1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * hid.c -- HID Composite driver 4 * 5 * Based on multi.c 6 * 7 * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com> 8 */ 9 10 11 #include <linux/kernel.h> 12 #include <linux/platform_device.h> 13 #include <linux/list.h> 14 #include <linux/module.h> 15 #include <linux/usb/composite.h> 16 #include <linux/usb/g_hid.h> 17 18 #define DRIVER_DESC "HID Gadget" 19 #define DRIVER_VERSION "2010/03/16" 20 21 #include "u_hid.h" 22 23 /*-------------------------------------------------------------------------*/ 24 25 #define HIDG_VENDOR_NUM 0x0525 /* XXX NetChip */ 26 #define HIDG_PRODUCT_NUM 0xa4ac /* Linux-USB HID gadget */ 27 28 /*-------------------------------------------------------------------------*/ 29 30 struct hidg_func_node { 31 struct usb_function_instance *fi; 32 struct usb_function *f; 33 struct list_head node; 34 struct hidg_func_descriptor *func; 35 }; 36 37 static LIST_HEAD(hidg_func_list); 38 39 /*-------------------------------------------------------------------------*/ 40 USB_GADGET_COMPOSITE_OPTIONS(); 41 42 static struct usb_device_descriptor device_desc = { 43 .bLength = sizeof device_desc, 44 .bDescriptorType = USB_DT_DEVICE, 45 46 /* .bcdUSB = DYNAMIC */ 47 48 /* .bDeviceClass = USB_CLASS_COMM, */ 49 /* .bDeviceSubClass = 0, */ 50 /* .bDeviceProtocol = 0, */ 51 .bDeviceClass = USB_CLASS_PER_INTERFACE, 52 .bDeviceSubClass = 0, 53 .bDeviceProtocol = 0, 54 /* .bMaxPacketSize0 = f(hardware) */ 55 56 /* Vendor and product id can be overridden by module parameters. */ 57 .idVendor = cpu_to_le16(HIDG_VENDOR_NUM), 58 .idProduct = cpu_to_le16(HIDG_PRODUCT_NUM), 59 /* .bcdDevice = f(hardware) */ 60 /* .iManufacturer = DYNAMIC */ 61 /* .iProduct = DYNAMIC */ 62 /* NO SERIAL NUMBER */ 63 .bNumConfigurations = 1, 64 }; 65 66 static const struct usb_descriptor_header *otg_desc[2]; 67 68 /* string IDs are assigned dynamically */ 69 static struct usb_string strings_dev[] = { 70 [USB_GADGET_MANUFACTURER_IDX].s = "", 71 [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC, 72 [USB_GADGET_SERIAL_IDX].s = "", 73 { } /* end of list */ 74 }; 75 76 static struct usb_gadget_strings stringtab_dev = { 77 .language = 0x0409, /* en-us */ 78 .strings = strings_dev, 79 }; 80 81 static struct usb_gadget_strings *dev_strings[] = { 82 &stringtab_dev, 83 NULL, 84 }; 85 86 87 88 /****************************** Configurations ******************************/ 89 90 static int do_config(struct usb_configuration *c) 91 { 92 struct hidg_func_node *e, *n; 93 int status = 0; 94 95 if (gadget_is_otg(c->cdev->gadget)) { 96 c->descriptors = otg_desc; 97 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP; 98 } 99 100 list_for_each_entry(e, &hidg_func_list, node) { 101 e->f = usb_get_function(e->fi); 102 if (IS_ERR(e->f)) 103 goto put; 104 status = usb_add_function(c, e->f); 105 if (status < 0) { 106 usb_put_function(e->f); 107 goto put; 108 } 109 } 110 111 return 0; 112 put: 113 list_for_each_entry(n, &hidg_func_list, node) { 114 if (n == e) 115 break; 116 usb_remove_function(c, n->f); 117 usb_put_function(n->f); 118 } 119 return status; 120 } 121 122 static struct usb_configuration config_driver = { 123 .label = "HID Gadget", 124 .bConfigurationValue = 1, 125 /* .iConfiguration = DYNAMIC */ 126 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 127 }; 128 129 /****************************** Gadget Bind ******************************/ 130 131 static int hid_bind(struct usb_composite_dev *cdev) 132 { 133 struct usb_gadget *gadget = cdev->gadget; 134 struct list_head *tmp; 135 struct hidg_func_node *n, *m; 136 struct f_hid_opts *hid_opts; 137 int status, funcs = 0; 138 139 list_for_each(tmp, &hidg_func_list) 140 funcs++; 141 142 if (!funcs) 143 return -ENODEV; 144 145 list_for_each_entry(n, &hidg_func_list, node) { 146 n->fi = usb_get_function_instance("hid"); 147 if (IS_ERR(n->fi)) { 148 status = PTR_ERR(n->fi); 149 goto put; 150 } 151 hid_opts = container_of(n->fi, struct f_hid_opts, func_inst); 152 hid_opts->subclass = n->func->subclass; 153 hid_opts->protocol = n->func->protocol; 154 hid_opts->report_length = n->func->report_length; 155 hid_opts->report_desc_length = n->func->report_desc_length; 156 hid_opts->report_desc = n->func->report_desc; 157 } 158 159 160 /* Allocate string descriptor numbers ... note that string 161 * contents can be overridden by the composite_dev glue. 162 */ 163 164 status = usb_string_ids_tab(cdev, strings_dev); 165 if (status < 0) 166 goto put; 167 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; 168 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 169 170 if (gadget_is_otg(gadget) && !otg_desc[0]) { 171 struct usb_descriptor_header *usb_desc; 172 173 usb_desc = usb_otg_descriptor_alloc(gadget); 174 if (!usb_desc) 175 goto put; 176 usb_otg_descriptor_init(gadget, usb_desc); 177 otg_desc[0] = usb_desc; 178 otg_desc[1] = NULL; 179 } 180 181 /* register our configuration */ 182 status = usb_add_config(cdev, &config_driver, do_config); 183 if (status < 0) 184 goto free_otg_desc; 185 186 usb_composite_overwrite_options(cdev, &coverwrite); 187 dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n"); 188 189 return 0; 190 191 free_otg_desc: 192 kfree(otg_desc[0]); 193 otg_desc[0] = NULL; 194 put: 195 list_for_each_entry(m, &hidg_func_list, node) { 196 if (m == n) 197 break; 198 usb_put_function_instance(m->fi); 199 } 200 return status; 201 } 202 203 static int hid_unbind(struct usb_composite_dev *cdev) 204 { 205 struct hidg_func_node *n; 206 207 list_for_each_entry(n, &hidg_func_list, node) { 208 usb_put_function(n->f); 209 usb_put_function_instance(n->fi); 210 } 211 212 kfree(otg_desc[0]); 213 otg_desc[0] = NULL; 214 215 return 0; 216 } 217 218 static int hidg_plat_driver_probe(struct platform_device *pdev) 219 { 220 struct hidg_func_descriptor *func = dev_get_platdata(&pdev->dev); 221 struct hidg_func_node *entry; 222 223 if (!func) { 224 dev_err(&pdev->dev, "Platform data missing\n"); 225 return -ENODEV; 226 } 227 228 entry = kzalloc(sizeof(*entry), GFP_KERNEL); 229 if (!entry) 230 return -ENOMEM; 231 232 entry->func = func; 233 list_add_tail(&entry->node, &hidg_func_list); 234 235 return 0; 236 } 237 238 static int hidg_plat_driver_remove(struct platform_device *pdev) 239 { 240 struct hidg_func_node *e, *n; 241 242 list_for_each_entry_safe(e, n, &hidg_func_list, node) { 243 list_del(&e->node); 244 kfree(e); 245 } 246 247 return 0; 248 } 249 250 251 /****************************** Some noise ******************************/ 252 253 254 static struct usb_composite_driver hidg_driver = { 255 .name = "g_hid", 256 .dev = &device_desc, 257 .strings = dev_strings, 258 .max_speed = USB_SPEED_HIGH, 259 .bind = hid_bind, 260 .unbind = hid_unbind, 261 }; 262 263 static struct platform_driver hidg_plat_driver = { 264 .remove = hidg_plat_driver_remove, 265 .driver = { 266 .name = "hidg", 267 }, 268 }; 269 270 271 MODULE_DESCRIPTION(DRIVER_DESC); 272 MODULE_AUTHOR("Fabien Chouteau, Peter Korsgaard"); 273 MODULE_LICENSE("GPL"); 274 275 static int __init hidg_init(void) 276 { 277 int status; 278 279 status = platform_driver_probe(&hidg_plat_driver, 280 hidg_plat_driver_probe); 281 if (status < 0) 282 return status; 283 284 status = usb_composite_probe(&hidg_driver); 285 if (status < 0) 286 platform_driver_unregister(&hidg_plat_driver); 287 288 return status; 289 } 290 module_init(hidg_init); 291 292 static void __exit hidg_cleanup(void) 293 { 294 usb_composite_unregister(&hidg_driver); 295 platform_driver_unregister(&hidg_plat_driver); 296 } 297 module_exit(hidg_cleanup); 298