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Date: Tue, 17 Nov 2020 18:23:34 +0200
From: Alexandru Ardelean <alexandru.ardelean@...log.com>
To: <linux-iio@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC: <lars@...afoo.de>, <jic23@...nel.org>,
Alexandru Ardelean <alexandru.ardelean@...log.com>
Subject: [RFC PATCH 06/12] iio: buffer: re-route scan_elements via it's kobj_type
The scan_elements attributes are solely located inside
'industrialio-buffer-sysfs.c'. In order to support more than one buffer per
IIO device, we need to expand scan_elements attributes directly to IIO
buffer object, and not the IIO device.
This also requires that a new 'iio_buffer_attr' type be added which is
mostly a copy of 'iio_dev_attr', but this expands to an IIO buffer object.
The 'iio_dev_attr' type could have been re-used here, but managing 'device'
objects is a bit more tricky (than it looks at first). A 'device' object
needs to be initialized & managed and we only need to the 'kobj' to expand
from the 'bufferX' directory back to an IIO buffer.
kobjects are simpler to manage.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@...log.com>
---
drivers/iio/iio_core.h | 5 +
drivers/iio/industrialio-buffer.c | 162 +++++++++++++++++++++++-------
drivers/iio/industrialio-core.c | 1 -
3 files changed, 129 insertions(+), 39 deletions(-)
diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h
index fced02cadcc3..43d44ec92781 100644
--- a/drivers/iio/iio_core.h
+++ b/drivers/iio/iio_core.h
@@ -31,6 +31,11 @@ void iio_device_ioctl_handler_register(struct iio_dev *indio_dev,
struct iio_ioctl_handler *h);
void iio_device_ioctl_handler_unregister(struct iio_ioctl_handler *h);
+int iio_attr_init(struct attribute *attr,
+ const char *postfix,
+ struct iio_chan_spec const *chan,
+ enum iio_shared_by shared_by);
+
int __iio_add_chan_devattr(const char *postfix,
struct iio_chan_spec const *chan,
ssize_t (*func)(struct device *dev,
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 62c8bd6b67cd..445709ef245c 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -26,6 +26,26 @@
#include <linux/iio/buffer.h>
#include <linux/iio/buffer_impl.h>
+/**
+ * struct iio_buf_attr - iio buffer specific attribute
+ * @attr: underlying attribute
+ * @address: associated register address
+ * @l: list head for maintaining list of dynamically created attrs
+ * @c: specification for the underlying channel
+ * @show: sysfs show hook for this attribute
+ * @store: sysfs store hook for this attribute
+ */
+struct iio_buf_attr {
+ struct attribute attr;
+ u64 address;
+ struct list_head l;
+ struct iio_chan_spec const *c;
+ ssize_t (*show)(struct iio_buffer *buffer, struct iio_buf_attr *attr,
+ char *buf);
+ ssize_t (*store)(struct iio_buffer *buffer, struct iio_buf_attr *attr,
+ const char *buf, size_t count);
+};
+
static const char * const iio_endian_prefix[] = {
[IIO_BE] = "be",
[IIO_LE] = "le",
@@ -210,18 +230,17 @@ void iio_buffer_init(struct iio_buffer *buffer)
}
EXPORT_SYMBOL(iio_buffer_init);
-static ssize_t iio_show_scan_index(struct device *dev,
- struct device_attribute *attr,
+static ssize_t iio_show_scan_index(struct iio_buffer *buffer,
+ struct iio_buf_attr *attr,
char *buf)
{
- return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
+ return sprintf(buf, "%u\n", attr->c->scan_index);
}
-static ssize_t iio_show_fixed_type(struct device *dev,
- struct device_attribute *attr,
+static ssize_t iio_show_fixed_type(struct iio_buffer *buffer,
+ struct iio_buf_attr *this_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) {
@@ -248,17 +267,14 @@ static ssize_t iio_show_fixed_type(struct device *dev,
this_attr->c->scan_type.shift);
}
-static ssize_t iio_scan_el_show(struct device *dev,
- struct device_attribute *attr,
+static ssize_t iio_scan_el_show(struct iio_buffer *buffer,
+ struct iio_buf_attr *attr,
char *buf)
{
int ret;
- struct iio_dev *indio_dev = dev_to_iio_dev(dev);
- struct iio_buffer *buffer = indio_dev->buffer;
/* Ensure ret is 0 or 1. */
- ret = !!test_bit(to_iio_dev_attr(attr)->address,
- buffer->scan_mask);
+ ret = !!test_bit(attr->address, buffer->scan_mask);
return sprintf(buf, "%d\n", ret);
}
@@ -359,16 +375,14 @@ static int iio_scan_mask_query(struct iio_dev *indio_dev,
return !!test_bit(bit, buffer->scan_mask);
};
-static ssize_t iio_scan_el_store(struct device *dev,
- struct device_attribute *attr,
+static ssize_t iio_scan_el_store(struct iio_buffer *buffer,
+ struct iio_buf_attr *this_attr,
const char *buf,
size_t len)
{
+ struct iio_dev *indio_dev = buffer->indio_dev;
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)
@@ -398,24 +412,20 @@ static ssize_t iio_scan_el_store(struct device *dev,
}
-static ssize_t iio_scan_el_ts_show(struct device *dev,
- struct device_attribute *attr,
+static ssize_t iio_scan_el_ts_show(struct iio_buffer *buffer,
+ struct iio_buf_attr *attr,
char *buf)
{
- struct iio_dev *indio_dev = dev_to_iio_dev(dev);
- struct iio_buffer *buffer = indio_dev->buffer;
-
return sprintf(buf, "%d\n", buffer->scan_timestamp);
}
-static ssize_t iio_scan_el_ts_store(struct device *dev,
- struct device_attribute *attr,
+static ssize_t iio_scan_el_ts_store(struct iio_buffer *buffer,
+ struct iio_buf_attr *attr,
const char *buf,
size_t len)
{
+ struct iio_dev *indio_dev = buffer->indio_dev;
int ret;
- struct iio_dev *indio_dev = dev_to_iio_dev(dev);
- struct iio_buffer *buffer = indio_dev->buffer;
bool state;
ret = strtobool(buf, &state);
@@ -434,13 +444,88 @@ static ssize_t iio_scan_el_ts_store(struct device *dev,
return ret ? ret : len;
}
+static int __iio_add_chan_bufattr(const char *postfix,
+ struct iio_chan_spec const *chan,
+ ssize_t (*readfunc)(struct iio_buffer *buffer,
+ struct iio_buf_attr *attr,
+ char *buf),
+ ssize_t (*writefunc)(struct iio_buffer *buffer,
+ struct iio_buf_attr *attr,
+ const char *buf,
+ size_t len),
+ u64 mask,
+ enum iio_shared_by shared_by,
+ struct device *dev,
+ struct list_head *attr_list)
+{
+ struct iio_buf_attr *iio_attr, *t;
+ int ret;
+
+ iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
+ if (iio_attr == NULL)
+ return -ENOMEM;
+
+ ret = iio_attr_init(&iio_attr->attr, postfix, chan, shared_by);
+ if (ret)
+ goto error_iio_buf_attr_free;
+
+ iio_attr->c = chan;
+ iio_attr->address = mask;
+ list_for_each_entry(t, attr_list, l) {
+ if (strcmp(t->attr.name, iio_attr->attr.name) == 0) {
+ if (shared_by == IIO_SEPARATE)
+ dev_err(dev, "tried to double register : %s\n",
+ t->attr.name);
+ ret = -EBUSY;
+ goto error_iio_buf_attr_deinit;
+ }
+ }
+ list_add(&iio_attr->l, attr_list);
+
+ if (readfunc) {
+ iio_attr->attr.mode |= S_IRUGO;
+ iio_attr->show = readfunc;
+ }
+
+ if (writefunc) {
+ iio_attr->attr.mode |= S_IWUSR;
+ iio_attr->store = writefunc;
+ }
+
+ return 0;
+
+error_iio_buf_attr_deinit:
+ kfree(iio_attr->attr.name);
+error_iio_buf_attr_free:
+ kfree(iio_attr);
+ return ret;
+}
+
+/**
+ * iio_free_chan_bufattr_list() - Free a list of IIO buffer attributes
+ * @attr_list: List of IIO buffer attributes
+ *
+ * This function frees the memory allocated for each of the IIO buffer
+ * attributes in the list.
+ */
+static void iio_free_chan_bufattr_list(struct list_head *attr_list)
+{
+ struct iio_buf_attr *p, *n;
+
+ list_for_each_entry_safe(p, n, attr_list, l) {
+ kfree(p->attr.name);
+ list_del(&p->l);
+ kfree(p);
+ }
+}
+
static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
struct iio_buffer *buffer,
const struct iio_chan_spec *chan)
{
int ret, attrcount = 0;
- ret = __iio_add_chan_devattr("index",
+ ret = __iio_add_chan_bufattr("index",
chan,
&iio_show_scan_index,
NULL,
@@ -451,7 +536,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
if (ret)
return ret;
attrcount++;
- ret = __iio_add_chan_devattr("type",
+ ret = __iio_add_chan_bufattr("type",
chan,
&iio_show_fixed_type,
NULL,
@@ -463,7 +548,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
return ret;
attrcount++;
if (chan->type != IIO_TIMESTAMP)
- ret = __iio_add_chan_devattr("en",
+ ret = __iio_add_chan_bufattr("en",
chan,
&iio_scan_el_show,
&iio_scan_el_store,
@@ -472,7 +557,7 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
else
- ret = __iio_add_chan_devattr("en",
+ ret = __iio_add_chan_bufattr("en",
chan,
&iio_scan_el_ts_show,
&iio_scan_el_ts_store,
@@ -1251,6 +1336,7 @@ static struct attribute *iio_buffer_attrs[] = {
};
#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
+#define to_iio_buf_attr(_attr) container_of(_attr, struct iio_buf_attr, attr)
static ssize_t iio_buffer_dir_attr_show(struct kobject *kobj,
struct attribute *attr,
@@ -1291,9 +1377,9 @@ static ssize_t iio_scan_el_dir_attr_show(struct kobject *kobj,
char *buf)
{
struct iio_buffer *buffer = container_of(kobj, struct iio_buffer, scan_el_dir);
- struct device_attribute *dattr = to_dev_attr(attr);
+ struct iio_buf_attr *battr = to_iio_buf_attr(attr);
- return dattr->show(&buffer->indio_dev->dev, dattr, buf);
+ return battr->show(buffer, battr, buf);
}
static ssize_t iio_scan_el_dir_attr_store(struct kobject *kobj,
@@ -1302,9 +1388,9 @@ static ssize_t iio_scan_el_dir_attr_store(struct kobject *kobj,
size_t len)
{
struct iio_buffer *buffer = container_of(kobj, struct iio_buffer, scan_el_dir);
- struct device_attribute *dattr = to_dev_attr(attr);
+ struct iio_buf_attr *battr = to_iio_buf_attr(attr);
- return dattr->store(&buffer->indio_dev->dev, dattr, buf, len);
+ return battr->store(buffer, battr, buf, len);
}
static const struct sysfs_ops iio_scan_el_dir_sysfs_ops = {
@@ -1349,7 +1435,7 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
struct iio_dev *indio_dev,
unsigned int idx)
{
- struct iio_dev_attr *p;
+ struct iio_buf_attr *p;
struct attribute **attr;
int ret, i, attrn, attrcount;
const struct iio_chan_spec *channels;
@@ -1430,7 +1516,7 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
attrn = 0;
list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
- buffer->scan_el_attrs[attrn++] = &p->dev_attr.attr;
+ buffer->scan_el_attrs[attrn++] = &p->attr;
ret = iio_sysfs_add_attrs(&buffer->scan_el_dir, buffer->scan_el_attrs);
if (ret)
@@ -1446,7 +1532,7 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
bitmap_free(buffer->scan_mask);
error_cleanup_dynamic:
iio_sysfs_del_attrs(&buffer->buffer_dir, buffer->buffer_attrs);
- iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
+ iio_free_chan_bufattr_list(&buffer->scan_el_dev_attr_list);
error_buffer_kobject_put:
kobject_put(&buffer->buffer_dir);
error_buffer_free_attrs:
@@ -1507,7 +1593,7 @@ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer)
kfree(buffer->scan_el_attrs);
bitmap_free(buffer->scan_mask);
iio_sysfs_del_attrs(&buffer->buffer_dir, buffer->buffer_attrs);
- iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
+ iio_free_chan_bufattr_list(&buffer->scan_el_dev_attr_list);
kobject_put(&buffer->buffer_dir);
kfree(buffer->buffer_attrs);
}
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index e9aa84f5b05a..28830e87e8cb 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -972,7 +972,6 @@ static ssize_t iio_write_channel_info(struct device *dev,
return len;
}
-static
int iio_attr_init(struct attribute *attr,
const char *postfix,
struct iio_chan_spec const *chan,
--
2.17.1
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