1 /* $NetBSD: nouveau_nvkm_subdev_i2c_pad.c,v 1.5 2021/12/18 23:45:40 riastradh Exp $ */
2
3 /*
4 * Copyright 2015 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 <bskeggs@redhat.com>
25 */
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_i2c_pad.c,v 1.5 2021/12/18 23:45:40 riastradh Exp $");
28
29 #include "pad.h"
30
31 #include <linux/nbsd-namespace.h>
32
33 static void
nvkm_i2c_pad_mode_locked(struct nvkm_i2c_pad * pad,enum nvkm_i2c_pad_mode mode)34 nvkm_i2c_pad_mode_locked(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
35 {
36 PAD_TRACE(pad, "-> %s", (mode == NVKM_I2C_PAD_AUX) ? "aux" :
37 (mode == NVKM_I2C_PAD_I2C) ? "i2c" : "off");
38 if (pad->func->mode)
39 pad->func->mode(pad, mode);
40 }
41
42 void
nvkm_i2c_pad_mode(struct nvkm_i2c_pad * pad,enum nvkm_i2c_pad_mode mode)43 nvkm_i2c_pad_mode(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
44 {
45 PAD_TRACE(pad, "mode %d", mode);
46 mutex_lock(&pad->mutex);
47 nvkm_i2c_pad_mode_locked(pad, mode);
48 pad->mode = mode;
49 mutex_unlock(&pad->mutex);
50 }
51
52 void
nvkm_i2c_pad_release(struct nvkm_i2c_pad * pad)53 nvkm_i2c_pad_release(struct nvkm_i2c_pad *pad)
54 {
55 PAD_TRACE(pad, "release");
56 if (pad->mode == NVKM_I2C_PAD_OFF)
57 nvkm_i2c_pad_mode_locked(pad, pad->mode);
58 mutex_unlock(&pad->mutex);
59 }
60
61 int
nvkm_i2c_pad_acquire(struct nvkm_i2c_pad * pad,enum nvkm_i2c_pad_mode mode)62 nvkm_i2c_pad_acquire(struct nvkm_i2c_pad *pad, enum nvkm_i2c_pad_mode mode)
63 {
64 PAD_TRACE(pad, "acquire");
65 mutex_lock(&pad->mutex);
66 if (pad->mode != mode) {
67 if (pad->mode != NVKM_I2C_PAD_OFF) {
68 mutex_unlock(&pad->mutex);
69 return -EBUSY;
70 }
71 nvkm_i2c_pad_mode_locked(pad, mode);
72 }
73 return 0;
74 }
75
76 void
nvkm_i2c_pad_fini(struct nvkm_i2c_pad * pad)77 nvkm_i2c_pad_fini(struct nvkm_i2c_pad *pad)
78 {
79 PAD_TRACE(pad, "fini");
80 nvkm_i2c_pad_mode_locked(pad, NVKM_I2C_PAD_OFF);
81 }
82
83 void
nvkm_i2c_pad_init(struct nvkm_i2c_pad * pad)84 nvkm_i2c_pad_init(struct nvkm_i2c_pad *pad)
85 {
86 PAD_TRACE(pad, "init");
87 nvkm_i2c_pad_mode_locked(pad, pad->mode);
88 }
89
90 void
nvkm_i2c_pad_del(struct nvkm_i2c_pad ** ppad)91 nvkm_i2c_pad_del(struct nvkm_i2c_pad **ppad)
92 {
93 struct nvkm_i2c_pad *pad = *ppad;
94 if (pad) {
95 PAD_TRACE(pad, "dtor");
96 list_del(&pad->head);
97 mutex_destroy(&pad->mutex);
98 kfree(pad);
99 pad = NULL;
100 }
101 }
102
103 void
nvkm_i2c_pad_ctor(const struct nvkm_i2c_pad_func * func,struct nvkm_i2c * i2c,int id,struct nvkm_i2c_pad * pad)104 nvkm_i2c_pad_ctor(const struct nvkm_i2c_pad_func *func, struct nvkm_i2c *i2c,
105 int id, struct nvkm_i2c_pad *pad)
106 {
107 pad->func = func;
108 pad->i2c = i2c;
109 pad->id = id;
110 pad->mode = NVKM_I2C_PAD_OFF;
111 mutex_init(&pad->mutex);
112 list_add_tail(&pad->head, &i2c->pad);
113 PAD_TRACE(pad, "ctor");
114 }
115
116 int
nvkm_i2c_pad_new_(const struct nvkm_i2c_pad_func * func,struct nvkm_i2c * i2c,int id,struct nvkm_i2c_pad ** ppad)117 nvkm_i2c_pad_new_(const struct nvkm_i2c_pad_func *func, struct nvkm_i2c *i2c,
118 int id, struct nvkm_i2c_pad **ppad)
119 {
120 if (!(*ppad = kzalloc(sizeof(**ppad), GFP_KERNEL)))
121 return -ENOMEM;
122 nvkm_i2c_pad_ctor(func, i2c, id, *ppad);
123 return 0;
124 }
125