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: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: adapted clk_has_parent to struct clk_core
                        applied OMAP3+ DPLL fix from Tero & Tony]

Some devices don't use mmio to interact with dividers. Split out the
logic from the register read/write parts so that we can reuse the
division logic elsewhere.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Tested-by: NKenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

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: NStephen Boyd <sboyd@codeaurora.org>
Tested-by: NKenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

The common clk_register_{divider,gate,mux} functions allocated memory
for internal data which wasn't freed anywhere. Drivers using these
helpers could only unregister clocks but the memory would still leak.

Add corresponding unregister functions which will release all resources.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

This is in preparation for clock providers to not have to deal with struct clk.
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

Instead of struct clk, as this should be only used by providers.
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

As it's only used internally, in drivers/clk/clk.c.
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

Commit 79c6ab50 (clk: divider: add CLK_DIVIDER_READ_ONLY flag) in
v3.16 introduced the CLK_DIVIDER_READ_ONLY flag which caused the
recalc_rate() and round_rate() clock callbacks to be omitted.

However using this flag has the unfortunate side effect of causing the
clock recalculation code when a clock rate change is attempted to always
treat it as a pass-through clock, i.e. with a fixed divide of 1, which
may not be the case. Child clock rates are then recalculated using the
wrong parent rate.

Therefore instead of dropping the recalc_rate() and round_rate()
callbacks, alter clk_divider_bestdiv() to always report the current
divider as the best divider so that it is never altered.

For me the read only clock was the system clock, which divided the PLL
rate by 2, from which both the UART and the SPI clocks were divided.
Initial setting of the UART rate set it correctly, but when the SPI
clock was set, the other child clocks were miscalculated. The UART clock
was recalculated using the PLL rate as the parent rate, resulting in a
UART new_rate of double what it should be, and a UART which spewed forth
garbage when the rate changes were propagated.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Max Schwarz <max.schwarz@online.de>
Cc: <stable@vger.kernel.org> # v3.16+
Acked-by: NHaojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: NMichael Turquette <mturquette@linaro.org>

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: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NHans de Goede <hdegoede@redhat.com>

CLK_OF_DECLARE relies on OF_DECLARE_1 that is defined in of.h. Fixes build
errors when one use CLK_OF_DECLARE but doesn't include of.h
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NHans de Goede <hdegoede@redhat.com>

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: NMike Turquette <mturquette@linaro.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NHans de Goede <hdegoede@redhat.com>

The added gpio-gate-clock is a basic clock that can be enabled and
disabled trough a gpio output. The DT binding document for the clock
is also added. For EPROBE_DEFER handling the registering of the clock
has to be delayed until of_clk_get() call time.
Signed-off-by: NJyri Sarha <jsarha@ti.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

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: NPeter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

From: Heiko Stuebner <heiko@sntech.de>

Similar to muxes which already have a read-only flag there sometimes
exist dividers which should not be changed by the clock framework
but whose value still should be readable.

Therefore add a READ_ONLY flag similar to the mux-one to clk-divider
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
[changed flag bit to BIT(5) as suggested by Tomasz Figa]
Signed-off-by: NThomas Abraham <thomas.ab@samsung.com>
Acked-by: NTomasz Figa <t.figa@samsung.com>
Acked-by: NMax Schwarz <max.schwarz@online.de>
Tested-by: NMax Schwarz <max.schwarz@online.de>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

We now have several OF match tables using linker sections that are
nearly the same definition. The only variation is the callback function
prototype. Create a common define for creating linker section OF match
table entries which each table declaration can use.
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NRob Herring <robh@kernel.org>

Fractional divider clocks are fairly common. This adds basic
type for them.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: NMike Turquette <mturquette@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

General:
  - Add parameter names to .round_rate() and .set_rate().

Documentation/clk.txt:
  - Add missing parameter for .set_rate(),
  - Add missing .debug_init().

include/linux/clk-provider.h:
  - Add parent rate documentation for .round_rate(),
  - Reorder documentation to match implementation order,
  - Add missing documentation for .init().
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

- Remove spaces in front of TABs,
- Correct indentation for some CLK_* flag descriptions.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

In some cases, we want to be able to round the divider to the closest one,
instead than rounding up.

This patch adds a new CLK_DIVIDER_ROUND_CLOSEST flag to specify the divider
has to round to closest div, keeping rounding up as de default behaviour.
Signed-off-by: NMaxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Add a new clk_ops->debug_init method to allow a clock hardware
driver to populate the clock's debugfs directory with entries
beyond those common for every clock.
Signed-off-by: NAlex Elder <elder@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

ti_dt_clk_init_provider() can now be used to initialize the contents of
a single clock IP block. This parses all the clocks under the IP block
and calls the corresponding init function for them.

This patch also introduces a helper function for the TI clock drivers
to get register info from DT and append the master IP info to this.
Signed-off-by: NTero Kristo <t-kristo@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Some of Qualcomm's clocks can change their parent and rate at the
same time with a single register write. Add support for this
hardware to the common clock framework by adding a new
set_rate_and_parent() op. When the clock framework determines
that both the parent and the rate are going to change during
clk_set_rate() it will call the .set_rate_and_parent() op if
available and fall back to calling .set_parent() followed by
.set_rate() otherwise.
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

this change implements a clock driver for the MPC512x PowerPC platform
which follows the COMMON_CLK approach and uses common clock drivers
shared with other platforms

this driver implements the publicly announced set of clocks (those
listed in the dt-bindings header file), as well as generates additional
'struct clk' items where the SoC hardware cannot easily get mapped to
the common primitives (shared code) of the clock API, or requires
"intermediate clock nodes" to represent clocks that have both gates and
dividers

the previous PPC_CLOCK implementation is kept in place and remains
active for the moment, the newly introduced CCF clock driver will
receive additional support for backwards compatibility in a subsequent
patch before it gets enabled and will replace the PPC_CLOCK approach

some of the clock items get pre-enabled in the clock driver to not have
them automatically disabled by the underlying clock subsystem because of
their being unused -- this approach is desirable because
- some of the clocks are useful to have for diagnostics and information
  despite their not getting claimed by any drivers (CPU, internal and
  external RAM, internal busses, boot media)
- some of the clocks aren't claimed by their peripheral drivers yet,
  either because of missing driver support or because device tree specs
  aren't available yet (but the workarounds will get removed as the
  drivers get adjusted and the device tree provides the clock specs)

clkdev registration provides "alias names" for few clock items
- to not break those peripheral drivers which encode their component
  index into the name that is used for clock lookup (UART, SPI, USB)
- to not break those drivers which use names for the clock lookup which
  were encoded in the previous PPC_CLOCK implementation (NFC, VIU, CAN)
this workaround will get removed as these drivers get adjusted after
device tree based clock lookup has become available

the COMMON_CLK implementation copes with device trees which lack an
oscillator node (backwards compat), the REF clock is then derived from
the IPS bus frequency and multiplier values fetched from hardware

Cc: Mike Turquette <mturquette@linaro.org>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NGerhard Sittig <gsi@denx.de>
Signed-off-by: NAnatolij Gustschin <agust@denx.de>

This patch adds support for accuracy retrieval on fixed clocks.
It also adds a new dt property called 'clock-accuracy' to define the clock
accuracy.

This can be usefull for oscillator (RC, crystal, ...) definitions which are
always given an accuracy characteristic.
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

The clock accuracy is expressed in ppb (parts per billion) and represents
the possible clock drift.
Say you have a clock (e.g. an oscillator) which provides a fixed clock of
20MHz with an accuracy of +- 20Hz. This accuracy expressed in ppb is
20Hz/20MHz = 1000 ppb (or 1 ppm).

Clock users may need the clock accuracy information in order to choose
the best clock (the one with the best accuracy) across several available
clocks.

This patch adds clk accuracy retrieval support for common clk framework by
means of a new function called clk_get_accuracy.
This function returns the given clock accuracy expressed in ppb.

In order to get the clock accuracy, this implementation adds one callback
called recalc_accuracy to the clk_ops structure.
This callback is given the parent clock accuracy (if the clock is not a
root clock) and should recalculate the given clock accuracy.

This callback is optional and may be implemented if the clock is not
a perfect clock (accuracy != 0 ppb).
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Walks the "clocks" array of parent clock phandles and returns the
number.
Signed-off-by: NMike Turquette <mturquette@linaro.org>

the common clock drivers were motivated/initiated by ARM development
and apparently assume little endian peripherals

wrap register/peripherals access in the common code (div, gate, mux)
in preparation of adding COMMON_CLK support for other platforms
Signed-off-by: NGerhard Sittig <gsi@denx.de>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Implement clk-mux remuxing if the CLK_SET_RATE_NO_REPARENT flag isn't
set. This implements determine_rate for clk-mux to propagate to each
parent and to choose the best one (like clk-divider this chooses the
parent which provides the fastest rate <= the requested rate).

The determine_rate op is implemented as a core helper function so that
it can be easily used by more complex clocks which incorporate muxes.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Add a CLK_SET_RATE_NO_REPARENT clock flag, which will prevent muxes
being reparented during clk_set_rate.

To avoid breaking existing platforms, all callers of clk_register_mux()
are adjusted to pass the new flag. Platform maintainers are encouraged
to remove the flag if they wish to allow mux reparenting on set_rate.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Chao Xie <xiechao.mail@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Emilio López" <emilio@elopez.com.ar>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Prashant Gaikwad <pgaikwad@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrew Chew <achew@nvidia.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Thomas Abraham <thomas.abraham@linaro.org>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: spear-devel@list.st.com
Cc: linux-tegra@vger.kernel.org
Tested-by: NHaojian Zhuang <haojian.zhuang@gmail.com>
Acked-by: Stephen Warren <swarren@nvidia.com> [tegra]
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> [sunxi]
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com> [Zynq]
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Add core support to allow clock implementations to select the best
parent clock when rounding a rate, e.g. the one which can provide the
closest clock rate to that requested. This is by way of adding a new
clock op, determine_rate(), which is like round_rate() but has an extra
parameter to allow the clock implementation to optionally select a
different parent clock. The core then takes care of reparenting the
clock when setting the rate.

The parent change takes place with the help of some new private data
members. struct clk::new_parent specifies a clock's new parent (NULL
indicates no change), and struct clk::new_child specifies a clock's new
child (whose new_parent member points back to it). The purpose of these
are to allow correct walking of the future tree for notifications prior
to actually reparenting any clocks, specifically to skip child clocks
who are being reparented to another clock (they will be notified via the
new parent), and to include any new child clock. These pointers are set
by clk_calc_subtree(), and the new_child pointer gets cleared when a
child is actually reparented to avoid duplicate POST_RATE_CHANGE
notifications.

Each place where round_rate() is called, determine_rate() is checked
first and called in preference. This restructures a few of the call
sites to simplify the logic into if/else blocks.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Abstract access to the clock parent cache by defining
clk_get_parent_by_index(clk, index). This allows access to parent
clocks from clock drivers.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Some platforms have read-only clock muxes that are preconfigured at
reset and cannot be changed at runtime. This patch extends mux clock
driver to allow handling such read-only muxes by adding new
CLK_MUX_READ_ONLY mux flag.
Signed-off-by: NTomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

In Rockchip Cortex-A9 based chips, they don't use paradigm of
reading-changing-writing the register contents.  Instead they
use a hiword mask to indicate the changed bits.

When b1 should be set as gate, it also needs to indicate the change
by setting hiword mask (b1 << 16).

The patch adds gate flag for this usage.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NHaojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

In both Hisilicon & Rockchip Cortex-A9 based chips, they don't use the
paradigm of reading-changing-writing the register contents.
Instead they use a hiword mask to indicate the changed bits.

When b01 should be set as setting divider, it also needs to indicate
the change by setting hiword mask (b11 << 16).

The patch adds divider flag for this usage.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NHaojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

In both Hisilicon & Rockchip Cortex-A9 based chips, they don't use the
paradigm of reading-changing-writing the register contents.
Instead they use a hiword mask to indicate the changed bits.

When b01 should be set as switching mux, it also needs to indicate
the change by setting hiword mask (b11 << 16).

The patch adds mux flag for this usage.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NHaojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Some drivers that are shared between architectures have HAVE_CLK selected
but don't have OF. To remove compilation errors for drivers that provide
clocks on DT with of_clk_add_provider we would have to enclose these calls
within #ifdef CONFIG_OF, #endif.

This patch adds some stubs for OF related clk-provider functions that
either do nothing or return appropriate values if CONFIG_OF is not set.
So, definition of these routines will always be available.
Signed-off-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

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: NMike Turquette <mturquette@linaro.org>
Reviewed-by: NPrashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: NEmilio López <emilio@elopez.com.ar>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>

Add support for DT "fixed-factor-clock" binding to the common fixed
factor clock support.
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: NChristian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: NMike 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: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>