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6aa2f9441f
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
...
Broadcom introduced new bus as replacement for older SSB. It is based on AMBA, however from programming point of view there is nothing AMBA specific we use. Standard AMBA drivers are platform specific, have hardcoded addresses and use AMBA standard fields like CID and PID. In case of Broadcom's cards every device consists of: 1) Broadcom specific AMBA device. It is put on AMBA bus, but can not be treated as standard AMBA device. Reading it's CID or PID can cause machine lockup. 2) AMBA standard devices called ports or wrappers. They have CIDs (AMBA_CID) and PIDs (0x103BB369), but we do not use that info for anything. One of that devices is used for managing Broadcom specific core. Addresses of AMBA devices are not hardcoded in driver and have to be read from EPROM. In this situation we decided to introduce separated bus. It can contain up to 16 devices identified by Broadcom specific fields: manufacturer, id, revision and class.