[ALSA] Changed Jaroslav Kysela's e-mail from perex@suse.cz to perex@perex.cz
[linux-2.6.git] / sound / i2c / i2c.c
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 <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
31 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
32 MODULE_DESCRIPTION("Generic i2c interface for ALSA");
33 MODULE_LICENSE("GPL");
34
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);
41
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 };
47
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;
52
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
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 }
77
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         };
86
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 }
108
109 EXPORT_SYMBOL(snd_i2c_bus_create);
110
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;
115
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 }
128
129 EXPORT_SYMBOL(snd_i2c_device_create);
130
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 }
140
141 EXPORT_SYMBOL(snd_i2c_device_free);
142
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 }
147
148 EXPORT_SYMBOL(snd_i2c_sendbytes);
149
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 }
154
155 EXPORT_SYMBOL(snd_i2c_readbytes);
156
157 int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
158 {
159         return bus->ops->probeaddr(bus, addr);
160 }
161
162 EXPORT_SYMBOL(snd_i2c_probeaddr);
163
164 /*
165  *  bit-operations
166  */
167
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 }
173
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 }
179
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 }
185
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 }
190
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
199
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 }
204
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 }
213
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 }
221
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 }
228
229 static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
230 {
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
242 static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
243 {
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
253 static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
254 {
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
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;
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
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;
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
320 static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
321 {
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
334
335 static int __init alsa_i2c_init(void)
336 {
337         return 0;
338 }
339
340 static void __exit alsa_i2c_exit(void)
341 {
342 }
343
344 module_init(alsa_i2c_init)
345 module_exit(alsa_i2c_exit)