--- /dev/null
+/*
+ * 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 <linux/module.h>
+#include <linux/err.h>
+#include <linux/usb/composite.h>
+
+#include "g_zero.h"
+#include "u_f.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;
+static unsigned buflen;
+
+/*-------------------------------------------------------------------------*/
+
+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),
+};
+
+static 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),
+};
+
+static 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 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;
+ int ret;
+
+ /* allocate interface ID(s) */
+ id = usb_interface_id(c, f);
+ if (id < 0)
+ return id;
+ loopback_intf.bInterfaceNumber = id;
+
+ id = usb_string_id(cdev);
+ if (id < 0)
+ return id;
+ strings_loopback[0].id = id;
+ loopback_intf.iInterface = 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 */
+ hs_loop_source_desc.bEndpointAddress =
+ fs_loop_source_desc.bEndpointAddress;
+ hs_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
+
+ /* support super speed hardware */
+ ss_loop_source_desc.bEndpointAddress =
+ fs_loop_source_desc.bEndpointAddress;
+ ss_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
+
+ ret = usb_assign_descriptors(f, fs_loopback_descs, hs_loopback_descs,
+ ss_loopback_descs);
+ if (ret)
+ return ret;
+
+ 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 lb_free_func(struct usb_function *f)
+{
+ struct f_lb_opts *opts;
+
+ opts = container_of(f->fi, struct f_lb_opts, func_inst);
+
+ mutex_lock(&opts->lock);
+ opts->refcnt--;
+ mutex_unlock(&opts->lock);
+
+ usb_free_all_descriptors(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) {
+ req->zero = (req->actual < req->length);
+ req->length = req->actual;
+ }
+
+ /* queue the buffer for some later OUT packet */
+ req->length = buflen;
+ status = usb_ep_queue(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, NULL, NULL);
+ VDBG(cdev, "%s disabled\n", loop->function.name);
+}
+
+static inline struct usb_request *lb_alloc_ep_req(struct usb_ep *ep, int len)
+{
+ return alloc_ep_req(ep, len, buflen);
+}
+
+static int enable_endpoint(struct usb_composite_dev *cdev, struct f_loopback *loop,
+ struct usb_ep *ep)
+{
+ struct usb_request *req;
+ unsigned i;
+ int result;
+
+ /*
+ * one endpoint writes data back IN to the host while another endpoint
+ * just reads OUT packets
+ */
+ result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
+ if (result)
+ goto fail0;
+ result = usb_ep_enable(ep);
+ if (result < 0)
+ goto fail0;
+ 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 = lb_alloc_ep_req(ep, 0);
+ if (!req)
+ goto fail1;
+
+ req->complete = loopback_complete;
+ result = usb_ep_queue(ep, req, GFP_ATOMIC);
+ if (result) {
+ ERROR(cdev, "%s queue req --> %d\n",
+ ep->name, result);
+ goto fail1;
+ }
+ }
+
+ return 0;
+
+fail1:
+ usb_ep_disable(ep);
+
+fail0:
+ return result;
+}
+
+static int
+enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop)
+{
+ int result = 0;
+
+ result = enable_endpoint(cdev, loop, loop->in_ep);
+ if (result)
+ return result;
+
+ result = enable_endpoint(cdev, loop, loop->out_ep);
+ if (result)
+ return result;
+
+ 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 struct usb_function *loopback_alloc(struct usb_function_instance *fi)
+{
+ struct f_loopback *loop;
+ struct f_lb_opts *lb_opts;
+
+ loop = kzalloc(sizeof *loop, GFP_KERNEL);
+ if (!loop)
+ return ERR_PTR(-ENOMEM);
+
+ lb_opts = container_of(fi, struct f_lb_opts, func_inst);
+
+ mutex_lock(&lb_opts->lock);
+ lb_opts->refcnt++;
+ mutex_unlock(&lb_opts->lock);
+
+ buflen = lb_opts->bulk_buflen;
+ qlen = lb_opts->qlen;
+ if (!qlen)
+ qlen = 32;
+
+ loop->function.name = "loopback";
+ loop->function.bind = loopback_bind;
+ loop->function.set_alt = loopback_set_alt;
+ loop->function.disable = loopback_disable;
+ loop->function.strings = loopback_strings;
+
+ loop->function.free_func = lb_free_func;
+
+ return &loop->function;
+}
+
+static inline struct f_lb_opts *to_f_lb_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_lb_opts,
+ func_inst.group);
+}
+
+CONFIGFS_ATTR_STRUCT(f_lb_opts);
+CONFIGFS_ATTR_OPS(f_lb_opts);
+
+static void lb_attr_release(struct config_item *item)
+{
+ struct f_lb_opts *lb_opts = to_f_lb_opts(item);
+
+ usb_put_function_instance(&lb_opts->func_inst);
+}
+
+static struct configfs_item_operations lb_item_ops = {
+ .release = lb_attr_release,
+ .show_attribute = f_lb_opts_attr_show,
+ .store_attribute = f_lb_opts_attr_store,
+};
+
+static ssize_t f_lb_opts_qlen_show(struct f_lb_opts *opts, char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d", opts->qlen);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t f_lb_opts_qlen_store(struct f_lb_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u32 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou32(page, 0, &num);
+ if (ret)
+ goto end;
+
+ opts->qlen = num;
+ ret = len;
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_lb_opts_attribute f_lb_opts_qlen =
+ __CONFIGFS_ATTR(qlen, S_IRUGO | S_IWUSR,
+ f_lb_opts_qlen_show,
+ f_lb_opts_qlen_store);
+
+static ssize_t f_lb_opts_bulk_buflen_show(struct f_lb_opts *opts, char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d", opts->bulk_buflen);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t f_lb_opts_bulk_buflen_store(struct f_lb_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u32 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou32(page, 0, &num);
+ if (ret)
+ goto end;
+
+ opts->bulk_buflen = num;
+ ret = len;
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_lb_opts_attribute f_lb_opts_bulk_buflen =
+ __CONFIGFS_ATTR(buflen, S_IRUGO | S_IWUSR,
+ f_lb_opts_bulk_buflen_show,
+ f_lb_opts_bulk_buflen_store);
+
+static struct configfs_attribute *lb_attrs[] = {
+ &f_lb_opts_qlen.attr,
+ &f_lb_opts_bulk_buflen.attr,
+ NULL,
+};
+
+static struct config_item_type lb_func_type = {
+ .ct_item_ops = &lb_item_ops,
+ .ct_attrs = lb_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static void lb_free_instance(struct usb_function_instance *fi)
+{
+ struct f_lb_opts *lb_opts;
+
+ lb_opts = container_of(fi, struct f_lb_opts, func_inst);
+ kfree(lb_opts);
+}
+
+static struct usb_function_instance *loopback_alloc_instance(void)
+{
+ struct f_lb_opts *lb_opts;
+
+ lb_opts = kzalloc(sizeof(*lb_opts), GFP_KERNEL);
+ if (!lb_opts)
+ return ERR_PTR(-ENOMEM);
+ mutex_init(&lb_opts->lock);
+ lb_opts->func_inst.free_func_inst = lb_free_instance;
+ lb_opts->bulk_buflen = GZERO_BULK_BUFLEN;
+ lb_opts->qlen = GZERO_QLEN;
+
+ config_group_init_type_name(&lb_opts->func_inst.group, "",
+ &lb_func_type);
+
+ return &lb_opts->func_inst;
+}
+DECLARE_USB_FUNCTION(Loopback, loopback_alloc_instance, loopback_alloc);
+
+int __init lb_modinit(void)
+{
+ int ret;
+
+ ret = usb_function_register(&Loopbackusb_func);
+ if (ret)
+ return ret;
+ return ret;
+}
+void __exit lb_modexit(void)
+{
+ usb_function_unregister(&Loopbackusb_func);
+}
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff