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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
23#include <sound/driver.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27#include <linux/errno.h>
28#include <sound/core.h>
29#include <sound/i2c.h>
30
Jaroslav Kyselac1017a42007-10-15 09:50:19 +020031MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
Linus Torvalds1da177e2005-04-16 15:20:36 -070032MODULE_DESCRIPTION("Generic i2c interface for ALSA");
33MODULE_LICENSE("GPL");
34
Takashi Iwai97f02e02005-11-17 14:17:19 +010035static 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Takashi Iwai97f02e02005-11-17 14:17:19 +010042static struct snd_i2c_ops snd_i2c_bit_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 .sendbytes = snd_i2c_bit_sendbytes,
44 .readbytes = snd_i2c_bit_readbytes,
45 .probeaddr = snd_i2c_bit_probeaddr,
46};
47
Takashi Iwai97f02e02005-11-17 14:17:19 +010048static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049{
Takashi Iwai97f02e02005-11-17 14:17:19 +010050 struct snd_i2c_bus *slave;
51 struct snd_i2c_device *device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53 snd_assert(bus != NULL, 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
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));
101 if ((err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops)) < 0) {
102 snd_i2c_bus_free(bus);
103 return err;
104 }
105 *ri2c = bus;
106 return 0;
107}
108
Takashi Iwai57c65c12006-04-28 15:13:40 +0200109EXPORT_SYMBOL(snd_i2c_bus_create);
110
Takashi Iwai97f02e02005-11-17 14:17:19 +0100111int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
112 unsigned char addr, struct snd_i2c_device **rdevice)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
Takashi Iwai97f02e02005-11-17 14:17:19 +0100114 struct snd_i2c_device *device;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
116 *rdevice = NULL;
117 snd_assert(bus != NULL, return -EINVAL);
Takashi Iwai561b2202005-09-09 14:22:34 +0200118 device = kzalloc(sizeof(*device), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 if (device == NULL)
120 return -ENOMEM;
121 device->addr = addr;
122 strlcpy(device->name, name, sizeof(device->name));
123 list_add_tail(&device->list, &bus->devices);
124 device->bus = bus;
125 *rdevice = device;
126 return 0;
127}
128
Takashi Iwai57c65c12006-04-28 15:13:40 +0200129EXPORT_SYMBOL(snd_i2c_device_create);
130
Takashi Iwai97f02e02005-11-17 14:17:19 +0100131int snd_i2c_device_free(struct snd_i2c_device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132{
133 if (device->bus)
134 list_del(&device->list);
135 if (device->private_free)
136 device->private_free(device);
137 kfree(device);
138 return 0;
139}
140
Takashi Iwai57c65c12006-04-28 15:13:40 +0200141EXPORT_SYMBOL(snd_i2c_device_free);
142
Takashi Iwai97f02e02005-11-17 14:17:19 +0100143int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
145 return device->bus->ops->sendbytes(device, bytes, count);
146}
147
Takashi Iwai57c65c12006-04-28 15:13:40 +0200148EXPORT_SYMBOL(snd_i2c_sendbytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
Takashi Iwai97f02e02005-11-17 14:17:19 +0100150int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151{
152 return device->bus->ops->readbytes(device, bytes, count);
153}
154
Takashi Iwai57c65c12006-04-28 15:13:40 +0200155EXPORT_SYMBOL(snd_i2c_readbytes);
156
Takashi Iwai97f02e02005-11-17 14:17:19 +0100157int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158{
159 return bus->ops->probeaddr(bus, addr);
160}
161
Takashi Iwai57c65c12006-04-28 15:13:40 +0200162EXPORT_SYMBOL(snd_i2c_probeaddr);
163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164/*
165 * bit-operations
166 */
167
Takashi Iwai97f02e02005-11-17 14:17:19 +0100168static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169{
170 if (bus->hw_ops.bit->start)
171 bus->hw_ops.bit->start(bus);
172}
173
Takashi Iwai97f02e02005-11-17 14:17:19 +0100174static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175{
176 if (bus->hw_ops.bit->stop)
177 bus->hw_ops.bit->stop(bus);
178}
179
Takashi Iwai97f02e02005-11-17 14:17:19 +0100180static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181{
182 if (bus->hw_ops.bit->direction)
183 bus->hw_ops.bit->direction(bus, clock, data);
184}
185
Takashi Iwai97f02e02005-11-17 14:17:19 +0100186static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187{
188 bus->hw_ops.bit->setlines(bus, clock, data);
189}
190
191#if 0
Takashi Iwai97f02e02005-11-17 14:17:19 +0100192static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193{
194 if (bus->hw_ops.bit->getclock)
195 return bus->hw_ops.bit->getclock(bus);
196 return -ENXIO;
197}
198#endif
199
Takashi Iwai97f02e02005-11-17 14:17:19 +0100200static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201{
202 return bus->hw_ops.bit->getdata(bus, ack);
203}
204
Takashi Iwai97f02e02005-11-17 14:17:19 +0100205static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206{
207 snd_i2c_bit_hw_start(bus);
208 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
209 snd_i2c_bit_set(bus, 1, 1);
210 snd_i2c_bit_set(bus, 1, 0);
211 snd_i2c_bit_set(bus, 0, 0);
212}
213
Takashi Iwai97f02e02005-11-17 14:17:19 +0100214static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215{
216 snd_i2c_bit_set(bus, 0, 0);
217 snd_i2c_bit_set(bus, 1, 0);
218 snd_i2c_bit_set(bus, 1, 1);
219 snd_i2c_bit_hw_stop(bus);
220}
221
Takashi Iwai97f02e02005-11-17 14:17:19 +0100222static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223{
224 snd_i2c_bit_set(bus, 0, data);
225 snd_i2c_bit_set(bus, 1, data);
226 snd_i2c_bit_set(bus, 0, data);
227}
228
Takashi Iwai97f02e02005-11-17 14:17:19 +0100229static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230{
231 int ack;
232
233 snd_i2c_bit_set(bus, 0, 1);
234 snd_i2c_bit_set(bus, 1, 1);
235 snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
236 ack = snd_i2c_bit_data(bus, 1);
237 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
238 snd_i2c_bit_set(bus, 0, 1);
239 return ack ? -EIO : 0;
240}
241
Takashi Iwai97f02e02005-11-17 14:17:19 +0100242static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243{
244 int i, err;
245
246 for (i = 7; i >= 0; i--)
247 snd_i2c_bit_send(bus, !!(data & (1 << i)));
248 if ((err = snd_i2c_bit_ack(bus)) < 0)
249 return err;
250 return 0;
251}
252
Takashi Iwai97f02e02005-11-17 14:17:19 +0100253static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254{
255 int i;
256 unsigned char data = 0;
257
258 snd_i2c_bit_set(bus, 0, 1);
259 snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */
260 for (i = 7; i >= 0; i--) {
261 snd_i2c_bit_set(bus, 1, 1);
262 if (snd_i2c_bit_data(bus, 0))
263 data |= (1 << i);
264 snd_i2c_bit_set(bus, 0, 1);
265 }
266 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
267 snd_i2c_bit_send(bus, !!last);
268 return data;
269}
270
Takashi Iwai97f02e02005-11-17 14:17:19 +0100271static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
272 unsigned char *bytes, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273{
Takashi Iwai97f02e02005-11-17 14:17:19 +0100274 struct snd_i2c_bus *bus = device->bus;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 int err, res = 0;
276
277 if (device->flags & SND_I2C_DEVICE_ADDRTEN)
278 return -EIO; /* not yet implemented */
279 snd_i2c_bit_start(bus);
280 if ((err = snd_i2c_bit_sendbyte(bus, device->addr << 1)) < 0) {
281 snd_i2c_bit_hw_stop(bus);
282 return err;
283 }
284 while (count-- > 0) {
285 if ((err = snd_i2c_bit_sendbyte(bus, *bytes++)) < 0) {
286 snd_i2c_bit_hw_stop(bus);
287 return err;
288 }
289 res++;
290 }
291 snd_i2c_bit_stop(bus);
292 return res;
293}
294
Takashi Iwai97f02e02005-11-17 14:17:19 +0100295static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
296 unsigned char *bytes, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297{
Takashi Iwai97f02e02005-11-17 14:17:19 +0100298 struct snd_i2c_bus *bus = device->bus;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 int err, res = 0;
300
301 if (device->flags & SND_I2C_DEVICE_ADDRTEN)
302 return -EIO; /* not yet implemented */
303 snd_i2c_bit_start(bus);
304 if ((err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1)) < 0) {
305 snd_i2c_bit_hw_stop(bus);
306 return err;
307 }
308 while (count-- > 0) {
309 if ((err = snd_i2c_bit_readbyte(bus, count == 0)) < 0) {
310 snd_i2c_bit_hw_stop(bus);
311 return err;
312 }
313 *bytes++ = (unsigned char)err;
314 res++;
315 }
316 snd_i2c_bit_stop(bus);
317 return res;
318}
319
Takashi Iwai97f02e02005-11-17 14:17:19 +0100320static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321{
322 int err;
323
324 if (addr & 0x8000) /* 10-bit address */
325 return -EIO; /* not yet implemented */
326 if (addr & 0x7f80) /* invalid address */
327 return -EINVAL;
328 snd_i2c_bit_start(bus);
329 err = snd_i2c_bit_sendbyte(bus, addr << 1);
330 snd_i2c_bit_stop(bus);
331 return err;
332}
333
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
335static int __init alsa_i2c_init(void)
336{
337 return 0;
338}
339
340static void __exit alsa_i2c_exit(void)
341{
342}
343
344module_init(alsa_i2c_init)
345module_exit(alsa_i2c_exit)