Messages in this thread Patch in this message | | | Date | Tue, 22 Apr 2008 20:18:03 +0900 | From | KaiGai Kohei <> | Subject | [PATCH 3/3] a new example to use kobject/kobj_attribute |
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[PATCH 3/3] a new example to use kobject/kobj_attribute
This patch can provide a new exmple to use kobject and attribute. The _show() and _store() method can refer/store the private data field of kobj_attribute structure to know what entries are accessed by users. It will make easier to share a single _show()/_store() method with several entries.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> -- samples/kobject/kobject-example.c | 32 ++++++++++++++++++++++++++++++++ 1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/samples/kobject/kobject-example.c b/samples/kobject/kobject-example.c index 08d0d3f..5486a14 100644 --- a/samples/kobject/kobject-example.c +++ b/samples/kobject/kobject-example.c @@ -77,6 +77,35 @@ static struct kobj_attribute baz_attribute = static struct kobj_attribute bar_attribute = __ATTR(bar, 0666, b_show, b_store);
+/* + * You can store a private data within 'data' field of kobj_attribute. + * It enables to share a single _show() or _store() method with several + * entries. + */ +static ssize_t integer_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return scnprintf(buf, PAGE_SIZE, "%ld\n", (long) attr->data); +} + +static ssize_t integer_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + long code; + + sscanf(buf, "%ld", &code); + attr->data = (void *) code; + return count; +} + +static struct kobj_attribute hoge_attribute = + __ATTR_DATA(hoge, 0666, integer_show, integer_store, (long) 123); +static struct kobj_attribute piyo_attribute = + __ATTR_DATA(piyo, 0666, integer_show, integer_store, (long) 456); +static struct kobj_attribute fuga_attribute = + __ATTR_DATA(fuga, 0444, integer_show, NULL, (long) 789);
/* * Create a group of attributes so that we can create and destory them all @@ -86,6 +115,9 @@ static struct attribute *attrs[] = { &foo_attribute.attr, &baz_attribute.attr, &bar_attribute.attr, + &hoge_attribute.attr, + &piyo_attribute.attr, + &fuga_attribute.attr, NULL, /* need to NULL terminate the list of attributes */ };
-- OSS Platform Development Division, NEC KaiGai Kohei <kaigai@ak.jp.nec.com>
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