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1/*
2 * Generic i2c interface for ALSA
3 *
4 * (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
5 * Modified for the ALSA driver by Jaroslav Kysela <perex@perex.cz>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 */
22
23#include <linux/init.h>
24#include <linux/slab.h>
25#include <linux/string.h>
26#include <linux/errno.h>
27#include <sound/core.h>
28#include <sound/i2c.h>
29
30MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
31MODULE_DESCRIPTION("Generic i2c interface for ALSA");
32MODULE_LICENSE("GPL");
33
34static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
35 unsigned char *bytes, int count);
36static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
37 unsigned char *bytes, int count);
38static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
39 unsigned short addr);
40
41static struct snd_i2c_ops snd_i2c_bit_ops = {
42 .sendbytes = snd_i2c_bit_sendbytes,
43 .readbytes = snd_i2c_bit_readbytes,
44 .probeaddr = snd_i2c_bit_probeaddr,
45};
46
47static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
48{
49 struct snd_i2c_bus *slave;
50 struct snd_i2c_device *device;
51
52 if (snd_BUG_ON(!bus))
53 return -EINVAL;
54 while (!list_empty(&bus->devices)) {
55 device = snd_i2c_device(bus->devices.next);
56 snd_i2c_device_free(device);
57 }
58 if (bus->master)
59 list_del(&bus->buses);
60 else {
61 while (!list_empty(&bus->buses)) {
62 slave = snd_i2c_slave_bus(bus->buses.next);
63 snd_device_free(bus->card, slave);
64 }
65 }
66 if (bus->private_free)
67 bus->private_free(bus);
68 kfree(bus);
69 return 0;
70}
71
72static int snd_i2c_bus_dev_free(struct snd_device *device)
73{
74 struct snd_i2c_bus *bus = device->device_data;
75 return snd_i2c_bus_free(bus);
76}
77
78int snd_i2c_bus_create(struct snd_card *card, const char *name,
79 struct snd_i2c_bus *master, struct snd_i2c_bus **ri2c)
80{
81 struct snd_i2c_bus *bus;
82 int err;
83 static struct snd_device_ops ops = {
84 .dev_free = snd_i2c_bus_dev_free,
85 };
86
87 *ri2c = NULL;
88 bus = kzalloc(sizeof(*bus), GFP_KERNEL);
89 if (bus == NULL)
90 return -ENOMEM;
91 mutex_init(&bus->lock_mutex);
92 INIT_LIST_HEAD(&bus->devices);
93 INIT_LIST_HEAD(&bus->buses);
94 bus->card = card;
95 bus->ops = &snd_i2c_bit_ops;
96 if (master) {
97 list_add_tail(&bus->buses, &master->buses);
98 bus->master = master;
99 }
100 strlcpy(bus->name, name, sizeof(bus->name));
101 err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops);
102 if (err < 0) {
103 snd_i2c_bus_free(bus);
104 return err;
105 }
106 *ri2c = bus;
107 return 0;
108}
109
110EXPORT_SYMBOL(snd_i2c_bus_create);
111
112int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
113 unsigned char addr, struct snd_i2c_device **rdevice)
114{
115 struct snd_i2c_device *device;
116
117 *rdevice = NULL;
118 if (snd_BUG_ON(!bus))
119 return -EINVAL;
120 device = kzalloc(sizeof(*device), GFP_KERNEL);
121 if (device == NULL)
122 return -ENOMEM;
123 device->addr = addr;
124 strlcpy(device->name, name, sizeof(device->name));
125 list_add_tail(&device->list, &bus->devices);
126 device->bus = bus;
127 *rdevice = device;
128 return 0;
129}
130
131EXPORT_SYMBOL(snd_i2c_device_create);
132
133int snd_i2c_device_free(struct snd_i2c_device *device)
134{
135 if (device->bus)
136 list_del(&device->list);
137 if (device->private_free)
138 device->private_free(device);
139 kfree(device);
140 return 0;
141}
142
143EXPORT_SYMBOL(snd_i2c_device_free);
144
145int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
146{
147 return device->bus->ops->sendbytes(device, bytes, count);
148}
149
150EXPORT_SYMBOL(snd_i2c_sendbytes);
151
152int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
153{
154 return device->bus->ops->readbytes(device, bytes, count);
155}
156
157EXPORT_SYMBOL(snd_i2c_readbytes);
158
159int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
160{
161 return bus->ops->probeaddr(bus, addr);
162}
163
164EXPORT_SYMBOL(snd_i2c_probeaddr);
165
166/*
167 * bit-operations
168 */
169
170static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
171{
172 if (bus->hw_ops.bit->start)
173 bus->hw_ops.bit->start(bus);
174}
175
176static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
177{
178 if (bus->hw_ops.bit->stop)
179 bus->hw_ops.bit->stop(bus);
180}
181
182static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
183{
184 if (bus->hw_ops.bit->direction)
185 bus->hw_ops.bit->direction(bus, clock, data);
186}
187
188static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
189{
190 bus->hw_ops.bit->setlines(bus, clock, data);
191}
192
193#if 0
194static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
195{
196 if (bus->hw_ops.bit->getclock)
197 return bus->hw_ops.bit->getclock(bus);
198 return -ENXIO;
199}
200#endif
201
202static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
203{
204 return bus->hw_ops.bit->getdata(bus, ack);
205}
206
207static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
208{
209 snd_i2c_bit_hw_start(bus);
210 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
211 snd_i2c_bit_set(bus, 1, 1);
212 snd_i2c_bit_set(bus, 1, 0);
213 snd_i2c_bit_set(bus, 0, 0);
214}
215
216static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
217{
218 snd_i2c_bit_set(bus, 0, 0);
219 snd_i2c_bit_set(bus, 1, 0);
220 snd_i2c_bit_set(bus, 1, 1);
221 snd_i2c_bit_hw_stop(bus);
222}
223
224static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
225{
226 snd_i2c_bit_set(bus, 0, data);
227 snd_i2c_bit_set(bus, 1, data);
228 snd_i2c_bit_set(bus, 0, data);
229}
230
231static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
232{
233 int ack;
234
235 snd_i2c_bit_set(bus, 0, 1);
236 snd_i2c_bit_set(bus, 1, 1);
237 snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
238 ack = snd_i2c_bit_data(bus, 1);
239 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
240 snd_i2c_bit_set(bus, 0, 1);
241 return ack ? -EIO : 0;
242}
243
244static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
245{
246 int i, err;
247
248 for (i = 7; i >= 0; i--)
249 snd_i2c_bit_send(bus, !!(data & (1 << i)));
250 err = snd_i2c_bit_ack(bus);
251 if (err < 0)
252 return err;
253 return 0;
254}
255
256static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
257{
258 int i;
259 unsigned char data = 0;
260
261 snd_i2c_bit_set(bus, 0, 1);
262 snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
263 for (i = 7; i >= 0; i--) {
264 snd_i2c_bit_set(bus, 1, 1);
265 if (snd_i2c_bit_data(bus, 0))
266 data |= (1 << i);
267 snd_i2c_bit_set(bus, 0, 1);
268 }
269 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
270 snd_i2c_bit_send(bus, !!last);
271 return data;
272}
273
274static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
275 unsigned char *bytes, int count)
276{
277 struct snd_i2c_bus *bus = device->bus;
278 int err, res = 0;
279
280 if (device->flags & SND_I2C_DEVICE_ADDRTEN)
281 return -EIO; /* not yet implemented */
282 snd_i2c_bit_start(bus);
283 err = snd_i2c_bit_sendbyte(bus, device->addr << 1);
284 if (err < 0) {
285 snd_i2c_bit_hw_stop(bus);
286 return err;
287 }
288 while (count-- > 0) {
289 err = snd_i2c_bit_sendbyte(bus, *bytes++);
290 if (err < 0) {
291 snd_i2c_bit_hw_stop(bus);
292 return err;
293 }
294 res++;
295 }
296 snd_i2c_bit_stop(bus);
297 return res;
298}
299
300static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
301 unsigned char *bytes, int count)
302{
303 struct snd_i2c_bus *bus = device->bus;
304 int err, res = 0;
305
306 if (device->flags & SND_I2C_DEVICE_ADDRTEN)
307 return -EIO; /* not yet implemented */
308 snd_i2c_bit_start(bus);
309 err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1);
310 if (err < 0) {
311 snd_i2c_bit_hw_stop(bus);
312 return err;
313 }
314 while (count-- > 0) {
315 err = snd_i2c_bit_readbyte(bus, count == 0);
316 if (err < 0) {
317 snd_i2c_bit_hw_stop(bus);
318 return err;
319 }
320 *bytes++ = (unsigned char)err;
321 res++;
322 }
323 snd_i2c_bit_stop(bus);
324 return res;
325}
326
327static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
328{
329 int err;
330
331 if (addr & 0x8000) /* 10-bit address */
332 return -EIO; /* not yet implemented */
333 if (addr & 0x7f80) /* invalid address */
334 return -EINVAL;
335 snd_i2c_bit_start(bus);
336 err = snd_i2c_bit_sendbyte(bus, addr << 1);
337 snd_i2c_bit_stop(bus);
338 return err;
339}
340
341
342static int __init alsa_i2c_init(void)
343{
344 return 0;
345}
346
347static void __exit alsa_i2c_exit(void)
348{
349}
350
351module_init(alsa_i2c_init)
352module_exit(alsa_i2c_exit)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic i2c interface for ALSA
4 *
5 * (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
6 * Modified for the ALSA driver by Jaroslav Kysela <perex@perex.cz>
7 */
8
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/module.h>
12#include <linux/string.h>
13#include <linux/errno.h>
14#include <sound/core.h>
15#include <sound/i2c.h>
16
17MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
18MODULE_DESCRIPTION("Generic i2c interface for ALSA");
19MODULE_LICENSE("GPL");
20
21static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
22 unsigned char *bytes, int count);
23static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
24 unsigned char *bytes, int count);
25static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
26 unsigned short addr);
27
28static const struct snd_i2c_ops snd_i2c_bit_ops = {
29 .sendbytes = snd_i2c_bit_sendbytes,
30 .readbytes = snd_i2c_bit_readbytes,
31 .probeaddr = snd_i2c_bit_probeaddr,
32};
33
34static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
35{
36 struct snd_i2c_bus *slave;
37 struct snd_i2c_device *device;
38
39 if (snd_BUG_ON(!bus))
40 return -EINVAL;
41 while (!list_empty(&bus->devices)) {
42 device = snd_i2c_device(bus->devices.next);
43 snd_i2c_device_free(device);
44 }
45 if (bus->master)
46 list_del(&bus->buses);
47 else {
48 while (!list_empty(&bus->buses)) {
49 slave = snd_i2c_slave_bus(bus->buses.next);
50 snd_device_free(bus->card, slave);
51 }
52 }
53 if (bus->private_free)
54 bus->private_free(bus);
55 kfree(bus);
56 return 0;
57}
58
59static int snd_i2c_bus_dev_free(struct snd_device *device)
60{
61 struct snd_i2c_bus *bus = device->device_data;
62 return snd_i2c_bus_free(bus);
63}
64
65int snd_i2c_bus_create(struct snd_card *card, const char *name,
66 struct snd_i2c_bus *master, struct snd_i2c_bus **ri2c)
67{
68 struct snd_i2c_bus *bus;
69 int err;
70 static struct snd_device_ops ops = {
71 .dev_free = snd_i2c_bus_dev_free,
72 };
73
74 *ri2c = NULL;
75 bus = kzalloc(sizeof(*bus), GFP_KERNEL);
76 if (bus == NULL)
77 return -ENOMEM;
78 mutex_init(&bus->lock_mutex);
79 INIT_LIST_HEAD(&bus->devices);
80 INIT_LIST_HEAD(&bus->buses);
81 bus->card = card;
82 bus->ops = &snd_i2c_bit_ops;
83 if (master) {
84 list_add_tail(&bus->buses, &master->buses);
85 bus->master = master;
86 }
87 strlcpy(bus->name, name, sizeof(bus->name));
88 err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops);
89 if (err < 0) {
90 snd_i2c_bus_free(bus);
91 return err;
92 }
93 *ri2c = bus;
94 return 0;
95}
96
97EXPORT_SYMBOL(snd_i2c_bus_create);
98
99int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
100 unsigned char addr, struct snd_i2c_device **rdevice)
101{
102 struct snd_i2c_device *device;
103
104 *rdevice = NULL;
105 if (snd_BUG_ON(!bus))
106 return -EINVAL;
107 device = kzalloc(sizeof(*device), GFP_KERNEL);
108 if (device == NULL)
109 return -ENOMEM;
110 device->addr = addr;
111 strlcpy(device->name, name, sizeof(device->name));
112 list_add_tail(&device->list, &bus->devices);
113 device->bus = bus;
114 *rdevice = device;
115 return 0;
116}
117
118EXPORT_SYMBOL(snd_i2c_device_create);
119
120int snd_i2c_device_free(struct snd_i2c_device *device)
121{
122 if (device->bus)
123 list_del(&device->list);
124 if (device->private_free)
125 device->private_free(device);
126 kfree(device);
127 return 0;
128}
129
130EXPORT_SYMBOL(snd_i2c_device_free);
131
132int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
133{
134 return device->bus->ops->sendbytes(device, bytes, count);
135}
136
137EXPORT_SYMBOL(snd_i2c_sendbytes);
138
139int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
140{
141 return device->bus->ops->readbytes(device, bytes, count);
142}
143
144EXPORT_SYMBOL(snd_i2c_readbytes);
145
146int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
147{
148 return bus->ops->probeaddr(bus, addr);
149}
150
151EXPORT_SYMBOL(snd_i2c_probeaddr);
152
153/*
154 * bit-operations
155 */
156
157static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
158{
159 if (bus->hw_ops.bit->start)
160 bus->hw_ops.bit->start(bus);
161}
162
163static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
164{
165 if (bus->hw_ops.bit->stop)
166 bus->hw_ops.bit->stop(bus);
167}
168
169static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
170{
171 if (bus->hw_ops.bit->direction)
172 bus->hw_ops.bit->direction(bus, clock, data);
173}
174
175static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
176{
177 bus->hw_ops.bit->setlines(bus, clock, data);
178}
179
180#if 0
181static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
182{
183 if (bus->hw_ops.bit->getclock)
184 return bus->hw_ops.bit->getclock(bus);
185 return -ENXIO;
186}
187#endif
188
189static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
190{
191 return bus->hw_ops.bit->getdata(bus, ack);
192}
193
194static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
195{
196 snd_i2c_bit_hw_start(bus);
197 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
198 snd_i2c_bit_set(bus, 1, 1);
199 snd_i2c_bit_set(bus, 1, 0);
200 snd_i2c_bit_set(bus, 0, 0);
201}
202
203static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
204{
205 snd_i2c_bit_set(bus, 0, 0);
206 snd_i2c_bit_set(bus, 1, 0);
207 snd_i2c_bit_set(bus, 1, 1);
208 snd_i2c_bit_hw_stop(bus);
209}
210
211static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
212{
213 snd_i2c_bit_set(bus, 0, data);
214 snd_i2c_bit_set(bus, 1, data);
215 snd_i2c_bit_set(bus, 0, data);
216}
217
218static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
219{
220 int ack;
221
222 snd_i2c_bit_set(bus, 0, 1);
223 snd_i2c_bit_set(bus, 1, 1);
224 snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
225 ack = snd_i2c_bit_data(bus, 1);
226 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
227 snd_i2c_bit_set(bus, 0, 1);
228 return ack ? -EIO : 0;
229}
230
231static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
232{
233 int i, err;
234
235 for (i = 7; i >= 0; i--)
236 snd_i2c_bit_send(bus, !!(data & (1 << i)));
237 err = snd_i2c_bit_ack(bus);
238 if (err < 0)
239 return err;
240 return 0;
241}
242
243static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
244{
245 int i;
246 unsigned char data = 0;
247
248 snd_i2c_bit_set(bus, 0, 1);
249 snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
250 for (i = 7; i >= 0; i--) {
251 snd_i2c_bit_set(bus, 1, 1);
252 if (snd_i2c_bit_data(bus, 0))
253 data |= (1 << i);
254 snd_i2c_bit_set(bus, 0, 1);
255 }
256 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
257 snd_i2c_bit_send(bus, !!last);
258 return data;
259}
260
261static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
262 unsigned char *bytes, int count)
263{
264 struct snd_i2c_bus *bus = device->bus;
265 int err, res = 0;
266
267 if (device->flags & SND_I2C_DEVICE_ADDRTEN)
268 return -EIO; /* not yet implemented */
269 snd_i2c_bit_start(bus);
270 err = snd_i2c_bit_sendbyte(bus, device->addr << 1);
271 if (err < 0) {
272 snd_i2c_bit_hw_stop(bus);
273 return err;
274 }
275 while (count-- > 0) {
276 err = snd_i2c_bit_sendbyte(bus, *bytes++);
277 if (err < 0) {
278 snd_i2c_bit_hw_stop(bus);
279 return err;
280 }
281 res++;
282 }
283 snd_i2c_bit_stop(bus);
284 return res;
285}
286
287static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
288 unsigned char *bytes, int count)
289{
290 struct snd_i2c_bus *bus = device->bus;
291 int err, res = 0;
292
293 if (device->flags & SND_I2C_DEVICE_ADDRTEN)
294 return -EIO; /* not yet implemented */
295 snd_i2c_bit_start(bus);
296 err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1);
297 if (err < 0) {
298 snd_i2c_bit_hw_stop(bus);
299 return err;
300 }
301 while (count-- > 0) {
302 err = snd_i2c_bit_readbyte(bus, count == 0);
303 if (err < 0) {
304 snd_i2c_bit_hw_stop(bus);
305 return err;
306 }
307 *bytes++ = (unsigned char)err;
308 res++;
309 }
310 snd_i2c_bit_stop(bus);
311 return res;
312}
313
314static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
315{
316 int err;
317
318 if (addr & 0x8000) /* 10-bit address */
319 return -EIO; /* not yet implemented */
320 if (addr & 0x7f80) /* invalid address */
321 return -EINVAL;
322 snd_i2c_bit_start(bus);
323 err = snd_i2c_bit_sendbyte(bus, addr << 1);
324 snd_i2c_bit_stop(bus);
325 return err;
326}