| 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 registes. |
| - 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. |
| |
| 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>; |
| }; |