iio: add reference to iio buffer on iio_dev_attr

This change adds a reference to a 'struct iio_buffer' object on the
iio_dev_attr object. This way, we can use the created iio_dev_attr objects
on per-buffer basis (since they're allocated anyway).

A minor downside of this change is that the number of parameters on
__iio_add_chan_devattr() grows by 1. This looks like it could do with a bit
of a re-think.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-14-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h
index 7d5b179..731f517 100644 (file)
--- a/drivers/iio/iio_core.h
+++ b/drivers/iio/iio_core.h
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/device.h>
 
+struct iio_buffer;
 struct iio_chan_spec;
 struct iio_dev;
 
@@ -43,6 +44,7 @@ int __iio_add_chan_devattr(const char *postfix,
                           u64 mask,
                           enum iio_shared_by shared_by,
                           struct device *dev,
+                          struct iio_buffer *buffer,
                           struct list_head *attr_list);
 void iio_free_chan_devattr_list(struct list_head *attr_list);
 

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 76f0f6a..e6edec3 100644 (file)
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -447,6 +447,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
                                     0,
                                     IIO_SEPARATE,
                                     &indio_dev->dev,
+                                    buffer,
                                     &buffer->scan_el_dev_attr_list);
        if (ret)
                return ret;
@@ -458,6 +459,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
                                     0,
                                     0,
                                     &indio_dev->dev,
+                                    buffer,
                                     &buffer->scan_el_dev_attr_list);
        if (ret)
                return ret;
@@ -470,6 +472,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
                                             chan->scan_index,
                                             0,
                                             &indio_dev->dev,
+                                            buffer,
                                             &buffer->scan_el_dev_attr_list);
        else
                ret = __iio_add_chan_devattr("en",
@@ -479,6 +482,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
                                             chan->scan_index,
                                             0,
                                             &indio_dev->dev,
+                                            buffer,
                                             &buffer->scan_el_dev_attr_list);
        if (ret)
                return ret;

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 924f3a1..f4e5a08 100644 (file)
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1116,6 +1116,7 @@ int __iio_add_chan_devattr(const char *postfix,
                           u64 mask,
                           enum iio_shared_by shared_by,
                           struct device *dev,
+                          struct iio_buffer *buffer,
                           struct list_head *attr_list)
 {
        int ret;
@@ -1131,6 +1132,7 @@ int __iio_add_chan_devattr(const char *postfix,
                goto error_iio_dev_attr_free;
        iio_attr->c = chan;
        iio_attr->address = mask;
+       iio_attr->buffer = buffer;
        list_for_each_entry(t, attr_list, l)
                if (strcmp(t->dev_attr.attr.name,
                           iio_attr->dev_attr.attr.name) == 0) {
@@ -1167,6 +1169,7 @@ static int iio_device_add_channel_label(struct iio_dev *indio_dev,
                                     0,
                                     IIO_SEPARATE,
                                     &indio_dev->dev,
+                                    NULL,
                                     &iio_dev_opaque->channel_attr_list);
        if (ret < 0)
                return ret;
@@ -1192,6 +1195,7 @@ static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
                                             i,
                                             shared_by,
                                             &indio_dev->dev,
+                                            NULL,
                                             &iio_dev_opaque->channel_attr_list);
                if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
                        continue;
@@ -1228,6 +1232,7 @@ static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
                                             i,
                                             shared_by,
                                             &indio_dev->dev,
+                                            NULL,
                                             &iio_dev_opaque->channel_attr_list);
                kfree(avail_postfix);
                if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
@@ -1324,6 +1329,7 @@ static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
                                        i,
                                        ext_info->shared,
                                        &indio_dev->dev,
+                                       NULL,
                                        &iio_dev_opaque->channel_attr_list);
                        i++;
                        if (ret == -EBUSY && ext_info->shared)

diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
index ea8947c..a30e289 100644 (file)
--- a/drivers/iio/industrialio-event.c
+++ b/drivers/iio/industrialio-event.c
@@ -385,6 +385,7 @@ static int iio_device_add_event(struct iio_dev *indio_dev,
 
                ret = __iio_add_chan_devattr(postfix, chan, show, store,
                         (i << 16) | spec_index, shared_by, &indio_dev->dev,
+                        NULL,
                        &iio_dev_opaque->event_interface->dev_attr_list);
                kfree(postfix);
 

diff --git a/include/linux/iio/sysfs.h b/include/linux/iio/sysfs.h
index b532c87..e51fba6 100644 (file)
--- a/include/linux/iio/sysfs.h
+++ b/include/linux/iio/sysfs.h
@@ -9,6 +9,7 @@
 #ifndef _INDUSTRIAL_IO_SYSFS_H_
 #define _INDUSTRIAL_IO_SYSFS_H_
 
+struct iio_buffer;
 struct iio_chan_spec;
 
 /**
@@ -17,12 +18,14 @@ struct iio_chan_spec;
  * @address:   associated register address
  * @l:         list head for maintaining list of dynamically created attrs
  * @c:         specification for the underlying channel
+ * @buffer:    the IIO buffer to which this attribute belongs to (if any)
  */
 struct iio_dev_attr {
        struct device_attribute dev_attr;
        u64 address;
        struct list_head l;
        struct iio_chan_spec const *c;
+       struct iio_buffer *buffer;
 };
 
 #define to_iio_dev_attr(_dev_attr)                             \