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 };
  55
  56 const char *usb_speed_string(enum usb_device_speed speed)
  57 {
  58         if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
  59                 speed = USB_SPEED_UNKNOWN;
  60         return speed_names[speed];
  61 }
  62 EXPORT_SYMBOL_GPL(usb_speed_string);
  63
  64 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
  65 {
  66         const char *maximum_speed;
  67         int err;
  68         int i;
  69
  70         err = device_property_read_string(dev, "maximum-speed", &maximum_speed);
  71         if (err < 0)
  72                 return USB_SPEED_UNKNOWN;
  73
  74         for (i = 0; i < ARRAY_SIZE(speed_names); i++)
  75                 if (strcmp(maximum_speed, speed_names[i]) == 0)
  76                         return i;
  77
  78         return USB_SPEED_UNKNOWN;
  79 }
  80 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
  81
  82 const char *usb_state_string(enum usb_device_state state)
  83 {
  84         static const char *const names[] = {
  85                 [USB_STATE_NOTATTACHED] = "not attached",
  86                 [USB_STATE_ATTACHED] = "attached",
  87                 [USB_STATE_POWERED] = "powered",
  88                 [USB_STATE_RECONNECTING] = "reconnecting",
  89                 [USB_STATE_UNAUTHENTICATED] = "unauthenticated",
  90                 [USB_STATE_DEFAULT] = "default",
  91                 [USB_STATE_ADDRESS] = "addressed",
  92                 [USB_STATE_CONFIGURED] = "configured",
  93                 [USB_STATE_SUSPENDED] = "suspended",
  94         };
  95
  96         if (state < 0 || state >= ARRAY_SIZE(names))
  97                 return "UNKNOWN";
  98
  99         return names[state];
 100 }
 101 EXPORT_SYMBOL_GPL(usb_state_string);
 102
 103 static const char *const usb_dr_modes[] = {
 104         [USB_DR_MODE_UNKNOWN]           = "",
 105         [USB_DR_MODE_HOST]              = "host",
 106         [USB_DR_MODE_PERIPHERAL]        = "peripheral",
 107         [USB_DR_MODE_OTG]               = "otg",
 108 };
 109
 110 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
 111 {
 112         int i;
 113
 114         for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
 115                 if (!strcmp(usb_dr_modes[i], str))
 116                         return i;
 117
 118         return USB_DR_MODE_UNKNOWN;
 119 }
 120
 121 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
 122 {
 123         const char *dr_mode;
 124         int err;
 125
 126         err = device_property_read_string(dev, "dr_mode", &dr_mode);
 127         if (err < 0)
 128                 return USB_DR_MODE_UNKNOWN;
 129
 130         return usb_get_dr_mode_from_string(dr_mode);
 131 }
 132 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
 133
 134 #ifdef CONFIG_OF
 135 /**
 136  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
 137  * which is associated with the given phy device_node
 138  * @np: Pointer to the given phy device_node
 139  *
 140  * In dts a usb controller associates with phy devices.  The function gets
 141  * the string from property 'dr_mode' of the controller associated with the
 142  * given phy device node, and returns the correspondig enum usb_dr_mode.
 143  */
 144 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
 145 {
 146         struct device_node *controller = NULL;
 147         struct device_node *phy;
 148         const char *dr_mode;
 149         int index;
 150         int err;
 151
 152         do {
 153                 controller = of_find_node_with_property(controller, "phys");
 154                 index = 0;
 155                 do {
 156                         phy = of_parse_phandle(controller, "phys", index);
 157                         of_node_put(phy);
 158                         if (phy == phy_np)
 159                                 goto finish;
 160                         index++;
 161                 } while (phy);
 162         } while (controller);
 163
 164 finish:
 165         err = of_property_read_string(controller, "dr_mode", &dr_mode);
 166         of_node_put(controller);
 167
 168         if (err < 0)
 169                 return USB_DR_MODE_UNKNOWN;
 170
 171         return usb_get_dr_mode_from_string(dr_mode);
 172 }
 173 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
 174
 175 /**
 176  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 177  * for given targeted hosts (non-PC hosts)
 178  * @np: Pointer to the given device_node
 179  *
 180  * The function gets if the targeted hosts support TPL or not
 181  */
 182 bool of_usb_host_tpl_support(struct device_node *np)
 183 {
 184         if (of_find_property(np, "tpl-support", NULL))
 185                 return true;
 186
 187         return false;
 188 }
 189 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
 190
 191 /**
 192  * of_usb_update_otg_caps - to update usb otg capabilities according to
 193  * the passed properties in DT.
 194  * @np: Pointer to the given device_node
 195  * @otg_caps: Pointer to the target usb_otg_caps to be set
 196  *
 197  * The function updates the otg capabilities
 198  */
 199 int of_usb_update_otg_caps(struct device_node *np,
 200                         struct usb_otg_caps *otg_caps)
 201 {
 202         u32 otg_rev;
 203
 204         if (!otg_caps)
 205                 return -EINVAL;
 206
 207         if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
 208                 switch (otg_rev) {
 209                 case 0x0100:
 210                 case 0x0120:
 211                 case 0x0130:
 212                 case 0x0200:
 213                         /* Choose the lesser one if it's already been set */
 214                         if (otg_caps->otg_rev)
 215                                 otg_caps->otg_rev = min_t(u16, otg_rev,
 216                                                         otg_caps->otg_rev);
 217                         else
 218                                 otg_caps->otg_rev = otg_rev;
 219                         break;
 220                 default:
 221                         pr_err("%s: unsupported otg-rev: 0x%x\n",
 222                                                 np->full_name, otg_rev);
 223                         return -EINVAL;
 224                 }
 225         } else {
 226                 /*
 227                  * otg-rev is mandatory for otg properties, if not passed
 228                  * we set it to be 0 and assume it's a legacy otg device.
 229                  * Non-dt platform can set it afterwards.
 230                  */
 231                 otg_caps->otg_rev = 0;
 232         }
 233
 234         if (of_find_property(np, "hnp-disable", NULL))
 235                 otg_caps->hnp_support = false;
 236         if (of_find_property(np, "srp-disable", NULL))
 237                 otg_caps->srp_support = false;
 238         if (of_find_property(np, "adp-disable", NULL) ||
 239                                 (otg_caps->otg_rev < 0x0200))
 240                 otg_caps->adp_support = false;
 241
 242         return 0;
 243 }
 244 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
 245
 246 #endif
 247
 248 MODULE_LICENSE("GPL");