Merge master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb
[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@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  */
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@suse.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         init_MUTEX(&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 int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
110                           unsigned char addr, struct snd_i2c_device **rdevice)
111 {
112         struct snd_i2c_device *device;
113
114         *rdevice = NULL;
115         snd_assert(bus != NULL, return -EINVAL);
116         device = kzalloc(sizeof(*device), GFP_KERNEL);
117         if (device == NULL)
118                 return -ENOMEM;
119         device->addr = addr;
120         strlcpy(device->name, name, sizeof(device->name));
121         list_add_tail(&device->list, &bus->devices);
122         device->bus = bus;
123         *rdevice = device;
124         return 0;
125 }
126
127 int snd_i2c_device_free(struct snd_i2c_device *device)
128 {
129         if (device->bus)
130                 list_del(&device->list);
131         if (device->private_free)
132                 device->private_free(device);
133         kfree(device);
134         return 0;
135 }
136
137 int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
138 {
139         return device->bus->ops->sendbytes(device, bytes, count);
140 }
141
142
143 int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count)
144 {
145         return device->bus->ops->readbytes(device, bytes, count);
146 }
147
148 int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
149 {
150         return bus->ops->probeaddr(bus, addr);
151 }
152
153 /*
154  *  bit-operations
155  */
156
157 static inline void snd_i2c_bit_hw_start(struct snd_i2c_bus *bus)
158 {
159         if (bus->hw_ops.bit->start)
160                 bus->hw_ops.bit->start(bus);
161 }
162
163 static inline void snd_i2c_bit_hw_stop(struct snd_i2c_bus *bus)
164 {
165         if (bus->hw_ops.bit->stop)
166                 bus->hw_ops.bit->stop(bus);
167 }
168
169 static void snd_i2c_bit_direction(struct snd_i2c_bus *bus, int clock, int data)
170 {
171         if (bus->hw_ops.bit->direction)
172                 bus->hw_ops.bit->direction(bus, clock, data);
173 }
174
175 static void snd_i2c_bit_set(struct snd_i2c_bus *bus, int clock, int data)
176 {
177         bus->hw_ops.bit->setlines(bus, clock, data);
178 }
179
180 #if 0
181 static int snd_i2c_bit_clock(struct snd_i2c_bus *bus)
182 {
183         if (bus->hw_ops.bit->getclock)
184                 return bus->hw_ops.bit->getclock(bus);
185         return -ENXIO;
186 }
187 #endif
188
189 static int snd_i2c_bit_data(struct snd_i2c_bus *bus, int ack)
190 {
191         return bus->hw_ops.bit->getdata(bus, ack);
192 }
193
194 static void snd_i2c_bit_start(struct snd_i2c_bus *bus)
195 {
196         snd_i2c_bit_hw_start(bus);
197         snd_i2c_bit_direction(bus, 1, 1);       /* SCL - wr, SDA - wr */
198         snd_i2c_bit_set(bus, 1, 1);
199         snd_i2c_bit_set(bus, 1, 0);
200         snd_i2c_bit_set(bus, 0, 0);
201 }
202
203 static void snd_i2c_bit_stop(struct snd_i2c_bus *bus)
204 {
205         snd_i2c_bit_set(bus, 0, 0);
206         snd_i2c_bit_set(bus, 1, 0);
207         snd_i2c_bit_set(bus, 1, 1);
208         snd_i2c_bit_hw_stop(bus);
209 }
210
211 static void snd_i2c_bit_send(struct snd_i2c_bus *bus, int data)
212 {
213         snd_i2c_bit_set(bus, 0, data);
214         snd_i2c_bit_set(bus, 1, data);
215         snd_i2c_bit_set(bus, 0, data);
216 }
217
218 static int snd_i2c_bit_ack(struct snd_i2c_bus *bus)
219 {
220         int ack;
221
222         snd_i2c_bit_set(bus, 0, 1);
223         snd_i2c_bit_set(bus, 1, 1);
224         snd_i2c_bit_direction(bus, 1, 0);       /* SCL - wr, SDA - rd */
225         ack = snd_i2c_bit_data(bus, 1);
226         snd_i2c_bit_direction(bus, 1, 1);       /* SCL - wr, SDA - wr */
227         snd_i2c_bit_set(bus, 0, 1);
228         return ack ? -EIO : 0;
229 }
230
231 static int snd_i2c_bit_sendbyte(struct snd_i2c_bus *bus, unsigned char data)
232 {
233         int i, err;
234
235         for (i = 7; i >= 0; i--)
236                 snd_i2c_bit_send(bus, !!(data & (1 << i)));
237         if ((err = snd_i2c_bit_ack(bus)) < 0)
238                 return err;
239         return 0;
240 }
241
242 static int snd_i2c_bit_readbyte(struct snd_i2c_bus *bus, int last)
243 {
244         int i;
245         unsigned char data = 0;
246
247         snd_i2c_bit_set(bus, 0, 1);
248         snd_i2c_bit_direction(bus, 1, 0);       /* SCL - wr, SDA - rd */
249         for (i = 7; i >= 0; i--) {
250                 snd_i2c_bit_set(bus, 1, 1);
251                 if (snd_i2c_bit_data(bus, 0))
252                         data |= (1 << i);
253                 snd_i2c_bit_set(bus, 0, 1);
254         }
255         snd_i2c_bit_direction(bus, 1, 1);       /* SCL - wr, SDA - wr */
256         snd_i2c_bit_send(bus, !!last);
257         return data;
258 }
259
260 static int snd_i2c_bit_sendbytes(struct snd_i2c_device *device,
261                                  unsigned char *bytes, int count)
262 {
263         struct snd_i2c_bus *bus = device->bus;
264         int err, res = 0;
265
266         if (device->flags & SND_I2C_DEVICE_ADDRTEN)
267                 return -EIO;            /* not yet implemented */
268         snd_i2c_bit_start(bus);
269         if ((err = snd_i2c_bit_sendbyte(bus, device->addr << 1)) < 0) {
270                 snd_i2c_bit_hw_stop(bus);
271                 return err;
272         }
273         while (count-- > 0) {
274                 if ((err = snd_i2c_bit_sendbyte(bus, *bytes++)) < 0) {
275                         snd_i2c_bit_hw_stop(bus);
276                         return err;
277                 }
278                 res++;
279         }
280         snd_i2c_bit_stop(bus);
281         return res;
282 }
283
284 static int snd_i2c_bit_readbytes(struct snd_i2c_device *device,
285                                  unsigned char *bytes, int count)
286 {
287         struct snd_i2c_bus *bus = device->bus;
288         int err, res = 0;
289
290         if (device->flags & SND_I2C_DEVICE_ADDRTEN)
291                 return -EIO;            /* not yet implemented */
292         snd_i2c_bit_start(bus);
293         if ((err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1)) < 0) {
294                 snd_i2c_bit_hw_stop(bus);
295                 return err;
296         }
297         while (count-- > 0) {
298                 if ((err = snd_i2c_bit_readbyte(bus, count == 0)) < 0) {
299                         snd_i2c_bit_hw_stop(bus);
300                         return err;
301                 }
302                 *bytes++ = (unsigned char)err;
303                 res++;
304         }
305         snd_i2c_bit_stop(bus);
306         return res;
307 }
308
309 static int snd_i2c_bit_probeaddr(struct snd_i2c_bus *bus, unsigned short addr)
310 {
311         int err;
312
313         if (addr & 0x8000)      /* 10-bit address */
314                 return -EIO;    /* not yet implemented */
315         if (addr & 0x7f80)      /* invalid address */
316                 return -EINVAL;
317         snd_i2c_bit_start(bus);
318         err = snd_i2c_bit_sendbyte(bus, addr << 1);
319         snd_i2c_bit_stop(bus);
320         return err;
321 }
322
323 EXPORT_SYMBOL(snd_i2c_bus_create);
324 EXPORT_SYMBOL(snd_i2c_device_create);
325 EXPORT_SYMBOL(snd_i2c_device_free);
326 EXPORT_SYMBOL(snd_i2c_sendbytes);
327 EXPORT_SYMBOL(snd_i2c_readbytes);
328 EXPORT_SYMBOL(snd_i2c_probeaddr);
329
330 static int __init alsa_i2c_init(void)
331 {
332         return 0;
333 }
334
335 static void __exit alsa_i2c_exit(void)
336 {
337 }
338
339 module_init(alsa_i2c_init)
340 module_exit(alsa_i2c_exit)