/* * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include <linux/kernel.h> #include <linux/init.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> #include "gadget_chips.h" /* we must assign addresses for configurable endpoints (like net2280) */ static __devinitdata unsigned epnum; // #define MANY_ENDPOINTS #ifdef MANY_ENDPOINTS /* more than 15 configurable endpoints */ static __devinitdata unsigned in_epnum; #endif /* * This should work with endpoints from controller drivers sharing the * same endpoint naming convention. By example: * * - ep1, ep2, ... address is fixed, not direction or type * - ep1in, ep2out, ... address and direction are fixed, not type * - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction * - ep1in-bulk, ep2out-iso, ... all three are fixed * - ep-* ... no functionality restrictions * * Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal. * Less common restrictions are implied by gadget_is_*(). * * NOTE: each endpoint is unidirectional, as specified by its USB * descriptor; and isn't specific to a configuration or altsetting. */ static int __devinit ep_matches ( struct usb_gadget *gadget, struct usb_ep *ep, struct usb_endpoint_descriptor *desc ) { u8 type; const char *tmp; u16 max; /* endpoint already claimed? */ if (NULL != ep->driver_data) return 0; /* only support ep0 for portable CONTROL traffic */ type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; if (USB_ENDPOINT_XFER_CONTROL == type) return 0; /* some other naming convention */ if ('e' != ep->name[0]) return 0; /* type-restriction: "-iso", "-bulk", or "-int". * direction-restriction: "in", "out". */ if ('-' != ep->name[2]) { tmp = strrchr (ep->name, '-'); if (tmp) { switch (type) { case USB_ENDPOINT_XFER_INT: /* bulk endpoints handle interrupt transfers, * except the toggle-quirky iso-synch kind */ if ('s' == tmp[2]) // == "-iso" return 0; /* for now, avoid PXA "interrupt-in"; * it's documented as never using DATA1. */ if (gadget_is_pxa (gadget) && 'i' == tmp [1]) return 0; break; case USB_ENDPOINT_XFER_BULK: if ('b' != tmp[1]) // != "-bulk" return 0; break; case USB_ENDPOINT_XFER_ISOC: if ('s' != tmp[2]) // != "-iso" return 0; } } else { tmp = ep->name + strlen (ep->name); } /* direction-restriction: "..in-..", "out-.." */ tmp--; if (!isdigit (*tmp)) { if (desc->bEndpointAddress & USB_DIR_IN) { if ('n' != *tmp) return 0; } else { if ('t' != *tmp) return 0; } } } /* endpoint maxpacket size is an input parameter, except for bulk * where it's an output parameter representing the full speed limit. * the usb spec fixes high speed bulk maxpacket at 512 bytes. */ max = 0x7ff & le16_to_cpu(desc->wMaxPacketSize); switch (type) { case USB_ENDPOINT_XFER_INT: /* INT: limit 64 bytes full speed, 1024 high speed */ if (!gadget->is_dualspeed && max > 64) return 0; /* FALLTHROUGH */ case USB_ENDPOINT_XFER_ISOC: /* ISO: limit 1023 bytes full speed, 1024 high speed */ if (ep->maxpacket < max) return 0; if (!gadget->is_dualspeed && max > 1023) return 0; /* BOTH: "high bandwidth" works only at high speed */ if ((desc->wMaxPacketSize & __constant_cpu_to_le16(3<<11))) { if (!gadget->is_dualspeed) return 0; /* configure your hardware with enough buffering!! */ } break; } /* MATCH!! */ /* report address */ if (isdigit (ep->name [2])) { u8 num = simple_strtol (&ep->name [2], NULL, 10); desc->bEndpointAddress |= num; #ifdef MANY_ENDPOINTS } else if (desc->bEndpointAddress & USB_DIR_IN) { if (++in_epnum > 15) return 0; desc->bEndpointAddress = USB_DIR_IN | in_epnum; #endif } else { if (++epnum > 15) return 0; desc->bEndpointAddress |= epnum; } /* report (variable) full speed bulk maxpacket */ if (USB_ENDPOINT_XFER_BULK == type) { int size = ep->maxpacket; /* min() doesn't work on bitfields with gcc-3.5 */ if (size > 64) size = 64; desc->wMaxPacketSize = cpu_to_le16(size); } return 1; } static struct usb_ep * __devinit find_ep (struct usb_gadget *gadget, const char *name) { struct usb_ep *ep; list_for_each_entry (ep, &gadget->ep_list, ep_list) { if (0 == strcmp (ep->name, name)) return ep; } return NULL; } /** * 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 un-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, claim it * by assigning ep->driver_data to some non-null value. * * On failure, this returns a null endpoint descriptor. */ struct usb_ep * __devinit usb_ep_autoconfig ( struct usb_gadget *gadget, struct usb_endpoint_descriptor *desc ) { struct usb_ep *ep; u8 type; type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; /* First, apply chip-specific "best usage" knowledge. * This might make a good usb_gadget_ops hook ... */ if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) { /* ep-e, ep-f are PIO with only 64 byte fifos */ ep = find_ep (gadget, "ep-e"); if (ep && ep_matches (gadget, ep, desc)) return ep; ep = find_ep (gadget, "ep-f"); if (ep && ep_matches (gadget, ep, desc)) return ep; } else if (gadget_is_goku (gadget)) { if (USB_ENDPOINT_XFER_INT == type) { /* single buffering is enough */ ep = find_ep (gadget, "ep3-bulk"); if (ep && ep_matches (gadget, ep, desc)) return ep; } else if (USB_ENDPOINT_XFER_BULK == type && (USB_DIR_IN & desc->bEndpointAddress)) { /* DMA may be available */ ep = find_ep (gadget, "ep2-bulk"); if (ep && ep_matches (gadget, ep, desc)) return ep; } } else if (gadget_is_sh (gadget) && USB_ENDPOINT_XFER_INT == type) { /* single buffering is enough; maybe 8 byte fifo is too */ ep = find_ep (gadget, "ep3in-bulk"); if (ep && ep_matches (gadget, ep, desc)) return ep; } else if (gadget_is_mq11xx (gadget) && USB_ENDPOINT_XFER_INT == type) { ep = find_ep (gadget, "ep1-bulk"); if (ep && ep_matches (gadget, ep, desc)) return ep; } /* Second, look at endpoints until an unclaimed one looks usable */ list_for_each_entry (ep, &gadget->ep_list, ep_list) { if (ep_matches (gadget, ep, desc)) return ep; } /* Fail */ return NULL; } /** * 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->driver_data and the record of assigned endpoints * used by usb_ep_autoconfig(). */ void __devinit usb_ep_autoconfig_reset (struct usb_gadget *gadget) { struct usb_ep *ep; list_for_each_entry (ep, &gadget->ep_list, ep_list) { ep->driver_data = NULL; } #ifdef MANY_ENDPOINTS in_epnum = 0; #endif epnum = 0; }