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 const 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 }
  35 EXPORT_SYMBOL_GPL(usb_ep_type_string);
  36
  37 const 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 }
  60 EXPORT_SYMBOL_GPL(usb_otg_state_string);
  61
  62 static 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
  72 const 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 }
  78 EXPORT_SYMBOL_GPL(usb_speed_string);
  79
  80 enum 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 }
  93 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
  94
  95 const 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 }
 114 EXPORT_SYMBOL_GPL(usb_state_string);
 115
 116 static 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
 123 static 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
 131 enum 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 }
 142 EXPORT_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  */
 156 enum 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
 190 finish:
 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 }
 199 EXPORT_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  */
 208 bool of_usb_host_tpl_support(struct device_node *np)
 209 {
 210         return of_property_read_bool(np, "tpl-support");
 211 }
 212 EXPORT_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  */
 222 int 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 }
 267 EXPORT_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  */
 280 struct 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 }
 293 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
 294 #endif
 295
 296 struct dentry *usb_debug_root;
 297 EXPORT_SYMBOL_GPL(usb_debug_root);
 298
 299 static 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
 306 static void __exit usb_common_exit(void)
 307 {
 308         ledtrig_usb_exit();
 309         debugfs_remove_recursive(usb_debug_root);
 310 }
 311
 312 subsys_initcall(usb_common_init);
 313 module_exit(usb_common_exit);
 314
 315 MODULE_LICENSE("GPL");