[PATCH v5 00/13] ACPI graph support

[PATCH v5 00/13] ACPI graph support

[Sakari Ailus]

Hello everyone,

This is the fifth version of the ACPI graph support patchset.

The previous RFC version of the set is available here:

<URL:http://www.spinics.net/lists/linux-acpi/msg69547.html> 

There are also v1, v2, v3 and v4 which can be found here:

<URL:http://www.spinics.net/lists/linux-acpi/msg71661.html>
<URL:http://www.spinics.net/lists/linux-acpi/msg71809.html>
<URL:http://www.spinics.net/lists/linux-acpi/msg72171.html>
<URL:http://www.spinics.net/lists/linux-acpi/msg72346.html>

This set contains patches written by Mika Westerberg and by myself. The 
patchset brings support for graphs to ACPI. The functionality achieved by 
these patches is very similar to what the Device tree provides: the port
and the endpoint concept are being employed. The patches make use of the
_DSD property and data extensions to achieve this. The fwnode interface is
extended by graph functionality; this way graph information originating 
from both OF and ACPI may be accessed using the same interface, without 
being aware of the underlying firmware interface. 

The last patch of the set contains ASL documentation including an example.

The entire set may also be found here (on mediatree.git master, but it
also applies cleanly on linux-next):

<URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=acpi-graph> 

The resulting fwnode graph interface has been tested using V4L2 async with
fwnode matching and smiapp and omap3isp drivers, with appropriate changes 
to make use of the fwnode interface in drivers.

I'm additionally moving the firmware implementation specific code from
drivers/base/property.c to firmware specific locations. I'll post that
patchset soon. It'll be available here:

<URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=acpi-graph-cleaned>

The V4L2 patches can be found here. The fwnode graph interface is used by 
the newly added V4L2 fwnode framework which replaces the V4L2 OF
framework, with equivalent functionality. 

<URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=v4l2-acpi>

changes since v4:

- Use port and endpoint numbers in references. This is more reliable, as
  the port and endpoint numbers are more stable than their location in the
  data extension array. Because of this, also require the "endpoint"
  property to be there. The documentation (the last patch) is changed
  accordingly.

- Move dev_fwnode() implementation back to property.c where it was.
  EXPORT_SYMBOL_GPL() it, and add a prototype in include/linux/property.h.
  This removes the need for patches "[PATCH v4 10/16] irqchip/gic: Add
  missing forward declaration for struct device" and "of: No need to
  include linux/property.h, linux/fwnode.h is sufficient".

- Fix fwnode_graph_parse_endpoint() KernelDoc documentation.

- Add documentation for struct fwnode_endpoint.

- Removed patch "[PATCH v4 09/16] driver core: Arrange headers
  alphabetically" from the set.

changes since v3:

- Rebase on current PM tree including 4.11-rc1 merge --- there were a few
  conflicts.

changes since v2.2:

- Drop device_fwnode_handle() function in favour of moving the existing
  dev_fwnode() function from drivers/base/property.c to linux/property.h
  (now patch 12).

- Unmerge two unrelated patches accidentally merged between RFC v1 and
  PATCH v1 of the series. The patch adding device_fwnode_handle() was
  accidentally merged with "device property: Obtain device's fwnode
  independently of FW type".

- Remove redundant forward declaration of struct device in
  linux/property.h.

changes since v2:

- Include linux/property.h for property fwnode API in additional drivers
  (current patch 11).

changes since v1: 

- Fix a few checkpatch.pl warnings in Mika's patches (too long lines),

- remove the "endpoint" property specifying the endpoint id. The endpoint 
id is a software concept and the index in the endpoint array can be used
instead if needed. The changes are in patches "device property: Add 
support for fwnode endpoints" and "ACPI / DSD: Document references, 
ports and endpoints" and

- add patch "irqchip/gic: Add missing forward declaration for 
struct device" (patch 9) to fix compilation warning on arm64 caused 
by "of: No need to include linux/property.h, linux/fwnode.h is
sufficient" (now patch 10)

changes since RFC v1: 

- Rebased the set --- there were a few conflicts. 

- Fixed a bug in ACPI graph parsing. (Thanks to Mika!)

- Remove one layer (the "ports" node) of the _DSD hierarchical data 
structure. Change the documentation accordingly. Instead, rely on the 
presence of "port" and "endpoint" properties to identify port and 
endpoint nodes. 

- Add a reference the DSD property rule document [1].

-- 
Kind regards,
Sakari

[PATCH v5 01/13] ACPI / property: Add possiblity to retrieve parent firmware node

[Sakari Ailus]

From: Mika Westerberg <mika.westerberg@linux.intel.com>

Sometimes it is useful to be able to navigate firmware node hierarchy
upwards toward parent nodes. ACPI device nodes are pretty much already
supported because ACPICA provides acpi_get_parent(). ACPI data nodes,
however, are all below the same parent ACPI device. Their hierarchy is
created by "linking" each other using references in the value field.

Add parent pointer to the parent data node while we create them so it is
easy to navigate the hierarchy backwards. We use this parent pointer in a
new function acpi_node_get_parent() that is able to extract parent of both
ACPI firmware node types.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/acpi/property.c | 72 ++++++++++++++++++++++++++++++++++++++-----------
 include/acpi/acpi_bus.h |  1 +
 include/linux/acpi.h    |  7 +++++
 3 files changed, 65 insertions(+), 15 deletions(-)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 3afddcd..587c9d0 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -37,14 +37,16 @@ static const u8 ads_uuid[16] = {
 
 static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
 					   const union acpi_object *desc,
-					   struct acpi_device_data *data);
+					   struct acpi_device_data *data,
+					   struct fwnode_handle *parent);
 static bool acpi_extract_properties(const union acpi_object *desc,
 				    struct acpi_device_data *data);
 
 static bool acpi_nondev_subnode_extract(const union acpi_object *desc,
 					acpi_handle handle,
 					const union acpi_object *link,
-					struct list_head *list)
+					struct list_head *list,
+					struct fwnode_handle *parent)
 {
 	struct acpi_data_node *dn;
 	bool result;
@@ -55,6 +57,7 @@ static bool acpi_nondev_subnode_extract(const union acpi_object *desc,
 
 	dn->name = link->package.elements[0].string.pointer;
 	dn->fwnode.type = FWNODE_ACPI_DATA;
+	dn->parent = parent;
 	INIT_LIST_HEAD(&dn->data.subnodes);
 
 	result = acpi_extract_properties(desc, &dn->data);
@@ -71,9 +74,11 @@ static bool acpi_nondev_subnode_extract(const union acpi_object *desc,
 		 */
 		status = acpi_get_parent(handle, &scope);
 		if (ACPI_SUCCESS(status)
-		    && acpi_enumerate_nondev_subnodes(scope, desc, &dn->data))
+		    && acpi_enumerate_nondev_subnodes(scope, desc, &dn->data,
+						      &dn->fwnode))
 			result = true;
-	} else if (acpi_enumerate_nondev_subnodes(NULL, desc, &dn->data)) {
+	} else if (acpi_enumerate_nondev_subnodes(NULL, desc, &dn->data,
+						  &dn->fwnode)) {
 		result = true;
 	}
 
@@ -91,7 +96,8 @@ static bool acpi_nondev_subnode_extract(const union acpi_object *desc,
 
 static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
 					const union acpi_object *link,
-					struct list_head *list)
+					struct list_head *list,
+					struct fwnode_handle *parent)
 {
 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 	acpi_status status;
@@ -101,7 +107,8 @@ static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
 	if (ACPI_FAILURE(status))
 		return false;
 
-	if (acpi_nondev_subnode_extract(buf.pointer, handle, link, list))
+	if (acpi_nondev_subnode_extract(buf.pointer, handle, link, list,
+					parent))
 		return true;
 
 	ACPI_FREE(buf.pointer);
@@ -110,7 +117,8 @@ static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
 
 static bool acpi_nondev_subnode_ok(acpi_handle scope,
 				   const union acpi_object *link,
-				   struct list_head *list)
+				   struct list_head *list,
+				   struct fwnode_handle *parent)
 {
 	acpi_handle handle;
 	acpi_status status;
@@ -123,12 +131,13 @@ static bool acpi_nondev_subnode_ok(acpi_handle scope,
 	if (ACPI_FAILURE(status))
 		return false;
 
-	return acpi_nondev_subnode_data_ok(handle, link, list);
+	return acpi_nondev_subnode_data_ok(handle, link, list, parent);
 }
 
 static int acpi_add_nondev_subnodes(acpi_handle scope,
 				    const union acpi_object *links,
-				    struct list_head *list)
+				    struct list_head *list,
+				    struct fwnode_handle *parent)
 {
 	bool ret = false;
 	int i;
@@ -150,15 +159,18 @@ static int acpi_add_nondev_subnodes(acpi_handle scope,
 		/* The second one may be a string, a reference or a package. */
 		switch (link->package.elements[1].type) {
 		case ACPI_TYPE_STRING:
-			result = acpi_nondev_subnode_ok(scope, link, list);
+			result = acpi_nondev_subnode_ok(scope, link, list,
+							 parent);
 			break;
 		case ACPI_TYPE_LOCAL_REFERENCE:
 			handle = link->package.elements[1].reference.handle;
-			result = acpi_nondev_subnode_data_ok(handle, link, list);
+			result = acpi_nondev_subnode_data_ok(handle, link, list,
+							     parent);
 			break;
 		case ACPI_TYPE_PACKAGE:
 			desc = &link->package.elements[1];
-			result = acpi_nondev_subnode_extract(desc, NULL, link, list);
+			result = acpi_nondev_subnode_extract(desc, NULL, link,
+							     list, parent);
 			break;
 		default:
 			result = false;
@@ -172,7 +184,8 @@ static int acpi_add_nondev_subnodes(acpi_handle scope,
 
 static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
 					   const union acpi_object *desc,
-					   struct acpi_device_data *data)
+					   struct acpi_device_data *data,
+					   struct fwnode_handle *parent)
 {
 	int i;
 
@@ -194,7 +207,8 @@ static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
 		if (memcmp(uuid->buffer.pointer, ads_uuid, sizeof(ads_uuid)))
 			continue;
 
-		return acpi_add_nondev_subnodes(scope, links, &data->subnodes);
+		return acpi_add_nondev_subnodes(scope, links, &data->subnodes,
+						parent);
 	}
 
 	return false;
@@ -345,7 +359,8 @@ void acpi_init_properties(struct acpi_device *adev)
 		if (acpi_of)
 			acpi_init_of_compatible(adev);
 	}
-	if (acpi_enumerate_nondev_subnodes(adev->handle, buf.pointer, &adev->data))
+	if (acpi_enumerate_nondev_subnodes(adev->handle, buf.pointer,
+					&adev->data, acpi_fwnode_handle(adev)))
 		adev->data.pointer = buf.pointer;
 
 	if (!adev->data.pointer) {
@@ -920,3 +935,30 @@ struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
 	}
 	return NULL;
 }
+
+/**
+ * acpi_node_get_parent - Return parent fwnode of this fwnode
+ * @fwnode: Firmware node whose parent to get
+ *
+ * Returns parent node of an ACPI device or data firmware node or %NULL if
+ * not available.
+ */
+struct fwnode_handle *acpi_node_get_parent(struct fwnode_handle *fwnode)
+{
+	if (is_acpi_data_node(fwnode)) {
+		/* All data nodes have parent pointer so just return that */
+		return to_acpi_data_node(fwnode)->parent;
+	} else if (is_acpi_device_node(fwnode)) {
+		acpi_handle handle, parent_handle;
+
+		handle = to_acpi_device_node(fwnode)->handle;
+		if (ACPI_SUCCESS(acpi_get_parent(handle, &parent_handle))) {
+			struct acpi_device *adev;
+
+			if (!acpi_bus_get_device(parent_handle, &adev))
+				return acpi_fwnode_handle(adev);
+		}
+	}
+
+	return NULL;
+}
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index ef0ae8a..49cca52 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -386,6 +386,7 @@ struct acpi_data_node {
 	const char *name;
 	acpi_handle handle;
 	struct fwnode_handle fwnode;
+	struct fwnode_handle *parent;
 	struct acpi_device_data data;
 	struct list_head sibling;
 	struct kobject kobj;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 673acda..a6f1b74 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1002,6 +1002,7 @@ int acpi_dev_prop_read(struct acpi_device *adev, const char *propname,
 
 struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
 					    struct fwnode_handle *subnode);
+struct fwnode_handle *acpi_node_get_parent(struct fwnode_handle *fwnode);
 
 struct acpi_probe_entry;
 typedef bool (*acpi_probe_entry_validate_subtbl)(struct acpi_subtable_header *,
@@ -1124,6 +1125,12 @@ static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
 	return NULL;
 }
 
+static inline struct fwnode_handle *
+acpi_node_get_parent(struct fwnode_handle *fwnode)
+{
+	return NULL;
+}
+
 #define ACPI_DECLARE_PROBE_ENTRY(table, name, table_id, subtable, valid, data, fn) \
 	static const void * __acpi_table_##name[]			\
 		__attribute__((unused))					\
-- 
2.7.4

[PATCH v5 02/13] device property: Add fwnode_get_parent()

[Sakari Ailus]

From: Mika Westerberg <mika.westerberg@linux.intel.com>

Now that ACPI has support for returning parent firmware node for both types
of nodes we can expose this to others as well. This adds a new function
fwnode_get_parent() that can be used for DT and ACPI nodes to retrieve the
parent firmware node.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/base/property.c  | 25 +++++++++++++++++++++++++
 include/linux/property.h |  2 ++
 2 files changed, 27 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 82187ac..c83cfa8 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -974,6 +974,31 @@ int device_add_properties(struct device *dev,
 EXPORT_SYMBOL_GPL(device_add_properties);
 
 /**
+ * fwnode_get_parent - Return parent firwmare node
+ * @fwnode: Firmware whose parent is retrieved
+ *
+ * Return parent firmware node of the given node if possible or %NULL if no
+ * parent was available.
+ */
+struct fwnode_handle *fwnode_get_parent(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *parent = NULL;
+
+	if (is_of_node(fwnode)) {
+		struct device_node *node;
+
+		node = of_get_parent(to_of_node(fwnode));
+		if (node)
+			parent = &node->fwnode;
+	} else if (is_acpi_node(fwnode)) {
+		parent = acpi_node_get_parent(fwnode);
+	}
+
+	return parent;
+}
+EXPORT_SYMBOL_GPL(fwnode_get_parent);
+
+/**
  * device_get_next_child_node - Return the next child node handle for a device
  * @dev: Device to find the next child node for.
  * @child: Handle to one of the device's child nodes or a null handle.
diff --git a/include/linux/property.h b/include/linux/property.h
index 64e3a9c..ab0a816 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -70,6 +70,8 @@ int fwnode_property_read_string(struct fwnode_handle *fwnode,
 int fwnode_property_match_string(struct fwnode_handle *fwnode,
 				 const char *propname, const char *string);
 
+struct fwnode_handle *fwnode_get_parent(struct fwnode_handle *fwnode);
+
 struct fwnode_handle *device_get_next_child_node(struct device *dev,
 						 struct fwnode_handle *child);
 
-- 
2.7.4

[PATCH v5 03/13] ACPI / property: Add fwnode_get_next_child_node()

[Sakari Ailus]

From: Mika Westerberg <mika.westerberg@linux.intel.com>

The ACPI _DSD hierarchical data extension [1] makes it possible to have
hierarchies deeper than one level in similar way than DT allows. These
"subsubnodes" have not been accessible because device property
implementation only provides device_get_next_child_node() that is limited
to direct descendants of a device.

We need this ability in order support things like remote endpoints
currently supported in DT with of_graph_* APIs.

Modify acpi_get_next_subnode() to accept fwnode handle instead and update
callers accordingly. Also add a new function fwnode_get_next_child_node()
that works directly with fwnodes and modify device_get_next_child_node() to
call it directly. While there add a macro fwnode_for_each_child_node()
analogous to the current device_for_each_child_node() but it works with
fwnodes instead of devices.

[1] http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.pdf

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/acpi/property.c  | 27 +++++++++++++++++----------
 drivers/base/property.c  | 38 ++++++++++++++++++++++++++++++--------
 include/linux/acpi.h     |  8 ++++----
 include/linux/property.h |  6 ++++++
 4 files changed, 57 insertions(+), 22 deletions(-)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 587c9d0..8730ce7 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -880,21 +880,22 @@ int acpi_node_prop_read(struct fwnode_handle *fwnode,  const char *propname,
 }
 
 /**
- * acpi_get_next_subnode - Return the next child node handle for a device.
- * @dev: Device to find the next child node for.
+ * acpi_get_next_subnode - Return the next child node handle for a fwnode
+ * @fwnode: Firmware node to find the next child node for.
  * @child: Handle to one of the device's child nodes or a null handle.
  */
-struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
+struct fwnode_handle *acpi_get_next_subnode(struct fwnode_handle *fwnode,
 					    struct fwnode_handle *child)
 {
-	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct acpi_device *adev = to_acpi_device_node(fwnode);
 	struct list_head *head, *next;
 
-	if (!adev)
-		return NULL;
-
 	if (!child || child->type == FWNODE_ACPI) {
-		head = &adev->children;
+		if (adev)
+			head = &adev->children;
+		else
+			goto nondev;
+
 		if (list_empty(head))
 			goto nondev;
 
@@ -903,7 +904,6 @@ struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
 			next = adev->node.next;
 			if (next == head) {
 				child = NULL;
-				adev = ACPI_COMPANION(dev);
 				goto nondev;
 			}
 			adev = list_entry(next, struct acpi_device, node);
@@ -915,9 +915,16 @@ struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
 
  nondev:
 	if (!child || child->type == FWNODE_ACPI_DATA) {
+		struct acpi_data_node *data = to_acpi_data_node(fwnode);
 		struct acpi_data_node *dn;
 
-		head = &adev->data.subnodes;
+		if (adev)
+			head = &adev->data.subnodes;
+		else if (data)
+			head = &data->data.subnodes;
+		else
+			return NULL;
+
 		if (list_empty(head))
 			return NULL;
 
diff --git a/drivers/base/property.c b/drivers/base/property.c
index c83cfa8..26286d4 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -999,24 +999,46 @@ struct fwnode_handle *fwnode_get_parent(struct fwnode_handle *fwnode)
 EXPORT_SYMBOL_GPL(fwnode_get_parent);
 
 /**
- * device_get_next_child_node - Return the next child node handle for a device
- * @dev: Device to find the next child node for.
- * @child: Handle to one of the device's child nodes or a null handle.
+ * fwnode_get_next_child_node - Return the next child node handle for a node
+ * @fwnode: Firmware node to find the next child node for.
+ * @child: Handle to one of the node's child nodes or a %NULL handle.
  */
-struct fwnode_handle *device_get_next_child_node(struct device *dev,
+struct fwnode_handle *fwnode_get_next_child_node(struct fwnode_handle *fwnode,
 						 struct fwnode_handle *child)
 {
-	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
+	if (is_of_node(fwnode)) {
 		struct device_node *node;
 
-		node = of_get_next_available_child(dev->of_node, to_of_node(child));
+		node = of_get_next_available_child(to_of_node(fwnode),
+						   to_of_node(child));
 		if (node)
 			return &node->fwnode;
-	} else if (IS_ENABLED(CONFIG_ACPI)) {
-		return acpi_get_next_subnode(dev, child);
+	} else if (is_acpi_node(fwnode)) {
+		return acpi_get_next_subnode(fwnode, child);
 	}
+
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(fwnode_get_next_child_node);
+
+/**
+ * device_get_next_child_node - Return the next child node handle for a device
+ * @dev: Device to find the next child node for.
+ * @child: Handle to one of the device's child nodes or a null handle.
+ */
+struct fwnode_handle *device_get_next_child_node(struct device *dev,
+						 struct fwnode_handle *child)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct fwnode_handle *fwnode = NULL;
+
+	if (dev->of_node)
+		fwnode = &dev->of_node->fwnode;
+	else if (adev)
+		fwnode = acpi_fwnode_handle(adev);
+
+	return fwnode_get_next_child_node(fwnode, child);
+}
 EXPORT_SYMBOL_GPL(device_get_next_child_node);
 
 /**
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index a6f1b74..8096b3a 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1000,8 +1000,8 @@ int acpi_node_prop_read(struct fwnode_handle *fwnode, const char *propname,
 int acpi_dev_prop_read(struct acpi_device *adev, const char *propname,
 		       enum dev_prop_type proptype, void *val, size_t nval);
 
-struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
-					    struct fwnode_handle *subnode);
+struct fwnode_handle *acpi_get_next_subnode(struct fwnode_handle *fwnode,
+					    struct fwnode_handle *child);
 struct fwnode_handle *acpi_node_get_parent(struct fwnode_handle *fwnode);
 
 struct acpi_probe_entry;
@@ -1119,8 +1119,8 @@ static inline int acpi_dev_prop_read(struct acpi_device *adev,
 	return -ENXIO;
 }
 
-static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
-						struct fwnode_handle *subnode)
+static inline struct fwnode_handle *
+acpi_get_next_subnode(struct fwnode_handle *fwnode, struct fwnode_handle *child)
 {
 	return NULL;
 }
diff --git a/include/linux/property.h b/include/linux/property.h
index ab0a816..f4786a86 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -71,6 +71,12 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
 				 const char *propname, const char *string);
 
 struct fwnode_handle *fwnode_get_parent(struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_get_next_child_node(struct fwnode_handle *fwnode,
+						 struct fwnode_handle *child);
+
+#define fwnode_for_each_child_node(fwnode, child)			\
+	for (child = fwnode_get_next_child_node(fwnode, NULL); child;	\
+	     child = fwnode_get_next_child_node(fwnode, child))
 
 struct fwnode_handle *device_get_next_child_node(struct device *dev,
 						 struct fwnode_handle *child);
-- 
2.7.4

[PATCH v5 04/13] device property: Add fwnode_get_named_child_node()

[Sakari Ailus]

From: Mika Westerberg <mika.westerberg@linux.intel.com>

Since now we have means to enumerate all children of any fwnode even in
ACPI we can implement fwnode_get_named_child_node(). This is similar than
device_get_named_child_node() with the exception that it can be called to
any fwnode handle. Make device_get_named_child_node() call directly this
new function.

This is useful in cases where we need to be able to find child nodes which
are not direct descendants of the parent device.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/base/property.c  | 22 +++++++++++++++++-----
 include/linux/property.h |  2 ++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 26286d4..c8f3ae8 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1042,20 +1042,20 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev,
 EXPORT_SYMBOL_GPL(device_get_next_child_node);
 
 /**
- * device_get_named_child_node - Return first matching named child node handle
- * @dev: Device to find the named child node for.
+ * fwnode_get_named_child_node - Return first matching named child node handle
+ * @fwnode: Firmware node to find the named child node for.
  * @childname: String to match child node name against.
  */
-struct fwnode_handle *device_get_named_child_node(struct device *dev,
+struct fwnode_handle *fwnode_get_named_child_node(struct fwnode_handle *fwnode,
 						  const char *childname)
 {
 	struct fwnode_handle *child;
 
 	/*
-	 * Find first matching named child node of this device.
+	 * Find first matching named child node of this fwnode.
 	 * For ACPI this will be a data only sub-node.
 	 */
-	device_for_each_child_node(dev, child) {
+	fwnode_for_each_child_node(fwnode, child) {
 		if (is_of_node(child)) {
 			if (!of_node_cmp(to_of_node(child)->name, childname))
 				return child;
@@ -1067,6 +1067,18 @@ struct fwnode_handle *device_get_named_child_node(struct device *dev,
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(fwnode_get_named_child_node);
+
+/**
+ * device_get_named_child_node - Return first matching named child node handle
+ * @dev: Device to find the named child node for.
+ * @childname: String to match child node name against.
+ */
+struct fwnode_handle *device_get_named_child_node(struct device *dev,
+						  const char *childname)
+{
+	return fwnode_get_named_child_node(dev_fwnode(dev), childname);
+}
 EXPORT_SYMBOL_GPL(device_get_named_child_node);
 
 /**
diff --git a/include/linux/property.h b/include/linux/property.h
index f4786a86..514b195 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -85,6 +85,8 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev,
 	for (child = device_get_next_child_node(dev, NULL); child;	\
 	     child = device_get_next_child_node(dev, child))
 
+struct fwnode_handle *fwnode_get_named_child_node(struct fwnode_handle *fwnode,
+						  const char *childname);
 struct fwnode_handle *device_get_named_child_node(struct device *dev,
 						  const char *childname);
 
-- 
2.7.4

[PATCH v5 06/13] device property: Add support for remote endpoints

[Sakari Ailus]

From: Mika Westerberg <mika.westerberg@linux.intel.com>

This follows DT implementation of of_graph_* APIs but we call them
fwnode_graph_* instead. For DT nodes the existing of_graph_* implementation
will be used. For ACPI we use the new ACPI graph implementation instead.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/base/property.c  | 123 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/property.h |   9 ++++
 2 files changed, 132 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index c8f3ae8..851b33f 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -15,6 +15,7 @@
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_graph.h>
 #include <linux/property.h>
 #include <linux/etherdevice.h>
 #include <linux/phy.h>
@@ -1218,3 +1219,125 @@ void *device_get_mac_address(struct device *dev, char *addr, int alen)
 	return device_get_mac_addr(dev, "address", addr, alen);
 }
 EXPORT_SYMBOL(device_get_mac_address);
+
+/**
+ * device_graph_get_next_endpoint - Get next endpoint firmware node
+ * @fwnode: Pointer to the parent firmware node
+ * @prev: Previous endpoint node or %NULL to get the first
+ *
+ * Returns an endpoint firmware node pointer or %NULL if no more endpoints
+ * are available.
+ */
+struct fwnode_handle *
+fwnode_graph_get_next_endpoint(struct fwnode_handle *fwnode,
+			       struct fwnode_handle *prev)
+{
+	struct fwnode_handle *endpoint = NULL;
+
+	if (is_of_node(fwnode)) {
+		struct device_node *node;
+
+		node = of_graph_get_next_endpoint(to_of_node(fwnode),
+						  to_of_node(prev));
+
+		if (node)
+			endpoint = &node->fwnode;
+	} else if (is_acpi_node(fwnode)) {
+		endpoint = acpi_graph_get_next_endpoint(fwnode, prev);
+		if (IS_ERR(endpoint))
+			endpoint = NULL;
+	}
+
+	return endpoint;
+
+}
+EXPORT_SYMBOL_GPL(fwnode_graph_get_next_endpoint);
+
+/**
+ * fwnode_graph_get_remote_port_parent - Return fwnode of a remote device
+ * @fwnode: Endpoint firmware node pointing to the remote endpoint
+ *
+ * Extracts firmware node of a remote device the @fwnode points to.
+ */
+struct fwnode_handle *
+fwnode_graph_get_remote_port_parent(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *parent = NULL;
+
+	if (is_of_node(fwnode)) {
+		struct device_node *node;
+
+		node = of_graph_get_remote_port_parent(to_of_node(fwnode));
+		if (node)
+			parent = &node->fwnode;
+	} else if (is_acpi_node(fwnode)) {
+		int ret;
+
+		ret = acpi_graph_get_remote_endpoint(fwnode, &parent, NULL,
+						     NULL);
+		if (ret)
+			return NULL;
+	}
+
+	return parent;
+}
+EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_port_parent);
+
+/**
+ * fwnode_graph_get_remote_port - Return fwnode of a remote port
+ * @fwnode: Endpoint firmware node pointing to the remote endpoint
+ *
+ * Extracts firmware node of a remote port the @fwnode points to.
+ */
+struct fwnode_handle *fwnode_graph_get_remote_port(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *port = NULL;
+
+	if (is_of_node(fwnode)) {
+		struct device_node *node;
+
+		node = of_graph_get_remote_port(to_of_node(fwnode));
+		if (node)
+			port = &node->fwnode;
+	} else if (is_acpi_node(fwnode)) {
+		int ret;
+
+		ret = acpi_graph_get_remote_endpoint(fwnode, NULL, &port, NULL);
+		if (ret)
+			return NULL;
+	}
+
+	return port;
+}
+EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_port);
+
+/**
+ * fwnode_graph_get_remote_endpoint - Return fwnode of a remote endpoint
+ * @fwnode: Endpoint firmware node pointing to the remote endpoint
+ *
+ * Extracts firmware node of a remote endpoint the @fwnode points to.
+ */
+struct fwnode_handle *
+fwnode_graph_get_remote_endpoint(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *endpoint = NULL;
+
+	if (is_of_node(fwnode)) {
+		struct device_node *node;
+
+		node = of_parse_phandle(to_of_node(fwnode), "remote-endpoint",
+					0);
+		if (node)
+			endpoint = &node->fwnode;
+	} else if (is_acpi_node(fwnode)) {
+		int ret;
+
+		ret = acpi_graph_get_remote_endpoint(fwnode, NULL, NULL,
+						     &endpoint);
+		if (ret)
+			return NULL;
+	}
+
+	return endpoint;
+}
+EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_endpoint);
diff --git a/include/linux/property.h b/include/linux/property.h
index 514b195..8d7809c 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -268,4 +268,13 @@ int device_get_phy_mode(struct device *dev);
 
 void *device_get_mac_address(struct device *dev, char *addr, int alen);
 
+struct fwnode_handle *fwnode_graph_get_next_endpoint(
+	struct fwnode_handle *fwnode, struct fwnode_handle *prev);
+struct fwnode_handle *fwnode_graph_get_remote_port_parent(
+	struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_graph_get_remote_port(
+	struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_graph_get_remote_endpoint(
+	struct fwnode_handle *fwnode);
+
 #endif /* _LINUX_PROPERTY_H_ */
-- 
2.7.4

[PATCH v5 07/13] device property: Add fwnode_handle_get()

[Sakari Ailus]

fwnode_handle_get() is used to obtain a reference to a fwnode_handle
container. In this case this is OF specific struct device_node.

This complements fwnode_handle_put() which is already implemented.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/base/property.c  | 11 +++++++++++
 include/linux/property.h |  1 +
 2 files changed, 12 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 851b33f..6a8d8ae 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1083,6 +1083,17 @@ struct fwnode_handle *device_get_named_child_node(struct device *dev,
 EXPORT_SYMBOL_GPL(device_get_named_child_node);
 
 /**
+ * fwnode_handle_get - Obtain a reference to a device node
+ * @fwnode: Pointer to the device node to obtain the reference to.
+ */
+void fwnode_handle_get(struct fwnode_handle *fwnode)
+{
+	if (is_of_node(fwnode))
+		of_node_get(to_of_node(fwnode));
+}
+EXPORT_SYMBOL_GPL(fwnode_handle_get);
+
+/**
  * fwnode_handle_put - Drop reference to a device node
  * @fwnode: Pointer to the device node to drop the reference to.
  *
diff --git a/include/linux/property.h b/include/linux/property.h
index 8d7809c..0ae7d20 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -90,6 +90,7 @@ struct fwnode_handle *fwnode_get_named_child_node(struct fwnode_handle *fwnode,
 struct fwnode_handle *device_get_named_child_node(struct device *dev,
 						  const char *childname);
 
+void fwnode_handle_get(struct fwnode_handle *fwnode);
 void fwnode_handle_put(struct fwnode_handle *fwnode);
 
 unsigned int device_get_child_node_count(struct device *dev);
-- 
2.7.4

[PATCH v5 08/13] of: Add of_fwnode_handle() to convert device nodes to fwnode_handle

[Sakari Ailus]

of_fwnode_handle() returns a struct fwnode_handle of the struct
device_node. This may be used on the fwnode property API.

Use a macro instead of a function in order to support const and non-const
arguments.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 include/linux/of.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/of.h b/include/linux/of.h
index 21e6323..e5d4225f 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -159,6 +159,8 @@ static inline struct device_node *to_of_node(struct fwnode_handle *fwnode)
 		container_of(fwnode, struct device_node, fwnode) : NULL;
 }
 
+#define of_fwnode_handle(node) (&(node)->fwnode)
+
 static inline bool of_have_populated_dt(void)
 {
 	return of_root != NULL;
@@ -602,6 +604,8 @@ static inline struct device_node *of_find_node_with_property(
 	return NULL;
 }
 
+#define of_fwnode_handle(node) NULL
+
 static inline bool of_have_populated_dt(void)
 {
 	return false;
-- 
2.7.4

[PATCH v5 10/13] device property: Add support for fwnode endpoints

[Sakari Ailus]

Similar to OF endpoints, endpoint type nodes can be also supported on
ACPI. In order to make it possible for drivers to ignore the matter,
add a type for fwnode_endpoint and a function to parse them.

On ACPI, find the child node index instead of relying on the "endpoint"
property.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/base/property.c  | 38 ++++++++++++++++++++++++++++++++++++++
 include/linux/fwnode.h   | 12 ++++++++++++
 include/linux/property.h |  3 +++
 3 files changed, 53 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 4c7956e..09f348d 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1353,3 +1353,41 @@ fwnode_graph_get_remote_endpoint(struct fwnode_handle *fwnode)
 	return endpoint;
 }
 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_endpoint);
+
+/**
+ * fwnode_graph_parse_endpoint - parse common endpoint node properties
+ * @fwnode: pointer to endpoint fwnode_handle
+ * @endpoint: pointer to the fwnode endpoint data structure
+ *
+ * Parse @fwnode representing a graph endpoint node and store the
+ * information in @endpoint. The caller must hold a reference to
+ * @fwnode.
+ */
+int fwnode_graph_parse_endpoint(struct fwnode_handle *fwnode,
+				struct fwnode_endpoint *endpoint)
+{
+	struct fwnode_handle *port_fwnode = fwnode_get_parent(fwnode);
+
+	memset(endpoint, 0, sizeof(*endpoint));
+
+	endpoint->local_fwnode = fwnode;
+
+	if (is_acpi_node(port_fwnode)) {
+		struct fwnode_handle *iter;
+
+		fwnode_property_read_u32(port_fwnode, "port", &endpoint->port);
+
+		for (iter = fwnode_get_next_child_node(port_fwnode, NULL);
+		     iter != fwnode;
+		     iter = fwnode_get_next_child_node(port_fwnode, iter))
+			endpoint->id++;
+	} else {
+		fwnode_property_read_u32(port_fwnode, "reg", &endpoint->port);
+		fwnode_property_read_u32(fwnode, "reg", &endpoint->id);
+	}
+
+	fwnode_handle_put(port_fwnode);
+
+	return 0;
+}
+EXPORT_SYMBOL(fwnode_graph_parse_endpoint);
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 8bd28ce..3dff239 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -27,4 +27,16 @@ struct fwnode_handle {
 	struct fwnode_handle *secondary;
 };
 
+/**
+ * struct fwnode_endpoint - Fwnode graph endpoint
+ * @port: Port number
+ * @id: Endpoint id
+ * @local_fwnode: reference to the related fwnode
+ */
+struct fwnode_endpoint {
+	unsigned int port;
+	unsigned int id;
+	const struct fwnode_handle *local_fwnode;
+};
+
 #endif
diff --git a/include/linux/property.h b/include/linux/property.h
index 6e20a12..3a4e435 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -280,4 +280,7 @@ struct fwnode_handle *fwnode_graph_get_remote_port(
 struct fwnode_handle *fwnode_graph_get_remote_endpoint(
 	struct fwnode_handle *fwnode);
 
+int fwnode_graph_parse_endpoint(struct fwnode_handle *fwnode,
+				struct fwnode_endpoint *endpoint);
+
 #endif /* _LINUX_PROPERTY_H_ */
-- 
2.7.4

[PATCH v5.1 10/13] device property: Add support for fwnode endpoints

[Sakari Ailus]

Similar to OF endpoints, endpoint type nodes can be also supported on
ACPI. In order to make it possible for drivers to ignore the matter,
add a type for fwnode_endpoint and a function to parse them.

On ACPI, find the child node index instead of relying on the "endpoint"
property.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
since v5:

- Read the "endpoint" property on ACPI to read the endpoint number.

 drivers/base/property.c  | 32 ++++++++++++++++++++++++++++++++
 include/linux/fwnode.h   | 12 ++++++++++++
 include/linux/property.h |  3 +++
 3 files changed, 47 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 4c7956e..a4fe66c 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1353,3 +1353,35 @@ fwnode_graph_get_remote_endpoint(struct fwnode_handle *fwnode)
 	return endpoint;
 }
 EXPORT_SYMBOL_GPL(fwnode_graph_get_remote_endpoint);
+
+/**
+ * fwnode_graph_parse_endpoint - parse common endpoint node properties
+ * @fwnode: pointer to endpoint fwnode_handle
+ * @endpoint: pointer to the fwnode endpoint data structure
+ *
+ * Parse @fwnode representing a graph endpoint node and store the
+ * information in @endpoint. The caller must hold a reference to
+ * @fwnode.
+ */
+int fwnode_graph_parse_endpoint(struct fwnode_handle *fwnode,
+				struct fwnode_endpoint *endpoint)
+{
+	struct fwnode_handle *port_fwnode = fwnode_get_parent(fwnode);
+
+	memset(endpoint, 0, sizeof(*endpoint));
+
+	endpoint->local_fwnode = fwnode;
+
+	if (is_acpi_node(port_fwnode)) {
+		fwnode_property_read_u32(port_fwnode, "port", &endpoint->port);
+		fwnode_property_read_u32(fwnode, "endpoint", &endpoint->id);
+	} else {
+		fwnode_property_read_u32(port_fwnode, "reg", &endpoint->port);
+		fwnode_property_read_u32(fwnode, "reg", &endpoint->id);
+	}
+
+	fwnode_handle_put(port_fwnode);
+
+	return 0;
+}
+EXPORT_SYMBOL(fwnode_graph_parse_endpoint);
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 8bd28ce..3dff239 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -27,4 +27,16 @@ struct fwnode_handle {
 	struct fwnode_handle *secondary;
 };
 
+/**
+ * struct fwnode_endpoint - Fwnode graph endpoint
+ * @port: Port number
+ * @id: Endpoint id
+ * @local_fwnode: reference to the related fwnode
+ */
+struct fwnode_endpoint {
+	unsigned int port;
+	unsigned int id;
+	const struct fwnode_handle *local_fwnode;
+};
+
 #endif
diff --git a/include/linux/property.h b/include/linux/property.h
index 6e20a12..3a4e435 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -280,4 +280,7 @@ struct fwnode_handle *fwnode_graph_get_remote_port(
 struct fwnode_handle *fwnode_graph_get_remote_endpoint(
 	struct fwnode_handle *fwnode);
 
+int fwnode_graph_parse_endpoint(struct fwnode_handle *fwnode,
+				struct fwnode_endpoint *endpoint);
+
 #endif /* _LINUX_PROPERTY_H_ */
-- 
2.7.4

[PATCH v5 05/13] ACPI / property: Add support for remote endpoints

[Sakari Ailus]

From: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

DT has had concept of remote endpoints for some time already. It makes
possible to reference another firmware node through a property called
remote-endpoint. This is already used by some subsystems like v4l2 for
parsing hardware properties related to camera.

This patch adds ACPI support for remote endpoints utilizing _DSD
hierarchical data extensions.

Signed-off-by: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/acpi/property.c | 138 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/acpi.h    |  23 ++++++++
 2 files changed, 161 insertions(+)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 8730ce7..9eb7c13 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -969,3 +969,141 @@ struct fwnode_handle *acpi_node_get_parent(struct fwnode_handle *fwnode)
 
 	return NULL;
 }
+
+/**
+ * acpi_graph_get_next_endpoint - Get next endpoint ACPI firmware node
+ * @fwnode: Pointer to the parent firmware node
+ * @prev: Previous endpoint node or %NULL to get the first
+ *
+ * Looks up next endpoint ACPI firmware node below a given @fwnode. Returns
+ * %NULL if there is no next endpoint, ERR_PTR() in case of error. In case
+ * of success the next endpoint is returned.
+ */
+struct fwnode_handle *acpi_graph_get_next_endpoint(struct fwnode_handle *fwnode,
+						   struct fwnode_handle *prev)
+{
+	struct fwnode_handle *port = NULL;
+	struct fwnode_handle *endpoint;
+
+	if (!prev) {
+		do {
+			port = fwnode_get_next_child_node(fwnode, port);
+			/* Ports must have port property */
+			if (fwnode_property_present(port, "port"))
+				break;
+		} while (port);
+	} else {
+		port = fwnode_get_parent(prev);
+	}
+
+	if (!port)
+		return NULL;
+
+	endpoint = fwnode_get_next_child_node(port, prev);
+	while (!endpoint) {
+		port = fwnode_get_next_child_node(fwnode, port);
+		if (!port)
+			break;
+		if (fwnode_property_present(port, "port"))
+			endpoint = fwnode_get_next_child_node(port, NULL);
+	}
+
+	if (endpoint) {
+		/* Endpoints must have "endpoint" property */
+		if (!fwnode_property_present(endpoint, "endpoint"))
+			return ERR_PTR(-EPROTO);
+	}
+
+	return endpoint;
+}
+
+/**
+ * acpi_graph_get_child_prop_value - Return a child with a given property value
+ * @fwnode: device fwnode
+ * @prop_name: The name of the property to look for
+ * @val: the desired property value
+ *
+ * Return the port node corresponding to a given port number. Returns
+ * the child node on success, NULL otherwise.
+ */
+static struct fwnode_handle *acpi_graph_get_child_prop_value(
+	struct fwnode_handle *fwnode, const char *prop_name, unsigned int val)
+{
+	struct fwnode_handle *child;
+
+	fwnode_for_each_child_node(fwnode, child) {
+		u32 nr;
+
+		if (!fwnode_property_read_u32(fwnode, prop_name, &nr))
+			continue;
+
+		if (val == nr)
+			return child;
+	}
+
+	return NULL;
+}
+
+
+/**
+ * acpi_graph_get_remote_enpoint - Parses and returns remote end of an endpoint
+ * @fwnode: Endpoint firmware node pointing to a remote device
+ * @parent: Firmware node of remote port parent is filled here if not %NULL
+ * @port: Firmware node of remote port is filled here if not %NULL
+ * @endpoint: Firmware node of remote endpoint is filled here if not %NULL
+ *
+ * Function parses remote end of ACPI firmware remote endpoint and fills in
+ * fields requested by the caller. Returns %0 in case of success and
+ * negative errno otherwise.
+ */
+int acpi_graph_get_remote_endpoint(struct fwnode_handle *fwnode,
+				   struct fwnode_handle **parent,
+				   struct fwnode_handle **port,
+				   struct fwnode_handle **endpoint)
+{
+	unsigned int port_nr, endpoint_nr;
+	struct acpi_reference_args args;
+	int ret;
+
+	memset(&args, 0, sizeof(args));
+	ret = acpi_node_get_property_reference(fwnode, "remote-endpoint", 0,
+					       &args);
+	if (ret)
+		return ret;
+
+	/*
+	 * Always require two arguments with the reference: port and
+	 * endpoint indices.
+	 */
+	if (args.nargs != 2)
+		return -EPROTO;
+
+	fwnode = acpi_fwnode_handle(args.adev);
+	port_nr = args.args[0];
+	endpoint_nr = args.args[1];
+
+	if (parent)
+		*parent = fwnode;
+
+	if (!port && !endpoint)
+		return 0;
+
+	fwnode = acpi_graph_get_child_prop_value(fwnode, "port", port_nr);
+	if (!fwnode)
+		return -EPROTO;
+
+	if (port)
+		*port = fwnode;
+
+	if (!endpoint)
+		return 0;
+
+	fwnode = acpi_graph_get_child_prop_value(fwnode, "endpoint",
+						 endpoint_nr);
+	if (!fwnode)
+		return -EPROTO;
+
+	*endpoint = fwnode;
+
+	return 0;
+}
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 8096b3a..9d920c0 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1004,6 +1004,13 @@ struct fwnode_handle *acpi_get_next_subnode(struct fwnode_handle *fwnode,
 					    struct fwnode_handle *child);
 struct fwnode_handle *acpi_node_get_parent(struct fwnode_handle *fwnode);
 
+struct fwnode_handle *acpi_graph_get_next_endpoint(struct fwnode_handle *fwnode,
+						   struct fwnode_handle *prev);
+int acpi_graph_get_remote_endpoint(struct fwnode_handle *fwnode,
+				   struct fwnode_handle **remote,
+				   struct fwnode_handle **port,
+				   struct fwnode_handle **endpoint);
+
 struct acpi_probe_entry;
 typedef bool (*acpi_probe_entry_validate_subtbl)(struct acpi_subtable_header *,
 						 struct acpi_probe_entry *);
@@ -1131,6 +1138,22 @@ acpi_node_get_parent(struct fwnode_handle *fwnode)
 	return NULL;
 }
 
+static inline struct fwnode_handle *
+acpi_graph_get_next_endpoint(struct fwnode_handle *fwnode,
+			     struct fwnode_handle *prev)
+{
+	return ERR_PTR(-ENXIO);
+}
+
+static inline int
+acpi_graph_get_remote_endpoint(struct fwnode_handle *fwnode,
+			       struct fwnode_handle **remote,
+			       struct fwnode_handle **port,
+			       struct fwnode_handle **endpoint)
+{
+	return -ENXIO;
+}
+
 #define ACPI_DECLARE_PROBE_ENTRY(table, name, table_id, subtable, valid, data, fn) \
 	static const void * __acpi_table_##name[]			\
 		__attribute__((unused))					\
-- 
2.7.4

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[PATCH v5 09/13] device property: Make dev_fwnode() public

[Sakari Ailus]

The function to obtain a fwnode related to a struct device is useful for
drivers that use the fwnode property API: it allows not being aware of the
underlying firmware implementation.

Signed-off-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/base/property.c  | 3 ++-
 include/linux/property.h | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 6a8d8ae..4c7956e 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -183,11 +183,12 @@ static int pset_prop_read_string(struct property_set *pset,
 	return 0;
 }
 
-static inline struct fwnode_handle *dev_fwnode(struct device *dev)
+struct fwnode_handle *dev_fwnode(struct device *dev)
 {
 	return IS_ENABLED(CONFIG_OF) && dev->of_node ?
 		&dev->of_node->fwnode : dev->fwnode;
 }
+EXPORT_SYMBOL_GPL(dev_fwnode);
 
 /**
  * device_property_present - check if a property of a device is present
diff --git a/include/linux/property.h b/include/linux/property.h
index 0ae7d20..6e20a12 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -33,6 +33,8 @@ enum dev_dma_attr {
 	DEV_DMA_COHERENT,
 };
 
+struct fwnode_handle *dev_fwnode(struct device *dev);
+
 bool device_property_present(struct device *dev, const char *propname);
 int device_property_read_u8_array(struct device *dev, const char *propname,
 				  u8 *val, size_t nval);
-- 
2.7.4

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[PATCH v5 11/13] of: Add nop implementation of of_get_next_parent()

[Sakari Ailus]

of_get_next_parent() was only defined if CONFIG_OF was set. This required
nop implementation of of_get_next_parent() in order to avoid that.

Signed-off-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 include/linux/of.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/of.h b/include/linux/of.h
index e5d4225f..cc212a0 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -586,6 +586,12 @@ static inline struct device_node *of_get_parent(const struct device_node *node)
 	return NULL;
 }
 
+static inline struct device_node *of_get_next_parent(
+	const struct device_node *node)
+{
+	return NULL;
+}
+
 static inline struct device_node *of_get_next_child(
 	const struct device_node *node, struct device_node *prev)
 {
-- 
2.7.4

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[PATCH v5.1 11/13] of: Add nop implementation of of_get_next_parent()

[Sakari Ailus]

of_get_next_parent() was only defined if CONFIG_OF was set. Using the
function thus requires #ifdef CONFIG_OF ... #endif in all cases. Avoid
having to use pre-processor macros around the function by providing a nop
implementation of of_get_next_parent().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
since v5:

- Improved commit message.

 include/linux/of.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/of.h b/include/linux/of.h
index e5d4225f..cc212a0 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -586,6 +586,12 @@ static inline struct device_node *of_get_parent(const struct device_node *node)
 	return NULL;
 }
 
+static inline struct device_node *of_get_next_parent(
+	const struct device_node *node)
+{
+	return NULL;
+}
+
 static inline struct device_node *of_get_next_child(
 	const struct device_node *node, struct device_node *prev)
 {
-- 
2.7.4

Re: [PATCH v5.1 11/13] of: Add nop implementation of of_get_next_parent()

[Sakari Ailus]

On Fri, Mar 17, 2017 at 02:08:58PM +0200, Sakari Ailus wrote:
> of_get_next_parent() was only defined if CONFIG_OF was set. Using the
> function thus requires #ifdef CONFIG_OF ... #endif in all cases. Avoid
> having to use pre-processor macros around the function by providing a nop
> implementation of of_get_next_parent().
> 
> Signed-off-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

As a result of the changes in v5.1 in the patch 12/13 ("device property: Add
fwnode_get_next_parent()") of this set, this patch is no longer needed. If
there are no objections, I'll drop it from the set.

> ---
> since v5:
> 
> - Improved commit message.
> 
>  include/linux/of.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/include/linux/of.h b/include/linux/of.h
> index e5d4225f..cc212a0 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -586,6 +586,12 @@ static inline struct device_node *of_get_parent(const struct device_node *node)
>  	return NULL;
>  }
>  
> +static inline struct device_node *of_get_next_parent(
> +	const struct device_node *node)
> +{
> +	return NULL;
> +}
> +
>  static inline struct device_node *of_get_next_child(
>  	const struct device_node *node, struct device_node *prev)
>  {

-- 
Sakari Ailus
e-mail: sakari.ailus-X3B1VOXEql0@public.gmane.org	XMPP: sailus-PCDdDYkjdNMDXYZnReoRVg@public.gmane.org
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Re: [PATCH v5 00/13] ACPI graph support

[Mika Westerberg]

On Thu, Mar 16, 2017 at 02:31:08PM +0200, Sakari Ailus wrote:
> Hello everyone,
> 
> This is the fifth version of the ACPI graph support patchset.
> 
> The previous RFC version of the set is available here:
> 
> <URL:http://www.spinics.net/lists/linux-acpi/msg69547.html> 
> 
> There are also v1, v2, v3 and v4 which can be found here:
> 
> <URL:http://www.spinics.net/lists/linux-acpi/msg71661.html>
> <URL:http://www.spinics.net/lists/linux-acpi/msg71809.html>
> <URL:http://www.spinics.net/lists/linux-acpi/msg72171.html>
> <URL:http://www.spinics.net/lists/linux-acpi/msg72346.html>
> 
> This set contains patches written by Mika Westerberg and by myself. The 
> patchset brings support for graphs to ACPI. The functionality achieved by 
> these patches is very similar to what the Device tree provides: the port
> and the endpoint concept are being employed. The patches make use of the
> _DSD property and data extensions to achieve this. The fwnode interface is
> extended by graph functionality; this way graph information originating 
> from both OF and ACPI may be accessed using the same interface, without 
> being aware of the underlying firmware interface. 
> 
> The last patch of the set contains ASL documentation including an example.

It would be helpful if you include similar diffstat here as running 'git
format-patch --cover-letter ...' generates.

Anyway for patches 7-13,

Reviewed-by: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
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Re: [PATCH v5 00/13] ACPI graph support

[Sakari Ailus]

Hi Mika,

Mika Westerberg wrote:
> On Thu, Mar 16, 2017 at 02:31:08PM +0200, Sakari Ailus wrote:
>> Hello everyone,
>>
>> This is the fifth version of the ACPI graph support patchset.
>>
>> The previous RFC version of the set is available here:
>>
>> <URL:http://www.spinics.net/lists/linux-acpi/msg69547.html>
>>
>> There are also v1, v2, v3 and v4 which can be found here:
>>
>> <URL:http://www.spinics.net/lists/linux-acpi/msg71661.html>
>> <URL:http://www.spinics.net/lists/linux-acpi/msg71809.html>
>> <URL:http://www.spinics.net/lists/linux-acpi/msg72171.html>
>> <URL:http://www.spinics.net/lists/linux-acpi/msg72346.html>
>>
>> This set contains patches written by Mika Westerberg and by myself. The
>> patchset brings support for graphs to ACPI. The functionality achieved by
>> these patches is very similar to what the Device tree provides: the port
>> and the endpoint concept are being employed. The patches make use of the
>> _DSD property and data extensions to achieve this. The fwnode interface is
>> extended by graph functionality; this way graph information originating
>> from both OF and ACPI may be accessed using the same interface, without
>> being aware of the underlying firmware interface.
>>
>> The last patch of the set contains ASL documentation including an example.
>
> It would be helpful if you include similar diffstat here as running 'git
> format-patch --cover-letter ...' generates.
>
> Anyway for patches 7-13,
>
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Thanks! This is much appreciated.

Could you also review the other related patches? There are just a few 
and they're relatively simple:

Set of three patches (which precedes what you reviewed):

<URL:http://www.spinics.net/lists/linux-acpi/msg72895.html>

And then finally:

<URL:http://www.spinics.net/lists/linux-acpi/msg72888.html>

-- 
Regards,

Sakari Ailus
sakari.ailus@linux.intel.com

Re: [PATCH v5 00/13] ACPI graph support

[Mika Westerberg]

On Mon, Mar 27, 2017 at 12:17:50AM +0300, Sakari Ailus wrote:
> Could you also review the other related patches? There are just a few and
> they're relatively simple:
> 
> Set of three patches (which precedes what you reviewed):
> 
> <URL:http://www.spinics.net/lists/linux-acpi/msg72895.html>
> 
> And then finally:
> 
> <URL:http://www.spinics.net/lists/linux-acpi/msg72888.html>

Sure, I'll go ahead and check those now.
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[PATCH v5 12/13] device property: Add fwnode_get_next_parent()

[Sakari Ailus]

In order to differentiate the functionality between dropping a reference
to the node (or not) for the benefit of OF, introduce
fwnode_get_next_parent().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/base/property.c  | 29 +++++++++++++++++++++++++++++
 include/linux/property.h |  1 +
 2 files changed, 30 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 09f348d..c1fed33 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -976,6 +976,35 @@ int device_add_properties(struct device *dev,
 EXPORT_SYMBOL_GPL(device_add_properties);
 
 /**
+ * fwnode_get_next_parent - Iterate to the node's parent
+ * @fwnode: Firmware whose parent is retrieved
+ *
+ * This is like fwnode_get_parent() except that it drops the refcount
+ * on the passed node, making it suitable for iterating through a
+ * node's parents.
+ *
+ * Returns a node pointer with refcount incremented, use
+ * fwnode_handle_node() on it when done.
+ */
+struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *parent = NULL;
+
+	if (is_of_node(fwnode)) {
+		struct device_node *node;
+
+		node = of_get_next_parent(to_of_node(fwnode));
+		if (node)
+			parent = &node->fwnode;
+	} else if (is_acpi_node(fwnode)) {
+		parent = acpi_node_get_parent(fwnode);
+	}
+
+	return parent;
+}
+EXPORT_SYMBOL_GPL(fwnode_get_next_parent);
+
+/**
  * fwnode_get_parent - Return parent firwmare node
  * @fwnode: Firmware whose parent is retrieved
  *
diff --git a/include/linux/property.h b/include/linux/property.h
index 3a4e435..2f48261 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -73,6 +73,7 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
 				 const char *propname, const char *string);
 
 struct fwnode_handle *fwnode_get_parent(struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode);
 struct fwnode_handle *fwnode_get_next_child_node(struct fwnode_handle *fwnode,
 						 struct fwnode_handle *child);
 
-- 
2.7.4

[PATCH v5.1 12/13] device property: Add fwnode_get_next_parent()

[Sakari Ailus]

In order to differentiate the functionality between dropping a reference
to the node (or not) for the benefit of OF, introduce
fwnode_get_next_parent().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
since v5:

- Call fwnode_get_parent() to get the parent, independently of the FW
  type. In other words, squashed "device property: Implement
  fwnode_get_next_parent() using fwnode interface" to this one.

 drivers/base/property.c  | 21 +++++++++++++++++++++
 include/linux/property.h |  1 +
 2 files changed, 22 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index a4fe66c..0a120e3 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -976,6 +976,27 @@ int device_add_properties(struct device *dev,
 EXPORT_SYMBOL_GPL(device_add_properties);
 
 /**
+ * fwnode_get_next_parent - Iterate to the node's parent
+ * @fwnode: Firmware whose parent is retrieved
+ *
+ * This is like fwnode_get_parent() except that it drops the refcount
+ * on the passed node, making it suitable for iterating through a
+ * node's parents.
+ *
+ * Returns a node pointer with refcount incremented, use
+ * fwnode_handle_node() on it when done.
+ */
+struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *parent = fwnode_get_parent(fwnode);
+
+	fwnode_handle_put(fwnode);
+
+	return parent;
+}
+EXPORT_SYMBOL_GPL(fwnode_get_next_parent);
+
+/**
  * fwnode_get_parent - Return parent firwmare node
  * @fwnode: Firmware whose parent is retrieved
  *
diff --git a/include/linux/property.h b/include/linux/property.h
index 3a4e435..2f48261 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -73,6 +73,7 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
 				 const char *propname, const char *string);
 
 struct fwnode_handle *fwnode_get_parent(struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode);
 struct fwnode_handle *fwnode_get_next_child_node(struct fwnode_handle *fwnode,
 						 struct fwnode_handle *child);
 
-- 
2.7.4

[PATCH v5 13/13] ACPI / DSD: Document references, ports and endpoints

[Sakari Ailus]

Document the use of references into the hierarchical data extension
structure, as well as the use of port and endpoint concepts that are very
similar to those in Devicetree.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 Documentation/acpi/dsd/graph.txt | 160 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 160 insertions(+)
 create mode 100644 Documentation/acpi/dsd/graph.txt

diff --git a/Documentation/acpi/dsd/graph.txt b/Documentation/acpi/dsd/graph.txt
new file mode 100644
index 0000000..064fa8a
--- /dev/null
+++ b/Documentation/acpi/dsd/graph.txt
@@ -0,0 +1,160 @@
+Graphs
+
+
+_DSD
+----
+
+_DSD (Device Specific Data) [7] is a predefined ACPI device
+configuration object that can be used to convey information on
+hardware features which are not specifically covered by the ACPI
+specification [1][6]. There are two _DSD extensions that are relevant
+for graphs: property [4] and hierarchical data extensions [5]. The
+property extension provides generic key-value pairs whereas the
+hierarchical data extension supports nodes with references to other
+nodes, forming a tree. The nodes in the tree may contain properties as
+defined by the property extension. The two extensions together provide
+a tree-like structure with zero or more properties (key-value pairs)
+in each node of the tree.
+
+The data structure may be accessed at runtime by using the device_*
+and fwnode_* functions defined in include/linux/fwnode.h .
+
+Fwnode represents a generic firmware node object. It is independent on
+the firmware type. In ACPI, fwnodes are _DSD hierarchical data
+extensions objects. A device's _DSD object is represented by an
+fwnode.
+
+The data structure may be referenced to elsewhere in the ACPI tables
+by using a hard reference to the device itself and an index to the
+hierarchical data extension array on each depth.
+
+
+Ports and endpoints
+-------------------
+
+The port and endpoint concepts are very similar to those in Devicetree
+[3]. A port represents an interface in a device, and an endpoint
+represents a connection to that interface.
+
+All port nodes are located under the device's "_DSD" node in the
+hierarchical data extension tree. The property extension related to
+each port node must contain the key "port" and an integer value which
+is the number of the port.
+
+Further on, endpoints are located under the individual port nodes. The
+first hierarchical data extension package list entry of the endpoint
+nodes must begin with "endpoint" and must be followed by the number
+of the endpoint.
+
+Each port node contains a property extension key "port", the value of
+which is the number of the port node. The each endpoint is similarly numbered
+with a property extension key "endpoint". Port numbers must be unique within a
+device and endpoint numbers must be unique within an endpoint.
+
+The endpoint reference uses property extension with "remote-endpoint" property
+name followed by a reference in the same package. Such references consist of the
+name of the remote device, number of the port in the device and finally the
+number of the endpoint in that port. Individual references thus appear as:
+
+    Package() { device, port_number, endpoint_number }
+
+The references to endpoints must be always done both ways, to the
+remote endpoint and back from the referred remote endpoint node.
+
+A simple example of this is show below:
+
+    Scope (\_SB.PCI0.I2C2)
+    {
+	Device (CAM0)
+	{
+	    Name (_DSD, Package () {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "compatible", Package () { "nokia,smia" } },
+		},
+		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+		Package () {
+		    Package () { "port0", "PRT0" },
+		}
+	    })
+	    Name (PRT0, Package() {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "port", 0 },
+		},
+		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+		Package () {
+		    Package () { "endpoint0", "EP0" },
+		}
+	    })
+	    Name (EP0, Package() {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "endpoint", 0 },
+		    Package () { "remote-endpoint", Package() { \_SB.PCI0.ISP, 4, 0 } },
+		}
+	    })
+	}
+    }
+
+    Scope (\_SB.PCI0)
+    {
+	Device (ISP)
+	{
+	    Name (_DSD, Package () {
+		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+		Package () {
+		    Package () { "port4", "PRT4" },
+		}
+	    })
+
+	    Name (PRT4, Package() {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "port", 4 }, /* CSI-2 port number */
+		},
+		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+		Package () {
+		    Package () { "endpoint0", "EP0" },
+		}
+	    })
+
+	    Name (EP0, Package() {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "endpoint", 0 },
+		    Package () { "remote-endpoint", Package () { \_SB.PCI0.I2C2.CAM0, 0, 0 } },
+		}
+	    })
+	}
+    }
+
+Here, the port 0 of the "CAM0" device is connected to the port 4 of
+the "ISP" device and vice versa.
+
+
+References
+----------
+
+[1] _DSD (Device Specific Data) Implementation Guide.
+    <URL:http://www.uefi.org/sites/default/files/resources/_DSD-implementation-guide-toplevel-1_1.htm>,
+    referenced 2016-10-03.
+
+[2] Devicetree. <URL:http://www.devicetree.org>, referenced 2016-10-03.
+
+[3] Documentation/devicetree/bindings/graph.txt
+
+[4] Device Properties UUID For _DSD.
+    <URL:http://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf>,
+    referenced 2016-10-04.
+
+[5] Hierarchical Data Extension UUID For _DSD.
+    <URL:http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.pdf>,
+    referenced 2016-10-04.
+
+[6] Advanced Configuration and Power Interface Specification.
+    <URL:http://www.uefi.org/sites/default/files/resources/ACPI_6_1.pdf>,
+    referenced 2016-10-04.
+
+[7] _DSD Device Properties Usage Rules.
+    Documentation/acpi/DSD-properties-rules.txt
-- 
2.7.4

[PATCH v5.1 13/13] ACPI / DSD: Document references, ports and endpoints

[Sakari Ailus]

Document the use of references into the hierarchical data extension
structure, as well as the use of port and endpoint concepts that are very
similar to those in Devicetree.

Signed-off-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
since v5:

- Clarify port and endpoint node object naming. Using both port and endpoint
  cleanly resolves object naming by using the appropriate port and
  endpoint numbers.

- Endpoint node numbers are unique within a port, not an endpoint.

The diff between v5 is below.

 diff --git a/Documentation/acpi/dsd/graph.txt b/Documentation/acpi/dsd/graph.txt
 new file mode 100644
-index 0000000..064fa8a
+index 0000000..ac09e31
 --- /dev/null
 +++ b/Documentation/acpi/dsd/graph.txt
-@@ -0,0 +1,160 @@
+@@ -0,0 +1,162 @@
 +Graphs
 +
 +
@@ -61,21 +60,23 @@
 +All port nodes are located under the device's "_DSD" node in the
 +hierarchical data extension tree. The property extension related to
 +each port node must contain the key "port" and an integer value which
-+is the number of the port.
++is the number of the port. The object it refers to should be called "PRTX",
++where "X" is the number of the port.
 +
 +Further on, endpoints are located under the individual port nodes. The
 +first hierarchical data extension package list entry of the endpoint
 +nodes must begin with "endpoint" and must be followed by the number
-+of the endpoint.
++of the endpoint. The object it refers to should be called "EPXY", where
++"X" is the number of the port and "Y" is the number of the endpoint.
 +
 +Each port node contains a property extension key "port", the value of
 +which is the number of the port node. The each endpoint is similarly numbered
 +with a property extension key "endpoint". Port numbers must be unique within a
-+device and endpoint numbers must be unique within an endpoint.
++device and endpoint numbers must be unique within a port.
 +
 +The endpoint reference uses property extension with "remote-endpoint" property
 +name followed by a reference in the same package. Such references consist of the
-+name of the remote device, number of the port in the device and finally the
++the remote device reference, number of the port in the device and finally the
 +number of the endpoint in that port. Individual references thus appear as:
 +
 +    Package() { device, port_number, endpoint_number }
@@ -106,10 +107,10 @@
 +		},
 +		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
 +		Package () {
-+		    Package () { "endpoint0", "EP0" },
++		    Package () { "endpoint0", "EP00" },
 +		}
 +	    })
-+	    Name (EP0, Package() {
++	    Name (EP00, Package() {
 +		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
 +		Package () {
 +		    Package () { "endpoint", 0 },
@@ -137,11 +138,11 @@
 +		},
 +		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
 +		Package () {
-+		    Package () { "endpoint0", "EP0" },
++		    Package () { "endpoint0", "EP40" },
 +		}
 +	    })
 +
-+	    Name (EP0, Package() {
++	    Name (EP40, Package() {
 +		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
 +		Package () {
 +		    Package () { "endpoint", 0 },

 Documentation/acpi/dsd/graph.txt | 162 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 162 insertions(+)
 create mode 100644 Documentation/acpi/dsd/graph.txt

diff --git a/Documentation/acpi/dsd/graph.txt b/Documentation/acpi/dsd/graph.txt
new file mode 100644
index 0000000..ac09e31
--- /dev/null
+++ b/Documentation/acpi/dsd/graph.txt
@@ -0,0 +1,162 @@
+Graphs
+
+
+_DSD
+----
+
+_DSD (Device Specific Data) [7] is a predefined ACPI device
+configuration object that can be used to convey information on
+hardware features which are not specifically covered by the ACPI
+specification [1][6]. There are two _DSD extensions that are relevant
+for graphs: property [4] and hierarchical data extensions [5]. The
+property extension provides generic key-value pairs whereas the
+hierarchical data extension supports nodes with references to other
+nodes, forming a tree. The nodes in the tree may contain properties as
+defined by the property extension. The two extensions together provide
+a tree-like structure with zero or more properties (key-value pairs)
+in each node of the tree.
+
+The data structure may be accessed at runtime by using the device_*
+and fwnode_* functions defined in include/linux/fwnode.h .
+
+Fwnode represents a generic firmware node object. It is independent on
+the firmware type. In ACPI, fwnodes are _DSD hierarchical data
+extensions objects. A device's _DSD object is represented by an
+fwnode.
+
+The data structure may be referenced to elsewhere in the ACPI tables
+by using a hard reference to the device itself and an index to the
+hierarchical data extension array on each depth.
+
+
+Ports and endpoints
+-------------------
+
+The port and endpoint concepts are very similar to those in Devicetree
+[3]. A port represents an interface in a device, and an endpoint
+represents a connection to that interface.
+
+All port nodes are located under the device's "_DSD" node in the
+hierarchical data extension tree. The property extension related to
+each port node must contain the key "port" and an integer value which
+is the number of the port. The object it refers to should be called "PRTX",
+where "X" is the number of the port.
+
+Further on, endpoints are located under the individual port nodes. The
+first hierarchical data extension package list entry of the endpoint
+nodes must begin with "endpoint" and must be followed by the number
+of the endpoint. The object it refers to should be called "EPXY", where
+"X" is the number of the port and "Y" is the number of the endpoint.
+
+Each port node contains a property extension key "port", the value of
+which is the number of the port node. The each endpoint is similarly numbered
+with a property extension key "endpoint". Port numbers must be unique within a
+device and endpoint numbers must be unique within a port.
+
+The endpoint reference uses property extension with "remote-endpoint" property
+name followed by a reference in the same package. Such references consist of the
+the remote device reference, number of the port in the device and finally the
+number of the endpoint in that port. Individual references thus appear as:
+
+    Package() { device, port_number, endpoint_number }
+
+The references to endpoints must be always done both ways, to the
+remote endpoint and back from the referred remote endpoint node.
+
+A simple example of this is show below:
+
+    Scope (\_SB.PCI0.I2C2)
+    {
+	Device (CAM0)
+	{
+	    Name (_DSD, Package () {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "compatible", Package () { "nokia,smia" } },
+		},
+		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+		Package () {
+		    Package () { "port0", "PRT0" },
+		}
+	    })
+	    Name (PRT0, Package() {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "port", 0 },
+		},
+		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+		Package () {
+		    Package () { "endpoint0", "EP00" },
+		}
+	    })
+	    Name (EP00, Package() {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "endpoint", 0 },
+		    Package () { "remote-endpoint", Package() { \_SB.PCI0.ISP, 4, 0 } },
+		}
+	    })
+	}
+    }
+
+    Scope (\_SB.PCI0)
+    {
+	Device (ISP)
+	{
+	    Name (_DSD, Package () {
+		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+		Package () {
+		    Package () { "port4", "PRT4" },
+		}
+	    })
+
+	    Name (PRT4, Package() {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "port", 4 }, /* CSI-2 port number */
+		},
+		ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+		Package () {
+		    Package () { "endpoint0", "EP40" },
+		}
+	    })
+
+	    Name (EP40, Package() {
+		ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+		Package () {
+		    Package () { "endpoint", 0 },
+		    Package () { "remote-endpoint", Package () { \_SB.PCI0.I2C2.CAM0, 0, 0 } },
+		}
+	    })
+	}
+    }
+
+Here, the port 0 of the "CAM0" device is connected to the port 4 of
+the "ISP" device and vice versa.
+
+
+References
+----------
+
+[1] _DSD (Device Specific Data) Implementation Guide.
+    <URL:http://www.uefi.org/sites/default/files/resources/_DSD-implementation-guide-toplevel-1_1.htm>,
+    referenced 2016-10-03.
+
+[2] Devicetree. <URL:http://www.devicetree.org>, referenced 2016-10-03.
+
+[3] Documentation/devicetree/bindings/graph.txt
+
+[4] Device Properties UUID For _DSD.
+    <URL:http://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf>,
+    referenced 2016-10-04.
+
+[5] Hierarchical Data Extension UUID For _DSD.
+    <URL:http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.pdf>,
+    referenced 2016-10-04.
+
+[6] Advanced Configuration and Power Interface Specification.
+    <URL:http://www.uefi.org/sites/default/files/resources/ACPI_6_1.pdf>,
+    referenced 2016-10-04.
+
+[7] _DSD Device Properties Usage Rules.
+    Documentation/acpi/DSD-properties-rules.txt
-- 
2.7.4

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