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path: root/drivers/iio/industrialio-buffer.c
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-rw-r--r--drivers/iio/industrialio-buffer.c755
1 files changed, 755 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
new file mode 100644
index 000000000000..ac185b8694bd
--- /dev/null
+++ b/drivers/iio/industrialio-buffer.c
@@ -0,0 +1,755 @@
+/* The industrial I/O core
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * 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.
+ *
+ * Handling of buffer allocation / resizing.
+ *
+ *
+ * Things to look at here.
+ * - Better memory allocation techniques?
+ * - Alternative access techniques?
+ */
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+
+#include <linux/iio/iio.h>
+#include "iio_core.h"
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+
+static const char * const iio_endian_prefix[] = {
+ [IIO_BE] = "be",
+ [IIO_LE] = "le",
+};
+
+/**
+ * iio_buffer_read_first_n_outer() - chrdev read for buffer access
+ *
+ * This function relies on all buffer implementations having an
+ * iio_buffer as their first element.
+ **/
+ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
+ size_t n, loff_t *f_ps)
+{
+ struct iio_dev *indio_dev = filp->private_data;
+ struct iio_buffer *rb = indio_dev->buffer;
+
+ if (!rb || !rb->access->read_first_n)
+ return -EINVAL;
+ return rb->access->read_first_n(rb, n, buf);
+}
+
+/**
+ * iio_buffer_poll() - poll the buffer to find out if it has data
+ */
+unsigned int iio_buffer_poll(struct file *filp,
+ struct poll_table_struct *wait)
+{
+ struct iio_dev *indio_dev = filp->private_data;
+ struct iio_buffer *rb = indio_dev->buffer;
+
+ poll_wait(filp, &rb->pollq, wait);
+ if (rb->stufftoread)
+ return POLLIN | POLLRDNORM;
+ /* need a way of knowing if there may be enough data... */
+ return 0;
+}
+
+void iio_buffer_init(struct iio_buffer *buffer)
+{
+ INIT_LIST_HEAD(&buffer->demux_list);
+ init_waitqueue_head(&buffer->pollq);
+}
+EXPORT_SYMBOL(iio_buffer_init);
+
+static ssize_t iio_show_scan_index(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(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_attr *this_attr = to_iio_dev_attr(attr);
+ u8 type = this_attr->c->scan_type.endianness;
+
+ if (type == IIO_CPU) {
+#ifdef __LITTLE_ENDIAN
+ type = IIO_LE;
+#else
+ type = IIO_BE;
+#endif
+ }
+ return sprintf(buf, "%s:%c%d/%d>>%u\n",
+ iio_endian_prefix[type],
+ this_attr->c->scan_type.sign,
+ this_attr->c->scan_type.realbits,
+ this_attr->c->scan_type.storagebits,
+ this_attr->c->scan_type.shift);
+}
+
+static ssize_t iio_scan_el_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int ret;
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+
+ ret = test_bit(to_iio_dev_attr(attr)->address,
+ indio_dev->buffer->scan_mask);
+
+ return sprintf(buf, "%d\n", ret);
+}
+
+static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
+{
+ clear_bit(bit, buffer->scan_mask);
+ return 0;
+}
+
+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_buffer *buffer = indio_dev->buffer;
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+ ret = strtobool(buf, &state);
+ if (ret < 0)
+ return ret;
+ mutex_lock(&indio_dev->mlock);
+ if (iio_buffer_enabled(indio_dev)) {
+ ret = -EBUSY;
+ goto error_ret;
+ }
+ ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
+ if (ret < 0)
+ goto error_ret;
+ if (!state && ret) {
+ ret = iio_scan_mask_clear(buffer, this_attr->address);
+ if (ret)
+ goto error_ret;
+ } else if (state && !ret) {
+ ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
+ if (ret)
+ goto error_ret;
+ }
+
+error_ret:
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret < 0 ? ret : len;
+
+}
+
+static ssize_t iio_scan_el_ts_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ return sprintf(buf, "%d\n", indio_dev->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);
+ bool state;
+
+ ret = strtobool(buf, &state);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&indio_dev->mlock);
+ if (iio_buffer_enabled(indio_dev)) {
+ ret = -EBUSY;
+ goto error_ret;
+ }
+ indio_dev->buffer->scan_timestamp = state;
+ indio_dev->scan_timestamp = state;
+error_ret:
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret ? ret : len;
+}
+
+static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ int ret, attrcount = 0;
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ ret = __iio_add_chan_devattr("index",
+ chan,
+ &iio_show_scan_index,
+ NULL,
+ 0,
+ 0,
+ &indio_dev->dev,
+ &buffer->scan_el_dev_attr_list);
+ if (ret)
+ goto error_ret;
+ attrcount++;
+ ret = __iio_add_chan_devattr("type",
+ chan,
+ &iio_show_fixed_type,
+ NULL,
+ 0,
+ 0,
+ &indio_dev->dev,
+ &buffer->scan_el_dev_attr_list);
+ if (ret)
+ goto error_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,
+ 0,
+ &indio_dev->dev,
+ &buffer->scan_el_dev_attr_list);
+ else
+ ret = __iio_add_chan_devattr("en",
+ chan,
+ &iio_scan_el_ts_show,
+ &iio_scan_el_ts_store,
+ chan->scan_index,
+ 0,
+ &indio_dev->dev,
+ &buffer->scan_el_dev_attr_list);
+ attrcount++;
+ ret = attrcount;
+error_ret:
+ return ret;
+}
+
+static void iio_buffer_remove_and_free_scan_dev_attr(struct iio_dev *indio_dev,
+ struct iio_dev_attr *p)
+{
+ kfree(p->dev_attr.attr.name);
+ kfree(p);
+}
+
+static void __iio_buffer_attr_cleanup(struct iio_dev *indio_dev)
+{
+ struct iio_dev_attr *p, *n;
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ list_for_each_entry_safe(p, n,
+ &buffer->scan_el_dev_attr_list, l)
+ iio_buffer_remove_and_free_scan_dev_attr(indio_dev, p);
+}
+
+static const char * const iio_scan_elements_group_name = "scan_elements";
+
+int iio_buffer_register(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *channels,
+ int num_channels)
+{
+ struct iio_dev_attr *p;
+ struct attribute **attr;
+ struct iio_buffer *buffer = indio_dev->buffer;
+ int ret, i, attrn, attrcount, attrcount_orig = 0;
+
+ if (buffer->attrs)
+ indio_dev->groups[indio_dev->groupcounter++] = buffer->attrs;
+
+ if (buffer->scan_el_attrs != NULL) {
+ attr = buffer->scan_el_attrs->attrs;
+ while (*attr++ != NULL)
+ attrcount_orig++;
+ }
+ attrcount = attrcount_orig;
+ INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
+ if (channels) {
+ /* new magic */
+ for (i = 0; i < num_channels; i++) {
+ /* Establish necessary mask length */
+ if (channels[i].scan_index >
+ (int)indio_dev->masklength - 1)
+ indio_dev->masklength
+ = indio_dev->channels[i].scan_index + 1;
+
+ ret = iio_buffer_add_channel_sysfs(indio_dev,
+ &channels[i]);
+ if (ret < 0)
+ goto error_cleanup_dynamic;
+ attrcount += ret;
+ if (channels[i].type == IIO_TIMESTAMP)
+ indio_dev->scan_index_timestamp =
+ channels[i].scan_index;
+ }
+ if (indio_dev->masklength && buffer->scan_mask == NULL) {
+ buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
+ sizeof(*buffer->scan_mask),
+ GFP_KERNEL);
+ if (buffer->scan_mask == NULL) {
+ ret = -ENOMEM;
+ goto error_cleanup_dynamic;
+ }
+ }
+ }
+
+ buffer->scan_el_group.name = iio_scan_elements_group_name;
+
+ buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
+ sizeof(buffer->scan_el_group.attrs[0]),
+ GFP_KERNEL);
+ if (buffer->scan_el_group.attrs == NULL) {
+ ret = -ENOMEM;
+ goto error_free_scan_mask;
+ }
+ if (buffer->scan_el_attrs)
+ memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
+ sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
+ attrn = attrcount_orig;
+
+ list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
+ buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
+ indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
+
+ return 0;
+
+error_free_scan_mask:
+ kfree(buffer->scan_mask);
+error_cleanup_dynamic:
+ __iio_buffer_attr_cleanup(indio_dev);
+
+ return ret;
+}
+EXPORT_SYMBOL(iio_buffer_register);
+
+void iio_buffer_unregister(struct iio_dev *indio_dev)
+{
+ kfree(indio_dev->buffer->scan_mask);
+ kfree(indio_dev->buffer->scan_el_group.attrs);
+ __iio_buffer_attr_cleanup(indio_dev);
+}
+EXPORT_SYMBOL(iio_buffer_unregister);
+
+ssize_t iio_buffer_read_length(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ if (buffer->access->get_length)
+ return sprintf(buf, "%d\n",
+ buffer->access->get_length(buffer));
+
+ return 0;
+}
+EXPORT_SYMBOL(iio_buffer_read_length);
+
+ssize_t iio_buffer_write_length(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ int ret;
+ ulong val;
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (buffer->access->get_length)
+ if (val == buffer->access->get_length(buffer))
+ return len;
+
+ mutex_lock(&indio_dev->mlock);
+ if (iio_buffer_enabled(indio_dev)) {
+ ret = -EBUSY;
+ } else {
+ if (buffer->access->set_length)
+ buffer->access->set_length(buffer, val);
+ ret = 0;
+ }
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret ? ret : len;
+}
+EXPORT_SYMBOL(iio_buffer_write_length);
+
+ssize_t iio_buffer_store_enable(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ int ret;
+ bool requested_state, current_state;
+ int previous_mode;
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct iio_buffer *buffer = indio_dev->buffer;
+
+ mutex_lock(&indio_dev->mlock);
+ previous_mode = indio_dev->currentmode;
+ requested_state = !(buf[0] == '0');
+ current_state = iio_buffer_enabled(indio_dev);
+ if (current_state == requested_state) {
+ printk(KERN_INFO "iio-buffer, current state requested again\n");
+ goto done;
+ }
+ if (requested_state) {
+ if (indio_dev->setup_ops->preenable) {
+ ret = indio_dev->setup_ops->preenable(indio_dev);
+ if (ret) {
+ printk(KERN_ERR
+ "Buffer not started:"
+ "buffer preenable failed\n");
+ goto error_ret;
+ }
+ }
+ if (buffer->access->request_update) {
+ ret = buffer->access->request_update(buffer);
+ if (ret) {
+ printk(KERN_INFO
+ "Buffer not started:"
+ "buffer parameter update failed\n");
+ goto error_ret;
+ }
+ }
+ /* Definitely possible for devices to support both of these.*/
+ if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) {
+ if (!indio_dev->trig) {
+ printk(KERN_INFO
+ "Buffer not started: no trigger\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
+ } else if (indio_dev->modes & INDIO_BUFFER_HARDWARE)
+ indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
+ else { /* should never be reached */
+ ret = -EINVAL;
+ goto error_ret;
+ }
+
+ if (indio_dev->setup_ops->postenable) {
+ ret = indio_dev->setup_ops->postenable(indio_dev);
+ if (ret) {
+ printk(KERN_INFO
+ "Buffer not started:"
+ "postenable failed\n");
+ indio_dev->currentmode = previous_mode;
+ if (indio_dev->setup_ops->postdisable)
+ indio_dev->setup_ops->
+ postdisable(indio_dev);
+ goto error_ret;
+ }
+ }
+ } else {
+ if (indio_dev->setup_ops->predisable) {
+ ret = indio_dev->setup_ops->predisable(indio_dev);
+ if (ret)
+ goto error_ret;
+ }
+ indio_dev->currentmode = INDIO_DIRECT_MODE;
+ if (indio_dev->setup_ops->postdisable) {
+ ret = indio_dev->setup_ops->postdisable(indio_dev);
+ if (ret)
+ goto error_ret;
+ }
+ }
+done:
+ mutex_unlock(&indio_dev->mlock);
+ return len;
+
+error_ret:
+ mutex_unlock(&indio_dev->mlock);
+ return ret;
+}
+EXPORT_SYMBOL(iio_buffer_store_enable);
+
+ssize_t iio_buffer_show_enable(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ return sprintf(buf, "%d\n", iio_buffer_enabled(indio_dev));
+}
+EXPORT_SYMBOL(iio_buffer_show_enable);
+
+/* 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)
+{
+ if (bitmap_empty(mask, masklength))
+ return NULL;
+ while (*av_masks) {
+ if (bitmap_subset(mask, av_masks, masklength))
+ return av_masks;
+ av_masks += BITS_TO_LONGS(masklength);
+ }
+ return NULL;
+}
+
+static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask,
+ bool timestamp)
+{
+ const struct iio_chan_spec *ch;
+ unsigned bytes = 0;
+ int length, i;
+
+ /* How much space will the demuxed element take? */
+ for_each_set_bit(i, mask,
+ indio_dev->masklength) {
+ ch = iio_find_channel_from_si(indio_dev, i);
+ length = ch->scan_type.storagebits / 8;
+ bytes = ALIGN(bytes, length);
+ bytes += length;
+ }
+ if (timestamp) {
+ ch = iio_find_channel_from_si(indio_dev,
+ indio_dev->scan_index_timestamp);
+ length = ch->scan_type.storagebits / 8;
+ bytes = ALIGN(bytes, length);
+ bytes += length;
+ }
+ return bytes;
+}
+
+int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
+{
+ struct iio_buffer *buffer = indio_dev->buffer;
+ dev_dbg(&indio_dev->dev, "%s\n", __func__);
+
+ /* How much space will the demuxed element take? */
+ indio_dev->scan_bytes =
+ iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
+ buffer->scan_timestamp);
+ buffer->access->set_bytes_per_datum(buffer, indio_dev->scan_bytes);
+
+ /* What scan mask do we actually have ?*/
+ if (indio_dev->available_scan_masks)
+ indio_dev->active_scan_mask =
+ iio_scan_mask_match(indio_dev->available_scan_masks,
+ indio_dev->masklength,
+ buffer->scan_mask);
+ else
+ indio_dev->active_scan_mask = buffer->scan_mask;
+ iio_update_demux(indio_dev);
+
+ if (indio_dev->info->update_scan_mode)
+ return indio_dev->info
+ ->update_scan_mode(indio_dev,
+ indio_dev->active_scan_mask);
+ return 0;
+}
+EXPORT_SYMBOL(iio_sw_buffer_preenable);
+
+/**
+ * iio_scan_mask_set() - set particular bit in the scan mask
+ * @buffer: the buffer whose scan mask we are interested in
+ * @bit: the bit to be set.
+ **/
+int iio_scan_mask_set(struct iio_dev *indio_dev,
+ struct iio_buffer *buffer, int bit)
+{
+ const unsigned long *mask;
+ unsigned long *trialmask;
+
+ trialmask = kmalloc(sizeof(*trialmask)*
+ BITS_TO_LONGS(indio_dev->masklength),
+ GFP_KERNEL);
+
+ if (trialmask == NULL)
+ return -ENOMEM;
+ if (!indio_dev->masklength) {
+ WARN_ON("trying to set scanmask prior to registering buffer\n");
+ kfree(trialmask);
+ return -EINVAL;
+ }
+ bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
+ set_bit(bit, trialmask);
+
+ if (indio_dev->available_scan_masks) {
+ mask = iio_scan_mask_match(indio_dev->available_scan_masks,
+ indio_dev->masklength,
+ trialmask);
+ if (!mask) {
+ kfree(trialmask);
+ return -EINVAL;
+ }
+ }
+ bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
+
+ kfree(trialmask);
+
+ return 0;
+};
+EXPORT_SYMBOL_GPL(iio_scan_mask_set);
+
+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;
+
+ return test_bit(bit, buffer->scan_mask);
+};
+EXPORT_SYMBOL_GPL(iio_scan_mask_query);
+
+/**
+ * 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 from;
+ unsigned to;
+ unsigned length;
+ struct list_head l;
+};
+
+static unsigned char *iio_demux(struct iio_buffer *buffer,
+ unsigned char *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;
+}
+
+int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data,
+ s64 timestamp)
+{
+ unsigned char *dataout = iio_demux(buffer, data);
+
+ return buffer->access->store_to(buffer, dataout, timestamp);
+}
+EXPORT_SYMBOL_GPL(iio_push_to_buffer);
+
+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);
+ }
+}
+
+int iio_update_demux(struct iio_dev *indio_dev)
+{
+ const struct iio_chan_spec *ch;
+ struct iio_buffer *buffer = indio_dev->buffer;
+ int ret, in_ind = -1, out_ind, length;
+ unsigned in_loc = 0, out_loc = 0;
+ struct iio_demux_table *p;
+
+ /* 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,
+ indio_dev->active_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) {
+ in_ind = find_next_bit(indio_dev->active_scan_mask,
+ indio_dev->masklength,
+ in_ind + 1);
+ ch = iio_find_channel_from_si(indio_dev, in_ind);
+ length = ch->scan_type.storagebits/8;
+ /* Make sure we are aligned */
+ in_loc += length;
+ if (in_loc % length)
+ in_loc += length - in_loc % length;
+ }
+ p = kmalloc(sizeof(*p), GFP_KERNEL);
+ if (p == NULL) {
+ ret = -ENOMEM;
+ goto error_clear_mux_table;
+ }
+ ch = iio_find_channel_from_si(indio_dev, in_ind);
+ length = ch->scan_type.storagebits/8;
+ if (out_loc % length)
+ out_loc += length - out_loc % length;
+ if (in_loc % length)
+ in_loc += length - in_loc % length;
+ p->from = in_loc;
+ p->to = out_loc;
+ p->length = length;
+ list_add_tail(&p->l, &buffer->demux_list);
+ out_loc += length;
+ in_loc += length;
+ }
+ /* Relies on scan_timestamp being last */
+ if (buffer->scan_timestamp) {
+ p = kmalloc(sizeof(*p), GFP_KERNEL);
+ if (p == NULL) {
+ ret = -ENOMEM;
+ goto error_clear_mux_table;
+ }
+ ch = iio_find_channel_from_si(indio_dev,
+ indio_dev->scan_index_timestamp);
+ length = ch->scan_type.storagebits/8;
+ if (out_loc % length)
+ out_loc += length - out_loc % length;
+ if (in_loc % length)
+ in_loc += length - in_loc % length;
+ p->from = in_loc;
+ p->to = out_loc;
+ p->length = length;
+ list_add_tail(&p->l, &buffer->demux_list);
+ out_loc += length;
+ in_loc += length;
+ }
+ buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
+ if (buffer->demux_bounce == NULL) {
+ ret = -ENOMEM;
+ goto error_clear_mux_table;
+ }
+ return 0;
+
+error_clear_mux_table:
+ iio_buffer_demux_free(buffer);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_update_demux);