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
  28const char *usb_ep_type_string(int ep_type)
  29{
  30        if (ep_type < 0 || ep_type >= ARRAY_SIZE(ep_type_names))
  31                return "unknown";
  32
  33        return ep_type_names[ep_type];
  34}
  35EXPORT_SYMBOL_GPL(usb_ep_type_string);
  36
  37const char *usb_otg_state_string(enum usb_otg_state state)
  38{
  39        static const char *const names[] = {
  40                [OTG_STATE_A_IDLE] = "a_idle",
  41                [OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
  42                [OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
  43                [OTG_STATE_A_HOST] = "a_host",
  44                [OTG_STATE_A_SUSPEND] = "a_suspend",
  45                [OTG_STATE_A_PERIPHERAL] = "a_peripheral",
  46                [OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
  47                [OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
  48                [OTG_STATE_B_IDLE] = "b_idle",
  49                [OTG_STATE_B_SRP_INIT] = "b_srp_init",
  50                [OTG_STATE_B_PERIPHERAL] = "b_peripheral",
  51                [OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
  52                [OTG_STATE_B_HOST] = "b_host",
  53        };
  54
  55        if (state < 0 || state >= ARRAY_SIZE(names))
  56                return "UNDEFINED";
  57
  58        return names[state];
  59}
  60EXPORT_SYMBOL_GPL(usb_otg_state_string);
  61
  62static const char *const speed_names[] = {
  63        [USB_SPEED_UNKNOWN] = "UNKNOWN",
  64        [USB_SPEED_LOW] = "low-speed",
  65        [USB_SPEED_FULL] = "full-speed",
  66        [USB_SPEED_HIGH] = "high-speed",
  67        [USB_SPEED_WIRELESS] = "wireless",
  68        [USB_SPEED_SUPER] = "super-speed",
  69        [USB_SPEED_SUPER_PLUS] = "super-speed-plus",
  70};
  71
  72const char *usb_speed_string(enum usb_device_speed speed)
  73{
  74        if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
  75                speed = USB_SPEED_UNKNOWN;
  76        return speed_names[speed];
  77}
  78EXPORT_SYMBOL_GPL(usb_speed_string);
  79
  80enum usb_device_speed usb_get_maximum_speed(struct device *dev)
  81{
  82        const char *maximum_speed;
  83        int ret;
  84
  85        ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
  86        if (ret < 0)
  87                return USB_SPEED_UNKNOWN;
  88
  89        ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
  90
  91        return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
  92}
  93EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
  94
  95const char *usb_state_string(enum usb_device_state state)
  96{
  97        static const char *const names[] = {
  98                [USB_STATE_NOTATTACHED] = "not attached",
  99                [USB_STATE_ATTACHED] = "attached",
 100                [USB_STATE_POWERED] = "powered",
 101                [USB_STATE_RECONNECTING] = "reconnecting",
 102                [USB_STATE_UNAUTHENTICATED] = "unauthenticated",
 103                [USB_STATE_DEFAULT] = "default",
 104                [USB_STATE_ADDRESS] = "addressed",
 105                [USB_STATE_CONFIGURED] = "configured",
 106                [USB_STATE_SUSPENDED] = "suspended",
 107        };
 108
 109        if (state < 0 || state >= ARRAY_SIZE(names))
 110                return "UNKNOWN";
 111
 112        return names[state];
 113}
 114EXPORT_SYMBOL_GPL(usb_state_string);
 115
 116static const char *const usb_dr_modes[] = {
 117        [USB_DR_MODE_UNKNOWN]           = "",
 118        [USB_DR_MODE_HOST]              = "host",
 119        [USB_DR_MODE_PERIPHERAL]        = "peripheral",
 120        [USB_DR_MODE_OTG]               = "otg",
 121};
 122
 123static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
 124{
 125        int ret;
 126
 127        ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
 128        return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
 129}
 130
 131enum usb_dr_mode usb_get_dr_mode(struct device *dev)
 132{
 133        const char *dr_mode;
 134        int err;
 135
 136        err = device_property_read_string(dev, "dr_mode", &dr_mode);
 137        if (err < 0)
 138                return USB_DR_MODE_UNKNOWN;
 139
 140        return usb_get_dr_mode_from_string(dr_mode);
 141}
 142EXPORT_SYMBOL_GPL(usb_get_dr_mode);
 143
 144#ifdef CONFIG_OF
 145/**
 146 * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
 147 * which is associated with the given phy device_node
 148 * @np: Pointer to the given phy device_node
 149 * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
 150 *        phys which do not have phy-cells
 151 *
 152 * In dts a usb controller associates with phy devices.  The function gets
 153 * the string from property 'dr_mode' of the controller associated with the
 154 * given phy device node, and returns the correspondig enum usb_dr_mode.
 155 */
 156enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
 157{
 158        struct device_node *controller = NULL;
 159        struct of_phandle_args args;
 160        const char *dr_mode;
 161        int index;
 162        int err;
 163
 164        do {
 165                controller = of_find_node_with_property(controller, "phys");
 166                if (!of_device_is_available(controller))
 167                        continue;
 168                index = 0;
 169                do {
 170                        if (arg0 == -1) {
 171                                args.np = of_parse_phandle(controller, "phys",
 172                                                        index);
 173                                args.args_count = 0;
 174                        } else {
 175                                err = of_parse_phandle_with_args(controller,
 176                                                        "phys", "#phy-cells",
 177                                                        index, &args);
 178                                if (err)
 179                                        break;
 180                        }
 181
 182                        of_node_put(args.np);
 183                        if (args.np == np && (args.args_count == 0 ||
 184                                              args.args[0] == arg0))
 185                                goto finish;
 186                        index++;
 187                } while (args.np);
 188        } while (controller);
 189
 190finish:
 191        err = of_property_read_string(controller, "dr_mode", &dr_mode);
 192        of_node_put(controller);
 193
 194        if (err < 0)
 195                return USB_DR_MODE_UNKNOWN;
 196
 197        return usb_get_dr_mode_from_string(dr_mode);
 198}
 199EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
 200
 201/**
 202 * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 203 * for given targeted hosts (non-PC hosts)
 204 * @np: Pointer to the given device_node
 205 *
 206 * The function gets if the targeted hosts support TPL or not
 207 */
 208bool of_usb_host_tpl_support(struct device_node *np)
 209{
 210        return of_property_read_bool(np, "tpl-support");
 211}
 212EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
 213
 214/**
 215 * of_usb_update_otg_caps - to update usb otg capabilities according to
 216 * the passed properties in DT.
 217 * @np: Pointer to the given device_node
 218 * @otg_caps: Pointer to the target usb_otg_caps to be set
 219 *
 220 * The function updates the otg capabilities
 221 */
 222int of_usb_update_otg_caps(struct device_node *np,
 223                        struct usb_otg_caps *otg_caps)
 224{
 225        u32 otg_rev;
 226
 227        if (!otg_caps)
 228                return -EINVAL;
 229
 230        if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
 231                switch (otg_rev) {
 232                case 0x0100:
 233                case 0x0120:
 234                case 0x0130:
 235                case 0x0200:
 236                        /* Choose the lesser one if it's already been set */
 237                        if (otg_caps->otg_rev)
 238                                otg_caps->otg_rev = min_t(u16, otg_rev,
 239                                                        otg_caps->otg_rev);
 240                        else
 241                                otg_caps->otg_rev = otg_rev;
 242                        break;
 243                default:
 244                        pr_err("%pOF: unsupported otg-rev: 0x%x\n",
 245                                                np, otg_rev);
 246                        return -EINVAL;
 247                }
 248        } else {
 249                /*
 250                 * otg-rev is mandatory for otg properties, if not passed
 251                 * we set it to be 0 and assume it's a legacy otg device.
 252                 * Non-dt platform can set it afterwards.
 253                 */
 254                otg_caps->otg_rev = 0;
 255        }
 256
 257        if (of_property_read_bool(np, "hnp-disable"))
 258                otg_caps->hnp_support = false;
 259        if (of_property_read_bool(np, "srp-disable"))
 260                otg_caps->srp_support = false;
 261        if (of_property_read_bool(np, "adp-disable") ||
 262                                (otg_caps->otg_rev < 0x0200))
 263                otg_caps->adp_support = false;
 264
 265        return 0;
 266}
 267EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
 268
 269/**
 270 * usb_of_get_companion_dev - Find the companion device
 271 * @dev: the device pointer to find a companion
 272 *
 273 * Find the companion device from platform bus.
 274 *
 275 * Takes a reference to the returned struct device which needs to be dropped
 276 * after use.
 277 *
 278 * Return: On success, a pointer to the companion device, %NULL on failure.
 279 */
 280struct device *usb_of_get_companion_dev(struct device *dev)
 281{
 282        struct device_node *node;
 283        struct platform_device *pdev = NULL;
 284
 285        node = of_parse_phandle(dev->of_node, "companion", 0);
 286        if (node)
 287                pdev = of_find_device_by_node(node);
 288
 289        of_node_put(node);
 290
 291        return pdev ? &pdev->dev : NULL;
 292}
 293EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
 294#endif
 295
 296struct dentry *usb_debug_root;
 297EXPORT_SYMBOL_GPL(usb_debug_root);
 298
 299static int __init usb_common_init(void)
 300{
 301        usb_debug_root = debugfs_create_dir("usb", NULL);
 302        ledtrig_usb_init();
 303        return 0;
 304}
 305
 306static void __exit usb_common_exit(void)
 307{
 308        ledtrig_usb_exit();
 309        debugfs_remove_recursive(usb_debug_root);
 310}
 311
 312subsys_initcall(usb_common_init);
 313module_exit(usb_common_exit);
 314
 315MODULE_LICENSE("GPL");
 316