xref: /openbmc/u-boot/arch/arm/cpu/armv7/syslib.c (revision 83d290c56fab2d38cd1ab4c4cc7099559c1d5046)
1*83d290c5STom Rini // SPDX-License-Identifier: GPL-2.0+
287d98d3bSStefano Babic /*
387d98d3bSStefano Babic  * (C) Copyright 2008
487d98d3bSStefano Babic  * Texas Instruments, <www.ti.com>
587d98d3bSStefano Babic  *
687d98d3bSStefano Babic  * Richard Woodruff <r-woodruff2@ti.com>
787d98d3bSStefano Babic  * Syed Mohammed Khasim <khasim@ti.com>
887d98d3bSStefano Babic  */
987d98d3bSStefano Babic 
1087d98d3bSStefano Babic #include <common.h>
1187d98d3bSStefano Babic #include <asm/io.h>
1287d98d3bSStefano Babic 
1387d98d3bSStefano Babic /************************************************************
1487d98d3bSStefano Babic  * sdelay() - simple spin loop.  Will be constant time as
1587d98d3bSStefano Babic  *  its generally used in bypass conditions only.  This
1687d98d3bSStefano Babic  *  is necessary until timers are accessible.
1787d98d3bSStefano Babic  *
1887d98d3bSStefano Babic  *  not inline to increase chances its in cache when called
1987d98d3bSStefano Babic  *************************************************************/
sdelay(unsigned long loops)2087d98d3bSStefano Babic void sdelay(unsigned long loops)
2187d98d3bSStefano Babic {
2287d98d3bSStefano Babic 	__asm__ volatile ("1:\n" "subs %0, %1, #1\n"
2387d98d3bSStefano Babic 			  "bne 1b":"=r" (loops):"0"(loops));
2487d98d3bSStefano Babic }
2587d98d3bSStefano Babic 
2687d98d3bSStefano Babic /*********************************************************************
2787d98d3bSStefano Babic  * wait_on_value() - common routine to allow waiting for changes in
2887d98d3bSStefano Babic  *   volatile regs.
2987d98d3bSStefano Babic  *********************************************************************/
wait_on_value(u32 read_bit_mask,u32 match_value,void * read_addr,u32 bound)3087d98d3bSStefano Babic u32 wait_on_value(u32 read_bit_mask, u32 match_value, void *read_addr,
3187d98d3bSStefano Babic 		  u32 bound)
3287d98d3bSStefano Babic {
3387d98d3bSStefano Babic 	u32 i = 0, val;
3487d98d3bSStefano Babic 	do {
3587d98d3bSStefano Babic 		++i;
3687d98d3bSStefano Babic 		val = readl((u32)read_addr) & read_bit_mask;
3787d98d3bSStefano Babic 		if (val == match_value)
3887d98d3bSStefano Babic 			return 1;
3987d98d3bSStefano Babic 		if (i == bound)
4087d98d3bSStefano Babic 			return 0;
4187d98d3bSStefano Babic 	} while (1);
4287d98d3bSStefano Babic }
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