commit d7857e4ee1 upstream.
This patch fixes device tree channel configuration.
ad7124 driver reads channels configuration from the device tree.
It expects to find channel specifications as child nodes.
Before this patch ad7124 driver assumed that the child nodes are parsed
by for_each_available_child_of_node in the order 0,1,2,3...
This is wrong and the real order of the children can be seen by running:
dtc -I fs /sys/firmware/devicetree/base on the machine.
For example, running this on an rpi 3B+ yields the real
children order: 4,2,0,7,5,3,1,6
Before this patch the driver assigned the channel configuration
like this:
- 0 <- 4
- 1 <- 2
- 2 <- 0
........
For example, the symptoms can be observed by connecting the 4th channel
to a 1V tension and then reading the in_voltage0-voltage19_raw sysfs
(multiplied of course by the scale) one would see that channel 0
measures 1V and channel 4 measures only noise.
Now the driver uses the reg property of each child in order to
correctly identify to which channel the parsed configuration
belongs to.
Fixes b3af341bbd966: ("iio: adc: Add ad7124 support")
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 11d7c8d3b1 upstream.
When the internal reference was selected by a channel it was not enabled.
This patch fixes that and enables it.
Fixes: b3af341bbd ("iio: adc: Add ad7124 support")
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch changes the channel configuration member of the device
structure from a fixed size array to a dynamic allocated one with a size
equal to the number of channels specified in the device tree. This will
ensure a more flexibility for compatible devices.
Ex. ad7124-4 - can have 4 differential or 8 pseudo-differential channels
ad7124-8 - can have 8 differential or 16 pseudo-differential channels
Also the device can suspport any other combination of differential and
pseudo-differential channels base on the physical number of inputs
available.
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This patch adds the option to enable the buffered mode for positive and
negative inputs. Each option can be enabled independently.
In buffered mode, the input channel feeds into a high impedance input stage
of the buffer amplifier. Therefore, the input can tolerate significant
source impedances and is tailored for direct connection to external
resistive type sensors such as strain gages or RTDs.
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The driver limits the user to use only 4/8 differential inputs, but this
device has the option to use pseudo-differential channels. This will
increase the number of channels to be equal with the number of inputs so 8
channels for ad7124-4 and 16 for ad7124-8.
This patch removes the check between channel nodes and num_inputs value.
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
A return statement is indented one level too deeply; clean this
up by removing a tab.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The ad7124-4 and ad7124-8 are a family of 4 and 8 channel sigma-delta ADCs
with 24-bit precision and reference.
Three power modes are available which in turn affect the output data rate:
* Full power: 9.38 SPS to 19,200 SPS
* Mid power: 2.34 SPS to 4800 SPS
* Low power: 1.17 SPS to 2400 SPS
The ad7124-4 can be configured to have four differential inputs, while
ad7124-8 can have 8. Moreover, ad7124 also supports per channel
configuration. Each configuration consists of gain, reference source,
output data rate and bipolar/unipolar configuration.
Datasheets:
Link: http://www.analog.com/media/en/technical-documentation/data-sheets/AD7124-4.pdf
Link: http://www.analog.com/media/en/technical-documentation/data-sheets/ad7124-8.pdf
Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Alexandru Tachici