cregit-Linux how code gets into the kernel

Release 4.11 drivers/usb/gadget/epautoconf.c

/*
 * epautoconf.c -- endpoint autoconfiguration for usb gadget drivers
 *
 * Copyright (C) 2004 David Brownell
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/device.h>

#include <linux/ctype.h>
#include <linux/string.h>

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

/**
 * usb_ep_autoconfig_ss() - choose an endpoint matching the ep
 * descriptor and ep companion descriptor
 * @gadget: The device to which the endpoint must belong.
 * @desc: Endpoint descriptor, with endpoint direction and transfer mode
 *    initialized.  For periodic transfers, the maximum packet
 *    size must also be initialized.  This is modified on
 *    success.
 * @ep_comp: Endpoint companion descriptor, with the required
 *    number of streams. Will be modified when the chosen EP
 *    supports a different number of streams.
 *
 * This routine replaces the usb_ep_autoconfig when needed
 * superspeed enhancments. If such enhancemnets are required,
 * the FD should call usb_ep_autoconfig_ss directly and provide
 * the additional ep_comp parameter.
 *
 * By choosing an endpoint to use with the specified descriptor,
 * this routine simplifies writing gadget drivers that work with
 * multiple USB device controllers.  The endpoint would be
 * passed later to usb_ep_enable(), along with some descriptor.
 *
 * That second descriptor won't always be the same as the first one.
 * For example, isochronous endpoints can be autoconfigured for high
 * bandwidth, and then used in several lower bandwidth altsettings.
 * Also, high and full speed descriptors will be different.
 *
 * Be sure to examine and test the results of autoconfiguration
 * on your hardware.  This code may not make the best choices
 * about how to use the USB controller, and it can't know all
 * the restrictions that may apply. Some combinations of driver
 * and hardware won't be able to autoconfigure.
 *
 * On success, this returns an claimed usb_ep, and modifies the endpoint
 * descriptor bEndpointAddress.  For bulk endpoints, the wMaxPacket value
 * is initialized as if the endpoint were used at full speed and
 * the bmAttribute field in the ep companion descriptor is
 * updated with the assigned number of streams if it is
 * different from the original value. To prevent the endpoint
 * from being returned by a later autoconfig call, claims it by
 * assigning ep->claimed to true.
 *
 * On failure, this returns a null endpoint descriptor.
 */

struct usb_ep *usb_ep_autoconfig_ss( struct usb_gadget *gadget, struct usb_endpoint_descriptor *desc, struct usb_ss_ep_comp_descriptor *ep_comp ) { struct usb_ep *ep; u8 type; type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; if (gadget->ops->match_ep) { ep = gadget->ops->match_ep(gadget, desc, ep_comp); if (ep) goto found_ep; } /* Second, look at endpoints until an unclaimed one looks usable */ list_for_each_entry (ep, &gadget->ep_list, ep_list) { if (usb_gadget_ep_match_desc(gadget, ep, desc, ep_comp)) goto found_ep; } /* Fail */ return NULL; found_ep: /* * If the protocol driver hasn't yet decided on wMaxPacketSize * and wants to know the maximum possible, provide the info. */ if (desc->wMaxPacketSize == 0) desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket_limit); /* report address */ desc->bEndpointAddress &= USB_DIR_IN; if (isdigit(ep->name[2])) { u8 num = simple_strtoul(&ep->name[2], NULL, 10); desc->bEndpointAddress |= num; } else if (desc->bEndpointAddress & USB_DIR_IN) { if (++gadget->in_epnum > 15) return NULL; desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum; } else { if (++gadget->out_epnum > 15) return NULL; desc->bEndpointAddress |= gadget->out_epnum; } /* report (variable) full speed bulk maxpacket */ if ((type == USB_ENDPOINT_XFER_BULK) && !ep_comp) { int size = ep->maxpacket_limit; /* min() doesn't work on bitfields with gcc-3.5 */ if (size > 64) size = 64; desc->wMaxPacketSize = cpu_to_le16(size); } ep->address = desc->bEndpointAddress; ep->desc = NULL; ep->comp_desc = NULL; ep->claimed = true; return ep; }

Contributors

PersonTokensPropCommitsCommitProp
Robert Baldyga20971.09%450.00%
David Brownell5619.05%112.50%
Sebastian Andrzej Siewior206.80%112.50%
Tatyana Brokhman82.72%112.50%
Al Viro10.34%112.50%
Total294100.00%8100.00%

EXPORT_SYMBOL_GPL(usb_ep_autoconfig_ss); /** * usb_ep_autoconfig() - choose an endpoint matching the * descriptor * @gadget: The device to which the endpoint must belong. * @desc: Endpoint descriptor, with endpoint direction and transfer mode * initialized. For periodic transfers, the maximum packet * size must also be initialized. This is modified on success. * * By choosing an endpoint to use with the specified descriptor, this * routine simplifies writing gadget drivers that work with multiple * USB device controllers. The endpoint would be passed later to * usb_ep_enable(), along with some descriptor. * * That second descriptor won't always be the same as the first one. * For example, isochronous endpoints can be autoconfigured for high * bandwidth, and then used in several lower bandwidth altsettings. * Also, high and full speed descriptors will be different. * * Be sure to examine and test the results of autoconfiguration on your * hardware. This code may not make the best choices about how to use the * USB controller, and it can't know all the restrictions that may apply. * Some combinations of driver and hardware won't be able to autoconfigure. * * On success, this returns an claimed usb_ep, and modifies the endpoint * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value * is initialized as if the endpoint were used at full speed. To prevent * the endpoint from being returned by a later autoconfig call, claims it * by assigning ep->claimed to true. * * On failure, this returns a null endpoint descriptor. */
struct usb_ep *usb_ep_autoconfig( struct usb_gadget *gadget, struct usb_endpoint_descriptor *desc ) { return usb_ep_autoconfig_ss(gadget, desc, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Tatyana Brokhman27100.00%1100.00%
Total27100.00%1100.00%

EXPORT_SYMBOL_GPL(usb_ep_autoconfig); /** * usb_ep_autoconfig_release - releases endpoint and set it to initial state * @ep: endpoint which should be released * * This function can be used during function bind for endpoints obtained * from usb_ep_autoconfig(). It unclaims endpoint claimed by * usb_ep_autoconfig() to make it available for other functions. Endpoint * which was released is no longer invalid and shouldn't be used in * context of function which released it. */
void usb_ep_autoconfig_release(struct usb_ep *ep) { ep->claimed = false; ep->driver_data = NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Robert Baldyga22100.00%1100.00%
Total22100.00%1100.00%

EXPORT_SYMBOL_GPL(usb_ep_autoconfig_release); /** * usb_ep_autoconfig_reset - reset endpoint autoconfig state * @gadget: device for which autoconfig state will be reset * * Use this for devices where one configuration may need to assign * endpoint resources very differently from the next one. It clears * state such as ep->claimed and the record of assigned endpoints * used by usb_ep_autoconfig(). */
void usb_ep_autoconfig_reset (struct usb_gadget *gadget) { struct usb_ep *ep; list_for_each_entry (ep, &gadget->ep_list, ep_list) { ep->claimed = false; ep->driver_data = NULL; } gadget->in_epnum = 0; gadget->out_epnum = 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Brownell3673.47%125.00%
Robert Baldyga816.33%250.00%
Sebastian Andrzej Siewior510.20%125.00%
Total49100.00%4100.00%

EXPORT_SYMBOL_GPL(usb_ep_autoconfig_reset);

Overall Contributors

PersonTokensPropCommitsCommitProp
Robert Baldyga24856.24%743.75%
David Brownell11325.62%318.75%
Sebastian Andrzej Siewior439.75%318.75%
Tatyana Brokhman357.94%16.25%
Al Viro10.23%16.25%
Klaus Schwarzkopf10.23%16.25%
Total441100.00%16100.00%
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