kernel.git/drivers/clk/clk.c, branch linux-3.8.y

clk: introduce optional disable_unused callback

2012-12-11T06:35:02Z

Some gate clocks have special needs which must be handled during the disable-unused clocks sequence. These needs might be driven by software due to the fact that we're disabling a clock outside of the normal clk_disable path and a clk's enable_count will not be accurate. On the other hand a specific hardware programming sequence might need to be followed for this corner case. This change is needed for the upcoming OMAP port to the common clock framework. Specifically, it is undesirable to treat the disable-unused path identically to the normal clk_disable path since other software layers are involved. In this case OMAP's clockdomain code throws WARNs and bails early due to the clock's enable_count being set to zero. A custom callback mitigates this problem nicely. Cc: Paul Walmsley Acked-by: Ulf Hansson Acked-by: Linus Walleij Signed-off-by: Mike Turquette

clk: clock multiplexers may register out of order

2012-11-26T19:14:45Z

When a clock, C is initialised any orphan clocks listing C as a possible parent are reparented to it regardless of the parent requested by the orphan's get_parent() operation. This means that multiplexers registered before their parents are reparented to the first parent subsequently declared, regardless of the selection made by the hardware registers. For example: static const char *sel[] = { "srcA", "srcB", "dummy", "srcC" }; child = clk_register_mux(NULL, "child", sel, ARRAY_SIZE(sel), ...); clk_register_fixed(NULL, "dummy", ...); clk_register_fixed(NULL, "srcA", ...); clk_register_fixed(NULL, "srcB", ...); clk_register_fixed(NULL, "srcC", ...); Causes child's parent to always be "dummy". To fix this, when an orphanned clock has a get_parent() operation, only reparent to the clock indicated by get_parent(). Signed-off-by: Martin Fuzzey Signed-off-by: Mike Turquette [mturquette@linaro.org: improve $SUBJECT]

clk: Add devm_clk_{register,unregister}()

2012-10-29T18:12:46Z

Some clock drivers can be simplified if devres takes care of unregistering any registered clocks along error paths. Introduce devm_clk_register() so that clock drivers get unregistration for free along with simplified error paths. Signed-off-by: Stephen Boyd Signed-off-by: Mike Turquette

clk: Don't return negative numbers for unsigned values with !clk

2012-10-29T18:05:03Z

Some of the helper functions return negative error codes if passed a NULL clock. This can lead to confusing behavior when the expected return value is unsigned. Fix up these accessors so that they return unsigned values (or bool in the case of is_enabled). This way we can't interpret NULL clocks as having valid and interesting values. Signed-off-by: Stephen Boyd Signed-off-by: Mike Turquette

clk: add of_clk_src_onecell_get() support

2012-09-08T01:30:19Z

For those SoCs that have hundreds of clock outputs, their clock DT bindings could reasonably define #clock-cells as 1 and require the client device specify the index of the clock it consumes in the cell of its "clocks" phandle. Add a generic of_clk_src_onecell_get() function for this purpose. Signed-off-by: Shawn Guo Reviewed-by: Rob Herring Signed-off-by: Mike Turquette

clk: Provide option for clk_get_rate to issue hw for new rate

2012-09-07T00:56:22Z

By using CLK_GET_RATE_NOCACHE flag, we tell the clk_get_rate API to issue the hw for an updated clock rate. This can be used for a clock which rate may be updated without a client necessary modifying it. Signed-off-by: Ulf Hansson Signed-off-by: Mike Turquette

clk: validate pointer in __clk_disable()

2012-07-31T00:25:13Z

clk_get() returns -ENOENT on error and some careless caller might dereference it without error checking: In mxc_rnga_remove(): struct clk *clk = clk_get(&pdev->dev, "rng"); // ... clk_disable(clk); Since it's insane to audit the lots of existing and future clk users, let's add a check in the callee to avoid kernel panic and warn about any buggy user. Cc: Russell King Cc: Paul Gortmaker Cc: Viresh Kumar Cc: viresh kumar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

clk: add DT clock binding support

2012-07-12T00:58:45Z

Based on work 1st by Ben Herrenschmidt and Jeremy Kerr, then by Grant Likely, this patch adds support to clk_get to allow drivers to retrieve clock data from the device tree. Platforms scan for clocks in DT with of_clk_init and a match table, and the register a provider through of_clk_add_provider. The provider's clk_src_get function will be called when a device references the provider's OF node for a clock reference. v6 (Rob Herring): - Return error values instead of NULL to match clock framework expectations v5 (Rob Herring): - Move from drivers/of into common clock subsystem - Squashed "dt/clock: add a simple provider get function" and "dt/clock: add function to get parent clock name" - Rebase to 3.4-rc1 - Drop CONFIG_OF_CLOCK and just use CONFIG_OF - Add missing EXPORT_SYMBOL to various functions - s/clock-output-name/clock-output-names/ - Define that fixed-clock binding is a single output v4 (Rob Herring): - Rework for common clk subsystem - Add of_clk_get_parent_name function v3: - Clarified documentation v2: - fixed errant ';' causing compile error - Editorial fixes from Shawn Guo - merged in adding lookup to clkdev - changed property names to match established convention. After working with the binding a bit it really made more sense to follow the lead of 'reg', 'gpios' and 'interrupts' by making the input simply 'clocks' & 'clock-names' instead of 'clock-input-*', and to only use clock-output* for the producer nodes. (Sorry Shawn, this will mean you need to change some code, but it should be trivial) - Add ability to inherit clocks from parent nodes by using an empty 'clock-ranges' property. Useful for busses. I could use some feedback on the new property name, 'clock-ranges' doesn't feel right to me. Signed-off-by: Grant Likely Signed-off-by: Rob Herring Reviewed-by: Shawn Guo Cc: Sascha Hauer Signed-off-by: Mike Turquette

clk: cache parent clocks only for muxes

2012-07-11T22:36:45Z

caching parent clocks makes sense only when a clock has more than one parent (mux clocks). Avoid doing this for every other clock. Signed-off-by: Rajendra Nayak [mturquette@linaro.org: removed extra parentheses] Signed-off-by: Mike Turquette

clk: fix parent validation in __clk_set_parent()

2012-07-03T19:05:14Z

The below commit introduced a bug in __clk_set_parent() which could cause it to *skip* the parent validation which makes sure the parent passed to the api is a valid one. commit 7975059db572eb47f0fb272a62afeae272a4b209 Author: Rajendra Nayak Date: Wed Jun 6 14:41:31 2012 +0530 clk: Allow late cache allocation for clk->parents This was identified by the following compiler warning.. drivers/clk/clk.c: In function '__clk_set_parent': drivers/clk/clk.c:1083:5: warning: 'i' may be used uninitialized in this function [-Wuninitialized] .. as reported by Marc Kleine-Budde. There were various options discussed on how to fix this, one being initing 'i' to clk->num_parents, but the below approach was found to be more appropriate as it also makes the 'parent validation' code simpler to read. Reported-by: Marc Kleine-Budde Signed-off-by: Rajendra Nayak Signed-off-by: Mike Turquette Cc: stable@kernel.org