drivers/usb/gadget/legacy/hid.c

   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);