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
33static void
34nvkm_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
42void
43nvkm_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
52void
53nvkm_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
61int
62nvkm_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
76void
77nvkm_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
83void
84nvkm_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
90void
91nvkm_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
103void
104nvkm_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
116int
117nvkm_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