Subject: [PATCH] [acpi driver model] Update sysfs support

- Add acpi_dev_show() and acpi_dev_store() methods that will
  forward calls down to the real show/store methods
- Add create_one() and remove_one() helpers that check for
  (and call if necessary) the ->ad_test() method; also fill
  in the ->ad_show() and ->ad_store() methods.
- Fix acpi_sysfs_device_register() so that we only remove
  the attributes that have been added if one fails to be
  created (instead of trying to remove all of them).
- Update comments.

Signed-off-by: Patrick Mochel <mochel@linux.intel.com>

---

 drivers/acpi/drivers/core/sysfs.c |  125 +++++++++++++++++++++++++++++++++----
 1 files changed, 113 insertions(+), 12 deletions(-)

applies-to: 707209fffa694e9df00ee82733e188d4ce29089b
57ea0b929e7b3de1c15ac89d715c2ea27d12b72c
diff --git a/drivers/acpi/drivers/core/sysfs.c b/drivers/acpi/drivers/core/sysfs.c
index f442d50..efd295e 100644
--- a/drivers/acpi/drivers/core/sysfs.c
+++ b/drivers/acpi/drivers/core/sysfs.c
@@ -79,32 +79,133 @@ static struct acpi_dev_attr acpi_dev_att
 };
 
 
+
+static struct acpi_dev_attr * to_ada(struct device_attribute * da)
+{
+	return container_of(da, struct acpi_dev_attr, ad_attr);
+}
+
+static ssize_t acpi_dev_show(struct device * dev, 
+			     struct device_attribute * attr,
+			     char * buf)
+{
+	struct acpi_dev * ad = to_acpi_dev(dev);
+	struct acpi_dev_attr * ada = to_ada(attr);
+	ssize_t ret = 0;
+
+	if (ad) {
+		if (ada->ad_show)
+			ret = ada->ad_show(ad, buf);
+	} else
+		ret = -ENODEV;
+	return ret;
+}
+
+
+static ssize_t acpi_dev_store(struct device * dev, 
+			      struct device_attribute * attr,
+			      const char * buf, size_t len)
+{
+	struct acpi_dev * ad = to_acpi_dev(dev);
+	struct acpi_dev_attr * ada = to_ada(attr);
+	ssize_t ret = 0;
+
+	if (ad) {
+		if (ada->ad_store)
+			ret = ada->ad_store(ad, buf, len);
+	} else
+		ret = -ENODEV;
+	return ret;
+}
+
+/**
+ *	create_one - Add a single sysfs file for an ACPI device.
+ *	@ad:	The ACPI device
+ *	@a:	The attribute that we may be adding.
+ *
+ *	Check for a test function, and if 
+ *	- it's not there, or
+ *	- it's there, and returns TRUE (1)
+ *	Then fill in the read and/or write methods and add the file.
+ */
+
+static int create_one(struct acpi_dev * ad, struct acpi_dev_attr * a)
+{
+	int ret = 0;
+
+	if (!a->ad_test || (a->ad_test && a->ad_test(ad))) {
+		if (a->ad_attr.attr.mode & S_IRUGO)
+			a->ad_attr.show = acpi_dev_show;
+		if (a->ad_attr.attr.mode & S_IWUGO)
+			a->ad_attr.store = acpi_dev_store;
+		ret = device_create_file(&ad->dev, &a->ad_attr);
+	}
+	return ret;
+}
+
+
+/**
+ *	remove_one - Remove a single file for a device
+ *	@ad:	The ACPI device
+ *	@a:	The attribute we may be removing.
+ *
+ *	Check for a test function, and if
+ *	- it doesn't exist, or
+ *	- it exists and returns TRUE (1)
+ *	Then remove the file.
+ */
+
+static void remove_one(struct acpi_dev * ad, struct acpi_dev_attr * a)
+{
+	if (!a->ad_test || (a->ad_test && a->ad_test(ad)))
+		device_remove_file(&ad->dev, &a->ad_attr);
+}
+
+
+/**
+ *	acpi_sysfs_device_unregister - Remove default sysfs files
+ *	@ad:	The ACPI device we're removing files for.
+ *
+ *	Loop over the default attributes (defined above) and call 
+ *	remove_one() for each.
+ */
+
 void acpi_sysfs_device_unregister(struct acpi_dev * ad)
 {
 	int num = ARRAY_SIZE(acpi_dev_attrs);
 	int i;
 
-	for (i = 0; i < num; i++) {
-		if (acpi_dev_attrs[i].ad_test(ad))
-			device_remove_file(&ad->dev, &acpi_dev_attrs[i].ad_attr);
-	}
+	for (i = 0; i < num; i++)
+		remove_one(ad, &acpi_dev_attrs[i]);
 }
 
+
+/**
+ *	acpi_sysfs_device_register - Add default sysfs files
+ *	@ad:	The ACPI device we're removing files for.
+ *
+ *	Loop over the default attributes (defined above) and call 
+ *	create_one() for each.
+ *
+ *	If one fails, remove the ones that we've added so far.
+ */
+
 int acpi_sysfs_device_register(struct acpi_dev * ad)
 {
 	int num = ARRAY_SIZE(acpi_dev_attrs);
-	int i;
 	int ret = 0;
+	int i;
 
 	for (i = 0; i < num; i++) {
-		if (acpi_dev_attrs[i].ad_test(ad)) {
-			ret = device_create_file(&ad->dev, &acpi_dev_attrs[i].ad_attr);
-			if (ret) {
-				acpi_sysfs_device_unregister(ad);
-				break;
-			}
-		}
+		ret = create_one(ad, &acpi_dev_attrs[i]);
+		if (ret)
+			goto Fail;
 	}
+	return 0;
+
+ Fail:
+	while (--i > 0)
+		remove_one(ad, &acpi_dev_attrs[i]);
 	return ret;
 }
 
---
0.99.9.GIT