1 #include <media/saa7146_vv.h>
3 static u32 saa7146_i2c_func(struct i2c_adapter *adapter)
5 //fm DEB_I2C(("'%s'.\n", adapter->name));
9 | I2C_FUNC_SMBUS_READ_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE
10 | I2C_FUNC_SMBUS_READ_BYTE_DATA | I2C_FUNC_SMBUS_WRITE_BYTE_DATA;
13 /* this function returns the status-register of our i2c-device */
14 static inline u32 saa7146_i2c_status(struct saa7146_dev *dev)
16 u32 iicsta = saa7146_read(dev, I2C_STATUS);
18 DEB_I2C(("status: 0x%08x\n",iicsta));
23 /* this function runs through the i2c-messages and prepares the data to be
24 sent through the saa7146. have a look at the specifications p. 122 ff
25 to understand this. it returns the number of u32s to send, or -1
26 in case of an error. */
27 static int saa7146_i2c_msg_prepare(const struct i2c_msg *m, int num, u32 *op)
31 int mem = 0, op_count = 0;
33 /* first determine size of needed memory */
34 for(i = 0; i < num; i++) {
38 /* worst case: we need one u32 for three bytes to be send
39 plus one extra byte to address the device */
40 mem = 1 + ((mem-1) / 3);
42 /* we assume that op points to a memory of at least SAA7146_I2C_MEM bytes
43 size. if we exceed this limit... */
44 if ( (4*mem) > SAA7146_I2C_MEM ) {
45 //fm DEB_I2C(("cannot prepare i2c-message.\n"));
49 /* be careful: clear out the i2c-mem first */
50 memset(op,0,sizeof(u32)*mem);
52 /* loop through all messages */
53 for(i = 0; i < num; i++) {
55 /* insert the address of the i2c-slave.
56 note: we get 7 bit i2c-addresses,
57 so we have to perform a translation */
58 addr = (m[i].addr*2) + ( (0 != (m[i].flags & I2C_M_RD)) ? 1 : 0);
59 h1 = op_count/3; h2 = op_count%3;
60 op[h1] |= ( (u8)addr << ((3-h2)*8));
61 op[h1] |= (SAA7146_I2C_START << ((3-h2)*2));
64 /* loop through all bytes of message i */
65 for(j = 0; j < m[i].len; j++) {
66 /* insert the data bytes */
67 h1 = op_count/3; h2 = op_count%3;
68 op[h1] |= ( (u32)((u8)m[i].buf[j]) << ((3-h2)*8));
69 op[h1] |= ( SAA7146_I2C_CONT << ((3-h2)*2));
75 /* have a look at the last byte inserted:
76 if it was: ...CONT change it to ...STOP */
77 h1 = (op_count-1)/3; h2 = (op_count-1)%3;
78 if ( SAA7146_I2C_CONT == (0x3 & (op[h1] >> ((3-h2)*2))) ) {
79 op[h1] &= ~(0x2 << ((3-h2)*2));
80 op[h1] |= (SAA7146_I2C_STOP << ((3-h2)*2));
83 /* return the number of u32s to send */
87 /* this functions loops through all i2c-messages. normally, it should determine
88 which bytes were read through the adapter and write them back to the corresponding
89 i2c-message. but instead, we simply write back all bytes.
90 fixme: this could be improved. */
91 static int saa7146_i2c_msg_cleanup(const struct i2c_msg *m, int num, u32 *op)
96 /* loop through all messages */
97 for(i = 0; i < num; i++) {
101 /* loop throgh all bytes of message i */
102 for(j = 0; j < m[i].len; j++) {
103 /* write back all bytes that could have been read */
104 m[i].buf[j] = (op[op_count/3] >> ((3-(op_count%3))*8));
112 /* this functions resets the i2c-device and returns 0 if everything was fine, otherwise -1 */
113 static int saa7146_i2c_reset(struct saa7146_dev *dev)
115 /* get current status */
116 u32 status = saa7146_i2c_status(dev);
118 /* clear registers for sure */
119 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
120 saa7146_write(dev, I2C_TRANSFER, 0);
122 /* check if any operation is still in progress */
123 if ( 0 != ( status & SAA7146_I2C_BUSY) ) {
125 /* yes, kill ongoing operation */
126 DEB_I2C(("busy_state detected.\n"));
128 /* set "ABORT-OPERATION"-bit (bit 7)*/
129 saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07));
130 saa7146_write(dev, MC2, (MASK_00 | MASK_16));
131 msleep(SAA7146_I2C_DELAY);
133 /* clear all error-bits pending; this is needed because p.123, note 1 */
134 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
135 saa7146_write(dev, MC2, (MASK_00 | MASK_16));
136 msleep(SAA7146_I2C_DELAY);
139 /* check if any error is (still) present. (this can be necessary because p.123, note 1) */
140 status = saa7146_i2c_status(dev);
142 if ( dev->i2c_bitrate != status ) {
144 DEB_I2C(("error_state detected. status:0x%08x\n",status));
146 /* Repeat the abort operation. This seems to be necessary
147 after serious protocol errors caused by e.g. the SAA7740 */
148 saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07));
149 saa7146_write(dev, MC2, (MASK_00 | MASK_16));
150 msleep(SAA7146_I2C_DELAY);
152 /* clear all error-bits pending */
153 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
154 saa7146_write(dev, MC2, (MASK_00 | MASK_16));
155 msleep(SAA7146_I2C_DELAY);
157 /* the data sheet says it might be necessary to clear the status
158 twice after an abort */
159 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
160 saa7146_write(dev, MC2, (MASK_00 | MASK_16));
161 msleep(SAA7146_I2C_DELAY);
164 /* if any error is still present, a fatal error has occured ... */
165 status = saa7146_i2c_status(dev);
166 if ( dev->i2c_bitrate != status ) {
167 DEB_I2C(("fatal error. status:0x%08x\n",status));
174 /* this functions writes out the data-byte 'dword' to the i2c-device.
175 it returns 0 if ok, -1 if the transfer failed, -2 if the transfer
176 failed badly (e.g. address error) */
177 static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_delay)
179 u32 status = 0, mc2 = 0;
181 unsigned long timeout;
183 /* write out i2c-command */
184 DEB_I2C(("before: 0x%08x (status: 0x%08x), %d\n",*dword,saa7146_read(dev, I2C_STATUS), dev->i2c_op));
186 if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) {
188 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
189 saa7146_write(dev, I2C_TRANSFER, *dword);
192 SAA7146_IER_ENABLE(dev, MASK_16|MASK_17);
193 saa7146_write(dev, MC2, (MASK_00 | MASK_16));
195 wait_event_interruptible(dev->i2c_wq, dev->i2c_op == 0);
196 if (signal_pending (current)) {
197 /* a signal arrived */
200 status = saa7146_read(dev, I2C_STATUS);
202 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
203 saa7146_write(dev, I2C_TRANSFER, *dword);
204 saa7146_write(dev, MC2, (MASK_00 | MASK_16));
206 /* do not poll for i2c-status before upload is complete */
207 timeout = jiffies + HZ/100 + 1; /* 10ms */
209 mc2 = (saa7146_read(dev, MC2) & 0x1);
213 if (time_after(jiffies,timeout)) {
214 printk(KERN_WARNING "saa7146_i2c_writeout: timed out waiting for MC2\n");
218 /* wait until we get a transfer done or error */
219 timeout = jiffies + HZ/100 + 1; /* 10ms */
220 /* first read usually delivers bogus results... */
221 saa7146_i2c_status(dev);
223 status = saa7146_i2c_status(dev);
224 if ((status & 0x3) != 1)
226 if (time_after(jiffies,timeout)) {
227 /* this is normal when probing the bus
228 * (no answer from nonexisistant device...)
230 DEB_I2C(("saa7146_i2c_writeout: timed out waiting for end of xfer\n"));
233 if (++trial < 50 && short_delay)
240 /* give a detailed status report */
241 if ( 0 != (status & SAA7146_I2C_ERR)) {
243 if( 0 != (status & SAA7146_I2C_SPERR) ) {
244 DEB_I2C(("error due to invalid start/stop condition.\n"));
246 if( 0 != (status & SAA7146_I2C_DTERR) ) {
247 DEB_I2C(("error in data transmission.\n"));
249 if( 0 != (status & SAA7146_I2C_DRERR) ) {
250 DEB_I2C(("error when receiving data.\n"));
252 if( 0 != (status & SAA7146_I2C_AL) ) {
253 DEB_I2C(("error because arbitration lost.\n"));
256 /* we handle address-errors here */
257 if( 0 != (status & SAA7146_I2C_APERR) ) {
258 DEB_I2C(("error in address phase.\n"));
265 /* read back data, just in case we were reading ... */
266 *dword = saa7146_read(dev, I2C_TRANSFER);
268 DEB_I2C(("after: 0x%08x\n",*dword));
272 int saa7146_i2c_transfer(struct saa7146_dev *dev, const struct i2c_msg *msgs, int num, int retries)
274 int i = 0, count = 0;
275 u32* buffer = dev->d_i2c.cpu_addr;
280 if (mutex_lock_interruptible(&dev->i2c_lock))
284 DEB_I2C(("msg:%d/%d\n",i+1,num));
287 /* prepare the message(s), get number of u32s to transfer */
288 count = saa7146_i2c_msg_prepare(msgs, num, buffer);
294 if ( count > 3 || 0 != (SAA7146_I2C_SHORT_DELAY & dev->ext->flags) )
298 /* reset the i2c-device if necessary */
299 err = saa7146_i2c_reset(dev);
301 DEB_I2C(("could not reset i2c-device.\n"));
305 /* write out the u32s one after another */
306 for(i = 0; i < count; i++) {
307 err = saa7146_i2c_writeout(dev, &buffer[i], short_delay);
309 /* this one is unsatisfying: some i2c slaves on some
310 dvb cards don't acknowledge correctly, so the saa7146
311 thinks that an address error occured. in that case, the
312 transaction should be retrying, even if an address error
313 occured. analog saa7146 based cards extensively rely on
314 i2c address probing, however, and address errors indicate that a
315 device is really *not* there. retrying in that case
316 increases the time the device needs to probe greatly, so
317 it should be avoided. because of the fact, that only
318 analog based cards use irq based i2c transactions (for dvb
319 cards, this screwes up other interrupt sources), we bail out
320 completely for analog cards after an address error and trust
321 the saa7146 address error detection. */
322 if ( -EREMOTEIO == err ) {
323 if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) {
328 DEB_I2C(("error while sending message(s). starting again.\n"));
337 /* delay a bit before retrying */
340 } while (err != num && retries--);
342 /* if every retry had an address error, exit right away */
343 if (address_err == retries) {
347 /* if any things had to be read, get the results */
348 if ( 0 != saa7146_i2c_msg_cleanup(msgs, num, buffer)) {
349 DEB_I2C(("could not cleanup i2c-message.\n"));
354 /* return the number of delivered messages */
355 DEB_I2C(("transmission successful. (msg:%d).\n",err));
357 /* another bug in revision 0: the i2c-registers get uploaded randomly by other
358 uploads, so we better clear them out before continueing */
359 if( 0 == dev->revision ) {
361 saa7146_i2c_reset(dev);
362 if( 0 != saa7146_i2c_writeout(dev, &zero, short_delay)) {
363 INFO(("revision 0 error. this should never happen.\n"));
367 mutex_unlock(&dev->i2c_lock);
371 /* utility functions */
372 static int saa7146_i2c_xfer(struct i2c_adapter* adapter, struct i2c_msg *msg, int num)
374 struct saa7146_dev* dev = i2c_get_adapdata(adapter);
376 /* use helper function to transfer data */
377 return saa7146_i2c_transfer(dev, msg, num, adapter->retries);
381 /*****************************************************************************/
382 /* i2c-adapter helper functions */
383 #include <linux/i2c-id.h>
385 /* exported algorithm data */
386 static struct i2c_algorithm saa7146_algo = {
387 .master_xfer = saa7146_i2c_xfer,
388 .functionality = saa7146_i2c_func,
391 int saa7146_i2c_adapter_prepare(struct saa7146_dev *dev, struct i2c_adapter *i2c_adapter, u32 bitrate)
393 DEB_EE(("bitrate: 0x%08x\n",bitrate));
395 /* enable i2c-port pins */
396 saa7146_write(dev, MC1, (MASK_08 | MASK_24));
398 dev->i2c_bitrate = bitrate;
399 saa7146_i2c_reset(dev);
401 if( NULL != i2c_adapter ) {
402 BUG_ON(!i2c_adapter->class);
403 i2c_set_adapdata(i2c_adapter,dev);
404 i2c_adapter->dev.parent = &dev->pci->dev;
405 i2c_adapter->algo = &saa7146_algo;
406 i2c_adapter->algo_data = NULL;
407 i2c_adapter->id = I2C_HW_SAA7146;
408 i2c_adapter->timeout = SAA7146_I2C_TIMEOUT;
409 i2c_adapter->retries = SAA7146_I2C_RETRIES;