kernel/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
  21 const char *usb_otg_state_string(enum usb_otg_state state)
  22 {
  23         static const char *const names[] = {
  24                 [OTG_STATE_A_IDLE] = "a_idle",
  25                 [OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
  26                 [OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
  27                 [OTG_STATE_A_HOST] = "a_host",
  28                 [OTG_STATE_A_SUSPEND] = "a_suspend",
  29                 [OTG_STATE_A_PERIPHERAL] = "a_peripheral",
  30                 [OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
  31                 [OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
  32                 [OTG_STATE_B_IDLE] = "b_idle",
  33                 [OTG_STATE_B_SRP_INIT] = "b_srp_init",
  34                 [OTG_STATE_B_PERIPHERAL] = "b_peripheral",
  35                 [OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
  36                 [OTG_STATE_B_HOST] = "b_host",
  37         };
  38
  39         if (state < 0 || state >= ARRAY_SIZE(names))
  40                 return "UNDEFINED";
  41
  42         return names[state];
  43 }
  44 EXPORT_SYMBOL_GPL(usb_otg_state_string);
  45
  46 static const char *const speed_names[] = {
  47         [USB_SPEED_UNKNOWN] = "UNKNOWN",
  48         [USB_SPEED_LOW] = "low-speed",
  49         [USB_SPEED_FULL] = "full-speed",
  50         [USB_SPEED_HIGH] = "high-speed",
  51         [USB_SPEED_WIRELESS] = "wireless",
  52         [USB_SPEED_SUPER] = "super-speed",
  53         [USB_SPEED_SUPER_PLUS] = "super-speed-plus",
  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 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
 111 {
 112         const char *dr_mode;
 113         int err, i;
 114
 115         err = device_property_read_string(dev, "dr_mode", &dr_mode);
 116         if (err < 0)
 117                 return USB_DR_MODE_UNKNOWN;
 118
 119         for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
 120                 if (!strcmp(dr_mode, usb_dr_modes[i]))
 121                         return i;
 122
 123         return USB_DR_MODE_UNKNOWN;
 124 }
 125 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
 126
 127 #ifdef CONFIG_OF
 128 /**
 129  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
 130  * for given targeted hosts (non-PC hosts)
 131  * @np: Pointer to the given device_node
 132  *
 133  * The function gets if the targeted hosts support TPL or not
 134  */
 135 bool of_usb_host_tpl_support(struct device_node *np)
 136 {
 137         if (of_find_property(np, "tpl-support", NULL))
 138                 return true;
 139
 140         return false;
 141 }
 142 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
 143
 144 /**
 145  * of_usb_update_otg_caps - to update usb otg capabilities according to
 146  * the passed properties in DT.
 147  * @np: Pointer to the given device_node
 148  * @otg_caps: Pointer to the target usb_otg_caps to be set
 149  *
 150  * The function updates the otg capabilities
 151  */
 152 int of_usb_update_otg_caps(struct device_node *np,
 153                         struct usb_otg_caps *otg_caps)
 154 {
 155         u32 otg_rev;
 156
 157         if (!otg_caps)
 158                 return -EINVAL;
 159
 160         if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
 161                 switch (otg_rev) {
 162                 case 0x0100:
 163                 case 0x0120:
 164                 case 0x0130:
 165                 case 0x0200:
 166                         /* Choose the lesser one if it's already been set */
 167                         if (otg_caps->otg_rev)
 168                                 otg_caps->otg_rev = min_t(u16, otg_rev,
 169                                                         otg_caps->otg_rev);
 170                         else
 171                                 otg_caps->otg_rev = otg_rev;
 172                         break;
 173                 default:
 174                         pr_err("%s: unsupported otg-rev: 0x%x\n",
 175                                                 np->full_name, otg_rev);
 176                         return -EINVAL;
 177                 }
 178         } else {
 179                 /*
 180                  * otg-rev is mandatory for otg properties, if not passed
 181                  * we set it to be 0 and assume it's a legacy otg device.
 182                  * Non-dt platform can set it afterwards.
 183                  */
 184                 otg_caps->otg_rev = 0;
 185         }
 186
 187         if (of_find_property(np, "hnp-disable", NULL))
 188                 otg_caps->hnp_support = false;
 189         if (of_find_property(np, "srp-disable", NULL))
 190                 otg_caps->srp_support = false;
 191         if (of_find_property(np, "adp-disable", NULL) ||
 192                                 (otg_caps->otg_rev < 0x0200))
 193                 otg_caps->adp_support = false;
 194
 195         return 0;
 196 }
 197 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
 198
 199 #endif
 200
 201 MODULE_LICENSE("GPL");