clk: vexpress-osc: Support building as a module

Enable building the vexpress-osc clock driver as a module.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: linux-clk@vger.kernel.org
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

clk: vexpress-osc: Use the devres clock API variants

In preparation to enable the vexpress-osc clock driver as a module,
convert the driver to use the managed devres clock API variants. With
this, a driver .remove() hook is not needed.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-clk@vger.kernel.org
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

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 version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clk: versatile: Remove WARNs in ->round_rate()

clk_round_rate() is intended to be used to round a given clock rate to
the closest one achievable by the actual clock. This implies that the
input to clk_round_rate() is expected to be unachievable - and such
cases shouldn't be treated as exceptional.

To reflect this, remove the WARN_ONs which trigger when an unachievable
clock rate is passed to vexpress_osc_round_rate().

Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Brian Starkey <brian.starkey@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: versatile: add min/max rate boundaries for vexpress osc clock

Clock framework has a provider API(clk_hw_set_rate_range) to set the
min/max rate of a clock. Use the same to set the boundaries for the
vexpress osc clock.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-clk@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: versatile: make clk_ops const

Make this const as it is only stored in the const field of a
clk_init_data structure.

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

clk: versatile: Remove CLK_IS_ROOT

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

Cc: Pawel Moll <pawel.moll@arm.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: constify of_device_id array

of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)

__initdata updated to __initconst for
static const struct of_device_id ti_clkdm_match_table[]

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

ARM: vexpress: Remove non-DT code

Now, with the CLCD DT support available, there is no
more reason to keep the non-DT support for V2P-CA9.

Removed, together with "some" supporting code. It was
necessary to make PLAT_VERSATILE_SCHED_CLOCK optional
and selected by the machines still interested in it.

Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

mfd: vexpress: Convert custom func API to regmap

Components of the Versatile Express platform (configuration
microcontrollers on motherboard and daughterboards in particular)
talk to each other over a custom configuration bus. They
provide miscellaneous functions (from clock generator control
to energy sensors) which are represented as platform devices
(and Device Tree nodes). The transactions on the bus can
be generated by different "bridges" in the system, some
of which are universal for the whole platform (for the price
of high transfer latencies), others restricted to a subsystem
(but much faster).

Until now drivers for such functions were using custom "func"
API, which is being replaced in this patch by regmap calls.
This required:

* a rework (and move to drivers/bus directory, as suggested
by Samuel and Arnd) of the config bus core, which is much
simpler now and uses device model infrastructure (class)
to keep track of the bridges; non-DT case (soon to be
retired anyway) is simply covered by a special device
registration function

* the new config-bus driver also takes over device population,
so there is no need for special matching table for
of_platform_populate nor "simple-bus" hack in the arm64
model dtsi file (relevant bindings documentation has
been updated); this allows all the vexpress devices
fit into normal device model, making it possible
to remove plenty of early inits and other hacks in
the near future

* adaptation of the syscfg bridge implementation in the
sysreg driver, again making it much simpler; there is
a special case of the "energy" function spanning two
registers, where they should be both defined in the tree
now, but backward compatibility is maintained in the code

* modification of the relevant drivers:

* hwmon - just a straight-forward API change
* power/reset driver - API change
* regulator - API change plus error handling
simplification
* osc clock driver - this one required larger rework
in order to turn in into a standard platform driver

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mike Turquette <mturquette@linaro.org>

vexpress: Initialise the sysregs before setting up the clocks

Following arm64 commit bc3ee18a7a57 (arm64: init: Move of_clk_init to
time_init()), vexpress_osc_of_setup() is called via of_clk_init() long
before initcalls are issued. Initialising the vexpress oscillators
requires the vespress sysregs to be already initialised, so this patch
adds an explicit call to vexpress_sysreg_of_early_init() in vexpress
oscillator setup function.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Cc: Mike Turquette <mturquette@linaro.org>

clk: vexpress: NULL dereference on error path

If the allocation fails then we dereference the NULL in the error path.
Just return directly.

Fixes: ed27ff1db869 ('clk: Versatile Express clock generators ("osc") driver')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>

clk: vexpress: Use full node name to identify individual clocks

Previously all the clocks were reported as "osc". Now it will be
something like "/dcc/osc@0".

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: vexpress: Use common of_clk_init() function

Use common of_clk_init() function for clock initialization.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: Versatile Express clock generators ("osc") driver

This driver provides a common clock framework hardware driver
for Versatile Express clock generators (a.k.a "osc") controlled
via the config bus.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>