xref: /linux/drivers/gpu/drm/nouveau/nvkm/subdev/fb/sddr2.c (revision 9095bf25ea08135a5b74875dd0e3eeaddc4218a0)
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 #include "ram.h"
27 
28 struct ramxlat {
29 	int id;
30 	u8 enc;
31 };
32 
33 static inline int
ramxlat(const struct ramxlat * xlat,int id)34 ramxlat(const struct ramxlat *xlat, int id)
35 {
36 	while (xlat->id >= 0) {
37 		if (xlat->id == id)
38 			return xlat->enc;
39 		xlat++;
40 	}
41 	return -EINVAL;
42 }
43 
44 static const struct ramxlat
45 ramddr2_cl[] = {
46 	{ 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 },
47 	/* The following are available in some, but not all DDR2 docs */
48 	{ 7, 7 },
49 	{ -1 }
50 };
51 
52 static const struct ramxlat
53 ramddr2_wr[] = {
54 	{ 2, 1 }, { 3, 2 }, { 4, 3 }, { 5, 4 }, { 6, 5 },
55 	/* The following are available in some, but not all DDR2 docs */
56 	{ 7, 6 },
57 	{ -1 }
58 };
59 
60 int
nvkm_sddr2_calc(struct nvkm_ram * ram)61 nvkm_sddr2_calc(struct nvkm_ram *ram)
62 {
63 	int CL, WR, DLL = 0, ODT = 0;
64 
65 	switch (ram->next->bios.timing_ver) {
66 	case 0x10:
67 		CL  = ram->next->bios.timing_10_CL;
68 		WR  = ram->next->bios.timing_10_WR;
69 		DLL = !ram->next->bios.ramcfg_DLLoff;
70 		ODT = ram->next->bios.timing_10_ODT & 3;
71 		break;
72 	case 0x20:
73 		CL  = (ram->next->bios.timing[1] & 0x0000001f);
74 		WR  = (ram->next->bios.timing[2] & 0x007f0000) >> 16;
75 		break;
76 	default:
77 		return -ENOSYS;
78 	}
79 
80 	if (ram->next->bios.timing_ver == 0x20 ||
81 	    ram->next->bios.ramcfg_timing == 0xff) {
82 		ODT =  (ram->mr[1] & 0x004) >> 2 |
83 		       (ram->mr[1] & 0x040) >> 5;
84 	}
85 
86 	CL  = ramxlat(ramddr2_cl, CL);
87 	WR  = ramxlat(ramddr2_wr, WR);
88 	if (CL < 0 || WR < 0)
89 		return -EINVAL;
90 
91 	ram->mr[0] &= ~0xf70;
92 	ram->mr[0] |= (WR & 0x07) << 9;
93 	ram->mr[0] |= (CL & 0x07) << 4;
94 
95 	ram->mr[1] &= ~0x045;
96 	ram->mr[1] |= (ODT & 0x1) << 2;
97 	ram->mr[1] |= (ODT & 0x2) << 5;
98 	ram->mr[1] |= !DLL;
99 	return 0;
100 }
101