drivers/usb/common/common.c

   1 /*
   2  * Provides code common for host and device side USB.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation, version 2.
   7  *
   8  * If either host side (ie. CONFIG_USB=y) or device side USB stack
   9  * (ie. CONFIG_USB_GADGET=y) is compiled in the kernel, this module is
  10  * compiled-in as well.  Otherwise, if either of the two stacks is
  11  * compiled as module, this file is compiled as module as well.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/usb/ch9.h>
  18 #include <linux/usb/of.h>
  19 #include <linux/usb/otg.h>
  20 #include <linux/of_platform.h>
  21
  22 const char *usb_otg_state_string(enum usb_otg_state state)
  23 {
  24         static const char *const names[] = {
  25                 [OTG_STATE_A_IDLE] = "a_idle",
  26                 [OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
  27                 [OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
  28                 [OTG_STATE_A_HOST] = "a_host",
  29                 [OTG_STATE_A_SUSPEND] = "a_suspend",
  30                 [OTG_STATE_A_PERIPHERAL] = "a_peripheral",
  31                 [OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
  32                 [OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
  33                 [OTG_STATE_B_IDLE] = "b_idle",
  34                 [OTG_STATE_B_SRP_INIT] = "b_srp_init",
  35                 [OTG_STATE_B_PERIPHERAL] = "b_peripheral",
  36                 [OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
  37                 [OTG_STATE_B_HOST] = "b_host",
  38         };
  39
  40         if (state < 0 || state >= ARRAY_SIZE(names))
  41                 return "UNDEFINED";
  42
  43         return names[state];
  44 }
  45 EXPORT_SYMBOL_GPL(usb_otg_state_string);
  46
  47 static const char *const speed_names[] = {
  48         [USB_SPEED_UNKNOWN] = "UNKNOWN",
  49         [USB_SPEED_LOW] = "low-speed",
  50         [USB_SPEED_FULL] = "full-speed",
  51         [USB_SPEED_HIGH] = "high-speed",
  52         [USB_SPEED_WIRELESS] = "wireless",
  53         [USB_SPEED_SUPER] = "super-speed",
  54         [USB_SPEED_SUPER_PLUS] = "super-speed-plus",
  55 };
  56
  57 const char *usb_speed_string(enum usb_device_speed speed)
  58 {
  59         if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
  60                 speed = USB_SPEED_UNKNOWN;
  61         return speed_names[speed];
  62 }
  63 EXPORT_SYMBOL_GPL(usb_speed_string);
  64
  65 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
  66 {
  67         const char *maximum_speed;
  68         int err;
  69         int i;
  70
  71         err = device_property_read_string(dev, "maximum-speed", &maximum_speed);
  72         if (err < 0)
  73                 return USB_SPEED_UNKNOWN;
  74
  75         for (i = 0; i < ARRAY_SIZE(speed_names); i++)
  76                 if (strcmp(maximum_speed, speed_names[i]) == 0)
  77                         return i;
  78
  79         return USB_SPEED_UNKNOWN;
  80 }
  81 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
  82
  83 const char *usb_state_string(enum usb_device_state state)
  84 {
  85         static const char *const names[] = {
  86                 [USB_STATE_NOTATTACHED] = "not attached",
  87                 [USB_STATE_ATTACHED] = "attached",
  88                 [USB_STATE_POWERED] = "powered",
  89                 [USB_STATE_RECONNECTING] = "reconnecting",
  90                 [USB_STATE_UNAUTHENTICATED] = "unauthenticated",
  91                 [USB_STATE_DEFAULT] = "default",
  92                 [USB_STATE_ADDRESS] = "addressed",
  93                 [USB_STATE_CONFIGURED] = "configured",
  94                 [USB_STATE_SUSPENDED] = "suspended",
  95         };
  96
  97         if (state < 0 || state >= ARRAY_SIZE(names))
  98                 return "UNKNOWN";
  99
 100         return names[state];
 101 }
 102 EXPORT_SYMBOL_GPL(usb_state_string);
 103
 104 static const char *const usb_dr_modes[] = {
 105         [USB_DR_MODE_UNKNOWN]           = "",
 106         [USB_DR_MODE_HOST]              = "host",
 107         [USB_DR_MODE_PERIPHERAL]        = "peripheral",
 108         [USB_DR_MODE_OTG]               = "otg",
 109 };
 110
 111 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
 112 {
 113         int i;
 114
 115         for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
 116                 if (!strcmp(usb_dr_modes[i], str))
 117                         return i;
 118
 119         return USB_DR_MODE_UNKNOWN;
 120 }
 121
 122 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
 123 {
 124         const char *dr_mode;
 125         int err;
 126
 127         err = device_property_read_string(dev, "dr_mode", &dr_mode);
 128         if (err < 0)
 129                 return USB_DR_MODE_UNKNOWN;
 130
 131         return usb_get_dr_mode_from_string(dr_mode);
 132 }
 133 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
 134
 135 #ifdef CONFIG_OF
 136 /**
 137  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
 138  * which is associated with the given phy device_node
 139  * @np: Pointer to the given phy device_node
 140  *
 141  * In dts a usb controller associates with phy devices.  The function gets
 142  * the string from property 'dr_mode' of the controller associated with the
 143  * given phy device node, and returns the correspondig enum usb_dr_mode.
 144  */
 145 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
 146 {
 147         struct device_node *controller = NULL;
 148         struct device_node *phy;
 149         const char *dr_mode;
 150         int index;
 151         int err;
 152
 153         do {
 154                 controller = of_find_node_with_property(controller, "phys");
 155                 index = 0;
 156                 do {
 157                         phy = of_parse_phandle(controller, "phys", index);
 158                         of_node_put(phy);
 159                         if (phy == phy_np)
 160                                 goto finish;
 161                         index++;
 162                 } while (phy);
 163         } while (controller);
 164
 165 finish:
 166         err = of_property_read_string(controller, "dr_mode", &dr_mode);
 167         of_node_put(controller);
 168
 169         if (err < 0)
 170                 return USB_DR_MODE_UNKNOWN;
 171
 172         return usb_get_dr_mode_from_string(dr_mode);
 173 }
 174 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
 175
 176 /**
 177  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 178  * for given targeted hosts (non-PC hosts)
 179  * @np: Pointer to the given device_node
 180  *
 181  * The function gets if the targeted hosts support TPL or not
 182  */
 183 bool of_usb_host_tpl_support(struct device_node *np)
 184 {
 185         if (of_find_property(np, "tpl-support", NULL))
 186                 return true;
 187
 188         return false;
 189 }
 190 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
 191
 192 /**
 193  * of_usb_update_otg_caps - to update usb otg capabilities according to
 194  * the passed properties in DT.
 195  * @np: Pointer to the given device_node
 196  * @otg_caps: Pointer to the target usb_otg_caps to be set
 197  *
 198  * The function updates the otg capabilities
 199  */
 200 int of_usb_update_otg_caps(struct device_node *np,
 201                         struct usb_otg_caps *otg_caps)
 202 {
 203         u32 otg_rev;
 204
 205         if (!otg_caps)
 206                 return -EINVAL;
 207
 208         if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
 209                 switch (otg_rev) {
 210                 case 0x0100:
 211                 case 0x0120:
 212                 case 0x0130:
 213                 case 0x0200:
 214                         /* Choose the lesser one if it's already been set */
 215                         if (otg_caps->otg_rev)
 216                                 otg_caps->otg_rev = min_t(u16, otg_rev,
 217                                                         otg_caps->otg_rev);
 218                         else
 219                                 otg_caps->otg_rev = otg_rev;
 220                         break;
 221                 default:
 222                         pr_err("%s: unsupported otg-rev: 0x%x\n",
 223                                                 np->full_name, otg_rev);
 224                         return -EINVAL;
 225                 }
 226         } else {
 227                 /*
 228                  * otg-rev is mandatory for otg properties, if not passed
 229                  * we set it to be 0 and assume it's a legacy otg device.
 230                  * Non-dt platform can set it afterwards.
 231                  */
 232                 otg_caps->otg_rev = 0;
 233         }
 234
 235         if (of_find_property(np, "hnp-disable", NULL))
 236                 otg_caps->hnp_support = false;
 237         if (of_find_property(np, "srp-disable", NULL))
 238                 otg_caps->srp_support = false;
 239         if (of_find_property(np, "adp-disable", NULL) ||
 240                                 (otg_caps->otg_rev < 0x0200))
 241                 otg_caps->adp_support = false;
 242
 243         return 0;
 244 }
 245 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
 246
 247 #endif
 248
 249 MODULE_LICENSE("GPL");