80/+96
Clock rates are stored in an unsigned long field, but ->determine_rate() (which returns a rounded rate from a requested one) returns a long value (errors are reported using negative error codes), which can lead to long overflow if the clock rate exceed 2Ghz. Change ->determine_rate() prototype to return 0 or an error code, and pass a pointer to a clk_rate_request structure containing the expected target rate and the rate constraints imposed by clk users. The clk_rate_request structure might be extended in the future to contain other kind of constraints like the rounding policy, the maximum clock inaccuracy or other things that are not yet supported by the CCF (power consumption constraints ?). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> CC: Jonathan Corbet <corbet@lwn.net> CC: Tony Lindgren <tony@atomide.com> CC: Ralf Baechle <ralf@linux-mips.org> CC: "Emilio López" <emilio@elopez.com.ar> CC: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Tero Kristo <t-kristo@ti.com> CC: Peter De Schrijver <pdeschrijver@nvidia.com> CC: Prashant Gaikwad <pgaikwad@nvidia.com> CC: Stephen Warren <swarren@wwwdotorg.org> CC: Thierry Reding <thierry.reding@gmail.com> CC: Alexandre Courbot <gnurou@gmail.com> CC: linux-doc@vger.kernel.org CC: linux-kernel@vger.kernel.org CC: linux-arm-kernel@lists.infradead.org CC: linux-omap@vger.kernel.org CC: linux-mips@linux-mips.org CC: linux-tegra@vger.kernel.org [sboyd@codeaurora.org: Fix parent dereference problem in __clk_determine_rate()] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Romain Perier <romain.perier@gmail.com> Signed-off-by: Heiko Stuebner <heiko@sntech.de> [sboyd@codeaurora.org: Folded in fix from Heiko for fixed-rate clocks without parents or a rate determining op] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-20clk: Include clk.h in clk.cStephen Boyd1-0/+1
This file implements the clk API and so it should include clk.h directly instead of indirectly including it through clk-provider.h. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-08clk: Move clk_provider_list to scope of function using itStephen Boyd1-2/+1
The list isn't used after of_clk_init() is called, so we don't need to keep an empty list around after init. Put the list on the stack. Cc: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-08clk: Check for allocation errors in of_clk_init()Stephen Boyd1-2/+11
Dan Carpenter reports that we don't check the allocation here for failure. Add a failure check and free any previously allocated providers from the clk_provider_list. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-06-20Merge tag 'tegra-for-4.2-clk' of ↵Michael Turquette1-0/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into clk-next clk: tegra: Changes for v4.2-rc1 This contains the EMC clock driver that's been exhaustively reviewed and tested. It also includes a change to the clock core that allows a clock provider to perform low-level reparenting of clocks. This is required by the EMC clock driver because the reparenting needs to be done at a very specific point in time during the EMC frequency switch.
2015-06-20Merge branch 'clk-exynos-cpu-clk' into clk-nextMichael Turquette1-0/+3
Folded into this merge commit is a build error fix: s/clk/core in clk_change_rate due to the new struct clk_core
2015-06-20clk: add CLK_RECALC_NEW_RATES clock flag for Exynos cpu clock supportBartlomiej Zolnierkiewicz1-0/+3
This flag is needed to fix the issue with wrong dividers being setup by Common Clock Framework when using the new Exynos cpu clock support. The issue happens because clk_core_set_rate_nolock() calls clk_calc_new_rates(clk, rate) before both pre/post clock notifiers have a chance to run. In case of Exynos cpu clock support pre/post clock notifiers are registered for mout_apll clock which is a parent of armclk cpu clock and dividers are modified in both pre and post clock notifier. This results in wrong dividers values being later programmed by clk_change_rate(top). To workaround the problem CLK_RECALC_NEW_RATES flag is added and it is set for mout_apll clock later so the correct divider values are re-calculated after both pre and post clock notifiers had run. For example when using "performance" governor on Exynos4210 Origen board the cpufreq-dt driver requests to change the frequency from 1000MHz to 1200MHz and after the change state of the relevant clocks is following: Without use of CLK_GET_RATE_NOCACHE flag: fout_apll rate: 1200000000 fout_apll_div_2 rate: 600000000 mout_clkout_cpu rate: 600000000 div_clkout_cpu rate: 600000000 clkout_cpu rate: 600000000 mout_apll rate: 1200000000 armclk rate: 1200000000 mout_hpm rate: 1200000000 div_copy rate: 300000000 div_hpm rate: 300000000 mout_core rate: 1200000000 div_core rate: 1200000000 div_core2 rate: 1200000000 arm_clk_div_2 rate: 600000000 div_corem0 rate: 300000000 div_corem1 rate: 150000000 div_periph rate: 300000000 div_atb rate: 300000000 div_pclk_dbg rate: 150000000 sclk_apll rate: 1200000000 sclk_apll_div_2 rate: 600000000 With use of CLK_GET_RATE_NOCACHE flag: fout_apll rate: 1200000000 fout_apll_div_2 rate: 600000000 mout_clkout_cpu rate: 600000000 div_clkout_cpu rate: 600000000 clkout_cpu rate: 600000000 mout_apll rate: 1200000000 armclk rate: 1200000000 mout_hpm rate: 1200000000 div_copy rate: 200000000 div_hpm rate: 200000000 mout_core rate: 1200000000 div_core rate: 1200000000 div_core2 rate: 1200000000 arm_clk_div_2 rate: 600000000 div_corem0 rate: 300000000 div_corem1 rate: 150000000 div_periph rate: 300000000 div_atb rate: 240000000 div_pclk_dbg rate: 120000000 sclk_apll rate: 150000000 sclk_apll_div_2 rate: 75000000 Without this change cpufreq-dt driver showed ~10 mA larger energy consumption when compared to cpufreq-exynos one when "performance" cpufreq governor was used on Exynos4210 SoC based Origen board. This issue was probably meant to be workarounded by use of CLK_GET_RATE_NOCACHE and CLK_DIVIDER_READ_ONLY clock flags in the original Exynos cpu clock patchset (in "[PATCH v12 6/6] clk: samsung: remove unused clock aliases and update clock flags" patch) but usage of these flags is not sufficient to fix the issue observed. Cc: Thomas Abraham <thomas.ab@samsung.com> Cc: Tomasz Figa <tomasz.figa@gmail.com> Cc: Mike Turquette <mturquette@linaro.org> Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2015-06-11clk: Move debug_node field under DEBUG_FS flag in struct clk_coreMaxime Coquelin1-1/+1
The debug_node field is only used when DEBUG_FS config is selected, so declare it only if DEBUG_FS is selected. Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-06-06clk: of: helper for filling parent clock array and return num of parentsDinh Nguyen1-0/+21
Sprinkled all through the platform clock drivers are code like this to fill the clock parent array: for (i = 0; i < num_parents; ++i) parent_names[i] = of_clk_get_parent_name(np, i); The of_clk_parent_fill() will do the same as the code above, and while at it, return the number of parents as well since the logic of the function is to the walk the clock node to look for the parent. Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com> [sboyd@codeaurora.org: Fixed kernel-doc] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-21clk: Fix typo in clk_register() commentShailendra Verma1-1/+1
Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-15clk: Silence sparse warnings about __clk_{get,put}()Stephen Boyd1-0/+1
drivers/clk/clk.c:2700:5: warning: symbol '__clk_get' was not declared. Should it be static? drivers/clk/clk.c:2713:6: warning: symbol '__clk_put' was not declared. Should it be static? Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-13clk: Expose clk_hw_reparent() to providersTomeu Vizoso1-0/+8
To be used by clock implementations for switching to a new parent during rate change. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2015-05-07clk: Add some more lockdep assertionsStephen Boyd1-0/+8
We don't check to make sure the enable_lock is held across enable/disable and we don't check if the prepare_lock is held across prepare/unprepare. Add some asserts to catch any future locking problems. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>