There is no need to actively disable a regulator that has not been
enabled by the driver, which makes the call to cc2_disable() in the
probe function meaningless, because the probe function never enables
the device's dedicated regulator.
Once the call to cc2_disable() is dropped, the error paths can directly
return dev_err_probe() in all cases.
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Message-ID: <20240813-chipcap2-probe-improvements-v2-1-e9a2932a8a00@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The return path can be improved by returning upon first failure. The
current implementation would try to register the second interrupt even
if the first one failed, which is unnecessary.
Moreover, if no irqs are available, the return value should be zero
(the driver supports the use case with no interrupts). Currently the
initial value is unassigned and that may lead to returning an unknown
value if stack variables are not automatically set to zero and no irqs
were provided.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-hwmon/294e4634-89d4-415e-a723-b208d8770d7c@gmail.com/T/#t
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20240207-chipcap2_init_vars-v1-2-08cafe43e20e@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The reg_val variable in cc2_get_reg_val() might be used without a known
value if cc2_read_reg() fails. That leads to a useless data conversion
because the returned error means the read operation failed and the data is
not relevant.
That makes its initial value irrelevant as well, so skip the data
conversion instead. If no error happens, a value is assigned to reg_val
and the data conversion is required.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-hwmon/294e4634-89d4-415e-a723-b208d8770d7c@gmail.com/T/#t
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20240207-chipcap2_init_vars-v1-1-08cafe43e20e@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The Amphenol ChipCap 2 is a capacitive polymer humidity and temperature
sensor with an integrated EEPROM and minimum/maximum humidity alarms.
All device variants offer an I2C interface and depending on the part
number, two different output modes:
- CC2D: digital output
- CC2A: analog (PDM) output
This driver adds support for the digital variant (CC2D part numbers),
which includes the following part numbers:
- non-sleep measurement mode (CC2D23, CC2D25, CC2D33, CC2D35)
- sleep measurement mode (CC2D23S, CC2D25S, CC2D33S, CC2D35S)
The Chipcap 2 EEPROM can be accessed to configure a series of parameters
like the minimum/maximum humidity alarm threshold and hysteresis. The
EEPROM is only accessible in the command window after a power-on reset.
The default window lasts 10 ms if no Start_CM command is sent. After the
command window is finished (either after the mentioned timeout of after
a Start_NOM command is sent), the device enters the normal operation
mode and makes a first measurement automatically.
Unfortunately, the device does not provide any hardware or software
reset and therefore the driver must trigger power cycles to enter the
command mode. A dedicated, external regulator is required for that.
This driver keeps the device off until a measurement or access to the
EEPROM is required, making use of the first automatic measurement to
avoid different code paths for sleep and non-sleep devices.
The minimum and maximum humidity alarms are configured with two
registers per alarm: one stores the alarm threshold and the other one
keeps the value that turns off the alarm. The alarm signals are only
updated when a measurement is carried out.
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20240130-topic-chipcap2-v6-5-260bea05cf9b@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
