nfsd4: typo logical vs bitwise negate for want_mask
[linux-btrfs-devel.git] / sound / i2c / i2c.c
blobeb7c7d05a7c123e30153b1d0de240bc7bd870277
1 /*
2 * Generic i2c interface for ALSA
4 * (c) 1998 Gerd Knorr <kraxel@cs.tu-berlin.de>
5 * Modified for the ALSA driver by Jaroslav Kysela <perex@perex.cz>
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.
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.
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
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>
30 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
31 MODULE_DESCRIPTION("Generic i2c interface for ALSA");
32 MODULE_LICENSE("GPL");
34 static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
35 unsigned char *bytes, int count);
36 static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
37 unsigned char *bytes, int count);
38 static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
39 unsigned short addr);
41 static 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,
47 static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
49 struct snd_i2c_bus *slave;
50 struct snd_i2c_device *device;
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);
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);
66 if (bus->private_free)
67 bus->private_free(bus);
68 kfree(bus);
69 return 0;
72 static int snd_i2c_bus_dev_free(struct snd_device *device)
74 struct snd_i2c_bus *bus = device->device_data;
75 return snd_i2c_bus_free(bus);
78 int snd_i2c_bus_create(struct snd_card *card, const char *name,
79 struct snd_i2c_bus *master, struct snd_i2c_bus **ri2c)
81 struct snd_i2c_bus *bus;
82 int err;
83 static struct snd_device_ops ops = {
84 .dev_free = snd_i2c_bus_dev_free,
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;
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;
106 *ri2c = bus;
107 return 0;
110 EXPORT_SYMBOL(snd_i2c_bus_create);
112 int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
113 unsigned char addr, struct snd_i2c_device **rdevice)
115 struct snd_i2c_device *device;
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;
131 EXPORT_SYMBOL(snd_i2c_device_create);
133 int snd_i2c_device_free(struct snd_i2c_device *device)
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;
143 EXPORT_SYMBOL(snd_i2c_device_free);
145 int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
147 return device->bus->ops->sendbytes(device, bytes, count);
150 EXPORT_SYMBOL(snd_i2c_sendbytes);
152 int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
154 return device->bus->ops->readbytes(device, bytes, count);
157 EXPORT_SYMBOL(snd_i2c_readbytes);
159 int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
161 return bus->ops->probeaddr(bus, addr);
164 EXPORT_SYMBOL(snd_i2c_probeaddr);
167 * bit-operations
170 static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
172 if (bus->hw_ops.bit->start)
173 bus->hw_ops.bit->start(bus);
176 static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
178 if (bus->hw_ops.bit->stop)
179 bus->hw_ops.bit->stop(bus);
182 static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
184 if (bus->hw_ops.bit->direction)
185 bus->hw_ops.bit->direction(bus, clock, data);
188 static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
190 bus->hw_ops.bit->setlines(bus, clock, data);
193 #if 0
194 static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
196 if (bus->hw_ops.bit->getclock)
197 return bus->hw_ops.bit->getclock(bus);
198 return -ENXIO;
200 #endif
202 static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
204 return bus->hw_ops.bit->getdata(bus, ack);
207 static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
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);
216 static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
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);
224 static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
226 snd_i2c_bit_set(bus, 0, data);
227 snd_i2c_bit_set(bus, 1, data);
228 snd_i2c_bit_set(bus, 0, data);
231 static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
233 int ack;
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;
244 static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
246 int i, err;
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;
256 static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
258 int i;
259 unsigned char data = 0;
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);
269 snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */
270 snd_i2c_bit_send(bus, !!last);
271 return data;
274 static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
275 unsigned char *bytes, int count)
277 struct snd_i2c_bus *bus = device->bus;
278 int err, res = 0;
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;
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;
294 res++;
296 snd_i2c_bit_stop(bus);
297 return res;
300 static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
301 unsigned char *bytes, int count)
303 struct snd_i2c_bus *bus = device->bus;
304 int err, res = 0;
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;
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;
320 *bytes++ = (unsigned char)err;
321 res++;
323 snd_i2c_bit_stop(bus);
324 return res;
327 static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
329 int err;
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;
342 static int __init alsa_i2c_init(void)
344 return 0;
347 static void __exit alsa_i2c_exit(void)
351 module_init(alsa_i2c_init)
352 module_exit(alsa_i2c_exit)