| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jonathan Cameron | 3047 | 28.44% | 45 | 24.86% |
| Lars-Peter Clausen | 2089 | 19.50% | 51 | 28.18% |
| Paul Cercueil | 2008 | 18.75% | 1 | 0.55% |
| Alexandru Ardelean | 1927 | 17.99% | 18 | 9.94% |
| Mihail Chindris | 328 | 3.06% | 1 | 0.55% |
| David Lechner | 307 | 2.87% | 3 | 1.66% |
| Josselin Costanzi | 174 | 1.62% | 1 | 0.55% |
| Octavian Purdila | 162 | 1.51% | 3 | 1.66% |
| Nuno Sá | 132 | 1.23% | 6 | 3.31% |
| Brian Norris | 102 | 0.95% | 1 | 0.55% |
| Matti Vaittinen | 47 | 0.44% | 2 | 1.10% |
| Yang Yingliang | 44 | 0.41% | 4 | 2.21% |
| Srinivas Pandruvada | 34 | 0.32% | 1 | 0.55% |
| Matt Fornero | 32 | 0.30% | 1 | 0.55% |
| Lars Möllendorf | 31 | 0.29% | 1 | 0.55% |
| Michael Hennerich | 26 | 0.24% | 4 | 2.21% |
| Christophe Jaillet | 25 | 0.23% | 3 | 1.66% |
| Jakob Koschel | 25 | 0.23% | 1 | 0.55% |
| Marek Vašut | 20 | 0.19% | 1 | 0.55% |
| Andy Shevchenko | 20 | 0.19% | 2 | 1.10% |
| Joe Simmons-Talbott | 18 | 0.17% | 2 | 1.10% |
| Manuel Stahl | 17 | 0.16% | 1 | 0.55% |
| Barry Song | 10 | 0.09% | 2 | 1.10% |
| Hartmut Knaack | 9 | 0.08% | 1 | 0.55% |
| Peter Meerwald-Stadler | 8 | 0.07% | 2 | 1.10% |
| Irina Tirdea | 7 | 0.07% | 1 | 0.55% |
| Miquel Raynal | 6 | 0.06% | 1 | 0.55% |
| Greg Kroah-Hartman | 6 | 0.06% | 2 | 1.10% |
| Alec Berg | 6 | 0.06% | 1 | 0.55% |
| Song Qiang | 6 | 0.06% | 1 | 0.55% |
| Michał Mirosław | 6 | 0.06% | 1 | 0.55% |
| Linus Torvalds | 6 | 0.06% | 2 | 1.10% |
| Colin Ian King | 4 | 0.04% | 2 | 1.10% |
| Sachin Kamat | 4 | 0.04% | 1 | 0.55% |
| Mathias Krause | 3 | 0.03% | 1 | 0.55% |
| Paul Gortmaker | 3 | 0.03% | 1 | 0.55% |
| Thomas Meyer | 2 | 0.02% | 1 | 0.55% |
| Stefan Windfeldt-Prytz | 2 | 0.02% | 1 | 0.55% |
| Linus Torvalds (pre-git) | 2 | 0.02% | 1 | 0.55% |
| Cristina Opriceana | 2 | 0.02% | 2 | 1.10% |
| Thomas Gleixner | 2 | 0.02% | 1 | 0.55% |
| Ingo Molnar | 1 | 0.01% | 1 | 0.55% |
| Al Viro | 1 | 0.01% | 1 | 0.55% |
| SF Markus Elfring | 1 | 0.01% | 1 | 0.55% |
| Total | 10712 | 181 |
// SPDX-License-Identifier: GPL-2.0-only /* The industrial I/O core * * Copyright (c) 2008 Jonathan Cameron * * Handling of buffer allocation / resizing. * * Things to look at here. * - Better memory allocation techniques? * - Alternative access techniques? */ #include <linux/atomic.h> #include <linux/anon_inodes.h> #include <linux/cleanup.h> #include <linux/kernel.h> #include <linux/export.h> #include <linux/device.h> #include <linux/dma-buf.h> #include <linux/dma-fence.h> #include <linux/dma-resv.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/cdev.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/poll.h> #include <linux/sched/signal.h> #include <linux/iio/iio.h> #include <linux/iio/iio-opaque.h> #include "iio_core.h" #include "iio_core_trigger.h" #include <linux/iio/sysfs.h> #include <linux/iio/buffer.h> #include <linux/iio/buffer_impl.h> #define DMABUF_ENQUEUE_TIMEOUT_MS 5000 MODULE_IMPORT_NS(DMA_BUF); struct iio_dmabuf_priv { struct list_head entry; struct kref ref; struct iio_buffer *buffer; struct iio_dma_buffer_block *block; u64 context; /* Spinlock used for locking the dma_fence */ spinlock_t lock; struct dma_buf_attachment *attach; struct sg_table *sgt; enum dma_data_direction dir; atomic_t seqno; }; struct iio_dma_fence { struct dma_fence base; struct iio_dmabuf_priv *priv; struct work_struct work; }; static const char * const iio_endian_prefix[] = { [IIO_BE] = "be", [IIO_LE] = "le", }; static bool iio_buffer_is_active(struct iio_buffer *buf) { return !list_empty(&buf->buffer_list); } static size_t iio_buffer_data_available(struct iio_buffer *buf) { return buf->access->data_available(buf); } static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev, struct iio_buffer *buf, size_t required) { if (!indio_dev->info->hwfifo_flush_to_buffer) return -ENODEV; return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required); } static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf, size_t to_wait, int to_flush) { size_t avail; int flushed = 0; /* wakeup if the device was unregistered */ if (!indio_dev->info) return true; /* drain the buffer if it was disabled */ if (!iio_buffer_is_active(buf)) { to_wait = min_t(size_t, to_wait, 1); to_flush = 0; } avail = iio_buffer_data_available(buf); if (avail >= to_wait) { /* force a flush for non-blocking reads */ if (!to_wait && avail < to_flush) iio_buffer_flush_hwfifo(indio_dev, buf, to_flush - avail); return true; } if (to_flush) flushed = iio_buffer_flush_hwfifo(indio_dev, buf, to_wait - avail); if (flushed <= 0) return false; if (avail + flushed >= to_wait) return true; return false; } /** * iio_buffer_read() - chrdev read for buffer access * @filp: File structure pointer for the char device * @buf: Destination buffer for iio buffer read * @n: First n bytes to read * @f_ps: Long offset provided by the user as a seek position * * This function relies on all buffer implementations having an * iio_buffer as their first element. * * Return: negative values corresponding to error codes or ret != 0 * for ending the reading activity **/ static ssize_t iio_buffer_read(struct file *filp, char __user *buf, size_t n, loff_t *f_ps) { struct iio_dev_buffer_pair *ib = filp->private_data; struct iio_buffer *rb = ib->buffer; struct iio_dev *indio_dev = ib->indio_dev; DEFINE_WAIT_FUNC(wait, woken_wake_function); size_t datum_size; size_t to_wait; int ret = 0; if (!indio_dev->info) return -ENODEV; if (!rb || !rb->access->read) return -EINVAL; if (rb->direction != IIO_BUFFER_DIRECTION_IN) return -EPERM; datum_size = rb->bytes_per_datum; /* * If datum_size is 0 there will never be anything to read from the * buffer, so signal end of file now. */ if (!datum_size) return 0; if (filp->f_flags & O_NONBLOCK) to_wait = 0; else to_wait = min_t(size_t, n / datum_size, rb->watermark); add_wait_queue(&rb->pollq, &wait); do { if (!indio_dev->info) { ret = -ENODEV; break; } if (!iio_buffer_ready(indio_dev, rb, to_wait, n / datum_size)) { if (signal_pending(current)) { ret = -ERESTARTSYS; break; } wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); continue; } ret = rb->access->read(rb, n, buf); if (ret == 0 && (filp->f_flags & O_NONBLOCK)) ret = -EAGAIN; } while (ret == 0); remove_wait_queue(&rb->pollq, &wait); return ret; } static size_t iio_buffer_space_available(struct iio_buffer *buf) { if (buf->access->space_available) return buf->access->space_available(buf); return SIZE_MAX; } static ssize_t iio_buffer_write(struct file *filp, const char __user *buf, size_t n, loff_t *f_ps) { struct iio_dev_buffer_pair *ib = filp->private_data; struct iio_buffer *rb = ib->buffer; struct iio_dev *indio_dev = ib->indio_dev; DEFINE_WAIT_FUNC(wait, woken_wake_function); int ret = 0; size_t written; if (!indio_dev->info) return -ENODEV; if (!rb || !rb->access->write) return -EINVAL; if (rb->direction != IIO_BUFFER_DIRECTION_OUT) return -EPERM; written = 0; add_wait_queue(&rb->pollq, &wait); do { if (!indio_dev->info) return -ENODEV; if (!iio_buffer_space_available(rb)) { if (signal_pending(current)) { ret = -ERESTARTSYS; break; } if (filp->f_flags & O_NONBLOCK) { if (!written) ret = -EAGAIN; break; } wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); continue; } ret = rb->access->write(rb, n - written, buf + written); if (ret < 0) break; written += ret; } while (written != n); remove_wait_queue(&rb->pollq, &wait); return ret < 0 ? ret : written; } /** * iio_buffer_poll() - poll the buffer to find out if it has data * @filp: File structure pointer for device access * @wait: Poll table structure pointer for which the driver adds * a wait queue * * Return: (EPOLLIN | EPOLLRDNORM) if data is available for reading * or 0 for other cases */ static __poll_t iio_buffer_poll(struct file *filp, struct poll_table_struct *wait) { struct iio_dev_buffer_pair *ib = filp->private_data; struct iio_buffer *rb = ib->buffer; struct iio_dev *indio_dev = ib->indio_dev; if (!indio_dev->info || !rb) return 0; poll_wait(filp, &rb->pollq, wait); switch (rb->direction) { case IIO_BUFFER_DIRECTION_IN: if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0)) return EPOLLIN | EPOLLRDNORM; break; case IIO_BUFFER_DIRECTION_OUT: if (iio_buffer_space_available(rb)) return EPOLLOUT | EPOLLWRNORM; break; } return 0; } ssize_t iio_buffer_read_wrapper(struct file *filp, char __user *buf, size_t n, loff_t *f_ps) { struct iio_dev_buffer_pair *ib = filp->private_data; struct iio_buffer *rb = ib->buffer; /* check if buffer was opened through new API */ if (test_bit(IIO_BUSY_BIT_POS, &rb->flags)) return -EBUSY; return iio_buffer_read(filp, buf, n, f_ps); } ssize_t iio_buffer_write_wrapper(struct file *filp, const char __user *buf, size_t n, loff_t *f_ps) { struct iio_dev_buffer_pair *ib = filp->private_data; struct iio_buffer *rb = ib->buffer; /* check if buffer was opened through new API */ if (test_bit(IIO_BUSY_BIT_POS, &rb->flags)) return -EBUSY; return iio_buffer_write(filp, buf, n, f_ps); } __poll_t iio_buffer_poll_wrapper(struct file *filp, struct poll_table_struct *wait) { struct iio_dev_buffer_pair *ib = filp->private_data; struct iio_buffer *rb = ib->buffer; /* check if buffer was opened through new API */ if (test_bit(IIO_BUSY_BIT_POS, &rb->flags)) return 0; return iio_buffer_poll(filp, wait); } /** * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue * @indio_dev: The IIO device * * Wakes up the event waitqueue used for poll(). Should usually * be called when the device is unregistered. */ void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer; unsigned int i; for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { buffer = iio_dev_opaque->attached_buffers[i]; wake_up(&buffer->pollq); } } int iio_pop_from_buffer(struct iio_buffer *buffer, void *data) { if (!buffer || !buffer->access || !buffer->access->remove_from) return -EINVAL; return buffer->access->remove_from(buffer, data); } EXPORT_SYMBOL_GPL(iio_pop_from_buffer); void iio_buffer_init(struct iio_buffer *buffer) { INIT_LIST_HEAD(&buffer->demux_list); INIT_LIST_HEAD(&buffer->buffer_list); INIT_LIST_HEAD(&buffer->dmabufs); mutex_init(&buffer->dmabufs_mutex); init_waitqueue_head(&buffer->pollq); kref_init(&buffer->ref); if (!buffer->watermark) buffer->watermark = 1; } EXPORT_SYMBOL(iio_buffer_init); void iio_device_detach_buffers(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer; unsigned int i; for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { buffer = iio_dev_opaque->attached_buffers[i]; iio_buffer_put(buffer); } kfree(iio_dev_opaque->attached_buffers); } static ssize_t iio_show_scan_index(struct device *dev, struct device_attribute *attr, char *buf) { return sysfs_emit(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index); } static ssize_t iio_show_fixed_type(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); const struct iio_scan_type *scan_type; u8 type; scan_type = iio_get_current_scan_type(indio_dev, this_attr->c); if (IS_ERR(scan_type)) return PTR_ERR(scan_type); type = scan_type->endianness; if (type == IIO_CPU) { #ifdef __LITTLE_ENDIAN type = IIO_LE; #else type = IIO_BE; #endif } if (scan_type->repeat > 1) return sysfs_emit(buf, "%s:%c%d/%dX%d>>%u\n", iio_endian_prefix[type], scan_type->sign, scan_type->realbits, scan_type->storagebits, scan_type->repeat, scan_type->shift); else return sysfs_emit(buf, "%s:%c%d/%d>>%u\n", iio_endian_prefix[type], scan_type->sign, scan_type->realbits, scan_type->storagebits, scan_type->shift); } static ssize_t iio_scan_el_show(struct device *dev, struct device_attribute *attr, char *buf) { int ret; struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; /* Ensure ret is 0 or 1. */ ret = !!test_bit(to_iio_dev_attr(attr)->address, buffer->scan_mask); return sysfs_emit(buf, "%d\n", ret); } /* Note NULL used as error indicator as it doesn't make sense. */ static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks, unsigned int masklength, const unsigned long *mask, bool strict) { if (bitmap_empty(mask, masklength)) return NULL; /* * The condition here do not handle multi-long masks correctly. * It only checks the first long to be zero, and will use such mask * as a terminator even if there was bits set after the first long. * * Correct check would require using: * while (!bitmap_empty(av_masks, masklength)) * instead. This is potentially hazardous because the * avaliable_scan_masks is a zero terminated array of longs - and * using the proper bitmap_empty() check for multi-long wide masks * would require the array to be terminated with multiple zero longs - * which is not such an usual pattern. * * As writing of this no multi-long wide masks were found in-tree, so * the simple while (*av_masks) check is working. */ while (*av_masks) { if (strict) { if (bitmap_equal(mask, av_masks, masklength)) return av_masks; } else { if (bitmap_subset(mask, av_masks, masklength)) return av_masks; } av_masks += BITS_TO_LONGS(masklength); } return NULL; } static bool iio_validate_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask) { if (!indio_dev->setup_ops->validate_scan_mask) return true; return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask); } /** * iio_scan_mask_set() - set particular bit in the scan mask * @indio_dev: the iio device * @buffer: the buffer whose scan mask we are interested in * @bit: the bit to be set. * * Note that at this point we have no way of knowing what other * buffers might request, hence this code only verifies that the * individual buffers request is plausible. */ static int iio_scan_mask_set(struct iio_dev *indio_dev, struct iio_buffer *buffer, int bit) { const unsigned long *mask; unsigned long *trialmask; if (!indio_dev->masklength) { WARN(1, "Trying to set scanmask prior to registering buffer\n"); return -EINVAL; } trialmask = bitmap_alloc(indio_dev->masklength, GFP_KERNEL); if (!trialmask) return -ENOMEM; bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength); set_bit(bit, trialmask); if (!iio_validate_scan_mask(indio_dev, trialmask)) goto err_invalid_mask; if (indio_dev->available_scan_masks) { mask = iio_scan_mask_match(indio_dev->available_scan_masks, indio_dev->masklength, trialmask, false); if (!mask) goto err_invalid_mask; } bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength); bitmap_free(trialmask); return 0; err_invalid_mask: bitmap_free(trialmask); return -EINVAL; } static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit) { clear_bit(bit, buffer->scan_mask); return 0; } static int iio_scan_mask_query(struct iio_dev *indio_dev, struct iio_buffer *buffer, int bit) { if (bit > indio_dev->masklength) return -EINVAL; if (!buffer->scan_mask) return 0; /* Ensure return value is 0 or 1. */ return !!test_bit(bit, buffer->scan_mask); }; static ssize_t iio_scan_el_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { int ret; bool state; struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); struct iio_buffer *buffer = this_attr->buffer; ret = kstrtobool(buf, &state); if (ret < 0) return ret; guard(mutex)(&iio_dev_opaque->mlock); if (iio_buffer_is_active(buffer)) return -EBUSY; ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address); if (ret < 0) return ret; if (state && ret) return len; if (state) ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address); else ret = iio_scan_mask_clear(buffer, this_attr->address); if (ret) return ret; return len; } static ssize_t iio_scan_el_ts_show(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; return sysfs_emit(buf, "%d\n", buffer->scan_timestamp); } static ssize_t iio_scan_el_ts_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { int ret; struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; bool state; ret = kstrtobool(buf, &state); if (ret < 0) return ret; guard(mutex)(&iio_dev_opaque->mlock); if (iio_buffer_is_active(buffer)) return -EBUSY; buffer->scan_timestamp = state; return len; } static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev, struct iio_buffer *buffer, const struct iio_chan_spec *chan) { int ret, attrcount = 0; ret = __iio_add_chan_devattr("index", chan, &iio_show_scan_index, NULL, 0, IIO_SEPARATE, &indio_dev->dev, buffer, &buffer->buffer_attr_list); if (ret) return ret; attrcount++; ret = __iio_add_chan_devattr("type", chan, &iio_show_fixed_type, NULL, 0, IIO_SEPARATE, &indio_dev->dev, buffer, &buffer->buffer_attr_list); if (ret) return ret; attrcount++; if (chan->type != IIO_TIMESTAMP) ret = __iio_add_chan_devattr("en", chan, &iio_scan_el_show, &iio_scan_el_store, chan->scan_index, IIO_SEPARATE, &indio_dev->dev, buffer, &buffer->buffer_attr_list); else ret = __iio_add_chan_devattr("en", chan, &iio_scan_el_ts_show, &iio_scan_el_ts_store, chan->scan_index, IIO_SEPARATE, &indio_dev->dev, buffer, &buffer->buffer_attr_list); if (ret) return ret; attrcount++; ret = attrcount; return ret; } static ssize_t length_show(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; return sysfs_emit(buf, "%d\n", buffer->length); } static ssize_t length_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; unsigned int val; int ret; ret = kstrtouint(buf, 10, &val); if (ret) return ret; if (val == buffer->length) return len; guard(mutex)(&iio_dev_opaque->mlock); if (iio_buffer_is_active(buffer)) return -EBUSY; buffer->access->set_length(buffer, val); if (buffer->length && buffer->length < buffer->watermark) buffer->watermark = buffer->length; return len; } static ssize_t enable_show(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; return sysfs_emit(buf, "%d\n", iio_buffer_is_active(buffer)); } static int iio_storage_bytes_for_si(struct iio_dev *indio_dev, unsigned int scan_index) { const struct iio_chan_spec *ch; const struct iio_scan_type *scan_type; unsigned int bytes; ch = iio_find_channel_from_si(indio_dev, scan_index); scan_type = iio_get_current_scan_type(indio_dev, ch); if (IS_ERR(scan_type)) return PTR_ERR(scan_type); bytes = scan_type->storagebits / 8; if (scan_type->repeat > 1) bytes *= scan_type->repeat; return bytes; } static int iio_storage_bytes_for_timestamp(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); return iio_storage_bytes_for_si(indio_dev, iio_dev_opaque->scan_index_timestamp); } static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const unsigned long *mask, bool timestamp) { unsigned int bytes = 0; int length, i, largest = 0; /* How much space will the demuxed element take? */ for_each_set_bit(i, mask, indio_dev->masklength) { length = iio_storage_bytes_for_si(indio_dev, i); if (length < 0) return length; bytes = ALIGN(bytes, length); bytes += length; largest = max(largest, length); } if (timestamp) { length = iio_storage_bytes_for_timestamp(indio_dev); if (length < 0) return length; bytes = ALIGN(bytes, length); bytes += length; largest = max(largest, length); } bytes = ALIGN(bytes, largest); return bytes; } static void iio_buffer_activate(struct iio_dev *indio_dev, struct iio_buffer *buffer) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); iio_buffer_get(buffer); list_add(&buffer->buffer_list, &iio_dev_opaque->buffer_list); } static void iio_buffer_deactivate(struct iio_buffer *buffer) { list_del_init(&buffer->buffer_list); wake_up_interruptible(&buffer->pollq); iio_buffer_put(buffer); } static void iio_buffer_deactivate_all(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer, *_buffer; list_for_each_entry_safe(buffer, _buffer, &iio_dev_opaque->buffer_list, buffer_list) iio_buffer_deactivate(buffer); } static int iio_buffer_enable(struct iio_buffer *buffer, struct iio_dev *indio_dev) { if (!buffer->access->enable) return 0; return buffer->access->enable(buffer, indio_dev); } static int iio_buffer_disable(struct iio_buffer *buffer, struct iio_dev *indio_dev) { if (!buffer->access->disable) return 0; return buffer->access->disable(buffer, indio_dev); } static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev, struct iio_buffer *buffer) { unsigned int bytes; if (!buffer->access->set_bytes_per_datum) return; bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask, buffer->scan_timestamp); buffer->access->set_bytes_per_datum(buffer, bytes); } static int iio_buffer_request_update(struct iio_dev *indio_dev, struct iio_buffer *buffer) { int ret; iio_buffer_update_bytes_per_datum(indio_dev, buffer); if (buffer->access->request_update) { ret = buffer->access->request_update(buffer); if (ret) { dev_dbg(&indio_dev->dev, "Buffer not started: buffer parameter update failed (%d)\n", ret); return ret; } } return 0; } static void iio_free_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask) { /* If the mask is dynamically allocated free it, otherwise do nothing */ if (!indio_dev->available_scan_masks) bitmap_free(mask); } struct iio_device_config { unsigned int mode; unsigned int watermark; const unsigned long *scan_mask; unsigned int scan_bytes; bool scan_timestamp; }; static int iio_verify_update(struct iio_dev *indio_dev, struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer, struct iio_device_config *config) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); unsigned long *compound_mask; const unsigned long *scan_mask; bool strict_scanmask = false; struct iio_buffer *buffer; bool scan_timestamp; unsigned int modes; if (insert_buffer && bitmap_empty(insert_buffer->scan_mask, indio_dev->masklength)) { dev_dbg(&indio_dev->dev, "At least one scan element must be enabled first\n"); return -EINVAL; } memset(config, 0, sizeof(*config)); config->watermark = ~0; /* * If there is just one buffer and we are removing it there is nothing * to verify. */ if (remove_buffer && !insert_buffer && list_is_singular(&iio_dev_opaque->buffer_list)) return 0; modes = indio_dev->modes; list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) { if (buffer == remove_buffer) continue; modes &= buffer->access->modes; config->watermark = min(config->watermark, buffer->watermark); } if (insert_buffer) { modes &= insert_buffer->access->modes; config->watermark = min(config->watermark, insert_buffer->watermark); } /* Definitely possible for devices to support both of these. */ if ((modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) { config->mode = INDIO_BUFFER_TRIGGERED; } else if (modes & INDIO_BUFFER_HARDWARE) { /* * Keep things simple for now and only allow a single buffer to * be connected in hardware mode. */ if (insert_buffer && !list_empty(&iio_dev_opaque->buffer_list)) return -EINVAL; config->mode = INDIO_BUFFER_HARDWARE; strict_scanmask = true; } else if (modes & INDIO_BUFFER_SOFTWARE) { config->mode = INDIO_BUFFER_SOFTWARE; } else { /* Can only occur on first buffer */ if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) dev_dbg(&indio_dev->dev, "Buffer not started: no trigger\n"); return -EINVAL; } /* What scan mask do we actually have? */ compound_mask = bitmap_zalloc(indio_dev->masklength, GFP_KERNEL); if (!compound_mask) return -ENOMEM; scan_timestamp = false; list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) { if (buffer == remove_buffer) continue; bitmap_or(compound_mask, compound_mask, buffer->scan_mask, indio_dev->masklength); scan_timestamp |= buffer->scan_timestamp; } if (insert_buffer) { bitmap_or(compound_mask, compound_mask, insert_buffer->scan_mask, indio_dev->masklength); scan_timestamp |= insert_buffer->scan_timestamp; } if (indio_dev->available_scan_masks) { scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks, indio_dev->masklength, compound_mask, strict_scanmask); bitmap_free(compound_mask); if (!scan_mask) return -EINVAL; } else { scan_mask = compound_mask; } config->scan_bytes = iio_compute_scan_bytes(indio_dev, scan_mask, scan_timestamp); config->scan_mask = scan_mask; config->scan_timestamp = scan_timestamp; return 0; } /** * struct iio_demux_table - table describing demux memcpy ops * @from: index to copy from * @to: index to copy to * @length: how many bytes to copy * @l: list head used for management */ struct iio_demux_table { unsigned int from; unsigned int to; unsigned int length; struct list_head l; }; static void iio_buffer_demux_free(struct iio_buffer *buffer) { struct iio_demux_table *p, *q; list_for_each_entry_safe(p, q, &buffer->demux_list, l) { list_del(&p->l); kfree(p); } } static int iio_buffer_add_demux(struct iio_buffer *buffer, struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc, unsigned int length) { if (*p && (*p)->from + (*p)->length == in_loc && (*p)->to + (*p)->length == out_loc) { (*p)->length += length; } else { *p = kmalloc(sizeof(**p), GFP_KERNEL); if (!(*p)) return -ENOMEM; (*p)->from = in_loc; (*p)->to = out_loc; (*p)->length = length; list_add_tail(&(*p)->l, &buffer->demux_list); } return 0; } static int iio_buffer_update_demux(struct iio_dev *indio_dev, struct iio_buffer *buffer) { int ret, in_ind = -1, out_ind, length; unsigned int in_loc = 0, out_loc = 0; struct iio_demux_table *p = NULL; /* Clear out any old demux */ iio_buffer_demux_free(buffer); kfree(buffer->demux_bounce); buffer->demux_bounce = NULL; /* First work out which scan mode we will actually have */ if (bitmap_equal(indio_dev->active_scan_mask, buffer->scan_mask, indio_dev->masklength)) return 0; /* Now we have the two masks, work from least sig and build up sizes */ for_each_set_bit(out_ind, buffer->scan_mask, indio_dev->masklength) { in_ind = find_next_bit(indio_dev->active_scan_mask, indio_dev->masklength, in_ind + 1); while (in_ind != out_ind) { ret = iio_storage_bytes_for_si(indio_dev, in_ind); if (ret < 0) goto error_clear_mux_table; length = ret; /* Make sure we are aligned */ in_loc = roundup(in_loc, length) + length; in_ind = find_next_bit(indio_dev->active_scan_mask, indio_dev->masklength, in_ind + 1); } ret = iio_storage_bytes_for_si(indio_dev, in_ind); if (ret < 0) goto error_clear_mux_table; length = ret; out_loc = roundup(out_loc, length); in_loc = roundup(in_loc, length); ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length); if (ret) goto error_clear_mux_table; out_loc += length; in_loc += length; } /* Relies on scan_timestamp being last */ if (buffer->scan_timestamp) { ret = iio_storage_bytes_for_timestamp(indio_dev); if (ret < 0) goto error_clear_mux_table; length = ret; out_loc = roundup(out_loc, length); in_loc = roundup(in_loc, length); ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length); if (ret) goto error_clear_mux_table; out_loc += length; } buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL); if (!buffer->demux_bounce) { ret = -ENOMEM; goto error_clear_mux_table; } return 0; error_clear_mux_table: iio_buffer_demux_free(buffer); return ret; } static int iio_update_demux(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer; int ret; list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) { ret = iio_buffer_update_demux(indio_dev, buffer); if (ret < 0) goto error_clear_mux_table; } return 0; error_clear_mux_table: list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) iio_buffer_demux_free(buffer); return ret; } static int iio_enable_buffers(struct iio_dev *indio_dev, struct iio_device_config *config) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer, *tmp = NULL; int ret; indio_dev->active_scan_mask = config->scan_mask; indio_dev->scan_timestamp = config->scan_timestamp; indio_dev->scan_bytes = config->scan_bytes; iio_dev_opaque->currentmode = config->mode; iio_update_demux(indio_dev); /* Wind up again */ if (indio_dev->setup_ops->preenable) { ret = indio_dev->setup_ops->preenable(indio_dev); if (ret) { dev_dbg(&indio_dev->dev, "Buffer not started: buffer preenable failed (%d)\n", ret); goto err_undo_config; } } if (indio_dev->info->update_scan_mode) { ret = indio_dev->info ->update_scan_mode(indio_dev, indio_dev->active_scan_mask); if (ret < 0) { dev_dbg(&indio_dev->dev, "Buffer not started: update scan mode failed (%d)\n", ret); goto err_run_postdisable; } } if (indio_dev->info->hwfifo_set_watermark) indio_dev->info->hwfifo_set_watermark(indio_dev, config->watermark); list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) { ret = iio_buffer_enable(buffer, indio_dev); if (ret) { tmp = buffer; goto err_disable_buffers; } } if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) { ret = iio_trigger_attach_poll_func(indio_dev->trig, indio_dev->pollfunc); if (ret) goto err_disable_buffers; } if (indio_dev->setup_ops->postenable) { ret = indio_dev->setup_ops->postenable(indio_dev); if (ret) { dev_dbg(&indio_dev->dev, "Buffer not started: postenable failed (%d)\n", ret); goto err_detach_pollfunc; } } return 0; err_detach_pollfunc: if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) { iio_trigger_detach_poll_func(indio_dev->trig, indio_dev->pollfunc); } err_disable_buffers: buffer = list_prepare_entry(tmp, &iio_dev_opaque->buffer_list, buffer_list); list_for_each_entry_continue_reverse(buffer, &iio_dev_opaque->buffer_list, buffer_list) iio_buffer_disable(buffer, indio_dev); err_run_postdisable: if (indio_dev->setup_ops->postdisable) indio_dev->setup_ops->postdisable(indio_dev); err_undo_config: iio_dev_opaque->currentmode = INDIO_DIRECT_MODE; indio_dev->active_scan_mask = NULL; return ret; } static int iio_disable_buffers(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer; int ret = 0; int ret2; /* Wind down existing buffers - iff there are any */ if (list_empty(&iio_dev_opaque->buffer_list)) return 0; /* * If things go wrong at some step in disable we still need to continue * to perform the other steps, otherwise we leave the device in a * inconsistent state. We return the error code for the first error we * encountered. */ if (indio_dev->setup_ops->predisable) { ret2 = indio_dev->setup_ops->predisable(indio_dev); if (ret2 && !ret) ret = ret2; } if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) { iio_trigger_detach_poll_func(indio_dev->trig, indio_dev->pollfunc); } list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) { ret2 = iio_buffer_disable(buffer, indio_dev); if (ret2 && !ret) ret = ret2; } if (indio_dev->setup_ops->postdisable) { ret2 = indio_dev->setup_ops->postdisable(indio_dev); if (ret2 && !ret) ret = ret2; } iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask); indio_dev->active_scan_mask = NULL; iio_dev_opaque->currentmode = INDIO_DIRECT_MODE; return ret; } static int __iio_update_buffers(struct iio_dev *indio_dev, struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_device_config new_config; int ret; ret = iio_verify_update(indio_dev, insert_buffer, remove_buffer, &new_config); if (ret) return ret; if (insert_buffer) { ret = iio_buffer_request_update(indio_dev, insert_buffer); if (ret) goto err_free_config; } ret = iio_disable_buffers(indio_dev); if (ret) goto err_deactivate_all; if (remove_buffer) iio_buffer_deactivate(remove_buffer); if (insert_buffer) iio_buffer_activate(indio_dev, insert_buffer); /* If no buffers in list, we are done */ if (list_empty(&iio_dev_opaque->buffer_list)) return 0; ret = iio_enable_buffers(indio_dev, &new_config); if (ret) goto err_deactivate_all; return 0; err_deactivate_all: /* * We've already verified that the config is valid earlier. If things go * wrong in either enable or disable the most likely reason is an IO * error from the device. In this case there is no good recovery * strategy. Just make sure to disable everything and leave the device * in a sane state. With a bit of luck the device might come back to * life again later and userspace can try again. */ iio_buffer_deactivate_all(indio_dev); err_free_config: iio_free_scan_mask(indio_dev, new_config.scan_mask); return ret; } int iio_update_buffers(struct iio_dev *indio_dev, struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); if (insert_buffer == remove_buffer) return 0; if (insert_buffer && insert_buffer->direction == IIO_BUFFER_DIRECTION_OUT) return -EINVAL; guard(mutex)(&iio_dev_opaque->info_exist_lock); guard(mutex)(&iio_dev_opaque->mlock); if (insert_buffer && iio_buffer_is_active(insert_buffer)) insert_buffer = NULL; if (remove_buffer && !iio_buffer_is_active(remove_buffer)) remove_buffer = NULL; if (!insert_buffer && !remove_buffer) return 0; if (!indio_dev->info) return -ENODEV; return __iio_update_buffers(indio_dev, insert_buffer, remove_buffer); } EXPORT_SYMBOL_GPL(iio_update_buffers); void iio_disable_all_buffers(struct iio_dev *indio_dev) { iio_disable_buffers(indio_dev); iio_buffer_deactivate_all(indio_dev); } static ssize_t enable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { int ret; bool requested_state; struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; bool inlist; ret = kstrtobool(buf, &requested_state); if (ret < 0) return ret; guard(mutex)(&iio_dev_opaque->mlock); /* Find out if it is in the list */ inlist = iio_buffer_is_active(buffer); /* Already in desired state */ if (inlist == requested_state) return len; if (requested_state) ret = __iio_update_buffers(indio_dev, buffer, NULL); else ret = __iio_update_buffers(indio_dev, NULL, buffer); if (ret) return ret; return len; } static ssize_t watermark_show(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; return sysfs_emit(buf, "%u\n", buffer->watermark); } static ssize_t watermark_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; unsigned int val; int ret; ret = kstrtouint(buf, 10, &val); if (ret) return ret; if (!val) return -EINVAL; guard(mutex)(&iio_dev_opaque->mlock); if (val > buffer->length) return -EINVAL; if (iio_buffer_is_active(buffer)) return -EBUSY; buffer->watermark = val; return len; } static ssize_t data_available_show(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; return sysfs_emit(buf, "%zu\n", iio_buffer_data_available(buffer)); } static ssize_t direction_show(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; switch (buffer->direction) { case IIO_BUFFER_DIRECTION_IN: return sysfs_emit(buf, "in\n"); case IIO_BUFFER_DIRECTION_OUT: return sysfs_emit(buf, "out\n"); default: return -EINVAL; } } static DEVICE_ATTR_RW(length); static struct device_attribute dev_attr_length_ro = __ATTR_RO(length); static DEVICE_ATTR_RW(enable); static DEVICE_ATTR_RW(watermark); static struct device_attribute dev_attr_watermark_ro = __ATTR_RO(watermark); static DEVICE_ATTR_RO(data_available); static DEVICE_ATTR_RO(direction); /* * When adding new attributes here, put the at the end, at least until * the code that handles the length/length_ro & watermark/watermark_ro * assignments gets cleaned up. Otherwise these can create some weird * duplicate attributes errors under some setups. */ static struct attribute *iio_buffer_attrs[] = { &dev_attr_length.attr, &dev_attr_enable.attr, &dev_attr_watermark.attr, &dev_attr_data_available.attr, &dev_attr_direction.attr, }; #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer, struct attribute *attr) { struct device_attribute *dattr = to_dev_attr(attr); struct iio_dev_attr *iio_attr; iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL); if (!iio_attr) return NULL; iio_attr->buffer = buffer; memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr)); iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL); if (!iio_attr->dev_attr.attr.name) { kfree(iio_attr); return NULL; } sysfs_attr_init(&iio_attr->dev_attr.attr); list_add(&iio_attr->l, &buffer->buffer_attr_list); return &iio_attr->dev_attr.attr; } static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev, struct attribute **buffer_attrs, int buffer_attrcount, int scan_el_attrcount) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct attribute_group *group; struct attribute **attrs; int ret; attrs = kcalloc(buffer_attrcount + 1, sizeof(*attrs), GFP_KERNEL); if (!attrs) return -ENOMEM; memcpy(attrs, buffer_attrs, buffer_attrcount * sizeof(*attrs)); group = &iio_dev_opaque->legacy_buffer_group; group->attrs = attrs; group->name = "buffer"; ret = iio_device_register_sysfs_group(indio_dev, group); if (ret) goto error_free_buffer_attrs; attrs = kcalloc(scan_el_attrcount + 1, sizeof(*attrs), GFP_KERNEL); if (!attrs) { ret = -ENOMEM; goto error_free_buffer_attrs; } memcpy(attrs, &buffer_attrs[buffer_attrcount], scan_el_attrcount * sizeof(*attrs)); group = &iio_dev_opaque->legacy_scan_el_group; group->attrs = attrs; group->name = "scan_elements"; ret = iio_device_register_sysfs_group(indio_dev, group); if (ret) goto error_free_scan_el_attrs; return 0; error_free_scan_el_attrs: kfree(iio_dev_opaque->legacy_scan_el_group.attrs); error_free_buffer_attrs: kfree(iio_dev_opaque->legacy_buffer_group.attrs); return ret; } static void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); kfree(iio_dev_opaque->legacy_buffer_group.attrs); kfree(iio_dev_opaque->legacy_scan_el_group.attrs); } static void iio_buffer_dmabuf_release(struct kref *ref) { struct iio_dmabuf_priv *priv = container_of(ref, struct iio_dmabuf_priv, ref); struct dma_buf_attachment *attach = priv->attach; struct iio_buffer *buffer = priv->buffer; struct dma_buf *dmabuf = attach->dmabuf; dma_resv_lock(dmabuf->resv, NULL); dma_buf_unmap_attachment(attach, priv->sgt, priv->dir); dma_resv_unlock(dmabuf->resv); buffer->access->detach_dmabuf(buffer, priv->block); dma_buf_detach(attach->dmabuf, attach); dma_buf_put(dmabuf); kfree(priv); } static void iio_buffer_dmabuf_get(struct dma_buf_attachment *attach) { struct iio_dmabuf_priv *priv = attach->importer_priv; kref_get(&priv->ref); } static void iio_buffer_dmabuf_put(struct dma_buf_attachment *attach) { struct iio_dmabuf_priv *priv = attach->importer_priv; kref_put(&priv->ref, iio_buffer_dmabuf_release); } static int iio_buffer_chrdev_release(struct inode *inode, struct file *filep) { struct iio_dev_buffer_pair *ib = filep->private_data; struct iio_dev *indio_dev = ib->indio_dev; struct iio_buffer *buffer = ib->buffer; struct iio_dmabuf_priv *priv, *tmp; wake_up(&buffer->pollq); guard(mutex)(&buffer->dmabufs_mutex); /* Close all attached DMABUFs */ list_for_each_entry_safe(priv, tmp, &buffer->dmabufs, entry) { list_del_init(&priv->entry); iio_buffer_dmabuf_put(priv->attach); } kfree(ib); clear_bit(IIO_BUSY_BIT_POS, &buffer->flags); iio_device_put(indio_dev); return 0; } static int iio_dma_resv_lock(struct dma_buf *dmabuf, bool nonblock) { if (!nonblock) return dma_resv_lock_interruptible(dmabuf->resv, NULL); if (!dma_resv_trylock(dmabuf->resv)) return -EBUSY; return 0; } static struct dma_buf_attachment * iio_buffer_find_attachment(struct iio_dev_buffer_pair *ib, struct dma_buf *dmabuf, bool nonblock) { struct device *dev = ib->indio_dev->dev.parent; struct iio_buffer *buffer = ib->buffer; struct dma_buf_attachment *attach = NULL; struct iio_dmabuf_priv *priv; guard(mutex)(&buffer->dmabufs_mutex); list_for_each_entry(priv, &buffer->dmabufs, entry) { if (priv->attach->dev == dev && priv->attach->dmabuf == dmabuf) { attach = priv->attach; break; } } if (attach) iio_buffer_dmabuf_get(attach); return attach ?: ERR_PTR(-EPERM); } static int iio_buffer_attach_dmabuf(struct iio_dev_buffer_pair *ib, int __user *user_fd, bool nonblock) { struct iio_dev *indio_dev = ib->indio_dev; struct iio_buffer *buffer = ib->buffer; struct dma_buf_attachment *attach; struct iio_dmabuf_priv *priv, *each; struct dma_buf *dmabuf; int err, fd; if (!buffer->access->attach_dmabuf || !buffer->access->detach_dmabuf || !buffer->access->enqueue_dmabuf) return -EPERM; if (copy_from_user(&fd, user_fd, sizeof(fd))) return -EFAULT; priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; spin_lock_init(&priv->lock); priv->context = dma_fence_context_alloc(1); dmabuf = dma_buf_get(fd); if (IS_ERR(dmabuf)) { err = PTR_ERR(dmabuf); goto err_free_priv; } attach = dma_buf_attach(dmabuf, indio_dev->dev.parent); if (IS_ERR(attach)) { err = PTR_ERR(attach); goto err_dmabuf_put; } err = iio_dma_resv_lock(dmabuf, nonblock); if (err) goto err_dmabuf_detach; priv->dir = buffer->direction == IIO_BUFFER_DIRECTION_IN ? DMA_FROM_DEVICE : DMA_TO_DEVICE; priv->sgt = dma_buf_map_attachment(attach, priv->dir); if (IS_ERR(priv->sgt)) { err = PTR_ERR(priv->sgt); dev_err(&indio_dev->dev, "Unable to map attachment: %d\n", err); goto err_resv_unlock; } kref_init(&priv->ref); priv->buffer = buffer; priv->attach = attach; attach->importer_priv = priv; priv->block = buffer->access->attach_dmabuf(buffer, attach); if (IS_ERR(priv->block)) { err = PTR_ERR(priv->block); goto err_dmabuf_unmap_attachment; } dma_resv_unlock(dmabuf->resv); mutex_lock(&buffer->dmabufs_mutex); /* * Check whether we already have an attachment for this driver/DMABUF * combo. If we do, refuse to attach. */ list_for_each_entry(each, &buffer->dmabufs, entry) { if (each->attach->dev == indio_dev->dev.parent && each->attach->dmabuf == dmabuf) { /* * We unlocked the reservation object, so going through * the cleanup code would mean re-locking it first. * At this stage it is simpler to free the attachment * using iio_buffer_dma_put(). */ mutex_unlock(&buffer->dmabufs_mutex); iio_buffer_dmabuf_put(attach); return -EBUSY; } } /* Otherwise, add the new attachment to our dmabufs list. */ list_add(&priv->entry, &buffer->dmabufs); mutex_unlock(&buffer->dmabufs_mutex); return 0; err_dmabuf_unmap_attachment: dma_buf_unmap_attachment(attach, priv->sgt, priv->dir); err_resv_unlock: dma_resv_unlock(dmabuf->resv); err_dmabuf_detach: dma_buf_detach(dmabuf, attach); err_dmabuf_put: dma_buf_put(dmabuf); err_free_priv: kfree(priv); return err; } static int iio_buffer_detach_dmabuf(struct iio_dev_buffer_pair *ib, int __user *user_req, bool nonblock) { struct iio_buffer *buffer = ib->buffer; struct iio_dev *indio_dev = ib->indio_dev; struct iio_dmabuf_priv *priv; struct dma_buf *dmabuf; int dmabuf_fd, ret = -EPERM; if (copy_from_user(&dmabuf_fd, user_req, sizeof(dmabuf_fd))) return -EFAULT; dmabuf = dma_buf_get(dmabuf_fd); if (IS_ERR(dmabuf)) return PTR_ERR(dmabuf); guard(mutex)(&buffer->dmabufs_mutex); list_for_each_entry(priv, &buffer->dmabufs, entry) { if (priv->attach->dev == indio_dev->dev.parent && priv->attach->dmabuf == dmabuf) { list_del(&priv->entry); /* Unref the reference from iio_buffer_attach_dmabuf() */ iio_buffer_dmabuf_put(priv->attach); ret = 0; break; } } dma_buf_put(dmabuf); return ret; } static const char * iio_buffer_dma_fence_get_driver_name(struct dma_fence *fence) { return "iio"; } static void iio_buffer_dma_fence_release(struct dma_fence *fence) { struct iio_dma_fence *iio_fence = container_of(fence, struct iio_dma_fence, base); kfree(iio_fence); } static const struct dma_fence_ops iio_buffer_dma_fence_ops = { .get_driver_name = iio_buffer_dma_fence_get_driver_name, .get_timeline_name = iio_buffer_dma_fence_get_driver_name, .release = iio_buffer_dma_fence_release, }; static int iio_buffer_enqueue_dmabuf(struct iio_dev_buffer_pair *ib, struct iio_dmabuf __user *iio_dmabuf_req, bool nonblock) { struct iio_buffer *buffer = ib->buffer; struct iio_dmabuf iio_dmabuf; struct dma_buf_attachment *attach; struct iio_dmabuf_priv *priv; struct iio_dma_fence *fence; struct dma_buf *dmabuf; unsigned long timeout; bool cookie, cyclic, dma_to_ram; long retl; u32 seqno; int ret; if (copy_from_user(&iio_dmabuf, iio_dmabuf_req, sizeof(iio_dmabuf))) return -EFAULT; if (iio_dmabuf.flags & ~IIO_BUFFER_DMABUF_SUPPORTED_FLAGS) return -EINVAL; cyclic = iio_dmabuf.flags & IIO_BUFFER_DMABUF_CYCLIC; /* Cyclic flag is only supported on output buffers */ if (cyclic && buffer->direction != IIO_BUFFER_DIRECTION_OUT) return -EINVAL; dmabuf = dma_buf_get(iio_dmabuf.fd); if (IS_ERR(dmabuf)) return PTR_ERR(dmabuf); if (!iio_dmabuf.bytes_used || iio_dmabuf.bytes_used > dmabuf->size) { ret = -EINVAL; goto err_dmabuf_put; } attach = iio_buffer_find_attachment(ib, dmabuf, nonblock); if (IS_ERR(attach)) { ret = PTR_ERR(attach); goto err_dmabuf_put; } priv = attach->importer_priv; fence = kmalloc(sizeof(*fence), GFP_KERNEL); if (!fence) { ret = -ENOMEM; goto err_attachment_put; } fence->priv = priv; seqno = atomic_add_return(1, &priv->seqno); /* * The transfers are guaranteed to be processed in the order they are * enqueued, so we can use a simple incrementing sequence number for * the dma_fence. */ dma_fence_init(&fence->base, &iio_buffer_dma_fence_ops, &priv->lock, priv->context, seqno); ret = iio_dma_resv_lock(dmabuf, nonblock); if (ret) goto err_fence_put; timeout = nonblock ? 0 : msecs_to_jiffies(DMABUF_ENQUEUE_TIMEOUT_MS); dma_to_ram = buffer->direction == IIO_BUFFER_DIRECTION_IN; /* Make sure we don't have writers */ retl = dma_resv_wait_timeout(dmabuf->resv, dma_resv_usage_rw(dma_to_ram), true, timeout); if (retl == 0) retl = -EBUSY; if (retl < 0) { ret = (int)retl; goto err_resv_unlock; } if (buffer->access->lock_queue) buffer->access->lock_queue(buffer); ret = dma_resv_reserve_fences(dmabuf->resv, 1); if (ret) goto err_queue_unlock; dma_resv_add_fence(dmabuf->resv, &fence->base, dma_to_ram ? DMA_RESV_USAGE_WRITE : DMA_RESV_USAGE_READ); dma_resv_unlock(dmabuf->resv); cookie = dma_fence_begin_signalling(); ret = buffer->access->enqueue_dmabuf(buffer, priv->block, &fence->base, priv->sgt, iio_dmabuf.bytes_used, cyclic); if (ret) { /* * DMABUF enqueue failed, but we already added the fence. * Signal the error through the fence completion mechanism. */ iio_buffer_signal_dmabuf_done(&fence->base, ret); } if (buffer->access->unlock_queue) buffer->access->unlock_queue(buffer); dma_fence_end_signalling(cookie); dma_buf_put(dmabuf); return ret; err_queue_unlock: if (buffer->access->unlock_queue) buffer->access->unlock_queue(buffer); err_resv_unlock: dma_resv_unlock(dmabuf->resv); err_fence_put: dma_fence_put(&fence->base); err_attachment_put: iio_buffer_dmabuf_put(attach); err_dmabuf_put: dma_buf_put(dmabuf); return ret; } static void iio_buffer_cleanup(struct work_struct *work) { struct iio_dma_fence *fence = container_of(work, struct iio_dma_fence, work); struct iio_dmabuf_priv *priv = fence->priv; struct dma_buf_attachment *attach = priv->attach; dma_fence_put(&fence->base); iio_buffer_dmabuf_put(attach); } void iio_buffer_signal_dmabuf_done(struct dma_fence *fence, int ret) { struct iio_dma_fence *iio_fence = container_of(fence, struct iio_dma_fence, base); bool cookie = dma_fence_begin_signalling(); /* * Get a reference to the fence, so that it's not freed as soon as * it's signaled. */ dma_fence_get(fence); fence->error = ret; dma_fence_signal(fence); dma_fence_end_signalling(cookie); /* * The fence will be unref'd in iio_buffer_cleanup. * It can't be done here, as the unref functions might try to lock the * resv object, which can deadlock. */ INIT_WORK(&iio_fence->work, iio_buffer_cleanup); schedule_work(&iio_fence->work); } EXPORT_SYMBOL_GPL(iio_buffer_signal_dmabuf_done); static long iio_buffer_chrdev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct iio_dev_buffer_pair *ib = filp->private_data; void __user *_arg = (void __user *)arg; bool nonblock = filp->f_flags & O_NONBLOCK; switch (cmd) { case IIO_BUFFER_DMABUF_ATTACH_IOCTL: return iio_buffer_attach_dmabuf(ib, _arg, nonblock); case IIO_BUFFER_DMABUF_DETACH_IOCTL: return iio_buffer_detach_dmabuf(ib, _arg, nonblock); case IIO_BUFFER_DMABUF_ENQUEUE_IOCTL: return iio_buffer_enqueue_dmabuf(ib, _arg, nonblock); default: return -EINVAL; } } static const struct file_operations iio_buffer_chrdev_fileops = { .owner = THIS_MODULE, .llseek = noop_llseek, .read = iio_buffer_read, .write = iio_buffer_write, .unlocked_ioctl = iio_buffer_chrdev_ioctl, .compat_ioctl = compat_ptr_ioctl, .poll = iio_buffer_poll, .release = iio_buffer_chrdev_release, }; static long iio_device_buffer_getfd(struct iio_dev *indio_dev, unsigned long arg) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); int __user *ival = (int __user *)arg; struct iio_dev_buffer_pair *ib; struct iio_buffer *buffer; int fd, idx, ret; if (copy_from_user(&idx, ival, sizeof(idx))) return -EFAULT; if (idx >= iio_dev_opaque->attached_buffers_cnt) return -ENODEV; iio_device_get(indio_dev); buffer = iio_dev_opaque->attached_buffers[idx]; if (test_and_set_bit(IIO_BUSY_BIT_POS, &buffer->flags)) { ret = -EBUSY; goto error_iio_dev_put; } ib = kzalloc(sizeof(*ib), GFP_KERNEL); if (!ib) { ret = -ENOMEM; goto error_clear_busy_bit; } ib->indio_dev = indio_dev; ib->buffer = buffer; fd = anon_inode_getfd("iio:buffer", &iio_buffer_chrdev_fileops, ib, O_RDWR | O_CLOEXEC); if (fd < 0) { ret = fd; goto error_free_ib; } if (copy_to_user(ival, &fd, sizeof(fd))) { /* * "Leak" the fd, as there's not much we can do about this * anyway. 'fd' might have been closed already, as * anon_inode_getfd() called fd_install() on it, which made * it reachable by userland. * * Instead of allowing a malicious user to play tricks with * us, rely on the process exit path to do any necessary * cleanup, as in releasing the file, if still needed. */ return -EFAULT; } return 0; error_free_ib: kfree(ib); error_clear_busy_bit: clear_bit(IIO_BUSY_BIT_POS, &buffer->flags); error_iio_dev_put: iio_device_put(indio_dev); return ret; } static long iio_device_buffer_ioctl(struct iio_dev *indio_dev, struct file *filp, unsigned int cmd, unsigned long arg) { switch (cmd) { case IIO_BUFFER_GET_FD_IOCTL: return iio_device_buffer_getfd(indio_dev, arg); default: return IIO_IOCTL_UNHANDLED; } } static int iio_channel_validate_scan_type(struct device *dev, int ch, const struct iio_scan_type *scan_type) { /* Verify that sample bits fit into storage */ if (scan_type->storagebits < scan_type->realbits + scan_type->shift) { dev_err(dev, "Channel %d storagebits (%d) < shifted realbits (%d + %d)\n", ch, scan_type->storagebits, scan_type->realbits, scan_type->shift); return -EINVAL; } return 0; } static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, struct iio_dev *indio_dev, int index) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_dev_attr *p; const struct iio_dev_attr *id_attr; struct attribute **attr; int ret, i, attrn, scan_el_attrcount, buffer_attrcount; const struct iio_chan_spec *channels; buffer_attrcount = 0; if (buffer->attrs) { while (buffer->attrs[buffer_attrcount]) buffer_attrcount++; } buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs); scan_el_attrcount = 0; INIT_LIST_HEAD(&buffer->buffer_attr_list); channels = indio_dev->channels; if (channels) { /* new magic */ for (i = 0; i < indio_dev->num_channels; i++) { const struct iio_scan_type *scan_type; if (channels[i].scan_index < 0) continue; if (channels[i].has_ext_scan_type) { int j; /* * get_current_scan_type is required when using * extended scan types. */ if (!indio_dev->info->get_current_scan_type) { ret = -EINVAL; goto error_cleanup_dynamic; } for (j = 0; j < channels[i].num_ext_scan_type; j++) { scan_type = &channels[i].ext_scan_type[j]; ret = iio_channel_validate_scan_type( &indio_dev->dev, i, scan_type); if (ret) goto error_cleanup_dynamic; } } else { scan_type = &channels[i].scan_type; ret = iio_channel_validate_scan_type( &indio_dev->dev, i, scan_type); if (ret) goto error_cleanup_dynamic; } ret = iio_buffer_add_channel_sysfs(indio_dev, buffer, &channels[i]); if (ret < 0) goto error_cleanup_dynamic; scan_el_attrcount += ret; if (channels[i].type == IIO_TIMESTAMP) iio_dev_opaque->scan_index_timestamp = channels[i].scan_index; } if (indio_dev->masklength && !buffer->scan_mask) { buffer->scan_mask = bitmap_zalloc(indio_dev->masklength, GFP_KERNEL); if (!buffer->scan_mask) { ret = -ENOMEM; goto error_cleanup_dynamic; } } } attrn = buffer_attrcount + scan_el_attrcount; attr = kcalloc(attrn + 1, sizeof(*attr), GFP_KERNEL); if (!attr) { ret = -ENOMEM; goto error_free_scan_mask; } memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs)); if (!buffer->access->set_length) attr[0] = &dev_attr_length_ro.attr; if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK) attr[2] = &dev_attr_watermark_ro.attr; if (buffer->attrs) for (i = 0, id_attr = buffer->attrs[i]; (id_attr = buffer->attrs[i]); i++) attr[ARRAY_SIZE(iio_buffer_attrs) + i] = (struct attribute *)&id_attr->dev_attr.attr; buffer->buffer_group.attrs = attr; for (i = 0; i < buffer_attrcount; i++) { struct attribute *wrapped; wrapped = iio_buffer_wrap_attr(buffer, attr[i]); if (!wrapped) { ret = -ENOMEM; goto error_free_buffer_attrs; } attr[i] = wrapped; } attrn = 0; list_for_each_entry(p, &buffer->buffer_attr_list, l) attr[attrn++] = &p->dev_attr.attr; buffer->buffer_group.name = kasprintf(GFP_KERNEL, "buffer%d", index); if (!buffer->buffer_group.name) { ret = -ENOMEM; goto error_free_buffer_attrs; } ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group); if (ret) goto error_free_buffer_attr_group_name; /* we only need to register the legacy groups for the first buffer */ if (index > 0) return 0; ret = iio_buffer_register_legacy_sysfs_groups(indio_dev, attr, buffer_attrcount, scan_el_attrcount); if (ret) goto error_free_buffer_attr_group_name; return 0; error_free_buffer_attr_group_name: kfree(buffer->buffer_group.name); error_free_buffer_attrs: kfree(buffer->buffer_group.attrs); error_free_scan_mask: bitmap_free(buffer->scan_mask); error_cleanup_dynamic: iio_free_chan_devattr_list(&buffer->buffer_attr_list); return ret; } static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer, struct iio_dev *indio_dev, int index) { if (index == 0) iio_buffer_unregister_legacy_sysfs_groups(indio_dev); bitmap_free(buffer->scan_mask); kfree(buffer->buffer_group.name); kfree(buffer->buffer_group.attrs); iio_free_chan_devattr_list(&buffer->buffer_attr_list); } int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); const struct iio_chan_spec *channels; struct iio_buffer *buffer; int ret, i, idx; size_t sz; channels = indio_dev->channels; if (channels) { int ml = 0; for (i = 0; i < indio_dev->num_channels; i++) ml = max(ml, channels[i].scan_index + 1); indio_dev->masklength = ml; } if (!iio_dev_opaque->attached_buffers_cnt) return 0; for (idx = 0; idx < iio_dev_opaque->attached_buffers_cnt; idx++) { buffer = iio_dev_opaque->attached_buffers[idx]; ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, idx); if (ret) goto error_unwind_sysfs_and_mask; } sz = sizeof(*iio_dev_opaque->buffer_ioctl_handler); iio_dev_opaque->buffer_ioctl_handler = kzalloc(sz, GFP_KERNEL); if (!iio_dev_opaque->buffer_ioctl_handler) { ret = -ENOMEM; goto error_unwind_sysfs_and_mask; } iio_dev_opaque->buffer_ioctl_handler->ioctl = iio_device_buffer_ioctl; iio_device_ioctl_handler_register(indio_dev, iio_dev_opaque->buffer_ioctl_handler); return 0; error_unwind_sysfs_and_mask: while (idx--) { buffer = iio_dev_opaque->attached_buffers[idx]; __iio_buffer_free_sysfs_and_mask(buffer, indio_dev, idx); } return ret; } void iio_buffers_free_sysfs_and_mask(struct iio_dev *indio_dev) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer; int i; if (!iio_dev_opaque->attached_buffers_cnt) return; iio_device_ioctl_handler_unregister(iio_dev_opaque->buffer_ioctl_handler); kfree(iio_dev_opaque->buffer_ioctl_handler); for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) { buffer = iio_dev_opaque->attached_buffers[i]; __iio_buffer_free_sysfs_and_mask(buffer, indio_dev, i); } } /** * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected * @indio_dev: the iio device * @mask: scan mask to be checked * * Return true if exactly one bit is set in the scan mask, false otherwise. It * can be used for devices where only one channel can be active for sampling at * a time. */ bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, const unsigned long *mask) { return bitmap_weight(mask, indio_dev->masklength) == 1; } EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot); static const void *iio_demux(struct iio_buffer *buffer, const void *datain) { struct iio_demux_table *t; if (list_empty(&buffer->demux_list)) return datain; list_for_each_entry(t, &buffer->demux_list, l) memcpy(buffer->demux_bounce + t->to, datain + t->from, t->length); return buffer->demux_bounce; } static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data) { const void *dataout = iio_demux(buffer, data); int ret; ret = buffer->access->store_to(buffer, dataout); if (ret) return ret; /* * We can't just test for watermark to decide if we wake the poll queue * because read may request less samples than the watermark. */ wake_up_interruptible_poll(&buffer->pollq, EPOLLIN | EPOLLRDNORM); return 0; } /** * iio_push_to_buffers() - push to a registered buffer. * @indio_dev: iio_dev structure for device. * @data: Full scan. */ int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); int ret; struct iio_buffer *buf; list_for_each_entry(buf, &iio_dev_opaque->buffer_list, buffer_list) { ret = iio_push_to_buffer(buf, data); if (ret < 0) return ret; } return 0; } EXPORT_SYMBOL_GPL(iio_push_to_buffers); /** * iio_push_to_buffers_with_ts_unaligned() - push to registered buffer, * no alignment or space requirements. * @indio_dev: iio_dev structure for device. * @data: channel data excluding the timestamp. * @data_sz: size of data. * @timestamp: timestamp for the sample data. * * This special variant of iio_push_to_buffers_with_timestamp() does * not require space for the timestamp, or 8 byte alignment of data. * It does however require an allocation on first call and additional * copies on all calls, so should be avoided if possible. */ int iio_push_to_buffers_with_ts_unaligned(struct iio_dev *indio_dev, const void *data, size_t data_sz, int64_t timestamp) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); /* * Conservative estimate - we can always safely copy the minimum * of either the data provided or the length of the destination buffer. * This relaxed limit allows the calling drivers to be lax about * tracking the size of the data they are pushing, at the cost of * unnecessary copying of padding. */ data_sz = min_t(size_t, indio_dev->scan_bytes, data_sz); if (iio_dev_opaque->bounce_buffer_size != indio_dev->scan_bytes) { void *bb; bb = devm_krealloc(&indio_dev->dev, iio_dev_opaque->bounce_buffer, indio_dev->scan_bytes, GFP_KERNEL); if (!bb) return -ENOMEM; iio_dev_opaque->bounce_buffer = bb; iio_dev_opaque->bounce_buffer_size = indio_dev->scan_bytes; } memcpy(iio_dev_opaque->bounce_buffer, data, data_sz); return iio_push_to_buffers_with_timestamp(indio_dev, iio_dev_opaque->bounce_buffer, timestamp); } EXPORT_SYMBOL_GPL(iio_push_to_buffers_with_ts_unaligned); /** * iio_buffer_release() - Free a buffer's resources * @ref: Pointer to the kref embedded in the iio_buffer struct * * This function is called when the last reference to the buffer has been * dropped. It will typically free all resources allocated by the buffer. Do not * call this function manually, always use iio_buffer_put() when done using a * buffer. */ static void iio_buffer_release(struct kref *ref) { struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref); mutex_destroy(&buffer->dmabufs_mutex); buffer->access->release(buffer); } /** * iio_buffer_get() - Grab a reference to the buffer * @buffer: The buffer to grab a reference for, may be NULL * * Returns the pointer to the buffer that was passed into the function. */ struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer) { if (buffer) kref_get(&buffer->ref); return buffer; } EXPORT_SYMBOL_GPL(iio_buffer_get); /** * iio_buffer_put() - Release the reference to the buffer * @buffer: The buffer to release the reference for, may be NULL */ void iio_buffer_put(struct iio_buffer *buffer) { if (buffer) kref_put(&buffer->ref, iio_buffer_release); } EXPORT_SYMBOL_GPL(iio_buffer_put); /** * iio_device_attach_buffer - Attach a buffer to a IIO device * @indio_dev: The device the buffer should be attached to * @buffer: The buffer to attach to the device * * Return 0 if successful, negative if error. * * This function attaches a buffer to a IIO device. The buffer stays attached to * the device until the device is freed. For legacy reasons, the first attached * buffer will also be assigned to 'indio_dev->buffer'. * The array allocated here, will be free'd via the iio_device_detach_buffers() * call which is handled by the iio_device_free(). */ int iio_device_attach_buffer(struct iio_dev *indio_dev, struct iio_buffer *buffer) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer **new, **old = iio_dev_opaque->attached_buffers; unsigned int cnt = iio_dev_opaque->attached_buffers_cnt; cnt++; new = krealloc(old, sizeof(*new) * cnt, GFP_KERNEL); if (!new) return -ENOMEM; iio_dev_opaque->attached_buffers = new; buffer = iio_buffer_get(buffer); /* first buffer is legacy; attach it to the IIO device directly */ if (!indio_dev->buffer) indio_dev->buffer = buffer; iio_dev_opaque->attached_buffers[cnt - 1] = buffer; iio_dev_opaque->attached_buffers_cnt = cnt; return 0; } EXPORT_SYMBOL_GPL(iio_device_attach_buffer);
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