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From: Alexandru Ardelean <alexandru.ardelean@analog.com>
To: <linux-kernel@vger.kernel.org>, <linux-iio@vger.kernel.org>
Cc: <lars@metafoo.de>, <Michael.Hennerich@analog.com>,
	<jic23@kernel.org>, <nuno.sa@analog.com>,
	<dragos.bogdan@analog.com>,
	Alexandru Ardelean <alexandru.ardelean@analog.com>
Subject: [PATCH v2 06/12] iio: buffer: re-route scan_elements via it's kobj_type
Date: Fri, 22 Jan 2021 17:57:59 +0200	[thread overview]
Message-ID: <20210122155805.83012-7-alexandru.ardelean@analog.com> (raw)
In-Reply-To: <20210122155805.83012-1-alexandru.ardelean@analog.com>

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@analog.com>
---
 drivers/iio/iio_core.h            |   5 +
 drivers/iio/industrialio-buffer.c | 160 +++++++++++++++++++++++-------
 drivers/iio/industrialio-core.c   |   1 -
 3 files changed, 128 insertions(+), 38 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 628d78125126..524b897a1877 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) {
+		list_del(&p->l);
+		kfree(p->attr.name);
+		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 = {
@@ -1372,7 +1458,7 @@ 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;
@@ -1453,7 +1539,7 @@ 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)
@@ -1469,7 +1555,7 @@ 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:
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index b8f7261945f5..088e59042226 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -967,7 +967,6 @@ 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


  parent reply	other threads:[~2021-01-22 15:57 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-22 15:57 [PATCH v2 00/12] iio: core,buffer: add support for multiple IIO buffers per IIO device Alexandru Ardelean
2021-01-22 15:57 ` [PATCH v2 01/12] iio: core: register chardev only if needed Alexandru Ardelean
2021-01-22 15:57 ` [PATCH v2 02/12] iio: buffer: add back-ref from iio_buffer to iio_dev Alexandru Ardelean
2021-01-22 15:57 ` [PATCH v2 03/12] iio: buffer: rework buffer & scan_elements dir creation Alexandru Ardelean
2021-01-22 15:57 ` [PATCH v2 04/12] iio: buffer: add index to the first IIO buffer dir and symlink it back Alexandru Ardelean
2021-01-22 15:57 ` [PATCH v2 05/12] iio: core: split __iio_device_attr_init() to init only the attr object Alexandru Ardelean
2021-01-22 15:57 ` Alexandru Ardelean [this message]
2021-01-22 16:12   ` [PATCH v2 06/12] iio: buffer: re-route scan_elements via it's kobj_type Alexandru Ardelean
2021-01-22 15:58 ` [PATCH v2 07/12] iio: buffer: re-route core buffer attributes via it's new kobj_type Alexandru Ardelean
2021-01-22 15:58 ` [PATCH v2 08/12] iio: buffer: add helper to get the IIO device to which a buffer belongs Alexandru Ardelean
2021-01-22 15:58 ` [PATCH v2 09/12] iio: re-route all buffer attributes through new buffer kobj_type Alexandru Ardelean
2021-01-22 15:58 ` [PATCH v2 10/12] iio: core: wrap iio device & buffer into struct for character devices Alexandru Ardelean
2021-01-22 15:58 ` [PATCH v2 11/12] iio: buffer: introduce support for attaching more IIO buffers Alexandru Ardelean
2021-01-22 15:58 ` [PATCH v2 12/12] iio: buffer: add ioctl() to support opening extra buffers for IIO device Alexandru Ardelean

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