Merge git://git.infradead.org/mtd-2.6
[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 unsigned int i2c_debug;
33 module_param(i2c_debug, int, 0444);
34 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
35
36 unsigned int i2c_scan;
37 module_param(i2c_scan, int, 0444);
38 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
39
40 #define I2C_WAIT_DELAY 512
41 #define I2C_WAIT_RETRY 64
42
43 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
44 {
45         struct au0828_dev *dev = i2c_adap->algo_data;
46         return au0828_read(dev, REG_201) & 0x08 ? 0 : 1;
47 }
48
49 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
50 {
51         struct au0828_dev *dev = i2c_adap->algo_data;
52         return au0828_read(dev, REG_201) & 0x02 ? 0 : 1;
53 }
54
55 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
56 {
57         int count;
58
59         for (count = 0; count < I2C_WAIT_RETRY; count++) {
60                 if (!i2c_slave_did_read_ack(i2c_adap))
61                         break;
62                 udelay(I2C_WAIT_DELAY);
63         }
64
65         if (I2C_WAIT_RETRY == count)
66                 return 0;
67
68         return 1;
69 }
70
71 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
72 {
73         struct au0828_dev *dev = i2c_adap->algo_data;
74         return au0828_read(dev, REG_201) & 0x01 ? 0 : 1;
75 }
76
77 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
78 {
79         int count;
80
81         for (count = 0; count < I2C_WAIT_RETRY; count++) {
82                 if (!i2c_is_read_busy(i2c_adap))
83                         break;
84                 udelay(I2C_WAIT_DELAY);
85         }
86
87         if (I2C_WAIT_RETRY == count)
88                 return 0;
89
90         return 1;
91 }
92
93 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
94 {
95         struct au0828_dev *dev = i2c_adap->algo_data;
96         return au0828_read(dev, REG_201) & 0x04 ? 1 : 0;
97 }
98
99 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
100 {
101         int count;
102
103         for (count = 0; count < I2C_WAIT_RETRY; count++) {
104                 if (i2c_is_write_done(i2c_adap))
105                         break;
106                 udelay(I2C_WAIT_DELAY);
107         }
108
109         if (I2C_WAIT_RETRY == count)
110                 return 0;
111
112         return 1;
113 }
114
115 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
116 {
117         struct au0828_dev *dev = i2c_adap->algo_data;
118         return au0828_read(dev, REG_201) & 0x10 ? 1 : 0;
119 }
120
121 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
122 {
123         int count;
124
125         for (count = 0; count < I2C_WAIT_RETRY; count++) {
126                 if (!i2c_is_busy(i2c_adap))
127                         break;
128                 udelay(I2C_WAIT_DELAY);
129         }
130
131         if (I2C_WAIT_RETRY == count)
132                 return 0;
133
134         return 1;
135 }
136
137 /* FIXME: Implement join handling correctly */
138 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
139         const struct i2c_msg *msg, int joined_rlen)
140 {
141         int i, strobe = 0;
142         struct au0828_dev *dev = i2c_adap->algo_data;
143
144         dprintk(4, "%s()\n", __func__);
145
146         au0828_write(dev, REG_2FF, 0x01);
147         au0828_write(dev, REG_202, 0x07);
148
149         /* Hardware needs 8 bit addresses */
150         au0828_write(dev, REG_203, msg->addr << 1);
151
152         dprintk(4, "SEND: %02x\n", msg->addr);
153
154         for (i = 0; i < msg->len;) {
155
156                 dprintk(4, " %02x\n", msg->buf[i]);
157
158                 au0828_write(dev, REG_205, msg->buf[i]);
159
160                 strobe++;
161                 i++;
162
163                 if ((strobe >= 4) || (i >= msg->len)) {
164
165                         /* Strobe the byte into the bus */
166                         if (i < msg->len)
167                                 au0828_write(dev, REG_200, 0x41);
168                         else
169                                 au0828_write(dev, REG_200, 0x01);
170
171                         /* Reset strobe trigger */
172                         strobe = 0;
173
174                         if (!i2c_wait_write_done(i2c_adap))
175                                 return -EIO;
176
177                 }
178
179         }
180         if (!i2c_wait_done(i2c_adap))
181                 return -EIO;
182
183         dprintk(4, "\n");
184
185         return msg->len;
186 }
187
188 /* FIXME: Implement join handling correctly */
189 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
190         const struct i2c_msg *msg, int joined)
191 {
192         struct au0828_dev *dev = i2c_adap->algo_data;
193         int i;
194
195         dprintk(4, "%s()\n", __func__);
196
197         au0828_write(dev, REG_2FF, 0x01);
198         au0828_write(dev, REG_202, 0x07);
199
200         /* Hardware needs 8 bit addresses */
201         au0828_write(dev, REG_203, msg->addr << 1);
202
203         dprintk(4, " RECV:\n");
204
205         /* Deal with i2c_scan */
206         if (msg->len == 0) {
207                 au0828_write(dev, REG_200, 0x20);
208                 if (i2c_wait_read_ack(i2c_adap))
209                         return -EIO;
210                 return 0;
211         }
212
213         for (i = 0; i < msg->len;) {
214
215                 i++;
216
217                 if (i < msg->len)
218                         au0828_write(dev, REG_200, 0x60);
219                 else
220                         au0828_write(dev, REG_200, 0x20);
221
222                 if (!i2c_wait_read_done(i2c_adap))
223                         return -EIO;
224
225                 msg->buf[i-1] = au0828_read(dev, REG_209) & 0xff;
226
227                 dprintk(4, " %02x\n", msg->buf[i-1]);
228         }
229         if (!i2c_wait_done(i2c_adap))
230                 return -EIO;
231
232         dprintk(4, "\n");
233
234         return msg->len;
235 }
236
237 static int i2c_xfer(struct i2c_adapter *i2c_adap,
238                     struct i2c_msg *msgs, int num)
239 {
240         int i, retval = 0;
241
242         dprintk(4, "%s(num = %d)\n", __func__, num);
243
244         for (i = 0; i < num; i++) {
245                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
246                         __func__, num, msgs[i].addr, msgs[i].len);
247                 if (msgs[i].flags & I2C_M_RD) {
248                         /* read */
249                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
250                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
251                            msgs[i].addr == msgs[i + 1].addr) {
252                         /* write then read from same address */
253                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
254                                                msgs[i + 1].len);
255                         if (retval < 0)
256                                 goto err;
257                         i++;
258                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
259                 } else {
260                         /* write */
261                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
262                 }
263                 if (retval < 0)
264                         goto err;
265         }
266         return num;
267
268 err:
269         return retval;
270 }
271
272 static int attach_inform(struct i2c_client *client)
273 {
274         dprintk(1, "%s i2c attach [addr=0x%x,client=%s]\n",
275                 client->driver->driver.name, client->addr, client->name);
276
277         if (!client->driver->command)
278                 return 0;
279
280         return 0;
281 }
282
283 static int detach_inform(struct i2c_client *client)
284 {
285         dprintk(1, "i2c detach [client=%s]\n", client->name);
286
287         return 0;
288 }
289
290 void au0828_call_i2c_clients(struct au0828_dev *dev,
291                               unsigned int cmd, void *arg)
292 {
293         if (dev->i2c_rc != 0)
294                 return;
295
296         i2c_clients_command(&dev->i2c_adap, cmd, arg);
297 }
298
299 static u32 au0828_functionality(struct i2c_adapter *adap)
300 {
301         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
302 }
303
304 static struct i2c_algorithm au0828_i2c_algo_template = {
305         .master_xfer    = i2c_xfer,
306         .functionality  = au0828_functionality,
307 };
308
309 /* ----------------------------------------------------------------------- */
310
311 static struct i2c_adapter au0828_i2c_adap_template = {
312         .name              = DRIVER_NAME,
313         .owner             = THIS_MODULE,
314         .id                = I2C_HW_B_AU0828,
315         .algo              = &au0828_i2c_algo_template,
316         .class             = I2C_CLASS_TV_ANALOG,
317         .client_register   = attach_inform,
318         .client_unregister = detach_inform,
319 };
320
321 static struct i2c_client au0828_i2c_client_template = {
322         .name   = "au0828 internal",
323 };
324
325 static char *i2c_devs[128] = {
326         [0x8e >> 1] = "au8522",
327         [0xa0 >> 1] = "eeprom",
328         [0xc2 >> 1] = "tuner/xc5000",
329 };
330
331 static void do_i2c_scan(char *name, struct i2c_client *c)
332 {
333         unsigned char buf;
334         int i, rc;
335
336         for (i = 0; i < 128; i++) {
337                 c->addr = i;
338                 rc = i2c_master_recv(c, &buf, 0);
339                 if (rc < 0)
340                         continue;
341                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
342                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
343         }
344 }
345
346 /* init + register i2c algo-bit adapter */
347 int au0828_i2c_register(struct au0828_dev *dev)
348 {
349         dprintk(1, "%s()\n", __func__);
350
351         memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
352                sizeof(dev->i2c_adap));
353         memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
354                sizeof(dev->i2c_algo));
355         memcpy(&dev->i2c_client, &au0828_i2c_client_template,
356                sizeof(dev->i2c_client));
357
358         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
359
360         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
361                 sizeof(dev->i2c_adap.name));
362
363         dev->i2c_algo.data = dev;
364         dev->i2c_adap.algo_data = dev;
365         i2c_set_adapdata(&dev->i2c_adap, dev);
366         i2c_add_adapter(&dev->i2c_adap);
367
368         dev->i2c_client.adapter = &dev->i2c_adap;
369
370         if (0 == dev->i2c_rc) {
371                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
372                 if (i2c_scan)
373                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
374         } else
375                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
376
377         return dev->i2c_rc;
378 }
379
380 int au0828_i2c_unregister(struct au0828_dev *dev)
381 {
382         i2c_del_adapter(&dev->i2c_adap);
383         return 0;
384 }
385