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path: root/drivers/clk/clk.c
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2012-05-15clk: Fix CLK_SET_RATE_GATE flag validation in clk_set_rate().Saravana Kannan
The clk_set_rate() code shouldn't check the clock's enable count when validating CLK_SET_RATE_GATE flag since the enable count could change after the validation. Similar to clk_set_parent(), it should instead check the prepare count. The prepare count should go to zero only when the end user expects the clock to not be enabled in the future. Since the code already grabs the prepare count before validation, it's not possible for prepare count to change after validation and by association not possible for a well behaving end user to enable the clock while the set rate is in progress. Signed-off-by: Saravana Kannan <skannan@codeaurora.org> Reviewed-by: Richard Zhao <richard.zhao@freescale.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-05-15clk: Provide dummy clk_unregister()Mark Brown
While there's no actual implementation behind it having the call to use in drivers makes them feel neater from a driver author point of view. An actual implementation can wait for someone who needs to use the function in a real system. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> [mturquette@linaro.org: void return type instead of int -EINVAL] Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-05-08clk: remove COMMON_CLK_DISABLE_UNUSEDMike Turquette
Exposing this option generates confusion and incorrect behavior for single-image builds across platforms. Enable this behavior permanently. Signed-off-by: Mike Turquette <mturquette@linaro.org> Acked-by: Saravana Kannan <skannan@codeaurora.org>
2012-05-08clk: prevent spurious parent rate propagationMike Turquette
Patch 'clk: always pass parent_rate into .round_rate' made a subtle change to the semantics of .round_rate. It is now expected for the parent's rate to always be passed in, simplifying the implemenation of various .round_rate callback definitions. However the patch also introduced a bug in clk_calc_new_rates whereby a clock without the CLK_SET_RATE_PARENT flag set could still propagate a rate change up to a parent clock if the the .round_rate callback modified the &best_parent_rate value in any way. This patch fixes the issue at the framework level (in clk_calc_new_rates) by specifically handling the case where the CLK_SET_RATE_PARENT flag is not set. Signed-off-by: Mike Turquette <mturquette@linaro.org> Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-05-01clk: clk_set_rate() must fail if CLK_SET_RATE_GATE is set and clk is enabledViresh Kumar
This is well documented but isn't implemented. clk_set_rate() must check if flags have CLK_SET_RATE_GATE bit set and is enabled too. Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-05-01clk: Use a separate struct for holding init data.Saravana Kannan
Create a struct clk_init_data to hold all data that needs to be passed from the platfrom specific driver to the common clock framework during clock registration. Add a pointer to this struct inside clk_hw. This has several advantages: * Completely hides struct clk from many clock platform drivers and static clock initialization code that don't care for static initialization of the struct clks. * For platforms that want to do complete static initialization, it removed the need to directly mess with the struct clk's fields while still allowing to statically allocate struct clk. This keeps the code more future proof even if they include clk-private.h. * Simplifies the generic clk_register() function and allows adding optional fields in the future without modifying the function signature. * Simplifies the static initialization of clocks on all platforms by removing the need for forward delcarations or convoluted macros. Signed-off-by: Saravana Kannan <skannan@codeaurora.org> [mturquette@linaro.org: kept DEFINE_CLK_* macros and __clk_init] Signed-off-by: Mike Turquette <mturquette@linaro.org> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Jeremy Kerr <jeremy.kerr@canonical.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergman <arnd.bergmann@linaro.org> Cc: Paul Walmsley <paul@pwsan.com> Cc: Shawn Guo <shawn.guo@freescale.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Jamie Iles <jamie@jamieiles.com> Cc: Richard Zhao <richard.zhao@linaro.org> Cc: Saravana Kannan <skannan@codeaurora.org> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Linus Walleij <linus.walleij@stericsson.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Cc: Deepak Saxena <dsaxena@linaro.org> Cc: Grant Likely <grant.likely@secretlab.ca>
2012-04-24clk: Don't set clk->new_rate twiceViresh Kumar
if (!clk->ops->round_rate && (clk->flags & CLK_SET_RATE_PARENT)) is true, then we don't need to set clk->new_rate here, as we will call clk_calc_subtree() afterwards and it also sets clk->new_rate. Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: propagate round_rate for CLK_SET_RATE_PARENT caseShawn Guo
Need to propagate round_rate call for the clk that has no .round_rate operation but with flag CLK_SET_RATE_PARENT set. For example, clk_mux is a clk with no .round_rate operation. However, it could likely be in a clk_set_rate propagation path, saying it has parent clk who has .round_rate and .set_rate operations. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: pass parent_rate into .set_rateShawn Guo
For most of .set_rate implementation, parent_rate will be used, so just like passing parent_rate into .recalc_rate, let's pass parent_rate into .set_rate too. It also updates the kernel doc for .set_rate ops. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: always pass parent_rate into .round_rateShawn Guo
The parent_rate will likely be used by most .round_rate implementation no matter whether flag CLK_SET_RATE_PARENT is set or not, so let's always pass parent_rate into .round_rate. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: core: copy parent_names & return error codesMike Turquette
This patch cleans up clk_register and solves a few bugs by teaching clk_register and __clk_init to return error codes (instead of just NULL) to better align with the existing clk.h api. Along with that change this patch also introduces a new behavior whereby clk_register copies the parent_names array, thus allowing platforms to declare their parent_names arrays as __initdata. Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: Constify parent name arraysMark Brown
Drivers should be able to declare their arrays of parent names as const so the APIs need to accept const arguments. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> [mturquette@linaro.org: constified gate] Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: Make clk_get_rate() return 0 on errorRajendra Nayak
Most users of clk_get_rate() actually assume a non zero return value as a valid rate returned. Returing -EINVAL might confuse such users, so make it instead return zero on error. Besides the return value of clk_get_rate seems to be 'unsigned long'. Signed-off-by: Rajendra nayak <rnayak@ti.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: core: enforce clk_ops consistencyMike Turquette
Documentation/clk.txt has some handsome ASCII art outlining which clk_ops are mandatory for a given clock, given the capability of the hardware. Enforce those mandates with sanity checks in __clk_init. Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: core: clk_calc_new_rates handles NULL parentsMike Turquette
It is possible to call clk_set_rate on a clock with a NULL parent. One such example is an adjustable-rate root clock. Ensure that clk_calc_new_rates does not dereference parent without checking first and also handle the corner cases gracefully. Reported-by: Rajendra Nayak <rnayak@ti.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: core: remove dead code pathsMike Turquette
Some static inline dummy functions were left over from before the clock core was consolidated from several C files down to one. Remove them. Reported-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-04-24clk: core: correct clk_set_rate kerneldocMike Turquette
Remove old and misleading documentation from the previous clk_set_rate implementaion. Reported-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2012-03-16clk: introduce the common clock frameworkMike Turquette
The common clock framework defines a common struct clk useful across most platforms as well as an implementation of the clk api that drivers can use safely for managing clocks. The net result is consolidation of many different struct clk definitions and platform-specific clock framework implementations. This patch introduces the common struct clk, struct clk_ops and an implementation of the well-known clock api in include/clk/clk.h. Platforms may define their own hardware-specific clock structure and their own clock operation callbacks, so long as it wraps an instance of struct clk_hw. See Documentation/clk.txt for more details. This patch is based on the work of Jeremy Kerr, which in turn was based on the work of Ben Herrenschmidt. Signed-off-by: Mike Turquette <mturquette@linaro.org> Signed-off-by: Mike Turquette <mturquette@ti.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Rob Herring <rob.herring <at> calxeda.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Jeremy Kerr <jeremy.kerr@canonical.com> Cc: Arnd Bergman <arnd.bergmann@linaro.org> Cc: Paul Walmsley <paul@pwsan.com> Cc: Shawn Guo <shawn.guo@freescale.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Richard Zhao <richard.zhao@linaro.org> Cc: Saravana Kannan <skannan@codeaurora.org> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Linus Walleij <linus.walleij@stericsson.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Cc: Deepak Saxena <dsaxena@linaro.org> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Arnd Bergmann <arnd@arndb.de>