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 status = PTR_ERR(e->f); 104 goto put; 105 } 106 status = usb_add_function(c, e->f); 107 if (status < 0) { 108 usb_put_function(e->f); 109 goto put; 110 } 111 } 112 113 return 0; 114 put: 115 list_for_each_entry(n, &hidg_func_list, node) { 116 if (n == e) 117 break; 118 usb_remove_function(c, n->f); 119 usb_put_function(n->f); 120 } 121 return status; 122 } 123 124 static struct usb_configuration config_driver = { 125 .label = "HID Gadget", 126 .bConfigurationValue = 1, 127 /* .iConfiguration = DYNAMIC */ 128 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 129 }; 130 131 /****************************** Gadget Bind ******************************/ 132 133 static int hid_bind(struct usb_composite_dev *cdev) 134 { 135 struct usb_gadget *gadget = cdev->gadget; 136 struct list_head *tmp; 137 struct hidg_func_node *n = NULL, *m, *iter_n; 138 struct f_hid_opts *hid_opts; 139 int status, funcs = 0; 140 141 list_for_each(tmp, &hidg_func_list) 142 funcs++; 143 144 if (!funcs) 145 return -ENODEV; 146 147 list_for_each_entry(iter_n, &hidg_func_list, node) { 148 iter_n->fi = usb_get_function_instance("hid"); 149 if (IS_ERR(iter_n->fi)) { 150 status = PTR_ERR(iter_n->fi); 151 n = iter_n; 152 goto put; 153 } 154 hid_opts = container_of(iter_n->fi, struct f_hid_opts, func_inst); 155 hid_opts->subclass = iter_n->func->subclass; 156 hid_opts->protocol = iter_n->func->protocol; 157 hid_opts->report_length = iter_n->func->report_length; 158 hid_opts->report_desc_length = iter_n->func->report_desc_length; 159 hid_opts->report_desc = iter_n->func->report_desc; 160 } 161 162 163 /* Allocate string descriptor numbers ... note that string 164 * contents can be overridden by the composite_dev glue. 165 */ 166 167 status = usb_string_ids_tab(cdev, strings_dev); 168 if (status < 0) 169 goto put; 170 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; 171 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 172 173 if (gadget_is_otg(gadget) && !otg_desc[0]) { 174 struct usb_descriptor_header *usb_desc; 175 176 usb_desc = usb_otg_descriptor_alloc(gadget); 177 if (!usb_desc) { 178 status = -ENOMEM; 179 goto put; 180 } 181 usb_otg_descriptor_init(gadget, usb_desc); 182 otg_desc[0] = usb_desc; 183 otg_desc[1] = NULL; 184 } 185 186 /* register our configuration */ 187 status = usb_add_config(cdev, &config_driver, do_config); 188 if (status < 0) 189 goto free_otg_desc; 190 191 usb_composite_overwrite_options(cdev, &coverwrite); 192 dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n"); 193 194 return 0; 195 196 free_otg_desc: 197 kfree(otg_desc[0]); 198 otg_desc[0] = NULL; 199 put: 200 list_for_each_entry(m, &hidg_func_list, node) { 201 if (m == n) 202 break; 203 usb_put_function_instance(m->fi); 204 } 205 return status; 206 } 207 208 static int hid_unbind(struct usb_composite_dev *cdev) 209 { 210 struct hidg_func_node *n; 211 212 list_for_each_entry(n, &hidg_func_list, node) { 213 usb_put_function(n->f); 214 usb_put_function_instance(n->fi); 215 } 216 217 kfree(otg_desc[0]); 218 otg_desc[0] = NULL; 219 220 return 0; 221 } 222 223 static int hidg_plat_driver_probe(struct platform_device *pdev) 224 { 225 struct hidg_func_descriptor *func = dev_get_platdata(&pdev->dev); 226 struct hidg_func_node *entry; 227 228 if (!func) { 229 dev_err(&pdev->dev, "Platform data missing\n"); 230 return -ENODEV; 231 } 232 233 entry = kzalloc(sizeof(*entry), GFP_KERNEL); 234 if (!entry) 235 return -ENOMEM; 236 237 entry->func = func; 238 list_add_tail(&entry->node, &hidg_func_list); 239 240 return 0; 241 } 242 243 static int hidg_plat_driver_remove(struct platform_device *pdev) 244 { 245 struct hidg_func_node *e, *n; 246 247 list_for_each_entry_safe(e, n, &hidg_func_list, node) { 248 list_del(&e->node); 249 kfree(e); 250 } 251 252 return 0; 253 } 254 255 256 /****************************** Some noise ******************************/ 257 258 259 static struct usb_composite_driver hidg_driver = { 260 .name = "g_hid", 261 .dev = &device_desc, 262 .strings = dev_strings, 263 .max_speed = USB_SPEED_HIGH, 264 .bind = hid_bind, 265 .unbind = hid_unbind, 266 }; 267 268 static struct platform_driver hidg_plat_driver = { 269 .remove = hidg_plat_driver_remove, 270 .driver = { 271 .name = "hidg", 272 }, 273 }; 274 275 276 MODULE_DESCRIPTION(DRIVER_DESC); 277 MODULE_AUTHOR("Fabien Chouteau, Peter Korsgaard"); 278 MODULE_LICENSE("GPL"); 279 280 static int __init hidg_init(void) 281 { 282 int status; 283 284 status = platform_driver_probe(&hidg_plat_driver, 285 hidg_plat_driver_probe); 286 if (status < 0) 287 return status; 288 289 status = usb_composite_probe(&hidg_driver); 290 if (status < 0) 291 platform_driver_unregister(&hidg_plat_driver); 292 293 return status; 294 } 295 module_init(hidg_init); 296 297 static void __exit hidg_cleanup(void) 298 { 299 usb_composite_unregister(&hidg_driver); 300 platform_driver_unregister(&hidg_plat_driver); 301 } 302 module_exit(hidg_cleanup); 303