27dcfc69cd801ac6928f7a3e55818a97466b2469
[linux-2.6.git] / drivers / media / video / au0828 / au0828-i2c.c
1 /*
2  *  Driver for the Auvitek AU0828 USB bridge
3  *
4  *  Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
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, AU0828_I2C_STATUS_201) &
43                 AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
44 }
45
46 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
47 {
48         struct au0828_dev *dev = i2c_adap->algo_data;
49         return au0828_read(dev, AU0828_I2C_STATUS_201) &
50                 AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
51 }
52
53 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
54 {
55         int count;
56
57         for (count = 0; count < I2C_WAIT_RETRY; count++) {
58                 if (!i2c_slave_did_read_ack(i2c_adap))
59                         break;
60                 udelay(I2C_WAIT_DELAY);
61         }
62
63         if (I2C_WAIT_RETRY == count)
64                 return 0;
65
66         return 1;
67 }
68
69 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
70 {
71         struct au0828_dev *dev = i2c_adap->algo_data;
72         return au0828_read(dev, AU0828_I2C_STATUS_201) &
73                 AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
74 }
75
76 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
77 {
78         int count;
79
80         for (count = 0; count < I2C_WAIT_RETRY; count++) {
81                 if (!i2c_is_read_busy(i2c_adap))
82                         break;
83                 udelay(I2C_WAIT_DELAY);
84         }
85
86         if (I2C_WAIT_RETRY == count)
87                 return 0;
88
89         return 1;
90 }
91
92 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
93 {
94         struct au0828_dev *dev = i2c_adap->algo_data;
95         return au0828_read(dev, AU0828_I2C_STATUS_201) &
96                 AU0828_I2C_STATUS_WRITE_DONE ? 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, AU0828_I2C_STATUS_201) &
119                 AU0828_I2C_STATUS_BUSY ? 1 : 0;
120 }
121
122 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
123 {
124         int count;
125
126         for (count = 0; count < I2C_WAIT_RETRY; count++) {
127                 if (!i2c_is_busy(i2c_adap))
128                         break;
129                 udelay(I2C_WAIT_DELAY);
130         }
131
132         if (I2C_WAIT_RETRY == count)
133                 return 0;
134
135         return 1;
136 }
137
138 /* FIXME: Implement join handling correctly */
139 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
140         const struct i2c_msg *msg, int joined_rlen)
141 {
142         int i, strobe = 0;
143         struct au0828_dev *dev = i2c_adap->algo_data;
144
145         dprintk(4, "%s()\n", __func__);
146
147         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
148
149         /* FIXME: There is a problem with i2c communications with xc5000 that
150            requires us to slow down the i2c clock until we have a better
151            strategy (such as using the secondary i2c bus to do firmware
152            loading */
153         if ((msg->addr << 1) == 0xc2)
154                 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
155                              AU0828_I2C_CLK_30KHZ);
156         else
157                 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
158                              AU0828_I2C_CLK_250KHZ);
159
160         /* Hardware needs 8 bit addresses */
161         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
162
163         dprintk(4, "SEND: %02x\n", msg->addr);
164
165         /* Deal with i2c_scan */
166         if (msg->len == 0) {
167                 /* The analog tuner detection code makes use of the SMBUS_QUICK
168                    message (which involves a zero length i2c write).  To avoid
169                    checking the status register when we didn't strobe out any
170                    actual bytes to the bus, just do a read check.  This is
171                    consistent with how I saw i2c device checking done in the
172                    USB trace of the Windows driver */
173                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
174                              AU0828_I2C_TRIGGER_READ);
175
176                 if (!i2c_wait_done(i2c_adap))
177                         return -EIO;
178
179                 if (i2c_wait_read_ack(i2c_adap))
180                         return -EIO;
181
182                 return 0;
183         }
184
185         for (i = 0; i < msg->len;) {
186
187                 dprintk(4, " %02x\n", msg->buf[i]);
188
189                 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
190
191                 strobe++;
192                 i++;
193
194                 if ((strobe >= 4) || (i >= msg->len)) {
195
196                         /* Strobe the byte into the bus */
197                         if (i < msg->len)
198                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
199                                              AU0828_I2C_TRIGGER_WRITE |
200                                              AU0828_I2C_TRIGGER_HOLD);
201                         else
202                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
203                                              AU0828_I2C_TRIGGER_WRITE);
204
205                         /* Reset strobe trigger */
206                         strobe = 0;
207
208                         if (!i2c_wait_write_done(i2c_adap))
209                                 return -EIO;
210
211                 }
212
213         }
214         if (!i2c_wait_done(i2c_adap))
215                 return -EIO;
216
217         dprintk(4, "\n");
218
219         return msg->len;
220 }
221
222 /* FIXME: Implement join handling correctly */
223 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
224         const struct i2c_msg *msg, int joined)
225 {
226         struct au0828_dev *dev = i2c_adap->algo_data;
227         int i;
228
229         dprintk(4, "%s()\n", __func__);
230
231         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
232
233         /* FIXME: There is a problem with i2c communications with xc5000 that
234            requires us to slow down the i2c clock until we have a better
235            strategy (such as using the secondary i2c bus to do firmware
236            loading */
237         if ((msg->addr << 1) == 0xc2)
238                 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
239                              AU0828_I2C_CLK_30KHZ);
240         else
241                 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
242                              AU0828_I2C_CLK_250KHZ);
243
244         /* Hardware needs 8 bit addresses */
245         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
246
247         dprintk(4, " RECV:\n");
248
249         /* Deal with i2c_scan */
250         if (msg->len == 0) {
251                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
252                              AU0828_I2C_TRIGGER_READ);
253
254                 if (i2c_wait_read_ack(i2c_adap))
255                         return -EIO;
256                 return 0;
257         }
258
259         for (i = 0; i < msg->len;) {
260
261                 i++;
262
263                 if (i < msg->len)
264                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
265                                      AU0828_I2C_TRIGGER_READ |
266                                      AU0828_I2C_TRIGGER_HOLD);
267                 else
268                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
269                                      AU0828_I2C_TRIGGER_READ);
270
271                 if (!i2c_wait_read_done(i2c_adap))
272                         return -EIO;
273
274                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
275                         0xff;
276
277                 dprintk(4, " %02x\n", msg->buf[i-1]);
278         }
279         if (!i2c_wait_done(i2c_adap))
280                 return -EIO;
281
282         dprintk(4, "\n");
283
284         return msg->len;
285 }
286
287 static int i2c_xfer(struct i2c_adapter *i2c_adap,
288                     struct i2c_msg *msgs, int num)
289 {
290         int i, retval = 0;
291
292         dprintk(4, "%s(num = %d)\n", __func__, num);
293
294         for (i = 0; i < num; i++) {
295                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
296                         __func__, num, msgs[i].addr, msgs[i].len);
297                 if (msgs[i].flags & I2C_M_RD) {
298                         /* read */
299                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
300                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
301                            msgs[i].addr == msgs[i + 1].addr) {
302                         /* write then read from same address */
303                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
304                                                msgs[i + 1].len);
305                         if (retval < 0)
306                                 goto err;
307                         i++;
308                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
309                 } else {
310                         /* write */
311                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
312                 }
313                 if (retval < 0)
314                         goto err;
315         }
316         return num;
317
318 err:
319         return retval;
320 }
321
322 static u32 au0828_functionality(struct i2c_adapter *adap)
323 {
324         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
325 }
326
327 static struct i2c_algorithm au0828_i2c_algo_template = {
328         .master_xfer    = i2c_xfer,
329         .functionality  = au0828_functionality,
330 };
331
332 /* ----------------------------------------------------------------------- */
333
334 static struct i2c_adapter au0828_i2c_adap_template = {
335         .name              = DRIVER_NAME,
336         .owner             = THIS_MODULE,
337         .id                = I2C_HW_B_AU0828,
338         .algo              = &au0828_i2c_algo_template,
339 };
340
341 static struct i2c_client au0828_i2c_client_template = {
342         .name   = "au0828 internal",
343 };
344
345 static char *i2c_devs[128] = {
346         [0x8e >> 1] = "au8522",
347         [0xa0 >> 1] = "eeprom",
348         [0xc2 >> 1] = "tuner/xc5000",
349 };
350
351 static void do_i2c_scan(char *name, struct i2c_client *c)
352 {
353         unsigned char buf;
354         int i, rc;
355
356         for (i = 0; i < 128; i++) {
357                 c->addr = i;
358                 rc = i2c_master_recv(c, &buf, 0);
359                 if (rc < 0)
360                         continue;
361                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
362                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
363         }
364 }
365
366 /* init + register i2c algo-bit adapter */
367 int au0828_i2c_register(struct au0828_dev *dev)
368 {
369         dprintk(1, "%s()\n", __func__);
370
371         memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
372                sizeof(dev->i2c_adap));
373         memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
374                sizeof(dev->i2c_algo));
375         memcpy(&dev->i2c_client, &au0828_i2c_client_template,
376                sizeof(dev->i2c_client));
377
378         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
379
380         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
381                 sizeof(dev->i2c_adap.name));
382
383         dev->i2c_adap.algo = &dev->i2c_algo;
384         dev->i2c_adap.algo_data = dev;
385         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
386         i2c_add_adapter(&dev->i2c_adap);
387
388         dev->i2c_client.adapter = &dev->i2c_adap;
389
390         if (0 == dev->i2c_rc) {
391                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
392                 if (i2c_scan)
393                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
394         } else
395                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
396
397         return dev->i2c_rc;
398 }
399
400 int au0828_i2c_unregister(struct au0828_dev *dev)
401 {
402         i2c_del_adapter(&dev->i2c_adap);
403         return 0;
404 }
405