diff options
Diffstat (limited to 'drivers/usb/gadget/function/f_loopback.c')
-rw-r--r-- | drivers/usb/gadget/function/f_loopback.c | 193 |
1 files changed, 119 insertions, 74 deletions
diff --git a/drivers/usb/gadget/function/f_loopback.c b/drivers/usb/gadget/function/f_loopback.c index 6e2fe63b9267..ddc3aad886b7 100644 --- a/drivers/usb/gadget/function/f_loopback.c +++ b/drivers/usb/gadget/function/f_loopback.c @@ -34,6 +34,9 @@ struct f_loopback { struct usb_ep *in_ep; struct usb_ep *out_ep; + + unsigned qlen; + unsigned buflen; }; static inline struct f_loopback *func_to_loop(struct usb_function *f) @@ -41,13 +44,10 @@ 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, + .bLength = sizeof(loopback_intf), .bDescriptorType = USB_DT_INTERFACE, .bNumEndpoints = 2, @@ -195,12 +195,10 @@ autoconf_fail: 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 = @@ -245,22 +243,38 @@ static void loopback_complete(struct usb_ep *ep, struct usb_request *req) 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; + /* + * We received some data from the host so let's + * queue it so host can read the from our in ep + */ + struct usb_request *in_req = req->context; + + in_req->zero = (req->actual < req->length); + in_req->length = req->actual; + ep = loop->in_ep; + req = in_req; + } else { + /* + * We have just looped back a bunch of data + * to host. Now let's wait for some more data. + */ + req = req->context; + ep = loop->out_ep; } - /* queue the buffer for some later OUT packet */ - req->length = buflen; + /* queue the buffer back to host or for next bunch of data */ status = usb_ep_queue(ep, req, GFP_ATOMIC); - if (status == 0) + if (status == 0) { return; + } else { + ERROR(cdev, "Unable to loop back buffer to %s: %d\n", + ep->name, status); + goto free_req; + } /* "should never get here" */ - /* FALLTHROUGH */ - default: ERROR(cdev, "%s loop complete --> %d, %d/%d\n", ep->name, status, req->actual, req->length); @@ -274,6 +288,10 @@ static void loopback_complete(struct usb_ep *ep, struct usb_request *req) case -ECONNABORTED: /* hardware forced ep reset */ case -ECONNRESET: /* request dequeued */ case -ESHUTDOWN: /* disconnect from host */ +free_req: + usb_ep_free_request(ep == loop->in_ep ? + loop->out_ep : loop->in_ep, + req->context); free_ep_req(ep, req); return; } @@ -290,53 +308,77 @@ static void disable_loopback(struct f_loopback *loop) static inline struct usb_request *lb_alloc_ep_req(struct usb_ep *ep, int len) { - return alloc_ep_req(ep, len, buflen); + struct f_loopback *loop = ep->driver_data; + + return alloc_ep_req(ep, len, loop->buflen); } -static int enable_endpoint(struct usb_composite_dev *cdev, struct f_loopback *loop, - struct usb_ep *ep) +static int alloc_requests(struct usb_composite_dev *cdev, + struct f_loopback *loop) { - 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; + struct usb_request *in_req, *out_req; + int i; + int result = 0; /* * 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. + * we buffer at most 'qlen' transfers; We allocate buffers only + * for out transfer and reuse them in IN transfers to implement + * our loopback functionality */ - for (i = 0; i < qlen && result == 0; i++) { - req = lb_alloc_ep_req(ep, 0); - if (!req) - goto fail1; + for (i = 0; i < loop->qlen && result == 0; i++) { + result = -ENOMEM; + + in_req = usb_ep_alloc_request(loop->in_ep, GFP_ATOMIC); + if (!in_req) + goto fail; + + out_req = lb_alloc_ep_req(loop->out_ep, 0); + if (!out_req) + goto fail_in; + + in_req->complete = loopback_complete; + out_req->complete = loopback_complete; - req->complete = loopback_complete; - result = usb_ep_queue(ep, req, GFP_ATOMIC); + in_req->buf = out_req->buf; + /* length will be set in complete routine */ + in_req->context = out_req; + out_req->context = in_req; + + result = usb_ep_queue(loop->out_ep, out_req, GFP_ATOMIC); if (result) { ERROR(cdev, "%s queue req --> %d\n", - ep->name, result); - goto fail1; + loop->out_ep->name, result); + goto fail_out; } } return 0; -fail1: - usb_ep_disable(ep); +fail_out: + free_ep_req(loop->out_ep, out_req); +fail_in: + usb_ep_free_request(loop->in_ep, in_req); +fail: + return result; +} + +static int enable_endpoint(struct usb_composite_dev *cdev, + struct f_loopback *loop, struct usb_ep *ep) +{ + int result; + + result = config_ep_by_speed(cdev->gadget, &(loop->function), ep); + if (result) + goto out; -fail0: + result = usb_ep_enable(ep); + if (result < 0) + goto out; + ep->driver_data = loop; + result = 0; + +out: return result; } @@ -347,13 +389,24 @@ enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop) result = enable_endpoint(cdev, loop, loop->in_ep); if (result) - return result; + goto out; result = enable_endpoint(cdev, loop, loop->out_ep); if (result) - return result; + goto disable_in; + + result = alloc_requests(cdev, loop); + if (result) + goto disable_out; DBG(cdev, "%s enabled\n", loop->function.name); + return 0; + +disable_out: + usb_ep_disable(loop->out_ep); +disable_in: + usb_ep_disable(loop->in_ep); +out: return result; } @@ -364,8 +417,7 @@ static int loopback_set_alt(struct usb_function *f, struct usb_composite_dev *cdev = f->config->cdev; /* we know alt is zero */ - if (loop->in_ep->driver_data) - disable_loopback(loop); + disable_loopback(loop); return enable_loopback(cdev, loop); } @@ -391,10 +443,10 @@ static struct usb_function *loopback_alloc(struct usb_function_instance *fi) lb_opts->refcnt++; mutex_unlock(&lb_opts->lock); - buflen = lb_opts->bulk_buflen; - qlen = lb_opts->qlen; - if (!qlen) - qlen = 32; + loop->buflen = lb_opts->bulk_buflen; + loop->qlen = lb_opts->qlen; + if (!loop->qlen) + loop->qlen = 32; loop->function.name = "loopback"; loop->function.bind = loopback_bind; @@ -413,9 +465,6 @@ static inline struct f_lb_opts *to_f_lb_opts(struct config_item *item) 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); @@ -425,24 +474,24 @@ static void lb_attr_release(struct config_item *item) 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) +static ssize_t f_lb_opts_qlen_show(struct config_item *item, char *page) { + struct f_lb_opts *opts = to_f_lb_opts(item); int result; mutex_lock(&opts->lock); - result = sprintf(page, "%d", opts->qlen); + result = sprintf(page, "%d\n", opts->qlen); mutex_unlock(&opts->lock); return result; } -static ssize_t f_lb_opts_qlen_store(struct f_lb_opts *opts, +static ssize_t f_lb_opts_qlen_store(struct config_item *item, const char *page, size_t len) { + struct f_lb_opts *opts = to_f_lb_opts(item); int ret; u32 num; @@ -463,25 +512,24 @@ end: 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); +CONFIGFS_ATTR(f_lb_opts_, qlen); -static ssize_t f_lb_opts_bulk_buflen_show(struct f_lb_opts *opts, char *page) +static ssize_t f_lb_opts_bulk_buflen_show(struct config_item *item, char *page) { + struct f_lb_opts *opts = to_f_lb_opts(item); int result; mutex_lock(&opts->lock); - result = sprintf(page, "%d", opts->bulk_buflen); + result = sprintf(page, "%d\n", opts->bulk_buflen); mutex_unlock(&opts->lock); return result; } -static ssize_t f_lb_opts_bulk_buflen_store(struct f_lb_opts *opts, +static ssize_t f_lb_opts_bulk_buflen_store(struct config_item *item, const char *page, size_t len) { + struct f_lb_opts *opts = to_f_lb_opts(item); int ret; u32 num; @@ -502,14 +550,11 @@ end: 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); +CONFIGFS_ATTR(f_lb_opts_, bulk_buflen); static struct configfs_attribute *lb_attrs[] = { - &f_lb_opts_qlen.attr, - &f_lb_opts_bulk_buflen.attr, + &f_lb_opts_attr_qlen, + &f_lb_opts_attr_bulk_buflen, NULL, }; |