This code is problematic because we're supposed to be writing an int but
we instead write to only the high 16 bits. This doesn't work on big
endian systems, and there is a potential that the bottom 16 bits are
used without being initialized.
Fixes: 23ec2774f1 ("iio: adc: at91-sama5d2_adc: add support for position and pressure channels")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This implements oversampling support for the SAMA5d2 ADC device.
Enabling oversampling : OSR can improve resolution from 12 bits to
13 or 14 bits.
Changing the channel specification to have 14 bits, and we shift the value
1 bit to the left if we have oversampling for just one extra bit, and two
bits to the left if we have no oversampling (old support).
From this commit on, the converted values for all the voltage channels
change to 14 bits real data, with most insignificant two bits always zero
if oversampling is not enabled.
sysfs object oversampling_ratio has been enabled and
oversampling_ratio_available will list possible values (1 or 4 or 16) having
1 as default (no oversampling, 1 sample for each conversion).
Special care was required for the triggered buffer scenario (+ DMA), to
adjust the values accordingly.
Touchscreen measurements supported by this driver are not affected by
oversampling, they are still on 12 bits (scale handing is already included
in the driver).
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This implements the support for position and pressure for the included
touchscreen support in the SAMA5D2 SOC ADC block.
Two position channels are added and one for pressure.
They can be read in raw format, or through a buffer.
A normal use case is for a consumer driver to register a callback buffer
for these channels.
When the touchscreen channels are in the active scan mask,
the driver will start the touchscreen sampling and push the data to the
buffer.
Some parts of this patch are based on initial original work by
Mohamed Jamsheeth Hajanajubudeen and Bandaru Venkateswara Swamy
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
When iterating through the channels, the index in the array is not the
scan index. Added an xlate function to translate to the proper index.
The result of the bug is that the channel array is indexed with a wrong index,
thus instead of the proper channel, we access invalid memory, which may
lead to invalid results and/or corruption.
This will be used also for devicetree channel xlate.
Fixes: 5e1a1da0f ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Fixes: 073c66201 ("iio: adc: at91-sama5d2_adc: add support for DMA")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Need to acknowledge DRDY irq in direct mode/ software
triggered mode. Otherwise, on the next conversion, overrun
flag will be raised, which is not a correct state.
This doesn't affect the functionality, but will generate
possible incorrect overrun reports.
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Added support for DMA transfers. The implementation uses the user watermark
to decide whether DMA will be used or not. For watermark 1, DMA will not be
used. If watermark is bigger, DMA will be used.
Sysfs attributes are created to indicate whether the DMA is used,
with hwfifo_enabled, and the current DMA watermark is readable
in hwfifo_watermark. Minimum and maximum values are in hwfifo_watermark_min
and hwfifo_watermark_max.
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This fix allows platforms to probe correctly even if the
trigger edge property is missing. The hardware trigger
will no longer be registered in the sybsystem
Preserves backwards compatibility with the support that
was in the driver before the hardware trigger.
https://storage.kernelci.org/mainline/master/v4.14-rc2-255-g74d83ec2b734/arm/sama5_defconfig/lab-free-electrons/boot-at91-sama5d2_xplained.txt
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Fixes: 5e1a1da0f ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The equivalent of both of these are now done via macro magic when
the relevant register calls are made. The actual structure
elements will shortly go away.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Making the const array startup_lookup static rather having it on the
stack saves 69 bytes. Add in missing int specifier to clean up a
checkpatch warning.
Before:
text data bss dec hex filename
10297 2800 128 13225 33a9 drivers/iio/adc/at91-sama5d2_adc.o
After:
text data bss dec hex filename
10140 2888 128 13156 3364 drivers/iio/adc/at91-sama5d2_adc.o
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Added support for suspend/resume functionality for the ADC IP
in sama5d2 SoC.
In order to enter Suspend to ram mode (backup + self refresh mode for
memory), in which the ADC IP is no longer powered, we need to reset the
pins to default state, for the scenario when they are also used for I2C
bus to communicate with the PMIC.
On resume, we need to reconfigure the ADC IP registers and reconfigure the
trigger registers in the case when the suspend procedure is done while
sysfs has the buffer and trigger enabled.
In the case the suspend happens exactly during a software triggered
conversion, the request will time out, because we reset and power down
the ADC.
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Added support for the external hardware trigger on pin ADTRG,
integrated the three possible edges into the driver
and created buffer management for data retrieval
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add signed differential channels and update the voltage scale for
differential conversions.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Do not erase previous configuration of the mode register when setting
the sampling frequency.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Use var type for sizeof argument instead of the struct name.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
vref_uv has to be an int.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This driver supports the new version of the Atmel ADC device introduced
with the SAMA5D2 SoC family.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
