Lines Matching refs:GPIO

1 This is a place for planning the ongoing long-term work in the GPIO
5 GPIO descriptors
7 Starting with commit 79a9becda894 the GPIO subsystem embarked on a journey
8 to move away from the global GPIO numberspace and toward a descriptor-based
9 approach. This means that GPIO consumers, drivers and machine descriptions
10 ideally have no use or idea of the global GPIO numberspace that has/was
11 used in the inception of the GPIO subsystem.
16 The underlying motivation for this is that the GPIO numberspace has become
23 Linux GPIO number as those descriptions are external to the Linux kernel
24 and treat GPIO lines as abstract entities.
26 The runtime-assigned GPIO numberspace (what you get if you assign the GPIO
29 ordering of independent GPIO chips essentially unpredictable, as their base
32 The best way to get out of the problem is to make the global GPIO numbers
33 unimportant by simply not using them. GPIO descriptors deal with this.
37 - Convert all GPIO device drivers to only #include <linux/gpio/driver.h>
44   implicitly does not use global GPIO numbers.
55 driver infrastructure for doing simpler MMIO GPIO devices and there was
63   GPIO for all current users (see below). Delete struct of_mm_gpio_chip,
69   GPIO lines from the device tree. This can be tricky and often ivolves
72 - Pull semantics for legacy device tree (OF) GPIO lookups into
86 This legacy header is a one stop shop for anything GPIO is closely tied
87 to the global GPIO numberspace. The endgame of the above refactorings will
95 Collect GPIO drivers from arch/* and other places that should be placed
99 In some cases it makes sense to create a GPIO chip from the local driver
107 Generic MMIO GPIO
109 The GPIO drivers can utilize the generic MMIO helper library in many
116   dry-code conversions to MMIO GPIO for maintainers to test
118 - Expand the MMIO GPIO or write a new library for regmap-based I/O
119   helpers for GPIO drivers on regmap that simply use offsets
120   0..n in some register to drive GPIO lines
122 - Expand the MMIO GPIO or write a new library for port-mapped I/O
130 try to cover any generic kind of irqchip cascaded from a GPIO.
138 There are already ways to use pin control as back-end for GPIO and
141 use of the global GPIO numbers. Once the above is complete, it may
143 multiplexing, pin configuration, GPIO, etc selectable options in one
144 and the same pin control and GPIO subsystem.
156 as it relies on the global GPIO numberspace that assume a strict
157 order of global GPIO numbers that do not change between boots
162 GPIO lines that can do everything that sysfs can do today: one