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[linux-2.6] / drivers / media / video / au0828 / au0828-i2c.c
1 /*
2  *  Driver for the Auvitek AU0828 USB bridge
3  *
4  *  Copyright (c) 2008 Steven Toth <stoth@hauppauge.com>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *
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., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/init.h>
25 #include <linux/delay.h>
26 #include <linux/io.h>
27
28 #include "au0828.h"
29
30 #include <media/v4l2-common.h>
31
32 static int i2c_scan;
33 module_param(i2c_scan, int, 0444);
34 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
35
36 #define I2C_WAIT_DELAY 512
37 #define I2C_WAIT_RETRY 64
38
39 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
40 {
41         struct au0828_dev *dev = i2c_adap->algo_data;
42         return au0828_read(dev, REG_201) & 0x08 ? 0 : 1;
43 }
44
45 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
46 {
47         struct au0828_dev *dev = i2c_adap->algo_data;
48         return au0828_read(dev, REG_201) & 0x02 ? 0 : 1;
49 }
50
51 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
52 {
53         int count;
54
55         for (count = 0; count < I2C_WAIT_RETRY; count++) {
56                 if (!i2c_slave_did_read_ack(i2c_adap))
57                         break;
58                 udelay(I2C_WAIT_DELAY);
59         }
60
61         if (I2C_WAIT_RETRY == count)
62                 return 0;
63
64         return 1;
65 }
66
67 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
68 {
69         struct au0828_dev *dev = i2c_adap->algo_data;
70         return au0828_read(dev, REG_201) & 0x01 ? 0 : 1;
71 }
72
73 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
74 {
75         int count;
76
77         for (count = 0; count < I2C_WAIT_RETRY; count++) {
78                 if (!i2c_is_read_busy(i2c_adap))
79                         break;
80                 udelay(I2C_WAIT_DELAY);
81         }
82
83         if (I2C_WAIT_RETRY == count)
84                 return 0;
85
86         return 1;
87 }
88
89 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
90 {
91         struct au0828_dev *dev = i2c_adap->algo_data;
92         return au0828_read(dev, REG_201) & 0x04 ? 1 : 0;
93 }
94
95 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
96 {
97         int count;
98
99         for (count = 0; count < I2C_WAIT_RETRY; count++) {
100                 if (i2c_is_write_done(i2c_adap))
101                         break;
102                 udelay(I2C_WAIT_DELAY);
103         }
104
105         if (I2C_WAIT_RETRY == count)
106                 return 0;
107
108         return 1;
109 }
110
111 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
112 {
113         struct au0828_dev *dev = i2c_adap->algo_data;
114         return au0828_read(dev, REG_201) & 0x10 ? 1 : 0;
115 }
116
117 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
118 {
119         int count;
120
121         for (count = 0; count < I2C_WAIT_RETRY; count++) {
122                 if (!i2c_is_busy(i2c_adap))
123                         break;
124                 udelay(I2C_WAIT_DELAY);
125         }
126
127         if (I2C_WAIT_RETRY == count)
128                 return 0;
129
130         return 1;
131 }
132
133 /* FIXME: Implement join handling correctly */
134 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
135         const struct i2c_msg *msg, int joined_rlen)
136 {
137         int i, strobe = 0;
138         struct au0828_dev *dev = i2c_adap->algo_data;
139
140         dprintk(4, "%s()\n", __func__);
141
142         au0828_write(dev, REG_2FF, 0x01);
143         au0828_write(dev, REG_202, 0x07);
144
145         /* Hardware needs 8 bit addresses */
146         au0828_write(dev, REG_203, msg->addr << 1);
147
148         dprintk(4, "SEND: %02x\n", msg->addr);
149
150         for (i = 0; i < msg->len;) {
151
152                 dprintk(4, " %02x\n", msg->buf[i]);
153
154                 au0828_write(dev, REG_205, msg->buf[i]);
155
156                 strobe++;
157                 i++;
158
159                 if ((strobe >= 4) || (i >= msg->len)) {
160
161                         /* Strobe the byte into the bus */
162                         if (i < msg->len)
163                                 au0828_write(dev, REG_200, 0x41);
164                         else
165                                 au0828_write(dev, REG_200, 0x01);
166
167                         /* Reset strobe trigger */
168                         strobe = 0;
169
170                         if (!i2c_wait_write_done(i2c_adap))
171                                 return -EIO;
172
173                 }
174
175         }
176         if (!i2c_wait_done(i2c_adap))
177                 return -EIO;
178
179         dprintk(4, "\n");
180
181         return msg->len;
182 }
183
184 /* FIXME: Implement join handling correctly */
185 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
186         const struct i2c_msg *msg, int joined)
187 {
188         struct au0828_dev *dev = i2c_adap->algo_data;
189         int i;
190
191         dprintk(4, "%s()\n", __func__);
192
193         au0828_write(dev, REG_2FF, 0x01);
194         au0828_write(dev, REG_202, 0x07);
195
196         /* Hardware needs 8 bit addresses */
197         au0828_write(dev, REG_203, msg->addr << 1);
198
199         dprintk(4, " RECV:\n");
200
201         /* Deal with i2c_scan */
202         if (msg->len == 0) {
203                 au0828_write(dev, REG_200, 0x20);
204                 if (i2c_wait_read_ack(i2c_adap))
205                         return -EIO;
206                 return 0;
207         }
208
209         for (i = 0; i < msg->len;) {
210
211                 i++;
212
213                 if (i < msg->len)
214                         au0828_write(dev, REG_200, 0x60);
215                 else
216                         au0828_write(dev, REG_200, 0x20);
217
218                 if (!i2c_wait_read_done(i2c_adap))
219                         return -EIO;
220
221                 msg->buf[i-1] = au0828_read(dev, REG_209) & 0xff;
222
223                 dprintk(4, " %02x\n", msg->buf[i-1]);
224         }
225         if (!i2c_wait_done(i2c_adap))
226                 return -EIO;
227
228         dprintk(4, "\n");
229
230         return msg->len;
231 }
232
233 static int i2c_xfer(struct i2c_adapter *i2c_adap,
234                     struct i2c_msg *msgs, int num)
235 {
236         int i, retval = 0;
237
238         dprintk(4, "%s(num = %d)\n", __func__, num);
239
240         for (i = 0; i < num; i++) {
241                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
242                         __func__, num, msgs[i].addr, msgs[i].len);
243                 if (msgs[i].flags & I2C_M_RD) {
244                         /* read */
245                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
246                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
247                            msgs[i].addr == msgs[i + 1].addr) {
248                         /* write then read from same address */
249                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
250                                                msgs[i + 1].len);
251                         if (retval < 0)
252                                 goto err;
253                         i++;
254                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
255                 } else {
256                         /* write */
257                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
258                 }
259                 if (retval < 0)
260                         goto err;
261         }
262         return num;
263
264 err:
265         return retval;
266 }
267
268 static int attach_inform(struct i2c_client *client)
269 {
270         dprintk(1, "%s i2c attach [addr=0x%x,client=%s]\n",
271                 client->driver->driver.name, client->addr, client->name);
272
273         if (!client->driver->command)
274                 return 0;
275
276         return 0;
277 }
278
279 static int detach_inform(struct i2c_client *client)
280 {
281         dprintk(1, "i2c detach [client=%s]\n", client->name);
282
283         return 0;
284 }
285
286 void au0828_call_i2c_clients(struct au0828_dev *dev,
287                               unsigned int cmd, void *arg)
288 {
289         if (dev->i2c_rc != 0)
290                 return;
291
292         i2c_clients_command(&dev->i2c_adap, cmd, arg);
293 }
294
295 static u32 au0828_functionality(struct i2c_adapter *adap)
296 {
297         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
298 }
299
300 static struct i2c_algorithm au0828_i2c_algo_template = {
301         .master_xfer    = i2c_xfer,
302         .functionality  = au0828_functionality,
303 };
304
305 /* ----------------------------------------------------------------------- */
306
307 static struct i2c_adapter au0828_i2c_adap_template = {
308         .name              = DRIVER_NAME,
309         .owner             = THIS_MODULE,
310         .id                = I2C_HW_B_AU0828,
311         .algo              = &au0828_i2c_algo_template,
312         .class             = I2C_CLASS_TV_ANALOG,
313         .client_register   = attach_inform,
314         .client_unregister = detach_inform,
315 };
316
317 static struct i2c_client au0828_i2c_client_template = {
318         .name   = "au0828 internal",
319 };
320
321 static char *i2c_devs[128] = {
322         [0x8e >> 1] = "au8522",
323         [0xa0 >> 1] = "eeprom",
324         [0xc2 >> 1] = "tuner/xc5000",
325 };
326
327 static void do_i2c_scan(char *name, struct i2c_client *c)
328 {
329         unsigned char buf;
330         int i, rc;
331
332         for (i = 0; i < 128; i++) {
333                 c->addr = i;
334                 rc = i2c_master_recv(c, &buf, 0);
335                 if (rc < 0)
336                         continue;
337                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
338                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
339         }
340 }
341
342 /* init + register i2c algo-bit adapter */
343 int au0828_i2c_register(struct au0828_dev *dev)
344 {
345         dprintk(1, "%s()\n", __func__);
346
347         memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
348                sizeof(dev->i2c_adap));
349         memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
350                sizeof(dev->i2c_algo));
351         memcpy(&dev->i2c_client, &au0828_i2c_client_template,
352                sizeof(dev->i2c_client));
353
354         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
355
356         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
357                 sizeof(dev->i2c_adap.name));
358
359         dev->i2c_algo.data = dev;
360         dev->i2c_adap.algo_data = dev;
361         i2c_set_adapdata(&dev->i2c_adap, dev);
362         i2c_add_adapter(&dev->i2c_adap);
363
364         dev->i2c_client.adapter = &dev->i2c_adap;
365
366         if (0 == dev->i2c_rc) {
367                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
368                 if (i2c_scan)
369                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
370         } else
371                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
372
373         return dev->i2c_rc;
374 }
375
376 int au0828_i2c_unregister(struct au0828_dev *dev)
377 {
378         i2c_del_adapter(&dev->i2c_adap);
379         return 0;
380 }
381