1 /* $NetBSD: nouveau_nvkm_subdev_volt_gpio.c,v 1.4 2021/12/18 23:45:42 riastradh Exp $ */
2
3 /*
4 * Copyright 2013 Red Hat Inc.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors: Ben Skeggs
25 */
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_volt_gpio.c,v 1.4 2021/12/18 23:45:42 riastradh Exp $");
28
29 #include <subdev/volt.h>
30 #include <subdev/bios.h>
31 #include <subdev/bios/gpio.h>
32 #include <subdev/gpio.h>
33 #include "priv.h"
34
35 #include "priv.h"
36
37 static const u8 tags[] = {
38 DCB_GPIO_VID0, DCB_GPIO_VID1, DCB_GPIO_VID2, DCB_GPIO_VID3,
39 DCB_GPIO_VID4, DCB_GPIO_VID5, DCB_GPIO_VID6, DCB_GPIO_VID7,
40 };
41
42 int
nvkm_voltgpio_get(struct nvkm_volt * volt)43 nvkm_voltgpio_get(struct nvkm_volt *volt)
44 {
45 struct nvkm_gpio *gpio = volt->subdev.device->gpio;
46 u8 vid = 0;
47 int i;
48
49 for (i = 0; i < ARRAY_SIZE(tags); i++) {
50 if (volt->vid_mask & (1 << i)) {
51 int ret = nvkm_gpio_get(gpio, 0, tags[i], 0xff);
52 if (ret < 0)
53 return ret;
54 vid |= ret << i;
55 }
56 }
57
58 return vid;
59 }
60
61 int
nvkm_voltgpio_set(struct nvkm_volt * volt,u8 vid)62 nvkm_voltgpio_set(struct nvkm_volt *volt, u8 vid)
63 {
64 struct nvkm_gpio *gpio = volt->subdev.device->gpio;
65 int i;
66
67 for (i = 0; i < ARRAY_SIZE(tags); i++, vid >>= 1) {
68 if (volt->vid_mask & (1 << i)) {
69 int ret = nvkm_gpio_set(gpio, 0, tags[i], 0xff, vid & 1);
70 if (ret < 0)
71 return ret;
72 }
73 }
74
75 return 0;
76 }
77
78 int
nvkm_voltgpio_init(struct nvkm_volt * volt)79 nvkm_voltgpio_init(struct nvkm_volt *volt)
80 {
81 struct nvkm_subdev *subdev = &volt->subdev;
82 struct nvkm_gpio *gpio = subdev->device->gpio;
83 struct dcb_gpio_func func;
84 int i;
85
86 /* check we have gpio function info for each vid bit. on some
87 * boards (ie. nvs295) the vid mask has more bits than there
88 * are valid gpio functions... from traces, nvidia appear to
89 * just touch the existing ones, so let's mask off the invalid
90 * bits and continue with life
91 */
92 for (i = 0; i < ARRAY_SIZE(tags); i++) {
93 if (volt->vid_mask & (1 << i)) {
94 int ret = nvkm_gpio_find(gpio, 0, tags[i], 0xff, &func);
95 if (ret) {
96 if (ret != -ENOENT)
97 return ret;
98 nvkm_debug(subdev, "VID bit %d has no GPIO\n", i);
99 volt->vid_mask &= ~(1 << i);
100 }
101 }
102 }
103
104 return 0;
105 }
106