[PATCH v2 1/2] usb: gadget: mass_storage: add SuperSpeed descriptor support

[Thinh Nguyen]

From: Dan Tran <trandan at synopsys.com>

Add SS bulk endpoint descriptors (1024-byte MPS, bMaxBurst=15) to
storage_common.c to support SuperSpeed connections. Extend fsg_ep_desc()
to select them when operating at SuperSpeed, and wire up ss_descriptors
in fsg_bind(). Free ss_descriptors in fsg_unbind() to match.

Signed-off-by: Dan Tran <trandan at synopsys.com>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen at synopsys.com>
---
 Changes in v2:
 - Removed internal Reviewed-by tags


 drivers/usb/gadget/f_mass_storage.c | 25 ++++++++++++--
 drivers/usb/gadget/storage_common.c | 52 ++++++++++++++++++++++++++++-
 2 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 87ed25e8bb3a..a2f34c100482 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -2225,14 +2225,16 @@ reset:
 
 	/* Enable the endpoints */
 	d = fsg_ep_desc(common->gadget,
-			&fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
+			&fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc,
+			&fsg_ss_bulk_in_desc);
 	rc = enable_endpoint(common, fsg->bulk_in, d);
 	if (rc)
 		goto reset;
 	fsg->bulk_in_enabled = 1;
 
 	d = fsg_ep_desc(common->gadget,
-			&fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
+			&fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc,
+			&fsg_ss_bulk_out_desc);
 	rc = enable_endpoint(common, fsg->bulk_out, d);
 	if (rc)
 		goto reset;
@@ -2653,6 +2655,7 @@ static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
 	fsg_common_release(fsg->common);
 	free(fsg->function.descriptors);
 	free(fsg->function.hs_descriptors);
+	free(fsg->function.ss_descriptors);
 	kfree(fsg);
 }
 
@@ -2701,6 +2704,24 @@ static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
 			return -ENOMEM;
 		}
 	}
+
+	if (gadget_is_superspeed(gadget)) {
+		unsigned int max_burst = min_t(unsigned int, FSG_BUFLEN / 1024, 15);
+
+		fsg_ss_bulk_in_desc.bEndpointAddress =
+			fsg_fs_bulk_in_desc.bEndpointAddress;
+		fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
+		fsg_ss_bulk_out_desc.bEndpointAddress =
+			fsg_fs_bulk_out_desc.bEndpointAddress;
+		fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
+		f->ss_descriptors = usb_copy_descriptors(fsg_ss_function);
+		if (unlikely(!f->ss_descriptors)) {
+			free(f->hs_descriptors);
+			free(f->descriptors);
+			return -ENOMEM;
+		}
+	}
+
 	return 0;
 
 autoconf_fail:
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
index 7e4b542f7ce5..d745649eadb7 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/drivers/usb/gadget/storage_common.c
@@ -531,11 +531,61 @@ static struct usb_descriptor_header *fsg_hs_function[] = {
 	NULL,
 };
 
+/*
+ * USB 3.0 requires SuperSpeed descriptors
+ */
+static struct usb_endpoint_descriptor
+fsg_ss_bulk_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
+	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+	/* bMaxBurst set during fsg_bind() */
+};
+
+static struct usb_endpoint_descriptor
+fsg_ss_bulk_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
+	.bLength =		sizeof(fsg_ss_bulk_out_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+	/* bMaxBurst set during fsg_bind() */
+};
+
+static struct usb_descriptor_header *fsg_ss_function[] = {
+#ifndef FSG_NO_OTG
+	(struct usb_descriptor_header *)&fsg_otg_desc,
+#endif
+	(struct usb_descriptor_header *)&fsg_intf_desc,
+	(struct usb_descriptor_header *)&fsg_ss_bulk_in_desc,
+	(struct usb_descriptor_header *)&fsg_ss_bulk_in_comp_desc,
+	(struct usb_descriptor_header *)&fsg_ss_bulk_out_desc,
+	(struct usb_descriptor_header *)&fsg_ss_bulk_out_comp_desc,
+	NULL,
+};
+
 /* Maxpacket and other transfer characteristics vary by speed. */
 static struct usb_endpoint_descriptor *
 fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
-		struct usb_endpoint_descriptor *hs)
+		struct usb_endpoint_descriptor *hs,
+		struct usb_endpoint_descriptor *ss)
 {
+	if (g->speed >= USB_SPEED_SUPER)
+		return ss;
 	if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
 		return hs;
 	return fs;
-- 
2.53.0