- no blank before trailing delimiter
- whitespace at end of input line
- sections out of conventional order
- normalizing date format
- AUTHORS section without An macro
Some i2c controller hardware does not provide a way to do individual START,
REPEAT-START and STOP actions on the i2c bus. Instead, they can only do
a complete transfer as a single operation. Typically they can do either
START-data-STOP or START-data-REPEATSTART-data-STOP. In the i2c driver
framework, this corresponds to the iicbus_transfer method. In the userland
interface they are initiated with the I2CRDWR ioctl command.
These changes add a new 'tr' mode which can be specified with the '-m'
command line option. This mode should work on all hardware; when an i2c
controller driver doesn't directly support the iicbus_transfer method,
code in the i2c driver framework uses the lower-level START/REPEAT/STOP
methods to implement the transfer. After this new mode has gotten some
testing on various hardware, the 'tr' mode should probably become the
new default mode.
PR: 189914
The code went to a lot of trouble to issue either a start+stop condition
or a repeated start condition only to follow it with a stop condition
and a read(2) call that issues a new start condition.
So, fix the read in I2C_MODE_REPEATED_START mode by using I2CREAD ioctl
within the running transaction. This obviously requires that the slave
address has the read bit set which was not required before.
Another problem was with width parameter of zero and
I2C_MODE_REPEATED_START mode. In that case we issued a repeated start
without any preceding start.
While here, remove the redundant (unused) argument to I2CSTOP throughout
the program.
Also, clarify the meaning of -w option, especially "-w 0", in the manual
page.
Reviewed by: no one
Differential Revision: https://reviews.freebsd.org/D12331
