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 "bus.h"
25 #include "pad.h"
26
27 #include <core/option.h>
28
29 /*******************************************************************************
30 * i2c-algo-bit
31 ******************************************************************************/
32 static int
nvkm_i2c_bus_pre_xfer(struct i2c_adapter * adap)33 nvkm_i2c_bus_pre_xfer(struct i2c_adapter *adap)
34 {
35 struct nvkm_i2c_bus *bus = container_of(adap, typeof(*bus), i2c);
36 return nvkm_i2c_bus_acquire(bus);
37 }
38
39 static void
nvkm_i2c_bus_post_xfer(struct i2c_adapter * adap)40 nvkm_i2c_bus_post_xfer(struct i2c_adapter *adap)
41 {
42 struct nvkm_i2c_bus *bus = container_of(adap, typeof(*bus), i2c);
43 return nvkm_i2c_bus_release(bus);
44 }
45
46 static void
nvkm_i2c_bus_setscl(void * data,int state)47 nvkm_i2c_bus_setscl(void *data, int state)
48 {
49 struct nvkm_i2c_bus *bus = data;
50 bus->func->drive_scl(bus, state);
51 }
52
53 static void
nvkm_i2c_bus_setsda(void * data,int state)54 nvkm_i2c_bus_setsda(void *data, int state)
55 {
56 struct nvkm_i2c_bus *bus = data;
57 bus->func->drive_sda(bus, state);
58 }
59
60 static int
nvkm_i2c_bus_getscl(void * data)61 nvkm_i2c_bus_getscl(void *data)
62 {
63 struct nvkm_i2c_bus *bus = data;
64 return bus->func->sense_scl(bus);
65 }
66
67 static int
nvkm_i2c_bus_getsda(void * data)68 nvkm_i2c_bus_getsda(void *data)
69 {
70 struct nvkm_i2c_bus *bus = data;
71 return bus->func->sense_sda(bus);
72 }
73
74 /*******************************************************************************
75 * !i2c-algo-bit (off-chip i2c bus / hw i2c / internal bit-banging algo)
76 ******************************************************************************/
77 static int
nvkm_i2c_bus_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)78 nvkm_i2c_bus_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
79 {
80 struct nvkm_i2c_bus *bus = container_of(adap, typeof(*bus), i2c);
81 int ret;
82
83 ret = nvkm_i2c_bus_acquire(bus);
84 if (ret)
85 return ret;
86
87 ret = bus->func->xfer(bus, msgs, num);
88 nvkm_i2c_bus_release(bus);
89 return ret;
90 }
91
92 static u32
nvkm_i2c_bus_func(struct i2c_adapter * adap)93 nvkm_i2c_bus_func(struct i2c_adapter *adap)
94 {
95 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
96 }
97
98 static const struct i2c_algorithm
99 nvkm_i2c_bus_algo = {
100 .master_xfer = nvkm_i2c_bus_xfer,
101 .functionality = nvkm_i2c_bus_func,
102 };
103
104 /*******************************************************************************
105 * nvkm_i2c_bus base
106 ******************************************************************************/
107 void
nvkm_i2c_bus_init(struct nvkm_i2c_bus * bus)108 nvkm_i2c_bus_init(struct nvkm_i2c_bus *bus)
109 {
110 BUS_TRACE(bus, "init");
111 if (bus->func->init)
112 bus->func->init(bus);
113 }
114
115 void
nvkm_i2c_bus_release(struct nvkm_i2c_bus * bus)116 nvkm_i2c_bus_release(struct nvkm_i2c_bus *bus)
117 {
118 struct nvkm_i2c_pad *pad = bus->pad;
119 BUS_TRACE(bus, "release");
120 nvkm_i2c_pad_release(pad);
121 mutex_unlock(&bus->mutex);
122 }
123
124 int
nvkm_i2c_bus_acquire(struct nvkm_i2c_bus * bus)125 nvkm_i2c_bus_acquire(struct nvkm_i2c_bus *bus)
126 {
127 struct nvkm_i2c_pad *pad = bus->pad;
128 int ret;
129 BUS_TRACE(bus, "acquire");
130 mutex_lock(&bus->mutex);
131 ret = nvkm_i2c_pad_acquire(pad, NVKM_I2C_PAD_I2C);
132 if (ret)
133 mutex_unlock(&bus->mutex);
134 return ret;
135 }
136
137 int
nvkm_i2c_bus_probe(struct nvkm_i2c_bus * bus,const char * what,struct nvkm_i2c_bus_probe * info,bool (* match)(struct nvkm_i2c_bus *,struct i2c_board_info *,void *),void * data)138 nvkm_i2c_bus_probe(struct nvkm_i2c_bus *bus, const char *what,
139 struct nvkm_i2c_bus_probe *info,
140 bool (*match)(struct nvkm_i2c_bus *,
141 struct i2c_board_info *, void *), void *data)
142 {
143 int i;
144
145 BUS_DBG(bus, "probing %ss", what);
146 for (i = 0; info[i].dev.addr; i++) {
147 u8 orig_udelay = 0;
148
149 if ((bus->i2c.algo == &i2c_bit_algo) && (info[i].udelay != 0)) {
150 struct i2c_algo_bit_data *algo = bus->i2c.algo_data;
151 BUS_DBG(bus, "%dms delay instead of %dms",
152 info[i].udelay, algo->udelay);
153 orig_udelay = algo->udelay;
154 algo->udelay = info[i].udelay;
155 }
156
157 if (nvkm_probe_i2c(&bus->i2c, info[i].dev.addr) &&
158 (!match || match(bus, &info[i].dev, data))) {
159 BUS_DBG(bus, "detected %s: %s",
160 what, info[i].dev.type);
161 return i;
162 }
163
164 if (orig_udelay) {
165 struct i2c_algo_bit_data *algo = bus->i2c.algo_data;
166 algo->udelay = orig_udelay;
167 }
168 }
169
170 BUS_DBG(bus, "no devices found.");
171 return -ENODEV;
172 }
173
174 void
nvkm_i2c_bus_del(struct nvkm_i2c_bus ** pbus)175 nvkm_i2c_bus_del(struct nvkm_i2c_bus **pbus)
176 {
177 struct nvkm_i2c_bus *bus = *pbus;
178 if (bus && !WARN_ON(!bus->func)) {
179 BUS_TRACE(bus, "dtor");
180 list_del(&bus->head);
181 i2c_del_adapter(&bus->i2c);
182 kfree(bus->i2c.algo_data);
183 kfree(*pbus);
184 *pbus = NULL;
185 }
186 }
187
188 int
nvkm_i2c_bus_ctor(const struct nvkm_i2c_bus_func * func,struct nvkm_i2c_pad * pad,int id,struct nvkm_i2c_bus * bus)189 nvkm_i2c_bus_ctor(const struct nvkm_i2c_bus_func *func,
190 struct nvkm_i2c_pad *pad, int id,
191 struct nvkm_i2c_bus *bus)
192 {
193 struct nvkm_device *device = pad->i2c->subdev.device;
194 struct i2c_algo_bit_data *bit;
195 #ifndef CONFIG_NOUVEAU_I2C_INTERNAL_DEFAULT
196 const bool internal = false;
197 #else
198 const bool internal = true;
199 #endif
200 int ret;
201
202 bus->func = func;
203 bus->pad = pad;
204 bus->id = id;
205 mutex_init(&bus->mutex);
206 list_add_tail(&bus->head, &pad->i2c->bus);
207 BUS_TRACE(bus, "ctor");
208
209 snprintf(bus->i2c.name, sizeof(bus->i2c.name), "nvkm-%s-bus-%04x",
210 dev_name(device->dev), id);
211 bus->i2c.owner = THIS_MODULE;
212 bus->i2c.dev.parent = device->dev;
213
214 if ( bus->func->drive_scl &&
215 !nvkm_boolopt(device->cfgopt, "NvI2C", internal)) {
216 if (!(bit = kzalloc(sizeof(*bit), GFP_KERNEL)))
217 return -ENOMEM;
218 bit->udelay = 10;
219 bit->timeout = usecs_to_jiffies(2200);
220 bit->data = bus;
221 bit->pre_xfer = nvkm_i2c_bus_pre_xfer;
222 bit->post_xfer = nvkm_i2c_bus_post_xfer;
223 bit->setscl = nvkm_i2c_bus_setscl;
224 bit->setsda = nvkm_i2c_bus_setsda;
225 bit->getscl = nvkm_i2c_bus_getscl;
226 bit->getsda = nvkm_i2c_bus_getsda;
227 bus->i2c.algo_data = bit;
228 ret = i2c_bit_add_bus(&bus->i2c);
229 } else {
230 bus->i2c.algo = &nvkm_i2c_bus_algo;
231 ret = i2c_add_adapter(&bus->i2c);
232 }
233
234 return ret;
235 }
236
237 int
nvkm_i2c_bus_new_(const struct nvkm_i2c_bus_func * func,struct nvkm_i2c_pad * pad,int id,struct nvkm_i2c_bus ** pbus)238 nvkm_i2c_bus_new_(const struct nvkm_i2c_bus_func *func,
239 struct nvkm_i2c_pad *pad, int id,
240 struct nvkm_i2c_bus **pbus)
241 {
242 if (!(*pbus = kzalloc(sizeof(**pbus), GFP_KERNEL)))
243 return -ENOMEM;
244 return nvkm_i2c_bus_ctor(func, pad, id, *pbus);
245 }
246