1 /* $NetBSD: nouveau_nvkm_subdev_i2c_aux.c,v 1.5 2021/12/18 23:45:40 riastradh Exp $ */
2
3 /*
4 * Copyright 2009 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_i2c_aux.c,v 1.5 2021/12/18 23:45:40 riastradh Exp $");
28
29 #include "aux.h"
30 #include "pad.h"
31
32 #include <linux/nbsd-namespace.h>
33
34 static int
nvkm_i2c_aux_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)35 nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
36 {
37 struct nvkm_i2c_aux *aux = container_of(adap, typeof(*aux), i2c);
38 struct i2c_msg *msg = msgs;
39 int ret, mcnt = num;
40
41 ret = nvkm_i2c_aux_acquire(aux);
42 if (ret)
43 return ret;
44
45 while (mcnt--) {
46 u8 remaining = msg->len;
47 u8 *ptr = msg->buf;
48
49 while (remaining) {
50 u8 cnt, retries, cmd;
51
52 if (msg->flags & I2C_M_RD)
53 cmd = 1;
54 else
55 cmd = 0;
56
57 if (mcnt || remaining > 16)
58 cmd |= 4; /* MOT */
59
60 for (retries = 0, cnt = 0;
61 retries < 32 && !cnt;
62 retries++) {
63 cnt = min_t(u8, remaining, 16);
64 ret = aux->func->xfer(aux, true, cmd,
65 msg->addr, ptr, &cnt);
66 if (ret < 0)
67 goto out;
68 }
69 if (!cnt) {
70 AUX_TRACE(aux, "no data after 32 retries");
71 ret = -EIO;
72 goto out;
73 }
74
75 ptr += cnt;
76 remaining -= cnt;
77 }
78
79 msg++;
80 }
81
82 ret = num;
83 out:
84 nvkm_i2c_aux_release(aux);
85 return ret;
86 }
87
88 static u32
nvkm_i2c_aux_i2c_func(struct i2c_adapter * adap)89 nvkm_i2c_aux_i2c_func(struct i2c_adapter *adap)
90 {
91 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
92 }
93
94 static const struct i2c_algorithm
95 nvkm_i2c_aux_i2c_algo = {
96 .master_xfer = nvkm_i2c_aux_i2c_xfer,
97 .functionality = nvkm_i2c_aux_i2c_func
98 };
99
100 void
nvkm_i2c_aux_monitor(struct nvkm_i2c_aux * aux,bool monitor)101 nvkm_i2c_aux_monitor(struct nvkm_i2c_aux *aux, bool monitor)
102 {
103 struct nvkm_i2c_pad *pad = aux->pad;
104 AUX_TRACE(aux, "monitor: %s", monitor ? "yes" : "no");
105 if (monitor)
106 nvkm_i2c_pad_mode(pad, NVKM_I2C_PAD_AUX);
107 else
108 nvkm_i2c_pad_mode(pad, NVKM_I2C_PAD_OFF);
109 }
110
111 void
nvkm_i2c_aux_release(struct nvkm_i2c_aux * aux)112 nvkm_i2c_aux_release(struct nvkm_i2c_aux *aux)
113 {
114 struct nvkm_i2c_pad *pad = aux->pad;
115 AUX_TRACE(aux, "release");
116 nvkm_i2c_pad_release(pad);
117 mutex_unlock(&aux->mutex);
118 }
119
120 int
nvkm_i2c_aux_acquire(struct nvkm_i2c_aux * aux)121 nvkm_i2c_aux_acquire(struct nvkm_i2c_aux *aux)
122 {
123 struct nvkm_i2c_pad *pad = aux->pad;
124 int ret;
125
126 AUX_TRACE(aux, "acquire");
127 mutex_lock(&aux->mutex);
128
129 if (aux->enabled)
130 ret = nvkm_i2c_pad_acquire(pad, NVKM_I2C_PAD_AUX);
131 else
132 ret = -EIO;
133
134 if (ret)
135 mutex_unlock(&aux->mutex);
136 return ret;
137 }
138
139 int
nvkm_i2c_aux_xfer(struct nvkm_i2c_aux * aux,bool retry,u8 type,u32 addr,u8 * data,u8 * size)140 nvkm_i2c_aux_xfer(struct nvkm_i2c_aux *aux, bool retry, u8 type,
141 u32 addr, u8 *data, u8 *size)
142 {
143 if (!*size && !aux->func->address_only) {
144 AUX_ERR(aux, "address-only transaction dropped");
145 return -ENOSYS;
146 }
147 return aux->func->xfer(aux, retry, type, addr, data, size);
148 }
149
150 int
nvkm_i2c_aux_lnk_ctl(struct nvkm_i2c_aux * aux,int nr,int bw,bool ef)151 nvkm_i2c_aux_lnk_ctl(struct nvkm_i2c_aux *aux, int nr, int bw, bool ef)
152 {
153 if (aux->func->lnk_ctl)
154 return aux->func->lnk_ctl(aux, nr, bw, ef);
155 return -ENODEV;
156 }
157
158 void
nvkm_i2c_aux_del(struct nvkm_i2c_aux ** paux)159 nvkm_i2c_aux_del(struct nvkm_i2c_aux **paux)
160 {
161 struct nvkm_i2c_aux *aux = *paux;
162 if (aux && !WARN_ON(!aux->func)) {
163 AUX_TRACE(aux, "dtor");
164 list_del(&aux->head);
165 i2c_del_adapter(&aux->i2c);
166 mutex_destroy(&aux->mutex);
167 kfree(*paux);
168 *paux = NULL;
169 }
170 }
171
172 void
nvkm_i2c_aux_init(struct nvkm_i2c_aux * aux)173 nvkm_i2c_aux_init(struct nvkm_i2c_aux *aux)
174 {
175 AUX_TRACE(aux, "init");
176 mutex_lock(&aux->mutex);
177 aux->enabled = true;
178 mutex_unlock(&aux->mutex);
179 }
180
181 void
nvkm_i2c_aux_fini(struct nvkm_i2c_aux * aux)182 nvkm_i2c_aux_fini(struct nvkm_i2c_aux *aux)
183 {
184 AUX_TRACE(aux, "fini");
185 mutex_lock(&aux->mutex);
186 aux->enabled = false;
187 mutex_unlock(&aux->mutex);
188 }
189
190 int
nvkm_i2c_aux_ctor(const struct nvkm_i2c_aux_func * func,struct nvkm_i2c_pad * pad,int id,struct nvkm_i2c_aux * aux)191 nvkm_i2c_aux_ctor(const struct nvkm_i2c_aux_func *func,
192 struct nvkm_i2c_pad *pad, int id,
193 struct nvkm_i2c_aux *aux)
194 {
195 struct nvkm_device *device = pad->i2c->subdev.device;
196
197 aux->func = func;
198 aux->pad = pad;
199 aux->id = id;
200 mutex_init(&aux->mutex);
201 list_add_tail(&aux->head, &pad->i2c->aux);
202 AUX_TRACE(aux, "ctor");
203
204 snprintf(aux->i2c.name, sizeof(aux->i2c.name), "nvkm-%s-aux-%04x",
205 dev_name(device->dev), id);
206 aux->i2c.owner = THIS_MODULE;
207 aux->i2c.dev.parent = device->dev;
208 aux->i2c.algo = &nvkm_i2c_aux_i2c_algo;
209 return i2c_add_adapter(&aux->i2c);
210 }
211
212 int
nvkm_i2c_aux_new_(const struct nvkm_i2c_aux_func * func,struct nvkm_i2c_pad * pad,int id,struct nvkm_i2c_aux ** paux)213 nvkm_i2c_aux_new_(const struct nvkm_i2c_aux_func *func,
214 struct nvkm_i2c_pad *pad, int id,
215 struct nvkm_i2c_aux **paux)
216 {
217 if (!(*paux = kzalloc(sizeof(**paux), GFP_KERNEL)))
218 return -ENOMEM;
219 return nvkm_i2c_aux_ctor(func, pad, id, *paux);
220 }
221