[PATCH v5 16/23] usb: gadget: g_ffs: allocate and init otg descriptor by otg capabilities

[Li Jun <jun.li-KZfg59tc24xl57MIdRCFDg@public.gmane.org>]

Allocate and initialize usb otg descriptor according to gadget otg
capabilities, add it for each usb configurations. If otg capability
is not defined, keep its original otg descriptor unchanged.

Signed-off-by: Li Jun <jun.li-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
---
 drivers/usb/gadget/legacy/g_ffs.c | 42 ++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/drivers/usb/gadget/legacy/g_ffs.c b/drivers/usb/gadget/legacy/g_ffs.c
index 7b9ef7e..a52d5b5 100644
--- a/drivers/usb/gadget/legacy/g_ffs.c
+++ b/drivers/usb/gadget/legacy/g_ffs.c
@@ -88,21 +88,7 @@ MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
 module_param_array_named(functions, func_names, charp, &func_num, 0);
 MODULE_PARM_DESC(functions, "USB Functions list");
 
-static const struct usb_descriptor_header *gfs_otg_desc[] = {
-	(const struct usb_descriptor_header *)
-	&(const struct usb_otg_descriptor) {
-		.bLength		= sizeof(struct usb_otg_descriptor),
-		.bDescriptorType	= USB_DT_OTG,
-
-		/*
-		 * REVISIT SRP-only hardware is possible, although
-		 * it would not be called "OTG" ...
-		 */
-		.bmAttributes		= USB_OTG_SRP | USB_OTG_HNP,
-	},
-
-	NULL
-};
+static const struct usb_descriptor_header *gfs_otg_desc[2];
 
 /* String IDs are assigned dynamically */
 static struct usb_string gfs_strings[] = {
@@ -410,6 +396,17 @@ static int gfs_bind(struct usb_composite_dev *cdev)
 		goto error_rndis;
 	gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id;
 
+	if (gadget_is_otg(cdev->gadget) && !gfs_otg_desc[0]) {
+		struct usb_descriptor_header *usb_desc;
+
+		usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
+		if (!usb_desc)
+			goto error_rndis;
+		usb_otg_descriptor_init(cdev->gadget, usb_desc);
+		gfs_otg_desc[0] = usb_desc;
+		gfs_otg_desc[1] = NULL;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
 		struct gfs_configuration *c = gfs_configurations + i;
 		int sid = USB_GADGET_FIRST_AVAIL_IDX + i;
@@ -419,6 +416,11 @@ static int gfs_bind(struct usb_composite_dev *cdev)
 		c->c.bConfigurationValue	= 1 + i;
 		c->c.bmAttributes		= USB_CONFIG_ATT_SELFPOWER;
 
+		if (gadget_is_otg(cdev->gadget)) {
+			c->c.descriptors = gfs_otg_desc;
+			c->c.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+		}
+
 		c->num = i;
 
 		ret = usb_add_config(cdev, &c->c, gfs_do_config);
@@ -430,6 +432,8 @@ static int gfs_bind(struct usb_composite_dev *cdev)
 
 /* TODO */
 error_unbind:
+	kfree(gfs_otg_desc[0]);
+	gfs_otg_desc[0] = NULL;
 error_rndis:
 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 	usb_put_function_instance(fi_rndis);
@@ -471,6 +475,9 @@ static int gfs_unbind(struct usb_composite_dev *cdev)
 	for (i = 0; i < N_CONF * func_num; ++i)
 		usb_put_function(*(f_ffs[0] + i));
 
+	kfree(gfs_otg_desc[0]);
+	gfs_otg_desc[0] = NULL;
+
 	return 0;
 }
 
@@ -488,11 +495,6 @@ static int gfs_do_config(struct usb_configuration *c)
 	if (missing_funcs)
 		return -ENODEV;
 
-	if (gadget_is_otg(c->cdev->gadget)) {
-		c->descriptors = gfs_otg_desc;
-		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
-	}