iio: buffer: wrap all buffer attributes into iio_dev_attr

This change wraps all buffer attributes into iio_dev_attr objects, and
assigns a reference to the IIO buffer they belong to.

With the addition of multiple IIO buffers per one IIO device, we need a way
to know which IIO buffer is being enabled/disabled/controlled.

We know that all buffer attributes are device_attributes. So we can wrap
them with a iio_dev_attr types. In the iio_dev_attr type, we can also hold
a reference to an IIO buffer.
So, we end up being able to allocate wrapped attributes for all buffer
attributes (even the one from other drivers).

The neat part with this mechanism, is that we don't need to add any extra
cleanup, because these attributes are being added to a dynamic list that
will get cleaned up via iio_free_chan_devattr_list().

With this change, the 'buffer->scan_el_dev_attr_list' list is being renamed
to 'buffer->buffer_attr_list', effectively merging (or finalizing the
merge) of the buffer/ & scan_elements/ attributes internally.

Accessing these new buffer attributes can now be done via
'to_iio_dev_attr(attr)->buffer' inside the show/store handlers.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-15-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Alexandru Ardelean 2021-02-15 12:40:33 +02:00 committed by Jonathan Cameron
parent 3e3d11b2e4
commit 15097c7a1a
3 changed files with 54 additions and 29 deletions

View File

@ -253,8 +253,7 @@ static ssize_t iio_scan_el_show(struct device *dev,
char *buf) char *buf)
{ {
int ret; int ret;
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
struct iio_buffer *buffer = indio_dev->buffer;
/* Ensure ret is 0 or 1. */ /* Ensure ret is 0 or 1. */
ret = !!test_bit(to_iio_dev_attr(attr)->address, ret = !!test_bit(to_iio_dev_attr(attr)->address,
@ -367,8 +366,8 @@ static ssize_t iio_scan_el_store(struct device *dev,
int ret; int ret;
bool state; bool state;
struct iio_dev *indio_dev = dev_to_iio_dev(dev); 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); struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
struct iio_buffer *buffer = this_attr->buffer;
ret = strtobool(buf, &state); ret = strtobool(buf, &state);
if (ret < 0) if (ret < 0)
@ -402,8 +401,7 @@ static ssize_t iio_scan_el_ts_show(struct device *dev,
struct device_attribute *attr, struct device_attribute *attr,
char *buf) char *buf)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
struct iio_buffer *buffer = indio_dev->buffer;
return sprintf(buf, "%d\n", buffer->scan_timestamp); return sprintf(buf, "%d\n", buffer->scan_timestamp);
} }
@ -415,7 +413,7 @@ static ssize_t iio_scan_el_ts_store(struct device *dev,
{ {
int ret; int ret;
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer; struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
bool state; bool state;
ret = strtobool(buf, &state); ret = strtobool(buf, &state);
@ -448,7 +446,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
IIO_SEPARATE, IIO_SEPARATE,
&indio_dev->dev, &indio_dev->dev,
buffer, buffer,
&buffer->scan_el_dev_attr_list); &buffer->buffer_attr_list);
if (ret) if (ret)
return ret; return ret;
attrcount++; attrcount++;
@ -460,7 +458,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
0, 0,
&indio_dev->dev, &indio_dev->dev,
buffer, buffer,
&buffer->scan_el_dev_attr_list); &buffer->buffer_attr_list);
if (ret) if (ret)
return ret; return ret;
attrcount++; attrcount++;
@ -473,7 +471,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
0, 0,
&indio_dev->dev, &indio_dev->dev,
buffer, buffer,
&buffer->scan_el_dev_attr_list); &buffer->buffer_attr_list);
else else
ret = __iio_add_chan_devattr("en", ret = __iio_add_chan_devattr("en",
chan, chan,
@ -483,7 +481,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
0, 0,
&indio_dev->dev, &indio_dev->dev,
buffer, buffer,
&buffer->scan_el_dev_attr_list); &buffer->buffer_attr_list);
if (ret) if (ret)
return ret; return ret;
attrcount++; attrcount++;
@ -495,8 +493,7 @@ static ssize_t iio_buffer_read_length(struct device *dev,
struct device_attribute *attr, struct device_attribute *attr,
char *buf) char *buf)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
struct iio_buffer *buffer = indio_dev->buffer;
return sprintf(buf, "%d\n", buffer->length); return sprintf(buf, "%d\n", buffer->length);
} }
@ -506,7 +503,7 @@ static ssize_t iio_buffer_write_length(struct device *dev,
const char *buf, size_t len) const char *buf, size_t len)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer; struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
unsigned int val; unsigned int val;
int ret; int ret;
@ -538,8 +535,7 @@ static ssize_t iio_buffer_show_enable(struct device *dev,
struct device_attribute *attr, struct device_attribute *attr,
char *buf) char *buf)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
struct iio_buffer *buffer = indio_dev->buffer;
return sprintf(buf, "%d\n", iio_buffer_is_active(buffer)); return sprintf(buf, "%d\n", iio_buffer_is_active(buffer));
} }
@ -1154,7 +1150,7 @@ static ssize_t iio_buffer_store_enable(struct device *dev,
int ret; int ret;
bool requested_state; bool requested_state;
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer; struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
bool inlist; bool inlist;
ret = strtobool(buf, &requested_state); ret = strtobool(buf, &requested_state);
@ -1183,8 +1179,7 @@ static ssize_t iio_buffer_show_watermark(struct device *dev,
struct device_attribute *attr, struct device_attribute *attr,
char *buf) char *buf)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
struct iio_buffer *buffer = indio_dev->buffer;
return sprintf(buf, "%u\n", buffer->watermark); return sprintf(buf, "%u\n", buffer->watermark);
} }
@ -1195,7 +1190,7 @@ static ssize_t iio_buffer_store_watermark(struct device *dev,
size_t len) size_t len)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer; struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
unsigned int val; unsigned int val;
int ret; int ret;
@ -1228,8 +1223,7 @@ static ssize_t iio_dma_show_data_available(struct device *dev,
struct device_attribute *attr, struct device_attribute *attr,
char *buf) char *buf)
{ {
struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
struct iio_buffer *buffer = indio_dev->buffer;
return sprintf(buf, "%zu\n", iio_buffer_data_available(buffer)); return sprintf(buf, "%zu\n", iio_buffer_data_available(buffer));
} }
@ -1254,6 +1248,27 @@ static struct attribute *iio_buffer_attrs[] = {
&dev_attr_data_available.attr, &dev_attr_data_available.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);
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, static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,
struct attribute **buffer_attrs, struct attribute **buffer_attrs,
int buffer_attrcount, int buffer_attrcount,
@ -1329,7 +1344,7 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
} }
scan_el_attrcount = 0; scan_el_attrcount = 0;
INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list); INIT_LIST_HEAD(&buffer->buffer_attr_list);
channels = indio_dev->channels; channels = indio_dev->channels;
if (channels) { if (channels) {
/* new magic */ /* new magic */
@ -1376,9 +1391,19 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs); buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs);
attrn = buffer_attrcount; for (i = 0; i < buffer_attrcount; i++) {
struct attribute *wrapped;
list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l) wrapped = iio_buffer_wrap_attr(buffer, attr[i]);
if (!wrapped) {
ret = -ENOMEM;
goto error_free_scan_mask;
}
attr[i] = wrapped;
}
attrn = 0;
list_for_each_entry(p, &buffer->buffer_attr_list, l)
attr[attrn++] = &p->dev_attr.attr; attr[attrn++] = &p->dev_attr.attr;
buffer->buffer_group.name = kasprintf(GFP_KERNEL, "buffer%d", index); buffer->buffer_group.name = kasprintf(GFP_KERNEL, "buffer%d", index);
@ -1412,7 +1437,7 @@ error_free_buffer_attrs:
error_free_scan_mask: error_free_scan_mask:
bitmap_free(buffer->scan_mask); bitmap_free(buffer->scan_mask);
error_cleanup_dynamic: error_cleanup_dynamic:
iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); iio_free_chan_devattr_list(&buffer->buffer_attr_list);
return ret; return ret;
} }
@ -1443,7 +1468,7 @@ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer)
bitmap_free(buffer->scan_mask); bitmap_free(buffer->scan_mask);
kfree(buffer->buffer_group.name); kfree(buffer->buffer_group.name);
kfree(buffer->buffer_group.attrs); kfree(buffer->buffer_group.attrs);
iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); iio_free_chan_devattr_list(&buffer->buffer_attr_list);
} }
void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev)

View File

@ -1357,7 +1357,7 @@ void iio_free_chan_devattr_list(struct list_head *attr_list)
struct iio_dev_attr *p, *n; struct iio_dev_attr *p, *n;
list_for_each_entry_safe(p, n, attr_list, l) { list_for_each_entry_safe(p, n, attr_list, l) {
kfree(p->dev_attr.attr.name); kfree_const(p->dev_attr.attr.name);
list_del(&p->l); list_del(&p->l);
kfree(p); kfree(p);
} }

View File

@ -97,8 +97,8 @@ struct iio_buffer {
/* @scan_timestamp: Does the scan mode include a timestamp. */ /* @scan_timestamp: Does the scan mode include a timestamp. */
bool scan_timestamp; bool scan_timestamp;
/* @scan_el_dev_attr_list: List of scan element related attributes. */ /* @buffer_attr_list: List of buffer attributes. */
struct list_head scan_el_dev_attr_list; struct list_head buffer_attr_list;
/* /*
* @buffer_group: Attributes of the new buffer group. * @buffer_group: Attributes of the new buffer group.