V4L/DVB (12112): cx231xx: fix uninitialized variable.
[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@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         /* Set the I2C clock */
150         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
151                      dev->board.i2c_clk_divider);
152
153         /* Hardware needs 8 bit addresses */
154         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
155
156         dprintk(4, "SEND: %02x\n", msg->addr);
157
158         /* Deal with i2c_scan */
159         if (msg->len == 0) {
160                 /* The analog tuner detection code makes use of the SMBUS_QUICK
161                    message (which involves a zero length i2c write).  To avoid
162                    checking the status register when we didn't strobe out any
163                    actual bytes to the bus, just do a read check.  This is
164                    consistent with how I saw i2c device checking done in the
165                    USB trace of the Windows driver */
166                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
167                              AU0828_I2C_TRIGGER_READ);
168
169                 if (!i2c_wait_done(i2c_adap))
170                         return -EIO;
171
172                 if (i2c_wait_read_ack(i2c_adap))
173                         return -EIO;
174
175                 return 0;
176         }
177
178         for (i = 0; i < msg->len;) {
179
180                 dprintk(4, " %02x\n", msg->buf[i]);
181
182                 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
183
184                 strobe++;
185                 i++;
186
187                 if ((strobe >= 4) || (i >= msg->len)) {
188
189                         /* Strobe the byte into the bus */
190                         if (i < msg->len)
191                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
192                                              AU0828_I2C_TRIGGER_WRITE |
193                                              AU0828_I2C_TRIGGER_HOLD);
194                         else
195                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
196                                              AU0828_I2C_TRIGGER_WRITE);
197
198                         /* Reset strobe trigger */
199                         strobe = 0;
200
201                         if (!i2c_wait_write_done(i2c_adap))
202                                 return -EIO;
203
204                 }
205
206         }
207         if (!i2c_wait_done(i2c_adap))
208                 return -EIO;
209
210         dprintk(4, "\n");
211
212         return msg->len;
213 }
214
215 /* FIXME: Implement join handling correctly */
216 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
217         const struct i2c_msg *msg, int joined)
218 {
219         struct au0828_dev *dev = i2c_adap->algo_data;
220         int i;
221
222         dprintk(4, "%s()\n", __func__);
223
224         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
225
226         /* Set the I2C clock */
227         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
228                      dev->board.i2c_clk_divider);
229
230         /* Hardware needs 8 bit addresses */
231         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
232
233         dprintk(4, " RECV:\n");
234
235         /* Deal with i2c_scan */
236         if (msg->len == 0) {
237                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
238                              AU0828_I2C_TRIGGER_READ);
239
240                 if (i2c_wait_read_ack(i2c_adap))
241                         return -EIO;
242                 return 0;
243         }
244
245         for (i = 0; i < msg->len;) {
246
247                 i++;
248
249                 if (i < msg->len)
250                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
251                                      AU0828_I2C_TRIGGER_READ |
252                                      AU0828_I2C_TRIGGER_HOLD);
253                 else
254                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
255                                      AU0828_I2C_TRIGGER_READ);
256
257                 if (!i2c_wait_read_done(i2c_adap))
258                         return -EIO;
259
260                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
261                         0xff;
262
263                 dprintk(4, " %02x\n", msg->buf[i-1]);
264         }
265         if (!i2c_wait_done(i2c_adap))
266                 return -EIO;
267
268         dprintk(4, "\n");
269
270         return msg->len;
271 }
272
273 static int i2c_xfer(struct i2c_adapter *i2c_adap,
274                     struct i2c_msg *msgs, int num)
275 {
276         int i, retval = 0;
277
278         dprintk(4, "%s(num = %d)\n", __func__, num);
279
280         for (i = 0; i < num; i++) {
281                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
282                         __func__, num, msgs[i].addr, msgs[i].len);
283                 if (msgs[i].flags & I2C_M_RD) {
284                         /* read */
285                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
286                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
287                            msgs[i].addr == msgs[i + 1].addr) {
288                         /* write then read from same address */
289                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
290                                                msgs[i + 1].len);
291                         if (retval < 0)
292                                 goto err;
293                         i++;
294                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
295                 } else {
296                         /* write */
297                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
298                 }
299                 if (retval < 0)
300                         goto err;
301         }
302         return num;
303
304 err:
305         return retval;
306 }
307
308 static u32 au0828_functionality(struct i2c_adapter *adap)
309 {
310         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
311 }
312
313 static struct i2c_algorithm au0828_i2c_algo_template = {
314         .master_xfer    = i2c_xfer,
315         .functionality  = au0828_functionality,
316 };
317
318 /* ----------------------------------------------------------------------- */
319
320 static struct i2c_adapter au0828_i2c_adap_template = {
321         .name              = DRIVER_NAME,
322         .owner             = THIS_MODULE,
323         .id                = I2C_HW_B_AU0828,
324         .algo              = &au0828_i2c_algo_template,
325 };
326
327 static struct i2c_client au0828_i2c_client_template = {
328         .name   = "au0828 internal",
329 };
330
331 static char *i2c_devs[128] = {
332         [0x8e >> 1] = "au8522",
333         [0xa0 >> 1] = "eeprom",
334         [0xc2 >> 1] = "tuner/xc5000",
335 };
336
337 static void do_i2c_scan(char *name, struct i2c_client *c)
338 {
339         unsigned char buf;
340         int i, rc;
341
342         for (i = 0; i < 128; i++) {
343                 c->addr = i;
344                 rc = i2c_master_recv(c, &buf, 0);
345                 if (rc < 0)
346                         continue;
347                 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
348                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
349         }
350 }
351
352 /* init + register i2c algo-bit adapter */
353 int au0828_i2c_register(struct au0828_dev *dev)
354 {
355         dprintk(1, "%s()\n", __func__);
356
357         memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
358                sizeof(dev->i2c_adap));
359         memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
360                sizeof(dev->i2c_algo));
361         memcpy(&dev->i2c_client, &au0828_i2c_client_template,
362                sizeof(dev->i2c_client));
363
364         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
365
366         strlcpy(dev->i2c_adap.name, DRIVER_NAME,
367                 sizeof(dev->i2c_adap.name));
368
369         dev->i2c_adap.algo = &dev->i2c_algo;
370         dev->i2c_adap.algo_data = dev;
371         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
372         i2c_add_adapter(&dev->i2c_adap);
373
374         dev->i2c_client.adapter = &dev->i2c_adap;
375
376         if (0 == dev->i2c_rc) {
377                 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
378                 if (i2c_scan)
379                         do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
380         } else
381                 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);
382
383         return dev->i2c_rc;
384 }
385
386 int au0828_i2c_unregister(struct au0828_dev *dev)
387 {
388         i2c_del_adapter(&dev->i2c_adap);
389         return 0;
390 }
391