123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423 |
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #include <media/saa7146_vv.h>
- static u32 saa7146_i2c_func(struct i2c_adapter *adapter)
- {
- /* DEB_I2C("'%s'\n", adapter->name); */
- return I2C_FUNC_I2C
- | I2C_FUNC_SMBUS_QUICK
- | I2C_FUNC_SMBUS_READ_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE
- | I2C_FUNC_SMBUS_READ_BYTE_DATA | I2C_FUNC_SMBUS_WRITE_BYTE_DATA;
- }
- /* this function returns the status-register of our i2c-device */
- static inline u32 saa7146_i2c_status(struct saa7146_dev *dev)
- {
- u32 iicsta = saa7146_read(dev, I2C_STATUS);
- /* DEB_I2C("status: 0x%08x\n", iicsta); */
- return iicsta;
- }
- /* this function runs through the i2c-messages and prepares the data to be
- sent through the saa7146. have a look at the specifications p. 122 ff
- to understand this. it returns the number of u32s to send, or -1
- in case of an error. */
- static int saa7146_i2c_msg_prepare(const struct i2c_msg *m, int num, __le32 *op)
- {
- int h1, h2;
- int i, j, addr;
- int mem = 0, op_count = 0;
- /* first determine size of needed memory */
- for(i = 0; i < num; i++) {
- mem += m[i].len + 1;
- }
- /* worst case: we need one u32 for three bytes to be send
- plus one extra byte to address the device */
- mem = 1 + ((mem-1) / 3);
- /* we assume that op points to a memory of at least
- * SAA7146_I2C_MEM bytes size. if we exceed this limit...
- */
- if ((4 * mem) > SAA7146_I2C_MEM) {
- /* DEB_I2C("cannot prepare i2c-message\n"); */
- return -ENOMEM;
- }
- /* be careful: clear out the i2c-mem first */
- memset(op,0,sizeof(__le32)*mem);
- /* loop through all messages */
- for(i = 0; i < num; i++) {
- /* insert the address of the i2c-slave.
- note: we get 7 bit i2c-addresses,
- so we have to perform a translation */
- addr = (m[i].addr*2) + ( (0 != (m[i].flags & I2C_M_RD)) ? 1 : 0);
- h1 = op_count/3; h2 = op_count%3;
- op[h1] |= cpu_to_le32( (u8)addr << ((3-h2)*8));
- op[h1] |= cpu_to_le32(SAA7146_I2C_START << ((3-h2)*2));
- op_count++;
- /* loop through all bytes of message i */
- for(j = 0; j < m[i].len; j++) {
- /* insert the data bytes */
- h1 = op_count/3; h2 = op_count%3;
- op[h1] |= cpu_to_le32( (u32)((u8)m[i].buf[j]) << ((3-h2)*8));
- op[h1] |= cpu_to_le32( SAA7146_I2C_CONT << ((3-h2)*2));
- op_count++;
- }
- }
- /* have a look at the last byte inserted:
- if it was: ...CONT change it to ...STOP */
- h1 = (op_count-1)/3; h2 = (op_count-1)%3;
- if ( SAA7146_I2C_CONT == (0x3 & (le32_to_cpu(op[h1]) >> ((3-h2)*2))) ) {
- op[h1] &= ~cpu_to_le32(0x2 << ((3-h2)*2));
- op[h1] |= cpu_to_le32(SAA7146_I2C_STOP << ((3-h2)*2));
- }
- /* return the number of u32s to send */
- return mem;
- }
- /* this functions loops through all i2c-messages. normally, it should determine
- which bytes were read through the adapter and write them back to the corresponding
- i2c-message. but instead, we simply write back all bytes.
- fixme: this could be improved. */
- static int saa7146_i2c_msg_cleanup(const struct i2c_msg *m, int num, __le32 *op)
- {
- int i, j;
- int op_count = 0;
- /* loop through all messages */
- for(i = 0; i < num; i++) {
- op_count++;
- /* loop through all bytes of message i */
- for(j = 0; j < m[i].len; j++) {
- /* write back all bytes that could have been read */
- m[i].buf[j] = (le32_to_cpu(op[op_count/3]) >> ((3-(op_count%3))*8));
- op_count++;
- }
- }
- return 0;
- }
- /* this functions resets the i2c-device and returns 0 if everything was fine, otherwise -1 */
- static int saa7146_i2c_reset(struct saa7146_dev *dev)
- {
- /* get current status */
- u32 status = saa7146_i2c_status(dev);
- /* clear registers for sure */
- saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
- saa7146_write(dev, I2C_TRANSFER, 0);
- /* check if any operation is still in progress */
- if ( 0 != ( status & SAA7146_I2C_BUSY) ) {
- /* yes, kill ongoing operation */
- DEB_I2C("busy_state detected\n");
- /* set "ABORT-OPERATION"-bit (bit 7)*/
- saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07));
- saa7146_write(dev, MC2, (MASK_00 | MASK_16));
- msleep(SAA7146_I2C_DELAY);
- /* clear all error-bits pending; this is needed because p.123, note 1 */
- saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
- saa7146_write(dev, MC2, (MASK_00 | MASK_16));
- msleep(SAA7146_I2C_DELAY);
- }
- /* check if any error is (still) present. (this can be necessary because p.123, note 1) */
- status = saa7146_i2c_status(dev);
- if ( dev->i2c_bitrate != status ) {
- DEB_I2C("error_state detected. status:0x%08x\n", status);
- /* Repeat the abort operation. This seems to be necessary
- after serious protocol errors caused by e.g. the SAA7740 */
- saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07));
- saa7146_write(dev, MC2, (MASK_00 | MASK_16));
- msleep(SAA7146_I2C_DELAY);
- /* clear all error-bits pending */
- saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
- saa7146_write(dev, MC2, (MASK_00 | MASK_16));
- msleep(SAA7146_I2C_DELAY);
- /* the data sheet says it might be necessary to clear the status
- twice after an abort */
- saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
- saa7146_write(dev, MC2, (MASK_00 | MASK_16));
- msleep(SAA7146_I2C_DELAY);
- }
- /* if any error is still present, a fatal error has occurred ... */
- status = saa7146_i2c_status(dev);
- if ( dev->i2c_bitrate != status ) {
- DEB_I2C("fatal error. status:0x%08x\n", status);
- return -1;
- }
- return 0;
- }
- /* this functions writes out the data-byte 'dword' to the i2c-device.
- it returns 0 if ok, -1 if the transfer failed, -2 if the transfer
- failed badly (e.g. address error) */
- static int saa7146_i2c_writeout(struct saa7146_dev *dev, __le32 *dword, int short_delay)
- {
- u32 status = 0, mc2 = 0;
- int trial = 0;
- unsigned long timeout;
- /* write out i2c-command */
- DEB_I2C("before: 0x%08x (status: 0x%08x), %d\n",
- *dword, saa7146_read(dev, I2C_STATUS), dev->i2c_op);
- if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) {
- saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
- saa7146_write(dev, I2C_TRANSFER, le32_to_cpu(*dword));
- dev->i2c_op = 1;
- SAA7146_ISR_CLEAR(dev, MASK_16|MASK_17);
- SAA7146_IER_ENABLE(dev, MASK_16|MASK_17);
- saa7146_write(dev, MC2, (MASK_00 | MASK_16));
- timeout = HZ/100 + 1; /* 10ms */
- timeout = wait_event_interruptible_timeout(dev->i2c_wq, dev->i2c_op == 0, timeout);
- if (timeout == -ERESTARTSYS || dev->i2c_op) {
- SAA7146_IER_DISABLE(dev, MASK_16|MASK_17);
- SAA7146_ISR_CLEAR(dev, MASK_16|MASK_17);
- if (timeout == -ERESTARTSYS)
- /* a signal arrived */
- return -ERESTARTSYS;
- pr_warn("%s %s [irq]: timed out waiting for end of xfer\n",
- dev->name, __func__);
- return -EIO;
- }
- status = saa7146_read(dev, I2C_STATUS);
- } else {
- saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
- saa7146_write(dev, I2C_TRANSFER, le32_to_cpu(*dword));
- saa7146_write(dev, MC2, (MASK_00 | MASK_16));
- /* do not poll for i2c-status before upload is complete */
- timeout = jiffies + HZ/100 + 1; /* 10ms */
- while(1) {
- mc2 = (saa7146_read(dev, MC2) & 0x1);
- if( 0 != mc2 ) {
- break;
- }
- if (time_after(jiffies,timeout)) {
- pr_warn("%s %s: timed out waiting for MC2\n",
- dev->name, __func__);
- return -EIO;
- }
- }
- /* wait until we get a transfer done or error */
- timeout = jiffies + HZ/100 + 1; /* 10ms */
- /* first read usually delivers bogus results... */
- saa7146_i2c_status(dev);
- while(1) {
- status = saa7146_i2c_status(dev);
- if ((status & 0x3) != 1)
- break;
- if (time_after(jiffies,timeout)) {
- /* this is normal when probing the bus
- * (no answer from nonexisistant device...)
- */
- pr_warn("%s %s [poll]: timed out waiting for end of xfer\n",
- dev->name, __func__);
- return -EIO;
- }
- if (++trial < 50 && short_delay)
- udelay(10);
- else
- msleep(1);
- }
- }
- /* give a detailed status report */
- if ( 0 != (status & (SAA7146_I2C_SPERR | SAA7146_I2C_APERR |
- SAA7146_I2C_DTERR | SAA7146_I2C_DRERR |
- SAA7146_I2C_AL | SAA7146_I2C_ERR |
- SAA7146_I2C_BUSY)) ) {
- if ( 0 == (status & SAA7146_I2C_ERR) ||
- 0 == (status & SAA7146_I2C_BUSY) ) {
- /* it may take some time until ERR goes high - ignore */
- DEB_I2C("unexpected i2c status %04x\n", status);
- }
- if( 0 != (status & SAA7146_I2C_SPERR) ) {
- DEB_I2C("error due to invalid start/stop condition\n");
- }
- if( 0 != (status & SAA7146_I2C_DTERR) ) {
- DEB_I2C("error in data transmission\n");
- }
- if( 0 != (status & SAA7146_I2C_DRERR) ) {
- DEB_I2C("error when receiving data\n");
- }
- if( 0 != (status & SAA7146_I2C_AL) ) {
- DEB_I2C("error because arbitration lost\n");
- }
- /* we handle address-errors here */
- if( 0 != (status & SAA7146_I2C_APERR) ) {
- DEB_I2C("error in address phase\n");
- return -EREMOTEIO;
- }
- return -EIO;
- }
- /* read back data, just in case we were reading ... */
- *dword = cpu_to_le32(saa7146_read(dev, I2C_TRANSFER));
- DEB_I2C("after: 0x%08x\n", *dword);
- return 0;
- }
- static int saa7146_i2c_transfer(struct saa7146_dev *dev, const struct i2c_msg *msgs, int num, int retries)
- {
- int i = 0, count = 0;
- __le32 *buffer = dev->d_i2c.cpu_addr;
- int err = 0;
- int short_delay = 0;
- if (mutex_lock_interruptible(&dev->i2c_lock))
- return -ERESTARTSYS;
- for(i=0;i<num;i++) {
- DEB_I2C("msg:%d/%d\n", i+1, num);
- }
- /* prepare the message(s), get number of u32s to transfer */
- count = saa7146_i2c_msg_prepare(msgs, num, buffer);
- if ( 0 > count ) {
- err = -1;
- goto out;
- }
- if ( count > 3 || 0 != (SAA7146_I2C_SHORT_DELAY & dev->ext->flags) )
- short_delay = 1;
- do {
- /* reset the i2c-device if necessary */
- err = saa7146_i2c_reset(dev);
- if ( 0 > err ) {
- DEB_I2C("could not reset i2c-device\n");
- goto out;
- }
- /* write out the u32s one after another */
- for(i = 0; i < count; i++) {
- err = saa7146_i2c_writeout(dev, &buffer[i], short_delay);
- if ( 0 != err) {
- /* this one is unsatisfying: some i2c slaves on some
- dvb cards don't acknowledge correctly, so the saa7146
- thinks that an address error occurred. in that case, the
- transaction should be retrying, even if an address error
- occurred. analog saa7146 based cards extensively rely on
- i2c address probing, however, and address errors indicate that a
- device is really *not* there. retrying in that case
- increases the time the device needs to probe greatly, so
- it should be avoided. So we bail out in irq mode after an
- address error and trust the saa7146 address error detection. */
- if (-EREMOTEIO == err && 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags))
- goto out;
- DEB_I2C("error while sending message(s). starting again\n");
- break;
- }
- }
- if( 0 == err ) {
- err = num;
- break;
- }
- /* delay a bit before retrying */
- msleep(10);
- } while (err != num && retries--);
- /* quit if any error occurred */
- if (err != num)
- goto out;
- /* if any things had to be read, get the results */
- if ( 0 != saa7146_i2c_msg_cleanup(msgs, num, buffer)) {
- DEB_I2C("could not cleanup i2c-message\n");
- err = -1;
- goto out;
- }
- /* return the number of delivered messages */
- DEB_I2C("transmission successful. (msg:%d)\n", err);
- out:
- /* another bug in revision 0: the i2c-registers get uploaded randomly by other
- uploads, so we better clear them out before continuing */
- if( 0 == dev->revision ) {
- __le32 zero = 0;
- saa7146_i2c_reset(dev);
- if( 0 != saa7146_i2c_writeout(dev, &zero, short_delay)) {
- pr_info("revision 0 error. this should never happen\n");
- }
- }
- mutex_unlock(&dev->i2c_lock);
- return err;
- }
- /* utility functions */
- static int saa7146_i2c_xfer(struct i2c_adapter* adapter, struct i2c_msg *msg, int num)
- {
- struct v4l2_device *v4l2_dev = i2c_get_adapdata(adapter);
- struct saa7146_dev *dev = to_saa7146_dev(v4l2_dev);
- /* use helper function to transfer data */
- return saa7146_i2c_transfer(dev, msg, num, adapter->retries);
- }
- /*****************************************************************************/
- /* i2c-adapter helper functions */
- /* exported algorithm data */
- static struct i2c_algorithm saa7146_algo = {
- .master_xfer = saa7146_i2c_xfer,
- .functionality = saa7146_i2c_func,
- };
- int saa7146_i2c_adapter_prepare(struct saa7146_dev *dev, struct i2c_adapter *i2c_adapter, u32 bitrate)
- {
- DEB_EE("bitrate: 0x%08x\n", bitrate);
- /* enable i2c-port pins */
- saa7146_write(dev, MC1, (MASK_08 | MASK_24));
- dev->i2c_bitrate = bitrate;
- saa7146_i2c_reset(dev);
- if (i2c_adapter) {
- i2c_set_adapdata(i2c_adapter, &dev->v4l2_dev);
- i2c_adapter->dev.parent = &dev->pci->dev;
- i2c_adapter->algo = &saa7146_algo;
- i2c_adapter->algo_data = NULL;
- i2c_adapter->timeout = SAA7146_I2C_TIMEOUT;
- i2c_adapter->retries = SAA7146_I2C_RETRIES;
- }
- return 0;
- }
|