![]() CORE: - Fix the semantics of raw GPIO to actually be raw. No inversion semantics as before, but also no open draining, and allow the raw operations to affect lines used for interrupts as the caller supposedly knows what they are doing if they are getting the big hammer. - Rewrote the __inner_function() notation calls to names that make more sense. I just find this kind of code disturbing. - Drop the .irq_base() field from the gpiochip since now all IRQs are mapped dynamically. This is nice. - Support for .get_multiple() in the core driver API. This allows us to read several GPIO lines with a single register read. This has high value for some usecases: it can be used to create oscilloscopes and signal analyzers and other things that rely on reading several lines at exactly the same instant. Also a generally nice optimization. This uses the new assign_bit() macro from the bitops lib that was ACKed by Andrew Morton and is implemented for two drivers, one of them being the generic MMIO driver so everyone using that will be able to benefit from this. - Do not allow requests of Open Drain and Open Source setting of a GPIO line simultaneously. If the hardware actually supports enabling both at the same time the electrical result would be disastrous. - A new interrupt chip core helper. This will be helpful to deal with "banked" GPIOs, which means GPIO controllers with several logical blocks of GPIO inside them. This is several gpiochips per device in the device model, in contrast to the case when there is a 1-to-1 relationship between a device and a gpiochip. NEW DRIVERS: - Maxim MAX3191x industrial serializer, a very interesting piece of professional I/O hardware. - Uniphier GPIO driver. This is the GPIO block from the recent Socionext (ex Fujitsu and Panasonic) platform. - Tegra 186 driver. This is based on the new banked GPIO infrastructure. OTHER IMPROVEMENTS: - Some documentation improvements. - Wakeup support for the DesignWare DWAPB GPIO controller. - Reset line support on the DesignWare DWAPB GPIO controller. - Several non-critical bug fixes and improvements for the Broadcom BRCMSTB driver. - Misc non-critical bug fixes like exotic errorpaths, removal of dead code etc. - Explicit comments on fall-through switch() statements. -----BEGIN PGP SIGNATURE----- iQIcBAABAgAGBQJaCvGiAAoJEEEQszewGV1z+oAQAJUpdPH/msdgHDuXSuBcbuFq NObQdkRiz1hez4vJOT+kbgES6ay57MArnbmM/xRdy+37lKrmkP+yfZe4UUruQhhW f2GVlwBbUp9tIzNliS8IYWO0tj+BTYyg1MQx0C0nE1zMZqVZk44EDa9SO6esRaFJ SLc2BpO3oJCQRaObe0+KTHIJV0dK3vQh4QXSzL+cM5u7P67Jq+wv4xdLVVScwbJB 4jgwVER3Ah0E1jHclIG2PxI1rbYKwlOBumafOTUlq5fmfC3tULVPJEm9FXcdaBLJ KAmtxX4yi+SgUccYFsmK+fNNLVQiAjmkhJCl6kxVOrxYqamrG100YST4Iew3sakM /iQ3lpup5L6eJ/dndfgE207OqRFhvAzNRxORv1p/wJIRLmV1/QehCX8GYOcDumXY MySRcEeUeZPfBHcnjIDRP6y/XOg8zBKso7GL+feRgLZUJZlNQZqokdC95TY9S5nm QLK+sU367o41tomyv5TP3y1DDsym6+ZdpuOUh73znxuz2x/x+FfTfwM2J0r8Ussm GQTfAojeBI9aSOZ2mvgRI1XxSprXqO3FFFWBwrQ6RS9rBceLF1o2ySKC2gI0FG5d 6GBkARcN5RyyNtYkH923pyrqz/FZJc6ZkrsUTGmERM5HGuWwczcditqwYRhbHwl8 pIlmX4y0AYh6FFVoIcQE =8Mon -----END PGP SIGNATURE----- Merge tag 'gpio-v4.15-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for the v4.15 kernel cycle: Core: - Fix the semantics of raw GPIO to actually be raw. No inversion semantics as before, but also no open draining, and allow the raw operations to affect lines used for interrupts as the caller supposedly knows what they are doing if they are getting the big hammer. - Rewrote the __inner_function() notation calls to names that make more sense. I just find this kind of code disturbing. - Drop the .irq_base() field from the gpiochip since now all IRQs are mapped dynamically. This is nice. - Support for .get_multiple() in the core driver API. This allows us to read several GPIO lines with a single register read. This has high value for some usecases: it can be used to create oscilloscopes and signal analyzers and other things that rely on reading several lines at exactly the same instant. Also a generally nice optimization. This uses the new assign_bit() macro from the bitops lib that was ACKed by Andrew Morton and is implemented for two drivers, one of them being the generic MMIO driver so everyone using that will be able to benefit from this. - Do not allow requests of Open Drain and Open Source setting of a GPIO line simultaneously. If the hardware actually supports enabling both at the same time the electrical result would be disastrous. - A new interrupt chip core helper. This will be helpful to deal with "banked" GPIOs, which means GPIO controllers with several logical blocks of GPIO inside them. This is several gpiochips per device in the device model, in contrast to the case when there is a 1-to-1 relationship between a device and a gpiochip. New drivers: - Maxim MAX3191x industrial serializer, a very interesting piece of professional I/O hardware. - Uniphier GPIO driver. This is the GPIO block from the recent Socionext (ex Fujitsu and Panasonic) platform. - Tegra 186 driver. This is based on the new banked GPIO infrastructure. Other improvements: - Some documentation improvements. - Wakeup support for the DesignWare DWAPB GPIO controller. - Reset line support on the DesignWare DWAPB GPIO controller. - Several non-critical bug fixes and improvements for the Broadcom BRCMSTB driver. - Misc non-critical bug fixes like exotic errorpaths, removal of dead code etc. - Explicit comments on fall-through switch() statements" * tag 'gpio-v4.15-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (65 commits) gpio: tegra186: Remove tegra186_gpio_lock_class gpio: rcar: Add r8a77995 (R-Car D3) support pinctrl: bcm2835: Fix some merge fallout gpio: Fix undefined lock_dep_class gpio: Automatically add lockdep keys gpio: Introduce struct gpio_irq_chip.first gpio: Disambiguate struct gpio_irq_chip.nested gpio: Add Tegra186 support gpio: Export gpiochip_irq_{map,unmap}() gpio: Implement tighter IRQ chip integration gpio: Move lock_key into struct gpio_irq_chip gpio: Move irq_valid_mask into struct gpio_irq_chip gpio: Move irq_nested into struct gpio_irq_chip gpio: Move irq_chained_parent to struct gpio_irq_chip gpio: Move irq_default_type to struct gpio_irq_chip gpio: Move irq_handler to struct gpio_irq_chip gpio: Move irqdomain into struct gpio_irq_chip gpio: Move irqchip into struct gpio_irq_chip gpio: Introduce struct gpio_irq_chip pinctrl: armada-37xx: remove unused variable ... |
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README |
This directory attempts to document the ABI between the Linux kernel and userspace, and the relative stability of these interfaces. Due to the everchanging nature of Linux, and the differing maturity levels, these interfaces should be used by userspace programs in different ways. We have four different levels of ABI stability, as shown by the four different subdirectories in this location. Interfaces may change levels of stability according to the rules described below. The different levels of stability are: stable/ This directory documents the interfaces that the developer has defined to be stable. Userspace programs are free to use these interfaces with no restrictions, and backward compatibility for them will be guaranteed for at least 2 years. Most interfaces (like syscalls) are expected to never change and always be available. testing/ This directory documents interfaces that are felt to be stable, as the main development of this interface has been completed. The interface can be changed to add new features, but the current interface will not break by doing this, unless grave errors or security problems are found in them. Userspace programs can start to rely on these interfaces, but they must be aware of changes that can occur before these interfaces move to be marked stable. Programs that use these interfaces are strongly encouraged to add their name to the description of these interfaces, so that the kernel developers can easily notify them if any changes occur (see the description of the layout of the files below for details on how to do this.) obsolete/ This directory documents interfaces that are still remaining in the kernel, but are marked to be removed at some later point in time. The description of the interface will document the reason why it is obsolete and when it can be expected to be removed. removed/ This directory contains a list of the old interfaces that have been removed from the kernel. Every file in these directories will contain the following information: What: Short description of the interface Date: Date created KernelVersion: Kernel version this feature first showed up in. Contact: Primary contact for this interface (may be a mailing list) Description: Long description of the interface and how to use it. Users: All users of this interface who wish to be notified when it changes. This is very important for interfaces in the "testing" stage, so that kernel developers can work with userspace developers to ensure that things do not break in ways that are unacceptable. It is also important to get feedback for these interfaces to make sure they are working in a proper way and do not need to be changed further. How things move between levels: Interfaces in stable may move to obsolete, as long as the proper notification is given. Interfaces may be removed from obsolete and the kernel as long as the documented amount of time has gone by. Interfaces in the testing state can move to the stable state when the developers feel they are finished. They cannot be removed from the kernel tree without going through the obsolete state first. It's up to the developer to place their interfaces in the category they wish for it to start out in. Notable bits of non-ABI, which should not under any circumstances be considered stable: - Kconfig. Userspace should not rely on the presence or absence of any particular Kconfig symbol, in /proc/config.gz, in the copy of .config commonly installed to /boot, or in any invocation of the kernel build process. - Kernel-internal symbols. Do not rely on the presence, absence, location, or type of any kernel symbol, either in System.map files or the kernel binary itself. See Documentation/process/stable-api-nonsense.rst.