drivers/usb/gadget/function/f_eem.c
Source file repositories/reference/linux-study-clean/drivers/usb/gadget/function/f_eem.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/usb/gadget/function/f_eem.c- Extension
.c- Size
- 16925 bytes
- Lines
- 688
- Domain
- Driver Families
- Bucket
- drivers/usb
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/cleanup.hlinux/kernel.hlinux/module.hlinux/device.hlinux/etherdevice.hlinux/crc32.hlinux/slab.hu_ether.hu_ether_configfs.hu_eem.h
Detected Declarations
struct f_eemstruct in_contextfunction eem_setupfunction eem_set_altfunction eem_disablefunction eem_bindfunction scoped_guardfunction eem_cmd_completefunction eem_unwrapfunction eem_free_instfunction eem_freefunction eem_unbind
Annotated Snippet
struct f_eem {
struct gether port;
u8 ctrl_id;
};
struct in_context {
struct sk_buff *skb;
struct usb_ep *ep;
};
static inline struct f_eem *func_to_eem(struct usb_function *f)
{
return container_of(f, struct f_eem, port.func);
}
/*-------------------------------------------------------------------------*/
/* interface descriptor: */
static struct usb_interface_descriptor eem_intf = {
.bLength = sizeof eem_intf,
.bDescriptorType = USB_DT_INTERFACE,
/* .bInterfaceNumber = DYNAMIC */
.bNumEndpoints = 2,
.bInterfaceClass = USB_CLASS_COMM,
.bInterfaceSubClass = USB_CDC_SUBCLASS_EEM,
.bInterfaceProtocol = USB_CDC_PROTO_EEM,
/* .iInterface = DYNAMIC */
};
/* full speed support: */
static struct usb_endpoint_descriptor eem_fs_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
};
static struct usb_endpoint_descriptor eem_fs_out_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_OUT,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
};
static struct usb_descriptor_header *eem_fs_function[] = {
/* CDC EEM control descriptors */
(struct usb_descriptor_header *) &eem_intf,
(struct usb_descriptor_header *) &eem_fs_in_desc,
(struct usb_descriptor_header *) &eem_fs_out_desc,
NULL,
};
/* high speed support: */
static struct usb_endpoint_descriptor eem_hs_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512),
};
static struct usb_endpoint_descriptor eem_hs_out_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_OUT,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512),
};
static struct usb_descriptor_header *eem_hs_function[] = {
/* CDC EEM control descriptors */
(struct usb_descriptor_header *) &eem_intf,
(struct usb_descriptor_header *) &eem_hs_in_desc,
(struct usb_descriptor_header *) &eem_hs_out_desc,
NULL,
};
/* super speed support: */
static struct usb_endpoint_descriptor eem_ss_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
Annotation
- Immediate include surface: `linux/cleanup.h`, `linux/kernel.h`, `linux/module.h`, `linux/device.h`, `linux/etherdevice.h`, `linux/crc32.h`, `linux/slab.h`, `u_ether.h`.
- Detected declarations: `struct f_eem`, `struct in_context`, `function eem_setup`, `function eem_set_alt`, `function eem_disable`, `function eem_bind`, `function scoped_guard`, `function eem_cmd_complete`, `function eem_unwrap`, `function eem_free_inst`.
- Atlas domain: Driver Families / drivers/usb.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.