xref: /linux/drivers/gpu/drm/nouveau/nvkm/subdev/fb/sddr2.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  * Copyright 2014 Roy Spliet
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Roy Spliet <rspliet@eclipso.eu>
23  *          Ben Skeggs
24  */
25 #include "priv.h"
26 
27 struct ramxlat {
28 	int id;
29 	u8 enc;
30 };
31 
32 static inline int
33 ramxlat(const struct ramxlat *xlat, int id)
34 {
35 	while (xlat->id >= 0) {
36 		if (xlat->id == id)
37 			return xlat->enc;
38 		xlat++;
39 	}
40 	return -EINVAL;
41 }
42 
43 static const struct ramxlat
44 ramddr2_cl[] = {
45 	{ 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 },
46 	/* The following are available in some, but not all DDR2 docs */
47 	{ 7, 7 },
48 	{ -1 }
49 };
50 
51 static const struct ramxlat
52 ramddr2_wr[] = {
53 	{ 2, 1 }, { 3, 2 }, { 4, 3 }, { 5, 4 }, { 6, 5 },
54 	/* The following are available in some, but not all DDR2 docs */
55 	{ 7, 6 },
56 	{ -1 }
57 };
58 
59 int
60 nvkm_sddr2_calc(struct nvkm_ram *ram)
61 {
62 	int CL, WR, DLL = 0, ODT = 0;
63 
64 	switch (ram->next->bios.timing_ver) {
65 	case 0x10:
66 		CL  = ram->next->bios.timing_10_CL;
67 		WR  = ram->next->bios.timing_10_WR;
68 		DLL = !ram->next->bios.ramcfg_10_DLLoff;
69 		ODT = ram->next->bios.timing_10_ODT & 3;
70 		break;
71 	case 0x20:
72 		CL  = (ram->next->bios.timing[1] & 0x0000001f);
73 		WR  = (ram->next->bios.timing[2] & 0x007f0000) >> 16;
74 		break;
75 	default:
76 		return -ENOSYS;
77 	}
78 
79 	CL  = ramxlat(ramddr2_cl, CL);
80 	WR  = ramxlat(ramddr2_wr, WR);
81 	if (CL < 0 || WR < 0)
82 		return -EINVAL;
83 
84 	ram->mr[0] &= ~0xf70;
85 	ram->mr[0] |= (WR & 0x07) << 9;
86 	ram->mr[0] |= (CL & 0x07) << 4;
87 
88 	ram->mr[1] &= ~0x045;
89 	ram->mr[1] |= (ODT & 0x1) << 2;
90 	ram->mr[1] |= (ODT & 0x2) << 5;
91 	ram->mr[1] |= !DLL;
92 	return 0;
93 }
94