433 строки
13 KiB
C
433 строки
13 KiB
C
#include <media/saa7146_vv.h>
|
|
|
|
static u32 saa7146_i2c_func(struct i2c_adapter *adapter)
|
|
{
|
|
//fm 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 ) {
|
|
//fm 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 throgh 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 occured ... */
|
|
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;
|
|
|
|
printk(KERN_WARNING "%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)) {
|
|
printk(KERN_WARNING "%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...)
|
|
*/
|
|
printk(KERN_WARNING "%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 address_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 occured. in that case, the
|
|
transaction should be retrying, even if an address error
|
|
occured. 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. because of the fact, that only
|
|
analog based cards use irq based i2c transactions (for dvb
|
|
cards, this screwes up other interrupt sources), we bail out
|
|
completely for analog cards after an address error and trust
|
|
the saa7146 address error detection. */
|
|
if ( -EREMOTEIO == err ) {
|
|
if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) {
|
|
goto out;
|
|
}
|
|
address_err++;
|
|
}
|
|
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--);
|
|
|
|
/* if every retry had an address error, exit right away */
|
|
if (address_err == retries) {
|
|
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 continueing */
|
|
if( 0 == dev->revision ) {
|
|
__le32 zero = 0;
|
|
saa7146_i2c_reset(dev);
|
|
if( 0 != saa7146_i2c_writeout(dev, &zero, short_delay)) {
|
|
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 saa7146_dev* dev = i2c_get_adapdata(adapter);
|
|
|
|
/* use helper function to transfer data */
|
|
return saa7146_i2c_transfer(dev, msg, num, adapter->retries);
|
|
}
|
|
|
|
|
|
/*****************************************************************************/
|
|
/* i2c-adapter helper functions */
|
|
#include <linux/i2c-id.h>
|
|
|
|
/* 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( NULL != i2c_adapter ) {
|
|
BUG_ON(!i2c_adapter->class);
|
|
i2c_set_adapdata(i2c_adapter,dev);
|
|
i2c_adapter->dev.parent = &dev->pci->dev;
|
|
i2c_adapter->algo = &saa7146_algo;
|
|
i2c_adapter->algo_data = NULL;
|
|
i2c_adapter->id = I2C_HW_SAA7146;
|
|
i2c_adapter->timeout = SAA7146_I2C_TIMEOUT;
|
|
i2c_adapter->retries = SAA7146_I2C_RETRIES;
|
|
}
|
|
|
|
return 0;
|
|
}
|