all the chips in the NXP PCA212x and PCA/PCF85xx series. In addition to
supporting more chips, this driver uses the countdown timer on the chips as
a fractional seconds counter, giving it a resolution of about 15 milliseconds.
Usually it is sufficient to use iicbus_transfer_excl(), or one of the
higher-level convenience functions that use it, to reserve the bus for the
duration of each register access. Occasionally it is important that a
series of accesses or read-modify-write operations must be done without any
other intervening access to the device, to prevent corrupting state.
Without support for nested request/release, slave device drivers would have
to stop using high-level convenience functions and resort to working with
arrays of iic_msg structs just for a few operations (often involving
one-time device setup or infrequent configuration changes).
The changes here appear large from a glance at the diff, but in fact they're
nearly trivial, and the large diff is because of changes in indentation and
the re-wrapping of comments caused by that. One notable change is that
iicbus_release_bus() now ignores the IICBUS_CALLBACK(IIC_RELEASE_BUS) return
value. The old error handling left the bus in a kind of limbo state where
it was still owned at the iicbus layer, but drivers rarely check the return
of the release call, and it's unclear what they would do to recover from an
error return anyway. No existing low-level drivers return any kind of error
from IIC_RELEASE_BUS except one EINVAL for "you don't own the bus", to which
the right response is probably to carry on with the process of releasing the
reference to the bus anyway.
on i2c devices, where the "register" can be any length.
Many (perhaps most) common i2c devices are organized as a collection of
(usually 1-byte-wide) registers, and are accessed by first writing a 1-byte
register index/offset number, then by reading or writing the data.
Generally there is an auto-increment feature so the when multiple bytes
are read or written, multiple contiguous registers are accessed.
Most existing slave device drivers allocate an array of iic_msg structures,
fill in all the transfer info, and invoke iicbus_transfer(). These new
functions commonize all that and reduce register access to a simple call
with a few arguments.
similar to "if (ticks > localvar+interval) {localvar=ticks; ...}" where
localvar is initialized to zero. Ticks is initialized to a negative value
since r278230, and that leads to these if statements never being true.
which is able to manipulate the clock and data lines directly.
When an i2c bus is hung by a slave device stuck in the middle of a
transaction that didn't complete properly, this function manipulates the
clock and data lines in a sequence known to reliably reset slave devices.
The most common cause of a hung i2c bus is a system reboot in the middle of
an i2c transfer (so it doesnt' happen often, but now there is a way other
than power cycling to recover from it).
nostop option is set, if a start was issued.
The nostop option doesn't mean "never issue a stop" it means "only issue
a stop after the last in a series of transfers". If the transfer ends
due to error, then that was the last transfer in the series, and a stop
is required.
Before this change, any error during a transfer when nostop is set would
effectively hang the bus, because sc->started would never get cleared,
and that caused all future calls to iicbus_start() to return an error
because it looked like the bus was already active. (Unrelated errors in
handling the nostop option, to be addressed separately, could lead to
this bus hang condition even on busses that don't set the nostop option.)
being overwritten, they are set only bits (cleared by hardware).
Disable the Acknowledge of the controller slave address. The slave mode is
not supported.
Make sure the interrupt flag bit is being cleared as recommended, add a
delay() _after_ clear the interrupt bit.
Sponsored by: Rubicon Communications, LLC (Netgate)
The constant was set to the correct value in r308242.
While there, fix iicsmb_bread() to not use a value of an out parameter
'count'.
MFC after: 3 weeks
X-MFC after: r308242
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
Previously the driver used more low level operations like iicbus_start
and iicbus_write. The problem is that those operations are not
implemented by iicbus(4) and the calls were effectively routed to
a driver to which the bus is attached.
But not all of the controllers implement such low level operations
while all of the drivers are expected to have iicbus_transfer.
While there fix incorrect implementation of iicsmb_bwrite and iicsmb_bread.
The former should send a byte count before the actual bytes, while the
latter should first receive the byte count and then receive the bytes.
I have tested only these commands:
- quick (r/w)
- send byte
- receive byte
- read byte
- write byte
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D8170
'compat' can never be NULL, because the compatible check loop ends when
compat->ocd_str is NULL. This causes ds1307 to attach to any unclaimed i2c
device.
- Read interrupt properties at bus enumeration time and store
it into global mapping table.
- At bus_activate_resource() time, given mapping entry is resolved and
connected to real interrupt source. A copy of mapping entry is attached
to given resource.
- At bus_setup_intr() time, mapping entry stored in resource is used
for delivery of requested interrupt configuration.
- For MSI/MSIX interrupts, mapping entry is created within
pci_alloc_msi()/pci_alloc_msix() call.
- For legacy PCI interrupts, mapping entry must be created within
pcib_route_interrupt() by pcib driver itself.
Reviewed by: nwhitehorn, andrew
Differential Revision: https://reviews.freebsd.org/D7493
In some cases, the driver must handle given properties located in
specific OF subnode. Instead of creating duplicate set of function, add
'node' as argument to existing functions, defaulting it to device OF node.
MFC after: 3 weeks
Pressing the PEK (power enable key) will shutdown the board.
Some events are reported to devd via system "PMU" and subsystem
"Battery", "AC" and "USB" such as connected/disconnected.
Some sensors values (power source voltage/current) are reported via
sysctl (dev.axp209_pmu.X.)
It also expose a gpioc node usable in kernel and userland. Only 3 of
the 4 GPIO are exposed (The GPIO3 is different and mostly unused on
boards). Most popular boards uses GPIO1 as a sense pin for OTG power.
Add a dtsi file that adds gpio-controller capability to the device as
upstream doesn't defined it and include it in our custom DTS.
Reviewed by: jmcneill
Approved by: cognet (mentor)
Differential Revision: https://reviews.freebsd.org/D6135
After r285994, sysctl(8) was fixed to use 273.15 instead of 273.20 as 0C
reference and as result, the temperature read in sysctl(8) now exibits a
+0.1C difference.
This commit fix the kernel references to match the reference value used in
sysctl(8) after r285994.
Sponsored by: Rubicon Communications (Netgate)
Also check the return value of copyin(9) to prevent unnecessary allocation in the failure case.
Submitted by: ngie
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D5155
This is compatible with the ds1307, but comparing the mcp7941x datasheet vs the
ds1307 code, appears there is one bit placement difference, so that is now
accounted for.
Relnotes: yes
Most calls to bus_alloc_resource() use "anywhere" as the range, with a given
count. Migrate these to use the new bus_alloc_resource_anywhere() API.
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D5370
support for the i2c, mmc, and gmac clocks. Further clocks can be added as
needed.
Submitted by: Emmanuel Vadot <manu@bidouilliste.com>
Reviewed by: jmcneill
Differential Revision: https://reviews.freebsd.org/D5339
Marvell twsi part, however uses different register locations, as such split
the existing driver into Marvell and Allwinner attachments.
While here clean a few style issues.
Submitted by: Emmanuel Vadot <manu@bidouilliste.com>
Differential Revision: https://reviews.freebsd.org/D4846
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)
