linux/drivers/iio/industrialio-buffer.c
Linus Torvalds 53ee983378 Staging driver patches for 3.17-rc1
Here's the big pull request for the staging driver tree for 3.17-rc1.
 
 Lots of things in here, over 2000 patches, but the best part is this:
  1480 files changed, 39070 insertions(+), 254659 deletions(-)
 
 Thanks to the great work of Kristina Martšenko, 14 different staging
 drivers have been removed from the tree as they were obsolete and no one
 was willing to work on cleaning them up.  Other than the driver
 removals, loads of cleanups are in here (comedi, lustre, etc.) as well
 as the usual IIO driver updates and additions.
 
 All of this has been in the linux-next tree for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging driver updates from Greg KH:
 "Here's the big pull request for the staging driver tree for 3.17-rc1.

  Lots of things in here, over 2000 patches, but the best part is this:
   1480 files changed, 39070 insertions(+), 254659 deletions(-)

  Thanks to the great work of Kristina Martšenko, 14 different staging
  drivers have been removed from the tree as they were obsolete and no
  one was willing to work on cleaning them up.  Other than the driver
  removals, loads of cleanups are in here (comedi, lustre, etc.) as well
  as the usual IIO driver updates and additions.

  All of this has been in the linux-next tree for a while"

* tag 'staging-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (2199 commits)
  staging: comedi: addi_apci_1564: remove diagnostic interrupt support code
  staging: comedi: addi_apci_1564: add subdevice to check diagnostic status
  staging: wlan-ng: coding style problem fix
  staging: wlan-ng: fixing coding style problems
  staging: comedi: ii_pci20kc: request and ioremap memory
  staging: lustre: bitwise vs logical typo
  staging: dgnc: Remove unneeded dgnc_trace.c and dgnc_trace.h
  staging: dgnc: rephrase comment
  staging: comedi: ni_tio: remove some dead code
  staging: rtl8723au: Fix static symbol sparse warning
  staging: rtl8723au: usb_dvobj_init(): Remove unused variable 'pdev_desc'
  staging: rtl8723au: Do not duplicate kernel provided USB macros
  staging: rtl8723au: Remove never set struct pwrctrl_priv.bHWPowerdown
  staging: rtl8723au: Remove two never set variables
  staging: rtl8723au: RSSI_test is never set
  staging:r8190: coding style: Fixed checkpatch reported Error
  staging:r8180: coding style: Fixed too long lines
  staging:r8180: coding style: Fixed commenting style
  staging: lustre: ptlrpc: lproc_ptlrpc.c - fix dereferenceing user space buffer
  staging: lustre: ldlm: ldlm_resource.c - fix dereferenceing user space buffer
  ...
2014-08-04 18:36:12 -07:00

1107 lines
28 KiB
C

/* 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/sched.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",
};
static bool iio_buffer_is_active(struct iio_buffer *buf)
{
return !list_empty(&buf->buffer_list);
}
static bool iio_buffer_data_available(struct iio_buffer *buf)
{
return buf->access->data_available(buf);
}
/**
* 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;
int ret;
if (!indio_dev->info)
return -ENODEV;
if (!rb || !rb->access->read_first_n)
return -EINVAL;
do {
if (!iio_buffer_data_available(rb)) {
if (filp->f_flags & O_NONBLOCK)
return -EAGAIN;
ret = wait_event_interruptible(rb->pollq,
iio_buffer_data_available(rb) ||
indio_dev->info == NULL);
if (ret)
return ret;
if (indio_dev->info == NULL)
return -ENODEV;
}
ret = rb->access->read_first_n(rb, n, buf);
if (ret == 0 && (filp->f_flags & O_NONBLOCK))
ret = -EAGAIN;
} while (ret == 0);
return ret;
}
/**
* 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;
if (!indio_dev->info)
return -ENODEV;
poll_wait(filp, &rb->pollq, wait);
if (iio_buffer_data_available(rb))
return POLLIN | POLLRDNORM;
/* need a way of knowing if there may be enough data... */
return 0;
}
/**
* 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)
{
if (!indio_dev->buffer)
return;
wake_up(&indio_dev->buffer->pollq);
}
void iio_buffer_init(struct iio_buffer *buffer)
{
INIT_LIST_HEAD(&buffer->demux_list);
INIT_LIST_HEAD(&buffer->buffer_list);
init_waitqueue_head(&buffer->pollq);
kref_init(&buffer->ref);
}
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
}
if (this_attr->c->scan_type.repeat > 1)
return sprintf(buf, "%s:%c%d/%dX%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.repeat,
this_attr->c->scan_type.shift);
else
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);
/* Ensure ret is 0 or 1. */
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_is_active(indio_dev->buffer)) {
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_is_active(indio_dev->buffer)) {
ret = -EBUSY;
goto error_ret;
}
indio_dev->buffer->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,
IIO_SEPARATE,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
if (ret)
return 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)
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,
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);
if (ret)
return ret;
attrcount++;
ret = attrcount;
return ret;
}
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++) {
if (channels[i].scan_index < 0)
continue;
/* Establish necessary mask length */
if (channels[i].scan_index >
(int)indio_dev->masklength - 1)
indio_dev->masklength
= 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_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
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_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
}
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)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer;
unsigned int val;
int ret;
ret = kstrtouint(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_is_active(indio_dev->buffer)) {
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_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_is_active(indio_dev->buffer));
}
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 unsigned 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);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
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);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
length = ch->scan_type.storagebits / 8;
bytes = ALIGN(bytes, length);
bytes += length;
}
return bytes;
}
static void iio_buffer_activate(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
iio_buffer_get(buffer);
list_add(&buffer->buffer_list, &indio_dev->buffer_list);
}
static void iio_buffer_deactivate(struct iio_buffer *buffer)
{
list_del_init(&buffer->buffer_list);
iio_buffer_put(buffer);
}
void iio_disable_all_buffers(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer, *_buffer;
if (list_empty(&indio_dev->buffer_list))
return;
if (indio_dev->setup_ops->predisable)
indio_dev->setup_ops->predisable(indio_dev);
list_for_each_entry_safe(buffer, _buffer,
&indio_dev->buffer_list, buffer_list)
iio_buffer_deactivate(buffer);
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->postdisable(indio_dev);
if (indio_dev->available_scan_masks == NULL)
kfree(indio_dev->active_scan_mask);
}
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_update_buffers(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer,
struct iio_buffer *remove_buffer)
{
int ret;
int success = 0;
struct iio_buffer *buffer;
unsigned long *compound_mask;
const unsigned long *old_mask;
/* Wind down existing buffers - iff there are any */
if (!list_empty(&indio_dev->buffer_list)) {
if (indio_dev->setup_ops->predisable) {
ret = indio_dev->setup_ops->predisable(indio_dev);
if (ret)
return ret;
}
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable) {
ret = indio_dev->setup_ops->postdisable(indio_dev);
if (ret)
return ret;
}
}
/* Keep a copy of current setup to allow roll back */
old_mask = indio_dev->active_scan_mask;
if (!indio_dev->available_scan_masks)
indio_dev->active_scan_mask = NULL;
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(&indio_dev->buffer_list)) {
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->available_scan_masks == NULL)
kfree(old_mask);
return 0;
}
/* What scan mask do we actually have? */
compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
sizeof(long), GFP_KERNEL);
if (compound_mask == NULL) {
if (indio_dev->available_scan_masks == NULL)
kfree(old_mask);
return -ENOMEM;
}
indio_dev->scan_timestamp = 0;
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
indio_dev->masklength);
indio_dev->scan_timestamp |= buffer->scan_timestamp;
}
if (indio_dev->available_scan_masks) {
indio_dev->active_scan_mask =
iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
compound_mask);
if (indio_dev->active_scan_mask == NULL) {
/*
* Roll back.
* Note can only occur when adding a buffer.
*/
iio_buffer_deactivate(insert_buffer);
if (old_mask) {
indio_dev->active_scan_mask = old_mask;
success = -EINVAL;
}
else {
kfree(compound_mask);
ret = -EINVAL;
return ret;
}
}
} else {
indio_dev->active_scan_mask = compound_mask;
}
iio_update_demux(indio_dev);
/* Wind up again */
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 (%d)\n", ret);
goto error_remove_inserted;
}
}
indio_dev->scan_bytes =
iio_compute_scan_bytes(indio_dev,
indio_dev->active_scan_mask,
indio_dev->scan_timestamp);
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
iio_buffer_update_bytes_per_datum(indio_dev, buffer);
if (buffer->access->request_update) {
ret = buffer->access->request_update(buffer);
if (ret) {
printk(KERN_INFO
"Buffer not started: buffer parameter update failed (%d)\n", ret);
goto error_run_postdisable;
}
}
}
if (indio_dev->info->update_scan_mode) {
ret = indio_dev->info
->update_scan_mode(indio_dev,
indio_dev->active_scan_mask);
if (ret < 0) {
printk(KERN_INFO "Buffer not started: update scan mode failed (%d)\n", ret);
goto error_run_postdisable;
}
}
/* 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;
/* Can only occur on first buffer */
goto error_run_postdisable;
}
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_run_postdisable;
}
if (indio_dev->setup_ops->postenable) {
ret = indio_dev->setup_ops->postenable(indio_dev);
if (ret) {
printk(KERN_INFO
"Buffer not started: postenable failed (%d)\n", ret);
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->postdisable(indio_dev);
goto error_disable_all_buffers;
}
}
if (indio_dev->available_scan_masks)
kfree(compound_mask);
else
kfree(old_mask);
return success;
error_disable_all_buffers:
indio_dev->currentmode = INDIO_DIRECT_MODE;
error_run_postdisable:
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->postdisable(indio_dev);
error_remove_inserted:
if (insert_buffer)
iio_buffer_deactivate(insert_buffer);
indio_dev->active_scan_mask = old_mask;
kfree(compound_mask);
return ret;
}
int iio_update_buffers(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer,
struct iio_buffer *remove_buffer)
{
int ret;
if (insert_buffer == remove_buffer)
return 0;
mutex_lock(&indio_dev->info_exist_lock);
mutex_lock(&indio_dev->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) {
ret = 0;
goto out_unlock;
}
if (indio_dev->info == NULL) {
ret = -ENODEV;
goto out_unlock;
}
ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
out_unlock:
mutex_unlock(&indio_dev->mlock);
mutex_unlock(&indio_dev->info_exist_lock);
return ret;
}
EXPORT_SYMBOL_GPL(iio_update_buffers);
ssize_t iio_buffer_store_enable(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);
bool inlist;
ret = strtobool(buf, &requested_state);
if (ret < 0)
return ret;
mutex_lock(&indio_dev->mlock);
/* Find out if it is in the list */
inlist = iio_buffer_is_active(indio_dev->buffer);
/* Already in desired state */
if (inlist == requested_state)
goto done;
if (requested_state)
ret = __iio_update_buffers(indio_dev,
indio_dev->buffer, NULL);
else
ret = __iio_update_buffers(indio_dev,
NULL, indio_dev->buffer);
if (ret < 0)
goto done;
done:
mutex_unlock(&indio_dev->mlock);
return (ret < 0) ? ret : len;
}
EXPORT_SYMBOL(iio_buffer_store_enable);
/**
* 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 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.
*/
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");
goto err_invalid_mask;
}
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);
if (!mask)
goto err_invalid_mask;
}
bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
kfree(trialmask);
return 0;
err_invalid_mask:
kfree(trialmask);
return -EINVAL;
}
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;
/* Ensure return value is 0 or 1. */
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 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);
return buffer->access->store_to(buffer, dataout);
}
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_push_to_buffers(struct iio_dev *indio_dev, const void *data)
{
int ret;
struct iio_buffer *buf;
list_for_each_entry(buf, &indio_dev->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);
static int iio_buffer_update_demux(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
const struct iio_chan_spec *ch;
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,
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) {
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);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
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);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
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);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
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;
}
int iio_update_demux(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer;
int ret;
list_for_each_entry(buffer, &indio_dev->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, &indio_dev->buffer_list, buffer_list)
iio_buffer_demux_free(buffer);
return ret;
}
EXPORT_SYMBOL_GPL(iio_update_demux);
/**
* 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);
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);