usb-gadget: use per-attribute show and store methods

To simplify the configfs interface and remove boilerplate code that also
causes binary bloat.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 118 insertions, 196 deletions

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 294eb74fb078..163d305e1200 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -64,6 +64,11 @@ struct gadget_info {
         char qw_sign[OS_STRING_QW_SIGN_LEN];
 };
 
+static inline struct gadget_info *to_gadget_info(struct config_item *item)
+{
+         return container_of(to_config_group(item), struct gadget_info, group);
+}
+
 struct config_usb_cfg {
         struct config_group group;
         struct config_group strings_group;
@@ -74,6 +79,12 @@ struct config_usb_cfg {
         struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1];
 };
 
+static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
+{
+        return container_of(to_config_group(item), struct config_usb_cfg,
+                        group);
+}
+
 struct gadget_strings {
         struct usb_gadget_strings stringtab_dev;
         struct usb_string strings[USB_GADGET_FIRST_AVAIL_IDX];
@@ -117,32 +128,25 @@ static int usb_string_copy(const char *s, char **s_copy)
         return 0;
 }
 
-CONFIGFS_ATTR_STRUCT(gadget_info);
-CONFIGFS_ATTR_STRUCT(config_usb_cfg);
-
-#define GI_DEVICE_DESC_ITEM_ATTR(name)  \
-        static struct gadget_info_attribute gadget_cdev_desc_##name = \
-                __CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,               \
-                                gadget_dev_desc_##name##_show,          \
-                                gadget_dev_desc_##name##_store)
-
 #define GI_DEVICE_DESC_SIMPLE_R_u8(__name)      \
-        static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
+static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
                         char *page)     \
 {       \
-        return sprintf(page, "0x%02x\n", gi->cdev.desc.__name); \
+        return sprintf(page, "0x%02x\n", \
+                to_gadget_info(item)->cdev.desc.__name); \
 }
 
 #define GI_DEVICE_DESC_SIMPLE_R_u16(__name)     \
-        static ssize_t gadget_dev_desc_##__name##_show(struct gadget_info *gi, \
+static ssize_t gadget_dev_desc_##__name##_show(struct config_item *item, \
                         char *page)     \
 {       \
-        return sprintf(page, "0x%04x\n", le16_to_cpup(&gi->cdev.desc.__name)); \
+        return sprintf(page, "0x%04x\n", \
+                le16_to_cpup(&to_gadget_info(item)->cdev.desc.__name)); \
 }
 
 
 #define GI_DEVICE_DESC_SIMPLE_W_u8(_name)               \
-        static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
+static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
                 const char *page, size_t len)           \
 {                                                       \
         u8 val;                                         \
@@ -150,12 +154,12 @@ CONFIGFS_ATTR_STRUCT(config_usb_cfg);
         ret = kstrtou8(page, 0, &val);                  \
         if (ret)                                        \
                 return ret;                             \
-        gi->cdev.desc._name = val;                      \
+        to_gadget_info(item)->cdev.desc._name = val;    \
         return len;                                     \
 }
 
 #define GI_DEVICE_DESC_SIMPLE_W_u16(_name)      \
-        static ssize_t gadget_dev_desc_##_name##_store(struct gadget_info *gi, \
+static ssize_t gadget_dev_desc_##_name##_store(struct config_item *item, \
                 const char *page, size_t len)           \
 {                                                       \
         u16 val;                                        \
@@ -163,7 +167,7 @@ CONFIGFS_ATTR_STRUCT(config_usb_cfg);
         ret = kstrtou16(page, 0, &val);                 \
         if (ret)                                        \
                 return ret;                             \
-        gi->cdev.desc._name = cpu_to_le16p(&val);       \
+        to_gadget_info(item)->cdev.desc._name = cpu_to_le16p(&val);     \
         return len;                                     \
 }
 
@@ -193,7 +197,7 @@ static ssize_t is_valid_bcd(u16 bcd_val)
         return 0;
 }
 
-static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi,
+static ssize_t gadget_dev_desc_bcdDevice_store(struct config_item *item,
                 const char *page, size_t len)
 {
         u16 bcdDevice;
@@ -206,11 +210,11 @@ static ssize_t gadget_dev_desc_bcdDevice_store(struct gadget_info *gi,
         if (ret)
                 return ret;
 
-        gi->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
+        to_gadget_info(item)->cdev.desc.bcdDevice = cpu_to_le16(bcdDevice);
         return len;
 }
 
-static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi,
+static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
                 const char *page, size_t len)
 {
         u16 bcdUSB;
@@ -223,13 +227,13 @@ static ssize_t gadget_dev_desc_bcdUSB_store(struct gadget_info *gi,
         if (ret)
                 return ret;
 
-        gi->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
+        to_gadget_info(item)->cdev.desc.bcdUSB = cpu_to_le16(bcdUSB);
         return len;
 }
 
-static ssize_t gadget_dev_desc_UDC_show(struct gadget_info *gi, char *page)
+static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
 {
-        return sprintf(page, "%s\n", gi->udc_name ?: "");
+        return sprintf(page, "%s\n", to_gadget_info(item)->udc_name ?: "");
 }
 
 static int unregister_gadget(struct gadget_info *gi)
@@ -247,9 +251,10 @@ static int unregister_gadget(struct gadget_info *gi)
         return 0;
 }
 
-static ssize_t gadget_dev_desc_UDC_store(struct gadget_info *gi,
+static ssize_t gadget_dev_desc_UDC_store(struct config_item *item,
                 const char *page, size_t len)
 {
+        struct gadget_info *gi = to_gadget_info(item);
         char *name;
         int ret;
 
@@ -283,34 +288,29 @@ err:
         return ret;
 }
 
-GI_DEVICE_DESC_ITEM_ATTR(bDeviceClass);
-GI_DEVICE_DESC_ITEM_ATTR(bDeviceSubClass);
-GI_DEVICE_DESC_ITEM_ATTR(bDeviceProtocol);
-GI_DEVICE_DESC_ITEM_ATTR(bMaxPacketSize0);
-GI_DEVICE_DESC_ITEM_ATTR(idVendor);
-GI_DEVICE_DESC_ITEM_ATTR(idProduct);
-GI_DEVICE_DESC_ITEM_ATTR(bcdDevice);
-GI_DEVICE_DESC_ITEM_ATTR(bcdUSB);
-GI_DEVICE_DESC_ITEM_ATTR(UDC);
+CONFIGFS_ATTR(gadget_dev_desc_, bDeviceClass);
+CONFIGFS_ATTR(gadget_dev_desc_, bDeviceSubClass);
+CONFIGFS_ATTR(gadget_dev_desc_, bDeviceProtocol);
+CONFIGFS_ATTR(gadget_dev_desc_, bMaxPacketSize0);
+CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
+CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
+CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
+CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
+CONFIGFS_ATTR(gadget_dev_desc_, UDC);
 
 static struct configfs_attribute *gadget_root_attrs[] = {
-        &gadget_cdev_desc_bDeviceClass.attr,
-        &gadget_cdev_desc_bDeviceSubClass.attr,
-        &gadget_cdev_desc_bDeviceProtocol.attr,
-        &gadget_cdev_desc_bMaxPacketSize0.attr,
-        &gadget_cdev_desc_idVendor.attr,
-        &gadget_cdev_desc_idProduct.attr,
-        &gadget_cdev_desc_bcdDevice.attr,
-        &gadget_cdev_desc_bcdUSB.attr,
-        &gadget_cdev_desc_UDC.attr,
+        &gadget_dev_desc_attr_bDeviceClass,
+        &gadget_dev_desc_attr_bDeviceSubClass,
+        &gadget_dev_desc_attr_bDeviceProtocol,
+        &gadget_dev_desc_attr_bMaxPacketSize0,
+        &gadget_dev_desc_attr_idVendor,
+        &gadget_dev_desc_attr_idProduct,
+        &gadget_dev_desc_attr_bcdDevice,
+        &gadget_dev_desc_attr_bcdUSB,
+        &gadget_dev_desc_attr_UDC,
         NULL,
 };
 
-static inline struct gadget_info *to_gadget_info(struct config_item *item)
-{
-         return container_of(to_config_group(item), struct gadget_info, group);
-}
-
 static inline struct gadget_strings *to_gadget_strings(struct config_item *item)
 {
          return container_of(to_config_group(item), struct gadget_strings,
@@ -324,12 +324,6 @@ static inline struct gadget_config_name *to_gadget_config_name(
                          group);
 }
 
-static inline struct config_usb_cfg *to_config_usb_cfg(struct config_item *item)
-{
-        return container_of(to_config_group(item), struct config_usb_cfg,
-                        group);
-}
-
 static inline struct usb_function_instance *to_usb_function_instance(
                 struct config_item *item)
 {
@@ -348,12 +342,8 @@ static void gadget_info_attr_release(struct config_item *item)
         kfree(gi);
 }
 
-CONFIGFS_ATTR_OPS(gadget_info);
-
 static struct configfs_item_operations gadget_root_item_ops = {
         .release                = gadget_info_attr_release,
-        .show_attribute         = gadget_info_attr_show,
-        .store_attribute        = gadget_info_attr_store,
 };
 
 static void gadget_config_attr_release(struct config_item *item)
@@ -454,24 +444,20 @@ static int config_usb_cfg_unlink(
         return 0;
 }
 
-CONFIGFS_ATTR_OPS(config_usb_cfg);
-
 static struct configfs_item_operations gadget_config_item_ops = {
         .release                = gadget_config_attr_release,
-        .show_attribute         = config_usb_cfg_attr_show,
-        .store_attribute        = config_usb_cfg_attr_store,
         .allow_link             = config_usb_cfg_link,
         .drop_link              = config_usb_cfg_unlink,
 };
 
 
-static ssize_t gadget_config_desc_MaxPower_show(struct config_usb_cfg *cfg,
+static ssize_t gadget_config_desc_MaxPower_show(struct config_item *item,
                 char *page)
 {
-        return sprintf(page, "%u\n", cfg->c.MaxPower);
+        return sprintf(page, "%u\n", to_config_usb_cfg(item)->c.MaxPower);
 }
 
-static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg,
+static ssize_t gadget_config_desc_MaxPower_store(struct config_item *item,
                 const char *page, size_t len)
 {
         u16 val;
@@ -481,17 +467,18 @@ static ssize_t gadget_config_desc_MaxPower_store(struct config_usb_cfg *cfg,
                 return ret;
         if (DIV_ROUND_UP(val, 8) > 0xff)
                 return -ERANGE;
-        cfg->c.MaxPower = val;
+        to_config_usb_cfg(item)->c.MaxPower = val;
         return len;
 }
 
-static ssize_t gadget_config_desc_bmAttributes_show(struct config_usb_cfg *cfg,
+static ssize_t gadget_config_desc_bmAttributes_show(struct config_item *item,
                 char *page)
 {
-        return sprintf(page, "0x%02x\n", cfg->c.bmAttributes);
+        return sprintf(page, "0x%02x\n",
+                to_config_usb_cfg(item)->c.bmAttributes);
 }
 
-static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg,
+static ssize_t gadget_config_desc_bmAttributes_store(struct config_item *item,
                 const char *page, size_t len)
 {
         u8 val;
@@ -504,22 +491,16 @@ static ssize_t gadget_config_desc_bmAttributes_store(struct config_usb_cfg *cfg,
         if (val & ~(USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER |
                                 USB_CONFIG_ATT_WAKEUP))
                 return -EINVAL;
-        cfg->c.bmAttributes = val;
+        to_config_usb_cfg(item)->c.bmAttributes = val;
         return len;
 }
 
-#define CFG_CONFIG_DESC_ITEM_ATTR(name) \
-        static struct config_usb_cfg_attribute gadget_usb_cfg_##name = \
-                __CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,               \
-                                gadget_config_desc_##name##_show,       \
-                                gadget_config_desc_##name##_store)
-
-CFG_CONFIG_DESC_ITEM_ATTR(MaxPower);
-CFG_CONFIG_DESC_ITEM_ATTR(bmAttributes);
+CONFIGFS_ATTR(gadget_config_desc_, MaxPower);
+CONFIGFS_ATTR(gadget_config_desc_, bmAttributes);
 
 static struct configfs_attribute *gadget_config_attrs[] = {
-        &gadget_usb_cfg_MaxPower.attr,
-        &gadget_usb_cfg_bmAttributes.attr,
+        &gadget_config_desc_attr_MaxPower,
+        &gadget_config_desc_attr_bmAttributes,
         NULL,
 };
 
@@ -616,11 +597,10 @@ static struct config_item_type functions_type = {
         .ct_owner       = THIS_MODULE,
 };
 
-CONFIGFS_ATTR_STRUCT(gadget_config_name);
 GS_STRINGS_RW(gadget_config_name, configuration);
 
 static struct configfs_attribute *gadget_config_name_langid_attrs[] = {
-        &gadget_config_name_configuration.attr,
+        &gadget_config_name_attr_configuration,
         NULL,
 };
 
@@ -719,15 +699,14 @@ static struct config_item_type config_desc_type = {
         .ct_owner       = THIS_MODULE,
 };
 
-CONFIGFS_ATTR_STRUCT(gadget_strings);
 GS_STRINGS_RW(gadget_strings, manufacturer);
 GS_STRINGS_RW(gadget_strings, product);
 GS_STRINGS_RW(gadget_strings, serialnumber);
 
 static struct configfs_attribute *gadget_strings_langid_attrs[] = {
-        &gadget_strings_manufacturer.attr,
-        &gadget_strings_product.attr,
-        &gadget_strings_serialnumber.attr,
+        &gadget_strings_attr_manufacturer,
+        &gadget_strings_attr_product,
+        &gadget_strings_attr_serialnumber,
         NULL,
 };
 
@@ -751,27 +730,25 @@ static inline struct os_desc *to_os_desc(struct config_item *item)
         return container_of(to_config_group(item), struct os_desc, group);
 }
 
-CONFIGFS_ATTR_STRUCT(os_desc);
-CONFIGFS_ATTR_OPS(os_desc);
-
-static ssize_t os_desc_use_show(struct os_desc *os_desc, char *page)
+static inline struct gadget_info *os_desc_item_to_gadget_info(
+                struct config_item *item)
 {
-        struct gadget_info *gi;
-
-        gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
+        return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent);
+}
 
-        return sprintf(page, "%d", gi->use_os_desc);
+static ssize_t os_desc_use_show(struct config_item *item, char *page)
+{
+        return sprintf(page, "%d",
+                        os_desc_item_to_gadget_info(item)->use_os_desc);
 }
 
-static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page,
+static ssize_t os_desc_use_store(struct config_item *item, const char *page,
                                  size_t len)
 {
-        struct gadget_info *gi;
+        struct gadget_info *gi = os_desc_item_to_gadget_info(item);
         int ret;
         bool use;
 
-        gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
-
         mutex_lock(&gi->lock);
         ret = strtobool(page, &use);
         if (!ret) {
@@ -783,29 +760,19 @@ static ssize_t os_desc_use_store(struct os_desc *os_desc, const char *page,
         return ret;
 }
 
-static struct os_desc_attribute os_desc_use =
-        __CONFIGFS_ATTR(use, S_IRUGO | S_IWUSR,
-                        os_desc_use_show,
-                        os_desc_use_store);
-
-static ssize_t os_desc_b_vendor_code_show(struct os_desc *os_desc, char *page)
+static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
 {
-        struct gadget_info *gi;
-
-        gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
-
-        return sprintf(page, "%d", gi->b_vendor_code);
+        return sprintf(page, "%d",
+                        os_desc_item_to_gadget_info(item)->b_vendor_code);
 }
 
-static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc,
+static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
                                            const char *page, size_t len)
 {
-        struct gadget_info *gi;
+        struct gadget_info *gi = os_desc_item_to_gadget_info(item);
         int ret;
         u8 b_vendor_code;
 
-        gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
-
         mutex_lock(&gi->lock);
         ret = kstrtou8(page, 0, &b_vendor_code);
         if (!ret) {
@@ -817,29 +784,20 @@ static ssize_t os_desc_b_vendor_code_store(struct os_desc *os_desc,
         return ret;
 }
 
-static struct os_desc_attribute os_desc_b_vendor_code =
-        __CONFIGFS_ATTR(b_vendor_code, S_IRUGO | S_IWUSR,
-                        os_desc_b_vendor_code_show,
-                        os_desc_b_vendor_code_store);
-
-static ssize_t os_desc_qw_sign_show(struct os_desc *os_desc, char *page)
+static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
 {
-        struct gadget_info *gi;
-
-        gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
+        struct gadget_info *gi = os_desc_item_to_gadget_info(item);
 
         memcpy(page, gi->qw_sign, OS_STRING_QW_SIGN_LEN);
-
         return OS_STRING_QW_SIGN_LEN;
 }
 
-static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page,
+static ssize_t os_desc_qw_sign_store(struct config_item *item, const char *page,
                                      size_t len)
 {
-        struct gadget_info *gi;
+        struct gadget_info *gi = os_desc_item_to_gadget_info(item);
         int res, l;
 
-        gi = to_gadget_info(os_desc->group.cg_item.ci_parent);
         l = min((int)len, OS_STRING_QW_SIGN_LEN >> 1);
         if (page[l - 1] == '\n')
                 --l;
@@ -855,15 +813,14 @@ static ssize_t os_desc_qw_sign_store(struct os_desc *os_desc, const char *page,
         return res;
 }
 
-static struct os_desc_attribute os_desc_qw_sign =
-        __CONFIGFS_ATTR(qw_sign, S_IRUGO | S_IWUSR,
-                        os_desc_qw_sign_show,
-                        os_desc_qw_sign_store);
+CONFIGFS_ATTR(os_desc_, use);
+CONFIGFS_ATTR(os_desc_, b_vendor_code);
+CONFIGFS_ATTR(os_desc_, qw_sign);
 
 static struct configfs_attribute *os_desc_attrs[] = {
-        &os_desc_use.attr,
-        &os_desc_b_vendor_code.attr,
-        &os_desc_qw_sign.attr,
+        &os_desc_attr_use,
+        &os_desc_attr_b_vendor_code,
+        &os_desc_attr_qw_sign,
         NULL,
 };
 
@@ -926,8 +883,6 @@ static int os_desc_unlink(struct config_item *os_desc_ci,
 
 static struct configfs_item_operations os_desc_ops = {
         .release                = os_desc_attr_release,
-        .show_attribute         = os_desc_attr_show,
-        .store_attribute        = os_desc_attr_store,
         .allow_link             = os_desc_link,
         .drop_link              = os_desc_unlink,
 };
@@ -938,28 +893,21 @@ static struct config_item_type os_desc_type = {
         .ct_owner       = THIS_MODULE,
 };
 
-CONFIGFS_ATTR_STRUCT(usb_os_desc);
-CONFIGFS_ATTR_OPS(usb_os_desc);
-
-
 static inline struct usb_os_desc_ext_prop
 *to_usb_os_desc_ext_prop(struct config_item *item)
 {
         return container_of(item, struct usb_os_desc_ext_prop, item);
 }
 
-CONFIGFS_ATTR_STRUCT(usb_os_desc_ext_prop);
-CONFIGFS_ATTR_OPS(usb_os_desc_ext_prop);
-
-static ssize_t ext_prop_type_show(struct usb_os_desc_ext_prop *ext_prop,
-                                  char *page)
+static ssize_t ext_prop_type_show(struct config_item *item, char *page)
 {
-        return sprintf(page, "%d", ext_prop->type);
+        return sprintf(page, "%d", to_usb_os_desc_ext_prop(item)->type);
 }
 
-static ssize_t ext_prop_type_store(struct usb_os_desc_ext_prop *ext_prop,
+static ssize_t ext_prop_type_store(struct config_item *item,
                                    const char *page, size_t len)
 {
+        struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
         struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
         u8 type;
         int ret;
@@ -997,9 +945,9 @@ end:
         return ret;
 }
 
-static ssize_t ext_prop_data_show(struct usb_os_desc_ext_prop *ext_prop,
-                                  char *page)
+static ssize_t ext_prop_data_show(struct config_item *item, char *page)
 {
+        struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
         int len = ext_prop->data_len;
 
         if (ext_prop->type == USB_EXT_PROP_UNICODE ||
@@ -1011,9 +959,10 @@ static ssize_t ext_prop_data_show(struct usb_os_desc_ext_prop *ext_prop,
         return len;
 }
 
-static ssize_t ext_prop_data_store(struct usb_os_desc_ext_prop *ext_prop,
+static ssize_t ext_prop_data_store(struct config_item *item,
                                    const char *page, size_t len)
 {
+        struct usb_os_desc_ext_prop *ext_prop = to_usb_os_desc_ext_prop(item);
         struct usb_os_desc *desc = to_usb_os_desc(ext_prop->item.ci_parent);
         char *new_data;
         size_t ret_len = len;
@@ -1044,17 +993,12 @@ static ssize_t ext_prop_data_store(struct usb_os_desc_ext_prop *ext_prop,
         return ret_len;
 }
 
-static struct usb_os_desc_ext_prop_attribute ext_prop_type =
-        __CONFIGFS_ATTR(type, S_IRUGO | S_IWUSR,
-                        ext_prop_type_show, ext_prop_type_store);
-
-static struct usb_os_desc_ext_prop_attribute ext_prop_data =
-        __CONFIGFS_ATTR(data, S_IRUGO | S_IWUSR,
-                        ext_prop_data_show, ext_prop_data_store);
+CONFIGFS_ATTR(ext_prop_, type);
+CONFIGFS_ATTR(ext_prop_, data);
 
 static struct configfs_attribute *ext_prop_attrs[] = {
-        &ext_prop_type.attr,
-        &ext_prop_data.attr,
+        &ext_prop_attr_type,
+        &ext_prop_attr_data,
         NULL,
 };
 
@@ -1067,8 +1011,6 @@ static void usb_os_desc_ext_prop_release(struct config_item *item)
 
 static struct configfs_item_operations ext_prop_ops = {
         .release                = usb_os_desc_ext_prop_release,
-        .show_attribute         = usb_os_desc_ext_prop_attr_show,
-        .store_attribute        = usb_os_desc_ext_prop_attr_store,
 };
 
 static struct config_item *ext_prop_make(
@@ -1137,21 +1079,17 @@ static struct configfs_group_operations interf_grp_ops = {
         .drop_item      = &ext_prop_drop,
 };
 
-static struct configfs_item_operations interf_item_ops = {
-        .show_attribute         = usb_os_desc_attr_show,
-        .store_attribute        = usb_os_desc_attr_store,
-};
-
-static ssize_t interf_grp_compatible_id_show(struct usb_os_desc *desc,
+static ssize_t interf_grp_compatible_id_show(struct config_item *item,
                                              char *page)
 {
-        memcpy(page, desc->ext_compat_id, 8);
+        memcpy(page, to_usb_os_desc(item)->ext_compat_id, 8);
         return 8;
 }
 
-static ssize_t interf_grp_compatible_id_store(struct usb_os_desc *desc,
+static ssize_t interf_grp_compatible_id_store(struct config_item *item,
                                               const char *page, size_t len)
 {
+        struct usb_os_desc *desc = to_usb_os_desc(item);
         int l;
 
         l = min_t(int, 8, len);
@@ -1167,21 +1105,17 @@ static ssize_t interf_grp_compatible_id_store(struct usb_os_desc *desc,
         return len;
 }
 
-static struct usb_os_desc_attribute interf_grp_attr_compatible_id =
-        __CONFIGFS_ATTR(compatible_id, S_IRUGO | S_IWUSR,
-                        interf_grp_compatible_id_show,
-                        interf_grp_compatible_id_store);
-
-static ssize_t interf_grp_sub_compatible_id_show(struct usb_os_desc *desc,
+static ssize_t interf_grp_sub_compatible_id_show(struct config_item *item,
                                                  char *page)
 {
-        memcpy(page, desc->ext_compat_id + 8, 8);
+        memcpy(page, to_usb_os_desc(item)->ext_compat_id + 8, 8);
         return 8;
 }
 
-static ssize_t interf_grp_sub_compatible_id_store(struct usb_os_desc *desc,
+static ssize_t interf_grp_sub_compatible_id_store(struct config_item *item,
                                                   const char *page, size_t len)
 {
+        struct usb_os_desc *desc = to_usb_os_desc(item);
         int l;
 
         l = min_t(int, 8, len);
@@ -1197,14 +1131,12 @@ static ssize_t interf_grp_sub_compatible_id_store(struct usb_os_desc *desc,
         return len;
 }
 
-static struct usb_os_desc_attribute interf_grp_attr_sub_compatible_id =
-        __CONFIGFS_ATTR(sub_compatible_id, S_IRUGO | S_IWUSR,
-                        interf_grp_sub_compatible_id_show,
-                        interf_grp_sub_compatible_id_store);
+CONFIGFS_ATTR(interf_grp_, compatible_id);
+CONFIGFS_ATTR(interf_grp_, sub_compatible_id);
 
 static struct configfs_attribute *interf_grp_attrs[] = {
-        &interf_grp_attr_compatible_id.attr,
-        &interf_grp_attr_sub_compatible_id.attr,
+        &interf_grp_attr_compatible_id,
+        &interf_grp_attr_sub_compatible_id,
         NULL
 };
 
@@ -1242,7 +1174,6 @@ int usb_os_desc_prepare_interf_dir(struct config_group *parent,
         f_default_groups[0] = os_desc_group;
 
         os_desc_group->default_groups = interface_groups;
-        interface_type->ct_item_ops = &interf_item_ops;
         interface_type->ct_group_ops = &interf_grp_ops;
         interface_type->ct_attrs = interf_grp_attrs;
         interface_type->ct_owner = owner;
diff --git a/include/linux/usb/gadget_configfs.h b/include/linux/usb/gadget_configfs.h
index d74c0ae989d5..c36e95730de1 100644
--- a/include/linux/usb/gadget_configfs.h
+++ b/include/linux/usb/gadget_configfs.h
@@ -7,9 +7,10 @@ int check_user_usb_string(const char *name,
                 struct usb_gadget_strings *stringtab_dev);
 
 #define GS_STRINGS_W(__struct, __name)  \
-        static ssize_t __struct##_##__name##_store(struct __struct *gs, \
+static ssize_t __struct##_##__name##_store(struct config_item *item, \
                 const char *page, size_t len)           \
 {                                                       \
+        struct __struct *gs = to_##__struct(item);      \
         int ret;                                        \
                                                         \
         ret = usb_string_copy(page, &gs->__name);       \
@@ -19,30 +20,20 @@ int check_user_usb_string(const char *name,
 }
 
 #define GS_STRINGS_R(__struct, __name)  \
-        static ssize_t __struct##_##__name##_show(struct __struct *gs, \
-                        char *page)     \
+static ssize_t __struct##_##__name##_show(struct config_item *item, char *page) \
 {       \
+        struct __struct *gs = to_##__struct(item);      \
         return sprintf(page, "%s\n", gs->__name ?: ""); \
 }
 
-#define GS_STRING_ITEM_ATTR(struct_name, name)  \
-        static struct struct_name##_attribute struct_name##_##name = \
-                __CONFIGFS_ATTR(name,  S_IRUGO | S_IWUSR,               \
-                                struct_name##_##name##_show,            \
-                                struct_name##_##name##_store)
-
 #define GS_STRINGS_RW(struct_name, _name)       \
         GS_STRINGS_R(struct_name, _name)        \
         GS_STRINGS_W(struct_name, _name)        \
-        GS_STRING_ITEM_ATTR(struct_name, _name)
+        CONFIGFS_ATTR(struct_name##_, _name)
 
 #define USB_CONFIG_STRING_RW_OPS(struct_in)                             \
-        CONFIGFS_ATTR_OPS(struct_in);                                   \
-                                                                        \
 static struct configfs_item_operations struct_in##_langid_item_ops = {  \
         .release                = struct_in##_attr_release,             \
-        .show_attribute         = struct_in##_attr_show,                \
-        .store_attribute        = struct_in##_attr_store,               \
 };                                                                      \
                                                                         \
 static struct config_item_type struct_in##_langid_type = {              \