97 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * reset.c - logic for resetting the cpu
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|  *
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|  * Copyright (c) 2005-2008 Analog Devices Inc.
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|  *
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|  * Licensed under the GPL-2 or later.
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|  */
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| 
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| #include <common.h>
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| #include <command.h>
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| #include <asm/blackfin.h>
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| #include <asm/mach-common/bits/bootrom.h>
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| #include "cpu.h"
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| 
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| /* A system soft reset makes external memory unusable so force
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|  * this function into L1.  We use the compiler ssync here rather
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|  * than SSYNC() because it's safe (no interrupts and such) and
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|  * we save some L1.  We do not need to force sanity in the SYSCR
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|  * register as the BMODE selection bit is cleared by the soft
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|  * reset while the Core B bit (on dual core parts) is cleared by
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|  * the core reset.
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|  */
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| __attribute__ ((__l1_text__, __noreturn__))
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| static void bfin_reset(void)
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| {
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| #ifdef SWRST
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| 	/* Wait for completion of "system" events such as cache line
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| 	 * line fills so that we avoid infinite stalls later on as
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| 	 * much as possible.  This code is in L1, so it won't trigger
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| 	 * any such event after this point in time.
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| 	 */
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| 	__builtin_bfin_ssync();
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| 
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| 	/* Initiate System software reset. */
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| 	bfin_write_SWRST(0x7);
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| 
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| 	/* Due to the way reset is handled in the hardware, we need
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| 	 * to delay for 10 SCLKS.  The only reliable way to do this is
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| 	 * to calculate the CCLK/SCLK ratio and multiply 10.  For now,
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| 	 * we'll assume worse case which is a 1:15 ratio.
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| 	 */
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| 	asm(
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| 		"LSETUP (1f, 1f) LC0 = %0\n"
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| 		"1: nop;"
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| 		:
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| 		: "a" (15 * 10)
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| 		: "LC0", "LB0", "LT0"
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| 	);
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| 
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| 	/* Clear System software reset */
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| 	bfin_write_SWRST(0);
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| 
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| 	/* The BF526 ROM will crash during reset */
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| #if defined(__ADSPBF522__) || defined(__ADSPBF524__) || defined(__ADSPBF526__)
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| 	/* Seems to be fixed with newer parts though ... */
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| 	if (__SILICON_REVISION__ < 1 && bfin_revid() < 1)
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| 		bfin_read_SWRST();
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| #endif
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| 
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| 	/* Wait for the SWRST write to complete.  Cannot rely on SSYNC
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| 	 * though as the System state is all reset now.
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| 	 */
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| 	asm(
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| 		"LSETUP (1f, 1f) LC1 = %0\n"
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| 		"1: nop;"
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| 		:
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| 		: "a" (15 * 1)
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| 		: "LC1", "LB1", "LT1"
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| 	);
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| #endif
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| 
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| 	while (1)
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| #if defined(__ADSPBF60x__)
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| 		bfin_write_RCU0_CTL(0x1);
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| #else
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| 		/* Issue core reset */
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| 		asm("raise 1");
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| #endif
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| }
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| 
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| /* We need to trampoline ourselves up into L1 since our linker
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|  * does not have relaxtion support and will only generate a
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|  * PC relative call with a 25 bit immediate.  This is not enough
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|  * to get us from the top of SDRAM into L1.
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|  */
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| int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
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| {
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| 	if (board_reset)
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| 		board_reset();
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| 	if (ANOMALY_05000353 || ANOMALY_05000386)
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| 		while (1)
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| 			asm("jump (%0);" : : "a" (bfin_reset));
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| 	else
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| 		bfrom_SoftReset((void *)(L1_SRAM_SCRATCH_END - 20));
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| 	return 0;
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| }
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