// 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 * talk to many USB gadgets, but the gadgets are only able to communicate * to one host. * * * (C) Copyright 2002-2004 by David Brownell * All Rights Reserved. */ #ifndef __LINUX_USB_GADGET_H #define __LINUX_USB_GADGET_H #include <linux/configfs.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 * @is_last: Indicates if this is the last request of a stream_id before * switching to a different stream (required for DWC3 controllers). * @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 is_last:1; 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 endpoint. * @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 (*func_wakeup)(struct usb_gadget *gadget, int intf_id); int (*set_remote_wakeup)(struct usb_gadget *, int set); 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); void (*udc_set_ssp_rate)(struct usb_gadget *gadget, enum usb_ssp_rate rate); void (*udc_async_callbacks)(struct usb_gadget *gadget, bool enable); 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); }; /** * struct usb_gadget - represents a usb 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. * @ssp_rate: Current connected SuperSpeed Plus signaling rate and lane count. * @max_ssp_rate: Maximum SuperSpeed Plus signaling rate and lane count the UDC * can handle. The UDC must support this and all slower speeds and lower * number of lanes. * @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. * @wakeup_capable: True if gadget is capable of sending remote wakeup. * @wakeup_armed: True if gadget is armed by the host for remote wakeup. * @irq: the interrupt number for device controller. * @id_number: a unique ID number for ensuring that gadget names are distinct * * 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; /* USB SuperSpeed Plus only */ enum usb_ssp_rate ssp_rate; enum usb_ssp_rate max_ssp_rate; 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; unsigned wakeup_capable:1; unsigned wakeup_armed:1; int irq; int id_number; }; #define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) /* Interface to the device model */ 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); } static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget) { get_device(&gadget->dev); return gadget; } static inline void usb_put_gadget(struct usb_gadget *gadget) { put_device(&gadget->dev); } extern void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget, void (*release)(struct device *dev)); extern int usb_add_gadget(struct usb_gadget *gadget); extern void usb_del_gadget(struct usb_gadget *gadget); /* Legacy device-model interface */ 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); /* 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); 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_remote_wakeup(struct usb_gadget *gadget, int set); 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); int usb_gadget_check_config(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_remote_wakeup(struct usb_gadget *gadget, int set) { 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; } static inline int usb_gadget_check_config(struct usb_gadget *gadget) { return 0; } #endif /* CONFIG_USB_GADGET */ /*-------------------------------------------------------------------------*/ /** * struct usb_gadget_driver - driver for usb gadget 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. * @match_existing_only: If udc is not found, return an error and fail * the driver registration * @is_bound: Allow a driver to be bound to only one gadget * * 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; unsigned match_existing_only:1; bool is_bound:1; }; /*-------------------------------------------------------------------------*/ /* driver modules register and unregister, as usual. * these calls must be made in a context that can sleep. * * A gadget driver can be bound to only one gadget at a time. */ /** * usb_gadget_register_driver_owner - register a gadget driver * @driver: the driver being registered * @owner: the driver module * @mod_name: the driver module's build name * Context: can sleep * * Call this in your gadget driver's module initialization function, * to tell the underlying UDC 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. * * Use the macro defined below instead of calling this directly. */ int usb_gadget_register_driver_owner(struct usb_gadget_driver *driver, struct module *owner, const char *mod_name); /* use a define to avoid include chaining to get THIS_MODULE & friends */ #define usb_gadget_register_driver(driver) \ usb_gadget_register_driver_owner(driver, THIS_MODULE, KBUILD_MODNAME) /** * 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 be in exit sections, so may not be linked in some kernels. */ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); /*-------------------------------------------------------------------------*/ /* 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[]; }; /* 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); /* check if the given language identifier is valid */ bool usb_validate_langid(u16 langid); struct gadget_string { struct config_item item; struct list_head list; char string[USB_MAX_STRING_LEN]; struct usb_string usb_string; }; #define to_gadget_string(str_item)\ container_of(str_item, struct gadget_string, item) /*-------------------------------------------------------------------------*/ /* 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 */