This is primarily useful when there's a driver that doesn't claim clocks
properly, but the bootloader leaves them on. It's not expected to be used
in normal cases, but for bringup and debug it's very useful to have the
option to not gate unclaimed clocks that are still on.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up trivial merge issue]
Factor out the SP810 clocking code into a separate driver,
selecting better (faster) parent at clk_prepare() time.
This is to avoid problems with clocking infrastructure
initialisation order, in particular to avoid dependency
of fixed clock being initialized before SP810. It also
makes vexpress platform OF-based clock initialisation code
unnecessary.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: add .unprepare, FIXME comment, cleaned up code]
Calling clk-si5351 driver non-OF ready was too early. This patch
makes clk-si5351 depend on CONFIG_OF again, until things get sorted out.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed spelling of Stephen's name]
The common clock api provides some helpers for clk-providers but does
not export these helpers. This hinders clk-providers to be built as modules.
This patch adds __clk_get_flags() to the list of exported symbols.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The case of PLL_TYPE_WM8750 in both these functions is missing a break
statement causing a fall-through to the default: case.
Insert the missing break statements.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This commit uses the new fixed-rate support on the composite clock to
unify osc24M_fixed and osc24M clocks, so it matches the actual hardware.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: replace clk_register_gatable_osc with a call to
clk_register_composite]
The composite clock assumes that any clock implementing the .recalc_rate
callback will also implement .round_rate and .set_rate. This is not
always true; the basic fixed-rate clock will only implement .recalc_rate
and a fixed-divider clock may choose to implement .recalc_rate and
.round_rate but not .set_rate.
Fix this by conditionally registering .round_rate and .set_rate
callbacks based on the rate_ops passed in to clk_composite_register.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Prashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: Emilio López <emilio@elopez.com.ar>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Rename all div_hw and div_ops related variables and functions to use
rate_hw, rate_ops, etc. This is to make the rate-change portion of the
composite clk implementation more generic. A patch following this one
will allow for fixed-rate clocks to reuse this infrastructure.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Reviewed-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: Emilio López <emilio@elopez.com.ar>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
This patch adds a common clock driver for Silicon Labs Si5351a/b/c
i2c programmable clock generators. Currently, the driver does not
support VXCO feature of si5351b. Passing platform_data or DT bindings
selectively allows to overwrite stored Si5351 configuration which is
very helpful for clock generators with empty eeprom configuration.
Corresponding device tree binding documentation is also added.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Michal Bachraty <michal.bachraty@streamunlimited.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Notifiers may return NOTIFY_(OK|DONE|STOP|BAD). The CCF uses an
inconsistent mix of checking against NOTIFY_STOP or NOTIFY_BAD.
This inconsistency leaves errors undetected in some cases:
clk_set_parent() calls __clk_speculate_rates(), which stops when it
hits a NOTIFIER_BAD (STOP is ignored), and passes this value back to the
caller.
clk_set_parent() compares this return value against NOTIFY_STOP only,
ignoring NOTIFY_BAD returns.
Use NOTIFY_STOP_MASK to detect a negative notifier return value and
document all four return value options.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The patch setups the first version of the clock tree for ab850x, which
is used by u8500 platforms. Mainly sysctrl clocks are used.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The abx500 sysctrl clocks are using the ab8500 sysctrl driver to
modify the clock hardware. Sysctrl clocks are represented by a
ab8500 sysctrl register and with a corresponding bitmask.
The sysctrl clocks are slow path clocks, which means clk_prepare
and clk_unprepare will be used to gate|ungate these clocks.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
cpu_freq_select is used as array subscript, thus the valid value range
is 0 ... ARRAY_SIZE() - 1.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up trivial merge issues]
Updating the clock tree topology must be protected with the spinlock
when doing clk_set_parent, otherwise we can not handle the migration
of the enable_count in a safe manner.
While issuing the .set_parent callback to make the clk-hw perform the
switch to the new parent, we can not hold the spinlock since it is must
be allowed to be slow path. This complicates error handling, but is still
possible to achieve.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Fixup the broken feature of allowing reparent of a clk to the
orhpan list and vice verse. When operating on a single-parent
clk, the .set_parent callback for the clk hw is optional to
implement, but for a multi-parent clk it is mandatory.
Moreover improve the errorhandling by verifying the prerequisites
before triggering clk notifiers. This will prevent unnecessary
rollback with ABORT_RATE_CHANGE.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Split __clk_reparent into three pieces, one for doing the actual
reparent for updating the clock tree topology, one for the
COMMON_CLK_DEBUG code and one for doing the rate recalculation.
This patch also makes it possible to hold the spinlock over the
update of the clock tree topology, which could not be done before
when both debugfs updates and clock rate updates was done within
the same function.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This flag was in place to prevent important clocks from getting gated
while they had no users. Now that the UART driver supports clocks
properly, we can drop this.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Dividers which have CLK_DIVIDER_ONE_BASED set have a redundant state,
being a divider value of zero. Some hardware implementations allow a
zero divider which simply doesn't alter the frequency. I.e. it acts like
a divide by one or bypassing the divider.
This flag is used to handle such HW in the clk-divider model.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The use common of_clk_init() function simplifies the clock initialization
and adds handling of the DT "fixed-clock".
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed $SUBJECT to reflect correct file path]
The kerneldoc comment for struct clk_mux documented the non-existent
num_clks instead of flags. Correct this.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Reentrancy into the clock framework is necessary for clock operations
that result in nested calls to the clk api. A common example is a clock
that is prepared via an i2c transaction, such as a clock inside of a
discrete audio chip or a power management IC. The i2c subsystem itself
will use the clk api resulting in a deadlock:
clk_prepare(audio_clk)
i2c_transfer(..)
clk_prepare(i2c_controller_clk)
The ability to reenter the clock framework prevents this deadlock.
Other use cases exist such as allowing .set_rate callbacks to call
clk_set_parent to achieve the best rate, or to save power in certain
configurations. Yet another example is performing pinctrl operations
from a clk_ops callback. Calls into the pinctrl subsystem may call
clk_{un}prepare on an unrelated clock. Allowing for nested calls to
reenter the clock framework enables both of these use cases.
Reentrancy is implemented by two global pointers that track the owner
currently holding a global lock. One pointer tracks the owner during
sleepable, mutex-protected operations and the other one tracks the owner
during non-interruptible, spinlock-protected operations.
When the clk framework is entered we try to hold the global lock. If it
is held we compare the current task against the current owner; a match
implies a nested call and we reenter. If the values do not match then
we block on the lock until it is released.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Olof Johansson
Mike Turquette
Pawel Moll
Sebastian Hesselbarth
Tony Prisk
Emilio López
Gregory CLEMENT
Soren Brinkmann
Ulf Hansson
Axel Lin
Jean-Francois Moine
James Hogan