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