lkml.org 
[lkml]   [2013]   [Dec]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
SubjectRe: [PATCHv6+ 01/13] of: introduce of_property_for_earch_phandle_with_args()
Hi Grant,

Grant Likely <grant.likely@linaro.org> wrote @ Wed, 11 Dec 2013 14:28:45 +0100:

> On Thu, 21 Nov 2013 11:57:00 -0700, Stephen Warren <swarren@wwwdotorg.org> wrote:
> > On 11/21/2013 10:17 AM, Hiroshi Doyu wrote:
> > > Iterating over a property containing a list of phandles with arguments
> > > is a common operation for device drivers. This patch adds a new
> > > of_property_for_each_phandle_with_args() macro to make the iteration
> > > simpler.
> > >
> > > Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
> > > ---
> > > v6+:
> > > Use the description, which Grant Likely proposed, to be full enough
> > > that a future reader can figure out why a patch was written.
> > > http://lists.linuxfoundation.org/pipermail/iommu/2013-November/007062.html
...

> That's right, I forgot I said that. Yes please fix the implementation.

Here's the latest. I'll include this with the next v7 series.

Can I get your Acked-by with this?

--8<----

From 8f7c0404aa68f0e8dbe0babc240590f6528ecc1f Mon Sep 17 00:00:00 2001
From: Hiroshi Doyu <hdoyu@nvidia.com>
Date: Fri, 15 Nov 2013 10:52:53 +0200
Subject: [PATCH] of: introduce of_property_for_each_phandle_with_args()

Iterating over a property containing a list of phandles with arguments
is a common operation for device drivers. This patch adds a new
of_property_for_each_phandle_with_args() macro to make the iteration
simpler.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Cc: Rob Herring <robherring2@gmail.com>
---
v7:
Fixed some minors pointed by Rob and Stephen.

v6++++:
Iterate without intrducing a new struct.

v6+++:
Introduced a new struct "of_phandle_iter" to keep the state when
iterating over the list.

v6++:
Optimized to avoid O(n^2), suggested by Stephen Warren.
http://lists.linuxfoundation.org/pipermail/iommu/2013-November/007066.html

I didn't introduce any struct to hold params and state here.

v6+:
Use the description, which Grant Likely proposed, to be full enough
that a future reader can figure out why a patch was written.

v5:
New patch for v5.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
---
drivers/of/base.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 32 ++++++++++++++++++++++++++++++++
2 files changed, 78 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index f807d0e..cd4ab05 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1201,6 +1201,52 @@ void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
printk("\n");
}

+const __be32 *of_phandle_iter_next(const char *cells_name, int cell_count,
+ const __be32 *cur, const __be32 *end,
+ struct of_phandle_args *out_args)
+{
+ struct device_node *dn;
+ int i;
+
+ if (!cells_name && !cell_count)
+ return NULL;
+
+ if (!cur || (cur >= end))
+ return NULL;
+
+ dn = of_find_node_by_phandle(be32_to_cpup(cur++));
+ if (!dn)
+ return NULL;
+
+ if (cells_name)
+ if (of_property_read_u32(dn, cells_name, &cell_count))
+ return NULL;
+
+ out_args->np = dn;
+ out_args->args_count = cell_count;
+ for (i = 0; i < cell_count; i++)
+ out_args->args[i] = be32_to_cpup(cur++);
+
+ return cur;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iter_next);
+
+const __be32 *of_phandle_iter_init(const struct device_node *np,
+ const char *list_name,
+ const __be32 **end)
+{
+ size_t bytes;
+ const __be32 *cur;
+
+ cur = of_get_property(np, list_name, &bytes);
+ *end = cur;
+ if (bytes)
+ *end += bytes / sizeof(*cur);
+
+ return cur;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iter_init);
+
static int __of_parse_phandle_with_args(const struct device_node *np,
const char *list_name,
const char *cells_name,
diff --git a/include/linux/of.h b/include/linux/of.h
index 276c546..4345582 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -303,6 +303,14 @@ extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
extern int of_count_phandle_with_args(const struct device_node *np,
const char *list_name, const char *cells_name);

+extern const __be32 *of_phandle_iter_init(const struct device_node *np,
+ const char *list_name,
+ const __be32 **end);
+extern const __be32 *of_phandle_iter_next(const char *cells_name,
+ int cell_count,
+ const __be32 *cur, const __be32 *end,
+ struct of_phandle_args *out_args);
+
extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align));
extern int of_alias_get_id(struct device_node *np, const char *stem);

@@ -527,6 +535,22 @@ static inline int of_count_phandle_with_args(struct device_node *np,
return -ENOSYS;
}

+static inline const __be32 *of_phandle_iter_init(const struct device_node *np,
+ const char *list_name,
+ const __be32 **end)
+{
+ return NULL;
+}
+
+static inline const __be32 *of_phandle_iter_next(const char *cells_name,
+ int cell_count,
+ const __be32 *cur,
+ const __be32 *end,
+ struct of_phandle_args *out_args);
+{
+ return NULL;
+}
+
static inline int of_alias_get_id(struct device_node *np, const char *stem)
{
return -ENOSYS;
@@ -613,6 +637,14 @@ static inline int of_property_read_u32(const struct device_node *np,
s; \
s = of_prop_next_string(prop, s))

+#define of_property_for_each_phandle_with_args(node, list_name, cells_name, \
+ cell_count, out_args, cur, end) \
+ for (cur = of_phandle_iter_init(node, list_name, &end), \
+ cur = of_phandle_iter_next(cells_name, cell_count, \
+ cur, end, &out_args); \
+ cur; \
+ cur = of_phandle_iter_next(cells_name, cell_count, cur, end, &out_args))
+
#if defined(CONFIG_PROC_FS) && defined(CONFIG_PROC_DEVICETREE)
extern void proc_device_tree_add_node(struct device_node *, struct proc_dir_entry *);
extern void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop);
--
1.8.1.5

\
 
 \ /
  Last update: 2013-12-11 15:01    [W:0.141 / U:0.296 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site