tty: pl2303 needs identifiers for Siemens S81 as well as EF81
[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 <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
30 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
31 MODULE_DESCRIPTION("Generic i2c interface for ALSA");
32 MODULE_LICENSE("GPL");
33
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);
40
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,
45 };
46
47 static int snd_i2c_bus_free(struct snd_i2c_bus *bus)
48 {
49         struct snd_i2c_bus *slave;
50         struct snd_i2c_device *device;
51
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);
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         if (snd_BUG_ON(!bus))
118                 return -EINVAL;
119         device = kzalloc(sizeof(*device), GFP_KERNEL);
120         if (device == NULL)
121                 return -ENOMEM;
122         device->addr = addr;
123         strlcpy(device->name, name, sizeof(device->name));
124         list_add_tail(&device->list, &bus->devices);
125         device->bus = bus;
126         *rdevice = device;
127         return 0;
128 }
129
130 EXPORT_SYMBOL(snd_i2c_device_create);
131
132 int snd_i2c_device_free(struct snd_i2c_device *device)
133 {
134         if (device->bus)
135                 list_del(&device->list);
136         if (device->private_free)
137                 device->private_free(device);
138         kfree(device);
139         return 0;
140 }
141
142 EXPORT_SYMBOL(snd_i2c_device_free);
143
144 int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
145 {
146         return device->bus->ops->sendbytes(device, bytes, count);
147 }
148
149 EXPORT_SYMBOL(snd_i2c_sendbytes);
150
151 int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
152 {
153         return device->bus->ops->readbytes(device, bytes, count);
154 }
155
156 EXPORT_SYMBOL(snd_i2c_readbytes);
157
158 int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
159 {
160         return bus->ops->probeaddr(bus, addr);
161 }
162
163 EXPORT_SYMBOL(snd_i2c_probeaddr);
164
165 /*
166  *  bit-operations
167  */
168
169 static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
170 {
171         if (bus->hw_ops.bit->start)
172                 bus->hw_ops.bit->start(bus);
173 }
174
175 static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
176 {
177         if (bus->hw_ops.bit->stop)
178                 bus->hw_ops.bit->stop(bus);
179 }
180
181 static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
182 {
183         if (bus->hw_ops.bit->direction)
184                 bus->hw_ops.bit->direction(bus, clock, data);
185 }
186
187 static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
188 {
189         bus->hw_ops.bit->setlines(bus, clock, data);
190 }
191
192 #if 0
193 static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
194 {
195         if (bus->hw_ops.bit->getclock)
196                 return bus->hw_ops.bit->getclock(bus);
197         return -ENXIO;
198 }
199 #endif
200
201 static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
202 {
203         return bus->hw_ops.bit->getdata(bus, ack);
204 }
205
206 static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
207 {
208         snd_i2c_bit_hw_start(bus);
209         snd_i2c_bit_direction(bus, 1, 1);       /* SCL - wr, SDA - wr */
210         snd_i2c_bit_set(bus, 1, 1);
211         snd_i2c_bit_set(bus, 1, 0);
212         snd_i2c_bit_set(bus, 0, 0);
213 }
214
215 static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
216 {
217         snd_i2c_bit_set(bus, 0, 0);
218         snd_i2c_bit_set(bus, 1, 0);
219         snd_i2c_bit_set(bus, 1, 1);
220         snd_i2c_bit_hw_stop(bus);
221 }
222
223 static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
224 {
225         snd_i2c_bit_set(bus, 0, data);
226         snd_i2c_bit_set(bus, 1, data);
227         snd_i2c_bit_set(bus, 0, data);
228 }
229
230 static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
231 {
232         int ack;
233
234         snd_i2c_bit_set(bus, 0, 1);
235         snd_i2c_bit_set(bus, 1, 1);
236         snd_i2c_bit_direction(bus, 1, 0);       /* SCL - wr, SDA - rd */
237         ack = snd_i2c_bit_data(bus, 1);
238         snd_i2c_bit_direction(bus, 1, 1);       /* SCL - wr, SDA - wr */
239         snd_i2c_bit_set(bus, 0, 1);
240         return ack ? -EIO : 0;
241 }
242
243 static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
244 {
245         int i, err;
246
247         for (i = 7; i >= 0; i--)
248                 snd_i2c_bit_send(bus, !!(data & (1 << i)));
249         if ((err = snd_i2c_bit_ack(bus)) < 0)
250                 return err;
251         return 0;
252 }
253
254 static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
255 {
256         int i;
257         unsigned char data = 0;
258
259         snd_i2c_bit_set(bus, 0, 1);
260         snd_i2c_bit_direction(bus, 1, 0);       /* SCL - wr, SDA - rd */
261         for (i = 7; i >= 0; i--) {
262                 snd_i2c_bit_set(bus, 1, 1);
263                 if (snd_i2c_bit_data(bus, 0))
264                         data |= (1 << i);
265                 snd_i2c_bit_set(bus, 0, 1);
266         }
267         snd_i2c_bit_direction(bus, 1, 1);       /* SCL - wr, SDA - wr */
268         snd_i2c_bit_send(bus, !!last);
269         return data;
270 }
271
272 static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
273                                  unsigned char *bytes, int count)
274 {
275         struct snd_i2c_bus *bus = device->bus;
276         int err, res = 0;
277
278         if (device->flags & SND_I2C_DEVICE_ADDRTEN)
279                 return -EIO;            /* not yet implemented */
280         snd_i2c_bit_start(bus);
281         if ((err = snd_i2c_bit_sendbyte(bus, device->addr << 1)) < 0) {
282                 snd_i2c_bit_hw_stop(bus);
283                 return err;
284         }
285         while (count-- > 0) {
286                 if ((err = snd_i2c_bit_sendbyte(bus, *bytes++)) < 0) {
287                         snd_i2c_bit_hw_stop(bus);
288                         return err;
289                 }
290                 res++;
291         }
292         snd_i2c_bit_stop(bus);
293         return res;
294 }
295
296 static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
297                                  unsigned char *bytes, int count)
298 {
299         struct snd_i2c_bus *bus = device->bus;
300         int err, res = 0;
301
302         if (device->flags & SND_I2C_DEVICE_ADDRTEN)
303                 return -EIO;            /* not yet implemented */
304         snd_i2c_bit_start(bus);
305         if ((err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1)) < 0) {
306                 snd_i2c_bit_hw_stop(bus);
307                 return err;
308         }
309         while (count-- > 0) {
310                 if ((err = snd_i2c_bit_readbyte(bus, count == 0)) < 0) {
311                         snd_i2c_bit_hw_stop(bus);
312                         return err;
313                 }
314                 *bytes++ = (unsigned char)err;
315                 res++;
316         }
317         snd_i2c_bit_stop(bus);
318         return res;
319 }
320
321 static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
322 {
323         int err;
324
325         if (addr & 0x8000)      /* 10-bit address */
326                 return -EIO;    /* not yet implemented */
327         if (addr & 0x7f80)      /* invalid address */
328                 return -EINVAL;
329         snd_i2c_bit_start(bus);
330         err = snd_i2c_bit_sendbyte(bus, addr << 1);
331         snd_i2c_bit_stop(bus);
332         return err;
333 }
334
335
336 static int __init alsa_i2c_init(void)
337 {
338         return 0;
339 }
340
341 static void __exit alsa_i2c_exit(void)
342 {
343 }
344
345 module_init(alsa_i2c_init)
346 module_exit(alsa_i2c_exit)