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px4-firmware
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Add a bus reset on I2C error. Also add a mechanism for automated retries of operations.

This commit is contained in:
px4dev 2012-08-22 22:25:10 -07:00
parent a3b78163c3
commit a0b9c056d7
2 changed files with 37 additions and 19 deletions
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50
apps/drivers/device/i2c.cpp
View File

@ -53,6 +53,7 @@ I2C::I2C(const char *name,
CDev(name, devname, irq),
// public
// protected
_retries(0),
// private
_bus(bus),
_address(address),
@ -117,33 +118,44 @@ I2C::transfer(uint8_t *send, unsigned send_len, uint8_t *recv, unsigned recv_len
struct i2c_msg_s msgv[2];
unsigned msgs;
int ret;
unsigned tries;
// debug("transfer out %p/%u in %p/%u", send, send_len, recv, recv_len);
do {
// debug("transfer out %p/%u in %p/%u", send, send_len, recv, recv_len);
msgs = 0;
msgs = 0;
if (send_len > 0) {
msgv[msgs].addr = _address;
msgv[msgs].flags = 0;
msgv[msgs].buffer = send;
msgv[msgs].length = send_len;
msgs++;
}
if (send_len > 0) {
msgv[msgs].addr = _address;
msgv[msgs].flags = 0;
msgv[msgs].buffer = send;
msgv[msgs].length = send_len;
msgs++;
}
if (recv_len > 0) {
msgv[msgs].addr = _address;
msgv[msgs].flags = I2C_M_READ;
msgv[msgs].buffer = recv;
msgv[msgs].length = recv_len;
msgs++;
}
if (recv_len > 0) {
msgv[msgs].addr = _address;
msgv[msgs].flags = I2C_M_READ;
msgv[msgs].buffer = recv;
msgv[msgs].length = recv_len;
msgs++;
}
if (msgs == 0)
return -EINVAL;
if (msgs == 0)
return -EINVAL;
ret = I2C_TRANSFER(_dev, &msgv[0], msgs);
ret = I2C_TRANSFER(_dev, &msgv[0], msgs);
if (ret == OK)
break;
// reset the I2C bus to unwedge on error
up_i2creset(_dev);
} while (tries++ < _retries);
return ret;
}
} // namespace device

6
apps/drivers/device/i2c.h
View File

@ -52,6 +52,12 @@ class __EXPORT I2C : public CDev
{
protected:
/**
* The number of times a read or write operation will be retried on
* error.
*/
unsigned _retries;
/**
* @ Constructor
*