drivers/usb/common/common.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Provides code common for host and device side USB.
   4  *
   5  * If either host side (ie. CONFIG_USB=y) or device side USB stack
   6  * (ie. CONFIG_USB_GADGET=y) is compiled in the kernel, this module is
   7  * compiled-in as well.  Otherwise, if either of the two stacks is
   8  * compiled as module, this file is compiled as module as well.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/of.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/usb/ch9.h>
  16 #include <linux/usb/of.h>
  17 #include <linux/usb/otg.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/debugfs.h>
  20 #include "common.h"
  21
  22 static const char *const ep_type_names[] = {
  23         [USB_ENDPOINT_XFER_CONTROL] = "ctrl",
  24         [USB_ENDPOINT_XFER_ISOC] = "isoc",
  25         [USB_ENDPOINT_XFER_BULK] = "bulk",
  26         [USB_ENDPOINT_XFER_INT] = "intr",
  27 };
  28
  29 /**
  30  * usb_ep_type_string() - Returns human readable-name of the endpoint type.
  31  * @ep_type: The endpoint type to return human-readable name for.  If it's not
  32  *   any of the types: USB_ENDPOINT_XFER_{CONTROL, ISOC, BULK, INT},
  33  *   usually got by usb_endpoint_type(), the string 'unknown' will be returned.
  34  */
  35 const char *usb_ep_type_string(int ep_type)
  36 {
  37         if (ep_type < 0 || ep_type >= ARRAY_SIZE(ep_type_names))
  38                 return "unknown";
  39
  40         return ep_type_names[ep_type];
  41 }
  42 EXPORT_SYMBOL_GPL(usb_ep_type_string);
  43
  44 const char *usb_otg_state_string(enum usb_otg_state state)
  45 {
  46         static const char *const names[] = {
  47                 [OTG_STATE_A_IDLE] = "a_idle",
  48                 [OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
  49                 [OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
  50                 [OTG_STATE_A_HOST] = "a_host",
  51                 [OTG_STATE_A_SUSPEND] = "a_suspend",
  52                 [OTG_STATE_A_PERIPHERAL] = "a_peripheral",
  53                 [OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
  54                 [OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
  55                 [OTG_STATE_B_IDLE] = "b_idle",
  56                 [OTG_STATE_B_SRP_INIT] = "b_srp_init",
  57                 [OTG_STATE_B_PERIPHERAL] = "b_peripheral",
  58                 [OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
  59                 [OTG_STATE_B_HOST] = "b_host",
  60         };
  61
  62         if (state < 0 || state >= ARRAY_SIZE(names))
  63                 return "UNDEFINED";
  64
  65         return names[state];
  66 }
  67 EXPORT_SYMBOL_GPL(usb_otg_state_string);
  68
  69 static const char *const speed_names[] = {
  70         [USB_SPEED_UNKNOWN] = "UNKNOWN",
  71         [USB_SPEED_LOW] = "low-speed",
  72         [USB_SPEED_FULL] = "full-speed",
  73         [USB_SPEED_HIGH] = "high-speed",
  74         [USB_SPEED_WIRELESS] = "wireless",
  75         [USB_SPEED_SUPER] = "super-speed",
  76         [USB_SPEED_SUPER_PLUS] = "super-speed-plus",
  77 };
  78
  79 static const char *const ssp_rate[] = {
  80         [USB_SSP_GEN_UNKNOWN] = "UNKNOWN",
  81         [USB_SSP_GEN_2x1] = "super-speed-plus-gen2x1",
  82         [USB_SSP_GEN_1x2] = "super-speed-plus-gen1x2",
  83         [USB_SSP_GEN_2x2] = "super-speed-plus-gen2x2",
  84 };
  85
  86 /**
  87  * usb_speed_string() - Returns human readable-name of the speed.
  88  * @speed: The speed to return human-readable name for.  If it's not
  89  *   any of the speeds defined in usb_device_speed enum, string for
  90  *   USB_SPEED_UNKNOWN will be returned.
  91  */
  92 const char *usb_speed_string(enum usb_device_speed speed)
  93 {
  94         if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
  95                 speed = USB_SPEED_UNKNOWN;
  96         return speed_names[speed];
  97 }
  98 EXPORT_SYMBOL_GPL(usb_speed_string);
  99
 100 /**
 101  * usb_get_maximum_speed - Get maximum requested speed for a given USB
 102  * controller.
 103  * @dev: Pointer to the given USB controller device
 104  *
 105  * The function gets the maximum speed string from property "maximum-speed",
 106  * and returns the corresponding enum usb_device_speed.
 107  */
 108 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
 109 {
 110         const char *p = "maximum-speed";
 111         int ret;
 112
 113         ret = device_property_match_property_string(dev, p, ssp_rate, ARRAY_SIZE(ssp_rate));
 114         if (ret > 0)
 115                 return USB_SPEED_SUPER_PLUS;
 116
 117         ret = device_property_match_property_string(dev, p, speed_names, ARRAY_SIZE(speed_names));
 118         if (ret > 0)
 119                 return ret;
 120
 121         return USB_SPEED_UNKNOWN;
 122 }
 123 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
 124
 125 /**
 126  * usb_get_maximum_ssp_rate - Get the signaling rate generation and lane count
 127  *      of a SuperSpeed Plus capable device.
 128  * @dev: Pointer to the given USB controller device
 129  *
 130  * If the string from "maximum-speed" property is super-speed-plus-genXxY where
 131  * 'X' is the generation number and 'Y' is the number of lanes, then this
 132  * function returns the corresponding enum usb_ssp_rate.
 133  */
 134 enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev)
 135 {
 136         const char *maximum_speed;
 137         int ret;
 138
 139         ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
 140         if (ret < 0)
 141                 return USB_SSP_GEN_UNKNOWN;
 142
 143         ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
 144         return (ret < 0) ? USB_SSP_GEN_UNKNOWN : ret;
 145 }
 146 EXPORT_SYMBOL_GPL(usb_get_maximum_ssp_rate);
 147
 148 /**
 149  * usb_state_string - Returns human readable name for the state.
 150  * @state: The state to return a human-readable name for. If it's not
 151  *      any of the states devices in usb_device_state_string enum,
 152  *      the string UNKNOWN will be returned.
 153  */
 154 const char *usb_state_string(enum usb_device_state state)
 155 {
 156         static const char *const names[] = {
 157                 [USB_STATE_NOTATTACHED] = "not attached",
 158                 [USB_STATE_ATTACHED] = "attached",
 159                 [USB_STATE_POWERED] = "powered",
 160                 [USB_STATE_RECONNECTING] = "reconnecting",
 161                 [USB_STATE_UNAUTHENTICATED] = "unauthenticated",
 162                 [USB_STATE_DEFAULT] = "default",
 163                 [USB_STATE_ADDRESS] = "addressed",
 164                 [USB_STATE_CONFIGURED] = "configured",
 165                 [USB_STATE_SUSPENDED] = "suspended",
 166         };
 167
 168         if (state < 0 || state >= ARRAY_SIZE(names))
 169                 return "UNKNOWN";
 170
 171         return names[state];
 172 }
 173 EXPORT_SYMBOL_GPL(usb_state_string);
 174
 175 static const char *const usb_dr_modes[] = {
 176         [USB_DR_MODE_UNKNOWN]           = "",
 177         [USB_DR_MODE_HOST]              = "host",
 178         [USB_DR_MODE_PERIPHERAL]        = "peripheral",
 179         [USB_DR_MODE_OTG]               = "otg",
 180 };
 181
 182 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
 183 {
 184         int ret;
 185
 186         ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
 187         return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
 188 }
 189
 190 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
 191 {
 192         const char *dr_mode;
 193         int err;
 194
 195         err = device_property_read_string(dev, "dr_mode", &dr_mode);
 196         if (err < 0)
 197                 return USB_DR_MODE_UNKNOWN;
 198
 199         return usb_get_dr_mode_from_string(dr_mode);
 200 }
 201 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
 202
 203 /**
 204  * usb_get_role_switch_default_mode - Get default mode for given device
 205  * @dev: Pointer to the given device
 206  *
 207  * The function gets string from property 'role-switch-default-mode',
 208  * and returns the corresponding enum usb_dr_mode.
 209  */
 210 enum usb_dr_mode usb_get_role_switch_default_mode(struct device *dev)
 211 {
 212         const char *str;
 213         int ret;
 214
 215         ret = device_property_read_string(dev, "role-switch-default-mode", &str);
 216         if (ret < 0)
 217                 return USB_DR_MODE_UNKNOWN;
 218
 219         return usb_get_dr_mode_from_string(str);
 220 }
 221 EXPORT_SYMBOL_GPL(usb_get_role_switch_default_mode);
 222
 223 /**
 224  * usb_decode_interval - Decode bInterval into the time expressed in 1us unit
 225  * @epd: The descriptor of the endpoint
 226  * @speed: The speed that the endpoint works as
 227  *
 228  * Function returns the interval expressed in 1us unit for servicing
 229  * endpoint for data transfers.
 230  */
 231 unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
 232                                  enum usb_device_speed speed)
 233 {
 234         unsigned int interval = 0;
 235
 236         switch (usb_endpoint_type(epd)) {
 237         case USB_ENDPOINT_XFER_CONTROL:
 238                 /* uframes per NAK */
 239                 if (speed == USB_SPEED_HIGH)
 240                         interval = epd->bInterval;
 241                 break;
 242         case USB_ENDPOINT_XFER_ISOC:
 243                 interval = 1 << (epd->bInterval - 1);
 244                 break;
 245         case USB_ENDPOINT_XFER_BULK:
 246                 /* uframes per NAK */
 247                 if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
 248                         interval = epd->bInterval;
 249                 break;
 250         case USB_ENDPOINT_XFER_INT:
 251                 if (speed >= USB_SPEED_HIGH)
 252                         interval = 1 << (epd->bInterval - 1);
 253                 else
 254                         interval = epd->bInterval;
 255                 break;
 256         }
 257
 258         interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;
 259
 260         return interval;
 261 }
 262 EXPORT_SYMBOL_GPL(usb_decode_interval);
 263
 264 #ifdef CONFIG_OF
 265 /**
 266  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
 267  * which is associated with the given phy device_node
 268  * @np: Pointer to the given phy device_node
 269  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
 270  *        phys which do not have phy-cells
 271  *
 272  * In dts a usb controller associates with phy devices.  The function gets
 273  * the string from property 'dr_mode' of the controller associated with the
 274  * given phy device node, and returns the correspondig enum usb_dr_mode.
 275  */
 276 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
 277 {
 278         struct device_node *controller;
 279         struct of_phandle_args args;
 280         const char *dr_mode;
 281         int index;
 282         int err;
 283
 284         for_each_node_with_property(controller, "phys") {
 285                 if (!of_device_is_available(controller))
 286                         continue;
 287                 index = 0;
 288                 do {
 289                         if (arg0 == -1) {
 290                                 args.np = of_parse_phandle(controller, "phys",
 291                                                         index);
 292                                 args.args_count = 0;
 293                         } else {
 294                                 err = of_parse_phandle_with_args(controller,
 295                                                         "phys", "#phy-cells",
 296                                                         index, &args);
 297                                 if (err)
 298                                         break;
 299                         }
 300
 301                         of_node_put(args.np);
 302                         if (args.np == np && (args.args_count == 0 ||
 303                                               args.args[0] == arg0))
 304                                 goto finish;
 305                         index++;
 306                 } while (args.np);
 307         }
 308
 309 finish:
 310         err = of_property_read_string(controller, "dr_mode", &dr_mode);
 311         of_node_put(controller);
 312
 313         if (err < 0)
 314                 return USB_DR_MODE_UNKNOWN;
 315
 316         return usb_get_dr_mode_from_string(dr_mode);
 317 }
 318 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
 319
 320 /**
 321  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 322  * for given targeted hosts (non-PC hosts)
 323  * @np: Pointer to the given device_node
 324  *
 325  * The function gets if the targeted hosts support TPL or not
 326  */
 327 bool of_usb_host_tpl_support(struct device_node *np)
 328 {
 329         return of_property_read_bool(np, "tpl-support");
 330 }
 331 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
 332
 333 /**
 334  * of_usb_update_otg_caps - to update usb otg capabilities according to
 335  * the passed properties in DT.
 336  * @np: Pointer to the given device_node
 337  * @otg_caps: Pointer to the target usb_otg_caps to be set
 338  *
 339  * The function updates the otg capabilities
 340  */
 341 int of_usb_update_otg_caps(struct device_node *np,
 342                         struct usb_otg_caps *otg_caps)
 343 {
 344         u32 otg_rev;
 345
 346         if (!otg_caps)
 347                 return -EINVAL;
 348
 349         if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
 350                 switch (otg_rev) {
 351                 case 0x0100:
 352                 case 0x0120:
 353                 case 0x0130:
 354                 case 0x0200:
 355                         /* Choose the lesser one if it's already been set */
 356                         if (otg_caps->otg_rev)
 357                                 otg_caps->otg_rev = min_t(u16, otg_rev,
 358                                                         otg_caps->otg_rev);
 359                         else
 360                                 otg_caps->otg_rev = otg_rev;
 361                         break;
 362                 default:
 363                         pr_err("%pOF: unsupported otg-rev: 0x%x\n",
 364                                                 np, otg_rev);
 365                         return -EINVAL;
 366                 }
 367         } else {
 368                 /*
 369                  * otg-rev is mandatory for otg properties, if not passed
 370                  * we set it to be 0 and assume it's a legacy otg device.
 371                  * Non-dt platform can set it afterwards.
 372                  */
 373                 otg_caps->otg_rev = 0;
 374         }
 375
 376         if (of_property_read_bool(np, "hnp-disable"))
 377                 otg_caps->hnp_support = false;
 378         if (of_property_read_bool(np, "srp-disable"))
 379                 otg_caps->srp_support = false;
 380         if (of_property_read_bool(np, "adp-disable") ||
 381                                 (otg_caps->otg_rev < 0x0200))
 382                 otg_caps->adp_support = false;
 383
 384         return 0;
 385 }
 386 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
 387
 388 /**
 389  * usb_of_get_companion_dev - Find the companion device
 390  * @dev: the device pointer to find a companion
 391  *
 392  * Find the companion device from platform bus.
 393  *
 394  * Takes a reference to the returned struct device which needs to be dropped
 395  * after use.
 396  *
 397  * Return: On success, a pointer to the companion device, %NULL on failure.
 398  */
 399 struct device *usb_of_get_companion_dev(struct device *dev)
 400 {
 401         struct device_node *node;
 402         struct platform_device *pdev = NULL;
 403
 404         node = of_parse_phandle(dev->of_node, "companion", 0);
 405         if (node)
 406                 pdev = of_find_device_by_node(node);
 407
 408         of_node_put(node);
 409
 410         return pdev ? &pdev->dev : NULL;
 411 }
 412 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
 413 #endif
 414
 415 struct dentry *usb_debug_root;
 416 EXPORT_SYMBOL_GPL(usb_debug_root);
 417
 418 DEFINE_MUTEX(usb_dynids_lock);
 419 EXPORT_SYMBOL_GPL(usb_dynids_lock);
 420
 421 static int __init usb_common_init(void)
 422 {
 423         usb_debug_root = debugfs_create_dir("usb", NULL);
 424         ledtrig_usb_init();
 425         return 0;
 426 }
 427
 428 static void __exit usb_common_exit(void)
 429 {
 430         ledtrig_usb_exit();
 431         debugfs_remove_recursive(usb_debug_root);
 432 }
 433
 434 subsys_initcall(usb_common_init);
 435 module_exit(usb_common_exit);
 436
 437 MODULE_DESCRIPTION("Common code for host and device side USB");
 438 MODULE_LICENSE("GPL");