diff mbox series

[v2,06/12] software_node: Add support for fwnode_graph*() family of functions

Message ID 20201217234337.1983732-7-djrscally@gmail.com
State New
Headers show
Series Add functionality to ipu3-cio2 driver allowing software_node connections to sensors on platforms designed for Windows | expand

Commit Message

Daniel Scally Dec. 17, 2020, 11:43 p.m. UTC
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>

This implements the remaining .graph_* callbacks in the
fwnode operations structure for the software nodes. That makes
the fwnode_graph*() functions available in the drivers also
when software nodes are used.

The implementation tries to mimic the "OF graph" as much as
possible, but there is no support for the "reg" device
property. The ports will need to have the index in their
name which starts with "port@" (for example "port@0", "port@1",
...) and endpoints will use the index of the software node
that is given to them during creation. The port nodes can
also be grouped under a specially named "ports" subnode,
just like in DT, if necessary.

The remote-endpoints are reference properties under the
endpoint nodes that are named "remote-endpoint".

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Co-developed-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
---
Changes in v2:

	- Changed commit to specify port name prefix as port@
	- Accounted for that rename in *parse_endpoint()

 drivers/base/swnode.c | 110 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 109 insertions(+), 1 deletion(-)

Comments

Andy Shevchenko Dec. 18, 2020, 8:37 p.m. UTC | #1
On Thu, Dec 17, 2020 at 11:43:31PM +0000, Daniel Scally wrote:
> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> 
> This implements the remaining .graph_* callbacks in the
> fwnode operations structure for the software nodes. That makes
> the fwnode_graph*() functions available in the drivers also
> when software nodes are used.
> 
> The implementation tries to mimic the "OF graph" as much as
> possible, but there is no support for the "reg" device
> property. The ports will need to have the index in their
> name which starts with "port@" (for example "port@0", "port@1",
> ...) and endpoints will use the index of the software node
> that is given to them during creation. The port nodes can
> also be grouped under a specially named "ports" subnode,
> just like in DT, if necessary.
> 
> The remote-endpoints are reference properties under the
> endpoint nodes that are named "remote-endpoint".

...

> +	while ((port = software_node_get_next_child(parent, old))) {
> +		if (!strncmp(to_swnode(port)->node->name, "port", 4))
> +			return port;
> +		old = port;
> +	}

Dunno if we need defines for port and its length here.

...

> +	ret = kstrtou32(swnode->parent->node->name + 5, 10, &endpoint->port);

But here at least comment is needed what 5 means ('port@' I suppose).

> +	if (ret)
> +		return ret;
Daniel Scally Dec. 21, 2020, 10:01 a.m. UTC | #2
Hi Sakari - thanks for the reviews in previous emails

On 21/12/2020 09:34, Sakari Ailus wrote:
> Hi Daniel and Heikki,
>
> On Thu, Dec 17, 2020 at 11:43:31PM +0000, Daniel Scally wrote:
>
> +static struct fwnode_handle *
> +software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
> +{
> +	struct swnode *swnode = to_swnode(fwnode);
> +	struct fwnode_handle *parent;
> +
> +	if (!strcmp(swnode->parent->node->name, "ports"))
> +		parent = &swnode->parent->parent->fwnode;
> +	else
> +		parent = &swnode->parent->fwnode;
> If you happen to call this function on a non-port node for whatever reason,
> you may end up accessing a pointer that's NULL, can't you?

Yes, actually.

> Instead I'd do
> something like:
>
> swnode = swnode->parent;
> if (swnode && !strcmp(swnode->node->name, "ports"))
> 	swnode = swnode->parent;
>
> return swnode ? software_node_get(&swnode->fwnode) : NULL;
>
> You can also drop parent as a by-product of this.
Yes ok, that looks good to me - thanks.
>> +
>> +	return software_node_get(parent);
>> +}
>> +
>> +static int
>> +software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
>> +				   struct fwnode_endpoint *endpoint)
>> +{
>> +	struct swnode *swnode = to_swnode(fwnode);
>> +	int ret;
>> +
>> +	ret = kstrtou32(swnode->parent->node->name + 5, 10, &endpoint->port);
>> +	if (ret)
>> +		return ret;
>> +
>> +	endpoint->id = swnode->id;
>> +	endpoint->local_fwnode = fwnode;
>> +
>> +	return 0;
>> +}
>> +
>>  static const struct fwnode_operations software_node_ops = {
>>  	.get = software_node_get,
>>  	.put = software_node_put,
>> @@ -551,7 +655,11 @@ static const struct fwnode_operations software_node_ops = {
>>  	.get_parent = software_node_get_parent,
>>  	.get_next_child_node = software_node_get_next_child,
>>  	.get_named_child_node = software_node_get_named_child_node,
>> -	.get_reference_args = software_node_get_reference_args
>> +	.get_reference_args = software_node_get_reference_args,
>> +	.graph_get_next_endpoint = software_node_graph_get_next_endpoint,
>> +	.graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
>> +	.graph_get_port_parent = software_node_graph_get_port_parent,
>> +	.graph_parse_endpoint = software_node_graph_parse_endpoint,
>>  };
>>  
>>  /* -------------------------------------------------------------------------- */
diff mbox series

Patch

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 2b90d380039b..0d14d5ebe441 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -540,6 +540,110 @@  software_node_get_reference_args(const struct fwnode_handle *fwnode,
 	return 0;
 }
 
+static struct fwnode_handle *
+swnode_graph_find_next_port(const struct fwnode_handle *parent,
+			    struct fwnode_handle *port)
+{
+	struct fwnode_handle *old = port;
+
+	while ((port = software_node_get_next_child(parent, old))) {
+		if (!strncmp(to_swnode(port)->node->name, "port", 4))
+			return port;
+		old = port;
+	}
+
+	return NULL;
+}
+
+static struct fwnode_handle *
+software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
+				      struct fwnode_handle *endpoint)
+{
+	struct swnode *swnode = to_swnode(fwnode);
+	struct fwnode_handle *old = endpoint;
+	struct fwnode_handle *parent;
+	struct fwnode_handle *port;
+
+	if (!swnode)
+		return NULL;
+
+	if (endpoint) {
+		port = software_node_get_parent(endpoint);
+		parent = software_node_get_parent(port);
+	} else {
+		parent = software_node_get_named_child_node(fwnode, "ports");
+		if (!parent)
+			parent = software_node_get(&swnode->fwnode);
+
+		port = swnode_graph_find_next_port(parent, NULL);
+	}
+
+	for (; port; port = swnode_graph_find_next_port(parent, port)) {
+		endpoint = software_node_get_next_child(port, old);
+		if (endpoint) {
+			fwnode_handle_put(port);
+			break;
+		}
+
+		/* No more endpoints for that port, so stop passing old */
+		old = NULL;
+	}
+
+	fwnode_handle_put(parent);
+
+	return endpoint;
+}
+
+static struct fwnode_handle *
+software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
+{
+	struct swnode *swnode = to_swnode(fwnode);
+	const struct software_node_ref_args *ref;
+	const struct property_entry *prop;
+
+	if (!swnode)
+		return NULL;
+
+	prop = property_entry_get(swnode->node->properties, "remote-endpoint");
+	if (!prop || prop->type != DEV_PROP_REF || prop->is_inline)
+		return NULL;
+
+	ref = prop->pointer;
+
+	return software_node_get(software_node_fwnode(ref[0].node));
+}
+
+static struct fwnode_handle *
+software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
+{
+	struct swnode *swnode = to_swnode(fwnode);
+	struct fwnode_handle *parent;
+
+	if (!strcmp(swnode->parent->node->name, "ports"))
+		parent = &swnode->parent->parent->fwnode;
+	else
+		parent = &swnode->parent->fwnode;
+
+	return software_node_get(parent);
+}
+
+static int
+software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
+				   struct fwnode_endpoint *endpoint)
+{
+	struct swnode *swnode = to_swnode(fwnode);
+	int ret;
+
+	ret = kstrtou32(swnode->parent->node->name + 5, 10, &endpoint->port);
+	if (ret)
+		return ret;
+
+	endpoint->id = swnode->id;
+	endpoint->local_fwnode = fwnode;
+
+	return 0;
+}
+
 static const struct fwnode_operations software_node_ops = {
 	.get = software_node_get,
 	.put = software_node_put,
@@ -551,7 +655,11 @@  static const struct fwnode_operations software_node_ops = {
 	.get_parent = software_node_get_parent,
 	.get_next_child_node = software_node_get_next_child,
 	.get_named_child_node = software_node_get_named_child_node,
-	.get_reference_args = software_node_get_reference_args
+	.get_reference_args = software_node_get_reference_args,
+	.graph_get_next_endpoint = software_node_graph_get_next_endpoint,
+	.graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
+	.graph_get_port_parent = software_node_graph_get_port_parent,
+	.graph_parse_endpoint = software_node_graph_parse_endpoint,
 };
 
 /* -------------------------------------------------------------------------- */