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2021-03-11iio: buffer: introduce support for attaching more IIO buffersAlexandru Ardelean1-2/+2
With this change, calling iio_device_attach_buffer() will actually attach more buffers. Right now this doesn't do any validation of whether a buffer is attached twice; maybe that can be added later (if needed). Attaching a buffer more than once should yield noticeably bad results. The first buffer is the legacy buffer, so a reference is kept to it. At this point, accessing the data for the extra buffers (that are added after the first one) isn't possible yet. The iio_device_attach_buffer() is also changed to return an error code, which for now is -ENOMEM if the array could not be realloc-ed for more buffers. To adapt to this new change iio_device_attach_buffer() is called last in all place where it's called. The realloc failure is a bit difficult to handle during un-managed calls when unwinding, so it's better to have this as the last error in the setup_buffer calls. At this point, no driver should call iio_device_attach_buffer() directly, it should call one of the {devm_}iio_triggered_buffer_setup() or devm_iio_kfifo_buffer_setup() or devm_iio_dmaengine_buffer_setup() functions. This makes iio_device_attach_buffer() a bit easier to handle. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20210215104043.91251-20-alexandru.ardelean@analog.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-11-21iio: buffer: remove iio_buffer_set_attrs() helperAlexandru Ardelean1-3/+0
The iio_buffer_set_attrs() is no longer used in the drivers, so it can be removed now. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20200929125949.69934-10-alexandru.ardelean@analog.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 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 version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10iio:buffer.h - split into buffer.h and buffer_impl.hJonathan Cameron1-155/+1
buffer.h supplies everything needed for devices using buffers. buffer_impl.h supplies access to the internals as needed to write a buffer implementation. This was really motivated by the mess that turned up in the kernel-doc documentation pulled in by the new sphinx docs. It made it clear that our logical separations in headers were generally terrible. The buffer case was easy to sort out without greatly effecting drivers so here it is. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-01-10iio:buffer: Push implementation of iio_device_attach_buffer into .c fileJonathan Cameron1-14/+2
This is a precursor to the splitting of buffer.h into parts relevant to buffer implementation vs those for devices using buffers. struct buffer is about to become opaque as far as the header is concerned. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-01-10iio:buffer:iio_push_to_buffers_with_timestamp fix kernel-doc.Jonathan Cameron1-1/+1
Wrong start of kernel doc comment /* -> /** Signed-off-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-01-10iio:buffers: Push some docs down into the .c file.Jonathan Cameron1-5/+0
Ancient legacy of me doing it wrong which it is nice to clear up whilst we are here. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-01-10iio:buffer: Stop exporting iio_scan_mask_queryJonathan Cameron1-3/+0
Nothing uses it outside of core code. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-01-10iio:buffer: Introduced a function to assign the buffer specific attrs.Jonathan Cameron1-0/+2
This is a necessary step in taking the buffer implementation opaque. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-01-10iio:buffer.h Reformat structure comments to be inline.Jonathan Cameron1-37/+63
This should make it easier to see how the structure is split into public and private parts - reflected in the generated documentation. Deliberately use /* instead of /** for the private elements to avoid warnings when kernel-doc script runs. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-01-10iio:buffer: Stop exporting iio_update_demuxJonathan Cameron1-2/+0
Nothing outside of indiustrialio-buffer.c should be using this. Requires a large amount of juggling of functions to avoid a forward definition. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2016-04-03iio: buffer: add missing descriptions in iio_buffer_access_funcsLuis de Bethencourt1-0/+2
The members buffer_group and attrs of iio_buffer_access_funcs have no descriptions for the documentation. Adding them. Fixes: 08e7e0adaa17 ("iio: buffer: Allocate standard attributes in the core") Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-10-25iio: Add buffer enable/disable callbacksLars-Peter Clausen1-0/+8
This patch adds a enable and disable callback that is called when the buffer is enabled/disabled. This can be used by buffer implementations that need to do some setup or teardown work. E.g. a DMA based buffer can use this to start/stop the DMA transfer. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-10-25iio: Add support for indicating fixed watermarksLars-Peter Clausen1-0/+8
For buffers which have a fixed wake-up watermark the watermark attribute should be read-only. Add a new FIXED_WATERMARK flag to the struct iio_buffer_access_funcs, which can be set by a buffer implementation. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-06-01iio: Specify supported modes for buffersLars-Peter Clausen1-0/+3
For each buffer type specify the supported device modes for this buffer. This allows us for devices which support multiple different operating modes to pick the correct operating mode based on the modes supported by the attached buffers. It also prevents that buffers with conflicting modes are attached to a device at the same time or that a buffer with a non-supported mode is attached to a device (e.g. in-kernel callback buffer to a device only supporting hardware mode). Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-03-29iio: add watermark logic to iio read and pollJosselin Costanzi1-3/+5
Currently the IIO buffer blocking read only wait until at least one data element is available. This patch makes the reader sleep until enough data is collected before returning to userspace. This should limit the read() calls count when trying to get data in batches. Co-author: Yannick Bedhomme <yannick.bedhomme@mobile-devices.fr> Signed-off-by: Josselin Costanzi <josselin.costanzi@mobile-devices.fr> [rebased and remove buffer timeout] Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-12-12iio: buffer: Drop get_length callbackLars-Peter Clausen1-2/+0
We already do have the length field in the struct iio_buffer which is expected to be in sync with the current size of the buffer. And currently all implementations of the get_length callback either return this field or a constant number. This patch removes the get_length callback and replaces all occurrences in the IIO core with directly accessing the length field of the buffer. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-12-12iio: buffer: Allocate standard attributes in the coreLars-Peter Clausen1-35/+2
All buffers want at least the length and the enable attribute. Move the creation of those attributes to the core instead of having to do this in each individual buffer implementation. This allows us to get rid of some boiler-plate code. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-12-12iio: Remove get_bytes_per_datum() from iio_buffer_access_funcsLars-Peter Clausen1-2/+0
There haven't been any users of the get_bytes_per_datum() callback for a while. The core assumes that the number of bytes per datum can be calculated based on the enabled channels and the storage size of the channel and iio_compute_scan_bytes() is used to compute this number. So remove the callback. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-12-12iio: Move buffer registration to the coreLars-Peter Clausen1-26/+0
Originally device and buffer registration were kept as separate operations in IIO to allow to register two distinct sets of channels for buffered and non-buffered operations. This has since already been further restricted and the channel set registered for the buffer needs to be a subset of the channel set registered for the device. Additionally the possibility to not have a raw (or processed) attribute for a channel which was registered for the device was added a while ago. This means it is possible to not register any device level attributes for a channel even if it is registered for the device. Also if a channel's scan_index is set to -1 and the channel is registered for the buffer it is ignored. So in summary it means it is possible to register the same channel array for both the device and the buffer yet still end up with distinctive sets of channels for both of them. This makes the argument for having to have to manually register the channels for both the device and the buffer invalid. Considering that the vast majority of all drivers want to register the same set of channels for both the buffer and the device it makes sense to move the buffer registration into the core to avoid some boiler-plate code in the device driver setup path. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-12-12iio: Unexport iio_scan_mask_set()Lars-Peter Clausen1-9/+0
Individual drivers should not be messing with the scan mask that contains the list of enabled channels. This is something that is supposed to be managed by the core. Now that the last few drivers that used it to configure a default scan mask have been updated to not do this anymore we can unexport the function. Note, this patch also requires moving a few functions around so they are all declared before the first internal user. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Daniel Baluta <daniel.baluta@intel.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-12-04iio: Add data_available callback for buffersLars-Peter Clausen1-0/+3
This patch adds a new data_available() callback to the iio_buffer_access_funcs struct. The callback is used to indicate whether data is available in the buffer for reading. It is meant to replace the stufftoread flag from the iio_buffer struct. The reasoning for this is that the buffer implementation usually can determine whether data is available rather easily based on its state, on the other hand it can be rather tricky to update the stufftoread flag in a race free way. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-16iio: Remove unused iio_sw_buffer_preenable()Lars-Peter Clausen1-2/+0
The functionality implemented by iio_sw_buffer_preenable() is now done directly in the IIO core and previous users of iio_sw_buffer_preenable() have all been updated to not use it anymore. It is unused now and can be remove. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-12iio: Add reference counting for buffersLars-Peter Clausen1-0/+28
Since the buffer is accessed by userspace we can not just free the buffers memory once we are done with it in kernel space. There might still be open file descriptors and userspace still might be accessing the buffer. This patch adds support for reference counting to the IIO buffers. When a buffer is created and initialized its initial reference count is set to 1. Instead of freeing the memory of the buffer the buffer's _free() function will drop that reference again. But only after the last reference to the buffer has been dropped the buffer the buffer's memory will be freed. The IIO device will take a reference to its primary buffer. The patch adds a small helper function for this called iio_device_attach_buffer() which will get a reference to the buffer and assign the buffer to the IIO device. This function must be used instead of assigning the buffer to the device by hand. The reference is only dropped once the IIO device is freed and we can be sure that there are no more open file handles. A reference to a buffer will also be taken whenever the buffer is active to avoid the buffer being freed while data is still being send to it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-21iio: Add iio_push_buffers_with_timestamp() helperLars-Peter Clausen1-0/+25
Drivers using software buffers often store the timestamp in their data buffer before calling iio_push_to_buffers() with that data buffer. Storing the timestamp in the buffer usually involves some ugly pointer arithmetic. This patch adds a new helper function called iio_push_buffers_with_timestamp() which is similar to iio_push_to_buffers but takes an additional timestamp parameter. The function will help to hide to uglyness in one central place instead of exposing it in every driver. If timestamps are enabled for the IIO device iio_push_buffers_with_timestamp() will store the timestamp as the last element in buffer, before passing the buffer on to iio_push_buffers(). The buffer needs large enough to hold the timestamp in this case. If timestamps are disabled iio_push_buffers_with_timestamp() will behave just like iio_push_buffers(). Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Cc: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com> Cc: Josh Wu <josh.wu@atmel.com> Cc: Denis Ciocca <denis.ciocca@gmail.com> Cc: Manuel Stahl <manuel.stahl@iis.fraunhofer.de> Cc: Ge Gao <ggao@invensense.com> Cc: Peter Meerwald <pmeerw@pmeerw.net> Cc: Jacek Anaszewski <j.anaszewski@samsung.com> Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Marek Vasut <marex@denx.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-15iio: iio_push_to_buffers(): Change type of 'data' to const void *Lars-Peter Clausen1-3/+3
Change the type of the 'data' parameter for iio_push_to_buffers() from 'u8 *' to 'const void *'. Drivers typically use the correct type (e.g. __be16 *) for their data buffer. When passing the buffer to iio_push_to_buffers() it needs to be cast to 'u8 *' for the compiler to not complain (and also having to add __force if we want to keep sparse happy as well). Since the buffer implementation should not care about the data layout (except the size of one sample) using a void pointer is the correct thing to do. Also make it const as the buffer implementations are not supposed to modify it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-01-31staging:iio: Remove noop call to __iio_update_bufferLars-Peter Clausen1-13/+0
__iio_update_buffer updates the buffer's bytes_per_datum and length fields. But the only user of this function just passes in these exact fields, so the call basically looks like this: buffer->bytes_per_datum = buffer->bytes_per_datum; buffer->length = buffer->length; Which means it is a noop and can be removed. Also remove the function itself, since it is now unused. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-11-20iio: Fix iio_buffer_register stub signatureLars-Peter Clausen1-1/+1
Match the iio_buffer_register stub signature up to the real function and make the second parameter const. This fixes a the following warnings if CONFIG_IIO_BUFFER is disabled: drivers/staging/iio/accel/adis16201_core.c: In function ‘adis16201_probe’: drivers/staging/iio/accel/adis16201_core.c:536: warning: passing argument 2 of ‘iio_buffer_register’ discards qualifiers from pointer target type drivers/staging/iio/accel/adis16203_core.c: In function ‘adis16203_probe’: drivers/staging/iio/accel/adis16203_core.c:468: warning: passing argument 2 of ‘iio_buffer_register’ discards qualifiers from pointer target type drivers/staging/iio/accel/adis16204_core.c: In function ‘adis16204_probe’: drivers/staging/iio/accel/adis16204_core.c:527: warning: passing argument 2 of ‘iio_buffer_register’ discards qualifiers from pointer target type drivers/staging/iio/accel/adis16209_core.c: In function ‘adis16209_probe’: drivers/staging/iio/accel/adis16209_core.c:542: warning: passing argument 2 of ‘iio_buffer_register’ discards qualifiers from pointer target type drivers/staging/iio/accel/adis16240_core.c: In function ‘adis16240_probe’: drivers/staging/iio/accel/adis16240_core.c:588: warning: passing argument 2 of ‘iio_buffer_register’ discards qualifiers from pointer target type Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-11-10staging:iio: Add support for multiple buffersJonathan Cameron1-5/+19
Route all buffer writes through the demux. Addition or removal of a buffer results in tear down and setup of all the buffers for a given device. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Tested-by: srinivas pandruvada <srinivas.pandruvada@intel.com>
2012-09-08iio: Drop timestamp parameter from buffer store_to callbackLars-Peter Clausen1-4/+2
Drop timestamp parameter from buffer store_to callback and subsequently from iio_push_to_buffer. The timestamp parameter is unused and it seems likely that it will stay unused in the future, so it should be safe to remove it. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-07-09iio: Introduce iio_validate_scan_mask_onehotLars-Peter Clausen1-0/+3
Add a helper function for validating a scan mask for devices where exactly one channel must be selected during sampling. This is a common case among devices which have scan mask restrictions so it makes sense to provide this function in the core. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-07-07iio: cleanup buffer.h commentsPeter Meerwald1-7/+10
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-06-19iio: remove extra ; after function definitionPeter Meerwald1-1/+1
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-25IIO: Move core headers to include/linux/iioJonathan Cameron1-0/+191
Step 1 in moving the IIO core out of staging. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>