clk: tegra: super: Switch to determine_rate

The Tegra super clocks 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 candidate to
trigger that parent change is 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.

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 driver does implement round_rate() though, which means that we can
change the rate of the clock, but we will never get to change the
parent.

However, It's hard to tell whether it's been done on purpose or not.

Since we'll start mandating a determine_rate() implementation, let's
convert the round_rate() implementation to a determine_rate(), which
will also make the current behavior explicit. And if it was an
oversight, the clock behaviour can be adjusted later on.

Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Prashant Gaikwad <pgaikwad@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221018-clk-range-checks-fixes-v4-65-971d5077e7d2@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: tegra: super: Add a determine_rate hook

The Tegra super mux 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.

However, the upstream device trees seem to use assigned-clock-parents on
that clock to force the parent at boot time, so it's likely that the
author intent was to force the parent through the device tree and
prevent any reparenting but through an explicit call to
clk_set_parent().

This 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.

Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Prashant Gaikwad <pgaikwad@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221018-clk-range-checks-fixes-v4-35-971d5077e7d2@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: tegra: Support runtime PM and power domain

The Clock-and-Reset controller resides in a core power domain on NVIDIA
Tegra SoCs. In order to support voltage scaling of the core power domain,
we hook up DVFS-capable clocks to the core GENPD for managing of the
GENPD's performance state based on the clock changes.

Some clocks don't have any specific physical hardware unit that backs
them, like root PLLs and system clock and they have theirs own voltage
requirements. This patch adds new clk-device driver that backs the clocks
and provides runtime PM functionality for them. A virtual clk-device is
created for each such DVFS-capable clock at the clock's registration time
by the new tegra_clk_register() helper. Driver changes clock's device
GENPD performance state based on clk-rate notifications.

In result we have this sequence of events:

1. Clock driver creates virtual device for selective clocks, enables
runtime PM for the created device and registers the clock.
2. Clk-device driver starts to listen to clock rate changes.
3. Something changes clk rate or enables/disables clk.
4. CCF core propagates the change through the clk tree.
5. Clk-device driver gets clock rate-change notification or GENPD core
handles prepare/unprepare of the clock.
6. Clk-device driver changes GENPD performance state on clock rate
change.
7. GENPD driver changes voltage regulator state change.
8. The regulator state is committed to hardware via I2C.

We rely on fact that DVFS is not needed for Tegra I2C and that Tegra I2C
driver already keeps clock always-prepared. Hence I2C subsystem stays
independent from the clk power management and there are no deadlock spots
in the sequence.

Currently all clocks are registered very early during kernel boot when the
device driver core isn't available yet. The clk-device can't be created
at that time. This patch splits the registration of the clocks in two
phases:

1. Register all essential clocks which don't use RPM and are needed
during early boot.

2. Register at a later boot time the rest of clocks.

This patch adds power management support for Tegra20 and Tegra30 clocks.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Tested-by: Paul Fertser <fercerpav@gmail.com> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

clk: tegra: clk-super: Add restore-context support

This patch implements restore_context for clk_super_mux and clk_super.

During system supend, core power goes off the and context of Tegra
CAR registers is lost.

So on system resume, context of super clock registers are restored
to have them in same state as before suspend.

Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

clk: tegra: clk-super: Fix to enable PLLP branches to CPU

This patch has a fix to enable PLLP branches to CPU before changing
the CPU cluster clock source to PLLP for Gen5 Super clock and
disables PLLP branches to CPU when not in use.

During system suspend entry and exit, CPU source will be switched
to PLLP and this needs PLLP branches to be enabled to CPU prior to
the switch.

On system resume, warmboot code enables PLLP branches to CPU and
powers up the CPU with PLLP clock source.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope 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 you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clk: tegra: Make tegra_clk_super_mux_ops static

Fix sparse warning:

drivers/clk/tegra/clk-super.c:124:22:
warning: symbol 'tegra_clk_super_mux_ops' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: tegra: Add super clock mux/divider

Add a super clock type which implements both mux and divider. This is
used for aclk.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Tested-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

clk: tegra: Properly include clk.h

Clock provider drivers generally shouldn't include clk.h because
it's the consumer API. Only include clk.h in files that are using
it. Also add in a clkdev.h include that was missing in a file
using clkdev APIs.

Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

clk: tegra: Implement locking for super clock

Although tegra_clk_register_super_mux() has a lock parameter, the lock is not
actually used by the code. Fixed with this patch.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Reviewed-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

clk: tegra: add Tegra specific clocks

Add Tegra specific clocks, pll, pll_out, peripheral, frac_divider, super.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
[swarren: alloc sizeof(*foo) not sizeof(struct foo), add comments re:
storing pointers to stack variables, make a timeout loop more idiomatic,
use _clk_pll_disable() not clk_disable_pll() from _program_pll() to
avoid redundant lock operations, unified tegra_clk_periph() and
tegra_clk_periph_nodiv(), unified tegra_clk_pll{,e}, rename all clock
registration functions so they don't have the same name as the clock
structs, return -EINVAL from clk_plle_enable when matching table rate
not found, pass ops to _tegra_clk_register_pll rather than a bool.]
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>