For the sake of DT binding stability, this IIO driver is a child of an
MFD driver for Allwinner A10, A13 and A31 because there already exists a
DT binding for this IP. The MFD driver has a DT node but the IIO driver
does not.
The IIO device registers the temperature sensor in the thermal framework
using the DT node of the parent, the MFD device, so the thermal
framework could match the phandle to the MFD device in the DT and the
struct device used to register in the thermal framework.
devm_thermal_zone_of_sensor_register was previously used to register the
thermal sensor with the parent struct device of the IIO device,
representing the MFD device. By doing so, we registered actually the
parent in the devm routine and not the actual IIO device.
This lead to the devm unregister function not being called when the IIO
module driver is removed. It resulted in the thermal framework still
polling the get_temp function of the IIO module while the device doesn't
exist anymore, thus generated a kernel panic.
Use the non-devm function instead and do the unregister manually in the
remove function.
Fixes: d1caa99055 ("iio: adc: add support for Allwinner SoCs ADC")
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
If the driver is built as a module, it won't be autloaded if the devices
are registered via OF code because the OF device table
entries are not exported as aliases
Before the patch:
$ modinfo drivers/iio/adc/sun4i-gpadc-iio.ko | grep alias
alias: platform:sun6i-a31-gpadc-iio
alias: platform:sun5i-a13-gpadc-iio
alias: platform:sun4i-a10-gpadc-iio
After the patch:
$ modinfo drivers/iio/adc/sun4i-gpadc-iio.ko | grep alias
alias: of:N*T*Callwinner,sun8i-a33-thsC*
alias: of:N*T*Callwinner,sun8i-a33-ths
alias: platform:sun6i-a31-gpadc-iio
alias: platform:sun5i-a13-gpadc-iio
alias: platform:sun4i-a10-gpadc-iio
Signed-off-by: Eduardo Molinas <edu.molinas@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
If the driver is built as a module, it won't be autloaded if the devices
are registered via PLATFORM code because the PLATFORM device table
entries are not exported as aliases
Before the patch:
$ modinfo drivers/iio/adc/sun4i-gpadc-iio.ko | grep alias
$
After the patch:
$ modinfo drivers/iio/adc/sun4i-gpadc-iio.ko | grep alias
alias: platform:sun6i-a31-gpadc-iio
alias: platform:sun5i-a13-gpadc-iio
alias: platform:sun4i-a10-gpadc-iio
Signed-off-by: Eduardo Molinas <edu.molinas@gmail.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This adds support for the Allwinner A33 thermal sensor.
Unlike the A10, A13 and A31, the Allwinner A33 only has one channel
which is dedicated to the thermal sensor. Moreover, its thermal sensor
does not generate interruptions, thus we only need to directly read the
register storing the temperature value.
The MFD used by the A10, A13 and A31, was created to avoid breaking the
DT binding, but since the nodes for the ADC weren't there for the A33,
it is not needed.
Though the A33 does not have an internal ADC, it has a thermal sensor
which shares the same registers with GPADC of the already supported SoCs
and almost the same bits, for the same purpose (thermal sensor).
The thermal sensor behaves exactly the same (except the presence of
interrupts or not) on the different SoCs.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This moves code used in MFD probing to a new sun4i_gpadc_probe_mfd
function.
This driver was initially written for A10, A13 and A31 SoCs which
already had a DT binding for this IP, thus we needed to use an MFD to
probe the different drivers without changing the DT binding of these
SoCs.
For SoCs that will require to create a DT binding for this IP, we can
avoid using an MFD, thus we need two separate functions: one for probing
via MFD and one for probing without MFD.
This split the code specific to MFD probing in a function separated from
the driver probe function.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The following Coccinelle script was used to detect this:
@r@
expression x;
void* e;
type T;
identifier f;
@@
(
*((T *)e)
|
((T *)x)[...]
|
((T*)x)->f
|
- (T*)
e
)
Signed-off-by: simran singhal <singhalsimran0@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The Allwinner SoCs all have an ADC that can also act as a touchscreen
controller and a thermal sensor. This patch adds the ADC driver which is
based on the MFD for the same SoCs ADC.
This also registers the thermal adc channel in the iio map array so
iio_hwmon could use it without modifying the Device Tree. This registers
the driver in the thermal framework.
The thermal sensor requires the IP to be in touchscreen mode to return
correct values. Therefore, if the user is continuously reading the ADC
channel(s), the thermal framework in which the thermal sensor is
registered will switch the IP in touchscreen mode to get a temperature
value and requires a delay of 100ms (because of the mode switching),
then the ADC will switch back to ADC mode and requires also a delay of
100ms. If the ADC readings are critical to user and the SoC temperature
is not, this driver is capable of not registering the thermal sensor in
the thermal framework and thus, "quicken" the ADC readings.
This driver probes on three different platform_device_id to take into
account slight differences (registers bit and temperature computation)
between Allwinner SoCs ADCs.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
