LXR linux/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
  21static 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 */
  34const 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}
  41EXPORT_SYMBOL_GPL(usb_ep_type_string);
  42
  43const 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}
  66EXPORT_SYMBOL_GPL(usb_otg_state_string);
  67
  68static 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
  78static 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 */
  91const 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}
  97EXPORT_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 */
 107enum 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}
 123EXPORT_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 */
 134enum 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}
 146EXPORT_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 */
 154const 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}
 173EXPORT_SYMBOL_GPL(usb_state_string);
 174
 175static 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
 182static 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
 190enum 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}
 201EXPORT_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 */
 211unsigned 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}
 242EXPORT_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 */
 256enum 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
 290finish:
 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}
 299EXPORT_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 */
 308bool of_usb_host_tpl_support(struct device_node *np)
 309{
 310        return of_property_read_bool(np, "tpl-support");
 311}
 312EXPORT_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 */
 322int 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}
 367EXPORT_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 */
 380struct 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}
 393EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
 394#endif
 395
 396struct dentry *usb_debug_root;
 397EXPORT_SYMBOL_GPL(usb_debug_root);
 398
 399static 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
 406static void __exit usb_common_exit(void)
 407{
 408        ledtrig_usb_exit();
 409        debugfs_remove_recursive(usb_debug_root);
 410}
 411
 412subsys_initcall(usb_common_init);
 413module_exit(usb_common_exit);
 414
 415MODULE_LICENSE("GPL");
 416