mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
e61941d1e9
Added generic pin configuration and multiplexing support, and should be preferred than brcm legacy one. Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Eric Anholt <eric@anholt.net> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
93 lines
3.0 KiB
Plaintext
93 lines
3.0 KiB
Plaintext
Broadcom BCM2835 GPIO (and pinmux) controller
|
|
|
|
The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt
|
|
controller, and pinmux/control device.
|
|
|
|
Required properties:
|
|
- compatible: "brcm,bcm2835-gpio"
|
|
- reg: Should contain the physical address of the GPIO module's registers.
|
|
- gpio-controller: Marks the device node as a GPIO controller.
|
|
- #gpio-cells : Should be two. The first cell is the pin number and the
|
|
second cell is used to specify optional parameters:
|
|
- bit 0 specifies polarity (0 for normal, 1 for inverted)
|
|
- interrupts : The interrupt outputs from the controller. One interrupt per
|
|
individual bank followed by the "all banks" interrupt.
|
|
- interrupt-controller: Marks the device node as an interrupt controller.
|
|
- #interrupt-cells : Should be 2.
|
|
The first cell is the GPIO number.
|
|
The second cell is used to specify flags:
|
|
bits[3:0] trigger type and level flags:
|
|
1 = low-to-high edge triggered.
|
|
2 = high-to-low edge triggered.
|
|
4 = active high level-sensitive.
|
|
8 = active low level-sensitive.
|
|
Valid combinations are 1, 2, 3, 4, 8.
|
|
|
|
Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
|
|
|
|
Please refer to pinctrl-bindings.txt in this directory for details of the
|
|
common pinctrl bindings used by client devices, including the meaning of the
|
|
phrase "pin configuration node".
|
|
|
|
Each pin configuration node lists the pin(s) to which it applies, and one or
|
|
more of the mux function to select on those pin(s), and pull-up/down
|
|
configuration. Each subnode only affects those parameters that are explicitly
|
|
listed. In other words, a subnode that lists only a mux function implies no
|
|
information about any pull configuration. Similarly, a subnode that lists only
|
|
a pul parameter implies no information about the mux function.
|
|
|
|
The BCM2835 pin configuration and multiplexing supports the generic bindings.
|
|
For details on each properties, you can refer to ./pinctrl-bindings.txt.
|
|
|
|
Required sub-node properties:
|
|
- pins
|
|
- function
|
|
|
|
Optional sub-node properties:
|
|
- bias-disable
|
|
- bias-pull-up
|
|
- bias-pull-down
|
|
- output-high
|
|
- output-low
|
|
|
|
Legacy pin configuration and multiplexing binding:
|
|
*** (Its use is deprecated, use generic multiplexing and configuration
|
|
bindings instead)
|
|
|
|
Required subnode-properties:
|
|
- brcm,pins: An array of cells. Each cell contains the ID of a pin. Valid IDs
|
|
are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53.
|
|
|
|
Optional subnode-properties:
|
|
- brcm,function: Integer, containing the function to mux to the pin(s):
|
|
0: GPIO in
|
|
1: GPIO out
|
|
2: alt5
|
|
3: alt4
|
|
4: alt0
|
|
5: alt1
|
|
6: alt2
|
|
7: alt3
|
|
- brcm,pull: Integer, representing the pull-down/up to apply to the pin(s):
|
|
0: none
|
|
1: down
|
|
2: up
|
|
|
|
Each of brcm,function and brcm,pull may contain either a single value which
|
|
will be applied to all pins in brcm,pins, or 1 value for each entry in
|
|
brcm,pins.
|
|
|
|
Example:
|
|
|
|
gpio: gpio {
|
|
compatible = "brcm,bcm2835-gpio";
|
|
reg = <0x2200000 0xb4>;
|
|
interrupts = <2 17>, <2 19>, <2 18>, <2 20>;
|
|
|
|
gpio-controller;
|
|
#gpio-cells = <2>;
|
|
|
|
interrupt-controller;
|
|
#interrupt-cells = <2>;
|
|
};
|