| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * dbgp.c -- EHCI Debug Port device gadget |
| * |
| * Copyright (C) 2010 Stephane Duverger |
| * |
| * Released under the GPLv2. |
| */ |
| |
| /* verbose messages */ |
| #include <linux/kernel.h> |
| #include <linux/device.h> |
| #include <linux/module.h> |
| #include <linux/usb/ch9.h> |
| #include <linux/usb/gadget.h> |
| |
| #include "u_serial.h" |
| |
| #define DRIVER_VENDOR_ID 0x0525 /* NetChip */ |
| #define DRIVER_PRODUCT_ID 0xc0de /* undefined */ |
| |
| #define USB_DEBUG_MAX_PACKET_SIZE 8 |
| #define DBGP_REQ_EP0_LEN 128 |
| #define DBGP_REQ_LEN 512 |
| |
| static struct dbgp { |
| struct usb_gadget *gadget; |
| struct usb_request *req; |
| struct usb_ep *i_ep; |
| struct usb_ep *o_ep; |
| #ifdef CONFIG_USB_G_DBGP_SERIAL |
| struct gserial *serial; |
| #endif |
| } dbgp; |
| |
| static struct usb_device_descriptor device_desc = { |
| .bLength = sizeof device_desc, |
| .bDescriptorType = USB_DT_DEVICE, |
| .bcdUSB = cpu_to_le16(0x0200), |
| .bDeviceClass = USB_CLASS_VENDOR_SPEC, |
| .idVendor = cpu_to_le16(DRIVER_VENDOR_ID), |
| .idProduct = cpu_to_le16(DRIVER_PRODUCT_ID), |
| .bNumConfigurations = 1, |
| }; |
| |
| static struct usb_debug_descriptor dbg_desc = { |
| .bLength = sizeof dbg_desc, |
| .bDescriptorType = USB_DT_DEBUG, |
| }; |
| |
| static struct usb_endpoint_descriptor i_desc = { |
| .bLength = USB_DT_ENDPOINT_SIZE, |
| .bDescriptorType = USB_DT_ENDPOINT, |
| .bmAttributes = USB_ENDPOINT_XFER_BULK, |
| .bEndpointAddress = USB_DIR_IN, |
| }; |
| |
| static struct usb_endpoint_descriptor o_desc = { |
| .bLength = USB_DT_ENDPOINT_SIZE, |
| .bDescriptorType = USB_DT_ENDPOINT, |
| .bmAttributes = USB_ENDPOINT_XFER_BULK, |
| .bEndpointAddress = USB_DIR_OUT, |
| }; |
| |
| #ifdef CONFIG_USB_G_DBGP_PRINTK |
| static int dbgp_consume(char *buf, unsigned len) |
| { |
| char c; |
| |
| if (!len) |
| return 0; |
| |
| c = buf[len-1]; |
| if (c != 0) |
| buf[len-1] = 0; |
| |
| printk(KERN_NOTICE "%s%c", buf, c); |
| return 0; |
| } |
| |
| static void __disable_ep(struct usb_ep *ep) |
| { |
| usb_ep_disable(ep); |
| } |
| |
| static void dbgp_disable_ep(void) |
| { |
| __disable_ep(dbgp.i_ep); |
| __disable_ep(dbgp.o_ep); |
| } |
| |
| static void dbgp_complete(struct usb_ep *ep, struct usb_request *req) |
| { |
| int stp; |
| int err = 0; |
| int status = req->status; |
| |
| if (ep == dbgp.i_ep) { |
| stp = 1; |
| goto fail; |
| } |
| |
| if (status != 0) { |
| stp = 2; |
| goto release_req; |
| } |
| |
| dbgp_consume(req->buf, req->actual); |
| |
| req->length = DBGP_REQ_LEN; |
| err = usb_ep_queue(ep, req, GFP_ATOMIC); |
| if (err < 0) { |
| stp = 3; |
| goto release_req; |
| } |
| |
| return; |
| |
| release_req: |
| kfree(req->buf); |
| usb_ep_free_request(dbgp.o_ep, req); |
| dbgp_disable_ep(); |
| fail: |
| dev_dbg(&dbgp.gadget->dev, |
| "complete: failure (%d:%d) ==> %d\n", stp, err, status); |
| } |
| |
| static int dbgp_enable_ep_req(struct usb_ep *ep) |
| { |
| int err, stp; |
| struct usb_request *req; |
| |
| req = usb_ep_alloc_request(ep, GFP_KERNEL); |
| if (!req) { |
| err = -ENOMEM; |
| stp = 1; |
| goto fail_1; |
| } |
| |
| req->buf = kzalloc(DBGP_REQ_LEN, GFP_KERNEL); |
| if (!req->buf) { |
| err = -ENOMEM; |
| stp = 2; |
| goto fail_2; |
| } |
| |
| req->complete = dbgp_complete; |
| req->length = DBGP_REQ_LEN; |
| err = usb_ep_queue(ep, req, GFP_ATOMIC); |
| if (err < 0) { |
| stp = 3; |
| goto fail_3; |
| } |
| |
| return 0; |
| |
| fail_3: |
| kfree(req->buf); |
| fail_2: |
| usb_ep_free_request(dbgp.o_ep, req); |
| fail_1: |
| dev_dbg(&dbgp.gadget->dev, |
| "enable ep req: failure (%d:%d)\n", stp, err); |
| return err; |
| } |
| |
| static int __enable_ep(struct usb_ep *ep, struct usb_endpoint_descriptor *desc) |
| { |
| int err; |
| ep->desc = desc; |
| err = usb_ep_enable(ep); |
| return err; |
| } |
| |
| static int dbgp_enable_ep(void) |
| { |
| int err, stp; |
| |
| err = __enable_ep(dbgp.i_ep, &i_desc); |
| if (err < 0) { |
| stp = 1; |
| goto fail_1; |
| } |
| |
| err = __enable_ep(dbgp.o_ep, &o_desc); |
| if (err < 0) { |
| stp = 2; |
| goto fail_2; |
| } |
| |
| err = dbgp_enable_ep_req(dbgp.o_ep); |
| if (err < 0) { |
| stp = 3; |
| goto fail_3; |
| } |
| |
| return 0; |
| |
| fail_3: |
| __disable_ep(dbgp.o_ep); |
| fail_2: |
| __disable_ep(dbgp.i_ep); |
| fail_1: |
| dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err); |
| return err; |
| } |
| #endif |
| |
| static void dbgp_disconnect(struct usb_gadget *gadget) |
| { |
| #ifdef CONFIG_USB_G_DBGP_PRINTK |
| dbgp_disable_ep(); |
| #else |
| gserial_disconnect(dbgp.serial); |
| #endif |
| } |
| |
| static void dbgp_unbind(struct usb_gadget *gadget) |
| { |
| #ifdef CONFIG_USB_G_DBGP_SERIAL |
| kfree(dbgp.serial); |
| dbgp.serial = NULL; |
| #endif |
| if (dbgp.req) { |
| kfree(dbgp.req->buf); |
| usb_ep_free_request(gadget->ep0, dbgp.req); |
| dbgp.req = NULL; |
| } |
| } |
| |
| #ifdef CONFIG_USB_G_DBGP_SERIAL |
| static unsigned char tty_line; |
| #endif |
| |
| static int dbgp_configure_endpoints(struct usb_gadget *gadget) |
| { |
| int stp; |
| |
| usb_ep_autoconfig_reset(gadget); |
| |
| dbgp.i_ep = usb_ep_autoconfig(gadget, &i_desc); |
| if (!dbgp.i_ep) { |
| stp = 1; |
| goto fail_1; |
| } |
| |
| i_desc.wMaxPacketSize = |
| cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE); |
| |
| dbgp.o_ep = usb_ep_autoconfig(gadget, &o_desc); |
| if (!dbgp.o_ep) { |
| stp = 2; |
| goto fail_1; |
| } |
| |
| o_desc.wMaxPacketSize = |
| cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE); |
| |
| dbg_desc.bDebugInEndpoint = i_desc.bEndpointAddress; |
| dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress; |
| |
| #ifdef CONFIG_USB_G_DBGP_SERIAL |
| dbgp.serial->in = dbgp.i_ep; |
| dbgp.serial->out = dbgp.o_ep; |
| |
| dbgp.serial->in->desc = &i_desc; |
| dbgp.serial->out->desc = &o_desc; |
| #endif |
| |
| return 0; |
| |
| fail_1: |
| dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp); |
| return -ENODEV; |
| } |
| |
| static int dbgp_bind(struct usb_gadget *gadget, |
| struct usb_gadget_driver *driver) |
| { |
| int err, stp; |
| |
| dbgp.gadget = gadget; |
| |
| dbgp.req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL); |
| if (!dbgp.req) { |
| err = -ENOMEM; |
| stp = 1; |
| goto fail; |
| } |
| |
| dbgp.req->buf = kmalloc(DBGP_REQ_EP0_LEN, GFP_KERNEL); |
| if (!dbgp.req->buf) { |
| err = -ENOMEM; |
| stp = 2; |
| goto fail; |
| } |
| |
| dbgp.req->length = DBGP_REQ_EP0_LEN; |
| |
| #ifdef CONFIG_USB_G_DBGP_SERIAL |
| dbgp.serial = kzalloc(sizeof(struct gserial), GFP_KERNEL); |
| if (!dbgp.serial) { |
| stp = 3; |
| err = -ENOMEM; |
| goto fail; |
| } |
| |
| if (gserial_alloc_line(&tty_line)) { |
| stp = 4; |
| err = -ENODEV; |
| goto fail; |
| } |
| #endif |
| |
| err = dbgp_configure_endpoints(gadget); |
| if (err < 0) { |
| stp = 5; |
| goto fail; |
| } |
| |
| dev_dbg(&dbgp.gadget->dev, "bind: success\n"); |
| return 0; |
| |
| fail: |
| dev_dbg(&gadget->dev, "bind: failure (%d:%d)\n", stp, err); |
| dbgp_unbind(gadget); |
| return err; |
| } |
| |
| static void dbgp_setup_complete(struct usb_ep *ep, |
| struct usb_request *req) |
| { |
| dev_dbg(&dbgp.gadget->dev, "setup complete: %d, %d/%d\n", |
| req->status, req->actual, req->length); |
| } |
| |
| static int dbgp_setup(struct usb_gadget *gadget, |
| const struct usb_ctrlrequest *ctrl) |
| { |
| struct usb_request *req = dbgp.req; |
| u8 request = ctrl->bRequest; |
| u16 value = le16_to_cpu(ctrl->wValue); |
| u16 length = le16_to_cpu(ctrl->wLength); |
| int err = -EOPNOTSUPP; |
| void *data = NULL; |
| u16 len = 0; |
| |
| if (length > DBGP_REQ_LEN) { |
| if (ctrl->bRequestType & USB_DIR_IN) { |
| /* Cast away the const, we are going to overwrite on purpose. */ |
| __le16 *temp = (__le16 *)&ctrl->wLength; |
| |
| *temp = cpu_to_le16(DBGP_REQ_LEN); |
| length = DBGP_REQ_LEN; |
| } else { |
| return err; |
| } |
| } |
| |
| |
| if (request == USB_REQ_GET_DESCRIPTOR) { |
| switch (value>>8) { |
| case USB_DT_DEVICE: |
| dev_dbg(&dbgp.gadget->dev, "setup: desc device\n"); |
| len = sizeof device_desc; |
| data = &device_desc; |
| device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket; |
| break; |
| case USB_DT_DEBUG: |
| dev_dbg(&dbgp.gadget->dev, "setup: desc debug\n"); |
| len = sizeof dbg_desc; |
| data = &dbg_desc; |
| break; |
| default: |
| goto fail; |
| } |
| err = 0; |
| } else if (request == USB_REQ_SET_FEATURE && |
| value == USB_DEVICE_DEBUG_MODE) { |
| dev_dbg(&dbgp.gadget->dev, "setup: feat debug\n"); |
| #ifdef CONFIG_USB_G_DBGP_PRINTK |
| err = dbgp_enable_ep(); |
| #else |
| err = dbgp_configure_endpoints(gadget); |
| if (err < 0) { |
| goto fail; |
| } |
| err = gserial_connect(dbgp.serial, tty_line); |
| #endif |
| if (err < 0) |
| goto fail; |
| } else |
| goto fail; |
| |
| req->length = min(length, len); |
| req->zero = len < req->length; |
| if (data && req->length) |
| memcpy(req->buf, data, req->length); |
| |
| req->complete = dbgp_setup_complete; |
| return usb_ep_queue(gadget->ep0, req, GFP_ATOMIC); |
| |
| fail: |
| dev_dbg(&dbgp.gadget->dev, |
| "setup: failure req %x v %x\n", request, value); |
| return err; |
| } |
| |
| static struct usb_gadget_driver dbgp_driver = { |
| .function = "dbgp", |
| .max_speed = USB_SPEED_HIGH, |
| .bind = dbgp_bind, |
| .unbind = dbgp_unbind, |
| .setup = dbgp_setup, |
| .reset = dbgp_disconnect, |
| .disconnect = dbgp_disconnect, |
| .driver = { |
| .owner = THIS_MODULE, |
| .name = "dbgp" |
| }, |
| }; |
| |
| static int __init dbgp_init(void) |
| { |
| return usb_gadget_register_driver(&dbgp_driver); |
| } |
| |
| static void __exit dbgp_exit(void) |
| { |
| usb_gadget_unregister_driver(&dbgp_driver); |
| #ifdef CONFIG_USB_G_DBGP_SERIAL |
| gserial_free_line(tty_line); |
| #endif |
| } |
| |
| MODULE_AUTHOR("Stephane Duverger"); |
| MODULE_DESCRIPTION("EHCI Debug Port device gadget"); |
| MODULE_LICENSE("GPL"); |
| module_init(dbgp_init); |
| module_exit(dbgp_exit); |