src/jtag/drivers/jtag_usb_common.c

   1 /*
   2  * SPDX-License-Identifier: GPL-2.0+
   3  * Copyright (c) 2018 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
   4  */
   5
   6 #include <helper/log.h>
   7
   8 #include "jtag_usb_common.h"
   9
  10 static char *jtag_usb_location;
  11 /*
  12  * 1 char: bus
  13  * 2 * 7 chars: max 7 ports
  14  * 1 char: test for overflow
  15  * ------
  16  * 16 chars
  17  */
  18 #define JTAG_USB_MAX_LOCATION_LENGHT    16
  19
  20 void jtag_usb_set_location(const char *location)
  21 {
  22         if (strnlen(location, JTAG_USB_MAX_LOCATION_LENGHT) ==
  23             JTAG_USB_MAX_LOCATION_LENGHT)
  24                 LOG_WARNING("usb location string is too long!!\n");
  25
  26         if (jtag_usb_location)
  27                 free(jtag_usb_location);
  28
  29         jtag_usb_location = strndup(location, JTAG_USB_MAX_LOCATION_LENGHT);
  30 }
  31
  32 const char *jtag_usb_get_location(void)
  33 {
  34         return jtag_usb_location;
  35 }
  36
  37 bool jtag_usb_location_equal(uint8_t dev_bus, uint8_t *port_path,
  38                              size_t path_len)
  39 {
  40         size_t path_step, string_lengh;
  41         char *ptr, *loc;
  42         bool equal = false;
  43
  44         /* strtok need non const char */
  45         loc = strndup(jtag_usb_get_location(), JTAG_USB_MAX_LOCATION_LENGHT);
  46         string_lengh = strnlen(loc, JTAG_USB_MAX_LOCATION_LENGHT);
  47
  48         ptr = strtok(loc, "-");
  49         if (ptr == NULL) {
  50                 LOG_WARNING("no '-' in usb path\n");
  51                 goto done;
  52         }
  53
  54         string_lengh -= 1;
  55         /* check bus mismatch */
  56         if (atoi(ptr) != dev_bus)
  57                 goto done;
  58
  59         path_step = 0;
  60         while (path_step < path_len) {
  61                 ptr = strtok(NULL, ".");
  62
  63                 /* no more tokens in path */
  64                 if (ptr == NULL)
  65                         break;
  66
  67                 /* path mismatch at some step */
  68                 if (path_step < path_len && atoi(ptr) != port_path[path_step])
  69                         break;
  70
  71                 path_step++;
  72                 string_lengh -= 2;
  73         };
  74
  75         /* walked the full path, all elements match */
  76         if (path_step == path_len && !string_lengh)
  77                 equal = true;
  78
  79 done:
  80         free(loc);
  81         return equal;
  82 }