/* * f_loopback.c - USB peripheral loopback configuration driver * * Copyright (C) 2003-2008 David Brownell * Copyright (C) 2008 by Nokia Corporation * * 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. */ /* #define VERBOSE_DEBUG */ #include <linux/slab.h> #include <linux/kernel.h> #include <linux/device.h> #include "g_zero.h" #include "gadget_chips.h" /* * LOOPBACK FUNCTION ... a testing vehicle for USB peripherals, * * This takes messages of various sizes written OUT to a device, and loops * them back so they can be read IN from it. It has been used by certain * test applications. It supports limited testing of data queueing logic. * * * This is currently packaged as a configuration driver, which can't be * combined with other functions to make composite devices. However, it * can be combined with other independent configurations. */ struct f_loopback { struct usb_function function; struct usb_ep *in_ep; struct usb_ep *out_ep; }; static inline struct f_loopback *func_to_loop(struct usb_function *f) { return container_of(f, struct f_loopback, function); } static unsigned qlen = 32; module_param(qlen, uint, 0); MODULE_PARM_DESC(qlenn, "depth of loopback queue"); /*-------------------------------------------------------------------------*/ static struct usb_interface_descriptor loopback_intf = { .bLength = sizeof loopback_intf, .bDescriptorType = USB_DT_INTERFACE, .bNumEndpoints = 2, .bInterfaceClass = USB_CLASS_VENDOR_SPEC, /* .iInterface = DYNAMIC */ }; /* full speed support: */ static struct usb_endpoint_descriptor fs_loop_source_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_BULK, }; static struct usb_endpoint_descriptor fs_loop_sink_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .bmAttributes = USB_ENDPOINT_XFER_BULK, }; static struct usb_descriptor_header *fs_loopback_descs[] = { (struct usb_descriptor_header *) &loopback_intf, (struct usb_descriptor_header *) &fs_loop_sink_desc, (struct usb_descriptor_header *) &fs_loop_source_desc, NULL, }; /* high speed support: */ static struct usb_endpoint_descriptor hs_loop_source_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(512), }; static struct usb_endpoint_descriptor hs_loop_sink_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(512), }; static struct usb_descriptor_header *hs_loopback_descs[] = { (struct usb_descriptor_header *) &loopback_intf, (struct usb_descriptor_header *) &hs_loop_source_desc, (struct usb_descriptor_header *) &hs_loop_sink_desc, NULL, }; /* super speed support: */ static struct usb_endpoint_descriptor ss_loop_source_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(1024), }; struct usb_ss_ep_comp_descriptor ss_loop_source_comp_desc = { .bLength = USB_DT_SS_EP_COMP_SIZE, .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, .bMaxBurst = 0, .bmAttributes = 0, .wBytesPerInterval = 0, }; static struct usb_endpoint_descriptor ss_loop_sink_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(1024), }; struct usb_ss_ep_comp_descriptor ss_loop_sink_comp_desc = { .bLength = USB_DT_SS_EP_COMP_SIZE, .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, .bMaxBurst = 0, .bmAttributes = 0, .wBytesPerInterval = 0, }; static struct usb_descriptor_header *ss_loopback_descs[] = { (struct usb_descriptor_header *) &loopback_intf, (struct usb_descriptor_header *) &ss_loop_source_desc, (struct usb_descriptor_header *) &ss_loop_source_comp_desc, (struct usb_descriptor_header *) &ss_loop_sink_desc, (struct usb_descriptor_header *) &ss_loop_sink_comp_desc, NULL, }; /* function-specific strings: */ static struct usb_string strings_loopback[] = { [0].s = "loop input to output", { } /* end of list */ }; static struct usb_gadget_strings stringtab_loop = { .language = 0x0409, /* en-us */ .strings = strings_loopback, }; static struct usb_gadget_strings *loopback_strings[] = { &stringtab_loop, NULL, }; /*-------------------------------------------------------------------------*/ static int __init loopback_bind(struct usb_configuration *c, struct usb_function *f) { struct usb_composite_dev *cdev = c->cdev; struct f_loopback *loop = func_to_loop(f); int id; /* allocate interface ID(s) */ id = usb_interface_id(c, f); if (id < 0) return id; loopback_intf.bInterfaceNumber = id; /* allocate endpoints */ loop->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_source_desc); if (!loop->in_ep) { autoconf_fail: ERROR(cdev, "%s: can't autoconfigure on %s\n", f->name, cdev->gadget->name); return -ENODEV; } loop->in_ep->driver_data = cdev; /* claim */ loop->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_sink_desc); if (!loop->out_ep) goto autoconf_fail; loop->out_ep->driver_data = cdev; /* claim */ /* support high speed hardware */ if (gadget_is_dualspeed(c->cdev->gadget)) { hs_loop_source_desc.bEndpointAddress = fs_loop_source_desc.bEndpointAddress; hs_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress; f->hs_descriptors = hs_loopback_descs; } /* support super speed hardware */ if (gadget_is_superspeed(c->cdev->gadget)) { ss_loop_source_desc.bEndpointAddress = fs_loop_source_desc.bEndpointAddress; ss_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress; f->ss_descriptors = ss_loopback_descs; } DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n", (gadget_is_superspeed(c->cdev->gadget) ? "super" : (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")), f->name, loop->in_ep->name, loop->out_ep->name); return 0; } static void loopback_unbind(struct usb_configuration *c, struct usb_function *f) { kfree(func_to_loop(f)); } static void loopback_complete(struct usb_ep *ep, struct usb_request *req) { struct f_loopback *loop = ep->driver_data; struct usb_composite_dev *cdev = loop->function.config->cdev; int status = req->status; switch (status) { case 0: /* normal completion? */ if (ep == loop->out_ep) { /* loop this OUT packet back IN to the host */ req->zero = (req->actual < req->length); req->length = req->actual; status = usb_ep_queue(loop->in_ep, req, GFP_ATOMIC); if (status == 0) return; /* "should never get here" */ ERROR(cdev, "can't loop %s to %s: %d\n", ep->name, loop->in_ep->name, status); } /* queue the buffer for some later OUT packet */ req->length = buflen; status = usb_ep_queue(loop->out_ep, req, GFP_ATOMIC); if (status == 0) return; /* "should never get here" */ /* FALLTHROUGH */ default: ERROR(cdev, "%s loop complete --> %d, %d/%d\n", ep->name, status, req->actual, req->length); /* FALLTHROUGH */ /* NOTE: since this driver doesn't maintain an explicit record * of requests it submitted (just maintains qlen count), we * rely on the hardware driver to clean up on disconnect or * endpoint disable. */ case -ECONNABORTED: /* hardware forced ep reset */ case -ECONNRESET: /* request dequeued */ case -ESHUTDOWN: /* disconnect from host */ free_ep_req(ep, req); return; } } static void disable_loopback(struct f_loopback *loop) { struct usb_composite_dev *cdev; cdev = loop->function.config->cdev; disable_endpoints(cdev, loop->in_ep, loop->out_ep); VDBG(cdev, "%s disabled\n", loop->function.name); } static int enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop) { int result = 0; struct usb_ep *ep; struct usb_request *req; unsigned i; /* one endpoint writes data back IN to the host */ ep = loop->in_ep; result = config_ep_by_speed(cdev->gadget, &(loop->function), ep); if (result) return result; result = usb_ep_enable(ep); if (result < 0) return result; ep->driver_data = loop; /* one endpoint just reads OUT packets */ ep = loop->out_ep; result = config_ep_by_speed(cdev->gadget, &(loop->function), ep); if (result) goto fail0; result = usb_ep_enable(ep); if (result < 0) { fail0: ep = loop->in_ep; usb_ep_disable(ep); ep->driver_data = NULL; return result; } ep->driver_data = loop; /* allocate a bunch of read buffers and queue them all at once. * we buffer at most 'qlen' transfers; fewer if any need more * than 'buflen' bytes each. */ for (i = 0; i < qlen && result == 0; i++) { req = alloc_ep_req(ep); if (req) { req->complete = loopback_complete; result = usb_ep_queue(ep, req, GFP_ATOMIC); if (result) ERROR(cdev, "%s queue req --> %d\n", ep->name, result); } else { usb_ep_disable(ep); ep->driver_data = NULL; result = -ENOMEM; goto fail0; } } DBG(cdev, "%s enabled\n", loop->function.name); return result; } static int loopback_set_alt(struct usb_function *f, unsigned intf, unsigned alt) { struct f_loopback *loop = func_to_loop(f); struct usb_composite_dev *cdev = f->config->cdev; /* we know alt is zero */ if (loop->in_ep->driver_data) disable_loopback(loop); return enable_loopback(cdev, loop); } static void loopback_disable(struct usb_function *f) { struct f_loopback *loop = func_to_loop(f); disable_loopback(loop); } /*-------------------------------------------------------------------------*/ static int __init loopback_bind_config(struct usb_configuration *c) { struct f_loopback *loop; int status; loop = kzalloc(sizeof *loop, GFP_KERNEL); if (!loop) return -ENOMEM; loop->function.name = "loopback"; loop->function.descriptors = fs_loopback_descs; loop->function.bind = loopback_bind; loop->function.unbind = loopback_unbind; loop->function.set_alt = loopback_set_alt; loop->function.disable = loopback_disable; status = usb_add_function(c, &loop->function); if (status) kfree(loop); return status; } static struct usb_configuration loopback_driver = { .label = "loopback", .strings = loopback_strings, .bConfigurationValue = 2, .bmAttributes = USB_CONFIG_ATT_SELFPOWER, /* .iConfiguration = DYNAMIC */ }; /** * loopback_add - add a loopback testing configuration to a device * @cdev: the device to support the loopback configuration */ int __init loopback_add(struct usb_composite_dev *cdev, bool autoresume) { int id; /* allocate string ID(s) */ id = usb_string_id(cdev); if (id < 0) return id; strings_loopback[0].id = id; loopback_intf.iInterface = id; loopback_driver.iConfiguration = id; /* support autoresume for remote wakeup testing */ if (autoresume) sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP; /* support OTG systems */ if (gadget_is_otg(cdev->gadget)) { loopback_driver.descriptors = otg_desc; loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP; } return usb_add_config(cdev, &loopback_driver, loopback_bind_config); }