Bryan Huntsman | 3f2bc4d | 2011-08-16 17:27:22 -0700 | [diff] [blame] | 1 | /* drivers/usb/function/loopback.c |
| 2 | * |
| 3 | * Simple Loopback Function Device |
| 4 | * |
| 5 | * Copyright (C) 2007 Google, Inc. |
| 6 | * Author: Brian Swetland <swetland@google.com> |
| 7 | * |
| 8 | * This software is licensed under the terms of the GNU General Public |
| 9 | * License version 2, as published by the Free Software Foundation, and |
| 10 | * may be copied, distributed, and modified under those terms. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | */ |
| 18 | |
| 19 | #include <linux/init.h> |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/kernel.h> |
| 22 | |
| 23 | #include "usb_function.h" |
| 24 | |
| 25 | struct loopback_context |
| 26 | { |
| 27 | struct usb_endpoint *out; |
| 28 | struct usb_endpoint *in; |
| 29 | struct usb_request *req_out; |
| 30 | struct usb_request *req_in; |
| 31 | }; |
| 32 | |
| 33 | static struct loopback_context _context; |
| 34 | |
| 35 | static void loopback_bind(struct usb_endpoint **ept, void *_ctxt) |
| 36 | { |
| 37 | struct loopback_context *ctxt = _ctxt; |
| 38 | |
| 39 | ctxt->out = ept[0]; |
| 40 | ctxt->in = ept[1]; |
| 41 | |
| 42 | printk(KERN_INFO "loopback_bind() %p, %p\n", ctxt->out, ctxt->in); |
| 43 | |
| 44 | ctxt->req_out = usb_ept_alloc_req(ctxt->out, 4096); |
| 45 | ctxt->req_in = usb_ept_alloc_req(ctxt->in, 4096); |
| 46 | } |
| 47 | |
| 48 | static void loopback_queue_in(struct loopback_context *ctxt, void *data, unsigned len); |
| 49 | static void loopback_queue_out(struct loopback_context *ctxt); |
| 50 | |
| 51 | static void loopback_in_complete(struct usb_endpoint *ept, struct usb_request *req) |
| 52 | { |
| 53 | struct loopback_context *ctxt = req->context; |
| 54 | printk(KERN_INFO "loopback_out_complete (%d)\n", req->actual); |
| 55 | loopback_queue_out(ctxt); |
| 56 | } |
| 57 | |
| 58 | static void loopback_out_complete(struct usb_endpoint *ept, struct usb_request *req) |
| 59 | { |
| 60 | struct loopback_context *ctxt = req->context; |
| 61 | printk(KERN_INFO "loopback_in_complete (%d)\n", req->actual); |
| 62 | |
| 63 | if (req->status == 0) { |
| 64 | loopback_queue_in(ctxt, req->buf, req->actual); |
| 65 | } else { |
| 66 | loopback_queue_out(ctxt); |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | static void loopback_queue_out(struct loopback_context *ctxt) |
| 71 | { |
| 72 | struct usb_request *req = ctxt->req_out; |
| 73 | |
| 74 | req->complete = loopback_out_complete; |
| 75 | req->context = ctxt; |
| 76 | req->length = 4096; |
| 77 | |
| 78 | usb_ept_queue_xfer(ctxt->out, req); |
| 79 | } |
| 80 | |
| 81 | static void loopback_queue_in(struct loopback_context *ctxt, void *data, unsigned len) |
| 82 | { |
| 83 | struct usb_request *req = ctxt->req_in; |
| 84 | |
| 85 | memcpy(req->buf, data, len); |
| 86 | req->complete = loopback_in_complete; |
| 87 | req->context = ctxt; |
| 88 | req->length = len; |
| 89 | |
| 90 | usb_ept_queue_xfer(ctxt->in, req); |
| 91 | } |
| 92 | |
| 93 | static void loopback_configure(int configured, void *_ctxt) |
| 94 | { |
| 95 | struct loopback_context *ctxt = _ctxt; |
| 96 | printk(KERN_INFO "loopback_configure() %d\n", configured); |
| 97 | |
| 98 | if (configured) { |
| 99 | loopback_queue_out(ctxt); |
| 100 | } else { |
| 101 | /* all pending requests will be canceled */ |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | static struct usb_function usb_func_loopback = { |
| 106 | .bind = loopback_bind, |
| 107 | .configure = loopback_configure, |
| 108 | |
| 109 | .name = "loopback", |
| 110 | .context = &_context, |
| 111 | |
| 112 | .ifc_class = 0xff, |
| 113 | .ifc_subclass = 0xff, |
| 114 | .ifc_protocol = 0xff, |
| 115 | |
| 116 | .ifc_name = "loopback", |
| 117 | |
| 118 | .ifc_ept_count = 2, |
| 119 | .ifc_ept_type = { EPT_BULK_OUT, EPT_BULK_IN }, |
| 120 | }; |
| 121 | |
| 122 | static int __init loopback_init(void) |
| 123 | { |
| 124 | printk(KERN_INFO "loopback_init()\n"); |
| 125 | return usb_function_register(&usb_func_loopback); |
| 126 | } |
| 127 | |
| 128 | module_init(loopback_init); |