ambiq,gpio
Vendor: Ambiq Micro, Inc.
Description
Ambiq GPIO provides the GPIO pin mapping for GPIO child nodes.
The Ambiq Apollo4x soc designs a single GPIO port with 128 pins.
It uses 128 continuous 32-bit registers to configure the GPIO pins.
This binding provides a pin mapping to solve the limitation of the maximum
32 pins handling in GPIO driver API.
The Ambiq Apollo4x soc should define one "ambiq,gpio" parent node in soc
devicetree and some child nodes which are compatible with "ambiq,gpio-bank"
under this parent node.
Here is an example of how a "ambiq,gpio" node can be used with the combined
gpio child nodes:
gpio: gpio@40010000 {
compatible = "ambiq,gpio";
gpio-map-mask = <0xffffffe0 0xffffffc0>;
gpio-map-pass-thru = <0x1f 0x3f>;
gpio-map = <
0x00 0x0 &gpio0_31 0x0 0x0
0x20 0x0 &gpio32_63 0x0 0x0
0x40 0x0 &gpio64_95 0x0 0x0
0x60 0x0 &gpio96_127 0x0 0x0
>;
reg = <0x40010000>;
#gpio-cells = <2>;
#address-cells = <1>;
#size-cells = <0>;
ranges;
gpio0_31: gpio0_31@0 {
compatible = "ambiq,gpio-bank";
gpio-controller;
#gpio-cells = <2>;
reg = <0>;
interrupts = <56 0>;
status = "disabled";
};
gpio32_63: gpio32_63@80 {
compatible = "ambiq,gpio-bank";
gpio-controller;
#gpio-cells = <2>;
reg = <0x80>;
interrupts = <57 0>;
status = "disabled";
};
gpio64_95: gpio64_95@100 {
compatible = "ambiq,gpio-bank";
gpio-controller;
#gpio-cells = <2>;
reg = <0x100>;
interrupts = <58 0>;
status = "disabled";
};
gpio96_127: gpio96_127@180 {
compatible = "ambiq,gpio-bank";
gpio-controller;
#gpio-cells = <2>;
reg = <0x180>;
interrupts = <59 0>;
status = "disabled";
};
};
In the above example, the gpio@40010000 is a "ambiq,gpio" parent node which
provides the base register address 0x40010000. It has four "ambiq,gpio-bank"
child nodes. Each of them covers 32 pins (the default value of "ngpios"
property is 32). The "reg" property of child nodes defines the register
address offset. The register address of pin described in gpio-cells can be
obtained by: base address + child address offset + (pin << 2). For example:
the address of pin 20 of gpio32_63@80 node is (0x40010000 + 0x80 + (20 << 2))
= 0x400100D0 and the real GPIO pin number of this pin in soc is (20 + 32)
= 52.
Properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
|
|
This property is required. |
|
|
|
|
|
|
|
|
Number of items to expect in a GPIO specifier
This property is required. |
Deprecated properties not inherited from the base binding file.
(None)
Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “ambiq,gpio” compatible.
Name |
Type |
Details |
|---|---|---|
|
|
indicates the operational status of a device
Legal values: See Important properties for more information. |
|
|
compatible strings
This property is required. See Important properties for more information. |
|
|
register space
See Important properties for more information. |
|
|
name of each register space
|
|
|
interrupts for device
See Important properties for more information. |
|
|
extended interrupt specifier for device
|
|
|
name of each interrupt
|
|
|
phandle to interrupt controller node
|
|
|
Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
|
|
Clock gate information
|
|
|
name of each clock
|
|
|
number of address cells in reg property
|
|
|
number of size cells in reg property
|
|
|
DMA channels specifiers
|
|
|
Provided names of DMA channel specifiers
|
|
|
IO channels specifiers
|
|
|
Provided names of IO channel specifiers
|
|
|
mailbox / IPM channels specifiers
|
|
|
Provided names of mailbox / IPM channel specifiers
|
|
|
Power domain specifiers
|
|
|
Provided names of power domain specifiers
|
|
|
Number of cells in power-domains property
|
|
|
Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
|
|
|
Property to identify that a device can be used as wake up source.
When this property is provided a specific flag is set into the
device that tells the system that the device is capable of
wake up the system.
Wake up capable devices are disabled (interruptions will not wake up
the system) by default but they can be enabled at runtime if necessary.
|
|
|
Automatically configure the device for runtime power management after the
init function runs.
|
|
|
List of power states that will disable this device power.
|