This is the bulk of GPIO changes for kernel v4.6:
Core changes:
- The gpio_chip is now a *real device*. Until now the gpio chips
were just piggybacking the parent device or (gasp) floating in
space outside of the device model. We now finally make GPIO chips
devices. The gpio_chip will create a gpio_device which contains
a struct device, and this gpio_device struct is kept private.
Anything that needs to be kept private from the rest of the kernel
will gradually be moved over to the gpio_device.
- As a result of making the gpio_device a real device, we have added
resource management, so devm_gpiochip_add_data() will cut down on
overhead and reduce code lines. A huge slew of patches convert
almost all drivers in the subsystem to use this.
- Building on making the GPIO a real device, we add the first step
of a new userspace ABI: the GPIO character device. We take small
steps here, so we first add a pure *information* ABI and the tool
"lsgpio" that will list all GPIO devices on the system and all
lines on these devices. We can now discover GPIOs properly from
userspace. We still have not come up with a way to actually *use*
GPIOs from userspace.
- To encourage people to use the character device for the future,
we have it always-enabled when using GPIO. The old sysfs ABI is
still opt-in (and can be used in parallel), but is marked as
deprecated. We will keep it around for the foreseeable future,
but it will not be extended to cover ever more use cases.
Cleanup:
- Bjorn Helgaas removed a whole slew of per-architecture <asm/gpio.h>
includes. This dates back to when GPIO was an opt-in feature and
no shared library even existed: just a header file with proper
prototypes was provided and all semantics were up to the arch to
implement. These patches make the GPIO chip even more a proper
device and cleans out leftovers of the old in-kernel API here
and there. Still some cruft is left but it's very little now.
- There is still some clamping of return values for .get() going
on, but we now return sane values in the vast majority of drivers
and the errorpath is sanitized. Some patches for powerpc, blackfin
and unicore still drop in.
- We continue to switch the ARM, MIPS, blackfin, m68k local GPIO
implementations to use gpiochip_add_data() and cut down on code
lines.
- MPC8xxx is converted to use the generic GPIO helpers.
- ATH79 is converted to use the generic GPIO helpers.
New drivers:
- WinSystems WS16C48
- Acces 104-DIO-48E
- F81866 (a F7188x variant)
- Qoric (a MPC8xxx variant)
- TS-4800
- SPI serializers (pisosr): simple 74xx shift registers connected
to SPI to obtain a dirt-cheap output-only GPIO expander.
- Texas Instruments TPIC2810
- Texas Instruments TPS65218
- Texas Instruments TPS65912
- X-Gene (ARM64) standby GPIO controller
Revert "Share upstreaming patches"
This reverts commit a101ad945113be3d7f283a181810d76897f0a0d6.
1 file changed
