diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/media/common/saa7146_i2c.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/media/common/saa7146_i2c.c')
-rw-r--r-- | drivers/media/common/saa7146_i2c.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/drivers/media/common/saa7146_i2c.c b/drivers/media/common/saa7146_i2c.c new file mode 100644 index 000000000000..781f23f0cbcc --- /dev/null +++ b/drivers/media/common/saa7146_i2c.c | |||
@@ -0,0 +1,421 @@ | |||
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 | } | ||