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