xref: /openbmc/u-boot/arch/arm/mach-omap2/omap5/abb.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Adaptive Body Bias programming sequence for OMAP5 family
4  *
5  * (C) Copyright 2013
6  * Texas Instruments, <www.ti.com>
7  *
8  * Andrii Tseglytskyi <andrii.tseglytskyi@ti.com>
9  */
10 
11 #include <common.h>
12 #include <asm/omap_common.h>
13 #include <asm/io.h>
14 
15 /*
16  * Setup LDOVBB for OMAP5.
17  * On OMAP5+ some ABB settings are fused. They are handled
18  * in the following way:
19  *
20  * 1. corresponding EFUSE register contains ABB enable bit
21  *    and VSET value
22  * 2. If ABB enable bit is set to 1, than ABB should be
23  *    enabled, otherwise ABB should be disabled
24  * 3. If ABB is enabled, than VSET value should be copied
25  *    to corresponding MUX control register
26  */
27 s8 abb_setup_ldovbb(u32 fuse, u32 ldovbb)
28 {
29 	u32 vset;
30 	u32 fuse_enable_mask = OMAP5_PROD_ABB_FUSE_ENABLE_MASK;
31 	u32 fuse_vset_mask = OMAP5_PROD_ABB_FUSE_VSET_MASK;
32 
33 	if (!is_omap54xx()) {
34 		/* DRA7 */
35 		fuse_enable_mask = DRA7_ABB_FUSE_ENABLE_MASK;
36 		fuse_vset_mask = DRA7_ABB_FUSE_VSET_MASK;
37 	}
38 	/*
39 	 * ABB parameters must be properly fused
40 	 * otherwise ABB should be disabled
41 	 */
42 	vset = readl(fuse);
43 	if (!(vset & fuse_enable_mask))
44 		return -1;
45 
46 	/* prepare VSET value for LDOVBB mux register */
47 	vset &= fuse_vset_mask;
48 	vset >>= ffs(fuse_vset_mask) - 1;
49 	vset <<= ffs(OMAP5_ABB_LDOVBBMPU_VSET_OUT_MASK) - 1;
50 	vset |= OMAP5_ABB_LDOVBBMPU_MUX_CTRL_MASK;
51 
52 	/* setup LDOVBB using fused value */
53 	clrsetbits_le32(ldovbb,  OMAP5_ABB_LDOVBBMPU_VSET_OUT_MASK, vset);
54 
55 	return 0;
56 }
57