1 /* $NetBSD: nouveau_nvkm_subdev_i2c_bus.c,v 1.5 2021/12/18 23:45:40 riastradh Exp $ */
2
3 /*
4 * Copyright 2015 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 <bskeggs@redhat.com>
25 */
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_i2c_bus.c,v 1.5 2021/12/18 23:45:40 riastradh Exp $");
28
29 #include "bus.h"
30 #include "pad.h"
31
32 #include <core/option.h>
33
34 #include <linux/nbsd-namespace.h>
35
36 /*******************************************************************************
37 * i2c-algo-bit
38 ******************************************************************************/
39 static int
nvkm_i2c_bus_pre_xfer(struct i2c_adapter * adap)40 nvkm_i2c_bus_pre_xfer(struct i2c_adapter *adap)
41 {
42 struct nvkm_i2c_bus *bus = container_of(adap, typeof(*bus), i2c);
43 return nvkm_i2c_bus_acquire(bus);
44 }
45
46 static void
nvkm_i2c_bus_post_xfer(struct i2c_adapter * adap)47 nvkm_i2c_bus_post_xfer(struct i2c_adapter *adap)
48 {
49 struct nvkm_i2c_bus *bus = container_of(adap, typeof(*bus), i2c);
50 return nvkm_i2c_bus_release(bus);
51 }
52
53 static void
nvkm_i2c_bus_setscl(void * data,int state)54 nvkm_i2c_bus_setscl(void *data, int state)
55 {
56 struct nvkm_i2c_bus *bus = data;
57 bus->func->drive_scl(bus, state);
58 }
59
60 static void
nvkm_i2c_bus_setsda(void * data,int state)61 nvkm_i2c_bus_setsda(void *data, int state)
62 {
63 struct nvkm_i2c_bus *bus = data;
64 bus->func->drive_sda(bus, state);
65 }
66
67 static int
nvkm_i2c_bus_getscl(void * data)68 nvkm_i2c_bus_getscl(void *data)
69 {
70 struct nvkm_i2c_bus *bus = data;
71 return bus->func->sense_scl(bus);
72 }
73
74 static int
nvkm_i2c_bus_getsda(void * data)75 nvkm_i2c_bus_getsda(void *data)
76 {
77 struct nvkm_i2c_bus *bus = data;
78 return bus->func->sense_sda(bus);
79 }
80
81 /*******************************************************************************
82 * !i2c-algo-bit (off-chip i2c bus / hw i2c / internal bit-banging algo)
83 ******************************************************************************/
84 static int
nvkm_i2c_bus_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)85 nvkm_i2c_bus_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
86 {
87 struct nvkm_i2c_bus *bus = container_of(adap, typeof(*bus), i2c);
88 int ret;
89
90 ret = nvkm_i2c_bus_acquire(bus);
91 if (ret)
92 return ret;
93
94 ret = bus->func->xfer(bus, msgs, num);
95 nvkm_i2c_bus_release(bus);
96 return ret;
97 }
98
99 static u32
nvkm_i2c_bus_func(struct i2c_adapter * adap)100 nvkm_i2c_bus_func(struct i2c_adapter *adap)
101 {
102 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
103 }
104
105 static const struct i2c_algorithm
106 nvkm_i2c_bus_algo = {
107 .master_xfer = nvkm_i2c_bus_xfer,
108 .functionality = nvkm_i2c_bus_func,
109 };
110
111 /*******************************************************************************
112 * nvkm_i2c_bus base
113 ******************************************************************************/
114 void
nvkm_i2c_bus_init(struct nvkm_i2c_bus * bus)115 nvkm_i2c_bus_init(struct nvkm_i2c_bus *bus)
116 {
117 BUS_TRACE(bus, "init");
118 if (bus->func->init)
119 bus->func->init(bus);
120
121 mutex_lock(&bus->mutex);
122 bus->enabled = true;
123 mutex_unlock(&bus->mutex);
124 }
125
126 void
nvkm_i2c_bus_fini(struct nvkm_i2c_bus * bus)127 nvkm_i2c_bus_fini(struct nvkm_i2c_bus *bus)
128 {
129 BUS_TRACE(bus, "fini");
130 mutex_lock(&bus->mutex);
131 bus->enabled = false;
132 mutex_unlock(&bus->mutex);
133 }
134
135 void
nvkm_i2c_bus_release(struct nvkm_i2c_bus * bus)136 nvkm_i2c_bus_release(struct nvkm_i2c_bus *bus)
137 {
138 struct nvkm_i2c_pad *pad = bus->pad;
139 BUS_TRACE(bus, "release");
140 nvkm_i2c_pad_release(pad);
141 mutex_unlock(&bus->mutex);
142 }
143
144 int
nvkm_i2c_bus_acquire(struct nvkm_i2c_bus * bus)145 nvkm_i2c_bus_acquire(struct nvkm_i2c_bus *bus)
146 {
147 struct nvkm_i2c_pad *pad = bus->pad;
148 int ret;
149
150 BUS_TRACE(bus, "acquire");
151 mutex_lock(&bus->mutex);
152
153 if (bus->enabled)
154 ret = nvkm_i2c_pad_acquire(pad, NVKM_I2C_PAD_I2C);
155 else
156 ret = -EIO;
157
158 if (ret)
159 mutex_unlock(&bus->mutex);
160 return ret;
161 }
162
163 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)164 nvkm_i2c_bus_probe(struct nvkm_i2c_bus *bus, const char *what,
165 struct nvkm_i2c_bus_probe *info,
166 bool (*match)(struct nvkm_i2c_bus *,
167 struct i2c_board_info *, void *), void *data)
168 {
169 int i;
170
171 BUS_DBG(bus, "probing %ss", what);
172 for (i = 0; info[i].dev.addr; i++) {
173 u8 orig_udelay = 0;
174
175 if ((bus->i2c.algo == &i2c_bit_algo) && (info[i].udelay != 0)) {
176 struct i2c_algo_bit_data *algo = bus->i2c.algo_data;
177 BUS_DBG(bus, "%dms delay instead of %dms",
178 info[i].udelay, algo->udelay);
179 orig_udelay = algo->udelay;
180 algo->udelay = info[i].udelay;
181 }
182
183 if (nvkm_probe_i2c(&bus->i2c, info[i].dev.addr) &&
184 (!match || match(bus, &info[i].dev, data))) {
185 BUS_DBG(bus, "detected %s: %s",
186 what, info[i].dev.type);
187 return i;
188 }
189
190 if (orig_udelay) {
191 struct i2c_algo_bit_data *algo = bus->i2c.algo_data;
192 algo->udelay = orig_udelay;
193 }
194 }
195
196 BUS_DBG(bus, "no devices found.");
197 return -ENODEV;
198 }
199
200 void
nvkm_i2c_bus_del(struct nvkm_i2c_bus ** pbus)201 nvkm_i2c_bus_del(struct nvkm_i2c_bus **pbus)
202 {
203 struct nvkm_i2c_bus *bus = *pbus;
204 if (bus && !WARN_ON(!bus->func)) {
205 BUS_TRACE(bus, "dtor");
206 list_del(&bus->head);
207 i2c_del_adapter(&bus->i2c);
208 mutex_destroy(&bus->mutex);
209 kfree(bus->i2c.algo_data);
210 kfree(*pbus);
211 *pbus = NULL;
212 }
213 }
214
215 int
nvkm_i2c_bus_ctor(const struct nvkm_i2c_bus_func * func,struct nvkm_i2c_pad * pad,int id,struct nvkm_i2c_bus * bus)216 nvkm_i2c_bus_ctor(const struct nvkm_i2c_bus_func *func,
217 struct nvkm_i2c_pad *pad, int id,
218 struct nvkm_i2c_bus *bus)
219 {
220 struct nvkm_device *device = pad->i2c->subdev.device;
221 struct i2c_algo_bit_data *bit;
222 #ifndef CONFIG_NOUVEAU_I2C_INTERNAL_DEFAULT
223 const bool internal = false;
224 #else
225 const bool internal = true;
226 #endif
227 int ret;
228
229 bus->func = func;
230 bus->pad = pad;
231 bus->id = id;
232 mutex_init(&bus->mutex);
233 list_add_tail(&bus->head, &pad->i2c->bus);
234 BUS_TRACE(bus, "ctor");
235
236 snprintf(bus->i2c.name, sizeof(bus->i2c.name), "nvkm-%s-bus-%04x",
237 dev_name(device->dev), id);
238 bus->i2c.owner = THIS_MODULE;
239 bus->i2c.dev.parent = device->dev;
240
241 if ( bus->func->drive_scl &&
242 !nvkm_boolopt(device->cfgopt, "NvI2C", internal)) {
243 if (!(bit = kzalloc(sizeof(*bit), GFP_KERNEL)))
244 return -ENOMEM;
245 bit->udelay = 10;
246 bit->timeout = usecs_to_jiffies(2200);
247 bit->data = bus;
248 bit->pre_xfer = nvkm_i2c_bus_pre_xfer;
249 bit->post_xfer = nvkm_i2c_bus_post_xfer;
250 bit->setscl = nvkm_i2c_bus_setscl;
251 bit->setsda = nvkm_i2c_bus_setsda;
252 bit->getscl = nvkm_i2c_bus_getscl;
253 bit->getsda = nvkm_i2c_bus_getsda;
254 bus->i2c.algo_data = bit;
255 ret = i2c_bit_add_bus(&bus->i2c);
256 } else {
257 bus->i2c.algo = &nvkm_i2c_bus_algo;
258 ret = i2c_add_adapter(&bus->i2c);
259 }
260
261 return ret;
262 }
263
264 int
nvkm_i2c_bus_new_(const struct nvkm_i2c_bus_func * func,struct nvkm_i2c_pad * pad,int id,struct nvkm_i2c_bus ** pbus)265 nvkm_i2c_bus_new_(const struct nvkm_i2c_bus_func *func,
266 struct nvkm_i2c_pad *pad, int id,
267 struct nvkm_i2c_bus **pbus)
268 {
269 if (!(*pbus = kzalloc(sizeof(**pbus), GFP_KERNEL)))
270 return -ENOMEM;
271 return nvkm_i2c_bus_ctor(func, pad, id, *pbus);
272 }
273