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 *maximum_speed;
 111         int ret;
 112
 113         ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
 114         if (ret < 0)
 115                 return USB_SPEED_UNKNOWN;
 116
 117         ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
 118         if (ret > 0)
 119                 return USB_SPEED_SUPER_PLUS;
 120
 121         ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
 122         return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
 123 }
 124 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
 125
 126 /**
 127  * usb_get_maximum_ssp_rate - Get the signaling rate generation and lane count
 128  *      of a SuperSpeed Plus capable device.
 129  * @dev: Pointer to the given USB controller device
 130  *
 131  * If the string from "maximum-speed" property is super-speed-plus-genXxY where
 132  * 'X' is the generation number and 'Y' is the number of lanes, then this
 133  * function returns the corresponding enum usb_ssp_rate.
 134  */
 135 enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev)
 136 {
 137         const char *maximum_speed;
 138         int ret;
 139
 140         ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
 141         if (ret < 0)
 142                 return USB_SSP_GEN_UNKNOWN;
 143
 144         ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
 145         return (ret < 0) ? USB_SSP_GEN_UNKNOWN : ret;
 146 }
 147 EXPORT_SYMBOL_GPL(usb_get_maximum_ssp_rate);
 148
 149 /**
 150  * usb_state_string - Returns human readable name for the state.
 151  * @state: The state to return a human-readable name for. If it's not
 152  *      any of the states devices in usb_device_state_string enum,
 153  *      the string UNKNOWN will be returned.
 154  */
 155 const char *usb_state_string(enum usb_device_state state)
 156 {
 157         static const char *const names[] = {
 158                 [USB_STATE_NOTATTACHED] = "not attached",
 159                 [USB_STATE_ATTACHED] = "attached",
 160                 [USB_STATE_POWERED] = "powered",
 161                 [USB_STATE_RECONNECTING] = "reconnecting",
 162                 [USB_STATE_UNAUTHENTICATED] = "unauthenticated",
 163                 [USB_STATE_DEFAULT] = "default",
 164                 [USB_STATE_ADDRESS] = "addressed",
 165                 [USB_STATE_CONFIGURED] = "configured",
 166                 [USB_STATE_SUSPENDED] = "suspended",
 167         };
 168
 169         if (state < 0 || state >= ARRAY_SIZE(names))
 170                 return "UNKNOWN";
 171
 172         return names[state];
 173 }
 174 EXPORT_SYMBOL_GPL(usb_state_string);
 175
 176 static const char *const usb_dr_modes[] = {
 177         [USB_DR_MODE_UNKNOWN]           = "",
 178         [USB_DR_MODE_HOST]              = "host",
 179         [USB_DR_MODE_PERIPHERAL]        = "peripheral",
 180         [USB_DR_MODE_OTG]               = "otg",
 181 };
 182
 183 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
 184 {
 185         int ret;
 186
 187         ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
 188         return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
 189 }
 190
 191 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
 192 {
 193         const char *dr_mode;
 194         int err;
 195
 196         err = device_property_read_string(dev, "dr_mode", &dr_mode);
 197         if (err < 0)
 198                 return USB_DR_MODE_UNKNOWN;
 199
 200         return usb_get_dr_mode_from_string(dr_mode);
 201 }
 202 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
 203
 204 /**
 205  * usb_get_role_switch_default_mode - Get default mode for given device
 206  * @dev: Pointer to the given device
 207  *
 208  * The function gets string from property 'role-switch-default-mode',
 209  * and returns the corresponding enum usb_dr_mode.
 210  */
 211 enum usb_dr_mode usb_get_role_switch_default_mode(struct device *dev)
 212 {
 213         const char *str;
 214         int ret;
 215
 216         ret = device_property_read_string(dev, "role-switch-default-mode", &str);
 217         if (ret < 0)
 218                 return USB_DR_MODE_UNKNOWN;
 219
 220         return usb_get_dr_mode_from_string(str);
 221 }
 222 EXPORT_SYMBOL_GPL(usb_get_role_switch_default_mode);
 223
 224 /**
 225  * usb_decode_interval - Decode bInterval into the time expressed in 1us unit
 226  * @epd: The descriptor of the endpoint
 227  * @speed: The speed that the endpoint works as
 228  *
 229  * Function returns the interval expressed in 1us unit for servicing
 230  * endpoint for data transfers.
 231  */
 232 unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
 233                                  enum usb_device_speed speed)
 234 {
 235         unsigned int interval = 0;
 236
 237         switch (usb_endpoint_type(epd)) {
 238         case USB_ENDPOINT_XFER_CONTROL:
 239                 /* uframes per NAK */
 240                 if (speed == USB_SPEED_HIGH)
 241                         interval = epd->bInterval;
 242                 break;
 243         case USB_ENDPOINT_XFER_ISOC:
 244                 interval = 1 << (epd->bInterval - 1);
 245                 break;
 246         case USB_ENDPOINT_XFER_BULK:
 247                 /* uframes per NAK */
 248                 if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
 249                         interval = epd->bInterval;
 250                 break;
 251         case USB_ENDPOINT_XFER_INT:
 252                 if (speed >= USB_SPEED_HIGH)
 253                         interval = 1 << (epd->bInterval - 1);
 254                 else
 255                         interval = epd->bInterval;
 256                 break;
 257         }
 258
 259         interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;
 260
 261         return interval;
 262 }
 263 EXPORT_SYMBOL_GPL(usb_decode_interval);
 264
 265 #ifdef CONFIG_OF
 266 /**
 267  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
 268  * which is associated with the given phy device_node
 269  * @np: Pointer to the given phy device_node
 270  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
 271  *        phys which do not have phy-cells
 272  *
 273  * In dts a usb controller associates with phy devices.  The function gets
 274  * the string from property 'dr_mode' of the controller associated with the
 275  * given phy device node, and returns the correspondig enum usb_dr_mode.
 276  */
 277 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
 278 {
 279         struct device_node *controller = NULL;
 280         struct of_phandle_args args;
 281         const char *dr_mode;
 282         int index;
 283         int err;
 284
 285         do {
 286                 controller = of_find_node_with_property(controller, "phys");
 287                 if (!of_device_is_available(controller))
 288                         continue;
 289                 index = 0;
 290                 do {
 291                         if (arg0 == -1) {
 292                                 args.np = of_parse_phandle(controller, "phys",
 293                                                         index);
 294                                 args.args_count = 0;
 295                         } else {
 296                                 err = of_parse_phandle_with_args(controller,
 297                                                         "phys", "#phy-cells",
 298                                                         index, &args);
 299                                 if (err)
 300                                         break;
 301                         }
 302
 303                         of_node_put(args.np);
 304                         if (args.np == np && (args.args_count == 0 ||
 305                                               args.args[0] == arg0))
 306                                 goto finish;
 307                         index++;
 308                 } while (args.np);
 309         } while (controller);
 310
 311 finish:
 312         err = of_property_read_string(controller, "dr_mode", &dr_mode);
 313         of_node_put(controller);
 314
 315         if (err < 0)
 316                 return USB_DR_MODE_UNKNOWN;
 317
 318         return usb_get_dr_mode_from_string(dr_mode);
 319 }
 320 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
 321
 322 /**
 323  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 324  * for given targeted hosts (non-PC hosts)
 325  * @np: Pointer to the given device_node
 326  *
 327  * The function gets if the targeted hosts support TPL or not
 328  */
 329 bool of_usb_host_tpl_support(struct device_node *np)
 330 {
 331         return of_property_read_bool(np, "tpl-support");
 332 }
 333 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
 334
 335 /**
 336  * of_usb_update_otg_caps - to update usb otg capabilities according to
 337  * the passed properties in DT.
 338  * @np: Pointer to the given device_node
 339  * @otg_caps: Pointer to the target usb_otg_caps to be set
 340  *
 341  * The function updates the otg capabilities
 342  */
 343 int of_usb_update_otg_caps(struct device_node *np,
 344                         struct usb_otg_caps *otg_caps)
 345 {
 346         u32 otg_rev;
 347
 348         if (!otg_caps)
 349                 return -EINVAL;
 350
 351         if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
 352                 switch (otg_rev) {
 353                 case 0x0100:
 354                 case 0x0120:
 355                 case 0x0130:
 356                 case 0x0200:
 357                         /* Choose the lesser one if it's already been set */
 358                         if (otg_caps->otg_rev)
 359                                 otg_caps->otg_rev = min_t(u16, otg_rev,
 360                                                         otg_caps->otg_rev);
 361                         else
 362                                 otg_caps->otg_rev = otg_rev;
 363                         break;
 364                 default:
 365                         pr_err("%pOF: unsupported otg-rev: 0x%x\n",
 366                                                 np, otg_rev);
 367                         return -EINVAL;
 368                 }
 369         } else {
 370                 /*
 371                  * otg-rev is mandatory for otg properties, if not passed
 372                  * we set it to be 0 and assume it's a legacy otg device.
 373                  * Non-dt platform can set it afterwards.
 374                  */
 375                 otg_caps->otg_rev = 0;
 376         }
 377
 378         if (of_property_read_bool(np, "hnp-disable"))
 379                 otg_caps->hnp_support = false;
 380         if (of_property_read_bool(np, "srp-disable"))
 381                 otg_caps->srp_support = false;
 382         if (of_property_read_bool(np, "adp-disable") ||
 383                                 (otg_caps->otg_rev < 0x0200))
 384                 otg_caps->adp_support = false;
 385
 386         return 0;
 387 }
 388 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
 389
 390 /**
 391  * usb_of_get_companion_dev - Find the companion device
 392  * @dev: the device pointer to find a companion
 393  *
 394  * Find the companion device from platform bus.
 395  *
 396  * Takes a reference to the returned struct device which needs to be dropped
 397  * after use.
 398  *
 399  * Return: On success, a pointer to the companion device, %NULL on failure.
 400  */
 401 struct device *usb_of_get_companion_dev(struct device *dev)
 402 {
 403         struct device_node *node;
 404         struct platform_device *pdev = NULL;
 405
 406         node = of_parse_phandle(dev->of_node, "companion", 0);
 407         if (node)
 408                 pdev = of_find_device_by_node(node);
 409
 410         of_node_put(node);
 411
 412         return pdev ? &pdev->dev : NULL;
 413 }
 414 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
 415 #endif
 416
 417 struct dentry *usb_debug_root;
 418 EXPORT_SYMBOL_GPL(usb_debug_root);
 419
 420 static int __init usb_common_init(void)
 421 {
 422         usb_debug_root = debugfs_create_dir("usb", NULL);
 423         ledtrig_usb_init();
 424         return 0;
 425 }
 426
 427 static void __exit usb_common_exit(void)
 428 {
 429         ledtrig_usb_exit();
 430         debugfs_remove_recursive(usb_debug_root);
 431 }
 432
 433 subsys_initcall(usb_common_init);
 434 module_exit(usb_common_exit);
 435
 436 MODULE_LICENSE("GPL");