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