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author | Peter Tyser <ptyser@xes-inc.com> | 2010-04-12 22:28:13 -0500 |
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committer | Wolfgang Denk <wd@denx.de> | 2010-04-13 09:13:25 +0200 |
commit | c6fb83d21729321426308c3acff2a3dfb20d250b (patch) | |
tree | 85b569582345fdd9361d8524df08e92251c84a59 /arch/blackfin/cpu/reset.c | |
parent | a4145534851bf74619cb373a942613a74547bb82 (diff) | |
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blackfin: Move cpu/blackfin/* to arch/blackfin/cpu/*
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Diffstat (limited to 'arch/blackfin/cpu/reset.c')
-rw-r--r-- | arch/blackfin/cpu/reset.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/arch/blackfin/cpu/reset.c b/arch/blackfin/cpu/reset.c new file mode 100644 index 0000000..e3be740 --- /dev/null +++ b/arch/blackfin/cpu/reset.c @@ -0,0 +1,106 @@ +/* + * reset.c - logic for resetting the cpu + * + * Copyright (c) 2005-2008 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + */ + +#include <common.h> +#include <command.h> +#include <asm/blackfin.h> +#include "cpu.h" + +/* A system soft reset makes external memory unusable so force + * this function into L1. We use the compiler ssync here rather + * than SSYNC() because it's safe (no interrupts and such) and + * we save some L1. We do not need to force sanity in the SYSCR + * register as the BMODE selection bit is cleared by the soft + * reset while the Core B bit (on dual core parts) is cleared by + * the core reset. + */ +__attribute__ ((__l1_text__, __noreturn__)) +static void bfin_reset(void) +{ + /* Wait for completion of "system" events such as cache line + * line fills so that we avoid infinite stalls later on as + * much as possible. This code is in L1, so it won't trigger + * any such event after this point in time. + */ + __builtin_bfin_ssync(); + + /* The bootrom checks to see how it was reset and will + * automatically perform a software reset for us when + * it starts executing after the core reset. + */ + if (ANOMALY_05000353 || ANOMALY_05000386) { + /* Initiate System software reset. */ + bfin_write_SWRST(0x7); + + /* Due to the way reset is handled in the hardware, we need + * to delay for 10 SCLKS. The only reliable way to do this is + * to calculate the CCLK/SCLK ratio and multiply 10. For now, + * we'll assume worse case which is a 1:15 ratio. + */ + asm( + "LSETUP (1f, 1f) LC0 = %0\n" + "1: nop;" + : + : "a" (15 * 10) + : "LC0", "LB0", "LT0" + ); + + /* Clear System software reset */ + bfin_write_SWRST(0); + + /* The BF526 ROM will crash during reset */ +#if defined(__ADSPBF522__) || defined(__ADSPBF524__) || defined(__ADSPBF526__) + bfin_read_SWRST(); +#endif + + /* Wait for the SWRST write to complete. Cannot rely on SSYNC + * though as the System state is all reset now. + */ + asm( + "LSETUP (1f, 1f) LC1 = %0\n" + "1: nop;" + : + : "a" (15 * 1) + : "LC1", "LB1", "LT1" + ); + } + + while (1) + /* Issue core reset */ + asm("raise 1"); +} + +/* We need to trampoline ourselves up into L1 since our linker + * does not have relaxtion support and will only generate a + * PC relative call with a 25 bit immediate. This is not enough + * to get us from the top of SDRAM into L1. + */ +__attribute__ ((__noreturn__)) +static inline void bfin_reset_trampoline(void) +{ + if (board_reset) + board_reset(); + while (1) + asm("jump (%0);" : : "a" (bfin_reset)); +} + +__attribute__ ((__noreturn__)) +void bfin_reset_or_hang(void) +{ +#ifdef CONFIG_PANIC_HANG + hang(); +#else + bfin_reset_trampoline(); +#endif +} + +int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +{ + bfin_reset_trampoline(); + return 0; +} |