[RFC v5 5/6] usb: gadget: udc: core: Introduce check_config to verify USB configuration

Wesley Cheng
2020-08-29T05:59:40Z

Some UDCs may have constraints on how many high bandwidth endpoints it can
support in a certain configuration. This API allows for the composite
driver to pass down the total number of endpoints to the UDC so it can verify
it has the required resources to support the configuration.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
---
drivers/usb/gadget/udc/core.c | 9 +++++++++
include/linux/usb/gadget.h | 2 ++
2 files changed, 11 insertions(+)

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index c33ad8a333ad..e006d69dff9b 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1001,6 +1001,15 @@ int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
}
EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc);

+int usb_gadget_check_config(struct usb_gadget *gadget, unsigned long ep_map)
+{
+ if (!gadget->ops->check_config)
+ return 0;
+
+ return gadget->ops->check_config(gadget, ep_map);
+}
+EXPORT_SYMBOL_GPL(usb_gadget_check_config);
+
/* ------------------------------------------------------------------------- */

static void usb_gadget_state_work(struct work_struct *work)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 52ce1f6b8f83..791ae5b352a1 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -326,6 +326,7 @@ struct usb_gadget_ops {
struct usb_ep *(*match_ep)(struct usb_gadget *,
struct usb_endpoint_descriptor *,
struct usb_ss_ep_comp_descriptor *);
+ int (*check_config)(struct usb_gadget *gadget, unsigned long ep_map);
};

/**
@@ -575,6 +576,7 @@ int usb_gadget_connect(struct usb_gadget *gadget);
int usb_gadget_disconnect(struct usb_gadget *gadget);
int usb_gadget_deactivate(struct usb_gadget *gadget);
int usb_gadget_activate(struct usb_gadget *gadget);
+int usb_gadget_check_config(struct usb_gadget *gadget, unsigned long ep_map);
#else
static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
{ return 0; }