linux/drivers/iio/industrialio-core.c

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/* 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.
*
* Based on elements of hwmon and input subsystems.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/cdev.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/anon_inodes.h>
#include <linux/debugfs.h>
#include <linux/iio/iio.h>
#include "iio_core.h"
#include "iio_core_trigger.h"
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
/* IDA to assign each registered device a unique id */
static DEFINE_IDA(iio_ida);
static dev_t iio_devt;
#define IIO_DEV_MAX 256
struct bus_type iio_bus_type = {
.name = "iio",
};
EXPORT_SYMBOL(iio_bus_type);
static struct dentry *iio_debugfs_dentry;
static const char * const iio_direction[] = {
[0] = "in",
[1] = "out",
};
static const char * const iio_chan_type_name_spec[] = {
[IIO_VOLTAGE] = "voltage",
[IIO_CURRENT] = "current",
[IIO_POWER] = "power",
[IIO_ACCEL] = "accel",
[IIO_ANGL_VEL] = "anglvel",
[IIO_MAGN] = "magn",
[IIO_LIGHT] = "illuminance",
[IIO_INTENSITY] = "intensity",
[IIO_PROXIMITY] = "proximity",
[IIO_TEMP] = "temp",
[IIO_INCLI] = "incli",
[IIO_ROT] = "rot",
[IIO_ANGL] = "angl",
[IIO_TIMESTAMP] = "timestamp",
[IIO_CAPACITANCE] = "capacitance",
[IIO_ALTVOLTAGE] = "altvoltage",
[IIO_CCT] = "cct",
};
static const char * const iio_modifier_names[] = {
[IIO_MOD_X] = "x",
[IIO_MOD_Y] = "y",
[IIO_MOD_Z] = "z",
[IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
[IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
[IIO_MOD_LIGHT_BOTH] = "both",
[IIO_MOD_LIGHT_IR] = "ir",
[IIO_MOD_LIGHT_CLEAR] = "clear",
[IIO_MOD_LIGHT_RED] = "red",
[IIO_MOD_LIGHT_GREEN] = "green",
[IIO_MOD_LIGHT_BLUE] = "blue",
};
/* relies on pairs of these shared then separate */
static const char * const iio_chan_info_postfix[] = {
[IIO_CHAN_INFO_RAW] = "raw",
[IIO_CHAN_INFO_PROCESSED] = "input",
[IIO_CHAN_INFO_SCALE] = "scale",
[IIO_CHAN_INFO_OFFSET] = "offset",
[IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
[IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
[IIO_CHAN_INFO_PEAK] = "peak_raw",
[IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
[IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
= "filter_low_pass_3db_frequency",
[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
[IIO_CHAN_INFO_FREQUENCY] = "frequency",
[IIO_CHAN_INFO_PHASE] = "phase",
[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
};
const struct iio_chan_spec
*iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
{
int i;
for (i = 0; i < indio_dev->num_channels; i++)
if (indio_dev->channels[i].scan_index == si)
return &indio_dev->channels[i];
return NULL;
}
/* This turns up an awful lot */
ssize_t iio_read_const_attr(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
}
EXPORT_SYMBOL(iio_read_const_attr);
static int __init iio_init(void)
{
int ret;
/* Register sysfs bus */
ret = bus_register(&iio_bus_type);
if (ret < 0) {
printk(KERN_ERR
"%s could not register bus type\n",
__FILE__);
goto error_nothing;
}
ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
if (ret < 0) {
printk(KERN_ERR "%s: failed to allocate char dev region\n",
__FILE__);
goto error_unregister_bus_type;
}
iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
return 0;
error_unregister_bus_type:
bus_unregister(&iio_bus_type);
error_nothing:
return ret;
}
static void __exit iio_exit(void)
{
if (iio_devt)
unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
bus_unregister(&iio_bus_type);
debugfs_remove(iio_debugfs_dentry);
}
#if defined(CONFIG_DEBUG_FS)
static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct iio_dev *indio_dev = file->private_data;
char buf[20];
unsigned val = 0;
ssize_t len;
int ret;
ret = indio_dev->info->debugfs_reg_access(indio_dev,
indio_dev->cached_reg_addr,
0, &val);
if (ret)
dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
len = snprintf(buf, sizeof(buf), "0x%X\n", val);
return simple_read_from_buffer(userbuf, count, ppos, buf, len);
}
static ssize_t iio_debugfs_write_reg(struct file *file,
const char __user *userbuf, size_t count, loff_t *ppos)
{
struct iio_dev *indio_dev = file->private_data;
unsigned reg, val;
char buf[80];
int ret;
count = min_t(size_t, count, (sizeof(buf)-1));
if (copy_from_user(buf, userbuf, count))
return -EFAULT;
buf[count] = 0;
ret = sscanf(buf, "%i %i", &reg, &val);
switch (ret) {
case 1:
indio_dev->cached_reg_addr = reg;
break;
case 2:
indio_dev->cached_reg_addr = reg;
ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
val, NULL);
if (ret) {
dev_err(indio_dev->dev.parent, "%s: write failed\n",
__func__);
return ret;
}
break;
default:
return -EINVAL;
}
return count;
}
static const struct file_operations iio_debugfs_reg_fops = {
.open = simple_open,
.read = iio_debugfs_read_reg,
.write = iio_debugfs_write_reg,
};
static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
{
debugfs_remove_recursive(indio_dev->debugfs_dentry);
}
static int iio_device_register_debugfs(struct iio_dev *indio_dev)
{
struct dentry *d;
if (indio_dev->info->debugfs_reg_access == NULL)
return 0;
if (!iio_debugfs_dentry)
return 0;
indio_dev->debugfs_dentry =
debugfs_create_dir(dev_name(&indio_dev->dev),
iio_debugfs_dentry);
if (indio_dev->debugfs_dentry == NULL) {
dev_warn(indio_dev->dev.parent,
"Failed to create debugfs directory\n");
return -EFAULT;
}
d = debugfs_create_file("direct_reg_access", 0644,
indio_dev->debugfs_dentry,
indio_dev, &iio_debugfs_reg_fops);
if (!d) {
iio_device_unregister_debugfs(indio_dev);
return -ENOMEM;
}
return 0;
}
#else
static int iio_device_register_debugfs(struct iio_dev *indio_dev)
{
return 0;
}
static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
{
}
#endif /* CONFIG_DEBUG_FS */
static ssize_t iio_read_channel_ext_info(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_chan_spec_ext_info *ext_info;
ext_info = &this_attr->c->ext_info[this_attr->address];
return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
}
static ssize_t iio_write_channel_ext_info(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_attr *this_attr = to_iio_dev_attr(attr);
const struct iio_chan_spec_ext_info *ext_info;
ext_info = &this_attr->c->ext_info[this_attr->address];
return ext_info->write(indio_dev, ext_info->private,
this_attr->c, buf, len);
}
ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
{
const struct iio_enum *e = (const struct iio_enum *)priv;
unsigned int i;
size_t len = 0;
if (!e->num_items)
return 0;
for (i = 0; i < e->num_items; ++i)
len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
/* replace last space with a newline */
buf[len - 1] = '\n';
return len;
}
EXPORT_SYMBOL_GPL(iio_enum_available_read);
ssize_t iio_enum_read(struct iio_dev *indio_dev,
uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
{
const struct iio_enum *e = (const struct iio_enum *)priv;
int i;
if (!e->get)
return -EINVAL;
i = e->get(indio_dev, chan);
if (i < 0)
return i;
else if (i >= e->num_items)
return -EINVAL;
return sprintf(buf, "%s\n", e->items[i]);
}
EXPORT_SYMBOL_GPL(iio_enum_read);
ssize_t iio_enum_write(struct iio_dev *indio_dev,
uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
size_t len)
{
const struct iio_enum *e = (const struct iio_enum *)priv;
unsigned int i;
int ret;
if (!e->set)
return -EINVAL;
for (i = 0; i < e->num_items; i++) {
if (sysfs_streq(buf, e->items[i]))
break;
}
if (i == e->num_items)
return -EINVAL;
ret = e->set(indio_dev, chan, i);
return ret ? ret : len;
}
EXPORT_SYMBOL_GPL(iio_enum_write);
static ssize_t iio_read_channel_info(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);
unsigned long long tmp;
int val, val2;
bool scale_db = false;
int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
&val, &val2, this_attr->address);
if (ret < 0)
return ret;
switch (ret) {
case IIO_VAL_INT:
return sprintf(buf, "%d\n", val);
case IIO_VAL_INT_PLUS_MICRO_DB:
scale_db = true;
case IIO_VAL_INT_PLUS_MICRO:
if (val2 < 0)
return sprintf(buf, "-%d.%06u%s\n", val, -val2,
scale_db ? " dB" : "");
else
return sprintf(buf, "%d.%06u%s\n", val, val2,
scale_db ? " dB" : "");
case IIO_VAL_INT_PLUS_NANO:
if (val2 < 0)
return sprintf(buf, "-%d.%09u\n", val, -val2);
else
return sprintf(buf, "%d.%09u\n", val, val2);
case IIO_VAL_FRACTIONAL:
tmp = div_s64((s64)val * 1000000000LL, val2);
val2 = do_div(tmp, 1000000000LL);
val = tmp;
return sprintf(buf, "%d.%09u\n", val, val2);
default:
return 0;
}
}
static ssize_t iio_write_channel_info(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_attr *this_attr = to_iio_dev_attr(attr);
int ret, integer = 0, fract = 0, fract_mult = 100000;
bool integer_part = true, negative = false;
/* Assumes decimal - precision based on number of digits */
if (!indio_dev->info->write_raw)
return -EINVAL;
if (indio_dev->info->write_raw_get_fmt)
switch (indio_dev->info->write_raw_get_fmt(indio_dev,
this_attr->c, this_attr->address)) {
case IIO_VAL_INT_PLUS_MICRO:
fract_mult = 100000;
break;
case IIO_VAL_INT_PLUS_NANO:
fract_mult = 100000000;
break;
default:
return -EINVAL;
}
if (buf[0] == '-') {
negative = true;
buf++;
}
while (*buf) {
if ('0' <= *buf && *buf <= '9') {
if (integer_part)
integer = integer*10 + *buf - '0';
else {
fract += fract_mult*(*buf - '0');
if (fract_mult == 1)
break;
fract_mult /= 10;
}
} else if (*buf == '\n') {
if (*(buf + 1) == '\0')
break;
else
return -EINVAL;
} else if (*buf == '.') {
integer_part = false;
} else {
return -EINVAL;
}
buf++;
}
if (negative) {
if (integer)
integer = -integer;
else
fract = -fract;
}
ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
integer, fract, this_attr->address);
if (ret)
return ret;
return len;
}
static
int __iio_device_attr_init(struct device_attribute *dev_attr,
const char *postfix,
struct iio_chan_spec const *chan,
ssize_t (*readfunc)(struct device *dev,
struct device_attribute *attr,
char *buf),
ssize_t (*writefunc)(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len),
bool generic)
{
int ret;
char *name_format, *full_postfix;
sysfs_attr_init(&dev_attr->attr);
/* Build up postfix of <extend_name>_<modifier>_postfix */
if (chan->modified && !generic) {
if (chan->extend_name)
full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
iio_modifier_names[chan
->channel2],
chan->extend_name,
postfix);
else
full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
iio_modifier_names[chan
->channel2],
postfix);
} else {
if (chan->extend_name == NULL)
full_postfix = kstrdup(postfix, GFP_KERNEL);
else
full_postfix = kasprintf(GFP_KERNEL,
"%s_%s",
chan->extend_name,
postfix);
}
if (full_postfix == NULL) {
ret = -ENOMEM;
goto error_ret;
}
if (chan->differential) { /* Differential can not have modifier */
if (generic)
name_format
= kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
iio_direction[chan->output],
iio_chan_type_name_spec[chan->type],
iio_chan_type_name_spec[chan->type],
full_postfix);
else if (chan->indexed)
name_format
= kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
iio_direction[chan->output],
iio_chan_type_name_spec[chan->type],
chan->channel,
iio_chan_type_name_spec[chan->type],
chan->channel2,
full_postfix);
else {
WARN_ON("Differential channels must be indexed\n");
ret = -EINVAL;
goto error_free_full_postfix;
}
} else { /* Single ended */
if (generic)
name_format
= kasprintf(GFP_KERNEL, "%s_%s_%s",
iio_direction[chan->output],
iio_chan_type_name_spec[chan->type],
full_postfix);
else if (chan->indexed)
name_format
= kasprintf(GFP_KERNEL, "%s_%s%d_%s",
iio_direction[chan->output],
iio_chan_type_name_spec[chan->type],
chan->channel,
full_postfix);
else
name_format
= kasprintf(GFP_KERNEL, "%s_%s_%s",
iio_direction[chan->output],
iio_chan_type_name_spec[chan->type],
full_postfix);
}
if (name_format == NULL) {
ret = -ENOMEM;
goto error_free_full_postfix;
}
dev_attr->attr.name = kasprintf(GFP_KERNEL,
name_format,
chan->channel,
chan->channel2);
if (dev_attr->attr.name == NULL) {
ret = -ENOMEM;
goto error_free_name_format;
}
if (readfunc) {
dev_attr->attr.mode |= S_IRUGO;
dev_attr->show = readfunc;
}
if (writefunc) {
dev_attr->attr.mode |= S_IWUSR;
dev_attr->store = writefunc;
}
kfree(name_format);
kfree(full_postfix);
return 0;
error_free_name_format:
kfree(name_format);
error_free_full_postfix:
kfree(full_postfix);
error_ret:
return ret;
}
static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
{
kfree(dev_attr->attr.name);
}
int __iio_add_chan_devattr(const char *postfix,
struct iio_chan_spec const *chan,
ssize_t (*readfunc)(struct device *dev,
struct device_attribute *attr,
char *buf),
ssize_t (*writefunc)(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len),
u64 mask,
bool generic,
struct device *dev,
struct list_head *attr_list)
{
int ret;
struct iio_dev_attr *iio_attr, *t;
iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
if (iio_attr == NULL) {
ret = -ENOMEM;
goto error_ret;
}
ret = __iio_device_attr_init(&iio_attr->dev_attr,
postfix, chan,
readfunc, writefunc, generic);
if (ret)
goto error_iio_dev_attr_free;
iio_attr->c = chan;
iio_attr->address = mask;
list_for_each_entry(t, attr_list, l)
if (strcmp(t->dev_attr.attr.name,
iio_attr->dev_attr.attr.name) == 0) {
if (!generic)
dev_err(dev, "tried to double register : %s\n",
t->dev_attr.attr.name);
ret = -EBUSY;
goto error_device_attr_deinit;
}
list_add(&iio_attr->l, attr_list);
return 0;
error_device_attr_deinit:
__iio_device_attr_deinit(&iio_attr->dev_attr);
error_iio_dev_attr_free:
kfree(iio_attr);
error_ret:
return ret;
}
static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan)
{
int ret, attrcount = 0;
int i;
staging:iio: Add extended IIO channel info Sometimes devices have per channel properties which either do not map nicely to the current channel info scheme (e.g. string properties) or are very device specific, so it does not make sense to add generic support for them. Currently drivers define these attributes by hand for each channel. Depending on the number of channels this can amount to quite a few lines of boilerplate code. Especially if a driver supports multiple variations of a chip with different numbers of channels. In this case it becomes necessary to have a individual attribute list per chip variation and also a individual iio_info struct. This patch introduces a new scheme for handling such per channel attributes called extended channel info attributes. A extended channel info attribute consist of a name, a flag whether it is shared and read and write callbacks. The read and write callbacks are similar to the {read,write}_raw callbacks and take a IIO device and a channel as their first parameters, but instead of pre-parsed integer values they directly get passed the raw string value, which has been written to the sysfs file. It is possible to assign a list of extended channel info attributes to a channel. For each extended channel info attribute the IIO core will create a new sysfs attribute conforming to the IIO channel naming spec for the channels type, similar as for normal info attributes. Read and write access to this sysfs attribute will be redirected to the extended channel info attributes read and write callbacks. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-21 17:38:12 +00:00
const struct iio_chan_spec_ext_info *ext_info;
if (chan->channel < 0)
return 0;
for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
chan,
&iio_read_channel_info,
&iio_write_channel_info,
i/2,
!(i%2),
&indio_dev->dev,
&indio_dev->channel_attr_list);
if (ret == -EBUSY && (i%2 == 0)) {
ret = 0;
continue;
}
if (ret < 0)
goto error_ret;
attrcount++;
}
staging:iio: Add extended IIO channel info Sometimes devices have per channel properties which either do not map nicely to the current channel info scheme (e.g. string properties) or are very device specific, so it does not make sense to add generic support for them. Currently drivers define these attributes by hand for each channel. Depending on the number of channels this can amount to quite a few lines of boilerplate code. Especially if a driver supports multiple variations of a chip with different numbers of channels. In this case it becomes necessary to have a individual attribute list per chip variation and also a individual iio_info struct. This patch introduces a new scheme for handling such per channel attributes called extended channel info attributes. A extended channel info attribute consist of a name, a flag whether it is shared and read and write callbacks. The read and write callbacks are similar to the {read,write}_raw callbacks and take a IIO device and a channel as their first parameters, but instead of pre-parsed integer values they directly get passed the raw string value, which has been written to the sysfs file. It is possible to assign a list of extended channel info attributes to a channel. For each extended channel info attribute the IIO core will create a new sysfs attribute conforming to the IIO channel naming spec for the channels type, similar as for normal info attributes. Read and write access to this sysfs attribute will be redirected to the extended channel info attributes read and write callbacks. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-21 17:38:12 +00:00
if (chan->ext_info) {
unsigned int i = 0;
for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
ret = __iio_add_chan_devattr(ext_info->name,
chan,
ext_info->read ?
&iio_read_channel_ext_info : NULL,
ext_info->write ?
&iio_write_channel_ext_info : NULL,
i,
ext_info->shared,
&indio_dev->dev,
&indio_dev->channel_attr_list);
i++;
if (ret == -EBUSY && ext_info->shared)
continue;
if (ret)
goto error_ret;
attrcount++;
}
}
ret = attrcount;
error_ret:
return ret;
}
static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
struct iio_dev_attr *p)
{
kfree(p->dev_attr.attr.name);
kfree(p);
}
static ssize_t iio_show_dev_name(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
return sprintf(buf, "%s\n", indio_dev->name);
}
static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
static int iio_device_register_sysfs(struct iio_dev *indio_dev)
{
int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
struct iio_dev_attr *p, *n;
struct attribute **attr;
/* First count elements in any existing group */
if (indio_dev->info->attrs) {
attr = indio_dev->info->attrs->attrs;
while (*attr++ != NULL)
attrcount_orig++;
}
attrcount = attrcount_orig;
/*
* New channel registration method - relies on the fact a group does
* not need to be initialized if its name is NULL.
*/
if (indio_dev->channels)
for (i = 0; i < indio_dev->num_channels; i++) {
ret = iio_device_add_channel_sysfs(indio_dev,
&indio_dev
->channels[i]);
if (ret < 0)
goto error_clear_attrs;
attrcount += ret;
}
if (indio_dev->name)
attrcount++;
indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
sizeof(indio_dev->chan_attr_group.attrs[0]),
GFP_KERNEL);
if (indio_dev->chan_attr_group.attrs == NULL) {
ret = -ENOMEM;
goto error_clear_attrs;
}
/* Copy across original attributes */
if (indio_dev->info->attrs)
memcpy(indio_dev->chan_attr_group.attrs,
indio_dev->info->attrs->attrs,
sizeof(indio_dev->chan_attr_group.attrs[0])
*attrcount_orig);
attrn = attrcount_orig;
/* Add all elements from the list. */
list_for_each_entry(p, &indio_dev->channel_attr_list, l)
indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
if (indio_dev->name)
indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
indio_dev->groups[indio_dev->groupcounter++] =
&indio_dev->chan_attr_group;
return 0;
error_clear_attrs:
list_for_each_entry_safe(p, n,
&indio_dev->channel_attr_list, l) {
list_del(&p->l);
iio_device_remove_and_free_read_attr(indio_dev, p);
}
return ret;
}
static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
{
struct iio_dev_attr *p, *n;
list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
list_del(&p->l);
iio_device_remove_and_free_read_attr(indio_dev, p);
}
kfree(indio_dev->chan_attr_group.attrs);
}
static void iio_dev_release(struct device *device)
{
struct iio_dev *indio_dev = dev_to_iio_dev(device);
iio: Fix potential use after free There is no guarantee that the last reference to the iio device has already been dropped when iio_device_free is called. This means that we can up calling iio_dev_release after iio_device_free which will lead to a use after free. As the general rule the struct containing the device should always be freed in the release callback. This is what this patch does, it moves freeing the iio device struct as well as releasing the idr reference to the release callback. To ensure that the device is not freed before calling iio_device_free the device_unregister call in iio_device_unregister is broken apart. iio_device_unregister will now only call device_del to remove the device from the system and iio_device_free will call put_device to drop the reference we obtained in iio_devce_alloc. We also have to take care that calling iio_device_free without having called iio_device_register still works (i.e. this can happen if something failed during device initialization). For this to work properly two minor changes were necessary: channel_attr_list needs to be initialized in iio_device_alloc and we have to check whether the chrdev has been registered before releasing it in iio_device_release. This change also brings iio_device_unregister and iio_device_free more in sync with iio_device_register and iio_device_alloc which call device_add and device_initialize respectively. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-04 08:41:42 +00:00
if (indio_dev->chrdev.dev)
cdev_del(&indio_dev->chrdev);
if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
iio_device_unregister_trigger_consumer(indio_dev);
iio_device_unregister_eventset(indio_dev);
iio_device_unregister_sysfs(indio_dev);
iio_device_unregister_debugfs(indio_dev);
iio: Fix potential use after free There is no guarantee that the last reference to the iio device has already been dropped when iio_device_free is called. This means that we can up calling iio_dev_release after iio_device_free which will lead to a use after free. As the general rule the struct containing the device should always be freed in the release callback. This is what this patch does, it moves freeing the iio device struct as well as releasing the idr reference to the release callback. To ensure that the device is not freed before calling iio_device_free the device_unregister call in iio_device_unregister is broken apart. iio_device_unregister will now only call device_del to remove the device from the system and iio_device_free will call put_device to drop the reference we obtained in iio_devce_alloc. We also have to take care that calling iio_device_free without having called iio_device_register still works (i.e. this can happen if something failed during device initialization). For this to work properly two minor changes were necessary: channel_attr_list needs to be initialized in iio_device_alloc and we have to check whether the chrdev has been registered before releasing it in iio_device_release. This change also brings iio_device_unregister and iio_device_free more in sync with iio_device_register and iio_device_alloc which call device_add and device_initialize respectively. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-04 08:41:42 +00:00
ida_simple_remove(&iio_ida, indio_dev->id);
kfree(indio_dev);
}
static struct device_type iio_dev_type = {
.name = "iio_device",
.release = iio_dev_release,
};
struct iio_dev *iio_device_alloc(int sizeof_priv)
{
struct iio_dev *dev;
size_t alloc_size;
alloc_size = sizeof(struct iio_dev);
if (sizeof_priv) {
alloc_size = ALIGN(alloc_size, IIO_ALIGN);
alloc_size += sizeof_priv;
}
/* ensure 32-byte alignment of whole construct ? */
alloc_size += IIO_ALIGN - 1;
dev = kzalloc(alloc_size, GFP_KERNEL);
if (dev) {
dev->dev.groups = dev->groups;
dev->dev.type = &iio_dev_type;
dev->dev.bus = &iio_bus_type;
device_initialize(&dev->dev);
dev_set_drvdata(&dev->dev, (void *)dev);
mutex_init(&dev->mlock);
mutex_init(&dev->info_exist_lock);
iio: Fix potential use after free There is no guarantee that the last reference to the iio device has already been dropped when iio_device_free is called. This means that we can up calling iio_dev_release after iio_device_free which will lead to a use after free. As the general rule the struct containing the device should always be freed in the release callback. This is what this patch does, it moves freeing the iio device struct as well as releasing the idr reference to the release callback. To ensure that the device is not freed before calling iio_device_free the device_unregister call in iio_device_unregister is broken apart. iio_device_unregister will now only call device_del to remove the device from the system and iio_device_free will call put_device to drop the reference we obtained in iio_devce_alloc. We also have to take care that calling iio_device_free without having called iio_device_register still works (i.e. this can happen if something failed during device initialization). For this to work properly two minor changes were necessary: channel_attr_list needs to be initialized in iio_device_alloc and we have to check whether the chrdev has been registered before releasing it in iio_device_release. This change also brings iio_device_unregister and iio_device_free more in sync with iio_device_register and iio_device_alloc which call device_add and device_initialize respectively. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-04 08:41:42 +00:00
INIT_LIST_HEAD(&dev->channel_attr_list);
dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
if (dev->id < 0) {
/* cannot use a dev_err as the name isn't available */
printk(KERN_ERR "Failed to get id\n");
kfree(dev);
return NULL;
}
dev_set_name(&dev->dev, "iio:device%d", dev->id);
}
return dev;
}
EXPORT_SYMBOL(iio_device_alloc);
void iio_device_free(struct iio_dev *dev)
{
iio: Fix potential use after free There is no guarantee that the last reference to the iio device has already been dropped when iio_device_free is called. This means that we can up calling iio_dev_release after iio_device_free which will lead to a use after free. As the general rule the struct containing the device should always be freed in the release callback. This is what this patch does, it moves freeing the iio device struct as well as releasing the idr reference to the release callback. To ensure that the device is not freed before calling iio_device_free the device_unregister call in iio_device_unregister is broken apart. iio_device_unregister will now only call device_del to remove the device from the system and iio_device_free will call put_device to drop the reference we obtained in iio_devce_alloc. We also have to take care that calling iio_device_free without having called iio_device_register still works (i.e. this can happen if something failed during device initialization). For this to work properly two minor changes were necessary: channel_attr_list needs to be initialized in iio_device_alloc and we have to check whether the chrdev has been registered before releasing it in iio_device_release. This change also brings iio_device_unregister and iio_device_free more in sync with iio_device_register and iio_device_alloc which call device_add and device_initialize respectively. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-04 08:41:42 +00:00
if (dev)
put_device(&dev->dev);
}
EXPORT_SYMBOL(iio_device_free);
/**
* iio_chrdev_open() - chrdev file open for buffer access and ioctls
**/
static int iio_chrdev_open(struct inode *inode, struct file *filp)
{
struct iio_dev *indio_dev = container_of(inode->i_cdev,
struct iio_dev, chrdev);
if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
return -EBUSY;
filp->private_data = indio_dev;
return 0;
}
/**
* iio_chrdev_release() - chrdev file close buffer access and ioctls
**/
static int iio_chrdev_release(struct inode *inode, struct file *filp)
{
struct iio_dev *indio_dev = container_of(inode->i_cdev,
struct iio_dev, chrdev);
clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
return 0;
}
/* Somewhat of a cross file organization violation - ioctls here are actually
* event related */
static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct iio_dev *indio_dev = filp->private_data;
int __user *ip = (int __user *)arg;
int fd;
if (cmd == IIO_GET_EVENT_FD_IOCTL) {
fd = iio_event_getfd(indio_dev);
if (copy_to_user(ip, &fd, sizeof(fd)))
return -EFAULT;
return 0;
}
return -EINVAL;
}
static const struct file_operations iio_buffer_fileops = {
.read = iio_buffer_read_first_n_outer_addr,
.release = iio_chrdev_release,
.open = iio_chrdev_open,
.poll = iio_buffer_poll_addr,
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = iio_ioctl,
.compat_ioctl = iio_ioctl,
};
static const struct iio_buffer_setup_ops noop_ring_setup_ops;
int iio_device_register(struct iio_dev *indio_dev)
{
int ret;
/* configure elements for the chrdev */
indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
ret = iio_device_register_debugfs(indio_dev);
if (ret) {
dev_err(indio_dev->dev.parent,
"Failed to register debugfs interfaces\n");
goto error_ret;
}
ret = iio_device_register_sysfs(indio_dev);
if (ret) {
dev_err(indio_dev->dev.parent,
"Failed to register sysfs interfaces\n");
goto error_unreg_debugfs;
}
ret = iio_device_register_eventset(indio_dev);
if (ret) {
dev_err(indio_dev->dev.parent,
"Failed to register event set\n");
goto error_free_sysfs;
}
if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
iio_device_register_trigger_consumer(indio_dev);
if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
indio_dev->setup_ops == NULL)
indio_dev->setup_ops = &noop_ring_setup_ops;
ret = device_add(&indio_dev->dev);
if (ret < 0)
goto error_unreg_eventset;
cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
indio_dev->chrdev.owner = indio_dev->info->driver_module;
ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
if (ret < 0)
goto error_del_device;
return 0;
error_del_device:
device_del(&indio_dev->dev);
error_unreg_eventset:
iio_device_unregister_eventset(indio_dev);
error_free_sysfs:
iio_device_unregister_sysfs(indio_dev);
error_unreg_debugfs:
iio_device_unregister_debugfs(indio_dev);
error_ret:
return ret;
}
EXPORT_SYMBOL(iio_device_register);
void iio_device_unregister(struct iio_dev *indio_dev)
{
mutex_lock(&indio_dev->info_exist_lock);
indio_dev->info = NULL;
mutex_unlock(&indio_dev->info_exist_lock);
iio: Fix potential use after free There is no guarantee that the last reference to the iio device has already been dropped when iio_device_free is called. This means that we can up calling iio_dev_release after iio_device_free which will lead to a use after free. As the general rule the struct containing the device should always be freed in the release callback. This is what this patch does, it moves freeing the iio device struct as well as releasing the idr reference to the release callback. To ensure that the device is not freed before calling iio_device_free the device_unregister call in iio_device_unregister is broken apart. iio_device_unregister will now only call device_del to remove the device from the system and iio_device_free will call put_device to drop the reference we obtained in iio_devce_alloc. We also have to take care that calling iio_device_free without having called iio_device_register still works (i.e. this can happen if something failed during device initialization). For this to work properly two minor changes were necessary: channel_attr_list needs to be initialized in iio_device_alloc and we have to check whether the chrdev has been registered before releasing it in iio_device_release. This change also brings iio_device_unregister and iio_device_free more in sync with iio_device_register and iio_device_alloc which call device_add and device_initialize respectively. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-04 08:41:42 +00:00
device_del(&indio_dev->dev);
}
EXPORT_SYMBOL(iio_device_unregister);
subsys_initcall(iio_init);
module_exit(iio_exit);
MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("Industrial I/O core");
MODULE_LICENSE("GPL");