Commit 7383d44b added a pointer pdata which get set to the default
platform_data when non was defined in the device. But it did not
pass this pointer to the st_sensors_init_sensor call but still
used the maybe uninitialized platform_data from dev.

This breaks initialization when no platform_data is given and
the optional st,drdy-int-pin devicetree option is not set.

This commit fixes this.

Cc: stable@vger.kernel.org
Fixes: 7383d44b ("iio: st_pressure: st_accel: Initialise sensor platform data properly")
Signed-off-by: Michael Nosthoff <committed@heine.so>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This reverts commit 585ed27d06151f98e39238298f43ee261314ae74.

This removed code which was unused due to a bug in commit 7383d44b.
To fix this bug the code is needed. Thus this revert.

Signed-off-by: Michael Nosthoff <committed@heine.so>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The meson_sar_adc_lock() function is not supposed to hold the
"indio_dev->mlock" on the error path.

Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

When several channels are registered (e.g. via st,adc-channels property):
- channels array is wrongly filled in. Only 1st element in array is being
  initialized with last registered channel.
  Fix it by passing reference to relevant channel (e.g. array[index]).
- only last initialized channel can work properly (e.g. unique 'ch_id'
  is used). Converting any other channel result in conversion timeout.
  Fix it by getting rid of 'ch_id', use chan->channel instead.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add missing clock source selection. In case "audio" clock is provided,
it's unused currently: "dfsdm" clock is wrongly used by default.

Fixes: bed73904e76f ("IIO: ADC: add stm32 DFSDM core support")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

stm32_dfsdm_stop_channel must be called with channel id, not filter id.

Fixes: e2e6771c6462 ("IIO: ADC: add STM32 DFSDM sigma delta ADC support")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Fix use of compatible data: stm32h7 regmap configuration is statically
used. Rather use regmap_cfg from compatible data.

Fixes: bed73904e76f ("IIO: ADC: add stm32 DFSDM core support")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

CCS811 has different I2C register maps in boot and application mode. When
CCS811 is in boot mode, register APP_START (0xF4) is used to transit the
firmware state from boot to application mode. However, APP_START is not a
valid register location when CCS811 is in application mode (refer to
"CCS811 Bootloader Register Map" and "CCS811 Application Register Map" in
CCS811 datasheet). The driver should not attempt to perform a write to
APP_START while CCS811 is in application mode, as this is not a valid or
documented register location.

When prob function is being called, the driver assumes the CCS811 sensor
is in boot mode, and attempts to perform a write to APP_START. Although
CCS811 powers-up in boot mode, it may have already been transited to
application mode by previous instances, e.g. unload and reload device
driver by the system, or explicitly by user. Depending on the system
design, CCS811 sensor may be permanently connected to system power source
rather than power controlled by GPIO, hence it is possible that the sensor
is never power reset, thus the firmware could be in either boot or
application mode at any given time when driver prob function is being
called.

This patch checks the STATUS register before attempting to send a write to
APP_START. Only if the firmware is not in application mode and has valid
firmware application loaded, then it will continue to start transiting the
firmware boot to application mode.

Signed-off-by: Richard Lai <richard@richardman.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Jonathan writes:

First round of IIO fixes for the 4.16 cycle.

One nasty very old crash around polling for buffers that aren't there
- though that can only cause effects on drivers that support events
but not buffers.

* buffer / kfifo handling in the core.
  - Check there is a buffer and return 0 from poll directly if there
    isn't.  Poll doesn't make sense in this circumstances, but best to close
    the hole.
* ad5933
  - Change the marked buffer mode to a software buffer as the meaning of
    the hardware buffer label has long since changed and this uses a front
    end software buffer anyway.
* ad7192
  - Fix the fact the external clock frequency was only set when using the
    internal clock which was less than helpful.
* adis_lib
  - Initialize the trigger before requesting the interrupt.  Some newer
    parts can power up with interrupt generation enabled so ordering now
    matters.
* aspeed-adc
  - Fix an errror handling path as labels and general ordering were wrong.
* srf08
  - Fix a link error due to undefined devm_iio_triggered_buffer_setup.
* stm32-adc
  - Fix error handling unwind squence in stm32h7_adc_enable.

If no iio buffer has been set up and poll is called return 0.
Without this check there will be a null pointer dereference when
calling poll on a iio driver without an iio buffer.

Cc: stable@vger.kernel.org
Signed-off-by: Stefan Windfeldt-Prytz <stefan.windfeldt@axis.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>