usb: gadget: mass_storage: convert to new interface of f_mass_storage

Convert old mass_storage gadget to use the new interface of f_mass_storage
so that later the compatibility layer in f_mass_storage can be removed.

struct fsg_common is not known to mass_storage.c, so a setter method
is added to f_mass_storage.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/Kconfig

@@ -885,6 +885,7 @@ config USB_MASS_STORAGE
 	depends on BLOCK
 	select USB_LIBCOMPOSITE
 	select USB_U_MS
+	select USB_F_MASS_STORAGE
 	help
 	  The Mass Storage Gadget acts as a USB Mass Storage disk drive.
 	  As its storage repository it can use a regular file or a block

drivers/usb/gadget/f_mass_storage.c

@@ -2827,6 +2827,13 @@ int fsg_common_set_nluns(struct fsg_common *common, int nluns)
 }
 EXPORT_SYMBOL_GPL_IF_MODULE(fsg_common_set_nluns);
 
+void fsg_common_set_ops(struct fsg_common *common,
+			const struct fsg_operations *ops)
+{
+	common->ops = ops;
+}
+EXPORT_SYMBOL_GPL_IF_MODULE(fsg_common_set_ops);
+
 void fsg_common_free_buffers(struct fsg_common *common)
 {
 	_fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);

drivers/usb/gadget/f_mass_storage.h

@@ -132,6 +132,9 @@ void fsg_common_free_luns(struct fsg_common *common);
 
 int fsg_common_set_nluns(struct fsg_common *common, int nluns);
 
+void fsg_common_set_ops(struct fsg_common *common,
+			const struct fsg_operations *ops);
+
 int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
 			  unsigned int id, const char *name,
 			  const char **name_pfx);

drivers/usb/gadget/mass_storage.c

@@ -46,17 +46,7 @@
 #define FSG_VENDOR_ID	0x0525	/* NetChip */
 #define FSG_PRODUCT_ID	0xa4a5	/* Linux-USB File-backed Storage Gadget */
 
-/*-------------------------------------------------------------------------*/
+#include "f_mass_storage.h"
-
-/*
- * kbuild is not very cooperative with respect to linking separately
- * compiled library objects into one module.  So for now we won't use
- * separate compilation ... ensuring init/exit sections work to shrink
- * the runtime footprint, and giving us at least some parts of what
- * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
- */
-#define USB_FMS_INCLUDED
-#include "f_mass_storage.c"
 
 /*-------------------------------------------------------------------------*/
 USB_GADGET_COMPOSITE_OPTIONS();
@@ -107,6 +97,9 @@ static struct usb_gadget_strings *dev_strings[] = {
 	NULL,
 };
 
+static struct usb_function_instance *fi_msg;
+static struct usb_function *f_msg;
+
 /****************************** Configurations ******************************/
 
 static struct fsg_module_parameters mod_data = {
@@ -139,13 +132,7 @@ static int msg_thread_exits(struct fsg_common *common)
 
 static int __init msg_do_config(struct usb_configuration *c)
 {
-	static const struct fsg_operations ops = {
+	struct fsg_opts *opts;
-		.thread_exits = msg_thread_exits,
-	};
-	static struct fsg_common common;
-
-	struct fsg_common *retp;
-	struct fsg_config config;
 	int ret;
 
 	if (gadget_is_otg(c->cdev->gadget)) {
@@ -153,15 +140,24 @@ static int __init msg_do_config(struct usb_configuration *c)
 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 	}
 
-	fsg_config_from_params(&config, &mod_data, fsg_num_buffers);
+	opts = fsg_opts_from_func_inst(fi_msg);
-	config.ops = &ops;
 
-	retp = fsg_common_init(&common, c->cdev, &config);
+	f_msg = usb_get_function(fi_msg);
-	if (IS_ERR(retp))
+	if (IS_ERR(f_msg))
-		return PTR_ERR(retp);
+		return PTR_ERR(f_msg);
 
-	ret = fsg_bind_config(c->cdev, c, &common);
+	ret = fsg_common_run_thread(opts->common);
-	fsg_common_put(&common);
+	if (ret)
+		goto put_func;
+
+	ret = usb_add_function(c, f_msg);
+	if (ret)
+		goto put_func;
+
+	return 0;
+
+put_func:
+	usb_put_function(f_msg);
 	return ret;
 }
 
@@ -176,23 +172,79 @@ static struct usb_configuration msg_config_driver = {
 
 static int __init msg_bind(struct usb_composite_dev *cdev)
 {
+	static const struct fsg_operations ops = {
+		.thread_exits = msg_thread_exits,
+	};
+	struct fsg_opts *opts;
+	struct fsg_config config;
 	int status;
 
+	fi_msg = usb_get_function_instance("mass_storage");
+	if (IS_ERR(fi_msg))
+		return PTR_ERR(fi_msg);
+
+	fsg_config_from_params(&config, &mod_data, fsg_num_buffers);
+	opts = fsg_opts_from_func_inst(fi_msg);
+
+	opts->no_configfs = true;
+	status = fsg_common_set_num_buffers(opts->common, fsg_num_buffers);
+	if (status)
+		goto fail;
+
+	status = fsg_common_set_nluns(opts->common, config.nluns);
+	if (status)
+		goto fail_set_nluns;
+
+	fsg_common_set_ops(opts->common, &ops);
+
+	status = fsg_common_set_cdev(opts->common, cdev, config.can_stall);
+	if (status)
+		goto fail_set_cdev;
+
+	fsg_common_set_sysfs(opts->common, true);
+	status = fsg_common_create_luns(opts->common, &config);
+	if (status)
+		goto fail_set_cdev;
+
+	fsg_common_set_inquiry_string(opts->common, config.vendor_name,
+				      config.product_name);
+
 	status = usb_string_ids_tab(cdev, strings_dev);
 	if (status < 0)
-		return status;
+		goto fail_string_ids;
 	msg_device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 
 	status = usb_add_config(cdev, &msg_config_driver, msg_do_config);
 	if (status < 0)
-		return status;
+		goto fail_string_ids;
+
 	usb_composite_overwrite_options(cdev, &coverwrite);
 	dev_info(&cdev->gadget->dev,
 		 DRIVER_DESC ", version: " DRIVER_VERSION "\n");
 	set_bit(0, &msg_registered);
 	return 0;
+
+fail_string_ids:
+	fsg_common_remove_luns(opts->common);
+fail_set_cdev:
+	fsg_common_free_luns(opts->common);
+fail_set_nluns:
+	fsg_common_free_buffers(opts->common);
+fail:
+	usb_put_function_instance(fi_msg);
+	return status;
 }
 
+static int msg_unbind(struct usb_composite_dev *cdev)
+{
+	if (!IS_ERR(f_msg))
+		usb_put_function(f_msg);
+
+	if (!IS_ERR(fi_msg))
+		usb_put_function_instance(fi_msg);
+
+	return 0;
+}
 
 /****************************** Some noise ******************************/
 
@@ -203,6 +255,7 @@ static __refdata struct usb_composite_driver msg_driver = {
 	.needs_serial	= 1,
 	.strings	= dev_strings,
 	.bind		= msg_bind,
+	.unbind		= msg_unbind,
 };
 
 MODULE_DESCRIPTION(DRIVER_DESC);