thermal: Add a thermal zone id accessor

In order to get the thermal zone id but without directly accessing the
thermal zone device structure, add an accessor.

Use the accessor in the hwmon_scmi and acpi_thermal.

No functional change intented.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal/core: Use the thermal zone 'devdata' accessor in hwmon located drivers

The thermal zone device structure is exposed to the different drivers
and obviously they access the internals while that should be
restricted to the core thermal code.

In order to self-encapsulate the thermal core code, we need to prevent
the drivers accessing directly the thermal zone structure and provide
accessor functions to deal with.

Use the devdata accessor introduced in the previous patch.

No functional changes intended.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net> #hwmon
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

hwmon: (scmi) Register explicitly with Thermal Framework

Available sensors are enumerated and reported by the SCMI platform server
using a 16bit identification number; not all such sensors are of a type
supported by hwmon subsystem and, among the supported ones, only a subset
could be temperature sensors that have to be registered with the Thermal
Framework.
Potential clashes between hwmon channels indexes and the underlying real
sensors IDs do not play well with the hwmon<-->thermal bridge automatic
registration routines and could need a sensible number of fake dummy
sensors to be made up in order to keep indexes and IDs in sync.

Avoid to use the hwmon<-->thermal bridge dropping the HWMON_C_REGISTER_TZ
attribute and instead explicit register temperature sensors directly with
the Thermal Framework.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20221031114018.59048-1-cristian.marussi@arm.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (scmi) port driver to the new scmi_sensor_proto_ops interface

Port the scmi hwmon driver to the new SCMI sensor interface based on
protocol handles and common devm_get_ops().

Link: https://lore.kernel.org/r/20210316124903.35011-25-cristian.marussi@arm.com
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

hwmon: (scmi) Update hwmon internal scale data type

Use an int to calculate scale values inside scmi_hwmon_scale() to match
the updated scale data type in struct scmi_sensor_info.

Link: https://lore.kernel.org/r/20201119174906.43862-4-cristian.marussi@arm.com
Cc: linux-hwmon@vger.kernel.org
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

hwmon: (scmi-hwmon) Avoid comma separated statements

Use semicolons and braces.

Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/5e1ca60df261e3bfd0e6510e388581a1d1f52c77.1598331149.git.joe@perches.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (scmi) Fix potential buffer overflow in scmi_hwmon_probe()

SMATCH detected a potential buffer overflow in the manipulation of
hwmon_attributes array inside the scmi_hwmon_probe function:

drivers/hwmon/scmi-hwmon.c:226
scmi_hwmon_probe() error: buffer overflow 'hwmon_attributes' 6 <= 9

Fix it by statically declaring the size of the array as the maximum
possible as defined by hwmon_max define.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20200715121338.GA18761@e119603-lin.cambridge.arm.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (scmi-hwmon) Match scmi device by both name and protocol id

The scmi bus now has support to match the driver with devices not only
based on their protocol id but also based on their device name if one is
available. This was added to cater the need to support multiple devices
and drivers for the same protocol.

Let us add the name "hwmon" to scmi_device_id table in the driver so
that in matches only with device with the same name and protocol id
SCMI_PROTOCOL_SENSOR. This is just for sake of completion and must
not be used to add IIO support in parallel. Instead, if IIO support is
added ever in future, we need to drop this hwmon driver entirely and
use the iio->hwmon bridge to access the sensors as hwmon devices if
needed.

Cc: linux-hwmon@vger.kernel.org
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scmi: Drop async flag in sensor_ops->reading_get

SENSOR_DESCRIPTION_GET provides attributes to indicate if the sensor
supports asynchronous read. Ideally we should be able to read that flag
and use asynchronous reads for any sensors with that attribute set.

In order to add that support, let's drop the async flag passed to
sensor_ops->reading_get and dynamically switch between sync and async
flags based on the attributes as provided by the firmware.

Cc: linux-hwmon@vger.kernel.org
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

hwmon: scmi: Scale values to target desired HWMON units

If the SCMI firmware implementation is reporting values in a scale that
is different from the HWMON units, we need to scale up or down the value
according to how far apart they are.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
[sudeep.holla: added check of scale = 0 for early exit in scmi_hwmon_scale]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

hwmon: (scmi-hwmon) Replace S_<PERMS> with octal values

Replace S_<PERMS> with octal values.

The conversion was done automatically with coccinelle. The semantic patches
and the scripts used to generate this commit log are available at
https://github.com/groeck/coccinelle-patches/hwmon/.

This patch does not introduce functional changes. It was verified by
compiling the old and new files and comparing text and data sizes.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (scmi) Remove redundant pointer check

Clang warns when the address of a pointer is used in a boolean context
as it will always return true.

drivers/hwmon/scmi-hwmon.c:59:24: warning: address of array
'sensor->name' will always evaluate to 'true'
[-Wpointer-bool-conversion]
if (sensor && sensor->name)
~~ ~~~~~~~~^~~~
1 warning generated.

Remove the check as it isn't doing anything currently; if validation
of the contents of the data structure was intended by the original
author (since this line has been present from the first version of
this driver), it can be added in a follow-up patch.

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (scmi) handle absence of few types of sensors

Currently the loop checks for non-zero count of sensors for each type
of sensors which is completely wrong. It also results in aborting the
registration of sensors if one or more types of sensors are completely
not supported by the platform SCMI firmware.

This patch fixes the issue by continue to loop and skiping sensor types
that are not present.

Fixes: b23688aefb8b ("hwmon: add support for sensors exported via ARM SCMI")
Reported-by: Jim Quinlan <james.quinlan@broadcom.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (scmi) return -EINVAL when sensor information is unavailable

Passing NULL pointer to PTR_ERR will result in return value of 0
indicating success which is clearly not what it is intended here.

This patch returns -EINVAL instead when the sensor information is not
available.

Fixes: b23688aefb8b ("hwmon: add support for sensors exported via ARM SCMI")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

hwmon: add support for sensors exported via ARM SCMI

Create a driver to add support for SoC sensors exported by the System
Control Processor (SCP) via the System Control and Management Interface
(SCMI). The supported sensor types is one of voltage, temperature,
current, and power.

The sensor labels and values provided by the SCP are exported via the
hwmon sysfs interface.

Cc: linux-hwmon@vger.kernel.org
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>