1 2GPIO configuration. 3=================== 4 51. Properties for GPIO Controllers 6 71.1 #gpio-cells 8 9Property: #gpio-cells 10 11Value type: <u32> 12 13Description: The #gpio-cells property defines the number of cells required 14 to encode a gpio specifier. 15 16 171.2 gpio-controller 18 19Property: gpio-controller 20 21Value type: <empty> 22 23Description: The presence of a gpio-controller property defines a node as a 24 GPIO controller node. 25 26 271.3 pin-count 28 29Property: pin-count 30 31Value type: <u32> 32 33Description: The pin-count property defines the number of GPIO pins. 34 35 361.4 Example 37 38 GPIO: gpio@10100 { 39 #gpio-cells = <3>; 40 compatible = "mrvl,gpio"; 41 reg = <0x10100 0x20>; 42 gpio-controller; 43 interrupts = <6 7 8 9>; 44 interrupt-parent = <&PIC>; 45 pin-count = <50> 46 }; 47 482. Properties for GPIO consumer nodes. 49 502.1 gpios 51 52Property: gpios 53 54Value type: <prop-encoded-array> encoded as arbitrary number of GPIO 55 specifiers. 56 57Description: The gpios property of a device node defines the GPIO or GPIOs 58 that are used by the device. The value of the gpios property 59 consists of an arbitrary number of GPIO specifiers. 60 61 The first cell of the GPIO specifier is phandle of the node's 62 parent GPIO controller and remaining cells are defined by the 63 binding describing the GPIO parent, typically include 64 information like pin number, direction and various flags. 65 66Example: 67 gpios = <&GPIO 0 1 /* GPIO[0]: FLAGS */ 68 &GPIO 1 2>; /* GPIO[1]: FLAGS */ 69 70 713. GPIO controller specifier 72 73 <phandle pin dir flags> 74 75 76pin: 0-MAX GPIO pin number. 77 78flags: 79 Available flags are listed in sys/conf.h. Following combination 80 can be supported by the controller. For details please refer 81 to controller's GPIO reference manual. 82 83 GPIO_PIN_INPUT 0x0001 Input direction 84 GPIO_PIN_OUTPUT 0x0002 Output direction 85 GPIO_PIN_OPENDRAIN 0x0004 Open-drain output 86 GPIO_PIN_OPENSOURCE 0x0008 Open-source output 87 GPIO_PIN_PUSHPULL 0x0010 Push-pull output 88 GPIO_PIN_TRISTATE 0x0020 Output disabled 89 GPIO_PIN_PULLUP 0x0040 Internal pull-up enabled 90 GPIO_PIN_PULLDOWN 0x0080 Internal pull-down enabled 91 GPIO_PIN_INVIN 0x0100 Invert input 92 GPIO_PIN_INVOUT 0x0200 Invert output 93 GPIO_PIN_PULSATE 0x0400 Pulsate in hardware 94 GPIO_PIN_IRQ_POL_EDG 0x0800 IRQ active single edge 95 GPIO_PIN_IRQ_POL_DBL 0x1000 IRQ active double edge 96 GPIO_PIN_IRQ_POL_LVL 0x2000 IRQ active level 97 GPIO_PIN_IRQ_DEBOUNCE 0x4000 Debounce on IRQ pin 98 99Example: 100 gpios = <&GPIO 0 0x00000001 /* GPIO[0]: IN */ 101 &GPIO 1 0x00000002 /* GPIO[1]: OUT */ 102 &GPIO 2 0x00000801 /* GPIO[2]: IN, IRQ (edge) */ 103 &GPIO 3 0x00004001 /* GPIO[3]: IN, IRQ (level) */ 104 ... 105 &GPIO 10 0x00000401>; /* GPIO[10]: OUT, blink */ 106