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path: root/drivers/iio/industrialio-buffer.c
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2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
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>
2019-04-21Merge 5.1-rc6 into staging-nextGreg Kroah-Hartman
We want the fixes in here as well as this resolves an iio driver merge issue. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-04iio: buffer: Switch to bitmap_zalloc()Andy Shevchenko
Switch to bitmap_zalloc() to show clearly what we are allocating. Besides that it returns pointer of bitmap type instead of opaque void *. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-03-09iio: Fix scan mask selectionLars-Peter Clausen
The trialmask is expected to have all bits set to 0 after allocation. Currently kmalloc_array() is used which does not zero the memory and so random bits are set. This results in random channels being enabled when they shouldn't. Replace kmalloc_array() with kcalloc() which has the same interface but zeros the memory. Note the fix is actually required earlier than the below fixes tag, but will require a manual backport due to move from kmalloc to kmalloc_array. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Fixes commit 057ac1acdfc4 ("iio: Use kmalloc_array() in iio_scan_mask_set()"). Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-02-20Merge tag 'iio-fixes-for-4.16a' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus 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.
2018-02-17iio: buffer: check if a buffer has been set up when poll is calledStefan Windfeldt-Prytz
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>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-01Merge tag 'staging-4.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging/IIO updates from Greg KH: "Here is the big Staging and IIO driver patches for 4.16-rc1. There is the normal amount of new IIO drivers added, like all releases. The networking IPX and the ncpfs filesystem are moved into the staging tree, as they are on their way out of the kernel due to lack of use anymore. The visorbus subsystem finall has started moving out of the staging tree to the "real" part of the kernel, and the most and fsl-mc codebases are almost ready to move out, that will probably happen for 4.17-rc1 if all goes well. Other than that, there is a bunch of license header cleanups in the tree, along with the normal amount of coding style churn that we all know and love for this codebase. I also got frustrated at the Meltdown/Spectre mess and took it out on the dgnc tty driver, deleting huge chunks of it that were never even being used. Full details of everything is in the shortlog. All of these patches have been in linux-next for a while with no reported issues" * tag 'staging-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (627 commits) staging: rtlwifi: remove redundant initialization of 'cfg_cmd' staging: rtl8723bs: remove a couple of redundant initializations staging: comedi: reformat lines to 80 chars or less staging: lustre: separate a connection destroy from free struct kib_conn Staging: rtl8723bs: Use !x instead of NULL comparison Staging: rtl8723bs: Remove dead code Staging: rtl8723bs: Change names to conform to the kernel code staging: ccree: Fix missing blank line after declaration staging: rtl8188eu: remove redundant initialization of 'pwrcfgcmd' staging: rtlwifi: remove unused RTLHALMAC_ST and RTLPHYDM_ST staging: fbtft: remove unused FB_TFT_SSD1325 kconfig staging: comedi: dt2811: remove redundant initialization of 'ns' staging: wilc1000: fix alignments to match open parenthesis staging: wilc1000: removed unnecessary defined enums typedef staging: wilc1000: remove unnecessary use of parentheses staging: rtl8192u: remove redundant initialization of 'timeout' staging: sm750fb: fix CamelCase for dispSet var staging: lustre: lnet/selftest: fix compile error on UP build staging: rtl8723bs: hal_com_phycfg: Remove unneeded semicolons staging: rts5208: Fix "seg_no" calculation in reset_ms_card() ...
2018-01-08iio: buffer: Expose data availableMatt Fornero
Add a sysfs attribute that exposes buffer data available to userspace. This attribute can be checked at runtime to determine the overall buffer fill level (across all allocated buffers). Signed-off-by: Matt Fornero <matt.fornero@mathworks.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28the rest of drivers/*: annotate ->poll() instancesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-10iio:buffer.h - split into buffer.h and buffer_impl.hJonathan Cameron
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 Cameron
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:buffers: Push some docs down into the .c file.Jonathan Cameron
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 Cameron
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 Cameron
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: Stop exporting iio_update_demuxJonathan Cameron
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>
2016-09-24iio: Use kmalloc_array() in iio_scan_mask_set()Markus Elfring
A multiplication for the size determination of a memory allocation indicated that an array data structure should be processed. Thus use the corresponding function "kmalloc_array". This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-09-05iio: ensure ret is initialized to zero before entering do loopColin Ian King
A recent fix to iio_buffer_read_first_n_outer removed ret from being set by a return from wait_event_interruptible and also added a continue in a loop which causes the variable ret to not be set when it reaches the end of the loop. Fix this by initializing ret to zero. Also remove extraneous white space at the end of the loop. Fixes: fcf68f3c0bb2a5 ("fix sched WARNING "do not call blocking ops when !TASK_RUNNING") Signed-off-by: Colin Ian King <colin.king@canonical.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-08-21iio: fix sched WARNING "do not call blocking ops when !TASK_RUNNING"Brian Norris
When using CONFIG_DEBUG_ATOMIC_SLEEP, the scheduler nicely points out that we're calling sleeping primitives within the wait_event loop, which means we might clobber the task state: [ 10.831289] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffc00026b610>] [ 10.845531] ------------[ cut here ]------------ [ 10.850161] WARNING: at kernel/sched/core.c:7630 ... [ 12.164333] ---[ end trace 45409966a9a76438 ]--- [ 12.168942] Call trace: [ 12.171391] [<ffffffc00024ed44>] __might_sleep+0x64/0x90 [ 12.176699] [<ffffffc000954774>] mutex_lock_nested+0x50/0x3fc [ 12.182440] [<ffffffc0007b9424>] iio_kfifo_buf_data_available+0x28/0x4c [ 12.189043] [<ffffffc0007b76ac>] iio_buffer_ready+0x60/0xe0 [ 12.194608] [<ffffffc0007b7834>] iio_buffer_read_first_n_outer+0x108/0x1a8 [ 12.201474] [<ffffffc000370d48>] __vfs_read+0x58/0x114 [ 12.206606] [<ffffffc000371740>] vfs_read+0x94/0x118 [ 12.211564] [<ffffffc0003720f8>] SyS_read+0x64/0xb4 [ 12.216436] [<ffffffc000203cb4>] el0_svc_naked+0x24/0x28 To avoid this, we should (a la https://lwn.net/Articles/628628/) use the wait_woken() function, which avoids the nested sleeping while still handling races between waiting / wake-events. Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Cc: <Stable@vger.kernel.org> # 3.19+ for introduction of wake_woken Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-03-28iio: fix config watermark initial valueIrina Tirdea
config structure is set to 0 when updating the buffers, so by default config->watermark will be 0. When computing the minimum between config->watermark and the buffer->watermark or insert_buffer-watermark, this will always be 0 regardless of the value set by the user for the buffer. Set as initial value for config->watermark the maximum allowed value so that the minimum value will always be set from one of the buffers. Signed-off-by: Irina Tirdea <irina.tirdea@intel.com> Fixes: f0566c0c405d ("iio: Set device watermark based on watermark of all attached buffers") Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-02-06iio: Add helper function for calculating scan index storage sizeLars-Peter Clausen
We have the same code for computing the scan index storage size in bytes all over the place. Factor this out into helper functions. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Daniel Baluta <daniel.baluta@intel.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-12-13Merge 4.4-rc5 into staging-nextGreg Kroah-Hartman
We want those fixes in here for testing. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-21iio: fix some warning messagesDan Carpenter
WARN_ON() only takes a condition argument. I have changed these to WARN() instead. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-10-25iio: Add buffer enable/disable callbacksLars-Peter Clausen
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 Clausen
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>
2015-10-25iio:iio_buffer_init(): Only set watermark if not already setLars-Peter Clausen
Only initialize the watermark field if it is still 0. This allows drivers to provide a custom default watermark value. E.g. some driver might have a fixed watermark or can only support watermarks within a certain range and the initial value for the watermark should be within this range. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-10-25iio: Set device watermark based on watermark of all attached buffersLars-Peter Clausen
Currently the watermark of the device is only set based on the watermark that is set for the user space buffer. This doesn't consider the watermarks set on any attached in-kernel buffers. Change this so that the watermark of the device should be the minimum of the watermarks over all attached buffers. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-08-12iio: industrialio-buffer: Fix iio_buffer_poll return valueCristina Opriceana
Change return value to 0 if no device is bound since unsigned int cannot support negative error codes. Fixes: f18e7a068 ("iio: Return -ENODEV for file operations if the device has been unregistered") Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-08-02iio: buffer: Fix kernel docs warningsCristina Opriceana
Fix kernel docs for structures and functions in order to remove some warnings when the documentation gets generated. Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-06-21iio: allow userspace to flush the hwfifo with non-blocking readsOctavian Purdila
This patch changes the semantics of non-blocking reads so that a hardware fifo flush is triggered if the available data in the device buffer is less then the requested size. This allows userspace to accurately generate hardware fifo flushes, by doing a non-blocking read with a size greater then the sum of the device buffer and hardware fifo size. 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>
2015-06-01iio: Require strict scan mask matching in hardware modeLars-Peter Clausen
In hardware mode we can not use the software demuxer, this means that the selected scan mask needs to match one of the available scan masks exactly. It also means that all attached buffers need to use the same scan mask. Given that when operating in hardware mode there is typically only a single buffer attached to the device this not an issue. Add a sanity check to make sure that only a single buffer is attached in hardware mode nevertheless. 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 Clausen
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>
2015-06-01iio: Always compute masklengthLars-Peter Clausen
Even if no userspace consumer buffer is attached to the IIO device at registration we still need to compute the masklength, since it is possible that a in-kernel consumer buffer is going to get attached to the device at a later point. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-06-01iio: buffer: remove unneeded testLaurent Navet
The same code is executed regardless ret value, so this test can be removed. Also fix coverity scan CID 1268786. Signed-off-by: Laurent Navet <laurent.navet@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-05-23iio: __iio_update_buffers: Leave device in sane state on errorLars-Peter Clausen
Currently when something goes wrong at some step when disabling the buffers we immediately abort. This has the effect that the enable/disable calls are no longer balanced. So make sure that even if one step in the disable sequence fails the other steps are still executed. The other issue is that when either enable or disable fails buffers that were active at that time stay active while the device itself is disabled. This leaves things in a inconsistent state and can cause unbalanced enable/disable calls. Furthermore when enable fails we restore the old scan mask, but still keeps things disabled. Given that verification of the configuration was performed earlier and it is valid at the point where we try to enable/disable the most likely reason of failure is a communication failure with the device or maybe a out-of-memory situation. There is not really a good recovery strategy in such a case, so it makes sense to leave the device disabled, but we should still leave it in a consistent state. What the patch does if disable/enable fails is to deactivate all buffers and make sure that the device will be in the same state as if all buffers had been manually disabled. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-05-23iio: __iio_update_buffers: Split enable and disable path into helper functionsLars-Peter Clausen
__iio_update_buffers is already a rather large function with many different error paths and it is going to get even larger. This patch factors out the device enable and device disable paths into separate helper functions. The patch also re-implements iio_disable_all_buffers() using the new iio_disable_buffers() function removing a fair bit of redundant code. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-05-23iio: __iio_update_buffers: Verify configuration before starting to apply itLars-Peter Clausen
Currently __iio_update_buffers() verifies whether the new configuration will work in the middle of the update sequence. This means if the new configuration is invalid we need to rollback the changes already made. This patch moves the validation of the new configuration at the beginning of __iio_update_buffers() and will not start to make any changes if the new configuration is invalid. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-05-17iio: __iio_update_buffers: Perform request_update() only for new buffersLars-Peter Clausen
We only have to call the request_update() callback for a newly inserted buffer. The configuration of the already previously active buffers will not have changed. This also allows us to move the request_update() call to the beginning of __iio_update_buffers(), before any currently active buffers are stopped. This makes the error handling a lot easier since no changes were made to the buffer list and no rollback needs to be performed. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-05-17iio: __iio_update_buffers: Slightly refactor scan mask memory managementLars-Peter Clausen
Add a small helper function iio_free_scan_mask() that takes a mask and frees its memory if the scan masks for the device are dynamically allocated, otherwise does nothing. This means we don't have to open-code the same check over and over again in __iio_update_buffers. Also free compound_mask as soon a we are done using it. This constrains its usage to a specific region of the function will make further refactoring and splitting the function into smaller sub-parts more easier. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-05-17iio: Replace printk in __iio_update_buffers with dev_dbgLars-Peter Clausen
While more verbose error messages are useful for debugging we should really not put those error messages into the kernel log for normal errors that are already reported to the application via the error code, when running in non-debug mode. Otherwise application authors might expect that this is part of the ABI and to get the error they should scan the kernel log. Which would be rather error prone itself since there is no direct mapping between a operation and the error message so it is impossible to find out which error message belongs to which error. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-03-29iio: add support for hardware fifoOctavian Purdila
Some devices have hardware buffers that can store a number of samples for later consumption. Hardware usually provides interrupts to notify the processor when the FIFO is full or when it has reached a certain watermark level. This helps with reducing the number of interrupts to the host processor and thus it helps decreasing the power consumption. This patch enables usage of hardware FIFOs for IIO devices in conjunction with software device buffers. When the hardware FIFO is enabled the samples are stored in the hardware FIFO. The samples are later flushed to the device software buffer when the number of entries in the hardware FIFO reaches the hardware watermark or when a flush operation is triggered by the user when doing a non-blocking read on an empty software device buffer. In order to implement hardware FIFO support the device drivers must implement the following new operations: setting and getting the hardware FIFO watermark level, flushing the hardware FIFO to the software device buffer. The device must also expose information about the hardware FIFO such it's minimum and maximum watermark and if necessary a list of supported watermark values. Finally, the device driver must activate the hardware FIFO when the device buffer is enabled, if the current device settings allows it. The software device buffer watermark is passed by the IIO core to the device driver as a hint for the hardware FIFO watermark. The device driver can adjust this value to allow for hardware limitations (such as capping it to the maximum hardware watermark or adjust it to a value that is supported by the hardware). It can also disable the hardware watermark (and implicitly the hardware FIFO) it this value is below the minimum hardware watermark. Since a driver may support hardware FIFO only when not in triggered buffer mode (due to different semantics of hardware FIFO sampling and triggered sampling) this patch changes the IIO core code to allow falling back to non-triggered buffered mode if no trigger is enabled. 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>
2015-03-29iio: add watermark logic to iio read and pollJosselin Costanzi
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>
2015-02-04iio: buffer: refactor buffer attributes setupOctavian Purdila
Move all core (non-custom) buffer attributes to a vector to make it easier to add more of them in the future. Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-01-25iio: Add new operating mode for non triggered sw buffersKarol Wrona
There was a need for non triggered software buffer type. It can be used when triggered model does not fit and INDIO_BUFFER_HARDWARE causes confusion because the data stream can be obtained not directly form hardware backend. Suggested-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Karol Wrona <k.wrona@samsung.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-01-05iio: buffer: fix custom buffer attributes copyOctavian Purdila
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 Clausen
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: Make length attribute read only for buffers without set_lengthLars-Peter Clausen
If a buffer implementation does not implement the set_length() callback the length will be static and can not be changed by userspace. Mark the length attribute as a read only property in this case so userspace is aware of this rather than just silently accepting any length value. 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 Clausen
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: buffer: Move iio_buffer_alloc_sysfs and iio_buffer_free_sysfsLars-Peter Clausen
The next patch will introduce new dependencies in iio_buffer_alloc_sysfs() to functions which are currently defined after iio_buffer_alloc_sysfs(). To avoid forward declarations move both iio_buffer_alloc_sysfs() and iio_buffer_free_sysfs() after those function. This is split into two patches one moving the functions and one adding the dependencies to make review of the actual changes easier. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>