blob: eb7c7d05a7c123e30153b1d0de240bc7bd870277 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Generic i2c interface for ALSA
3 *
4 * (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
Jaroslav Kyselac1017a42007-10-15 09:50:19 +02005 * Modified for the ALSA driver by Jaroslav Kysela <perex@perex.cz>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#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
Jaroslav Kyselac1017a42007-10-15 09:50:19 +020030MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
Linus Torvalds1da177e2005-04-16 15:20:36 -070031MODULE_DESCRIPTION("Generic i2c interface for ALSA");
32MODULE_LICENSE("GPL");
33
Takashi Iwai97f02e02005-11-17 14:17:19 +010034static 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
Takashi Iwai97f02e02005-11-17 14:17:19 +010041static struct snd_i2c_ops snd_i2c_bit_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 .sendbytes = snd_i2c_bit_sendbytes,
43 .readbytes = snd_i2c_bit_readbytes,
44 .probeaddr = snd_i2c_bit_probeaddr,
45};
46
Takashi Iwai97f02e02005-11-17 14:17:19 +010047static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
Takashi Iwai97f02e02005-11-17 14:17:19 +010049 struct snd_i2c_bus *slave;
50 struct snd_i2c_device *device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Takashi Iwai5e246b82008-08-08 17:12:47 +020052 if (snd_BUG_ON(!bus))
53 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 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
Takashi Iwai97f02e02005-11-17 14:17:19 +010072static int snd_i2c_bus_dev_free(struct snd_device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073{
Takashi Iwai97f02e02005-11-17 14:17:19 +010074 struct snd_i2c_bus *bus = device->device_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 return snd_i2c_bus_free(bus);
76}
77
Takashi Iwai97f02e02005-11-17 14:17:19 +010078int snd_i2c_bus_create(struct snd_card *card, const char *name,
79 struct snd_i2c_bus *master, struct snd_i2c_bus **ri2c)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
Takashi Iwai97f02e02005-11-17 14:17:19 +010081 struct snd_i2c_bus *bus;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 int err;
Takashi Iwai97f02e02005-11-17 14:17:19 +010083 static struct snd_device_ops ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 .dev_free = snd_i2c_bus_dev_free,
85 };
86
87 *ri2c = NULL;
Takashi Iwai561b2202005-09-09 14:22:34 +020088 bus = kzalloc(sizeof(*bus), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 if (bus == NULL)
90 return -ENOMEM;
Ingo Molnaref9f0a42006-01-16 16:31:42 +010091 mutex_init(&bus->lock_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 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));
Brian Waters1cff3992010-04-15 04:03:29 -0400101 err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops);
102 if (err < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 snd_i2c_bus_free(bus);
104 return err;
105 }
106 *ri2c = bus;
107 return 0;
108}
109
Takashi Iwai57c65c12006-04-28 15:13:40 +0200110EXPORT_SYMBOL(snd_i2c_bus_create);
111
Takashi Iwai97f02e02005-11-17 14:17:19 +0100112int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
113 unsigned char addr, struct snd_i2c_device **rdevice)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114{
Takashi Iwai97f02e02005-11-17 14:17:19 +0100115 struct snd_i2c_device *device;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
117 *rdevice = NULL;
Takashi Iwai5e246b82008-08-08 17:12:47 +0200118 if (snd_BUG_ON(!bus))
119 return -EINVAL;
Takashi Iwai561b2202005-09-09 14:22:34 +0200120 device = kzalloc(sizeof(*device), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 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
Takashi Iwai57c65c12006-04-28 15:13:40 +0200131EXPORT_SYMBOL(snd_i2c_device_create);
132
Takashi Iwai97f02e02005-11-17 14:17:19 +0100133int snd_i2c_device_free(struct snd_i2c_device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134{
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
Takashi Iwai57c65c12006-04-28 15:13:40 +0200143EXPORT_SYMBOL(snd_i2c_device_free);
144
Takashi Iwai97f02e02005-11-17 14:17:19 +0100145int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146{
147 return device->bus->ops->sendbytes(device, bytes, count);
148}
149
Takashi Iwai57c65c12006-04-28 15:13:40 +0200150EXPORT_SYMBOL(snd_i2c_sendbytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
Takashi Iwai97f02e02005-11-17 14:17:19 +0100152int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153{
154 return device->bus->ops->readbytes(device, bytes, count);
155}
156
Takashi Iwai57c65c12006-04-28 15:13:40 +0200157EXPORT_SYMBOL(snd_i2c_readbytes);
158
Takashi Iwai97f02e02005-11-17 14:17:19 +0100159int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160{
161 return bus->ops->probeaddr(bus, addr);
162}
163
Takashi Iwai57c65c12006-04-28 15:13:40 +0200164EXPORT_SYMBOL(snd_i2c_probeaddr);
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166/*
167 * bit-operations
168 */
169
Takashi Iwai97f02e02005-11-17 14:17:19 +0100170static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171{
172 if (bus->hw_ops.bit->start)
173 bus->hw_ops.bit->start(bus);
174}
175
Takashi Iwai97f02e02005-11-17 14:17:19 +0100176static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177{
178 if (bus->hw_ops.bit->stop)
179 bus->hw_ops.bit->stop(bus);
180}
181
Takashi Iwai97f02e02005-11-17 14:17:19 +0100182static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183{
184 if (bus->hw_ops.bit->direction)
185 bus->hw_ops.bit->direction(bus, clock, data);
186}
187
Takashi Iwai97f02e02005-11-17 14:17:19 +0100188static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189{
190 bus->hw_ops.bit->setlines(bus, clock, data);
191}
192
193#if 0
Takashi Iwai97f02e02005-11-17 14:17:19 +0100194static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195{
196 if (bus->hw_ops.bit->getclock)
197 return bus->hw_ops.bit->getclock(bus);
198 return -ENXIO;
199}
200#endif
201
Takashi Iwai97f02e02005-11-17 14:17:19 +0100202static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203{
204 return bus->hw_ops.bit->getdata(bus, ack);
205}
206
Takashi Iwai97f02e02005-11-17 14:17:19 +0100207static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208{
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
Takashi Iwai97f02e02005-11-17 14:17:19 +0100216static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217{
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
Takashi Iwai97f02e02005-11-17 14:17:19 +0100224static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225{
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
Takashi Iwai97f02e02005-11-17 14:17:19 +0100231static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232{
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
Takashi Iwai97f02e02005-11-17 14:17:19 +0100244static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245{
246 int i, err;
247
248 for (i = 7; i >= 0; i--)
249 snd_i2c_bit_send(bus, !!(data & (1 << i)));
Brian Waters1cff3992010-04-15 04:03:29 -0400250 err = snd_i2c_bit_ack(bus);
251 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 return err;
253 return 0;
254}
255
Takashi Iwai97f02e02005-11-17 14:17:19 +0100256static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257{
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
Takashi Iwai97f02e02005-11-17 14:17:19 +0100274static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
275 unsigned char *bytes, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
Takashi Iwai97f02e02005-11-17 14:17:19 +0100277 struct snd_i2c_bus *bus = device->bus;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 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);
Brian Waters1cff3992010-04-15 04:03:29 -0400283 err = snd_i2c_bit_sendbyte(bus, device->addr << 1);
284 if (err < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 snd_i2c_bit_hw_stop(bus);
286 return err;
287 }
288 while (count-- > 0) {
Brian Waters1cff3992010-04-15 04:03:29 -0400289 err = snd_i2c_bit_sendbyte(bus, *bytes++);
290 if (err < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 snd_i2c_bit_hw_stop(bus);
292 return err;
293 }
294 res++;
295 }
296 snd_i2c_bit_stop(bus);
297 return res;
298}
299
Takashi Iwai97f02e02005-11-17 14:17:19 +0100300static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
301 unsigned char *bytes, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302{
Takashi Iwai97f02e02005-11-17 14:17:19 +0100303 struct snd_i2c_bus *bus = device->bus;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 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);
Brian Waters1cff3992010-04-15 04:03:29 -0400309 err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1);
310 if (err < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 snd_i2c_bit_hw_stop(bus);
312 return err;
313 }
314 while (count-- > 0) {
Brian Waters1cff3992010-04-15 04:03:29 -0400315 err = snd_i2c_bit_readbyte(bus, count == 0);
316 if (err < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 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
Takashi Iwai97f02e02005-11-17 14:17:19 +0100327static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328{
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
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)