The FDT bindings for eeprom parts don't include any metadata about the
device other than the part name encoded in the compatible property.
Instead, a driver is required to have a compiled-in table of information
about the various parts (page size, device capacity, addressing scheme). So
much for FDT being an abstract description of hardware characteristics, huh?
In addition to the FDT-specific changes, this also switches to using the
newer iicbus_transfer_excl() mechanism which holds bus ownership for the
duration of the transfer. Previously this code held the bus across all
the transfers needed to complete the user's IO request, which could be
up to 128KB of data which might occupy the bus for 10-20 seconds. Now the
bus will be released and re-aquired between every page-sized (8-256 byte)
transfer, making this driver a much nicer citizen on the i2c bus.
The hint-based configuration mechanism is still in place for non-FDT systems.
Michal Meloun contributed some of the code for these changes.
while holding exclusive ownership of the bus. This is the routine most
slave drivers should use unless they have a need to acquire and hold the
bus across a series of related operations that involves multiple transfers.
If the bus is detached and deleted by a call to device_delete_child() or
device_delete_children() on a device higher in the tree, I²C children
were already detached and deleted. So the device_t pointer stored in sc
points to freed memory: we must not try to delete it again.
By using device_delete_children(), we let subr_bus.c figure out if there
are children to take care of.
While here, make sure iicbus_detach() and iicoc_detach() call
device_delete_children() too, to be safe.
Reviewed by: jhb, imp
Approved by: jhb, imp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3926
these functions are thin wrappers around calling the hardware-layer driver,
but some of them do sanity checks and return an error. Since the hardware
layer can only return IIC_Exxxxx status values, the iicbus helper functions
must also adhere to that, so that drivers at higher layers can assume that
any non-zero status value is an IIC_Exxxx value that provides details about
what happened at the hardware layer (sometimes those details are important
for certain slave drivers).
errno values that are at least vaguely equivelent. Also add a new status
value, IIC_ERESOURCE, to indicate a failure to acquire memory or other
required resources to complete a transaction.
The IIC_Exxxxxx values are supposed to communicate low-level details of the
i2c transaction status between the lowest-layer hardware driver and
higher-layer bus protocol and device drivers for slave devices on the bus.
Most of those slave drivers just return all status values from the lower
layers directly to their callers, resulting in crazy error reporting from a
user's point of view (things like timeouts being reported as "no such
process"). Now there's a helper function to make it easier to start
cleaning up all those drivers.
Make it clearer what each one means in the comments that define them.
IIC_BUSBSY was used in many places to mean two different things, either
"someone else has reserved the bus so you have to wait until they're done"
or "the signal level on the bus was not in the state I expected before/after
issuing some command".
Now IIC_BUSERR is used consistantly to refer to protocol/signaling errors,
and IIC_BUSBSY refers to ownership/reservation of the bus.
perform a stop operation on the bus if there was an error, otherwise the
bus will remain hung forever. Consistantly use 'if (error != 0)' style in
the function.
bus_alloc_resource(), bus_release_resource() and bus_set_resource()
(bus_generic_rl_alloc_resource(), bus_generic_rl_release_resource() and
bus_generic_rl_set_resource() respectively).
Do not print the resources for nomatch devices.
Use the inherited method for bus_get_resource_list() on ofw_iicbus.c.
Submitted by: jhb and Michal Meloun (D2033)
controllers.
Call iicbus_transfer() from the device context and not from the iicbus
context.
I am committing a slightly different patch, so if something break, it is
probably my fault.
PR: 199496
Submitted by: Juraj Lutter <otis@sk.FreeBSD.org>
--Allow multiple open iic fds by storing addressing state in cdevpriv
--Fix, as much as possible, the baked-in race conditions in the iic
ioctl interface by requesting bus ownership on I2CSTART, releasing it on
I2CSTOP/I2CRSTCARD, and requiring bus ownership by the current cdevpriv
to use the I/O ioctls
--Reduce internal iic buffer size and remove 1K read/write limit by
iteratively calling iicbus_read/iicbus_write
--Eliminate dynamic allocation in I2CWRITE/I2CREAD
--Move handling of I2CRDWR to separate function and improve error handling
--Add new I2CSADDR ioctl to store address in current cdevpriv so that
I2CSTART is not needed for read(2)/write(2) to work
--Redesign iicbus_request_bus() and iicbus_release_bus():
--iicbus_request_bus() no longer falls through if the bus is already
owned by the requesting device. Multiple threads on the same device may
want exclusive access. Also, iicbus_release_bus() was never
device-recursive anyway.
--Previously, if IICBUS_CALLBACK failed in iicbus_release_bus(), but
the following iicbus_poll() call succeeded, IICBUS_CALLBACK would not be
issued again
--Do not hold iicbus mtx during IICBUS_CALLBACK call. There are
several drivers that may sleep in IICBUS_CALLBACK, if IIC_WAIT is passed.
--Do not loop in iicbus_request_bus if IICBUS_CALLBACK returns
EWOULDBLOCK; instead pass that to the caller so that it can retry if so
desired.
Differential Revision: https://reviews.freebsd.org/D2140
Reviewed by: imp, jhb, loos
Approved by: kib (mentor)
Many thanks to ian who gently provided me the DS1307 breakout board.
Tested on: Raspberry pi
Differential Revision: https://reviews.freebsd.org/D2022
Reviewed by: rpaulo
I2C real-time clock (RTC).
The DS3231 has an integrated temperature-compensated crystal oscillator
(TXCO) and crystal.
DS3231 has a temperature sensor, an independent 32kHz output (which can be
turned on and off by the driver) and another output that can be used as
interrupt for alarms or as a second square-wave output, which frequency and
operation mode can be set by driver sysctl(8) knobs.
Differential Revision: https://reviews.freebsd.org/D1016
Reviewed by: ian, rpaulo
Tested on: Raspberry pi model B
The current support for controlling i2c bus speed is an inconsistant mess.
There are 4 symbolic speed values defined, UNKNOWN, SLOW, FAST, FASTEST.
It seems to be universally assumed that SLOW means the standard 100KHz
rate from the original spec. Nothing ever calls iicbus_reset() with a
speed of FAST, although some drivers would treat it as the 400KHz standard
speed. Mostly iicbus_reset() is called with the speed set to UNKNOWN or
FASTEST, and there's really no telling what any individual driver will do
with those.
The speed of an i2c bus is limited by the speed of the slowest device on
the bus. This means that generally the bus speed needs to be configured
based on the board/system and the components within it. Historically for
i2c we've configured with device hints. Newer systems use FDT data and it
documents a clock-frequency property for i2c busses. Hobbyists and
developers are likely to want on the fly changes. These changes provide
all 3 methods, but do not require any existing drivers to change to use
the new facilities.
This adds an iicbus method, iicbus_get_frequency(dev, speed) that gets the
frequency for the requested symbolic speed. If the symbolic speed is SLOW
or if there is no speed configured for the bus, the returned value is
100KHz, always. Otherwise, if bus speed is configured by hints, fdt,
tunable, or sysctl, that speed is returned. It also adds a helper
function, iicbus_init_frequency() that any bus driver subclassed from
iicbus can initialize the frequency from some other source of info.
Initial driver implementations are provided for Freescale and TI.
Differential Revision: https://reviews.freebsd.org/D1174
PR: 195009
transfers to be default. It simplifies porting code which assumes
such settings.
Discussed with: avg, llos, nwhitehorn
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
For compatibility, 'device windtunnel' is still supported, but one should use
'device adm1030' instead, and this has been updated in GENERIC and NOTES.
There's a very remote, but possible, chance that the integer part read will
fail, but the fraction read succeeds, at which point the reported temperature is
invalid.
Reported by: Matthew Rezny
MFC after: 3 weeks
This driver supports the low and high precision models (9 and 11 bits) and
it will auto-detect the both variants.
The driver expose the temperature registers (actual temperature, shutdown
and hysteresys temperature) and also the configuration register.
It was tested on FDT systems: RPi, BBB and on non-FDT systems: AR71xx, with
both, hardware i2c controllers (when available) and gpioiic(4).
This provides a simple and cheap way for verifying the i2c bus on embedded
systems.
This change makes ofw_iicbus attach to iicbb(4) controllers in addition to
the already supported i2c host bridges (iichb).
On iicbb(4) allow the direct access of the OFW parent node by its children,
so they can be directly attached to iicbb(4) node on the DTS without the
need of describing the i2c bus.
Approved by: adrian (mentor, implicit)
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
extremely outdated, and I doubt that it was ever used for ifnet drivers.
It was used for AF_INET sockets in pre-FreeBSD time.
Approved by: re (hrs)
Sponsored by: Nginx, Inc.
doesn't automatically clear when VDD rises above Vlow again and needs to be
cleared manually. However, apparently this needs all of the time registers
to be set, i.e. pcf8563_settime(), and not just PCF8563_R_SECOND in order
for PCF8563_R_SECOND_VL to stick. Thus, we just issue a warning during
pcf8563_attach() rather than failing with ENXIO in case it is set.
MFC after: 3 days
