arch/arm/cpu/armv7/syslib.c

   1 /*
   2  * (C) Copyright 2008
   3  * Texas Instruments, <www.ti.com>
   4  *
   5  * Richard Woodruff <r-woodruff2@ti.com>
   6  * Syed Mohammed Khasim <khasim@ti.com>
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <common.h>
  12 #include <asm/io.h>
  13
  14 /************************************************************
  15  * sdelay() - simple spin loop.  Will be constant time as
  16  *  its generally used in bypass conditions only.  This
  17  *  is necessary until timers are accessible.
  18  *
  19  *  not inline to increase chances its in cache when called
  20  *************************************************************/
  21 void sdelay(unsigned long loops)
  22 {
  23         __asm__ volatile ("1:\n" "subs %0, %1, #1\n"
  24                           "bne 1b":"=r" (loops):"0"(loops));
  25 }
  26
  27 /*********************************************************************
  28  * wait_on_value() - common routine to allow waiting for changes in
  29  *   volatile regs.
  30  *********************************************************************/
  31 u32 wait_on_value(u32 read_bit_mask, u32 match_value, void *read_addr,
  32                   u32 bound)
  33 {
  34         u32 i = 0, val;
  35         do {
  36                 ++i;
  37                 val = readl((u32)read_addr) & read_bit_mask;
  38                 if (val == match_value)
  39                         return 1;
  40                 if (i == bound)
  41                         return 0;
  42         } while (1);
  43 }