1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * ncm.c -- NCM gadget driver 4 * 5 * Copyright (C) 2010 Nokia Corporation 6 * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com> 7 * 8 * The driver borrows from ether.c which is: 9 * 10 * Copyright (C) 2003-2005,2008 David Brownell 11 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger 12 * Copyright (C) 2008 Nokia Corporation 13 */ 14 15 /* #define DEBUG */ 16 /* #define VERBOSE_DEBUG */ 17 18 #include <linux/kernel.h> 19 #include <linux/module.h> 20 #include <linux/usb/composite.h> 21 22 #include "u_ether.h" 23 #include "u_ncm.h" 24 25 #define DRIVER_DESC "NCM Gadget" 26 27 /*-------------------------------------------------------------------------*/ 28 29 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!! 30 * Instead: allocate your own, using normal USB-IF procedures. 31 */ 32 33 /* Thanks to NetChip Technologies for donating this product ID. 34 * It's for devices with only CDC Ethernet configurations. 35 */ 36 #define CDC_VENDOR_NUM 0x0525 /* NetChip */ 37 #define CDC_PRODUCT_NUM 0xa4a1 /* Linux-USB Ethernet Gadget */ 38 39 /*-------------------------------------------------------------------------*/ 40 USB_GADGET_COMPOSITE_OPTIONS(); 41 42 USB_ETHERNET_MODULE_PARAMETERS(); 43 44 static struct usb_device_descriptor device_desc = { 45 .bLength = sizeof device_desc, 46 .bDescriptorType = USB_DT_DEVICE, 47 48 /* .bcdUSB = DYNAMIC */ 49 50 .bDeviceClass = USB_CLASS_COMM, 51 .bDeviceSubClass = 0, 52 .bDeviceProtocol = 0, 53 /* .bMaxPacketSize0 = f(hardware) */ 54 55 /* Vendor and product id defaults change according to what configs 56 * we support. (As does bNumConfigurations.) These values can 57 * also be overridden by module parameters. 58 */ 59 .idVendor = cpu_to_le16 (CDC_VENDOR_NUM), 60 .idProduct = cpu_to_le16 (CDC_PRODUCT_NUM), 61 /* .bcdDevice = f(hardware) */ 62 /* .iManufacturer = DYNAMIC */ 63 /* .iProduct = DYNAMIC */ 64 /* NO SERIAL NUMBER */ 65 .bNumConfigurations = 1, 66 }; 67 68 static const struct usb_descriptor_header *otg_desc[2]; 69 70 /* string IDs are assigned dynamically */ 71 static struct usb_string strings_dev[] = { 72 [USB_GADGET_MANUFACTURER_IDX].s = "", 73 [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC, 74 [USB_GADGET_SERIAL_IDX].s = "", 75 { } /* end of list */ 76 }; 77 78 static struct usb_gadget_strings stringtab_dev = { 79 .language = 0x0409, /* en-us */ 80 .strings = strings_dev, 81 }; 82 83 static struct usb_gadget_strings *dev_strings[] = { 84 &stringtab_dev, 85 NULL, 86 }; 87 88 static struct usb_function_instance *f_ncm_inst; 89 static struct usb_function *f_ncm; 90 91 /*-------------------------------------------------------------------------*/ 92 93 static int ncm_do_config(struct usb_configuration *c) 94 { 95 int status; 96 97 /* FIXME alloc iConfiguration string, set it in c->strings */ 98 99 if (gadget_is_otg(c->cdev->gadget)) { 100 c->descriptors = otg_desc; 101 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP; 102 } 103 104 f_ncm = usb_get_function(f_ncm_inst); 105 if (IS_ERR(f_ncm)) 106 return PTR_ERR(f_ncm); 107 108 status = usb_add_function(c, f_ncm); 109 if (status < 0) { 110 usb_put_function(f_ncm); 111 return status; 112 } 113 114 return 0; 115 } 116 117 static struct usb_configuration ncm_config_driver = { 118 /* .label = f(hardware) */ 119 .label = "CDC Ethernet (NCM)", 120 .bConfigurationValue = 1, 121 /* .iConfiguration = DYNAMIC */ 122 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 123 }; 124 125 /*-------------------------------------------------------------------------*/ 126 127 static int gncm_bind(struct usb_composite_dev *cdev) 128 { 129 struct usb_gadget *gadget = cdev->gadget; 130 struct f_ncm_opts *ncm_opts; 131 int status; 132 133 f_ncm_inst = usb_get_function_instance("ncm"); 134 if (IS_ERR(f_ncm_inst)) 135 return PTR_ERR(f_ncm_inst); 136 137 ncm_opts = container_of(f_ncm_inst, struct f_ncm_opts, func_inst); 138 139 gether_set_qmult(ncm_opts->net, qmult); 140 if (!gether_set_host_addr(ncm_opts->net, host_addr)) 141 pr_info("using host ethernet address: %s", host_addr); 142 if (!gether_set_dev_addr(ncm_opts->net, dev_addr)) 143 pr_info("using self ethernet address: %s", dev_addr); 144 145 /* Allocate string descriptor numbers ... note that string 146 * contents can be overridden by the composite_dev glue. 147 */ 148 149 status = usb_string_ids_tab(cdev, strings_dev); 150 if (status < 0) 151 goto fail; 152 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; 153 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 154 155 if (gadget_is_otg(gadget) && !otg_desc[0]) { 156 struct usb_descriptor_header *usb_desc; 157 158 usb_desc = usb_otg_descriptor_alloc(gadget); 159 if (!usb_desc) 160 goto fail; 161 usb_otg_descriptor_init(gadget, usb_desc); 162 otg_desc[0] = usb_desc; 163 otg_desc[1] = NULL; 164 } 165 166 status = usb_add_config(cdev, &ncm_config_driver, 167 ncm_do_config); 168 if (status < 0) 169 goto fail1; 170 171 usb_composite_overwrite_options(cdev, &coverwrite); 172 dev_info(&gadget->dev, "%s\n", DRIVER_DESC); 173 174 return 0; 175 176 fail1: 177 kfree(otg_desc[0]); 178 otg_desc[0] = NULL; 179 fail: 180 usb_put_function_instance(f_ncm_inst); 181 return status; 182 } 183 184 static int gncm_unbind(struct usb_composite_dev *cdev) 185 { 186 if (!IS_ERR_OR_NULL(f_ncm)) 187 usb_put_function(f_ncm); 188 if (!IS_ERR_OR_NULL(f_ncm_inst)) 189 usb_put_function_instance(f_ncm_inst); 190 kfree(otg_desc[0]); 191 otg_desc[0] = NULL; 192 193 return 0; 194 } 195 196 static struct usb_composite_driver ncm_driver = { 197 .name = "g_ncm", 198 .dev = &device_desc, 199 .strings = dev_strings, 200 .max_speed = USB_SPEED_SUPER, 201 .bind = gncm_bind, 202 .unbind = gncm_unbind, 203 }; 204 205 module_usb_composite_driver(ncm_driver); 206 207 MODULE_DESCRIPTION(DRIVER_DESC); 208 MODULE_AUTHOR("Yauheni Kaliuta"); 209 MODULE_LICENSE("GPL"); 210