Now that the upper layers all go through a layer to tie into these
information functions that translates an sbuf into char * and len. The
current interface suffers issues of what to do in cases of truncation,
etc. Instead, migrate all these functions to using struct sbuf and these
issues go away. The caller is also in charge of any memory allocation
and/or expansion that's needed during this process.
Create a bus_generic_child_{pnpinfo,location} and make it default. It
just returns success. This is for those busses that have no information
for these items. Migrate the now-empty routines to using this as
appropriate.
Document these new interfaces with man pages, and oversight from before.
Reviewed by: jhb, bcr
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D29937
This is an import of the Google Summer of Code 2018 project completed by
Christian Kramer (and, sadly, ignored by us for two years now). The goals
stated for that project were:
FreeBSD already has support for interrupts implemented in the GPIO
controller drivers of several SoCs, but there are no interfaces to take
advantage of them out of user space yet. The goal of this work is to
implement such an interface by providing descriptors which integrate
with the common I/O system calls and multiplexing mechanisms.
The initial imported code supports the following functionality:
- A kernel driver that provides an interface to the user space; the
existing gpioc(4) driver was enhanced with this functionality.
- Implement support for the most common I/O system calls / multiplexing
mechanisms:
- read() Places the pin number on which the interrupt occurred in the
buffer. Blocking and non-blocking behaviour supported.
- poll()/select()
- kqueue()
- signal driven I/O. Posting SIGIO when the O_ASYNC was set.
- Many-to-many relationship between pins and file descriptors.
- A file descriptor can monitor several GPIO pins.
- A GPIO pin can be monitored by multiple file descriptors.
- Integration with gpioctl and libgpio.
I added some fixes (mostly to locking) and feature enhancements on top of
the original gsoc code. The feature ehancements allow the user to choose
between detailed and summary event reporting. Detailed reporting provides
a record describing each pin change event. Summary reporting provides the
time of the first and last change of each pin, and a count of how many times
it changed state since the last read(2) call. Another enhancement allows
the recording of multiple state change events on multiple pins between each
call to read(2) (the original code would track only a single event at a time).
The phabricator review for these changes timed out without approval, but I
cite it below anyway, because the review contains a series of diffs that
show how I evolved the code from its original state in Christian's github
repo for the gsoc project to what is being commited here. (In effect,
the phab review extends the VC history back to the original code.)
Submitted by: Christian Kramer
Obtained from: https://github.com/ckraemer/freebsd/tree/gsoc2018
Differential Revision: https://reviews.freebsd.org/D27398
It's interesting that similar messages from gpiobus_acquire_pin never
had any prefix while gpiobus_release_pin messages were prefixed with
"gpiobus_acquire_pin".
Anyway, the prefix is not that useful and can be deduced from context.
MFC after: 2 weeks
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.
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.
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.
"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
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.
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
- 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
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.
Add gpiobus_release_pin as a counterpart for gpiobus_map_pin. Without it
it's impossible to properly release pin so if kernel module is reloaded
it can't re-use pins again
Add new function gpio_alloc_intr_resource(), which allows an allocation
of interrupt resource associated to given gpio pin. It also allows to
specify interrupt configuration.
Note: This functionality is dependent on INTRNG, and must be
implemented in each GPIO controller.
This simplifies checking for default resource range for bus_alloc_resource(),
and improves readability.
This is part of, and related to, the migration of rman_res_t from u_long to
uintmax_t.
Discussed with: jhb
Suggested by: marcel
Summary:
Migrate to using the semi-opaque type rman_res_t to specify rman resources. For
now, this is still compatible with u_long.
This is step one in migrating rman to use uintmax_t for resources instead of
u_long.
Going forward, this could feasibly be used to specify architecture-specific
definitions of resource ranges, rather than baking a specific integer type into
the API.
This change has been broken out to facilitate MFC'ing drivers back to 10 without
breaking ABI.
Reviewed By: jhb
Sponsored by: Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D5075
- Detach the gpiobus and the gpioc devices from the GPIO controller.
- Fix the leak of gpiobus IRQ rman(9) region descriptor.
- Fix the leak of child ivars and IRQ resource list.
While here return NULL (instead of 0) for a device_t that fails to allocate
the ivar memory.
Tested with gpiobus built as a module.
Sponsored by: Rubicon Communications (Netgate)
When a gpiobus child is added, use its name to identify the mapped pin
names.
Make the respective changes to libgpio.
Add a new '-n' flag to gpioctl(8) to set the pin name.
Differential Revision: https://reviews.freebsd.org/D2002
Reviewed by: rpaulo
Requested by: many
This prints a warning when your system have a hinted child or a FDT child
node for which you don't have a matching driver:
gpiobus0: <unknown device> at pin(s) 24 irq 24
This new function can be used by other drivers to reserve the use of GPIO
pins.
Anyway, the use of ofw_gpiobus_parse_gpios() is preferred when possible.
Requested by: Michal Meloun
This is the general support to allow the use of GPIO pins as interrupt
sources for direct gpiobus children.
The use of GPIO pins as generic interrupt sources (for an ethernet driver
for example) will only be possible when arm/intrng is complete. Then, most
of this code will need to be rewritten, but it works for now, is better
than what we have and will allow further developments.
Tested on: ar71xx (RSPRO), am335x (BBB), bcm2835 (Raspberry pi)
Differential Revision: https://reviews.freebsd.org/D999
Reviewed by: rpaulo
hold the gpiobus lock between the gpio calls.
gpiobus_acquire_lock() now accepts a third parameter which tells gpiobus
what to do when the bus is already busy.
When GPIOBUS_WAIT wait is used, the calling thread will be put to sleep
until the bus became free.
With GPIOBUS_DONTWAIT the calling thread will receive EWOULDBLOCK right
away and then it can act upon.
This fixes the gpioiic(4) locking issues that arises when doing multiple
concurrent access on the bus.
sys/systm.h must always come after sys/param.h.
Remove sys/types.h which should never be included together with sys/param.h.
Add sys/malloc.h for correctness even if it seems to don't be needed.
Remove more unused headers found by unusedinc (from bde@) and tested with a
universe build.
Reported by: bde
describe GPIO bindings in the system.
Move the GPIOBUS lock macros to gpiobusvar.h as they are now shared between
the OFW and the non OFW versions of GPIO bus.
Export gpiobus_print_pins() so it can also be used on the OFW GPIO bus.
Approved by: adrian (mentor, implicit)
it can be overriden by its OFW/FDT version.
Give a chance for GPIO devices that implement the device_identify method to
attach.
Approved by: adrian (mentor)
one. Interestingly, these are actually the default for quite some time
(bus_generic_driver_added(9) since r52045 and bus_generic_print_child(9)
since r52045) but even recently added device drivers do this unnecessarily.
Discussed with: jhb, marcel
- While at it, use DEVMETHOD_END.
Discussed with: jhb
- Also while at it, use __FBSDID.
