ia64/linux-2.6.18-xen.hg

view sound/i2c/i2c.c @ 782:9ab1c319531f

merge with linux-2.6.18-xen.hg
author Isaku Yamahata <yamahata@valinux.co.jp>
date Wed Jan 28 13:07:23 2009 +0900 (2009-01-28)
parents 831230e53067
children
line source
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@suse.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 */
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>
31 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>");
32 MODULE_DESCRIPTION("Generic i2c interface for ALSA");
33 MODULE_LICENSE("GPL");
35 static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
36 unsigned char *bytes, int count);
37 static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
38 unsigned char *bytes, int count);
39 static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus,
40 unsigned short addr);
42 static 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 };
48 static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
49 {
50 struct snd_i2c_bus *slave;
51 struct snd_i2c_device *device;
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 }
72 static 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 }
78 int 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 };
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 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 }
109 EXPORT_SYMBOL(snd_i2c_bus_create);
111 int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
112 unsigned char addr, struct snd_i2c_device **rdevice)
113 {
114 struct snd_i2c_device *device;
116 *rdevice = NULL;
117 snd_assert(bus != NULL, return -EINVAL);
118 device = kzalloc(sizeof(*device), GFP_KERNEL);
119 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 }
129 EXPORT_SYMBOL(snd_i2c_device_create);
131 int snd_i2c_device_free(struct snd_i2c_device *device)
132 {
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 }
141 EXPORT_SYMBOL(snd_i2c_device_free);
143 int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
144 {
145 return device->bus->ops->sendbytes(device, bytes, count);
146 }
148 EXPORT_SYMBOL(snd_i2c_sendbytes);
150 int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
151 {
152 return device->bus->ops->readbytes(device, bytes, count);
153 }
155 EXPORT_SYMBOL(snd_i2c_readbytes);
157 int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
158 {
159 return bus->ops->probeaddr(bus, addr);
160 }
162 EXPORT_SYMBOL(snd_i2c_probeaddr);
164 /*
165 * bit-operations
166 */
168 static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
169 {
170 if (bus->hw_ops.bit->start)
171 bus->hw_ops.bit->start(bus);
172 }
174 static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
175 {
176 if (bus->hw_ops.bit->stop)
177 bus->hw_ops.bit->stop(bus);
178 }
180 static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
181 {
182 if (bus->hw_ops.bit->direction)
183 bus->hw_ops.bit->direction(bus, clock, data);
184 }
186 static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
187 {
188 bus->hw_ops.bit->setlines(bus, clock, data);
189 }
191 #if 0
192 static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
193 {
194 if (bus->hw_ops.bit->getclock)
195 return bus->hw_ops.bit->getclock(bus);
196 return -ENXIO;
197 }
198 #endif
200 static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
201 {
202 return bus->hw_ops.bit->getdata(bus, ack);
203 }
205 static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
206 {
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 }
214 static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
215 {
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 }
222 static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
223 {
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 }
229 static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
230 {
231 int ack;
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 }
242 static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
243 {
244 int i, err;
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 }
253 static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
254 {
255 int i;
256 unsigned char data = 0;
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 }
271 static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
272 unsigned char *bytes, int count)
273 {
274 struct snd_i2c_bus *bus = device->bus;
275 int err, res = 0;
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 }
295 static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
296 unsigned char *bytes, int count)
297 {
298 struct snd_i2c_bus *bus = device->bus;
299 int err, res = 0;
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 }
320 static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
321 {
322 int err;
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 }
335 static int __init alsa_i2c_init(void)
336 {
337 return 0;
338 }
340 static void __exit alsa_i2c_exit(void)
341 {
342 }
344 module_init(alsa_i2c_init)
345 module_exit(alsa_i2c_exit)