At the end of a read cycle, set the gpio pin to INPUT rather than OUTPUT.
The state of the single-wire "bus" when idle should be high; setting the
pin to input allows the external pullup to pull the line high. Setting it
to output (and leaving it driving low) was leading a good read cycle followed
by one that would fail, and it just continued like that forever, effectively
reading the sensor once every 10 seconds instead of 5.
In the attach function, do an initial read from the device before registering
the sysctls for accessing the last-read values, to prevent reading spurious
values for the first 5 seconds after the driver attaches.
Do a callout_drain() in the detach function to prevent crashes after
unloading the module.
of gpio devices by using kenv to add hints for a new device and then do
'devctl rescan gpiobus4' to make the new device(s) attach.
It's not particularly easy to detect whether the 'at' hint has been deleted
for a child device that's currently attached, so this doesn't handle that.
But the user can use devctl commands to manually detach an existing device.
Uses two GPIO pins as MDC (clock) and MDIO (bidirectional I/O), relies
on mii_bitbang.
Tested on SG-3200 where the PHY for one of the ports is wired independently
of the SoC MDIO bus.
Sponsored by: Rubicon Communications, LLC (Netgate)
struct gpio_pin. It turns out these two sets of flags are completely
unrelated to each other.
Also, update the comment for GPIO_ACTIVE_LOW to reflect the fact that it
does get set, somewhat unobviously, by code that parses FDT data. The bits
from the FDT cell containing flags are just copied to gpiobus_pin.flags, so
there's never any obvious reference to the symbol GPIO_ACTIVE_LOW being
stored into the flags field.
FDT bindings document for gpio-i2c devices.
Using the gpio_pin_* functions to acquire/release/manipulate gpio pins
removes the constraint that both gpio pins must belong to the same gpio
controller/bank, and that the gpioiic instance must be a child of gpiobus.
Removing those constraints allows the driver to be fully compatible with
the modern dts bindings for a gpio bitbanged i2c bus.
For hinted attachment, the two gpio pins still must be on the same gpiobus,
and the device instance must be a child of that bus. This preserves
compatibility for existing installations that have use gpioiic(4) with hints.
that they can be used by drivers on non-FDT-configured systems. Only the
functions related to acquiring pins by parsing FDT data remain in
ofw_gpiobus. Also, add two new functions for acquiring gpio pins based on
child device_t and index, or on the bus device_t and pin number. And
finally, defer reserving pins for gpiobus children until they acquire the
pin, rather than reserving them as soon as the child is added (before it's
even known whether the child will attach).
This will allow drivers configured with hints (or any other mechanism) to
use the same code as drivers configured via FDT data. Until now, a hinted
driver and an FDT driver had to be two completely different sets of code,
because hinted drivers could only use gpiobus calls to manipulate pins,
while fdt-configured drivers could not use that API (due to not always being
children of the bus that owns the pins) and had to use the newer
gpio_pin_xxxx() functions. Now drivers can be written in the more
traditional form, where most of the code is shared and only the resource
acquisition code at attachment time changes.
As part of my journey to make it easy to determine what's relying on tty
bits, remove a couple more. Some of these just outright didn't need it,
while others did rely on <sys/tty.h> pollution for mutex headers.
in ofw_gpiobus_probe() return BUS_PROBE_DEFAULT rather than 0; we are not
the only possible driver to handle this device, we're just slightly better
than the base gpiobus (which probes at BUS_PROBE_GENERIC).
In the time since this code was first written, the gpio controller bindings
aquired the concept of a "hog" node which could be used to preset one or
more gpio pins as input or output at a specified level. This change doesn't
fully implement the hogging concept, it just filters out hog nodes when
instantiating child devices by scanning for child nodes in the fdt data.
The whole concept of having child nodes under the controller node is not
supported by the standard bindings, and appears to be a freebsd extension,
probably left over from the days when we had no support for cross-tree
phandle references in the fdt data.
Some controllers cannot preset future output value while the pin is in
input mode. This adds a fallback for those controllers. The new code
assumes that a controller reports an error in that case.
For example, all hardware supported by nctgpio behaves in that way.
This is a temporary measure. In the future we will use
GPIO_PIN_PRESET_LOW / GPIO_PIN_PRESET_HIGH to preset the output either
in hardware, if supported, or in software (e.g., in
gpiobus_pin_setflags).
While here, I extracted common functionality of gpioiic_set{sda,scl} and
gpioiic_get{sda,scl} to gpioiic_setpin and gpioiic_getpin respectively.
MFC after: 2 weeks
"pin_list" allows to specify child pins as a list of pin numbers.
Existing hint "pins" serves the same purpose but with a 32-bit wide bit
mask. One problem with that is that a controller can have more than 32
pins. One example is amdgpio. Also, a list of numbers is a little bit
more human friendly than a matching bit mask. As a side note, it seems
that in FDT pins are typically specified by their numbers as well.
This commit also adds accessors for instance variables (IVARs) that
define the child pins. My primary goal is to allow a child to be
configured programmatically rather than via hints (assuming that FDT is
not supported on a platform). Also, while a child should not care about
specific pin numbers that are allocated to it, it could be interested in
how many were actually assigned to it.
While there, I removed "flags" instance variable. It was unused.
Reviewed by: mizhka
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20459
This fixes a panic in Espressobin when gpioregulator fails to allocate the
GPIO pin (the GPIO controller is not there).
Sponsored by: Rubicon Communications, LLC (Netgate)
hint.gpioled.%d.state determines the initial state of the LED when the
driver takes control over it:
0 - the LED is off
1 - the LED is on
-1 - the LED is kept as it was
While here, add a module version declaration.
MFC after: 2 weks
Change OF_getencprop_alloc semantics to be combination of malloc and
OF_getencprop and return size of the property, not number of elements
allocated.
For the use cases where number of elements is preferred introduce
OF_getencprop_alloc_multi helper function that copies semantics
of OF_getencprop_alloc prior to this change.
This is to make OF_getencprop_alloc and OF_getencprop_alloc_multi
function signatures consistent with OF_getencprop_alloc and
OF_getencprop_alloc_multi.
Functionality-wise this patch is mostly rename of OF_getencprop_alloc
to OF_getencprop_alloc_multi except two calls in ofw_bus_setup_iinfo
where 1 was used as a block size.
OF_getprop_alloc takes element size argument and returns number of
elements in the property. There are valid use cases for such behavior
but mostly API consumers pass 1 as element size to get string
properties. What API users would expect from OF_getprop_alloc is to be
a combination of malloc + OF_getprop with the same semantic of return
value. This patch modifies API signature to match these expectations.
For the valid use cases with element size != 1 and to reduce
modification scope new OF_getprop_alloc_multi function has been
introduced that behaves the same way OF_getprop_alloc behaved prior to
this patch.
Reviewed by: ian, manu
Differential Revision: https://reviews.freebsd.org/D14850
Add chvgpio(4) driver for Intel Z8xxx SoC family. This product
was formerly known as Cherry Trail but Linux and OpenBSD drivers
refer to it as Cherry View. This driver is derived from OpenBSD
one so the name is kept for alignment with another BSD system.
Submitted by: Tom Jones <tj@enoti.me>
Reviewed by: gonzo, wblock(man page)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D13086
and index. A private function to do exactly that already existed, so this
renames gpio_pin_get_by_ofw_impl() to gpio_pin_get_by_ofw_propidx() and
provides a declaration for it in a public header.
Previously there were functions to get a pin by property name (assuming
there would only be one pin defined for the name), or by index (asuming
the property has the standard name "gpios"). It turns out there are
devicetree bindings that describe properties with names other than "gpios"
which can describe multiple pins. Hence the need to retrieve the Nth item
from a named property.
Uses of mallocarray(9).
The use of mallocarray(9) has rocketed the required swap to build FreeBSD.
This is likely caused by the allocation size attributes which put extra pressure
on the compiler.
Given that most of these checks are superfluous we have to choose better
where to use mallocarray(9). We still have more uses of mallocarray(9) but
hopefully this is enough to bring swap usage to a reasonable level.
Reported by: wosch
PR: 225197
Focus on code where we are doing multiplications within malloc(9). None of
these is likely to overflow, however the change is still useful as some
static checkers can benefit from the allocation attributes we use for
mallocarray.
This initial sweep only covers malloc(9) calls with M_NOWAIT. No good
reason but I started doing the changes before r327796 and at that time it
was convenient to make sure the sorrounding code could handle NULL values.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Sometimes it is necessary to combine several gpio pins into an ad-hoc bus
and manipulate the pins as a group. In such cases manipulating the pins
individualy is not an option, because the value on the "bus" assumes
potentially-invalid intermediate values as each pin is changed in turn. Note
that the "bus" may be something as simple as a bi-color LED where changing
colors requires changing both gpio pins at once, or something as complex as
a bitbanged multiplexed address/data bus connected to a microcontroller.
In addition to the absolute requirement of simultaneously changing the
output values of driven pins, a desirable feature of these new methods is to
provide a higher-performance mechanism for reading and writing multiple
pins, especially from userland where pin-at-a-time access incurs a noticible
syscall time penalty.
These new interfaces are NOT intended to abstract away all the ugly details
of how gpio is implemented on any given platform. In fact, to use these
properly you absolutely must know something about how the gpio hardware is
organized. Typically there are "banks" of gpio pins controlled by registers
which group several pins together. A bank may be as small as 2 pins or as
big as "all the pins on the device, hundreds of them." In the latter case, a
driver might support this interface by allowing access to any 32 adjacent
pins within the overall collection. Or, more likely, any 32 adjacent pins
starting at any multiple of 32. Whatever the hardware restrictions may be,
you would need to understand them to use this interface.
In additional to defining the interfaces, two example implementations are
included here, for imx5/6, and allwinner. These represent the two primary
types of gpio hardware drivers. imx6 has multiple gpio devices, each
implementing a single bank of 32 pins. Allwinner implements a single large
gpio number space from 1-n pins, and the driver internally translates that
linear number space to a bank+pin scheme based on how the pins are grouped
into control registers. The allwinner implementation imposes the restriction
that the first_pin argument to the new functions must always be pin 0 of a
bank.
Differential Revision: https://reviews.freebsd.org/D11810
This patch adds driver for temperature/humidity sensor connected via GPIO.
To compile it into kernel add "device gpioths". To activate driver, use
hints (.at and .pins) for gpiobus. As result it will provide temperature &
humidity values via sysctl.
DHT11 is cheap & popular temperature/humidity sensor used via GPIO on ARM
or MIPS devices like Raspberry Pi or Onion Omega.
Reviewed by: adrian
Approved by: adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D9185
- Do not set input flag when reading value from GPIO pin, it is not
required and for gpioc2(S5 bank) setting both input and output flags
leads to some kind of electric interference (curren drop?) that
causes USB devices to disconnect
- Check pad configuration when attaching device and provide IN/OUT
capabilities only for pads that are configured as GPIO. Do not let
user code to configure or change value of non-GPIO pads. There is
no information for NC bank in intel's datasheet so for now function
check is ignored for pins in it
Reported by: Frank H.
MFC after: 3 days
The gpiobus driver is attached explicitly and generally should be
at the same pass as its parent. Making it use BUS_PAS_BUS ensures
that it attaches immediately after parent adds it (assuming the
parent itself attached at BUS_PAS_BUS and above).
Submitted by: kan
Sponsored by: DARPA, AFRL
Summary:
This implements part of the gpio-poweroff and gpio-restart device tree
bindings. Optional properties are not handled currently. It also currently
only supports level-triggered reset.
Reviewed By: gonzo
Differential Revision: https://reviews.freebsd.org/D8521
- Split driver in two parts: FDT and non-FDT
- Instead of reattach gpioled nodes to GPIO bus use
gpio_pin_get_by_ofw_idx and add ofwbus and simplebus as parrent buses
Reviewed by: loos
Differential Revision: https://reviews.freebsd.org/D8233
Bay Trail has three banks of GPIOs exposed to userland as /dev/gpiocN,
where N is 1, 2, and 3. Pins in each bank are pre-named to match names
on boards schematics: GPIO_S0_SCnn, GPIO_S0_NCnn, and GPIO_S5_nn.
Controller supports edge-triggered and level-triggered interrupts but
current version of the driver does not have interrupts support
Trying to build a MIPS platform that uses INTRNG needs this
for this to work right in gpiobusvar.h :
#ifdef INTRNG
struct intr_map_data_gpio {
struct intr_map_data hdr;
...
};
#endif
- 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
No, this isn't a star trek science joke - sometimes LEDs are wired
up to be active low, so this is needed.
Submitted by: Dan Nelson <dnelson_1901@yahoo.com>
wrap the implementation so that it returns an error if INTRNG support is
not available. It should be possible to write a non-INTRNG implementation
of this function some day. In the meantime, there is code that contains
calls to this function (so the decl is needed), but have runtime checks to
avoid calling it in the non-INTRNG case.
