Commit d9a62574 authored by Alexandru Ardelean's avatar Alexandru Ardelean Committed by Jonathan Cameron
Browse files

iio: core: merge buffer/ & scan_elements/ attributes 



With this change, we create a new directory for the IIO device called
buffer0, under which both the old buffer/ and scan_elements/ are stored.

This is done to simplify the addition of multiple IIO buffers per IIO
device. Otherwise we would need to add a bufferX/ and scan_elementsX/
directory for each IIO buffer.
With the current way of storing attribute groups, we can't have directories
stored under each other (i.e. scan_elements/ under buffer/), so the best
approach moving forward is to merge their attributes.

The old/legacy buffer/ & scan_elements/ groups are not stored on the opaque
IIO device object. This way the IIO buffer can have just a single
attribute_group object, saving a bit of memory when adding multiple IIO
buffers.

Signed-off-by: default avatarAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-13-alexandru.ardelean@analog.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent e2b4d7ac

drivers/iio/industrialio-buffer.c

+88 −27
Original line number Diff line number Diff line
@@ -1175,8 +1175,6 @@ static ssize_t iio_buffer_store_enable(struct device *dev, 
	return (ret < 0) ? ret : len;

}



static const char * const iio_scan_elements_group_name = "scan_elements";



static ssize_t iio_buffer_show_watermark(struct device *dev,

					 struct device_attribute *attr,

					 char *buf)
@@ -1252,8 +1250,68 @@ static struct attribute *iio_buffer_attrs[] = { 
	&dev_attr_data_available.attr,

};



static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,

						   struct attribute **buffer_attrs,

						   int buffer_attrcount,

						   int scan_el_attrcount)

{

	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);

	struct attribute_group *group;

	struct attribute **attrs;

	int ret;



	attrs = kcalloc(buffer_attrcount + 1, sizeof(*attrs), GFP_KERNEL);

	if (!attrs)

		return -ENOMEM;



	memcpy(attrs, buffer_attrs, buffer_attrcount * sizeof(*attrs));



	group = &iio_dev_opaque->legacy_buffer_group;

	group->attrs = attrs;

	group->name = "buffer";



	ret = iio_device_register_sysfs_group(indio_dev, group);

	if (ret)

		goto error_free_buffer_attrs;



	attrs = kcalloc(scan_el_attrcount + 1, sizeof(*attrs), GFP_KERNEL);

	if (!attrs) {

		ret = -ENOMEM;

		goto error_free_buffer_attrs;

	}



	memcpy(attrs, &buffer_attrs[buffer_attrcount],

	       scan_el_attrcount * sizeof(*attrs));



	group = &iio_dev_opaque->legacy_scan_el_group;

	group->attrs = attrs;

	group->name = "scan_elements";



	ret = iio_device_register_sysfs_group(indio_dev, group);

	if (ret)

		goto error_free_scan_el_attrs;



	return 0;



error_free_buffer_attrs:

	kfree(iio_dev_opaque->legacy_buffer_group.attrs);

error_free_scan_el_attrs:

	kfree(iio_dev_opaque->legacy_scan_el_group.attrs);



	return ret;

}



static void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev)

{

	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);



	kfree(iio_dev_opaque->legacy_buffer_group.attrs);

	kfree(iio_dev_opaque->legacy_scan_el_group.attrs);

}



static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,

					     struct iio_dev *indio_dev)

					     struct iio_dev *indio_dev,

					     int index)

{

	struct iio_dev_attr *p;

	struct attribute **attr;
@@ -1294,8 +1352,8 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, 
		}

	}



	attr = kcalloc(buffer_attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1,

		       sizeof(*attr), GFP_KERNEL);

	attrn = buffer_attrcount + scan_el_attrcount + ARRAY_SIZE(iio_buffer_attrs);

	attr = kcalloc(attrn + 1, sizeof(* attr), GFP_KERNEL);

	if (!attr) {

		ret = -ENOMEM;

		goto error_free_scan_mask;
@@ -1313,37 +1371,38 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, 
		       sizeof(struct attribute *) * buffer_attrcount);



	buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs);

	attr[buffer_attrcount] = NULL;



	buffer->buffer_group.name = "buffer";

	buffer->buffer_group.attrs = attr;

	attrn = buffer_attrcount;



	ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group);

	if (ret)

		goto error_free_buffer_attrs;



	buffer->scan_el_group.name = iio_scan_elements_group_name;

	list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)

		attr[attrn++] = &p->dev_attr.attr;



	buffer->scan_el_group.attrs = kcalloc(scan_el_attrcount + 1,

					      sizeof(buffer->scan_el_group.attrs[0]),

					      GFP_KERNEL);

	if (buffer->scan_el_group.attrs == NULL) {

	buffer->buffer_group.name = kasprintf(GFP_KERNEL, "buffer%d", index);

	if (!buffer->buffer_group.name) {

		ret = -ENOMEM;

		goto error_free_scan_mask;

		goto error_free_buffer_attrs;

	}

	attrn = 0;



	list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)

		buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;

	buffer->buffer_group.attrs = attr;



	ret = iio_device_register_sysfs_group(indio_dev, &buffer->scan_el_group);

	ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group);

	if (ret)

		goto error_free_scan_el_attrs;

		goto error_free_buffer_attr_group_name;



	/* we only need to register the legacy groups for the first buffer */

	if (index > 0)

		return 0;



error_free_scan_el_attrs:

	kfree(buffer->scan_el_group.attrs);

	ret = iio_buffer_register_legacy_sysfs_groups(indio_dev, attr,

						      buffer_attrcount,

						      scan_el_attrcount);

	if (ret)

		goto error_free_buffer_attr_group_name;



	return 0;



error_free_buffer_attr_group_name:

	kfree(buffer->buffer_group.name);

error_free_buffer_attrs:

	kfree(buffer->buffer_group.attrs);

error_free_scan_mask:
@@ -1372,14 +1431,14 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) 
	if (!buffer)

		return 0;



	return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev);

	return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0);

}



static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer)

{

	bitmap_free(buffer->scan_mask);

	kfree(buffer->buffer_group.name);

	kfree(buffer->buffer_group.attrs);

	kfree(buffer->scan_el_group.attrs);

	iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);

}
@@ -1390,6 +1449,8 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) 
	if (!buffer)

		return;



	iio_buffer_unregister_legacy_sysfs_groups(indio_dev);



	__iio_buffer_free_sysfs_and_mask(buffer);

}

include/linux/iio/buffer_impl.h

+3 −6
Original line number Diff line number Diff line
@@ -100,14 +100,11 @@ struct iio_buffer { 
	/* @scan_el_dev_attr_list: List of scan element related attributes. */

	struct list_head scan_el_dev_attr_list;



	/* @buffer_group: Attributes of the buffer group. */

	struct attribute_group buffer_group;



	/*

	 * @scan_el_group: Attribute group for those attributes not

	 * created from the iio_chan_info array.

	 * @buffer_group: Attributes of the new buffer group.

	 * Includes scan elements attributes.

	 */

	struct attribute_group scan_el_group;

	struct attribute_group buffer_group;



	/* @attrs: Standard attributes of the buffer. */

	const struct attribute **attrs;

include/linux/iio/iio-opaque.h

+4 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 
 * @ioctl_handlers:		ioctl handlers registered with the core handler

 * @groups:			attribute groups

 * @groupcounter:		index of next attribute group

 * @legacy_scan_el_group:	attribute group for legacy scan elements attribute group

 * @legacy_buffer_group:	attribute group for legacy buffer attributes group

 * @debugfs_dentry:		device specific debugfs dentry

 * @cached_reg_addr:		cached register address for debugfs reads

 * @read_buf:			read buffer to be used for the initial reg read
@@ -28,6 +30,8 @@ struct iio_dev_opaque { 
	struct list_head		ioctl_handlers;

	const struct attribute_group	**groups;

	int				groupcounter;

	struct attribute_group		legacy_scan_el_group;

	struct attribute_group		legacy_buffer_group;

#if defined(CONFIG_DEBUG_FS)

	struct dentry			*debugfs_dentry;

	unsigned			cached_reg_addr;