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path: root/drivers/iio/adc/hx711.c
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2020-06-14iio: remove left-over parent assignmentsAlexandru Ardelean
These were found by doing some shell magic: ------------ for file in $(git grep -w devm_iio_device_alloc | cut -d: -f1 | sort | uniq) ; do if grep 'parent =' $file | grep -v trig | grep -vq devm_; then echo "$file -> $(grep "parent =" $file)" fi done ----------- The output is bearable [after the semantic patch is applied]. There is a mix of trigger assignments with some iio device parent assignments that are removed via this patch. JC: A few more added via inspection of all parent = statements in drivers/iio. Some of these may just have crossed with this series, others were less obvious to scripting due to some cross file / module boundary calls. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-10-22iio: adc: hx711: optimize performance in read cycleAndreas Klinger
Set gain in hx711_reset() to its default value after a reset cycle. This omits one precautionary read cycle, because the read is performed in hx711_set_gain_for_channel() anyway if gain has changed. Check for DOUT low and if its high wait some time if it goes down instead of doing a blind reset cycle when DOUT is not down. This is a performance optimization which allows to query the sensor with a higher frequency. Signed-off-by: Andreas Klinger <ak@it-klinger.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-10-09iio: adc: hx711: fix bug in sampling of dataAndreas Klinger
Fix bug in sampling function hx711_cycle() when interrupt occures while PD_SCK is high. If PD_SCK is high for at least 60 us power down mode of the sensor is entered which in turn leads to a wrong measurement. Switch off interrupts during a PD_SCK high period and move query of DOUT to the latest point of time which is at the end of PD_SCK low period. This bug exists in the driver since it's initial addition. The more interrupts on the system the higher is the probability that it happens. Fixes: c3b2fdd0ea7e ("iio: adc: hx711: Add IIO driver for AVIA HX711") Signed-off-by: Andreas Klinger <ak@it-klinger.de> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157Thomas Gleixner
Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-15iio: hx711: add delay until DOUT is readyAndreas Klinger
On a system with parasitic capacitance it turned out that DOUT is not ready after 100 ns after PD_SCK has raised. A measurement showed almost 1000 ns until DOUT has reached its correct value. With this patch its now possible to wait until data is ready. The wait time should not be higher than the maximum PD_SCK high time which is corresponding to the datasheet 50000 ns. Signed-off-by: Andreas Klinger <ak@it-klinger.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-01-08iio: hx711: fix bug in reset functionalityAndreas Klinger
Return value in hx711_reset() should indicate status of dout otherwise the calling function is reporting an error as false positive If there are two reads too close to each other, then the second one will never succeed. This happens especially when using buffered mode with both channels enabled. When changing the channel on every trigger event the former 100 ms are not enough for waiting until the device indicates normal mode. Wait up to 1 second until the device turns into normal mode. Signed-off-by: Andreas Klinger <ak@it-klinger.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-08iio: hx711: add triggered buffer supportAndreas Klinger
Add buffer to device data struct and add trigger function Data format is quite simple: voltage - channel 0 32 Bit voltage - channel 1 32 Bit timestamp 64 Bit Using both channels at the same time is working quite slow because of changing the channel which needs a dummy read. Signed-off-by: Andreas Klinger <ak@it-klinger.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-22iio:adc: drop assign iio_info.driver_module and iio_trigger_ops.ownerJonathan Cameron
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>
2017-04-01iio: adc: hx711: constify attribute_group structuressimran singhal
Check for attribute_group structures that are only stored in the attrs filed of iio_info structure. As the attrs field of iio_info structures is constant, so these attribute_group structures can also be declared constant. Done using coccinelle: @r1 disable optional_qualifier @ identifier i; position p; @@ static struct attribute_group i@p = {...}; @ok1@ identifier r1.i; position p; struct iio_info x; @@ x.attrs=&i@p; @bad@ position p!={r1.p,ok1.p}; identifier r1.i; @@ i@p @depends on !bad disable optional_qualifier@ identifier r1.i; @@ static +const struct attribute_group i={...}; @depends on !bad disable optional_qualifier@ identifier r1.i; @@ +const struct attribute_group i; File size before: text data bss dec hex filename 3042 480 0 3522 dc2 drivers/iio/adc/hx711.o File size after: text data bss dec hex filename 3098 416 0 3514 dba drivers/iio/adc/hx711.o Signed-off-by: simran singhal <singhalsimran0@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-01-10iio: adc: hx711: Add IIO driver for AVIA HX711Andreas Klinger
This is the IIO driver for AVIA HX711 ADC which is mostly used in weighting cells. The protocol is quite simple and using GPIOs: One GPIO is used as clock (SCK) while another GPIO is read (DOUT) The raw value read from the chip is delivered. To get a weight one needs to subtract the zero offset and scale it. Signed-off-by: Andreas Klinger <ak@it-klinger.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>