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/gpio.h>
27 #include <subdev/gpio.h>
28 #include "priv.h"
29
30 static const u8 tags[] = {
31 DCB_GPIO_VID0, DCB_GPIO_VID1, DCB_GPIO_VID2, DCB_GPIO_VID3,
32 DCB_GPIO_VID4, DCB_GPIO_VID5, DCB_GPIO_VID6, DCB_GPIO_VID7,
33 };
34
35 int
nvkm_voltgpio_get(struct nvkm_volt * volt)36 nvkm_voltgpio_get(struct nvkm_volt *volt)
37 {
38 struct nvkm_gpio *gpio = volt->subdev.device->gpio;
39 u8 vid = 0;
40 int i;
41
42 for (i = 0; i < ARRAY_SIZE(tags); i++) {
43 if (volt->vid_mask & (1 << i)) {
44 int ret = nvkm_gpio_get(gpio, 0, tags[i], 0xff);
45 if (ret < 0)
46 return ret;
47 vid |= ret << i;
48 }
49 }
50
51 return vid;
52 }
53
54 int
nvkm_voltgpio_set(struct nvkm_volt * volt,u8 vid)55 nvkm_voltgpio_set(struct nvkm_volt *volt, u8 vid)
56 {
57 struct nvkm_gpio *gpio = volt->subdev.device->gpio;
58 int i;
59
60 for (i = 0; i < ARRAY_SIZE(tags); i++, vid >>= 1) {
61 if (volt->vid_mask & (1 << i)) {
62 int ret = nvkm_gpio_set(gpio, 0, tags[i], 0xff, vid & 1);
63 if (ret < 0)
64 return ret;
65 }
66 }
67
68 return 0;
69 }
70
71 int
nvkm_voltgpio_init(struct nvkm_volt * volt)72 nvkm_voltgpio_init(struct nvkm_volt *volt)
73 {
74 struct nvkm_subdev *subdev = &volt->subdev;
75 struct nvkm_gpio *gpio = subdev->device->gpio;
76 struct dcb_gpio_func func;
77 int i;
78
79 /* check we have gpio function info for each vid bit. on some
80 * boards (ie. nvs295) the vid mask has more bits than there
81 * are valid gpio functions... from traces, nvidia appear to
82 * just touch the existing ones, so let's mask off the invalid
83 * bits and continue with life
84 */
85 for (i = 0; i < ARRAY_SIZE(tags); i++) {
86 if (volt->vid_mask & (1 << i)) {
87 int ret = nvkm_gpio_find(gpio, 0, tags[i], 0xff, &func);
88 if (ret) {
89 if (ret != -ENOENT)
90 return ret;
91 nvkm_debug(subdev, "VID bit %d has no GPIO\n", i);
92 volt->vid_mask &= ~(1 << i);
93 }
94 }
95 }
96
97 return 0;
98 }
99