usb: gadget: tcm: convert to use new function registration interface

Convert the only user of old tcm function interface so that the old
interface can be removed.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/usb/gadget/legacy/Kconfig

@@ -250,6 +250,7 @@ config USB_GADGET_TARGET
 	tristate "USB Gadget Target Fabric Module"
 	depends on TARGET_CORE
 	select USB_LIBCOMPOSITE
+	select USB_F_TCM
 	help
 	  This fabric is an USB gadget. Two USB protocols are supported that is
 	  BBB or BOT (Bulk Only Transport) and UAS (USB Attached SCSI). BOT is

drivers/usb/gadget/legacy/tcm_usb_gadget.c

@@ -21,11 +21,9 @@
 #include <target/target_core_fabric.h>
 #include <asm/unaligned.h>
 
-USB_GADGET_COMPOSITE_OPTIONS();
+#include "u_tcm.h"
 
-/* #include to be removed when new function registration interface is used  */
-#define USBF_TCM_INCLUDED
-#include "../function/f_tcm.c"
+USB_GADGET_COMPOSITE_OPTIONS();
 
 #define UAS_VENDOR_ID	0x0525	/* NetChip */
 #define UAS_PRODUCT_ID	0xa4a5	/* Linux-USB File-backed Storage Gadget */
@@ -60,8 +58,31 @@ static struct usb_gadget_strings *usbg_strings[] = {
 	NULL,
 };
 
+static struct usb_function_instance *fi_tcm;
+static struct usb_function *f_tcm;
+
 static int guas_unbind(struct usb_composite_dev *cdev)
 {
+	if (!IS_ERR_OR_NULL(f_tcm))
+		usb_put_function(f_tcm);
+
+	return 0;
+}
+
+static int tcm_do_config(struct usb_configuration *c)
+{
+	int status;
+
+	f_tcm = usb_get_function(fi_tcm);
+	if (IS_ERR(f_tcm))
+		return PTR_ERR(f_tcm);
+
+	status = usb_add_function(c, f_tcm);
+	if (status < 0) {
+		usb_put_function(f_tcm);
+		return status;
+	}
+
 	return 0;
 }
 
@@ -71,6 +92,9 @@ static struct usb_configuration usbg_config_driver = {
 	.bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 };
 
+static int usbg_attach(struct usb_function_instance *f);
+static void usbg_detach(struct usb_function_instance *f);
+
 static int usb_target_bind(struct usb_composite_dev *cdev)
 {
 	int ret;
@@ -87,8 +111,7 @@ static int usb_target_bind(struct usb_composite_dev *cdev)
 	usbg_config_driver.iConfiguration =
 		usbg_us_strings[USB_G_STR_CONFIG].id;
 
-	ret = usb_add_config(cdev, &usbg_config_driver,
-			tcm_bind_config);
+	ret = usb_add_config(cdev, &usbg_config_driver, tcm_do_config);
 	if (ret)
 		return ret;
 	usb_composite_overwrite_options(cdev, &coverwrite);
@@ -104,25 +127,44 @@ static struct usb_composite_driver usbg_driver = {
 	.unbind         = guas_unbind,
 };
 
-static int usbg_attach(struct usbg_tpg *tpg)
+static int usbg_attach(struct usb_function_instance *f)
 {
 	return usb_composite_probe(&usbg_driver);
 }
 
-static void usbg_detach(struct usbg_tpg *tpg)
+static void usbg_detach(struct usb_function_instance *f)
 {
 	usb_composite_unregister(&usbg_driver);
 }
 
 static int __init usb_target_gadget_init(void)
 {
-	return target_register_template(&usbg_ops);
+	struct f_tcm_opts *tcm_opts;
+
+	fi_tcm = usb_get_function_instance("tcm");
+	if (IS_ERR(fi_tcm))
+		return PTR_ERR(fi_tcm);
+
+	tcm_opts = container_of(fi_tcm, struct f_tcm_opts, func_inst);
+	mutex_lock(&tcm_opts->dep_lock);
+	tcm_opts->tcm_register_callback = usbg_attach;
+	tcm_opts->tcm_unregister_callback = usbg_detach;
+	tcm_opts->dependent = THIS_MODULE;
+	tcm_opts->can_attach = true;
+	tcm_opts->has_dep = true;
+	mutex_unlock(&tcm_opts->dep_lock);
+
+	fi_tcm->set_inst_name(fi_tcm, "tcm-legacy");
+
+	return 0;
 }
 module_init(usb_target_gadget_init);
 
 static void __exit usb_target_gadget_exit(void)
 {
-	target_unregister_template(&usbg_ops);
+	if (!IS_ERR_OR_NULL(fi_tcm))
+		usb_put_function_instance(fi_tcm);
+
 }
 module_exit(usb_target_gadget_exit);