/* Get frequency of the system processor.  sparc64 version.

   Copyright (C) 2001-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <ctype.h>

#include <fcntl.h>

#include <string.h>

#include <unistd.h>

#include <dirent.h>

#include <stdlib.h>

#include <inttypes.h>

#include <sys/ioctl.h>

#include <asm/openpromio.h>

static hp_timing_t

__get_clockfreq_via_cpuinfo (void)

{

  hp_timing_t result;

  int fd;

  result = 0;

  fd = __open ("/proc/cpuinfo", O_RDONLY);

  if (fd != -1)

    {

      char buf[8192];

      ssize_t n;

      n = __read (fd, buf, sizeof buf);

      if (n > 0)

	{

	  char *mhz = memmem (buf, n, "Cpu0ClkTck", 7);

	  if (mhz != NULL)

	    {

	      char *endp = buf + n;

	      /* Search for the beginning of the string.  */

	      while (mhz < endp

		     && (*mhz < '0' || *mhz > '9')

		     && (*mhz < 'a' || *mhz > 'f')

		     && *mhz != '\n')

		++mhz;

	      while (mhz < endp && *mhz != '\n')

		{

		  if ((*mhz >= '0' && *mhz <= '9') ||

		      (*mhz >= 'a' && *mhz <= 'f'))

		    {

		      result <<= 4;

		      if (*mhz >= '0' && *mhz <= '9')

			result += *mhz - '0';

		      else

			result += (*mhz - 'a') + 10;

		    }

		  ++mhz;

		}

	    }

	}

      __close (fd);

    }

  return result;

}

static hp_timing_t

__get_clockfreq_via_proc_openprom (void)

{

  hp_timing_t result;

  int obp_fd;

  result = 0;

  obp_fd = __open ("/proc/openprom", O_RDONLY);

  if (obp_fd != -1)

    {

      unsigned long int buf[4096 / sizeof (unsigned long int)];

      struct dirent64 *dirp = (struct dirent64 *) buf;

      ssize_t len;

      while ((len = __getdents64 (obp_fd, (char *) dirp, sizeof (buf))) > 0)

	{

	  struct dirent64 *this_dirp = dirp;

	  while (len > 0)

	    {

	      char node[strlen ("/proc/openprom/")

			+ _D_ALLOC_NAMLEN (this_dirp)

			+ strlen ("/clock-frequency")];

	      char *prop;

	      int fd;

	      /* Note that

		   strlen("/clock-frequency") > strlen("/device_type")

	      */

	      __stpcpy (prop = __stpcpy (__stpcpy (node, "/proc/openprom/"),

					 this_dirp->d_name),

			"/device_type");

	      fd = __open (node, O_RDONLY);

	      if (fd != -1)

		{

		  char type_string[128];

		  int ret;

		  ret = __read (fd, type_string, sizeof (type_string));

		  if (ret > 0 && strncmp (type_string, "'cpu'", 5) == 0)

		    {

		      int clkfreq_fd;

		      __stpcpy (prop, "/clock-frequency");

		      clkfreq_fd = __open (node, O_RDONLY);

		      if (clkfreq_fd != -1)

			{

			  if (__read (clkfreq_fd, type_string,

				      sizeof (type_string)) > 0)

			    result = (hp_timing_t)

			      strtoumax (type_string, NULL, 16);

			  __close (clkfreq_fd);

			}

		    }

		  __close (fd);

		}

	      if (result != 0)

		break;

	      len -= this_dirp->d_reclen;

	      this_dirp = (struct dirent64 *)

		((char *) this_dirp + this_dirp->d_reclen);

	    }

	  if (result != 0)

	    break;

	}

      __close (obp_fd);

    }

  return result;

}

static void set_obp_int (struct openpromio *op, int val)

{

  char *cp = op->oprom_array;

  int *ip = (int *) cp;

  *ip = val;

}

static int get_obp_int (struct openpromio *op)

{

  char *cp = op->oprom_array;

  int *ip = (int *) cp;

  return *ip;

}

static hp_timing_t

__get_clockfreq_via_dev_openprom (void)

{

  hp_timing_t result;

  int obp_dev_fd;

  result = 0;

  obp_dev_fd = __open ("/dev/openprom", O_RDONLY);

  if (obp_dev_fd != -1)

    {

      char obp_buf[8192];

      struct openpromio *obp_cmd = (struct openpromio *)obp_buf;

      int ret;

      obp_cmd->oprom_size =

	sizeof (obp_buf) - sizeof (unsigned int);

      set_obp_int (obp_cmd, 0);

      ret = __ioctl (obp_dev_fd, OPROMCHILD, (char *) obp_cmd);

      if (ret == 0)

	{

	  int cur_node = get_obp_int (obp_cmd);

	  while (cur_node != 0 && cur_node != -1)

	    {

	      obp_cmd->oprom_size = sizeof (obp_buf) - sizeof (unsigned int);

	      strcpy (obp_cmd->oprom_array, "device_type");

	      ret = __ioctl (obp_dev_fd, OPROMGETPROP, (char *) obp_cmd);

	      if (ret == 0

		  && strncmp (obp_cmd->oprom_array, "cpu", 3) == 0)

		{

		  obp_cmd->oprom_size = (sizeof (obp_buf)

					 - sizeof (unsigned int));

		  strcpy (obp_cmd->oprom_array, "clock-frequency");

		  ret = __ioctl (obp_dev_fd, OPROMGETPROP, (char *) obp_cmd);

		  if (ret == 0)

		    result = (hp_timing_t) get_obp_int (obp_cmd);

		}

	      obp_cmd->oprom_size = sizeof (obp_buf) - sizeof (unsigned int);

	      set_obp_int (obp_cmd, cur_node);

	      ret = __ioctl (obp_dev_fd, OPROMNEXT, (char *) obp_cmd);

	      if (ret < 0)

		break;

	      cur_node = get_obp_int (obp_cmd);

	    }

	}

    }

  return result;

}

hp_timing_t

__get_clockfreq (void)

{

  static hp_timing_t result;

  /* If this function was called before, we know the result.  */

  if (result != 0)

    return result;

  /* We first read the information from the /proc/cpuinfo file.

     It contains at least one line like

	Cpu0ClkTick         : 000000002cb41780

     We search for this line and convert the number in an integer.  */

  result = __get_clockfreq_via_cpuinfo ();

  if (result != 0)

    return result;

  /* If that did not work, try to find an OpenPROM node

     with device_type equal to 'cpu' using /dev/openprom

     and fetch the clock-frequency property from there.  */

  result = __get_clockfreq_via_dev_openprom ();

  if (result != 0)

    return result;

  /* Finally, try the same lookup as above but using /proc/openprom.  */

  result = __get_clockfreq_via_proc_openprom ();

  return result;

}