- Add FDT probe code.
- Do i2c transfers with exclusive bus ownership.
- Use config_intrhook_oneshot() to defer chip setup because some i2c
busses can't do transfers without interrupts.
- Add a detach() routine.
- Add to module build.
This driver supports only basic timekeeping functionality. It completely
replaces the ds133x driver. It can also replace the ds1374 driver, but that
will take a few other changes in MIPS code and config, and will be committed
separately. It does NOT replace the existing ds1307 driver, which provides
access to some of the extended features on the 1307 chip, such as controlling
the square wave output signal. If both ds1307 and ds13rtc drivers are
present, the ds1307 driver will outbid and win control of the device.
This driver can be configured with FDT data, or by using hints on non-FDT
systems. In addition to the standard hints for i2c devices, it requires
a "chiptype" string of the form "dallas,ds13xx" where 'xx' is the chip id
(i.e., the same format as FDT compat strings).
The driver currently supports chips that are fully compliant with the
JEDEC SPD / EEPROM / TS standard (JEDEC Standard 21-C,
TSE2002 Specification, frequenlty referred to as JEDEC JC 42.4).
Additionally some chips from STMicroelectronics are supported as well.
They are compliant except for their Device ID pattern.
Given the continued lack of any common sensor infrastructure, the driver
uses an ad-hoc sysctl to report the temperature.
Reviewed by: wblock (documentation)
MFC after: 2 weeks
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D8174
