Fix overflows seen when writing into fan speed limit attributes.
Also fix crash due to division by zero, seen when certain very
large values (such as 2147483648, or 0x80000000) are written
into fan speed limit attributes.

Fixes: 594fbe71 ("Add support for GMT G762/G763 PWM fan controllers")
Cc: Arnaud Ebalard <arno@natisbad.org>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

i2c_driver does not need to set an owner because i2c_register_driver()
will set it.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

The I2C core always reports the MODALIAS uevent as "i2c:<client name"
regardless if the driver was matched using the I2C id_table or the
of_match_table. So technically there's no need for a driver to export
the OF table since currently it's not used.

In fact, the I2C device ID table is mandatory for I2C drivers since
a i2c_device_id is passed to the driver's probe function even if the
I2C core used the OF table to match the driver.

And since the I2C core uses different tables, OF-only drivers needs to
have duplicated data that has to be kept in sync and also the dev node
compatible manufacturer prefix is stripped when reporting the MODALIAS.

To avoid the above, the I2C core behavior may be changed in the future
to not require an I2C device table for OF-only drivers and report the
OF module alias. So, it's better to also export the OF table to prevent
breaking module autoloading if that happens.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

g762_remove() needs to first call hwmon_device_unregister() and then
g762_of_clock_disable(). For that reason, it is not possible to
convert it to devm_hwmon_device_register_with_groups() and the
the non device managed version must be used.

This is correctly stated in commit message for 398e16db ("hwmon:
(g762) Convert to hwmon_device_register_with_groups") but the
associated changes do in fact introduce a call to the device managed
version of the function.

This patch fixes that typo by switching to the non devm_ version.

Fixes: 398e16db ("hwmon: (g762) Convert to hwmon_device_register_with_groups")
Cc: stable@vger.kernel.org (3.17+)
Signed-off-by: NArnaud Ebalard <arno@natisbad.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Simplify the code a bit and also improve readability.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Use ATTRIBUTE_GROUPS macro and hwmon_device_register_with_groups() to simplify
the code a bit.

Use hwmon_device_register_with_groups rather than the device managed version to
ensure g762_of_clock_disable() is called after hwmon_device_unregister().
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Make of_device_id array const, because all OF functions
handle it as const.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

GMT G762/763 fan speed PWM controller is connected directly to a fan
and performs closed-loop or open-loop control of the fan speed. Two
modes - PWM or DC - are supported by the chip. Introduced driver
provides various knobs to control the operations of the chip (via
sysfs interface). Specific characteristics of the system can be passed
either using board init code or via DT. Documentation for both the
driver and DT bindings are also provided.
Signed-off-by: NArnaud Ebalard <arno@natisbad.org>
Tested-by: NSimon Guinot <simon.guinot@sequanux.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>