staging: unisys: Clean up device sysfs attributes

Properly hook into the struct device groups element.  This allows the
core infrastructure to manage the files instead of the bus layer.  And
makes the code easier to read.

I didn't clean up the _show functions just modified them a bit to handle
the different args for now and to prevent a build warning.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/include/visorbus.h

@@ -128,7 +128,6 @@ struct visor_device {
 	struct periodic_work *periodic_work;
 	bool being_removed;
 	bool responded_to_device_create;
-	struct kobject kobjchannel;	/* visorbus<x>/dev<y>/channel/ */
 	struct kobject kobjdevmajorminor; /* visorbus<x>/dev<y>/devmajorminor/*/
 	struct {
 		int major, minor;

drivers/staging/unisys/visorbus/visorbus_main.c

@@ -396,214 +396,134 @@ unregister_devmajorminor_attributes(struct visor_device *dev)
 	dev->kobjdevmajorminor.parent = NULL;
 }
 
-/* Implement publishing of channel attributes under:
- *
- *     /sys/bus/visorbus<x>/dev<y>/channel
- *
- */
-
-#define to_channel_attr(_attr) \
-	container_of(_attr, struct channel_attribute, attr)
-#define to_visor_device_from_kobjchannel(obj) \
-	container_of(obj, struct visor_device, kobjchannel)
-
-struct channel_attribute {
-	struct attribute attr;
-	 ssize_t (*show)(struct visor_device*, char *buf);
-	 ssize_t (*store)(struct visor_device*, const char *buf, size_t count);
-};
-
 /* begin implementation of specific channel attributes to appear under
 * /sys/bus/visorbus<x>/dev<y>/channel
 */
-static ssize_t devicechannel_attr_physaddr(struct visor_device *dev, char *buf)
+static ssize_t physaddr_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
 {
-	if (!dev->visorchannel)
+	struct visor_device *vdev = to_visor_device(dev);
+
+	if (!vdev->visorchannel)
 		return 0;
 	return snprintf(buf, PAGE_SIZE, "0x%Lx\n",
-			visorchannel_get_physaddr(dev->visorchannel));
+			visorchannel_get_physaddr(vdev->visorchannel));
 }
 
-static ssize_t devicechannel_attr_nbytes(struct visor_device *dev, char *buf)
+static ssize_t nbytes_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
 {
-	if (!dev->visorchannel)
+	struct visor_device *vdev = to_visor_device(dev);
+
+	if (!vdev->visorchannel)
 		return 0;
 	return snprintf(buf, PAGE_SIZE, "0x%lx\n",
-			visorchannel_get_nbytes(dev->visorchannel));
+			visorchannel_get_nbytes(vdev->visorchannel));
 }
 
-static ssize_t devicechannel_attr_clientpartition(struct visor_device *dev,
-						  char *buf) {
-	if (!dev->visorchannel)
+static ssize_t clientpartition_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct visor_device *vdev = to_visor_device(dev);
+
+	if (!vdev->visorchannel)
 		return 0;
 	return snprintf(buf, PAGE_SIZE, "0x%Lx\n",
-			visorchannel_get_clientpartition(dev->visorchannel));
+			visorchannel_get_clientpartition(vdev->visorchannel));
 }
 
-static ssize_t devicechannel_attr_typeguid(struct visor_device *dev, char *buf)
+static ssize_t typeguid_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
 {
+	struct visor_device *vdev = to_visor_device(dev);
 	char s[99];
 
-	if (!dev->visorchannel)
+	if (!vdev->visorchannel)
 		return 0;
 	return snprintf(buf, PAGE_SIZE, "%s\n",
-			visorchannel_id(dev->visorchannel, s));
+			visorchannel_id(vdev->visorchannel, s));
 }
 
-static ssize_t devicechannel_attr_zoneguid(struct visor_device *dev, char *buf)
+static ssize_t zoneguid_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
 {
+	struct visor_device *vdev = to_visor_device(dev);
 	char s[99];
 
-	if (!dev->visorchannel)
+	if (!vdev->visorchannel)
 		return 0;
 	return snprintf(buf, PAGE_SIZE, "%s\n",
-			visorchannel_zoneid(dev->visorchannel, s));
+			visorchannel_zoneid(vdev->visorchannel, s));
 }
 
-static ssize_t devicechannel_attr_typename(struct visor_device *dev, char *buf)
+static ssize_t typename_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
 {
+	struct visor_device *vdev = to_visor_device(dev);
 	int i = 0;
-	struct bus_type *xbus = dev->device.bus;
-	struct device_driver *xdrv = dev->device.driver;
+	struct bus_type *xbus = dev->bus;
+	struct device_driver *xdrv = dev->driver;
 	struct visor_driver *drv = NULL;
 
-	if (!dev->visorchannel || !xbus || !xdrv)
+	if (!vdev->visorchannel || !xbus || !xdrv)
 		return 0;
-	i = xbus->match(&dev->device, xdrv);
+	i = xbus->match(dev, xdrv);
 	if (!i)
 		return 0;
 	drv = to_visor_driver(xdrv);
 	return snprintf(buf, PAGE_SIZE, "%s\n", drv->channel_types[i - 1].name);
 }
 
-static ssize_t devicechannel_attr_dump(struct visor_device *dev, char *buf)
+static ssize_t dump_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
 {
-	int count = 0;
 /* TODO: replace this with debugfs code
+	struct visor_device *vdev = to_visor_device(dev);
+	int count = 0;
 	struct seq_file *m = NULL;
-	if (dev->visorchannel == NULL)
+	if (vdev->visorchannel == NULL)
 		return 0;
 	m = visor_seq_file_new_buffer(buf, PAGE_SIZE - 1);
 	if (m == NULL)
 		return 0;
-	visorchannel_debug(dev->visorchannel, 1, m, 0);
+	visorchannel_debug(vdev->visorchannel, 1, m, 0);
 	count = m->count;
 	visor_seq_file_done_buffer(m);
 	m = NULL;
 */
-	return count;
-}
-
-static struct channel_attribute all_channel_attrs[] = {
-	__ATTR(physaddr, S_IRUGO,
-	       devicechannel_attr_physaddr, NULL),
-	__ATTR(nbytes, S_IRUGO,
-	       devicechannel_attr_nbytes, NULL),
-	__ATTR(clientpartition, S_IRUGO,
-	       devicechannel_attr_clientpartition, NULL),
-	__ATTR(typeguid, S_IRUGO,
-	       devicechannel_attr_typeguid, NULL),
-	__ATTR(zoneguid, S_IRUGO,
-	       devicechannel_attr_zoneguid, NULL),
-	__ATTR(typename, S_IRUGO,
-	       devicechannel_attr_typename, NULL),
-	__ATTR(dump, S_IRUGO,
-	       devicechannel_attr_dump, NULL),
-};
-
-/* end implementation of specific channel attributes */
-
-static ssize_t channel_attr_show(struct kobject *kobj, struct attribute *attr,
-				 char *buf)
-{
-	struct channel_attribute *channel_attr = to_channel_attr(attr);
-	struct visor_device *dev = to_visor_device_from_kobjchannel(kobj);
-	ssize_t ret = 0;
-
-	if (channel_attr->show)
-		ret = channel_attr->show(dev, buf);
-	return ret;
-}
-
-static ssize_t channel_attr_store(struct kobject *kobj, struct attribute *attr,
-				  const char *buf, size_t count)
-{
-	struct channel_attribute *channel_attr = to_channel_attr(attr);
-	struct visor_device *dev = to_visor_device_from_kobjchannel(kobj);
-	ssize_t ret = 0;
-
-	if (channel_attr->store)
-		ret = channel_attr->store(dev, buf, count);
-	return ret;
-}
-
-static int channel_create_file(struct visor_device *dev,
-			       struct channel_attribute *attr)
-{
-	return sysfs_create_file(&dev->kobjchannel, &attr->attr);
-}
-
-static void channel_remove_file(struct visor_device *dev,
-				struct channel_attribute *attr)
-{
-	sysfs_remove_file(&dev->kobjchannel, &attr->attr);
+	return 0;
 }
 
-static const struct sysfs_ops channel_sysfs_ops = {
-	.show = channel_attr_show,
-	.store = channel_attr_store,
+static DEVICE_ATTR_RO(physaddr);
+static DEVICE_ATTR_RO(nbytes);
+static DEVICE_ATTR_RO(clientpartition);
+static DEVICE_ATTR_RO(typeguid);
+static DEVICE_ATTR_RO(zoneguid);
+static DEVICE_ATTR_RO(typename);
+static DEVICE_ATTR_RO(dump);
+
+static struct attribute *channel_attrs[] = {
+		&dev_attr_physaddr.attr,
+		&dev_attr_nbytes.attr,
+		&dev_attr_clientpartition.attr,
+		&dev_attr_typeguid.attr,
+		&dev_attr_zoneguid.attr,
+		&dev_attr_typename.attr,
+		&dev_attr_dump.attr,
 };
 
-static struct kobj_type channel_kobj_type = {
-	.sysfs_ops = &channel_sysfs_ops
+static struct attribute_group channel_attr_grp = {
+		.name = "channel",
+		.attrs = channel_attrs,
 };
 
-int register_channel_attributes(struct visor_device *dev)
-{
-	int rc = 0, i = 0, x = 0;
-
-	if (dev->kobjchannel.parent)
-		goto away;	/* already registered */
-	x = kobject_init_and_add(&dev->kobjchannel, &channel_kobj_type,
-				 &dev->device.kobj, "channel");
-	if (x < 0) {
-		rc = x;
-		goto away;
-	}
-
-	kobject_uevent(&dev->kobjchannel, KOBJ_ADD);
-
-	for (i = 0;
-	     i < sizeof(all_channel_attrs) / sizeof(struct channel_attribute);
-	     i++)
-		x = channel_create_file(dev, &all_channel_attrs[i]);
-	if (x < 0) {
-		while (--i >= 0)
-			channel_remove_file(dev, &all_channel_attrs[i]);
-		kobject_del(&dev->kobjchannel);
-		kobject_put(&dev->kobjchannel);
-		rc = x;
-		goto away;
-	}
-away:
-	return rc;
-}
-
-void unregister_channel_attributes(struct visor_device *dev)
-{
-	int i = 0;
+static const struct attribute_group *visorbus_dev_groups[] = {
+		&channel_attr_grp,
+		NULL
+};
 
-	if (!dev->kobjchannel.parent)
-		return;		/* already unregistered */
-	for (i = 0;
-	     i < sizeof(all_channel_attrs) / sizeof(struct channel_attribute);
-	     i++)
-		channel_remove_file(dev, &all_channel_attrs[i]);
+/* end implementation of specific channel attributes */
 
-	kobject_del(&dev->kobjchannel);
-	kobject_put(&dev->kobjchannel);
-	dev->kobjchannel.parent = NULL;
-}
 #define to_visorbus_devdata(obj) \
 	container_of(obj, struct visorbus_devdata, dev)
 
@@ -1144,6 +1064,7 @@ create_visor_device(struct visorbus_devdata *devdata,
 	dev->device.parent = &devdata->dev;
 	sema_init(&dev->visordriver_callback_lock, 1);	/* unlocked */
 	dev->device.bus = &visorbus_type;
+	dev->device.groups = visorbus_dev_groups;
 	device_initialize(&dev->device);
 	dev->device.release = visorbus_release_device;
 	/* keep a reference just for us (now 2) */
@@ -1191,13 +1112,6 @@ create_visor_device(struct visorbus_devdata *devdata,
 	}
 
 	/* note: device_register is simply device_initialize + device_add */
-	rc = register_channel_attributes(dev);
-	if (rc < 0) {
-		POSTCODE_LINUX_3(DEVICE_REGISTER_FAILURE_PC, chipset_dev_no,
-				 DIAG_SEVERITY_ERR);
-		goto away;
-	}
-
 	registered1 = true;
 
 	rc = register_devmajorminor_attributes(dev);
@@ -1214,8 +1128,6 @@ create_visor_device(struct visorbus_devdata *devdata,
 	if (rc < 0) {
 		if (registered2)
 			unregister_devmajorminor_attributes(dev);
-		if (registered1)
-			unregister_channel_attributes(dev);
 		if (gotten)
 			put_device(&dev->device);
 		if (visorchannel)
@@ -1233,7 +1145,6 @@ remove_visor_device(struct visor_device *dev)
 {
 	list_del(&dev->list_all);
 	unregister_devmajorminor_attributes(dev);
-	unregister_channel_attributes(dev);
 	put_device(&dev->device);
 	device_unregister(&dev->device);
 }