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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}
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/module.h>
26#include <linux/string.h>
27#include <linux/errno.h>
28#include <sound/core.h>
29#include <sound/i2c.h>
30
31MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
32MODULE_DESCRIPTION("Generic i2c interface for ALSA");
33MODULE_LICENSE("GPL");
34
35static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
36 unsigned char *bytes, int count);
37static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
38 unsigned char *bytes, int count);
39static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
40 unsigned short addr);
41
42static struct snd_i2c_ops snd_i2c_bit_ops = {
43 .sendbytes = snd_i2c_bit_sendbytes,
44 .readbytes = snd_i2c_bit_readbytes,
45 .probeaddr = snd_i2c_bit_probeaddr,
46};
47
48static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
49{
50 struct snd_i2c_bus *slave;
51 struct snd_i2c_device *device;
52
53 if (snd_BUG_ON(!bus))
54 return -EINVAL;
55 while (!list_empty(&bus->devices)) {
56 device = snd_i2c_device(bus->devices.next);
57 snd_i2c_device_free(device);
58 }
59 if (bus->master)
60 list_del(&bus->buses);
61 else {
62 while (!list_empty(&bus->buses)) {
63 slave = snd_i2c_slave_bus(bus->buses.next);
64 snd_device_free(bus->card, slave);
65 }
66 }
67 if (bus->private_free)
68 bus->private_free(bus);
69 kfree(bus);
70 return 0;
71}
72
73static int snd_i2c_bus_dev_free(struct snd_device *device)
74{
75 struct snd_i2c_bus *bus = device->device_data;
76 return snd_i2c_bus_free(bus);
77}
78
79int snd_i2c_bus_create(struct snd_card *card, const char *name,
80 struct snd_i2c_bus *master, struct snd_i2c_bus **ri2c)
81{
82 struct snd_i2c_bus *bus;
83 int err;
84 static struct snd_device_ops ops = {
85 .dev_free = snd_i2c_bus_dev_free,
86 };
87
88 *ri2c = NULL;
89 bus = kzalloc(sizeof(*bus), GFP_KERNEL);
90 if (bus == NULL)
91 return -ENOMEM;
92 mutex_init(&bus->lock_mutex);
93 INIT_LIST_HEAD(&bus->devices);
94 INIT_LIST_HEAD(&bus->buses);
95 bus->card = card;
96 bus->ops = &snd_i2c_bit_ops;
97 if (master) {
98 list_add_tail(&bus->buses, &master->buses);
99 bus->master = master;
100 }
101 strlcpy(bus->name, name, sizeof(bus->name));
102 err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops);
103 if (err < 0) {
104 snd_i2c_bus_free(bus);
105 return err;
106 }
107 *ri2c = bus;
108 return 0;
109}
110
111EXPORT_SYMBOL(snd_i2c_bus_create);
112
113int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
114 unsigned char addr, struct snd_i2c_device **rdevice)
115{
116 struct snd_i2c_device *device;
117
118 *rdevice = NULL;
119 if (snd_BUG_ON(!bus))
120 return -EINVAL;
121 device = kzalloc(sizeof(*device), GFP_KERNEL);
122 if (device == NULL)
123 return -ENOMEM;
124 device->addr = addr;
125 strlcpy(device->name, name, sizeof(device->name));
126 list_add_tail(&device->list, &bus->devices);
127 device->bus = bus;
128 *rdevice = device;
129 return 0;
130}
131
132EXPORT_SYMBOL(snd_i2c_device_create);
133
134int snd_i2c_device_free(struct snd_i2c_device *device)
135{
136 if (device->bus)
137 list_del(&device->list);
138 if (device->private_free)
139 device->private_free(device);
140 kfree(device);
141 return 0;
142}
143
144EXPORT_SYMBOL(snd_i2c_device_free);
145
146int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
147{
148 return device->bus->ops->sendbytes(device, bytes, count);
149}
150
151EXPORT_SYMBOL(snd_i2c_sendbytes);
152
153int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
154{
155 return device->bus->ops->readbytes(device, bytes, count);
156}
157
158EXPORT_SYMBOL(snd_i2c_readbytes);
159
160int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
161{
162 return bus->ops->probeaddr(bus, addr);
163}
164
165EXPORT_SYMBOL(snd_i2c_probeaddr);
166
167/*
168 * bit-operations
169 */
170
171static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
172{
173 if (bus->hw_ops.bit->start)
174 bus->hw_ops.bit->start(bus);
175}
176
177static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
178{
179 if (bus->hw_ops.bit->stop)
180 bus->hw_ops.bit->stop(bus);
181}
182
183static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
184{
185 if (bus->hw_ops.bit->direction)
186 bus->hw_ops.bit->direction(bus, clock, data);
187}
188
189static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
190{
191 bus->hw_ops.bit->setlines(bus, clock, data);
192}
193
194#if 0
195static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
196{
197 if (bus->hw_ops.bit->getclock)
198 return bus->hw_ops.bit->getclock(bus);
199 return -ENXIO;
200}
201#endif
202
203static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
204{
205 return bus->hw_ops.bit->getdata(bus, ack);
206}
207
208static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
209{
210 snd_i2c_bit_hw_start(bus);
211 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
212 snd_i2c_bit_set(bus, 1, 1);
213 snd_i2c_bit_set(bus, 1, 0);
214 snd_i2c_bit_set(bus, 0, 0);
215}
216
217static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
218{
219 snd_i2c_bit_set(bus, 0, 0);
220 snd_i2c_bit_set(bus, 1, 0);
221 snd_i2c_bit_set(bus, 1, 1);
222 snd_i2c_bit_hw_stop(bus);
223}
224
225static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
226{
227 snd_i2c_bit_set(bus, 0, data);
228 snd_i2c_bit_set(bus, 1, data);
229 snd_i2c_bit_set(bus, 0, data);
230}
231
232static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
233{
234 int ack;
235
236 snd_i2c_bit_set(bus, 0, 1);
237 snd_i2c_bit_set(bus, 1, 1);
238 snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
239 ack = snd_i2c_bit_data(bus, 1);
240 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
241 snd_i2c_bit_set(bus, 0, 1);
242 return ack ? -EIO : 0;
243}
244
245static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
246{
247 int i, err;
248
249 for (i = 7; i >= 0; i--)
250 snd_i2c_bit_send(bus, !!(data & (1 << i)));
251 err = snd_i2c_bit_ack(bus);
252 if (err < 0)
253 return err;
254 return 0;
255}
256
257static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
258{
259 int i;
260 unsigned char data = 0;
261
262 snd_i2c_bit_set(bus, 0, 1);
263 snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
264 for (i = 7; i >= 0; i--) {
265 snd_i2c_bit_set(bus, 1, 1);
266 if (snd_i2c_bit_data(bus, 0))
267 data |= (1 << i);
268 snd_i2c_bit_set(bus, 0, 1);
269 }
270 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
271 snd_i2c_bit_send(bus, !!last);
272 return data;
273}
274
275static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
276 unsigned char *bytes, int count)
277{
278 struct snd_i2c_bus *bus = device->bus;
279 int err, res = 0;
280
281 if (device->flags & SND_I2C_DEVICE_ADDRTEN)
282 return -EIO; /* not yet implemented */
283 snd_i2c_bit_start(bus);
284 err = snd_i2c_bit_sendbyte(bus, device->addr << 1);
285 if (err < 0) {
286 snd_i2c_bit_hw_stop(bus);
287 return err;
288 }
289 while (count-- > 0) {
290 err = snd_i2c_bit_sendbyte(bus, *bytes++);
291 if (err < 0) {
292 snd_i2c_bit_hw_stop(bus);
293 return err;
294 }
295 res++;
296 }
297 snd_i2c_bit_stop(bus);
298 return res;
299}
300
301static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
302 unsigned char *bytes, int count)
303{
304 struct snd_i2c_bus *bus = device->bus;
305 int err, res = 0;
306
307 if (device->flags & SND_I2C_DEVICE_ADDRTEN)
308 return -EIO; /* not yet implemented */
309 snd_i2c_bit_start(bus);
310 err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1);
311 if (err < 0) {
312 snd_i2c_bit_hw_stop(bus);
313 return err;
314 }
315 while (count-- > 0) {
316 err = snd_i2c_bit_readbyte(bus, count == 0);
317 if (err < 0) {
318 snd_i2c_bit_hw_stop(bus);
319 return err;
320 }
321 *bytes++ = (unsigned char)err;
322 res++;
323 }
324 snd_i2c_bit_stop(bus);
325 return res;
326}
327
328static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
329{
330 int err;
331
332 if (addr & 0x8000) /* 10-bit address */
333 return -EIO; /* not yet implemented */
334 if (addr & 0x7f80) /* invalid address */
335 return -EINVAL;
336 snd_i2c_bit_start(bus);
337 err = snd_i2c_bit_sendbyte(bus, addr << 1);
338 snd_i2c_bit_stop(bus);
339 return err;
340}
341
342
343static int __init alsa_i2c_init(void)
344{
345 return 0;
346}
347
348static void __exit alsa_i2c_exit(void)
349{
350}
351
352module_init(alsa_i2c_init)
353module_exit(alsa_i2c_exit)