xref: /OK3568_Linux_fs/u-boot/arch/powerpc/cpu/mpc83xx/law.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright 2011 Freescale Semiconductor, Inc.
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <asm/fsl_law.h>
9*4882a593Smuzhiyun #include <asm/mmu.h>
10*4882a593Smuzhiyun #include <linux/log2.h>
11*4882a593Smuzhiyun 
set_ddr_laws(u64 start,u64 sz,enum law_trgt_if id)12*4882a593Smuzhiyun int set_ddr_laws(u64 start, u64 sz, enum law_trgt_if id)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun 	immap_t *immap = (immap_t *)CONFIG_SYS_IMMR;
15*4882a593Smuzhiyun 	law83xx_t *ecm = &immap->sysconf.ddrlaw[0];
16*4882a593Smuzhiyun 	u64 start_align, law_sz;
17*4882a593Smuzhiyun 	int law_sz_enc;
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun 	if (start == 0)
20*4882a593Smuzhiyun 		start_align = 1ull << (LAW_SIZE_2G + 1);
21*4882a593Smuzhiyun 	else
22*4882a593Smuzhiyun 		start_align = 1ull << (__ffs64(start));
23*4882a593Smuzhiyun 	law_sz = min(start_align, sz);
24*4882a593Smuzhiyun 	law_sz_enc = __ilog2_u64(law_sz) - 1;
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun 	/*
27*4882a593Smuzhiyun 	 * Set up LAWBAR for all of DDR.
28*4882a593Smuzhiyun 	 */
29*4882a593Smuzhiyun 	ecm->bar = start & 0xfffff000;
30*4882a593Smuzhiyun 	ecm->ar  = (LAWAR_EN | (id << 20) | (LAWAR_SIZE & law_sz_enc));
31*4882a593Smuzhiyun 	debug("DDR:bar=0x%08x\n", ecm->bar);
32*4882a593Smuzhiyun 	debug("DDR:ar=0x%08x\n", ecm->ar);
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun 	/* recalculate size based on what was actually covered by the law */
35*4882a593Smuzhiyun 	law_sz = 1ull << __ilog2_u64(law_sz);
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun 	/* do we still have anything to map */
38*4882a593Smuzhiyun 	sz = sz - law_sz;
39*4882a593Smuzhiyun 	if (sz) {
40*4882a593Smuzhiyun 		start += law_sz;
41*4882a593Smuzhiyun 
42*4882a593Smuzhiyun 		start_align = 1ull << (__ffs64(start));
43*4882a593Smuzhiyun 		law_sz = min(start_align, sz);
44*4882a593Smuzhiyun 		law_sz_enc = __ilog2_u64(law_sz) - 1;
45*4882a593Smuzhiyun 		ecm = &immap->sysconf.ddrlaw[1];
46*4882a593Smuzhiyun 		ecm->bar = start & 0xfffff000;
47*4882a593Smuzhiyun 		ecm->ar  = (LAWAR_EN | (id << 20) | (LAWAR_SIZE & law_sz_enc));
48*4882a593Smuzhiyun 		debug("DDR:bar=0x%08x\n", ecm->bar);
49*4882a593Smuzhiyun 		debug("DDR:ar=0x%08x\n", ecm->ar);
50*4882a593Smuzhiyun 	} else {
51*4882a593Smuzhiyun 		return 0;
52*4882a593Smuzhiyun 	}
53*4882a593Smuzhiyun 
54*4882a593Smuzhiyun 	/* do we still have anything to map */
55*4882a593Smuzhiyun 	sz = sz - law_sz;
56*4882a593Smuzhiyun 	if (sz)
57*4882a593Smuzhiyun 		return 1;
58*4882a593Smuzhiyun 
59*4882a593Smuzhiyun 	return 0;
60*4882a593Smuzhiyun }
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