When iicbus is attached as child of Designware I2C controller it scans all
ACPI nodes for "I2C Serial Bus Connection Resource Descriptor" described
in section 19.6.57 of ACPI specs.
If such a descriptor is found, I2C child is added to iicbus, it's I2C
address, IRQ resource and ACPI handle are added to ivars. Existing
ACPI bus-hosted child is deleted afterwards.
The driver also installs so called "I2C address space handler" which is
disabled by default as nontested.
Set hw.iicbus.enable_acpi_space_handler loader tunable to 1 to enable it.
Reviewed by: markj
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D22901
An i2c bus can be divided into segments which can be selectively connected
and disconnected from the main bus. This is usually done to enable using
multiple slave devices having the same address, by isolating the devices
onto separate bus segments, only one of which is connected to the main bus
at once.
There are several types of i2c bus muxes, which break down into two general
categories...
- Muxes which are themselves i2c slaves. These devices respond to i2c
commands on their upstream bus, and based on those commands, connect
various downstream buses to the upstream. In newbus terms, they are both
a child of an iicbus and the parent of one or more iicbus instances.
- Muxes which are not i2c devices themselves. Such devices are part of the
i2c bus electrically, but in newbus terms their parent is some other
bus. The association with the upstream bus must be established by
separate metadata (such as FDT data).
In both cases, the mux driver has one or more iicbus child instances
representing the downstream buses. The mux driver implements the iicbus_if
interface, as if it were an iichb host bridge/i2c controller driver. It
services the IO requests sent to it by forwarding them to the iicbus
instance representing the upstream bus, after electrically connecting the
upstream bus to the downstream bus that hosts the i2c slave device which
made the IO request.
The net effect is automatic mux switching which is transparent to slaves on
the downstream buses. They just do i2c IO they way they normally do, and the
bus is electrically connected for the duration of the IO and then idled when
it is complete.
The existing iicbus_if callback() method is enhanced so that the parameter
passed to it can be a struct which contains a device_t for the requesting
bus and slave devices. This change is done by adding a flag that indicates
the extra values are present, and making the flags field the first field of
a new args struct. If the flag is set, the iichb or mux driver can recast
the pointer-to-flags into a pointer-to-struct and access the extra
fields. Thus abi compatibility with older drivers is retained (but a mux
cannot exist on the bus with the older iicbus driver in use.)
A new set of core support routines exists in iicbus.c. This code will help
implement mux drivers for any type of mux hardware by supplying all the
boilerplate code that forwards IO requests upstream. It also has code for
parsing metadata and instantiating the child iicbus instances based on it.
Two new hardware mux drivers are added. The ltc430x driver supports the
LTC4305/4306 mux chips which are controlled via i2c commands. The
iic_gpiomux driver supports any mux hardware which is controlled by
manipulating the state of one or more gpio pins. Test Plan
Tested locally using a variety of mux'd bus configurations involving both
ltc4305 and a homebrew gpio-controlled mux. Tested configurations included
cascaded muxes (unlikely in the real world, but useful to prove that 'it all
just works' in terms of the automatic switching and upstream forwarding of
IO requests).
Instances of the device can be configured using hints or FDT data.
Interfaces to reconfigure the chip and extract voltage measurements from
it are available via sysctl(8).
The already-listed APMC0D0F ID belongs to the Ampere eMAG aarch64
platform, but ACPI support was not even built on aarch64.
Submitted by: Greg V <greg_unrelenting.technology>
Differential Revision: https://reviews.freebsd.org/D21059
The jedec_ts(4) driver has been marked as deprecated in stable/11, and is
now being removed from -HEAD. Add a notice in UPDATING, and update the few
remaining references (regarding jedec_dimm(4)'s compatibility and history)
to reflect the fact that jedec_ts(4) is now deleted.
Reviewed by: avg
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D16537
imcsmb(4) provides smbus(4) support for the SMBus controller functionality
in the integrated Memory Controllers (iMCs) embedded in Intel Sandybridge-
Xeon, Ivybridge-Xeon, Haswell-Xeon, and Broadwell-Xeon CPUs. Each CPU
implements one or more iMCs, depending on the number of cores; each iMC
implements two SMBus controllers (iMC-SMBs).
*** IMPORTANT NOTE ***
Because motherboard firmware or the BMC might try to use the iMC-SMBs for
monitoring DIMM temperatures and/or managing an NVDIMM, the driver might
need to temporarily disable those functions, or take a hardware interlock,
before using the iMC-SMBs. Details on how to do this may vary from board to
board, and the procedure may be proprietary. It is strongly suggested that
anyone wishing to use this driver contact their motherboard vendor, and
modify the driver as described in the manual page and in the driver itself.
(For what it's worth, the driver as-is has been tested on various SuperMicro
motherboards.)
Reviewed by: avg, jhb
MFC after: 1 week
Relnotes: yes
Sponsored by: Panasas
Differential Revision: https://reviews.freebsd.org/D14447
Discussed with: avg, ian, jhb
Tested by: allanjude (previous version), Panasas
the iicbus module for FDT-based systems.
The primary motivation for this is that host controller drivers which
declare DRIVER_MODULE(ofw_iicbus, thisdriver, etc, etc) now only need a
single MODULE_DEPEND(thisdriver, ofw_iicbus) for runtime linking to resolve
all the symbols. With ofw_iicbus and iicbus in separate modules, drivers
would need to declare a MODULE_DEPEND() on both, because symbol lookup is
non-recursive through the dependency chain. Requiring a driver to have
MODULE_DEPENDS() on both amounts to requiring the drivers to understand the
kobj inheritence details of how ofw_iicbus is implemented, which seems like
something they shouldn't have to know (and could even change some day).
Also, this is somewhat analogous to how the drivers get built when compiled
into the kernel. You don't have to ask for ofw_iicbus separately, it just
gets built in along with iicbus when option FDT is in effect.
A super-set of the functionality of jedec_ts(4). jedec_dimm(4) reports asset
information (Part Number, Serial Number) encoded in the "Serial Presence
Detect" (SPD) data on JEDEC DDR3 and DDR4 DIMMs. It also calculates and
reports the memory capacity of the DIMM, in megabytes. If the DIMM includes
a "Thermal Sensor On DIMM" (TSOD), the temperature is also reported.
Reviewed by: cem
MFC after: 1 week
Relnotes: yes
Sponsored by: Panasas
Differential Revision: https://reviews.freebsd.org/D14392
Discussed with: avg, cem
Tested by: avg, cem (previous version, no semantic changes)
- 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).
Add ACPI part for ig4 driver to make it work on Intel BayTrail SoC where
ig4 device is available only through ACPI
Reviewed by: avg
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D8742
Summary:
The hardware does not expose a classic SMBus interface.
Instead it has a lower level interface that can express a far richer
I2C protocol than what smbus offers. However, the interface does not
provide a way to explicitly generate the I2C stop and start conditions.
It's only possible to request that the stop condition is generated
after transferring the next byte in either direction. So, at least
one data byte must always be transferred.
Thus, some I2C sequences are impossible to generate, e.g., an equivalent
of smbus quick command (<start>-<slave addr>-<r/w bit>-<stop>).
At the same time isl(4) and cyapa(4) are moved to iicbus and now they use
iicbus_transfer for communication. Previously they used smbus_trans()
interface that is not defined by the SMBus protocol and was implemented
only by ig4(4). In fact, that interface was impossible to implement
for the typical SMBus controllers like intpm(4) or ichsmb(4) where
a type of the SMBus command must be programmed.
The plan is to remove smbus_trans() and all its uses.
As an aside, the smbus_trans() method deviates from the standard,
but perhaps backwards, FreeBSD convention of using 8-bit slave
addresses (shifted by 1 bit to the left). The method expects
7-bit addresses.
There is a user facing consequence of this change.
A user must now provide device hints for isl and cyapa that specify an iicbus to use
and a slave address on it.
On Chromebook hardware where isl and cyapa devices are commonly found
it is also possible to use a new chromebook_platform(4) driver that
automatically configures isl and cyapa devices. There is no need to
provide the device hints in that case,
Right now smbus(4) driver tries to discover all slaves on the bus.
That is very dangerous. Fortunately, the probing code uses smbus_trans()
to do its job, so it is really enabled for ig4 only.
The plan is to remove that auto-probing code and smbus_trans().
Tested by: grembo, Matthias Apitz <guru@unixarea.de> (w/o
chromebook_platform)
Discussed with: grembo, imp
Reviewed by: wblock (docs)
MFC after: 1 month
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D8172
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
ismt(4) supports the SMBus Message Transport controller found on Intel
C2000 series (Avoton) and S1200 series (Briarwood) Atom SoCs.
Sponsored by: Intel
Use MACHINE_CPUARCH in preference to MACHINE_ARCH. The former is the
source code location of the machine, the latter the binary output. In
general, we want to use MACHINE_CPUARCH instead of MACHINE_ARCH unless
we're tesitng for a specific target. The isn't even moot for
i386/amd64 where there's momemntum towards a MACHINE_CPUARCH == x86,
although a specific cleanup for that likely would be needed...
around to force the IO port to a fixed address. They were only turned
on in the module build and were present since the original import. This
breaks soft power-off on the Asus A7V since it reprograms the SMBus base
address to a different one than the BIOS expects. A similar issue was
found in the alpm(4) module build.
PR: kern/113986, i386/97468
MFC after: 3 days
Approved by: re
drivers I started quite some time before.
Retire the old i386-only pcf driver, and activate the new general
driver that has been sitting in the tree already for quite some
time.
Build the i2c modules for sparc64 architectures as well (where I've
been developing all this on).
