linux/drivers/usb/gadget/legacy/hid.c
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   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
  30struct 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
  37static LIST_HEAD(hidg_func_list);
  38
  39/*-------------------------------------------------------------------------*/
  40USB_GADGET_COMPOSITE_OPTIONS();
  41
  42static 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
  66static const struct usb_descriptor_header *otg_desc[2];
  67
  68/* string IDs are assigned dynamically */
  69static 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
  76static struct usb_gadget_strings stringtab_dev = {
  77        .language       = 0x0409,       /* en-us */
  78        .strings        = strings_dev,
  79};
  80
  81static struct usb_gadget_strings *dev_strings[] = {
  82        &stringtab_dev,
  83        NULL,
  84};
  85
  86
  87
  88/****************************** Configurations ******************************/
  89
  90static 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;
 112put:
 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
 122static 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
 131static 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
 191free_otg_desc:
 192        kfree(otg_desc[0]);
 193        otg_desc[0] = NULL;
 194put:
 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
 203static 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
 218static 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
 238static 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
 254static 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
 263static struct platform_driver hidg_plat_driver = {
 264        .remove         = hidg_plat_driver_remove,
 265        .driver         = {
 266                .name   = "hidg",
 267        },
 268};
 269
 270
 271MODULE_DESCRIPTION(DRIVER_DESC);
 272MODULE_AUTHOR("Fabien Chouteau, Peter Korsgaard");
 273MODULE_LICENSE("GPL");
 274
 275static 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}
 290module_init(hidg_init);
 291
 292static void __exit hidg_cleanup(void)
 293{
 294        usb_composite_unregister(&hidg_driver);
 295        platform_driver_unregister(&hidg_plat_driver);
 296}
 297module_exit(hidg_cleanup);
 298