459dfa0dd2
First, SCL low timeout is set to 25 milliseconds by default as opposed to 1 millisecond before. The new value is based on the SMBus specification. The timeout can be changed on a per bus basis using dev.iicbb.N.scl_low_timeout sysctl. The driver uses DELAY to wait for high SCL up to 1 millisecond, then it switches to pause_sbt(SBT_1MS) for the rest of the timeout. While here I made a number of other changes. 'udelay' that's used for timing clock and data signals is now calculated based on the requested bus frequency (dev.iicbus.N.frequency) instead of being hardcoded to 10 microseconds. The calculations are done in such a fashion that the default bus frequency of 100000 is converted to udelay of 10 us. This is for backward compatibility. The actual frequency will be less than a quarter (I think) of the requested frequency. Also, I added detection of stuck low SCL in a few places. Previously, the code would just carry on after the SCL low timeout and that might potentially lead to misinterpreted bits. Finally, I fixed several style issues near the code that I changed. Many more are still remaining. Tested by accessing HTU21 temperature and humidity sensor in this setup: superio0: <Nuvoton NCT5104D/NCT6102D/NCT6106D (rev. B+)> at port 0x2e-0x2f on isa0 gpio1: <Nuvoton GPIO controller> at GPIO ldn 0x07 on superio0 pcib0: allocated type 4 (0x220-0x226) for rid 0 of gpio1 gpiobus1: <GPIO bus> on gpio1 gpioiic0: <GPIO I2C bit-banging driver> at pins 14-15 on gpiobus1 gpioiic0: SCL pin: 14, SDA pin: 15 iicbb0: <I2C bit-banging driver> on gpioiic0 iicbus0: <Philips I2C bus> on iicbb0 master-only iic0: <I2C generic I/O> on iicbus0 Discussed with: ian, imp MFC after: 3 weeks Differential Revision: https://reviews.freebsd.org/D22109 |
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| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| stand | ||
| sys | ||
| targets | ||
| tests | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| .arcconfig | ||
| .arclint | ||
| .cirrus.yml | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| Makefile.libcompat | ||
| Makefile.sys.inc | ||
| ObsoleteFiles.inc | ||
| README | ||
| README.md | ||
| RELNOTES | ||
| UPDATING | ||
FreeBSD Source:
This is the top level of the FreeBSD source directory. This file
was last revised on:
FreeBSD
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html, and https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information, including setting make(1) variables.
Source Roadmap:
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cddl Various commands and libraries under the Common Development
and Distribution License.
contrib Packages contributed by 3rd parties.
crypto Cryptography stuff (see crypto/README).
etc Template files for /etc.
gnu Various commands and libraries under the GNU Public License.
Please see gnu/COPYING* for more information.
include System include files.
kerberos5 Kerberos5 (Heimdal) package.
lib System libraries.
libexec System daemons.
release Release building Makefile & associated tools.
rescue Build system for statically linked /rescue utilities.
sbin System commands.
secure Cryptographic libraries and commands.
share Shared resources.
stand Boot loader sources.
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sys/<arch>/conf Kernel configuration files. GENERIC is the configuration
used in release builds. NOTES contains documentation of
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