In order to aid debugging, we add a debugfs interface to the driver
that allows direct interaction with the AVS co-processor.

The debugfs interface provides a means for reading all and writing some
of the mailbox registers directly from the shell prompt and enables a
user to execute the communications protocol between ARM CPU and AVS CPU
step-by-step.

This interface should be used for debugging purposes only.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This driver supports voltage and frequency scaling on Broadcom STB SoCs
using AVS firmware with DFS and DVFS support.

Actual frequency or voltage scaling is done exclusively by the AVS
firmware. The driver merely provides a standard CPUfreq interface to
other kernel components and userland, and instructs the AVS firmware to
perform frequency or voltage changes on its behalf.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

After switching the core module clocks controlling the Integrator
clock frequencies to the common clock framework, defining the
operating points in the device tree, and activating the generic
DT-based CPUfreq driver, we can retire the old Integrator
cpufreq driver.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The MT8173 cpufreq driver can currently only be built-in, but
it has a Kconfig dependency on the thermal core. THERMAL
can be a loadable module, which in turn makes this driver
impossible to build.

It is nicer to make the cpufreq driver a module as well, so
this patch turns the option in to a 'tristate' and adapts
the dependency accordingly.

The driver has no module_exit() function, so it will continue
to not support unloading, but it can be built as a module
and loaded at runtime now.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 5269e7067cd6 (cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The bootloader is charged with the responsibility to provide platform
specific Dynamic Voltage and Frequency Scaling (DVFS) information via
Device Tree.  This driver takes the supplied configuration and
registers it with the new generic OPP framework, to then be used with
CPUFreq.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This driver is the only one that calls regulator_sync_voltage(), but it
can currently be built with CONFIG_REGULATOR disabled, producing
this build error:

drivers/cpufreq/tegra124-cpufreq.c: In function 'tegra124_cpu_switch_to_pllx':
drivers/cpufreq/tegra124-cpufreq.c:68:2: error: implicit declaration of function 'regulator_sync_voltage' [-Werror=implicit-function-declaration]
  regulator_sync_voltage(priv->vdd_cpu_reg);

My first attempt was to implement a helper for this function
for regulator_sync_voltage, but Mark Brown explained:

   We don't do this for *all* regulator API functions - there's some where
   using them strongly suggests that there is actually a dependency on
   the regulator API.  This does seem like it might be falling into the
   specialist category [...]
   Looking at the code I'm pretty unclear on what the authors think the
   use of _sync_voltage() is doing in the first place so it may be even
   better to just remove the call.  It seems to have been included in the
   first commit so there's not changelog explaining things and there's
   no comment either.  I'd *expect* it to be a noop as far as I can see.

This adds the dependency to make the driver always build successfully
or not be enabled at all. Alternatively, we could investigate if the
driver should stop calling regulator_sync_voltage instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Register passive cooling devices when initialising cpufreq on
big.LITTLE systems. If the device tree provides a dynamic power
coefficient for the CPUs then the bound cooling device will support
the extensions that allow it to be used with all the existing thermal
governors including the power allocator governor.

A cooling device will be created per individual frequency domain and
can be bound to thermal zones via the thermal DT bindings.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The SCPI clk driver registers the virtual cpufreq device that kicks off
initialisation of the SCPI cpufreq driver. Also, clk_get() will fail for
the cpufreq driver if the SCPI clk driver is missing.

Fix this by making the SCPI cpufreq driver explicitly depend on the SCPI
clk driver.

Fixes: 8def31034d03 (cpufreq: arm_big_little: add SCPI interface driver)
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>