Simon Arlott | e1b2dc7 | 2012-09-27 22:10:11 -0600 | [diff] [blame] | 1 | Broadcom BCM2835 GPIO (and pinmux) controller |
| 2 | |
| 3 | The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt |
| 4 | controller, and pinmux/control device. |
| 5 | |
| 6 | Required properties: |
| 7 | - compatible: "brcm,bcm2835-gpio" |
Masanari Iida | 372c1d6 | 2013-04-10 22:33:46 +0900 | [diff] [blame] | 8 | - reg: Should contain the physical address of the GPIO module's registers. |
Simon Arlott | e1b2dc7 | 2012-09-27 22:10:11 -0600 | [diff] [blame] | 9 | - gpio-controller: Marks the device node as a GPIO controller. |
| 10 | - #gpio-cells : Should be two. The first cell is the pin number and the |
| 11 | second cell is used to specify optional parameters: |
| 12 | - bit 0 specifies polarity (0 for normal, 1 for inverted) |
| 13 | - interrupts : The interrupt outputs from the controller. One interrupt per |
| 14 | individual bank followed by the "all banks" interrupt. |
| 15 | - interrupt-controller: Marks the device node as an interrupt controller. |
| 16 | - #interrupt-cells : Should be 2. |
| 17 | The first cell is the GPIO number. |
| 18 | The second cell is used to specify flags: |
| 19 | bits[3:0] trigger type and level flags: |
| 20 | 1 = low-to-high edge triggered. |
| 21 | 2 = high-to-low edge triggered. |
| 22 | 4 = active high level-sensitive. |
| 23 | 8 = active low level-sensitive. |
| 24 | Valid combinations are 1, 2, 3, 4, 8. |
| 25 | |
| 26 | Please refer to ../gpio/gpio.txt for a general description of GPIO bindings. |
| 27 | |
| 28 | Please refer to pinctrl-bindings.txt in this directory for details of the |
| 29 | common pinctrl bindings used by client devices, including the meaning of the |
| 30 | phrase "pin configuration node". |
| 31 | |
| 32 | Each pin configuration node lists the pin(s) to which it applies, and one or |
| 33 | more of the mux function to select on those pin(s), and pull-up/down |
| 34 | configuration. Each subnode only affects those parameters that are explicitly |
| 35 | listed. In other words, a subnode that lists only a mux function implies no |
| 36 | information about any pull configuration. Similarly, a subnode that lists only |
| 37 | a pul parameter implies no information about the mux function. |
| 38 | |
| 39 | Required subnode-properties: |
| 40 | - brcm,pins: An array of cells. Each cell contains the ID of a pin. Valid IDs |
| 41 | are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53. |
| 42 | |
| 43 | Optional subnode-properties: |
| 44 | - brcm,function: Integer, containing the function to mux to the pin(s): |
| 45 | 0: GPIO in |
| 46 | 1: GPIO out |
| 47 | 2: alt5 |
| 48 | 3: alt4 |
| 49 | 4: alt0 |
| 50 | 5: alt1 |
| 51 | 6: alt2 |
| 52 | 7: alt3 |
| 53 | - brcm,pull: Integer, representing the pull-down/up to apply to the pin(s): |
| 54 | 0: none |
| 55 | 1: down |
| 56 | 2: up |
| 57 | |
| 58 | Each of brcm,function and brcm,pull may contain either a single value which |
| 59 | will be applied to all pins in brcm,pins, or 1 value for each entry in |
| 60 | brcm,pins. |
| 61 | |
| 62 | Example: |
| 63 | |
| 64 | gpio: gpio { |
| 65 | compatible = "brcm,bcm2835-gpio"; |
| 66 | reg = <0x2200000 0xb4>; |
| 67 | interrupts = <2 17>, <2 19>, <2 18>, <2 20>; |
| 68 | |
| 69 | gpio-controller; |
| 70 | #gpio-cells = <2>; |
| 71 | |
| 72 | interrupt-controller; |
| 73 | #interrupt-cells = <2>; |
| 74 | }; |