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
  19 const char *usb_otg_state_string(enum usb_otg_state state)
  20 {
  21         static const char *const names[] = {
  22                 [OTG_STATE_A_IDLE] = "a_idle",
  23                 [OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
  24                 [OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
  25                 [OTG_STATE_A_HOST] = "a_host",
  26                 [OTG_STATE_A_SUSPEND] = "a_suspend",
  27                 [OTG_STATE_A_PERIPHERAL] = "a_peripheral",
  28                 [OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
  29                 [OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
  30                 [OTG_STATE_B_IDLE] = "b_idle",
  31                 [OTG_STATE_B_SRP_INIT] = "b_srp_init",
  32                 [OTG_STATE_B_PERIPHERAL] = "b_peripheral",
  33                 [OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
  34                 [OTG_STATE_B_HOST] = "b_host",
  35         };
  36
  37         if (state < 0 || state >= ARRAY_SIZE(names))
  38                 return "UNDEFINED";
  39
  40         return names[state];
  41 }
  42 EXPORT_SYMBOL_GPL(usb_otg_state_string);
  43
  44 static const char *const speed_names[] = {
  45         [USB_SPEED_UNKNOWN] = "UNKNOWN",
  46         [USB_SPEED_LOW] = "low-speed",
  47         [USB_SPEED_FULL] = "full-speed",
  48         [USB_SPEED_HIGH] = "high-speed",
  49         [USB_SPEED_WIRELESS] = "wireless",
  50         [USB_SPEED_SUPER] = "super-speed",
  51         [USB_SPEED_SUPER_PLUS] = "super-speed-plus",
  52 };
  53
  54 const char *usb_speed_string(enum usb_device_speed speed)
  55 {
  56         if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
  57                 speed = USB_SPEED_UNKNOWN;
  58         return speed_names[speed];
  59 }
  60 EXPORT_SYMBOL_GPL(usb_speed_string);
  61
  62 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
  63 {
  64         const char *maximum_speed;
  65         int ret;
  66
  67         ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
  68         if (ret < 0)
  69                 return USB_SPEED_UNKNOWN;
  70
  71         ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
  72
  73         return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
  74 }
  75 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
  76
  77 const char *usb_state_string(enum usb_device_state state)
  78 {
  79         static const char *const names[] = {
  80                 [USB_STATE_NOTATTACHED] = "not attached",
  81                 [USB_STATE_ATTACHED] = "attached",
  82                 [USB_STATE_POWERED] = "powered",
  83                 [USB_STATE_RECONNECTING] = "reconnecting",
  84                 [USB_STATE_UNAUTHENTICATED] = "unauthenticated",
  85                 [USB_STATE_DEFAULT] = "default",
  86                 [USB_STATE_ADDRESS] = "addressed",
  87                 [USB_STATE_CONFIGURED] = "configured",
  88                 [USB_STATE_SUSPENDED] = "suspended",
  89         };
  90
  91         if (state < 0 || state >= ARRAY_SIZE(names))
  92                 return "UNKNOWN";
  93
  94         return names[state];
  95 }
  96 EXPORT_SYMBOL_GPL(usb_state_string);
  97
  98 static const char *const usb_dr_modes[] = {
  99         [USB_DR_MODE_UNKNOWN]           = "",
 100         [USB_DR_MODE_HOST]              = "host",
 101         [USB_DR_MODE_PERIPHERAL]        = "peripheral",
 102         [USB_DR_MODE_OTG]               = "otg",
 103 };
 104
 105 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
 106 {
 107         int ret;
 108
 109         ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
 110         return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
 111 }
 112
 113 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
 114 {
 115         const char *dr_mode;
 116         int err;
 117
 118         err = device_property_read_string(dev, "dr_mode", &dr_mode);
 119         if (err < 0)
 120                 return USB_DR_MODE_UNKNOWN;
 121
 122         return usb_get_dr_mode_from_string(dr_mode);
 123 }
 124 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
 125
 126 #ifdef CONFIG_OF
 127 /**
 128  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
 129  * which is associated with the given phy device_node
 130  * @np: Pointer to the given phy device_node
 131  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
 132  *        phys which do not have phy-cells
 133  *
 134  * In dts a usb controller associates with phy devices.  The function gets
 135  * the string from property 'dr_mode' of the controller associated with the
 136  * given phy device node, and returns the correspondig enum usb_dr_mode.
 137  */
 138 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
 139 {
 140         struct device_node *controller = NULL;
 141         struct of_phandle_args args;
 142         const char *dr_mode;
 143         int index;
 144         int err;
 145
 146         do {
 147                 controller = of_find_node_with_property(controller, "phys");
 148                 if (!of_device_is_available(controller))
 149                         continue;
 150                 index = 0;
 151                 do {
 152                         if (arg0 == -1) {
 153                                 args.np = of_parse_phandle(controller, "phys",
 154                                                         index);
 155                                 args.args_count = 0;
 156                         } else {
 157                                 err = of_parse_phandle_with_args(controller,
 158                                                         "phys", "#phy-cells",
 159                                                         index, &args);
 160                                 if (err)
 161                                         break;
 162                         }
 163
 164                         of_node_put(args.np);
 165                         if (args.np == np && (args.args_count == 0 ||
 166                                               args.args[0] == arg0))
 167                                 goto finish;
 168                         index++;
 169                 } while (args.np);
 170         } while (controller);
 171
 172 finish:
 173         err = of_property_read_string(controller, "dr_mode", &dr_mode);
 174         of_node_put(controller);
 175
 176         if (err < 0)
 177                 return USB_DR_MODE_UNKNOWN;
 178
 179         return usb_get_dr_mode_from_string(dr_mode);
 180 }
 181 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
 182
 183 /**
 184  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 185  * for given targeted hosts (non-PC hosts)
 186  * @np: Pointer to the given device_node
 187  *
 188  * The function gets if the targeted hosts support TPL or not
 189  */
 190 bool of_usb_host_tpl_support(struct device_node *np)
 191 {
 192         return of_property_read_bool(np, "tpl-support");
 193 }
 194 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
 195
 196 /**
 197  * of_usb_update_otg_caps - to update usb otg capabilities according to
 198  * the passed properties in DT.
 199  * @np: Pointer to the given device_node
 200  * @otg_caps: Pointer to the target usb_otg_caps to be set
 201  *
 202  * The function updates the otg capabilities
 203  */
 204 int of_usb_update_otg_caps(struct device_node *np,
 205                         struct usb_otg_caps *otg_caps)
 206 {
 207         u32 otg_rev;
 208
 209         if (!otg_caps)
 210                 return -EINVAL;
 211
 212         if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
 213                 switch (otg_rev) {
 214                 case 0x0100:
 215                 case 0x0120:
 216                 case 0x0130:
 217                 case 0x0200:
 218                         /* Choose the lesser one if it's already been set */
 219                         if (otg_caps->otg_rev)
 220                                 otg_caps->otg_rev = min_t(u16, otg_rev,
 221                                                         otg_caps->otg_rev);
 222                         else
 223                                 otg_caps->otg_rev = otg_rev;
 224                         break;
 225                 default:
 226                         pr_err("%pOF: unsupported otg-rev: 0x%x\n",
 227                                                 np, otg_rev);
 228                         return -EINVAL;
 229                 }
 230         } else {
 231                 /*
 232                  * otg-rev is mandatory for otg properties, if not passed
 233                  * we set it to be 0 and assume it's a legacy otg device.
 234                  * Non-dt platform can set it afterwards.
 235                  */
 236                 otg_caps->otg_rev = 0;
 237         }
 238
 239         if (of_property_read_bool(np, "hnp-disable"))
 240                 otg_caps->hnp_support = false;
 241         if (of_property_read_bool(np, "srp-disable"))
 242                 otg_caps->srp_support = false;
 243         if (of_property_read_bool(np, "adp-disable") ||
 244                                 (otg_caps->otg_rev < 0x0200))
 245                 otg_caps->adp_support = false;
 246
 247         return 0;
 248 }
 249 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
 250
 251 /**
 252  * usb_of_get_companion_dev - Find the companion device
 253  * @dev: the device pointer to find a companion
 254  *
 255  * Find the companion device from platform bus.
 256  *
 257  * Takes a reference to the returned struct device which needs to be dropped
 258  * after use.
 259  *
 260  * Return: On success, a pointer to the companion device, %NULL on failure.
 261  */
 262 struct device *usb_of_get_companion_dev(struct device *dev)
 263 {
 264         struct device_node *node;
 265         struct platform_device *pdev = NULL;
 266
 267         node = of_parse_phandle(dev->of_node, "companion", 0);
 268         if (node)
 269                 pdev = of_find_device_by_node(node);
 270
 271         of_node_put(node);
 272
 273         return pdev ? &pdev->dev : NULL;
 274 }
 275 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
 276 #endif
 277
 278 MODULE_LICENSE("GPL");