xref: /openbmc/u-boot/arch/arm/cpu/armv7/syslib.c (revision d66ff4ba)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2008
4  * Texas Instruments, <www.ti.com>
5  *
6  * Richard Woodruff <r-woodruff2@ti.com>
7  * Syed Mohammed Khasim <khasim@ti.com>
8  */
9 
10 #include <common.h>
11 #include <asm/io.h>
12 
13 /************************************************************
14  * sdelay() - simple spin loop.  Will be constant time as
15  *  its generally used in bypass conditions only.  This
16  *  is necessary until timers are accessible.
17  *
18  *  not inline to increase chances its in cache when called
19  *************************************************************/
20 void sdelay(unsigned long loops)
21 {
22 	__asm__ volatile ("1:\n" "subs %0, %1, #1\n"
23 			  "bne 1b":"=r" (loops):"0"(loops));
24 }
25 
26 /*********************************************************************
27  * wait_on_value() - common routine to allow waiting for changes in
28  *   volatile regs.
29  *********************************************************************/
30 u32 wait_on_value(u32 read_bit_mask, u32 match_value, void *read_addr,
31 		  u32 bound)
32 {
33 	u32 i = 0, val;
34 	do {
35 		++i;
36 		val = readl((u32)read_addr) & read_bit_mask;
37 		if (val == match_value)
38 			return 1;
39 		if (i == bound)
40 			return 0;
41 	} while (1);
42 }
43