1/*
2 * Copyright 2009 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
25#include <linux/string_helpers.h>
26
27#include "aux.h"
28#include "pad.h"
29
30static int
31nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
32{
33	struct nvkm_i2c_aux *aux = container_of(adap, typeof(*aux), i2c);
34	struct i2c_msg *msg = msgs;
35	int ret, mcnt = num;
36
37	ret = nvkm_i2c_aux_acquire(aux);
38	if (ret)
39		return ret;
40
41	while (mcnt--) {
42		u8 remaining = msg->len;
43		u8 *ptr = msg->buf;
44
45		while (remaining) {
46			u8 cnt, retries, cmd;
47
48			if (msg->flags & I2C_M_RD)
49				cmd = 1;
50			else
51				cmd = 0;
52
53			if (mcnt || remaining > 16)
54				cmd |= 4; /* MOT */
55
56			for (retries = 0, cnt = 0;
57			     retries < 32 && !cnt;
58			     retries++) {
59				cnt = min_t(u8, remaining, 16);
60				ret = aux->func->xfer(aux, true, cmd,
61						      msg->addr, ptr, &cnt);
62				if (ret < 0)
63					goto out;
64			}
65			if (!cnt) {
66				AUX_TRACE(aux, "no data after 32 retries");
67				ret = -EIO;
68				goto out;
69			}
70
71			ptr += cnt;
72			remaining -= cnt;
73		}
74
75		msg++;
76	}
77
78	ret = num;
79out:
80	nvkm_i2c_aux_release(aux);
81	return ret;
82}
83
84static u32
85nvkm_i2c_aux_i2c_func(struct i2c_adapter *adap)
86{
87	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
88}
89
90static const struct i2c_algorithm
91nvkm_i2c_aux_i2c_algo = {
92	.master_xfer = nvkm_i2c_aux_i2c_xfer,
93	.functionality = nvkm_i2c_aux_i2c_func
94};
95
96void
97nvkm_i2c_aux_monitor(struct nvkm_i2c_aux *aux, bool monitor)
98{
99	struct nvkm_i2c_pad *pad = aux->pad;
100	AUX_TRACE(aux, "monitor: %s", str_yes_no(monitor));
101	if (monitor)
102		nvkm_i2c_pad_mode(pad, NVKM_I2C_PAD_AUX);
103	else
104		nvkm_i2c_pad_mode(pad, NVKM_I2C_PAD_OFF);
105}
106
107void
108nvkm_i2c_aux_release(struct nvkm_i2c_aux *aux)
109{
110	struct nvkm_i2c_pad *pad = aux->pad;
111	AUX_TRACE(aux, "release");
112	nvkm_i2c_pad_release(pad);
113	mutex_unlock(&aux->mutex);
114}
115
116int
117nvkm_i2c_aux_acquire(struct nvkm_i2c_aux *aux)
118{
119	struct nvkm_i2c_pad *pad = aux->pad;
120	int ret;
121
122	AUX_TRACE(aux, "acquire");
123	mutex_lock(&aux->mutex);
124
125	if (aux->enabled)
126		ret = nvkm_i2c_pad_acquire(pad, NVKM_I2C_PAD_AUX);
127	else
128		ret = -EIO;
129
130	if (ret)
131		mutex_unlock(&aux->mutex);
132	return ret;
133}
134
135int
136nvkm_i2c_aux_xfer(struct nvkm_i2c_aux *aux, bool retry, u8 type,
137		  u32 addr, u8 *data, u8 *size)
138{
139	if (!*size && !aux->func->address_only) {
140		AUX_ERR(aux, "address-only transaction dropped");
141		return -ENOSYS;
142	}
143	return aux->func->xfer(aux, retry, type, addr, data, size);
144}
145
146int
147nvkm_i2c_aux_lnk_ctl(struct nvkm_i2c_aux *aux, int nr, int bw, bool ef)
148{
149	if (aux->func->lnk_ctl)
150		return aux->func->lnk_ctl(aux, nr, bw, ef);
151	return -ENODEV;
152}
153
154void
155nvkm_i2c_aux_del(struct nvkm_i2c_aux **paux)
156{
157	struct nvkm_i2c_aux *aux = *paux;
158	if (aux && !WARN_ON(!aux->func)) {
159		AUX_TRACE(aux, "dtor");
160		list_del(&aux->head);
161		i2c_del_adapter(&aux->i2c);
162		kfree(*paux);
163		*paux = NULL;
164	}
165}
166
167void
168nvkm_i2c_aux_init(struct nvkm_i2c_aux *aux)
169{
170	AUX_TRACE(aux, "init");
171	mutex_lock(&aux->mutex);
172	aux->enabled = true;
173	mutex_unlock(&aux->mutex);
174}
175
176void
177nvkm_i2c_aux_fini(struct nvkm_i2c_aux *aux)
178{
179	AUX_TRACE(aux, "fini");
180	mutex_lock(&aux->mutex);
181	aux->enabled = false;
182	mutex_unlock(&aux->mutex);
183}
184
185int
186nvkm_i2c_aux_ctor(const struct nvkm_i2c_aux_func *func,
187		  struct nvkm_i2c_pad *pad, int id,
188		  struct nvkm_i2c_aux *aux)
189{
190	struct nvkm_device *device = pad->i2c->subdev.device;
191
192	aux->func = func;
193	aux->pad = pad;
194	aux->id = id;
195	mutex_init(&aux->mutex);
196	list_add_tail(&aux->head, &pad->i2c->aux);
197	AUX_TRACE(aux, "ctor");
198
199	snprintf(aux->i2c.name, sizeof(aux->i2c.name), "nvkm-%s-aux-%04x",
200		 dev_name(device->dev), id);
201	aux->i2c.owner = THIS_MODULE;
202	aux->i2c.dev.parent = device->dev;
203	aux->i2c.algo = &nvkm_i2c_aux_i2c_algo;
204	return i2c_add_adapter(&aux->i2c);
205}
206
207int
208nvkm_i2c_aux_new_(const struct nvkm_i2c_aux_func *func,
209		  struct nvkm_i2c_pad *pad, int id,
210		  struct nvkm_i2c_aux **paux)
211{
212	if (!(*paux = kzalloc(sizeof(**paux), GFP_KERNEL)))
213		return -ENOMEM;
214	return nvkm_i2c_aux_ctor(func, pad, id, *paux);
215}
216