1 /*
2  * Copyright 2013 Red Hat Inc.
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: Ben Skeggs
23  */
24 #include <subdev/volt.h>
25 #include <subdev/bios.h>
26 #include <subdev/bios/vmap.h>
27 #include <subdev/bios/volt.h>
28 
29 static int
30 nvkm_volt_get(struct nvkm_volt *volt)
31 {
32 	if (volt->vid_get) {
33 		int ret = volt->vid_get(volt), i;
34 		if (ret >= 0) {
35 			for (i = 0; i < volt->vid_nr; i++) {
36 				if (volt->vid[i].vid == ret)
37 					return volt->vid[i].uv;
38 			}
39 			ret = -EINVAL;
40 		}
41 		return ret;
42 	}
43 	return -ENODEV;
44 }
45 
46 static int
47 nvkm_volt_set(struct nvkm_volt *volt, u32 uv)
48 {
49 	struct nvkm_subdev *subdev = &volt->subdev;
50 	if (volt->vid_set) {
51 		int i, ret = -EINVAL;
52 		for (i = 0; i < volt->vid_nr; i++) {
53 			if (volt->vid[i].uv == uv) {
54 				ret = volt->vid_set(volt, volt->vid[i].vid);
55 				nvkm_debug(subdev, "set %duv: %d\n", uv, ret);
56 				break;
57 			}
58 		}
59 		return ret;
60 	}
61 	return -ENODEV;
62 }
63 
64 static int
65 nvkm_volt_map(struct nvkm_volt *volt, u8 id)
66 {
67 	struct nvkm_bios *bios = nvkm_bios(volt);
68 	struct nvbios_vmap_entry info;
69 	u8  ver, len;
70 	u16 vmap;
71 
72 	vmap = nvbios_vmap_entry_parse(bios, id, &ver, &len, &info);
73 	if (vmap) {
74 		if (info.link != 0xff) {
75 			int ret = nvkm_volt_map(volt, info.link);
76 			if (ret < 0)
77 				return ret;
78 			info.min += ret;
79 		}
80 		return info.min;
81 	}
82 
83 	return id ? id * 10000 : -ENODEV;
84 }
85 
86 static int
87 nvkm_volt_set_id(struct nvkm_volt *volt, u8 id, int condition)
88 {
89 	int ret = nvkm_volt_map(volt, id);
90 	if (ret >= 0) {
91 		int prev = nvkm_volt_get(volt);
92 		if (!condition || prev < 0 ||
93 		    (condition < 0 && ret < prev) ||
94 		    (condition > 0 && ret > prev)) {
95 			ret = nvkm_volt_set(volt, ret);
96 		} else {
97 			ret = 0;
98 		}
99 	}
100 	return ret;
101 }
102 
103 static void
104 nvkm_volt_parse_bios(struct nvkm_bios *bios, struct nvkm_volt *volt)
105 {
106 	struct nvbios_volt_entry ivid;
107 	struct nvbios_volt info;
108 	u8  ver, hdr, cnt, len;
109 	u16 data;
110 	int i;
111 
112 	data = nvbios_volt_parse(bios, &ver, &hdr, &cnt, &len, &info);
113 	if (data && info.vidmask && info.base && info.step) {
114 		for (i = 0; i < info.vidmask + 1; i++) {
115 			if (info.base >= info.min &&
116 				info.base <= info.max) {
117 				volt->vid[volt->vid_nr].uv = info.base;
118 				volt->vid[volt->vid_nr].vid = i;
119 				volt->vid_nr++;
120 			}
121 			info.base += info.step;
122 		}
123 		volt->vid_mask = info.vidmask;
124 	} else if (data && info.vidmask) {
125 		for (i = 0; i < cnt; i++) {
126 			data = nvbios_volt_entry_parse(bios, i, &ver, &hdr,
127 						       &ivid);
128 			if (data) {
129 				volt->vid[volt->vid_nr].uv = ivid.voltage;
130 				volt->vid[volt->vid_nr].vid = ivid.vid;
131 				volt->vid_nr++;
132 			}
133 		}
134 		volt->vid_mask = info.vidmask;
135 	}
136 }
137 
138 int
139 _nvkm_volt_init(struct nvkm_object *object)
140 {
141 	struct nvkm_volt *volt = (void *)object;
142 	struct nvkm_subdev *subdev = &volt->subdev;
143 	int ret;
144 
145 	ret = nvkm_subdev_init(&volt->subdev);
146 	if (ret)
147 		return ret;
148 
149 	ret = volt->get(volt);
150 	if (ret < 0) {
151 		if (ret != -ENODEV)
152 			nvkm_debug(subdev, "current voltage unknown\n");
153 		return 0;
154 	}
155 
156 	nvkm_debug(subdev, "current voltage: %duv\n", ret);
157 	return 0;
158 }
159 
160 void
161 _nvkm_volt_dtor(struct nvkm_object *object)
162 {
163 	struct nvkm_volt *volt = (void *)object;
164 	nvkm_subdev_destroy(&volt->subdev);
165 }
166 
167 int
168 nvkm_volt_create_(struct nvkm_object *parent, struct nvkm_object *engine,
169 		  struct nvkm_oclass *oclass, int length, void **pobject)
170 {
171 	struct nvkm_device *device = (void *)parent;
172 	struct nvkm_bios *bios = device->bios;
173 	struct nvkm_volt *volt;
174 	int ret, i;
175 
176 	ret = nvkm_subdev_create_(parent, engine, oclass, 0, "VOLT",
177 				  "voltage", length, pobject);
178 	volt = *pobject;
179 	if (ret)
180 		return ret;
181 
182 	volt->get = nvkm_volt_get;
183 	volt->set = nvkm_volt_set;
184 	volt->set_id = nvkm_volt_set_id;
185 
186 	/* Assuming the non-bios device should build the voltage table later */
187 	if (bios)
188 		nvkm_volt_parse_bios(bios, volt);
189 
190 	if (volt->vid_nr) {
191 		for (i = 0; i < volt->vid_nr; i++) {
192 			nvkm_debug(&volt->subdev, "VID %02x: %duv\n",
193 				   volt->vid[i].vid, volt->vid[i].uv);
194 		}
195 
196 		/*XXX: this is an assumption.. there probably exists boards
197 		 * out there with i2c-connected voltage controllers too..
198 		 */
199 		ret = nvkm_voltgpio_init(volt);
200 		if (ret == 0) {
201 			volt->vid_get = nvkm_voltgpio_get;
202 			volt->vid_set = nvkm_voltgpio_set;
203 		}
204 	}
205 
206 	return ret;
207 }
208