xref: /openbmc/u-boot/arch/powerpc/cpu/mpc83xx/law.c (revision c6af2e7d)
1 /*
2  * Copyright 2011 Freescale Semiconductor, Inc.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * Version 2 as published by the Free Software Foundation.
7  */
8 
9 #include <common.h>
10 #include <asm/fsl_law.h>
11 #include <asm/mmu.h>
12 
13 int set_ddr_laws(u64 start, u64 sz, enum law_trgt_if id)
14 {
15 	immap_t *immap = (immap_t *)CONFIG_SYS_IMMR;
16 	law83xx_t *ecm = &immap->sysconf.ddrlaw[0];
17 	u64 start_align, law_sz;
18 	int law_sz_enc;
19 
20 	if (start == 0)
21 		start_align = 1ull << (LAW_SIZE_2G + 1);
22 	else
23 		start_align = 1ull << (ffs64(start) - 1);
24 	law_sz = min(start_align, sz);
25 	law_sz_enc = __ilog2_u64(law_sz) - 1;
26 
27 	/*
28 	 * Set up LAWBAR for all of DDR.
29 	 */
30 	ecm->bar = start & 0xfffff000;
31 	ecm->ar  = (LAWAR_EN | (id << 20) | (LAWAR_SIZE & law_sz_enc));
32 	debug("DDR:bar=0x%08x\n", ecm->bar);
33 	debug("DDR:ar=0x%08x\n", ecm->ar);
34 
35 	/* recalculate size based on what was actually covered by the law */
36 	law_sz = 1ull << __ilog2_u64(law_sz);
37 
38 	/* do we still have anything to map */
39 	sz = sz - law_sz;
40 	if (sz) {
41 		start += law_sz;
42 
43 		start_align = 1ull << (ffs64(start) - 1);
44 		law_sz = min(start_align, sz);
45 		law_sz_enc = __ilog2_u64(law_sz) - 1;
46 		ecm = &immap->sysconf.ddrlaw[1];
47 		ecm->bar = start & 0xfffff000;
48 		ecm->ar  = (LAWAR_EN | (id << 20) | (LAWAR_SIZE & law_sz_enc));
49 		debug("DDR:bar=0x%08x\n", ecm->bar);
50 		debug("DDR:ar=0x%08x\n", ecm->ar);
51 	} else {
52 		return 0;
53 	}
54 
55 	/* do we still have anything to map */
56 	sz = sz - law_sz;
57 	if (sz)
58 		return 1;
59 
60 	return 0;
61 }
62