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/usb/ch9.h>
  15 #include <linux/usb/of.h>
  16 #include <linux/usb/otg.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/debugfs.h>
  19 #include "common.h"
  20
  21 static const char *const ep_type_names[] = {
  22         [USB_ENDPOINT_XFER_CONTROL] = "ctrl",
  23         [USB_ENDPOINT_XFER_ISOC] = "isoc",
  24         [USB_ENDPOINT_XFER_BULK] = "bulk",
  25         [USB_ENDPOINT_XFER_INT] = "intr",
  26 };
  27
  28 /**
  29  * usb_ep_type_string() - Returns human readable-name of the endpoint type.
  30  * @ep_type: The endpoint type to return human-readable name for.  If it's not
  31  *   any of the types: USB_ENDPOINT_XFER_{CONTROL, ISOC, BULK, INT},
  32  *   usually got by usb_endpoint_type(), the string 'unknown' will be returned.
  33  */
  34 const char *usb_ep_type_string(int ep_type)
  35 {
  36         if (ep_type < 0 || ep_type >= ARRAY_SIZE(ep_type_names))
  37                 return "unknown";
  38
  39         return ep_type_names[ep_type];
  40 }
  41 EXPORT_SYMBOL_GPL(usb_ep_type_string);
  42
  43 const char *usb_otg_state_string(enum usb_otg_state state)
  44 {
  45         static const char *const names[] = {
  46                 [OTG_STATE_A_IDLE] = "a_idle",
  47                 [OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
  48                 [OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
  49                 [OTG_STATE_A_HOST] = "a_host",
  50                 [OTG_STATE_A_SUSPEND] = "a_suspend",
  51                 [OTG_STATE_A_PERIPHERAL] = "a_peripheral",
  52                 [OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
  53                 [OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
  54                 [OTG_STATE_B_IDLE] = "b_idle",
  55                 [OTG_STATE_B_SRP_INIT] = "b_srp_init",
  56                 [OTG_STATE_B_PERIPHERAL] = "b_peripheral",
  57                 [OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
  58                 [OTG_STATE_B_HOST] = "b_host",
  59         };
  60
  61         if (state < 0 || state >= ARRAY_SIZE(names))
  62                 return "UNDEFINED";
  63
  64         return names[state];
  65 }
  66 EXPORT_SYMBOL_GPL(usb_otg_state_string);
  67
  68 static const char *const speed_names[] = {
  69         [USB_SPEED_UNKNOWN] = "UNKNOWN",
  70         [USB_SPEED_LOW] = "low-speed",
  71         [USB_SPEED_FULL] = "full-speed",
  72         [USB_SPEED_HIGH] = "high-speed",
  73         [USB_SPEED_WIRELESS] = "wireless",
  74         [USB_SPEED_SUPER] = "super-speed",
  75         [USB_SPEED_SUPER_PLUS] = "super-speed-plus",
  76 };
  77
  78 static const char *const ssp_rate[] = {
  79         [USB_SSP_GEN_UNKNOWN] = "UNKNOWN",
  80         [USB_SSP_GEN_2x1] = "super-speed-plus-gen2x1",
  81         [USB_SSP_GEN_1x2] = "super-speed-plus-gen1x2",
  82         [USB_SSP_GEN_2x2] = "super-speed-plus-gen2x2",
  83 };
  84
  85 /**
  86  * usb_speed_string() - Returns human readable-name of the speed.
  87  * @speed: The speed to return human-readable name for.  If it's not
  88  *   any of the speeds defined in usb_device_speed enum, string for
  89  *   USB_SPEED_UNKNOWN will be returned.
  90  */
  91 const char *usb_speed_string(enum usb_device_speed speed)
  92 {
  93         if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
  94                 speed = USB_SPEED_UNKNOWN;
  95         return speed_names[speed];
  96 }
  97 EXPORT_SYMBOL_GPL(usb_speed_string);
  98
  99 /**
 100  * usb_get_maximum_speed - Get maximum requested speed for a given USB
 101  * controller.
 102  * @dev: Pointer to the given USB controller device
 103  *
 104  * The function gets the maximum speed string from property "maximum-speed",
 105  * and returns the corresponding enum usb_device_speed.
 106  */
 107 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
 108 {
 109         const char *maximum_speed;
 110         int ret;
 111
 112         ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
 113         if (ret < 0)
 114                 return USB_SPEED_UNKNOWN;
 115
 116         ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
 117         if (ret > 0)
 118                 return USB_SPEED_SUPER_PLUS;
 119
 120         ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
 121         return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
 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_decode_interval - Decode bInterval into the time expressed in 1us unit
 205  * @epd: The descriptor of the endpoint
 206  * @speed: The speed that the endpoint works as
 207  *
 208  * Function returns the interval expressed in 1us unit for servicing
 209  * endpoint for data transfers.
 210  */
 211 unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
 212                                  enum usb_device_speed speed)
 213 {
 214         unsigned int interval = 0;
 215
 216         switch (usb_endpoint_type(epd)) {
 217         case USB_ENDPOINT_XFER_CONTROL:
 218                 /* uframes per NAK */
 219                 if (speed == USB_SPEED_HIGH)
 220                         interval = epd->bInterval;
 221                 break;
 222         case USB_ENDPOINT_XFER_ISOC:
 223                 interval = 1 << (epd->bInterval - 1);
 224                 break;
 225         case USB_ENDPOINT_XFER_BULK:
 226                 /* uframes per NAK */
 227                 if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
 228                         interval = epd->bInterval;
 229                 break;
 230         case USB_ENDPOINT_XFER_INT:
 231                 if (speed >= USB_SPEED_HIGH)
 232                         interval = 1 << (epd->bInterval - 1);
 233                 else
 234                         interval = epd->bInterval;
 235                 break;
 236         }
 237
 238         interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;
 239
 240         return interval;
 241 }
 242 EXPORT_SYMBOL_GPL(usb_decode_interval);
 243
 244 #ifdef CONFIG_OF
 245 /**
 246  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
 247  * which is associated with the given phy device_node
 248  * @np: Pointer to the given phy device_node
 249  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
 250  *        phys which do not have phy-cells
 251  *
 252  * In dts a usb controller associates with phy devices.  The function gets
 253  * the string from property 'dr_mode' of the controller associated with the
 254  * given phy device node, and returns the correspondig enum usb_dr_mode.
 255  */
 256 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
 257 {
 258         struct device_node *controller = NULL;
 259         struct of_phandle_args args;
 260         const char *dr_mode;
 261         int index;
 262         int err;
 263
 264         do {
 265                 controller = of_find_node_with_property(controller, "phys");
 266                 if (!of_device_is_available(controller))
 267                         continue;
 268                 index = 0;
 269                 do {
 270                         if (arg0 == -1) {
 271                                 args.np = of_parse_phandle(controller, "phys",
 272                                                         index);
 273                                 args.args_count = 0;
 274                         } else {
 275                                 err = of_parse_phandle_with_args(controller,
 276                                                         "phys", "#phy-cells",
 277                                                         index, &args);
 278                                 if (err)
 279                                         break;
 280                         }
 281
 282                         of_node_put(args.np);
 283                         if (args.np == np && (args.args_count == 0 ||
 284                                               args.args[0] == arg0))
 285                                 goto finish;
 286                         index++;
 287                 } while (args.np);
 288         } while (controller);
 289
 290 finish:
 291         err = of_property_read_string(controller, "dr_mode", &dr_mode);
 292         of_node_put(controller);
 293
 294         if (err < 0)
 295                 return USB_DR_MODE_UNKNOWN;
 296
 297         return usb_get_dr_mode_from_string(dr_mode);
 298 }
 299 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
 300
 301 /**
 302  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 303  * for given targeted hosts (non-PC hosts)
 304  * @np: Pointer to the given device_node
 305  *
 306  * The function gets if the targeted hosts support TPL or not
 307  */
 308 bool of_usb_host_tpl_support(struct device_node *np)
 309 {
 310         return of_property_read_bool(np, "tpl-support");
 311 }
 312 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
 313
 314 /**
 315  * of_usb_update_otg_caps - to update usb otg capabilities according to
 316  * the passed properties in DT.
 317  * @np: Pointer to the given device_node
 318  * @otg_caps: Pointer to the target usb_otg_caps to be set
 319  *
 320  * The function updates the otg capabilities
 321  */
 322 int of_usb_update_otg_caps(struct device_node *np,
 323                         struct usb_otg_caps *otg_caps)
 324 {
 325         u32 otg_rev;
 326
 327         if (!otg_caps)
 328                 return -EINVAL;
 329
 330         if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
 331                 switch (otg_rev) {
 332                 case 0x0100:
 333                 case 0x0120:
 334                 case 0x0130:
 335                 case 0x0200:
 336                         /* Choose the lesser one if it's already been set */
 337                         if (otg_caps->otg_rev)
 338                                 otg_caps->otg_rev = min_t(u16, otg_rev,
 339                                                         otg_caps->otg_rev);
 340                         else
 341                                 otg_caps->otg_rev = otg_rev;
 342                         break;
 343                 default:
 344                         pr_err("%pOF: unsupported otg-rev: 0x%x\n",
 345                                                 np, otg_rev);
 346                         return -EINVAL;
 347                 }
 348         } else {
 349                 /*
 350                  * otg-rev is mandatory for otg properties, if not passed
 351                  * we set it to be 0 and assume it's a legacy otg device.
 352                  * Non-dt platform can set it afterwards.
 353                  */
 354                 otg_caps->otg_rev = 0;
 355         }
 356
 357         if (of_property_read_bool(np, "hnp-disable"))
 358                 otg_caps->hnp_support = false;
 359         if (of_property_read_bool(np, "srp-disable"))
 360                 otg_caps->srp_support = false;
 361         if (of_property_read_bool(np, "adp-disable") ||
 362                                 (otg_caps->otg_rev < 0x0200))
 363                 otg_caps->adp_support = false;
 364
 365         return 0;
 366 }
 367 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
 368
 369 /**
 370  * usb_of_get_companion_dev - Find the companion device
 371  * @dev: the device pointer to find a companion
 372  *
 373  * Find the companion device from platform bus.
 374  *
 375  * Takes a reference to the returned struct device which needs to be dropped
 376  * after use.
 377  *
 378  * Return: On success, a pointer to the companion device, %NULL on failure.
 379  */
 380 struct device *usb_of_get_companion_dev(struct device *dev)
 381 {
 382         struct device_node *node;
 383         struct platform_device *pdev = NULL;
 384
 385         node = of_parse_phandle(dev->of_node, "companion", 0);
 386         if (node)
 387                 pdev = of_find_device_by_node(node);
 388
 389         of_node_put(node);
 390
 391         return pdev ? &pdev->dev : NULL;
 392 }
 393 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
 394 #endif
 395
 396 struct dentry *usb_debug_root;
 397 EXPORT_SYMBOL_GPL(usb_debug_root);
 398
 399 static int __init usb_common_init(void)
 400 {
 401         usb_debug_root = debugfs_create_dir("usb", NULL);
 402         ledtrig_usb_init();
 403         return 0;
 404 }
 405
 406 static void __exit usb_common_exit(void)
 407 {
 408         ledtrig_usb_exit();
 409         debugfs_remove_recursive(usb_debug_root);
 410 }
 411
 412 subsys_initcall(usb_common_init);
 413 module_exit(usb_common_exit);
 414
 415 MODULE_LICENSE("GPL");