599 строки
14 KiB
C
599 строки
14 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* f_loopback.c - USB peripheral loopback configuration driver
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*
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* Copyright (C) 2003-2008 David Brownell
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* Copyright (C) 2008 by Nokia Corporation
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*/
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/* #define VERBOSE_DEBUG */
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/usb/composite.h>
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#include "g_zero.h"
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#include "u_f.h"
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/*
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* LOOPBACK FUNCTION ... a testing vehicle for USB peripherals,
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*
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* This takes messages of various sizes written OUT to a device, and loops
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* them back so they can be read IN from it. It has been used by certain
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* test applications. It supports limited testing of data queueing logic.
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*/
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struct f_loopback {
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struct usb_function function;
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struct usb_ep *in_ep;
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struct usb_ep *out_ep;
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unsigned qlen;
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unsigned buflen;
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};
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static inline struct f_loopback *func_to_loop(struct usb_function *f)
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{
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return container_of(f, struct f_loopback, function);
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}
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/*-------------------------------------------------------------------------*/
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static struct usb_interface_descriptor loopback_intf = {
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.bLength = sizeof(loopback_intf),
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.bDescriptorType = USB_DT_INTERFACE,
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.bNumEndpoints = 2,
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.bInterfaceClass = USB_CLASS_VENDOR_SPEC,
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/* .iInterface = DYNAMIC */
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};
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/* full speed support: */
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static struct usb_endpoint_descriptor fs_loop_source_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = USB_DIR_IN,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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};
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static struct usb_endpoint_descriptor fs_loop_sink_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = USB_DIR_OUT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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};
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static struct usb_descriptor_header *fs_loopback_descs[] = {
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(struct usb_descriptor_header *) &loopback_intf,
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(struct usb_descriptor_header *) &fs_loop_sink_desc,
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(struct usb_descriptor_header *) &fs_loop_source_desc,
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NULL,
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};
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/* high speed support: */
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static struct usb_endpoint_descriptor hs_loop_source_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(512),
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};
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static struct usb_endpoint_descriptor hs_loop_sink_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(512),
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};
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static struct usb_descriptor_header *hs_loopback_descs[] = {
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(struct usb_descriptor_header *) &loopback_intf,
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(struct usb_descriptor_header *) &hs_loop_source_desc,
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(struct usb_descriptor_header *) &hs_loop_sink_desc,
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NULL,
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};
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/* super speed support: */
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static struct usb_endpoint_descriptor ss_loop_source_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(1024),
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};
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static struct usb_ss_ep_comp_descriptor ss_loop_source_comp_desc = {
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.bLength = USB_DT_SS_EP_COMP_SIZE,
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.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
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.bMaxBurst = 0,
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.bmAttributes = 0,
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.wBytesPerInterval = 0,
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};
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static struct usb_endpoint_descriptor ss_loop_sink_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(1024),
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};
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static struct usb_ss_ep_comp_descriptor ss_loop_sink_comp_desc = {
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.bLength = USB_DT_SS_EP_COMP_SIZE,
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.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
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.bMaxBurst = 0,
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.bmAttributes = 0,
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.wBytesPerInterval = 0,
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};
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static struct usb_descriptor_header *ss_loopback_descs[] = {
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(struct usb_descriptor_header *) &loopback_intf,
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(struct usb_descriptor_header *) &ss_loop_source_desc,
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(struct usb_descriptor_header *) &ss_loop_source_comp_desc,
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(struct usb_descriptor_header *) &ss_loop_sink_desc,
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(struct usb_descriptor_header *) &ss_loop_sink_comp_desc,
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NULL,
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};
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/* function-specific strings: */
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static struct usb_string strings_loopback[] = {
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[0].s = "loop input to output",
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{ } /* end of list */
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};
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static struct usb_gadget_strings stringtab_loop = {
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.language = 0x0409, /* en-us */
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.strings = strings_loopback,
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};
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static struct usb_gadget_strings *loopback_strings[] = {
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&stringtab_loop,
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NULL,
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};
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/*-------------------------------------------------------------------------*/
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static int loopback_bind(struct usb_configuration *c, struct usb_function *f)
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{
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struct usb_composite_dev *cdev = c->cdev;
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struct f_loopback *loop = func_to_loop(f);
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int id;
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int ret;
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/* allocate interface ID(s) */
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id = usb_interface_id(c, f);
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if (id < 0)
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return id;
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loopback_intf.bInterfaceNumber = id;
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id = usb_string_id(cdev);
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if (id < 0)
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return id;
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strings_loopback[0].id = id;
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loopback_intf.iInterface = id;
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/* allocate endpoints */
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loop->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_source_desc);
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if (!loop->in_ep) {
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autoconf_fail:
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ERROR(cdev, "%s: can't autoconfigure on %s\n",
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f->name, cdev->gadget->name);
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return -ENODEV;
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}
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loop->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_sink_desc);
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if (!loop->out_ep)
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goto autoconf_fail;
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/* support high speed hardware */
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hs_loop_source_desc.bEndpointAddress =
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fs_loop_source_desc.bEndpointAddress;
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hs_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
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/* support super speed hardware */
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ss_loop_source_desc.bEndpointAddress =
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fs_loop_source_desc.bEndpointAddress;
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ss_loop_sink_desc.bEndpointAddress = fs_loop_sink_desc.bEndpointAddress;
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ret = usb_assign_descriptors(f, fs_loopback_descs, hs_loopback_descs,
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ss_loopback_descs, NULL);
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if (ret)
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return ret;
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DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
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(gadget_is_superspeed(c->cdev->gadget) ? "super" :
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(gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")),
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f->name, loop->in_ep->name, loop->out_ep->name);
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return 0;
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}
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static void lb_free_func(struct usb_function *f)
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{
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struct f_lb_opts *opts;
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opts = container_of(f->fi, struct f_lb_opts, func_inst);
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mutex_lock(&opts->lock);
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opts->refcnt--;
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mutex_unlock(&opts->lock);
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usb_free_all_descriptors(f);
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kfree(func_to_loop(f));
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}
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static void loopback_complete(struct usb_ep *ep, struct usb_request *req)
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{
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struct f_loopback *loop = ep->driver_data;
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struct usb_composite_dev *cdev = loop->function.config->cdev;
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int status = req->status;
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switch (status) {
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case 0: /* normal completion? */
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if (ep == loop->out_ep) {
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/*
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* We received some data from the host so let's
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* queue it so host can read the from our in ep
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*/
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struct usb_request *in_req = req->context;
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in_req->zero = (req->actual < req->length);
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in_req->length = req->actual;
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ep = loop->in_ep;
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req = in_req;
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} else {
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/*
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* We have just looped back a bunch of data
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* to host. Now let's wait for some more data.
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*/
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req = req->context;
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ep = loop->out_ep;
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}
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/* queue the buffer back to host or for next bunch of data */
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status = usb_ep_queue(ep, req, GFP_ATOMIC);
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if (status == 0) {
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return;
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} else {
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ERROR(cdev, "Unable to loop back buffer to %s: %d\n",
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ep->name, status);
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goto free_req;
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}
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/* "should never get here" */
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default:
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ERROR(cdev, "%s loop complete --> %d, %d/%d\n", ep->name,
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status, req->actual, req->length);
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/* FALLTHROUGH */
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/* NOTE: since this driver doesn't maintain an explicit record
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* of requests it submitted (just maintains qlen count), we
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* rely on the hardware driver to clean up on disconnect or
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* endpoint disable.
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*/
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case -ECONNABORTED: /* hardware forced ep reset */
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case -ECONNRESET: /* request dequeued */
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case -ESHUTDOWN: /* disconnect from host */
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free_req:
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usb_ep_free_request(ep == loop->in_ep ?
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loop->out_ep : loop->in_ep,
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req->context);
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free_ep_req(ep, req);
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return;
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}
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}
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static void disable_loopback(struct f_loopback *loop)
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{
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struct usb_composite_dev *cdev;
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cdev = loop->function.config->cdev;
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disable_endpoints(cdev, loop->in_ep, loop->out_ep, NULL, NULL);
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VDBG(cdev, "%s disabled\n", loop->function.name);
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}
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static inline struct usb_request *lb_alloc_ep_req(struct usb_ep *ep, int len)
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{
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return alloc_ep_req(ep, len);
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}
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static int alloc_requests(struct usb_composite_dev *cdev,
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struct f_loopback *loop)
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{
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struct usb_request *in_req, *out_req;
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int i;
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int result = 0;
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/*
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* allocate a bunch of read buffers and queue them all at once.
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* we buffer at most 'qlen' transfers; We allocate buffers only
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* for out transfer and reuse them in IN transfers to implement
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* our loopback functionality
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*/
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for (i = 0; i < loop->qlen && result == 0; i++) {
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result = -ENOMEM;
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in_req = usb_ep_alloc_request(loop->in_ep, GFP_ATOMIC);
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if (!in_req)
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goto fail;
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out_req = lb_alloc_ep_req(loop->out_ep, loop->buflen);
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if (!out_req)
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goto fail_in;
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in_req->complete = loopback_complete;
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out_req->complete = loopback_complete;
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in_req->buf = out_req->buf;
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/* length will be set in complete routine */
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in_req->context = out_req;
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out_req->context = in_req;
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result = usb_ep_queue(loop->out_ep, out_req, GFP_ATOMIC);
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if (result) {
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ERROR(cdev, "%s queue req --> %d\n",
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loop->out_ep->name, result);
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goto fail_out;
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}
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}
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return 0;
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fail_out:
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free_ep_req(loop->out_ep, out_req);
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fail_in:
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usb_ep_free_request(loop->in_ep, in_req);
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fail:
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return result;
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}
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static int enable_endpoint(struct usb_composite_dev *cdev,
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struct f_loopback *loop, struct usb_ep *ep)
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{
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int result;
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result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
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if (result)
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goto out;
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result = usb_ep_enable(ep);
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if (result < 0)
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goto out;
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ep->driver_data = loop;
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result = 0;
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out:
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return result;
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}
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static int
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enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop)
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{
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int result = 0;
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result = enable_endpoint(cdev, loop, loop->in_ep);
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if (result)
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goto out;
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result = enable_endpoint(cdev, loop, loop->out_ep);
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if (result)
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goto disable_in;
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result = alloc_requests(cdev, loop);
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if (result)
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goto disable_out;
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DBG(cdev, "%s enabled\n", loop->function.name);
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return 0;
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disable_out:
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usb_ep_disable(loop->out_ep);
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disable_in:
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usb_ep_disable(loop->in_ep);
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out:
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return result;
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}
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static int loopback_set_alt(struct usb_function *f,
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unsigned intf, unsigned alt)
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{
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struct f_loopback *loop = func_to_loop(f);
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struct usb_composite_dev *cdev = f->config->cdev;
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/* we know alt is zero */
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disable_loopback(loop);
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return enable_loopback(cdev, loop);
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}
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static void loopback_disable(struct usb_function *f)
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{
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struct f_loopback *loop = func_to_loop(f);
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disable_loopback(loop);
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}
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static struct usb_function *loopback_alloc(struct usb_function_instance *fi)
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{
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struct f_loopback *loop;
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struct f_lb_opts *lb_opts;
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loop = kzalloc(sizeof *loop, GFP_KERNEL);
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if (!loop)
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return ERR_PTR(-ENOMEM);
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lb_opts = container_of(fi, struct f_lb_opts, func_inst);
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mutex_lock(&lb_opts->lock);
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lb_opts->refcnt++;
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mutex_unlock(&lb_opts->lock);
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loop->buflen = lb_opts->bulk_buflen;
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loop->qlen = lb_opts->qlen;
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if (!loop->qlen)
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loop->qlen = 32;
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loop->function.name = "loopback";
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loop->function.bind = loopback_bind;
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loop->function.set_alt = loopback_set_alt;
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loop->function.disable = loopback_disable;
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loop->function.strings = loopback_strings;
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loop->function.free_func = lb_free_func;
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return &loop->function;
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}
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static inline struct f_lb_opts *to_f_lb_opts(struct config_item *item)
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{
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return container_of(to_config_group(item), struct f_lb_opts,
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func_inst.group);
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}
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static void lb_attr_release(struct config_item *item)
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{
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struct f_lb_opts *lb_opts = to_f_lb_opts(item);
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usb_put_function_instance(&lb_opts->func_inst);
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}
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static struct configfs_item_operations lb_item_ops = {
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.release = lb_attr_release,
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};
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static ssize_t f_lb_opts_qlen_show(struct config_item *item, char *page)
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{
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struct f_lb_opts *opts = to_f_lb_opts(item);
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int result;
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mutex_lock(&opts->lock);
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result = sprintf(page, "%d\n", opts->qlen);
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mutex_unlock(&opts->lock);
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return result;
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}
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static ssize_t f_lb_opts_qlen_store(struct config_item *item,
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const char *page, size_t len)
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{
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struct f_lb_opts *opts = to_f_lb_opts(item);
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int ret;
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u32 num;
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mutex_lock(&opts->lock);
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if (opts->refcnt) {
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ret = -EBUSY;
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goto end;
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}
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ret = kstrtou32(page, 0, &num);
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if (ret)
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goto end;
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opts->qlen = num;
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ret = len;
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end:
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mutex_unlock(&opts->lock);
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return ret;
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}
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CONFIGFS_ATTR(f_lb_opts_, qlen);
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static ssize_t f_lb_opts_bulk_buflen_show(struct config_item *item, char *page)
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{
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struct f_lb_opts *opts = to_f_lb_opts(item);
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int result;
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mutex_lock(&opts->lock);
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result = sprintf(page, "%d\n", opts->bulk_buflen);
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mutex_unlock(&opts->lock);
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return result;
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}
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static ssize_t f_lb_opts_bulk_buflen_store(struct config_item *item,
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const char *page, size_t len)
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{
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struct f_lb_opts *opts = to_f_lb_opts(item);
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int ret;
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u32 num;
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mutex_lock(&opts->lock);
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if (opts->refcnt) {
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ret = -EBUSY;
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goto end;
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}
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ret = kstrtou32(page, 0, &num);
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if (ret)
|
|
goto end;
|
|
|
|
opts->bulk_buflen = num;
|
|
ret = len;
|
|
end:
|
|
mutex_unlock(&opts->lock);
|
|
return ret;
|
|
}
|
|
|
|
CONFIGFS_ATTR(f_lb_opts_, bulk_buflen);
|
|
|
|
static struct configfs_attribute *lb_attrs[] = {
|
|
&f_lb_opts_attr_qlen,
|
|
&f_lb_opts_attr_bulk_buflen,
|
|
NULL,
|
|
};
|
|
|
|
static const 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)
|
|
{
|
|
return usb_function_register(&Loopbackusb_func);
|
|
}
|
|
|
|
void __exit lb_modexit(void)
|
|
{
|
|
usb_function_unregister(&Loopbackusb_func);
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|