clk: wm831x: clkout: Add a determine_rate hook

The WM381x "clkout" clock implements a mux with a set_parent hook,
but doesn't provide a determine_rate implementation.

This is a bit odd, since set_parent() is there to, as its name implies,
change the parent of a clock. However, the most likely candidates to
trigger that parent change are either the assigned-clock-parents device
tree property or a call to clk_set_rate(), with determine_rate()
figuring out which parent is the best suited for a given rate.

The other trigger would be a call to clk_set_parent(), but it's far less
used, and it doesn't look like there's any obvious user for that clock.

Similarly, it doesn't look like the device tree using that clock driver
uses any of the assigned-clock properties on that clock.

So, the set_parent hook is effectively unused, possibly because of an
oversight. However, it could also be an explicit decision by the
original author to avoid any reparenting but through an explicit call to
clk_set_parent().

The latter case would be equivalent to setting the determine_rate
implementation to clk_hw_determine_rate_no_reparent(). Indeed, if no
determine_rate implementation is provided, clk_round_rate() (through
clk_core_round_rate_nolock()) will call itself on the parent if
CLK_SET_RATE_PARENT is set, and will not change the clock rate
otherwise.

And if it was an oversight, then we are at least explicit about our
behavior now and it can be further refined down the line.

Cc: patches@opensource.cirrus.com
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221018-clk-range-checks-fixes-v4-23-971d5077e7d2@cerno.tech
| Reported-by: kernel test robot <lkp@intel.com>:
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clk: make clk_init_data const

Make these const as they are only stored in the init field of a clk_hw
structure, which is const.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: wm831x: fix usleep_range with bad range

The delay here is not in atomic context and does not seem critical with
respect to precision, but usleep_range(min,max) with min==max results in
giving the timer subsystem no room to optimize uncritical delays. Fix
this by setting the range to 2000,3000 us.

Fixes: commit f05259a6ffa4 ("clk: wm831x: Add initial WM831x clock driver")
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: clk-wm831x: fix a logic error

Fix bug https://bugzilla.kernel.org/show_bug.cgi?id=188561. Function
wm831x_clkout_is_prepared() returns "true" when it fails to read
CLOCK_CONTROL_1. "true" means the device is already prepared. So
return "true" on the read failure seems improper.

Signed-off-by: Pan Bian <bianpan2016@163.com>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Fixes: f05259a6ffa4 ("clk: wm831x: Add initial WM831x clock driver")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: wm831x: Migrate to clk_hw based registration APIs

Now that we have clk_hw based provider APIs to register clks, we
can get rid of struct clk pointers while registering clks in
these drivers, allowing us to move closer to a clear split of
consumer and provider clk APIs.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: wm831x: Remove CLK_IS_ROOT

This flag is a no-op now. Remove usage of the flag.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: wm831x: Remove clk.h include

Clock provider drivers generally shouldn't include clk.h because
it's the consumer API. Remove the include here because this is a
provider driver.

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: Remove .owner field for driver

There is no need to init .owner field.

Based on the patch from Peter Griffin <peter.griffin@linaro.org>
"mmc: remove .owner field for drivers using module_platform_driver"

This patch removes the superflous .owner field for drivers which
use the module_platform_driver API, as this is overriden in
platform_driver_register anyway."

Signed-off-by: Kiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: wm831x: get rid of the implementation of remove function

The remove function implemented for platform driver's remove callback
just return 0 as part of its implementation.

Remove this APIs and do not pass the valid .remove for platform driver.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: wm831x: Initialise wm831x pointer on init

Otherwise any attempt to interact with the hardware will crash. This is
what happens when drivers get written blind.

Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: wm831x: Provide is_prepared() rather than is_enabled()

Since the driver was written an is_prepared() operation has been made
possible. Since the driver uses I2C I/O only prepare operations are
provided so move the is_enabled() operation over to is_prepared().

Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: use platform_{get,set}_drvdata()

Use the wrapper functions for getting and setting the driver data using
platform_device instead of using dev_{get,set}_drvdata() with &pdev->dev,
so we can directly pass a struct platform_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: wm831x: Fix wm831x_clkout_get_parent

Current code looks strange because calling wm831x_clkout_set_parent() with 0 as
parent parameter, wm831x_clkout_get_parent() will return 1.

According to the datasheet:
R16528 (4090h) Clock Control1
BIT 0: CLKOUT output source select
0 = FLL output
1 = 32.768kHz oscillator

Thus fix the entry order in wm831x_clkout_parents[] to make it has
the same meaning as the datasheet and make the return value
of wm831x_clkout_get_parent() consistent with the parent pass to
wm831x_clkout_set_parent().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: wm831x: Fix update wrong register for enable/disable FLL

According to the datasheet, FLL Enable is controlled by
R16530 (4092h) FLL Control1
BIT 0: FLL Enable
0 = Disable
1 = Enable

Thus the code should update WM831X_FLL_CONTROL_1 register rather than
WM831X_FLL_CONTROL_2 register.

Also fixes a trivial typo in dev_crit message.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: remove use of __devexit

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clk: remove use of __devinit

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clk: remove use of __devexit_p

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Mike Turquette <mturquette@linaro.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clk: wm831x: Use devm_clk_register() to simplify code

Move this driver to use devm_clk_register() to simplify some
error paths and reduce lines of code.

Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: wm831x: Fix clk_register() error code checking

clk_register() returns an ERR_PTR upon failure, not NULL. Fix
these error paths.

Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: wm831x: Add initial WM831x clock driver

The WM831x and WM832x series of PMICs contain a flexible clocking
subsystem intended to provide always on and system core clocks. It
features:

- A 32.768kHz crystal oscillator which can optionally be used to pass
through an externally generated clock.
- A FLL which can be clocked from either the 32.768kHz oscillator or
the CLKIN pin.
- A CLKOUT pin which can bring out either the oscillator or the FLL
output.
- The 32.768kHz clock can also optionally be brought out on the GPIO
pins of the device.

This driver fully supports the 32.768kHz oscillator and CLKOUT. The FLL
is supported only in AUTO mode, the full flexibility of the FLL cannot
currently be used.

Due to a lack of access to systems where the core SoC has been converted
to use the generic clock API this driver has been compile tested only.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>