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1da177e4 LT |
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(snd_i2c_device_t *device, unsigned char *bytes, int count); | |
36 | static int snd_i2c_bit_readbytes(snd_i2c_device_t *device, unsigned char *bytes, int count); | |
37 | static int snd_i2c_bit_probeaddr(snd_i2c_bus_t *bus, unsigned short addr); | |
38 | ||
39 | static snd_i2c_ops_t snd_i2c_bit_ops = { | |
40 | .sendbytes = snd_i2c_bit_sendbytes, | |
41 | .readbytes = snd_i2c_bit_readbytes, | |
42 | .probeaddr = snd_i2c_bit_probeaddr, | |
43 | }; | |
44 | ||
45 | static int snd_i2c_bus_free(snd_i2c_bus_t *bus) | |
46 | { | |
47 | snd_i2c_bus_t *slave; | |
48 | snd_i2c_device_t *device; | |
49 | ||
50 | snd_assert(bus != NULL, return -EINVAL); | |
51 | while (!list_empty(&bus->devices)) { | |
52 | device = snd_i2c_device(bus->devices.next); | |
53 | snd_i2c_device_free(device); | |
54 | } | |
55 | if (bus->master) | |
56 | list_del(&bus->buses); | |
57 | else { | |
58 | while (!list_empty(&bus->buses)) { | |
59 | slave = snd_i2c_slave_bus(bus->buses.next); | |
60 | snd_device_free(bus->card, slave); | |
61 | } | |
62 | } | |
63 | if (bus->private_free) | |
64 | bus->private_free(bus); | |
65 | kfree(bus); | |
66 | return 0; | |
67 | } | |
68 | ||
69 | static int snd_i2c_bus_dev_free(snd_device_t *device) | |
70 | { | |
71 | snd_i2c_bus_t *bus = device->device_data; | |
72 | return snd_i2c_bus_free(bus); | |
73 | } | |
74 | ||
75 | int snd_i2c_bus_create(snd_card_t *card, const char *name, snd_i2c_bus_t *master, snd_i2c_bus_t **ri2c) | |
76 | { | |
77 | snd_i2c_bus_t *bus; | |
78 | int err; | |
79 | static snd_device_ops_t ops = { | |
80 | .dev_free = snd_i2c_bus_dev_free, | |
81 | }; | |
82 | ||
83 | *ri2c = NULL; | |
561b220a | 84 | bus = kzalloc(sizeof(*bus), GFP_KERNEL); |
1da177e4 LT |
85 | if (bus == NULL) |
86 | return -ENOMEM; | |
87 | init_MUTEX(&bus->lock_mutex); | |
88 | INIT_LIST_HEAD(&bus->devices); | |
89 | INIT_LIST_HEAD(&bus->buses); | |
90 | bus->card = card; | |
91 | bus->ops = &snd_i2c_bit_ops; | |
92 | if (master) { | |
93 | list_add_tail(&bus->buses, &master->buses); | |
94 | bus->master = master; | |
95 | } | |
96 | strlcpy(bus->name, name, sizeof(bus->name)); | |
97 | if ((err = snd_device_new(card, SNDRV_DEV_BUS, bus, &ops)) < 0) { | |
98 | snd_i2c_bus_free(bus); | |
99 | return err; | |
100 | } | |
101 | *ri2c = bus; | |
102 | return 0; | |
103 | } | |
104 | ||
105 | int snd_i2c_device_create(snd_i2c_bus_t *bus, const char *name, unsigned char addr, snd_i2c_device_t **rdevice) | |
106 | { | |
107 | snd_i2c_device_t *device; | |
108 | ||
109 | *rdevice = NULL; | |
110 | snd_assert(bus != NULL, return -EINVAL); | |
561b220a | 111 | device = kzalloc(sizeof(*device), GFP_KERNEL); |
1da177e4 LT |
112 | if (device == NULL) |
113 | return -ENOMEM; | |
114 | device->addr = addr; | |
115 | strlcpy(device->name, name, sizeof(device->name)); | |
116 | list_add_tail(&device->list, &bus->devices); | |
117 | device->bus = bus; | |
118 | *rdevice = device; | |
119 | return 0; | |
120 | } | |
121 | ||
122 | int snd_i2c_device_free(snd_i2c_device_t *device) | |
123 | { | |
124 | if (device->bus) | |
125 | list_del(&device->list); | |
126 | if (device->private_free) | |
127 | device->private_free(device); | |
128 | kfree(device); | |
129 | return 0; | |
130 | } | |
131 | ||
132 | int snd_i2c_sendbytes(snd_i2c_device_t *device, unsigned char *bytes, int count) | |
133 | { | |
134 | return device->bus->ops->sendbytes(device, bytes, count); | |
135 | } | |
136 | ||
137 | ||
138 | int snd_i2c_readbytes(snd_i2c_device_t *device, unsigned char *bytes, int count) | |
139 | { | |
140 | return device->bus->ops->readbytes(device, bytes, count); | |
141 | } | |
142 | ||
143 | int snd_i2c_probeaddr(snd_i2c_bus_t *bus, unsigned short addr) | |
144 | { | |
145 | return bus->ops->probeaddr(bus, addr); | |
146 | } | |
147 | ||
148 | /* | |
149 | * bit-operations | |
150 | */ | |
151 | ||
152 | static inline void snd_i2c_bit_hw_start(snd_i2c_bus_t *bus) | |
153 | { | |
154 | if (bus->hw_ops.bit->start) | |
155 | bus->hw_ops.bit->start(bus); | |
156 | } | |
157 | ||
158 | static inline void snd_i2c_bit_hw_stop(snd_i2c_bus_t *bus) | |
159 | { | |
160 | if (bus->hw_ops.bit->stop) | |
161 | bus->hw_ops.bit->stop(bus); | |
162 | } | |
163 | ||
164 | static void snd_i2c_bit_direction(snd_i2c_bus_t *bus, int clock, int data) | |
165 | { | |
166 | if (bus->hw_ops.bit->direction) | |
167 | bus->hw_ops.bit->direction(bus, clock, data); | |
168 | } | |
169 | ||
170 | static void snd_i2c_bit_set(snd_i2c_bus_t *bus, int clock, int data) | |
171 | { | |
172 | bus->hw_ops.bit->setlines(bus, clock, data); | |
173 | } | |
174 | ||
175 | #if 0 | |
176 | static int snd_i2c_bit_clock(snd_i2c_bus_t *bus) | |
177 | { | |
178 | if (bus->hw_ops.bit->getclock) | |
179 | return bus->hw_ops.bit->getclock(bus); | |
180 | return -ENXIO; | |
181 | } | |
182 | #endif | |
183 | ||
184 | static int snd_i2c_bit_data(snd_i2c_bus_t *bus, int ack) | |
185 | { | |
186 | return bus->hw_ops.bit->getdata(bus, ack); | |
187 | } | |
188 | ||
189 | static void snd_i2c_bit_start(snd_i2c_bus_t *bus) | |
190 | { | |
191 | snd_i2c_bit_hw_start(bus); | |
192 | snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */ | |
193 | snd_i2c_bit_set(bus, 1, 1); | |
194 | snd_i2c_bit_set(bus, 1, 0); | |
195 | snd_i2c_bit_set(bus, 0, 0); | |
196 | } | |
197 | ||
198 | static void snd_i2c_bit_stop(snd_i2c_bus_t *bus) | |
199 | { | |
200 | snd_i2c_bit_set(bus, 0, 0); | |
201 | snd_i2c_bit_set(bus, 1, 0); | |
202 | snd_i2c_bit_set(bus, 1, 1); | |
203 | snd_i2c_bit_hw_stop(bus); | |
204 | } | |
205 | ||
206 | static void snd_i2c_bit_send(snd_i2c_bus_t *bus, int data) | |
207 | { | |
208 | snd_i2c_bit_set(bus, 0, data); | |
209 | snd_i2c_bit_set(bus, 1, data); | |
210 | snd_i2c_bit_set(bus, 0, data); | |
211 | } | |
212 | ||
213 | static int snd_i2c_bit_ack(snd_i2c_bus_t *bus) | |
214 | { | |
215 | int ack; | |
216 | ||
217 | snd_i2c_bit_set(bus, 0, 1); | |
218 | snd_i2c_bit_set(bus, 1, 1); | |
219 | snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */ | |
220 | ack = snd_i2c_bit_data(bus, 1); | |
221 | snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */ | |
222 | snd_i2c_bit_set(bus, 0, 1); | |
223 | return ack ? -EIO : 0; | |
224 | } | |
225 | ||
226 | static int snd_i2c_bit_sendbyte(snd_i2c_bus_t *bus, unsigned char data) | |
227 | { | |
228 | int i, err; | |
229 | ||
230 | for (i = 7; i >= 0; i--) | |
231 | snd_i2c_bit_send(bus, !!(data & (1 << i))); | |
232 | if ((err = snd_i2c_bit_ack(bus)) < 0) | |
233 | return err; | |
234 | return 0; | |
235 | } | |
236 | ||
237 | static int snd_i2c_bit_readbyte(snd_i2c_bus_t *bus, int last) | |
238 | { | |
239 | int i; | |
240 | unsigned char data = 0; | |
241 | ||
242 | snd_i2c_bit_set(bus, 0, 1); | |
243 | snd_i2c_bit_direction(bus, 1, 0); /* SCL - wr, SDA - rd */ | |
244 | for (i = 7; i >= 0; i--) { | |
245 | snd_i2c_bit_set(bus, 1, 1); | |
246 | if (snd_i2c_bit_data(bus, 0)) | |
247 | data |= (1 << i); | |
248 | snd_i2c_bit_set(bus, 0, 1); | |
249 | } | |
250 | snd_i2c_bit_direction(bus, 1, 1); /* SCL - wr, SDA - wr */ | |
251 | snd_i2c_bit_send(bus, !!last); | |
252 | return data; | |
253 | } | |
254 | ||
255 | static int snd_i2c_bit_sendbytes(snd_i2c_device_t *device, unsigned char *bytes, int count) | |
256 | { | |
257 | snd_i2c_bus_t *bus = device->bus; | |
258 | int err, res = 0; | |
259 | ||
260 | if (device->flags & SND_I2C_DEVICE_ADDRTEN) | |
261 | return -EIO; /* not yet implemented */ | |
262 | snd_i2c_bit_start(bus); | |
263 | if ((err = snd_i2c_bit_sendbyte(bus, device->addr << 1)) < 0) { | |
264 | snd_i2c_bit_hw_stop(bus); | |
265 | return err; | |
266 | } | |
267 | while (count-- > 0) { | |
268 | if ((err = snd_i2c_bit_sendbyte(bus, *bytes++)) < 0) { | |
269 | snd_i2c_bit_hw_stop(bus); | |
270 | return err; | |
271 | } | |
272 | res++; | |
273 | } | |
274 | snd_i2c_bit_stop(bus); | |
275 | return res; | |
276 | } | |
277 | ||
278 | static int snd_i2c_bit_readbytes(snd_i2c_device_t *device, unsigned char *bytes, int count) | |
279 | { | |
280 | snd_i2c_bus_t *bus = device->bus; | |
281 | int err, res = 0; | |
282 | ||
283 | if (device->flags & SND_I2C_DEVICE_ADDRTEN) | |
284 | return -EIO; /* not yet implemented */ | |
285 | snd_i2c_bit_start(bus); | |
286 | if ((err = snd_i2c_bit_sendbyte(bus, (device->addr << 1) | 1)) < 0) { | |
287 | snd_i2c_bit_hw_stop(bus); | |
288 | return err; | |
289 | } | |
290 | while (count-- > 0) { | |
291 | if ((err = snd_i2c_bit_readbyte(bus, count == 0)) < 0) { | |
292 | snd_i2c_bit_hw_stop(bus); | |
293 | return err; | |
294 | } | |
295 | *bytes++ = (unsigned char)err; | |
296 | res++; | |
297 | } | |
298 | snd_i2c_bit_stop(bus); | |
299 | return res; | |
300 | } | |
301 | ||
302 | static int snd_i2c_bit_probeaddr(snd_i2c_bus_t *bus, unsigned short addr) | |
303 | { | |
304 | int err; | |
305 | ||
306 | if (addr & 0x8000) /* 10-bit address */ | |
307 | return -EIO; /* not yet implemented */ | |
308 | if (addr & 0x7f80) /* invalid address */ | |
309 | return -EINVAL; | |
310 | snd_i2c_bit_start(bus); | |
311 | err = snd_i2c_bit_sendbyte(bus, addr << 1); | |
312 | snd_i2c_bit_stop(bus); | |
313 | return err; | |
314 | } | |
315 | ||
316 | EXPORT_SYMBOL(snd_i2c_bus_create); | |
317 | EXPORT_SYMBOL(snd_i2c_device_create); | |
318 | EXPORT_SYMBOL(snd_i2c_device_free); | |
319 | EXPORT_SYMBOL(snd_i2c_sendbytes); | |
320 | EXPORT_SYMBOL(snd_i2c_readbytes); | |
321 | EXPORT_SYMBOL(snd_i2c_probeaddr); | |
322 | ||
323 | static int __init alsa_i2c_init(void) | |
324 | { | |
325 | return 0; | |
326 | } | |
327 | ||
328 | static void __exit alsa_i2c_exit(void) | |
329 | { | |
330 | } | |
331 | ||
332 | module_init(alsa_i2c_init) | |
333 | module_exit(alsa_i2c_exit) |