]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | #include <linux/version.h> |
2 | #include <media/saa7146_vv.h> | |
3 | ||
4 | static u32 saa7146_i2c_func(struct i2c_adapter *adapter) | |
5 | { | |
6 | //fm DEB_I2C(("'%s'.\n", adapter->name)); | |
7 | ||
8 | return I2C_FUNC_I2C | |
9 | | I2C_FUNC_SMBUS_QUICK | |
10 | | I2C_FUNC_SMBUS_READ_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE | |
11 | | I2C_FUNC_SMBUS_READ_BYTE_DATA | I2C_FUNC_SMBUS_WRITE_BYTE_DATA; | |
12 | } | |
13 | ||
14 | /* this function returns the status-register of our i2c-device */ | |
15 | static inline u32 saa7146_i2c_status(struct saa7146_dev *dev) | |
16 | { | |
17 | u32 iicsta = saa7146_read(dev, I2C_STATUS); | |
18 | /* | |
19 | DEB_I2C(("status: 0x%08x\n",iicsta)); | |
20 | */ | |
21 | return iicsta; | |
22 | } | |
23 | ||
24 | /* this function runs through the i2c-messages and prepares the data to be | |
25 | sent through the saa7146. have a look at the specifications p. 122 ff | |
26 | to understand this. it returns the number of u32s to send, or -1 | |
27 | in case of an error. */ | |
28 | static int saa7146_i2c_msg_prepare(const struct i2c_msg *m, int num, u32 *op) | |
29 | { | |
30 | int h1, h2; | |
31 | int i, j, addr; | |
32 | int mem = 0, op_count = 0; | |
33 | ||
34 | /* first determine size of needed memory */ | |
35 | for(i = 0; i < num; i++) { | |
36 | mem += m[i].len + 1; | |
37 | } | |
38 | ||
39 | /* worst case: we need one u32 for three bytes to be send | |
40 | plus one extra byte to address the device */ | |
41 | mem = 1 + ((mem-1) / 3); | |
42 | ||
43 | /* we assume that op points to a memory of at least SAA7146_I2C_MEM bytes | |
44 | size. if we exceed this limit... */ | |
45 | if ( (4*mem) > SAA7146_I2C_MEM ) { | |
46 | //fm DEB_I2C(("cannot prepare i2c-message.\n")); | |
47 | return -ENOMEM; | |
48 | } | |
49 | ||
50 | /* be careful: clear out the i2c-mem first */ | |
51 | memset(op,0,sizeof(u32)*mem); | |
52 | ||
53 | /* loop through all messages */ | |
54 | for(i = 0; i < num; i++) { | |
55 | ||
56 | /* insert the address of the i2c-slave. | |
57 | note: we get 7 bit i2c-addresses, | |
58 | so we have to perform a translation */ | |
59 | addr = (m[i].addr*2) + ( (0 != (m[i].flags & I2C_M_RD)) ? 1 : 0); | |
60 | h1 = op_count/3; h2 = op_count%3; | |
61 | op[h1] |= ( (u8)addr << ((3-h2)*8)); | |
62 | op[h1] |= (SAA7146_I2C_START << ((3-h2)*2)); | |
63 | op_count++; | |
64 | ||
65 | /* loop through all bytes of message i */ | |
66 | for(j = 0; j < m[i].len; j++) { | |
67 | /* insert the data bytes */ | |
68 | h1 = op_count/3; h2 = op_count%3; | |
69 | op[h1] |= ( (u32)((u8)m[i].buf[j]) << ((3-h2)*8)); | |
70 | op[h1] |= ( SAA7146_I2C_CONT << ((3-h2)*2)); | |
71 | op_count++; | |
72 | } | |
73 | ||
74 | } | |
75 | ||
76 | /* have a look at the last byte inserted: | |
77 | if it was: ...CONT change it to ...STOP */ | |
78 | h1 = (op_count-1)/3; h2 = (op_count-1)%3; | |
79 | if ( SAA7146_I2C_CONT == (0x3 & (op[h1] >> ((3-h2)*2))) ) { | |
80 | op[h1] &= ~(0x2 << ((3-h2)*2)); | |
81 | op[h1] |= (SAA7146_I2C_STOP << ((3-h2)*2)); | |
82 | } | |
83 | ||
84 | /* return the number of u32s to send */ | |
85 | return mem; | |
86 | } | |
87 | ||
88 | /* this functions loops through all i2c-messages. normally, it should determine | |
89 | which bytes were read through the adapter and write them back to the corresponding | |
90 | i2c-message. but instead, we simply write back all bytes. | |
91 | fixme: this could be improved. */ | |
92 | static int saa7146_i2c_msg_cleanup(const struct i2c_msg *m, int num, u32 *op) | |
93 | { | |
94 | int i, j; | |
95 | int op_count = 0; | |
96 | ||
97 | /* loop through all messages */ | |
98 | for(i = 0; i < num; i++) { | |
99 | ||
100 | op_count++; | |
101 | ||
102 | /* loop throgh all bytes of message i */ | |
103 | for(j = 0; j < m[i].len; j++) { | |
104 | /* write back all bytes that could have been read */ | |
105 | m[i].buf[j] = (op[op_count/3] >> ((3-(op_count%3))*8)); | |
106 | op_count++; | |
107 | } | |
108 | } | |
109 | ||
110 | return 0; | |
111 | } | |
112 | ||
113 | /* this functions resets the i2c-device and returns 0 if everything was fine, otherwise -1 */ | |
114 | static int saa7146_i2c_reset(struct saa7146_dev *dev) | |
115 | { | |
116 | /* get current status */ | |
117 | u32 status = saa7146_i2c_status(dev); | |
118 | ||
119 | /* clear registers for sure */ | |
120 | saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); | |
121 | saa7146_write(dev, I2C_TRANSFER, 0); | |
122 | ||
123 | /* check if any operation is still in progress */ | |
124 | if ( 0 != ( status & SAA7146_I2C_BUSY) ) { | |
125 | ||
126 | /* yes, kill ongoing operation */ | |
127 | DEB_I2C(("busy_state detected.\n")); | |
128 | ||
129 | /* set "ABORT-OPERATION"-bit (bit 7)*/ | |
130 | saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07)); | |
131 | saa7146_write(dev, MC2, (MASK_00 | MASK_16)); | |
132 | msleep(SAA7146_I2C_DELAY); | |
133 | ||
134 | /* clear all error-bits pending; this is needed because p.123, note 1 */ | |
135 | saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); | |
136 | saa7146_write(dev, MC2, (MASK_00 | MASK_16)); | |
137 | msleep(SAA7146_I2C_DELAY); | |
138 | } | |
139 | ||
140 | /* check if any error is (still) present. (this can be necessary because p.123, note 1) */ | |
141 | status = saa7146_i2c_status(dev); | |
142 | ||
143 | if ( dev->i2c_bitrate != status ) { | |
144 | ||
145 | DEB_I2C(("error_state detected. status:0x%08x\n",status)); | |
146 | ||
147 | /* Repeat the abort operation. This seems to be necessary | |
148 | after serious protocol errors caused by e.g. the SAA7740 */ | |
149 | saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07)); | |
150 | saa7146_write(dev, MC2, (MASK_00 | MASK_16)); | |
151 | msleep(SAA7146_I2C_DELAY); | |
152 | ||
153 | /* clear all error-bits pending */ | |
154 | saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); | |
155 | saa7146_write(dev, MC2, (MASK_00 | MASK_16)); | |
156 | msleep(SAA7146_I2C_DELAY); | |
157 | ||
158 | /* the data sheet says it might be necessary to clear the status | |
159 | twice after an abort */ | |
160 | saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); | |
161 | saa7146_write(dev, MC2, (MASK_00 | MASK_16)); | |
162 | msleep(SAA7146_I2C_DELAY); | |
163 | } | |
164 | ||
165 | /* if any error is still present, a fatal error has occured ... */ | |
166 | status = saa7146_i2c_status(dev); | |
167 | if ( dev->i2c_bitrate != status ) { | |
168 | DEB_I2C(("fatal error. status:0x%08x\n",status)); | |
169 | return -1; | |
170 | } | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | /* this functions writes out the data-byte 'dword' to the i2c-device. | |
176 | it returns 0 if ok, -1 if the transfer failed, -2 if the transfer | |
177 | failed badly (e.g. address error) */ | |
178 | static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_delay) | |
179 | { | |
180 | u32 status = 0, mc2 = 0; | |
181 | int trial = 0; | |
182 | unsigned long timeout; | |
183 | ||
184 | /* write out i2c-command */ | |
185 | DEB_I2C(("before: 0x%08x (status: 0x%08x), %d\n",*dword,saa7146_read(dev, I2C_STATUS), dev->i2c_op)); | |
186 | ||
187 | if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) { | |
188 | ||
189 | saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); | |
190 | saa7146_write(dev, I2C_TRANSFER, *dword); | |
191 | ||
192 | dev->i2c_op = 1; | |
193 | SAA7146_IER_ENABLE(dev, MASK_16|MASK_17); | |
194 | saa7146_write(dev, MC2, (MASK_00 | MASK_16)); | |
195 | ||
196 | wait_event_interruptible(dev->i2c_wq, dev->i2c_op == 0); | |
197 | if (signal_pending (current)) { | |
198 | /* a signal arrived */ | |
199 | return -ERESTARTSYS; | |
200 | } | |
201 | status = saa7146_read(dev, I2C_STATUS); | |
202 | } else { | |
203 | saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); | |
204 | saa7146_write(dev, I2C_TRANSFER, *dword); | |
205 | saa7146_write(dev, MC2, (MASK_00 | MASK_16)); | |
206 | ||
207 | /* do not poll for i2c-status before upload is complete */ | |
208 | timeout = jiffies + HZ/100 + 1; /* 10ms */ | |
209 | while(1) { | |
210 | mc2 = (saa7146_read(dev, MC2) & 0x1); | |
211 | if( 0 != mc2 ) { | |
212 | break; | |
213 | } | |
214 | if (time_after(jiffies,timeout)) { | |
215 | printk(KERN_WARNING "saa7146_i2c_writeout: timed out waiting for MC2\n"); | |
216 | return -EIO; | |
217 | } | |
218 | } | |
219 | /* wait until we get a transfer done or error */ | |
220 | timeout = jiffies + HZ/100 + 1; /* 10ms */ | |
221 | while(1) { | |
222 | /** | |
223 | * first read usually delivers bogus results... | |
224 | */ | |
225 | saa7146_i2c_status(dev); | |
226 | status = saa7146_i2c_status(dev); | |
227 | if ((status & 0x3) != 1) | |
228 | break; | |
229 | if (time_after(jiffies,timeout)) { | |
230 | /* this is normal when probing the bus | |
231 | * (no answer from nonexisistant device...) | |
232 | */ | |
233 | DEB_I2C(("saa7146_i2c_writeout: timed out waiting for end of xfer\n")); | |
234 | return -EIO; | |
235 | } | |
236 | if ((++trial < 20) && short_delay) | |
237 | udelay(10); | |
238 | else | |
239 | msleep(1); | |
240 | } | |
241 | } | |
242 | ||
243 | /* give a detailed status report */ | |
244 | if ( 0 != (status & SAA7146_I2C_ERR)) { | |
245 | ||
246 | if( 0 != (status & SAA7146_I2C_SPERR) ) { | |
247 | DEB_I2C(("error due to invalid start/stop condition.\n")); | |
248 | } | |
249 | if( 0 != (status & SAA7146_I2C_DTERR) ) { | |
250 | DEB_I2C(("error in data transmission.\n")); | |
251 | } | |
252 | if( 0 != (status & SAA7146_I2C_DRERR) ) { | |
253 | DEB_I2C(("error when receiving data.\n")); | |
254 | } | |
255 | if( 0 != (status & SAA7146_I2C_AL) ) { | |
256 | DEB_I2C(("error because arbitration lost.\n")); | |
257 | } | |
258 | ||
259 | /* we handle address-errors here */ | |
260 | if( 0 != (status & SAA7146_I2C_APERR) ) { | |
261 | DEB_I2C(("error in address phase.\n")); | |
262 | return -EREMOTEIO; | |
263 | } | |
264 | ||
265 | return -EIO; | |
266 | } | |
267 | ||
268 | /* read back data, just in case we were reading ... */ | |
269 | *dword = saa7146_read(dev, I2C_TRANSFER); | |
270 | ||
271 | DEB_I2C(("after: 0x%08x\n",*dword)); | |
272 | return 0; | |
273 | } | |
274 | ||
275 | int saa7146_i2c_transfer(struct saa7146_dev *dev, const struct i2c_msg *msgs, int num, int retries) | |
276 | { | |
277 | int i = 0, count = 0; | |
278 | u32* buffer = dev->d_i2c.cpu_addr; | |
279 | int err = 0; | |
280 | int address_err = 0; | |
281 | int short_delay = 0; | |
282 | ||
283 | if (down_interruptible (&dev->i2c_lock)) | |
284 | return -ERESTARTSYS; | |
285 | ||
286 | for(i=0;i<num;i++) { | |
287 | DEB_I2C(("msg:%d/%d\n",i+1,num)); | |
288 | } | |
289 | ||
290 | /* prepare the message(s), get number of u32s to transfer */ | |
291 | count = saa7146_i2c_msg_prepare(msgs, num, buffer); | |
292 | if ( 0 > count ) { | |
293 | err = -1; | |
294 | goto out; | |
295 | } | |
296 | ||
297 | if ( count > 3 || 0 != (SAA7146_I2C_SHORT_DELAY & dev->ext->flags) ) | |
298 | short_delay = 1; | |
299 | ||
300 | do { | |
301 | /* reset the i2c-device if necessary */ | |
302 | err = saa7146_i2c_reset(dev); | |
303 | if ( 0 > err ) { | |
304 | DEB_I2C(("could not reset i2c-device.\n")); | |
305 | goto out; | |
306 | } | |
307 | ||
308 | /* write out the u32s one after another */ | |
309 | for(i = 0; i < count; i++) { | |
310 | err = saa7146_i2c_writeout(dev, &buffer[i], short_delay); | |
311 | if ( 0 != err) { | |
312 | /* this one is unsatisfying: some i2c slaves on some | |
313 | dvb cards don't acknowledge correctly, so the saa7146 | |
314 | thinks that an address error occured. in that case, the | |
315 | transaction should be retrying, even if an address error | |
316 | occured. analog saa7146 based cards extensively rely on | |
317 | i2c address probing, however, and address errors indicate that a | |
318 | device is really *not* there. retrying in that case | |
319 | increases the time the device needs to probe greatly, so | |
320 | it should be avoided. because of the fact, that only | |
321 | analog based cards use irq based i2c transactions (for dvb | |
322 | cards, this screwes up other interrupt sources), we bail out | |
323 | completely for analog cards after an address error and trust | |
324 | the saa7146 address error detection. */ | |
325 | if ( -EREMOTEIO == err ) { | |
326 | if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) { | |
327 | goto out; | |
328 | } | |
329 | address_err++; | |
330 | } | |
331 | DEB_I2C(("error while sending message(s). starting again.\n")); | |
332 | break; | |
333 | } | |
334 | } | |
335 | if( 0 == err ) { | |
336 | err = num; | |
337 | break; | |
338 | } | |
339 | ||
340 | /* delay a bit before retrying */ | |
341 | msleep(10); | |
342 | ||
343 | } while (err != num && retries--); | |
344 | ||
345 | /* if every retry had an address error, exit right away */ | |
346 | if (address_err == retries) { | |
347 | goto out; | |
348 | } | |
349 | ||
350 | /* if any things had to be read, get the results */ | |
351 | if ( 0 != saa7146_i2c_msg_cleanup(msgs, num, buffer)) { | |
352 | DEB_I2C(("could not cleanup i2c-message.\n")); | |
353 | err = -1; | |
354 | goto out; | |
355 | } | |
356 | ||
357 | /* return the number of delivered messages */ | |
358 | DEB_I2C(("transmission successful. (msg:%d).\n",err)); | |
359 | out: | |
360 | /* another bug in revision 0: the i2c-registers get uploaded randomly by other | |
361 | uploads, so we better clear them out before continueing */ | |
362 | if( 0 == dev->revision ) { | |
363 | u32 zero = 0; | |
364 | saa7146_i2c_reset(dev); | |
365 | if( 0 != saa7146_i2c_writeout(dev, &zero, short_delay)) { | |
366 | INFO(("revision 0 error. this should never happen.\n")); | |
367 | } | |
368 | } | |
369 | ||
370 | up(&dev->i2c_lock); | |
371 | return err; | |
372 | } | |
373 | ||
374 | /* utility functions */ | |
375 | static int saa7146_i2c_xfer(struct i2c_adapter* adapter, struct i2c_msg *msg, int num) | |
376 | { | |
377 | struct saa7146_dev* dev = i2c_get_adapdata(adapter); | |
378 | ||
379 | /* use helper function to transfer data */ | |
380 | return saa7146_i2c_transfer(dev, msg, num, adapter->retries); | |
381 | } | |
382 | ||
383 | ||
384 | /*****************************************************************************/ | |
385 | /* i2c-adapter helper functions */ | |
386 | #include <linux/i2c-id.h> | |
387 | ||
388 | /* exported algorithm data */ | |
389 | static struct i2c_algorithm saa7146_algo = { | |
390 | .name = "saa7146 i2c algorithm", | |
391 | .id = I2C_ALGO_SAA7146, | |
392 | .master_xfer = saa7146_i2c_xfer, | |
393 | .functionality = saa7146_i2c_func, | |
394 | }; | |
395 | ||
396 | int saa7146_i2c_adapter_prepare(struct saa7146_dev *dev, struct i2c_adapter *i2c_adapter, u32 bitrate) | |
397 | { | |
398 | DEB_EE(("bitrate: 0x%08x\n",bitrate)); | |
399 | ||
400 | /* enable i2c-port pins */ | |
401 | saa7146_write(dev, MC1, (MASK_08 | MASK_24)); | |
402 | ||
403 | dev->i2c_bitrate = bitrate; | |
404 | saa7146_i2c_reset(dev); | |
405 | ||
406 | if( NULL != i2c_adapter ) { | |
407 | #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)) | |
408 | i2c_adapter->data = dev; | |
409 | #else | |
410 | BUG_ON(!i2c_adapter->class); | |
411 | i2c_set_adapdata(i2c_adapter,dev); | |
412 | #endif | |
413 | i2c_adapter->algo = &saa7146_algo; | |
414 | i2c_adapter->algo_data = NULL; | |
415 | i2c_adapter->id = I2C_ALGO_SAA7146; | |
416 | i2c_adapter->timeout = SAA7146_I2C_TIMEOUT; | |
417 | i2c_adapter->retries = SAA7146_I2C_RETRIES; | |
418 | } | |
419 | ||
420 | return 0; | |
421 | } |