diff mbox

[V2,3/5] of: introduce of_parse_phandle_with_fixed_args

Message ID 1373913629-32179-3-git-send-email-swarren@wwwdotorg.org (mailing list archive)
State New, archived
Headers show

Commit Message

Stephen Warren July 15, 2013, 6:40 p.m. UTC 
From: Stephen Warren <swarren@nvidia.com>

This is identical to of_parse_phandle_with_args(), except that the
number of argument cells is fixed, rather than being parsed out of the
node referenced by each phandle.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
 drivers/of/base.c  | 67 ++++++++++++++++++++++++++++++++++++++++++++++--------
 include/linux/of.h | 10 ++++++++
 2 files changed, 68 insertions(+), 9 deletions(-)

Comments

Sergei Shtylyov July 15, 2013, 6:59 p.m. UTC | #1 
On 07/15/2013 10:40 PM, Stephen Warren wrote:

> From: Stephen Warren <swarren@nvidia.com>

> This is identical to of_parse_phandle_with_args(), except that the
> number of argument cells is fixed, rather than being parsed out of the
> node referenced by each phandle.

> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> ---
>   drivers/of/base.c  | 67 ++++++++++++++++++++++++++++++++++++++++++++++--------
>   include/linux/of.h | 10 ++++++++
>   2 files changed, 68 insertions(+), 9 deletions(-)

> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 23e7073..ad799d9 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -1106,7 +1106,8 @@ EXPORT_SYMBOL(of_parse_phandle);
>
>   static int __of_parse_phandle_with_args(const struct device_node *np,
>   					const char *list_name,
> -					const char *cells_name, int index,
> +					const char *cells_name,
> +					int cells_count, int index,

    The correct grammar would be 'cell_name' and 'cell_count' I think.

>   					struct of_phandle_args *out_args)
>   {
>   	const __be32 *list, *list_end;
> @@ -1142,12 +1143,17 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
>   					 np->full_name);
>   				goto err;
>   			}
> -			if (of_property_read_u32(node, cells_name, &count)) {
> -				pr_err("%s: could not get %s for %s\n",
> -					 np->full_name, cells_name,
> -					 node->full_name);
> -				goto err;
> -			}
> +
> +			if (cells_name) {
> +				if (of_property_read_u32(node, cells_name,
> +							 &count)) {
> +					pr_err("%s: could not get %s for %s\n",
> +						np->full_name, cells_name,
> +						node->full_name);
> +					goto err;
> +				}
> +			} else
> +				count = cells_count;

    According to Documentation/CodingStyle chapter 3, both arms of the 
*if* statment should have {} if oe arm has it.

WBR, Sergei
Stephen Warren July 15, 2013, 11:06 p.m. UTC | #2 
On 07/15/2013 12:59 PM, Sergei Shtylyov wrote:
> On 07/15/2013 10:40 PM, Stephen Warren wrote:
> 
>> From: Stephen Warren <swarren@nvidia.com>
> 
>> This is identical to of_parse_phandle_with_args(), except that the
>> number of argument cells is fixed, rather than being parsed out of the
>> node referenced by each phandle.

>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>> index 23e7073..ad799d9 100644
>> --- a/drivers/of/base.c
>> +++ b/drivers/of/base.c
>> @@ -1106,7 +1106,8 @@ EXPORT_SYMBOL(of_parse_phandle);
>>
>>   static int __of_parse_phandle_with_args(const struct device_node *np,
>>                       const char *list_name,
>> -                    const char *cells_name, int index,
>> +                    const char *cells_name,
>> +                    int cells_count, int index,
> 
>    The correct grammar would be 'cell_name' and 'cell_count' I think.

I guess I can see the argument for cell_count, but "cells_name" is named
based on the DT property named "gpio-cells", so "cells" seems correct
here (and is a pre-existing issue anyway).

I'll fix up cell_count and the brace issue locally, but hold off reposting.
diff mbox

Patch

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 23e7073..ad799d9 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1106,7 +1106,8 @@  EXPORT_SYMBOL(of_parse_phandle);
 
 static int __of_parse_phandle_with_args(const struct device_node *np,
 					const char *list_name,
-					const char *cells_name, int index,
+					const char *cells_name,
+					int cells_count, int index,
 					struct of_phandle_args *out_args)
 {
 	const __be32 *list, *list_end;
@@ -1142,12 +1143,17 @@  static int __of_parse_phandle_with_args(const struct device_node *np,
 					 np->full_name);
 				goto err;
 			}
-			if (of_property_read_u32(node, cells_name, &count)) {
-				pr_err("%s: could not get %s for %s\n",
-					 np->full_name, cells_name,
-					 node->full_name);
-				goto err;
-			}
+
+			if (cells_name) {
+				if (of_property_read_u32(node, cells_name,
+							 &count)) {
+					pr_err("%s: could not get %s for %s\n",
+						np->full_name, cells_name,
+						node->full_name);
+					goto err;
+				}
+			} else
+				count = cells_count;
 
 			/*
 			 * Make sure that the arguments actually fit in the
@@ -1244,11 +1250,53 @@  int of_parse_phandle_with_args(const struct device_node *np, const char *list_na
 {
 	if (index < 0)
 		return -EINVAL;
-	return __of_parse_phandle_with_args(np, list_name, cells_name, index, out_args);
+	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
+					    index, out_args);
 }
 EXPORT_SYMBOL(of_parse_phandle_with_args);
 
 /**
+ * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cells_count: number of argument cells following the phandle
+ * @index:	index of a phandle to parse out
+ * @out_args:	optional pointer to output arguments structure (will be filled)
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ * Returns 0 on success and fills out_args, on error returns appropriate
+ * errno value.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->node
+ * pointer.
+ *
+ * Example:
+ *
+ * phandle1: node1 {
+ * }
+ *
+ * phandle2: node2 {
+ * }
+ *
+ * node3 {
+ * 	list = <&phandle1 0 2 &phandle2 2 3>;
+ * }
+ *
+ * To get a device_node of the `node2' node you may call this:
+ * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
+ */
+int of_parse_phandle_with_fixed_args(const struct device_node *np,
+				const char *list_name, int cells_count,
+				int index, struct of_phandle_args *out_args)
+{
+	if (index < 0)
+		return -EINVAL;
+	return __of_parse_phandle_with_args(np, list_name, NULL, cells_count,
+					   index, out_args);
+}
+EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
+
+/**
  * of_count_phandle_with_args() - Find the number of phandles references in a property
  * @np:		pointer to a device tree node containing a list
  * @list_name:	property name that contains a list
@@ -1266,7 +1314,8 @@  EXPORT_SYMBOL(of_parse_phandle_with_args);
 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
 				const char *cells_name)
 {
-	return __of_parse_phandle_with_args(np, list_name, cells_name, -1, NULL);
+	return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
+					    NULL);
 }
 EXPORT_SYMBOL(of_count_phandle_with_args);
 
diff --git a/include/linux/of.h b/include/linux/of.h
index 1fd08ca..0c457f5 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -280,6 +280,9 @@  extern struct device_node *of_parse_phandle(const struct device_node *np,
 extern int of_parse_phandle_with_args(const struct device_node *np,
 	const char *list_name, const char *cells_name, int index,
 	struct of_phandle_args *out_args);
+extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
+	const char *list_name, int cells_count, int index,
+	struct of_phandle_args *out_args);
 extern int of_count_phandle_with_args(const struct device_node *np,
 	const char *list_name, const char *cells_name);
 
@@ -488,6 +491,13 @@  static inline int of_parse_phandle_with_args(struct device_node *np,
 	return -ENOSYS;
 }
 
+static inline int of_parse_phandle_with_fixed_args(const struct device_node *np,
+	const char *list_name, int cells_count, int index,
+	struct of_phandle_args *out_args)
+{
+	return -ENOSYS;
+}
+
 static inline int of_count_phandle_with_args(struct device_node *np,
 					     const char *list_name,
 					     const char *cells_name)