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linux-headers/include/linux/usb/gadget.h

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// 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.
* @frame_number: Reports the interval number in (micro)frame in which the
* isochronous transfer was transmitted or received.
* @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;
unsigned frame_number; /* ISO ONLY */
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 */
__u8 besl_baseline; /* Recommended baseline BESL (0-15) */
__u8 besl_deep; /* Recommended deep BESL (0-15) */
#define USB_DEFAULT_BESL_UNSPECIFIED 0xFF /* No recommended value */
};
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_gadget *,
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.
* @irq: the interrupt number for device controller.
*
* 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;
int irq;
};
#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 */
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