v4.19.13 snapshot.
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
new file mode 100644
index 0000000..e5cd84a
--- /dev/null
+++ b/include/linux/usb/gadget.h
@@ -0,0 +1,887 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * <linux/usb/gadget.h>
+ *
+ * We call the USB code inside a Linux-based peripheral device a "gadget"
+ * driver, except for the hardware-specific bus glue. One USB host can
+ * master many USB gadgets, but the gadgets are only slaved to one host.
+ *
+ *
+ * (C) Copyright 2002-2004 by David Brownell
+ * All Rights Reserved.
+ *
+ * This software is licensed under the GNU GPL version 2.
+ */
+
+#ifndef __LINUX_USB_GADGET_H
+#define __LINUX_USB_GADGET_H
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/scatterlist.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <linux/usb/ch9.h>
+
+#define UDC_TRACE_STR_MAX 512
+
+struct usb_ep;
+
+/**
+ * struct usb_request - describes one i/o request
+ * @buf: Buffer used for data. Always provide this; some controllers
+ * only use PIO, or don't use DMA for some endpoints.
+ * @dma: DMA address corresponding to 'buf'. If you don't set this
+ * field, and the usb controller needs one, it is responsible
+ * for mapping and unmapping the buffer.
+ * @sg: a scatterlist for SG-capable controllers.
+ * @num_sgs: number of SG entries
+ * @num_mapped_sgs: number of SG entries mapped to DMA (internal)
+ * @length: Length of that data
+ * @stream_id: The stream id, when USB3.0 bulk streams are being used
+ * @no_interrupt: If true, hints that no completion irq is needed.
+ * Helpful sometimes with deep request queues that are handled
+ * directly by DMA controllers.
+ * @zero: If true, when writing data, makes the last packet be "short"
+ * by adding a zero length packet as needed;
+ * @short_not_ok: When reading data, makes short packets be
+ * treated as errors (queue stops advancing till cleanup).
+ * @dma_mapped: Indicates if request has been mapped to DMA (internal)
+ * @complete: Function called when request completes, so this request and
+ * its buffer may be re-used. The function will always be called with
+ * interrupts disabled, and it must not sleep.
+ * Reads terminate with a short packet, or when the buffer fills,
+ * whichever comes first. When writes terminate, some data bytes
+ * will usually still be in flight (often in a hardware fifo).
+ * Errors (for reads or writes) stop the queue from advancing
+ * until the completion function returns, so that any transfers
+ * invalidated by the error may first be dequeued.
+ * @context: For use by the completion callback
+ * @list: For use by the gadget driver.
+ * @status: Reports completion code, zero or a negative errno.
+ * Normally, faults block the transfer queue from advancing until
+ * the completion callback returns.
+ * Code "-ESHUTDOWN" indicates completion caused by device disconnect,
+ * or when the driver disabled the endpoint.
+ * @actual: Reports bytes transferred to/from the buffer. For reads (OUT
+ * transfers) this may be less than the requested length. If the
+ * short_not_ok flag is set, short reads are treated as errors
+ * even when status otherwise indicates successful completion.
+ * Note that for writes (IN transfers) some data bytes may still
+ * reside in a device-side FIFO when the request is reported as
+ * complete.
+ *
+ * These are allocated/freed through the endpoint they're used with. The
+ * hardware's driver can add extra per-request data to the memory it returns,
+ * which often avoids separate memory allocations (potential failures),
+ * later when the request is queued.
+ *
+ * Request flags affect request handling, such as whether a zero length
+ * packet is written (the "zero" flag), whether a short read should be
+ * treated as an error (blocking request queue advance, the "short_not_ok"
+ * flag), or hinting that an interrupt is not required (the "no_interrupt"
+ * flag, for use with deep request queues).
+ *
+ * Bulk endpoints can use any size buffers, and can also be used for interrupt
+ * transfers. interrupt-only endpoints can be much less functional.
+ *
+ * NOTE: this is analogous to 'struct urb' on the host side, except that
+ * it's thinner and promotes more pre-allocation.
+ */
+
+struct usb_request {
+ void *buf;
+ unsigned length;
+ dma_addr_t dma;
+
+ struct scatterlist *sg;
+ unsigned num_sgs;
+ unsigned num_mapped_sgs;
+
+ unsigned stream_id:16;
+ unsigned no_interrupt:1;
+ unsigned zero:1;
+ unsigned short_not_ok:1;
+ unsigned dma_mapped:1;
+
+ void (*complete)(struct usb_ep *ep,
+ struct usb_request *req);
+ void *context;
+ struct list_head list;
+
+ int status;
+ unsigned actual;
+};
+
+/*-------------------------------------------------------------------------*/
+
+/* endpoint-specific parts of the api to the usb controller hardware.
+ * unlike the urb model, (de)multiplexing layers are not required.
+ * (so this api could slash overhead if used on the host side...)
+ *
+ * note that device side usb controllers commonly differ in how many
+ * endpoints they support, as well as their capabilities.
+ */
+struct usb_ep_ops {
+ int (*enable) (struct usb_ep *ep,
+ const struct usb_endpoint_descriptor *desc);
+ int (*disable) (struct usb_ep *ep);
+ void (*dispose) (struct usb_ep *ep);
+
+ struct usb_request *(*alloc_request) (struct usb_ep *ep,
+ gfp_t gfp_flags);
+ void (*free_request) (struct usb_ep *ep, struct usb_request *req);
+
+ int (*queue) (struct usb_ep *ep, struct usb_request *req,
+ gfp_t gfp_flags);
+ int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
+
+ int (*set_halt) (struct usb_ep *ep, int value);
+ int (*set_wedge) (struct usb_ep *ep);
+
+ int (*fifo_status) (struct usb_ep *ep);
+ void (*fifo_flush) (struct usb_ep *ep);
+};
+
+/**
+ * struct usb_ep_caps - endpoint capabilities description
+ * @type_control:Endpoint supports control type (reserved for ep0).
+ * @type_iso:Endpoint supports isochronous transfers.
+ * @type_bulk:Endpoint supports bulk transfers.
+ * @type_int:Endpoint supports interrupt transfers.
+ * @dir_in:Endpoint supports IN direction.
+ * @dir_out:Endpoint supports OUT direction.
+ */
+struct usb_ep_caps {
+ unsigned type_control:1;
+ unsigned type_iso:1;
+ unsigned type_bulk:1;
+ unsigned type_int:1;
+ unsigned dir_in:1;
+ unsigned dir_out:1;
+};
+
+#define USB_EP_CAPS_TYPE_CONTROL 0x01
+#define USB_EP_CAPS_TYPE_ISO 0x02
+#define USB_EP_CAPS_TYPE_BULK 0x04
+#define USB_EP_CAPS_TYPE_INT 0x08
+#define USB_EP_CAPS_TYPE_ALL \
+ (USB_EP_CAPS_TYPE_ISO | USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
+#define USB_EP_CAPS_DIR_IN 0x01
+#define USB_EP_CAPS_DIR_OUT 0x02
+#define USB_EP_CAPS_DIR_ALL (USB_EP_CAPS_DIR_IN | USB_EP_CAPS_DIR_OUT)
+
+#define USB_EP_CAPS(_type, _dir) \
+ { \
+ .type_control = !!(_type & USB_EP_CAPS_TYPE_CONTROL), \
+ .type_iso = !!(_type & USB_EP_CAPS_TYPE_ISO), \
+ .type_bulk = !!(_type & USB_EP_CAPS_TYPE_BULK), \
+ .type_int = !!(_type & USB_EP_CAPS_TYPE_INT), \
+ .dir_in = !!(_dir & USB_EP_CAPS_DIR_IN), \
+ .dir_out = !!(_dir & USB_EP_CAPS_DIR_OUT), \
+ }
+
+/**
+ * struct usb_ep - device side representation of USB endpoint
+ * @name:identifier for the endpoint, such as "ep-a" or "ep9in-bulk"
+ * @ops: Function pointers used to access hardware-specific operations.
+ * @ep_list:the gadget's ep_list holds all of its endpoints
+ * @caps:The structure describing types and directions supported by endoint.
+ * @enabled: The current endpoint enabled/disabled state.
+ * @claimed: True if this endpoint is claimed by a function.
+ * @maxpacket:The maximum packet size used on this endpoint. The initial
+ * value can sometimes be reduced (hardware allowing), according to
+ * the endpoint descriptor used to configure the endpoint.
+ * @maxpacket_limit:The maximum packet size value which can be handled by this
+ * endpoint. It's set once by UDC driver when endpoint is initialized, and
+ * should not be changed. Should not be confused with maxpacket.
+ * @max_streams: The maximum number of streams supported
+ * by this EP (0 - 16, actual number is 2^n)
+ * @mult: multiplier, 'mult' value for SS Isoc EPs
+ * @maxburst: the maximum number of bursts supported by this EP (for usb3)
+ * @driver_data:for use by the gadget driver.
+ * @address: used to identify the endpoint when finding descriptor that
+ * matches connection speed
+ * @desc: endpoint descriptor. This pointer is set before the endpoint is
+ * enabled and remains valid until the endpoint is disabled.
+ * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
+ * descriptor that is used to configure the endpoint
+ *
+ * the bus controller driver lists all the general purpose endpoints in
+ * gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
+ * and is accessed only in response to a driver setup() callback.
+ */
+
+struct usb_ep {
+ void *driver_data;
+
+ const char *name;
+ const struct usb_ep_ops *ops;
+ struct list_head ep_list;
+ struct usb_ep_caps caps;
+ bool claimed;
+ bool enabled;
+ unsigned maxpacket:16;
+ unsigned maxpacket_limit:16;
+ unsigned max_streams:16;
+ unsigned mult:2;
+ unsigned maxburst:5;
+ u8 address;
+ const struct usb_endpoint_descriptor *desc;
+ const struct usb_ss_ep_comp_descriptor *comp_desc;
+};
+
+/*-------------------------------------------------------------------------*/
+
+#if IS_ENABLED(CONFIG_USB_GADGET)
+void usb_ep_set_maxpacket_limit(struct usb_ep *ep, unsigned maxpacket_limit);
+int usb_ep_enable(struct usb_ep *ep);
+int usb_ep_disable(struct usb_ep *ep);
+struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
+void usb_ep_free_request(struct usb_ep *ep, struct usb_request *req);
+int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags);
+int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req);
+int usb_ep_set_halt(struct usb_ep *ep);
+int usb_ep_clear_halt(struct usb_ep *ep);
+int usb_ep_set_wedge(struct usb_ep *ep);
+int usb_ep_fifo_status(struct usb_ep *ep);
+void usb_ep_fifo_flush(struct usb_ep *ep);
+#else
+static inline void usb_ep_set_maxpacket_limit(struct usb_ep *ep,
+ unsigned maxpacket_limit)
+{ }
+static inline int usb_ep_enable(struct usb_ep *ep)
+{ return 0; }
+static inline int usb_ep_disable(struct usb_ep *ep)
+{ return 0; }
+static inline struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
+ gfp_t gfp_flags)
+{ return NULL; }
+static inline void usb_ep_free_request(struct usb_ep *ep,
+ struct usb_request *req)
+{ }
+static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req,
+ gfp_t gfp_flags)
+{ return 0; }
+static inline int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
+{ return 0; }
+static inline int usb_ep_set_halt(struct usb_ep *ep)
+{ return 0; }
+static inline int usb_ep_clear_halt(struct usb_ep *ep)
+{ return 0; }
+static inline int usb_ep_set_wedge(struct usb_ep *ep)
+{ return 0; }
+static inline int usb_ep_fifo_status(struct usb_ep *ep)
+{ return 0; }
+static inline void usb_ep_fifo_flush(struct usb_ep *ep)
+{ }
+#endif /* USB_GADGET */
+
+/*-------------------------------------------------------------------------*/
+
+struct usb_dcd_config_params {
+ __u8 bU1devExitLat; /* U1 Device exit Latency */
+#define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
+ __le16 bU2DevExitLat; /* U2 Device exit Latency */
+#define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
+};
+
+
+struct usb_gadget;
+struct usb_gadget_driver;
+struct usb_udc;
+
+/* the rest of the api to the controller hardware: device operations,
+ * which don't involve endpoints (or i/o).
+ */
+struct usb_gadget_ops {
+ int (*get_frame)(struct usb_gadget *);
+ int (*wakeup)(struct usb_gadget *);
+ int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
+ int (*vbus_session) (struct usb_gadget *, int is_active);
+ int (*vbus_draw) (struct usb_gadget *, unsigned mA);
+ int (*pullup) (struct usb_gadget *, int is_on);
+ int (*ioctl)(struct usb_gadget *,
+ unsigned code, unsigned long param);
+ void (*get_config_params)(struct usb_dcd_config_params *);
+ int (*udc_start)(struct usb_gadget *,
+ struct usb_gadget_driver *);
+ int (*udc_stop)(struct usb_gadget *);
+ void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
+ struct usb_ep *(*match_ep)(struct usb_gadget *,
+ struct usb_endpoint_descriptor *,
+ struct usb_ss_ep_comp_descriptor *);
+};
+
+/**
+ * struct usb_gadget - represents a usb slave device
+ * @work: (internal use) Workqueue to be used for sysfs_notify()
+ * @udc: struct usb_udc pointer for this gadget
+ * @ops: Function pointers used to access hardware-specific operations.
+ * @ep0: Endpoint zero, used when reading or writing responses to
+ * driver setup() requests
+ * @ep_list: List of other endpoints supported by the device.
+ * @speed: Speed of current connection to USB host.
+ * @max_speed: Maximal speed the UDC can handle. UDC must support this
+ * and all slower speeds.
+ * @state: the state we are now (attached, suspended, configured, etc)
+ * @name: Identifies the controller hardware type. Used in diagnostics
+ * and sometimes configuration.
+ * @dev: Driver model state for this abstract device.
+ * @isoch_delay: value from Set Isoch Delay request. Only valid on SS/SSP
+ * @out_epnum: last used out ep number
+ * @in_epnum: last used in ep number
+ * @mA: last set mA value
+ * @otg_caps: OTG capabilities of this gadget.
+ * @sg_supported: true if we can handle scatter-gather
+ * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
+ * gadget driver must provide a USB OTG descriptor.
+ * @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
+ * is in the Mini-AB jack, and HNP has been used to switch roles
+ * so that the "A" device currently acts as A-Peripheral, not A-Host.
+ * @a_hnp_support: OTG device feature flag, indicating that the A-Host
+ * supports HNP at this port.
+ * @a_alt_hnp_support: OTG device feature flag, indicating that the A-Host
+ * only supports HNP on a different root port.
+ * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
+ * enabled HNP support.
+ * @hnp_polling_support: OTG device feature flag, indicating if the OTG device
+ * in peripheral mode can support HNP polling.
+ * @host_request_flag: OTG device feature flag, indicating if A-Peripheral
+ * or B-Peripheral wants to take host role.
+ * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
+ * MaxPacketSize.
+ * @quirk_altset_not_supp: UDC controller doesn't support alt settings.
+ * @quirk_stall_not_supp: UDC controller doesn't support stalling.
+ * @quirk_zlp_not_supp: UDC controller doesn't support ZLP.
+ * @quirk_avoids_skb_reserve: udc/platform wants to avoid skb_reserve() in
+ * u_ether.c to improve performance.
+ * @is_selfpowered: if the gadget is self-powered.
+ * @deactivated: True if gadget is deactivated - in deactivated state it cannot
+ * be connected.
+ * @connected: True if gadget is connected.
+ * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
+ * indicates that it supports LPM as per the LPM ECN & errata.
+ *
+ * Gadgets have a mostly-portable "gadget driver" implementing device
+ * functions, handling all usb configurations and interfaces. Gadget
+ * drivers talk to hardware-specific code indirectly, through ops vectors.
+ * That insulates the gadget driver from hardware details, and packages
+ * the hardware endpoints through generic i/o queues. The "usb_gadget"
+ * and "usb_ep" interfaces provide that insulation from the hardware.
+ *
+ * Except for the driver data, all fields in this structure are
+ * read-only to the gadget driver. That driver data is part of the
+ * "driver model" infrastructure in 2.6 (and later) kernels, and for
+ * earlier systems is grouped in a similar structure that's not known
+ * to the rest of the kernel.
+ *
+ * Values of the three OTG device feature flags are updated before the
+ * setup() call corresponding to USB_REQ_SET_CONFIGURATION, and before
+ * driver suspend() calls. They are valid only when is_otg, and when the
+ * device is acting as a B-Peripheral (so is_a_peripheral is false).
+ */
+struct usb_gadget {
+ struct work_struct work;
+ struct usb_udc *udc;
+ /* readonly to gadget driver */
+ const struct usb_gadget_ops *ops;
+ struct usb_ep *ep0;
+ struct list_head ep_list; /* of usb_ep */
+ enum usb_device_speed speed;
+ enum usb_device_speed max_speed;
+ enum usb_device_state state;
+ const char *name;
+ struct device dev;
+ unsigned isoch_delay;
+ unsigned out_epnum;
+ unsigned in_epnum;
+ unsigned mA;
+ struct usb_otg_caps *otg_caps;
+
+ unsigned sg_supported:1;
+ unsigned is_otg:1;
+ unsigned is_a_peripheral:1;
+ unsigned b_hnp_enable:1;
+ unsigned a_hnp_support:1;
+ unsigned a_alt_hnp_support:1;
+ unsigned hnp_polling_support:1;
+ unsigned host_request_flag:1;
+ unsigned quirk_ep_out_aligned_size:1;
+ unsigned quirk_altset_not_supp:1;
+ unsigned quirk_stall_not_supp:1;
+ unsigned quirk_zlp_not_supp:1;
+ unsigned quirk_avoids_skb_reserve:1;
+ unsigned is_selfpowered:1;
+ unsigned deactivated:1;
+ unsigned connected:1;
+ unsigned lpm_capable:1;
+};
+#define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
+
+static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
+ { dev_set_drvdata(&gadget->dev, data); }
+static inline void *get_gadget_data(struct usb_gadget *gadget)
+ { return dev_get_drvdata(&gadget->dev); }
+static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
+{
+ return container_of(dev, struct usb_gadget, dev);
+}
+
+/* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
+#define gadget_for_each_ep(tmp, gadget) \
+ list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
+
+/**
+ * usb_ep_align - returns @len aligned to ep's maxpacketsize.
+ * @ep: the endpoint whose maxpacketsize is used to align @len
+ * @len: buffer size's length to align to @ep's maxpacketsize
+ *
+ * This helper is used to align buffer's size to an ep's maxpacketsize.
+ */
+static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
+{
+ int max_packet_size = (size_t)usb_endpoint_maxp(ep->desc) & 0x7ff;
+
+ return round_up(len, max_packet_size);
+}
+
+/**
+ * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
+ * requires quirk_ep_out_aligned_size, otherwise returns len.
+ * @g: controller to check for quirk
+ * @ep: the endpoint whose maxpacketsize is used to align @len
+ * @len: buffer size's length to align to @ep's maxpacketsize
+ *
+ * This helper is used in case it's required for any reason to check and maybe
+ * align buffer's size to an ep's maxpacketsize.
+ */
+static inline size_t
+usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
+{
+ return g->quirk_ep_out_aligned_size ? usb_ep_align(ep, len) : len;
+}
+
+/**
+ * gadget_is_altset_supported - return true iff the hardware supports
+ * altsettings
+ * @g: controller to check for quirk
+ */
+static inline int gadget_is_altset_supported(struct usb_gadget *g)
+{
+ return !g->quirk_altset_not_supp;
+}
+
+/**
+ * gadget_is_stall_supported - return true iff the hardware supports stalling
+ * @g: controller to check for quirk
+ */
+static inline int gadget_is_stall_supported(struct usb_gadget *g)
+{
+ return !g->quirk_stall_not_supp;
+}
+
+/**
+ * gadget_is_zlp_supported - return true iff the hardware supports zlp
+ * @g: controller to check for quirk
+ */
+static inline int gadget_is_zlp_supported(struct usb_gadget *g)
+{
+ return !g->quirk_zlp_not_supp;
+}
+
+/**
+ * gadget_avoids_skb_reserve - return true iff the hardware would like to avoid
+ * skb_reserve to improve performance.
+ * @g: controller to check for quirk
+ */
+static inline int gadget_avoids_skb_reserve(struct usb_gadget *g)
+{
+ return g->quirk_avoids_skb_reserve;
+}
+
+/**
+ * gadget_is_dualspeed - return true iff the hardware handles high speed
+ * @g: controller that might support both high and full speeds
+ */
+static inline int gadget_is_dualspeed(struct usb_gadget *g)
+{
+ return g->max_speed >= USB_SPEED_HIGH;
+}
+
+/**
+ * gadget_is_superspeed() - return true if the hardware handles superspeed
+ * @g: controller that might support superspeed
+ */
+static inline int gadget_is_superspeed(struct usb_gadget *g)
+{
+ return g->max_speed >= USB_SPEED_SUPER;
+}
+
+/**
+ * gadget_is_superspeed_plus() - return true if the hardware handles
+ * superspeed plus
+ * @g: controller that might support superspeed plus
+ */
+static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
+{
+ return g->max_speed >= USB_SPEED_SUPER_PLUS;
+}
+
+/**
+ * gadget_is_otg - return true iff the hardware is OTG-ready
+ * @g: controller that might have a Mini-AB connector
+ *
+ * This is a runtime test, since kernels with a USB-OTG stack sometimes
+ * run on boards which only have a Mini-B (or Mini-A) connector.
+ */
+static inline int gadget_is_otg(struct usb_gadget *g)
+{
+#ifdef CONFIG_USB_OTG
+ return g->is_otg;
+#else
+ return 0;
+#endif
+}
+
+/*-------------------------------------------------------------------------*/
+
+#if IS_ENABLED(CONFIG_USB_GADGET)
+int usb_gadget_frame_number(struct usb_gadget *gadget);
+int usb_gadget_wakeup(struct usb_gadget *gadget);
+int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
+int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
+int usb_gadget_vbus_connect(struct usb_gadget *gadget);
+int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA);
+int usb_gadget_vbus_disconnect(struct usb_gadget *gadget);
+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);
+#else
+static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_vbus_connect(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
+{ return 0; }
+static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_connect(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
+{ return 0; }
+static inline int usb_gadget_activate(struct usb_gadget *gadget)
+{ return 0; }
+#endif /* CONFIG_USB_GADGET */
+
+/*-------------------------------------------------------------------------*/
+
+/**
+ * struct usb_gadget_driver - driver for usb 'slave' devices
+ * @function: String describing the gadget's function
+ * @max_speed: Highest speed the driver handles.
+ * @setup: Invoked for ep0 control requests that aren't handled by
+ * the hardware level driver. Most calls must be handled by
+ * the gadget driver, including descriptor and configuration
+ * management. The 16 bit members of the setup data are in
+ * USB byte order. Called in_interrupt; this may not sleep. Driver
+ * queues a response to ep0, or returns negative to stall.
+ * @disconnect: Invoked after all transfers have been stopped,
+ * when the host is disconnected. May be called in_interrupt; this
+ * may not sleep. Some devices can't detect disconnect, so this might
+ * not be called except as part of controller shutdown.
+ * @bind: the driver's bind callback
+ * @unbind: Invoked when the driver is unbound from a gadget,
+ * usually from rmmod (after a disconnect is reported).
+ * Called in a context that permits sleeping.
+ * @suspend: Invoked on USB suspend. May be called in_interrupt.
+ * @resume: Invoked on USB resume. May be called in_interrupt.
+ * @reset: Invoked on USB bus reset. It is mandatory for all gadget drivers
+ * and should be called in_interrupt.
+ * @driver: Driver model state for this driver.
+ * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
+ * this driver will be bound to any available UDC.
+ * @pending: UDC core private data used for deferred probe of this driver.
+ * @match_existing_only: If udc is not found, return an error and don't add this
+ * gadget driver to list of pending driver
+ *
+ * Devices are disabled till a gadget driver successfully bind()s, which
+ * means the driver will handle setup() requests needed to enumerate (and
+ * meet "chapter 9" requirements) then do some useful work.
+ *
+ * If gadget->is_otg is true, the gadget driver must provide an OTG
+ * descriptor during enumeration, or else fail the bind() call. In such
+ * cases, no USB traffic may flow until both bind() returns without
+ * having called usb_gadget_disconnect(), and the USB host stack has
+ * initialized.
+ *
+ * Drivers use hardware-specific knowledge to configure the usb hardware.
+ * endpoint addressing is only one of several hardware characteristics that
+ * are in descriptors the ep0 implementation returns from setup() calls.
+ *
+ * Except for ep0 implementation, most driver code shouldn't need change to
+ * run on top of different usb controllers. It'll use endpoints set up by
+ * that ep0 implementation.
+ *
+ * The usb controller driver handles a few standard usb requests. Those
+ * include set_address, and feature flags for devices, interfaces, and
+ * endpoints (the get_status, set_feature, and clear_feature requests).
+ *
+ * Accordingly, the driver's setup() callback must always implement all
+ * get_descriptor requests, returning at least a device descriptor and
+ * a configuration descriptor. Drivers must make sure the endpoint
+ * descriptors match any hardware constraints. Some hardware also constrains
+ * other descriptors. (The pxa250 allows only configurations 1, 2, or 3).
+ *
+ * The driver's setup() callback must also implement set_configuration,
+ * and should also implement set_interface, get_configuration, and
+ * get_interface. Setting a configuration (or interface) is where
+ * endpoints should be activated or (config 0) shut down.
+ *
+ * (Note that only the default control endpoint is supported. Neither
+ * hosts nor devices generally support control traffic except to ep0.)
+ *
+ * Most devices will ignore USB suspend/resume operations, and so will
+ * not provide those callbacks. However, some may need to change modes
+ * when the host is not longer directing those activities. For example,
+ * local controls (buttons, dials, etc) may need to be re-enabled since
+ * the (remote) host can't do that any longer; or an error state might
+ * be cleared, to make the device behave identically whether or not
+ * power is maintained.
+ */
+struct usb_gadget_driver {
+ char *function;
+ enum usb_device_speed max_speed;
+ int (*bind)(struct usb_gadget *gadget,
+ struct usb_gadget_driver *driver);
+ void (*unbind)(struct usb_gadget *);
+ int (*setup)(struct usb_gadget *,
+ const struct usb_ctrlrequest *);
+ void (*disconnect)(struct usb_gadget *);
+ void (*suspend)(struct usb_gadget *);
+ void (*resume)(struct usb_gadget *);
+ void (*reset)(struct usb_gadget *);
+
+ /* FIXME support safe rmmod */
+ struct device_driver driver;
+
+ char *udc_name;
+ struct list_head pending;
+ unsigned match_existing_only:1;
+};
+
+
+
+/*-------------------------------------------------------------------------*/
+
+/* driver modules register and unregister, as usual.
+ * these calls must be made in a context that can sleep.
+ *
+ * these will usually be implemented directly by the hardware-dependent
+ * usb bus interface driver, which will only support a single driver.
+ */
+
+/**
+ * usb_gadget_probe_driver - probe a gadget driver
+ * @driver: the driver being registered
+ * Context: can sleep
+ *
+ * Call this in your gadget driver's module initialization function,
+ * to tell the underlying usb controller driver about your driver.
+ * The @bind() function will be called to bind it to a gadget before this
+ * registration call returns. It's expected that the @bind() function will
+ * be in init sections.
+ */
+int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
+
+/**
+ * usb_gadget_unregister_driver - unregister a gadget driver
+ * @driver:the driver being unregistered
+ * Context: can sleep
+ *
+ * Call this in your gadget driver's module cleanup function,
+ * to tell the underlying usb controller that your driver is
+ * going away. If the controller is connected to a USB host,
+ * it will first disconnect(). The driver is also requested
+ * to unbind() and clean up any device state, before this procedure
+ * finally returns. It's expected that the unbind() functions
+ * will in in exit sections, so may not be linked in some kernels.
+ */
+int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
+
+extern int usb_add_gadget_udc_release(struct device *parent,
+ struct usb_gadget *gadget, void (*release)(struct device *dev));
+extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
+extern void usb_del_gadget_udc(struct usb_gadget *gadget);
+extern char *usb_get_gadget_udc_name(void);
+
+/*-------------------------------------------------------------------------*/
+
+/* utility to simplify dealing with string descriptors */
+
+/**
+ * struct usb_string - wraps a C string and its USB id
+ * @id:the (nonzero) ID for this string
+ * @s:the string, in UTF-8 encoding
+ *
+ * If you're using usb_gadget_get_string(), use this to wrap a string
+ * together with its ID.
+ */
+struct usb_string {
+ u8 id;
+ const char *s;
+};
+
+/**
+ * struct usb_gadget_strings - a set of USB strings in a given language
+ * @language:identifies the strings' language (0x0409 for en-us)
+ * @strings:array of strings with their ids
+ *
+ * If you're using usb_gadget_get_string(), use this to wrap all the
+ * strings for a given language.
+ */
+struct usb_gadget_strings {
+ u16 language; /* 0x0409 for en-us */
+ struct usb_string *strings;
+};
+
+struct usb_gadget_string_container {
+ struct list_head list;
+ u8 *stash[0];
+};
+
+/* put descriptor for string with that id into buf (buflen >= 256) */
+int usb_gadget_get_string(const struct usb_gadget_strings *table, int id, u8 *buf);
+
+/*-------------------------------------------------------------------------*/
+
+/* utility to simplify managing config descriptors */
+
+/* write vector of descriptors into buffer */
+int usb_descriptor_fillbuf(void *, unsigned,
+ const struct usb_descriptor_header **);
+
+/* build config descriptor from single descriptor vector */
+int usb_gadget_config_buf(const struct usb_config_descriptor *config,
+ void *buf, unsigned buflen, const struct usb_descriptor_header **desc);
+
+/* copy a NULL-terminated vector of descriptors */
+struct usb_descriptor_header **usb_copy_descriptors(
+ struct usb_descriptor_header **);
+
+/**
+ * usb_free_descriptors - free descriptors returned by usb_copy_descriptors()
+ * @v: vector of descriptors
+ */
+static inline void usb_free_descriptors(struct usb_descriptor_header **v)
+{
+ kfree(v);
+}
+
+struct usb_function;
+int usb_assign_descriptors(struct usb_function *f,
+ struct usb_descriptor_header **fs,
+ struct usb_descriptor_header **hs,
+ struct usb_descriptor_header **ss,
+ struct usb_descriptor_header **ssp);
+void usb_free_all_descriptors(struct usb_function *f);
+
+struct usb_descriptor_header *usb_otg_descriptor_alloc(
+ struct usb_gadget *gadget);
+int usb_otg_descriptor_init(struct usb_gadget *gadget,
+ struct usb_descriptor_header *otg_desc);
+/*-------------------------------------------------------------------------*/
+
+/* utility to simplify map/unmap of usb_requests to/from DMA */
+
+#ifdef CONFIG_HAS_DMA
+extern int usb_gadget_map_request_by_dev(struct device *dev,
+ struct usb_request *req, int is_in);
+extern int usb_gadget_map_request(struct usb_gadget *gadget,
+ struct usb_request *req, int is_in);
+
+extern void usb_gadget_unmap_request_by_dev(struct device *dev,
+ struct usb_request *req, int is_in);
+extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
+ struct usb_request *req, int is_in);
+#else /* !CONFIG_HAS_DMA */
+static inline int usb_gadget_map_request_by_dev(struct device *dev,
+ struct usb_request *req, int is_in) { return -ENOSYS; }
+static inline int usb_gadget_map_request(struct usb_gadget *gadget,
+ struct usb_request *req, int is_in) { return -ENOSYS; }
+
+static inline void usb_gadget_unmap_request_by_dev(struct device *dev,
+ struct usb_request *req, int is_in) { }
+static inline void usb_gadget_unmap_request(struct usb_gadget *gadget,
+ struct usb_request *req, int is_in) { }
+#endif /* !CONFIG_HAS_DMA */
+
+/*-------------------------------------------------------------------------*/
+
+/* utility to set gadget state properly */
+
+extern void usb_gadget_set_state(struct usb_gadget *gadget,
+ enum usb_device_state state);
+
+/*-------------------------------------------------------------------------*/
+
+/* utility to tell udc core that the bus reset occurs */
+extern void usb_gadget_udc_reset(struct usb_gadget *gadget,
+ struct usb_gadget_driver *driver);
+
+/*-------------------------------------------------------------------------*/
+
+/* utility to give requests back to the gadget layer */
+
+extern void usb_gadget_giveback_request(struct usb_ep *ep,
+ struct usb_request *req);
+
+/*-------------------------------------------------------------------------*/
+
+/* utility to find endpoint by name */
+
+extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,
+ const char *name);
+
+/*-------------------------------------------------------------------------*/
+
+/* utility to check if endpoint caps match descriptor needs */
+
+extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
+ struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
+ struct usb_ss_ep_comp_descriptor *ep_comp);
+
+/*-------------------------------------------------------------------------*/
+
+/* utility to update vbus status for udc core, it may be scheduled */
+extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
+
+/*-------------------------------------------------------------------------*/
+
+/* utility wrapping a simple endpoint selection policy */
+
+extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
+ struct usb_endpoint_descriptor *);
+
+
+extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
+ struct usb_endpoint_descriptor *,
+ struct usb_ss_ep_comp_descriptor *);
+
+extern void usb_ep_autoconfig_release(struct usb_ep *);
+
+extern void usb_ep_autoconfig_reset(struct usb_gadget *);
+
+#endif /* __LINUX_USB_GADGET_H */