hwmon: (max20730) fix Wvoid-pointer-to-enum-cast warning

'chip_id' is an enum, thus cast of pointer on 64-bit compile test with W=1
causes:

max20730.c:719:13: error: cast to smaller integer type 'enum chips' from 'const void *' [-Werror,-Wvoid-pointer-to-enum-cast]

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230810093157.94244-9-krzysztof.kozlowski@linaro.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus/max20730) Remove strlcpy occurences

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with direct assignment.

strlcpy in this file is used to copy fixed-length strings which can be
completely avoided by direct assignment and is safe to do so. strlen()
is used to return the length of @tbuf.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230712214307.2424810-1-azeemshaikh38@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230714174607.4057185-1-robh@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230505131718.1210071-1-u.kleine-koenig@pengutronix.de
[groeck: Added missing change in pmbus/acbel-fsg032.c]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus) Introduce PMBUS symbol namespace

Exported pmbus symbols are only supposed to be used from PMBus code.
Introduce PMBUS symbol namespace to prevent misuse from other code.

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

hwmon: (pmbus) shrink code and remove pmbus_do_remove()

The only action currently performed in pmbus_do_remove() is removing the
debugfs hierarchy. We can schedule a devm action at probe time and remove
pmbus_do_remove() entirely from all pmbus drivers.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20201026105352.20359-1-brgl@bgdev.pl
[groeck: Removed references to pmbus_do_remove from documentation]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus/max20730) delete some dead code

The debugfs_create_dir() function never returns NULL. Normal users are
not supposed to check the return value so the correct fix is just to
delete this check.

In the case where the debugfs_create_dir() fails, the function returns
NULL. The other debugfs function check for NULL directory and handle
it.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20201022070659.GA2817762@mwanda
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus/max20730) use scnprintf() instead of snprintf()

The snprintf() function returns the number of characters which would
have been printed if there were enough space, but the scnprintf()
returns the number of characters which were actually printed. If the
buffer is not large enough, then using snprintf() would result in a
read overflow and an information leak.

Fixes: 8910c0bd533d ("hwmon: (pmbus/max20730) add device monitoring via debugfs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20201022070824.GC2817762@mwanda
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus/max20730) adjust the vout reading given voltage divider

Problem:
We use voltage dividers so that the voltage presented at the voltage
sense pins is confusing. We might need to convert these readings to more
meaningful readings given the voltage divider.

Solution:
Read the voltage divider resistance from dts and convert the voltage
reading to a more meaningful reading.

Testing:
max20730 with voltage divider

Signed-off-by: Chu Lin <linchuyuan@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201004031445.2321090-3-linchuyuan@google.com
[groeck: Return -EINVAL instead of -ENODEV on bad deevicetree data]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus/max20730) add device monitoring via debugfs

Add debugfs interface support for accessing device specific registers
(MFR_VOUT_MIN, MFR_DEVSET1 and MFR_DEVSET2) and others including
OPERATION, ON_OFF_CONFIG, SMB_ALERT_MASK, VOUT_MODE, VOUT_COMMAND
and VOUT_MAX.

Signed-off-by: Ugur Usug <ugur.usug@maximintegrated.com>
Link: https://lore.kernel.org/r/MWHPR11MB1965C01083AD013C630646B2FD3B0@MWHPR11MB1965.namprd11.prod.outlook.com
[groeck: Resolved conflics seen due to PMBus driver API changes]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon (pmbus) use simple i2c probe function

pmbus_do_probe doesn't use the id information provided in its second
argument, so this can be removed, which then allows using the
single-parameter i2c probe function ("probe_new") for probes.

This avoids scanning the identifier tables during probes.

Drivers which didn't use the id are converted as-is; drivers which did
are modified as follows:

* if the information in i2c_client is sufficient, that's used instead
(client->name);
* configured v. probed comparisons are performed by comparing the
configured name to the detected name, instead of the ids; this
involves strcmp but is still cheaper than comparing all the device
names when scanning the tables;
* anything else is handled by calling i2c_match_id() with the same
level of error-handling (if any) as before.

Additionally, the mismatch message in the ltc2978 driver is adjusted
so that it no longer assumes that the driver_data is an index into
ltc2978_id.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Acked-by: Wolfram Sang <wsa@kernel.org>
Link: https://lore.kernel.org/r/20200808210004.30880-1-steve@sk2.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus/max20730) Add max20710 support

Add support for max20710 into the existing max20730 driver.

Signed-off-by: Ugur Usug <ugur.usug@maximintegrated.com>
Link: https://lore.kernel.org/r/BYAPR11MB317423C13909AE6F1913BBD7FD9C0@BYAPR11MB3174.namprd11.prod.outlook.com
[groeck: Fixed various whitespace errors]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus) Add 'phase' parameter where needed for multi-phase support

In preparation for multi-phase support, add 'phase' parameter to read_word
and set_page functions. Actual multi-phase support will be added in
a subsequent patch.

Cc: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (pmbus) Driver for MAX20730, MAX20734, and MAX20743

Add support for Maxim MAX20730, MAX20734, MAX20743 Integrated,
Step-Down Switching Regulators with PMBus support.

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