diff options
Diffstat (limited to 'Documentation/devicetree/bindings')
| -rw-r--r-- | Documentation/devicetree/bindings/pinctrl/samsung-pinctrl.txt | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pinctrl/samsung-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/samsung-pinctrl.txt new file mode 100644 index 00000000000..03dee50532f --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/samsung-pinctrl.txt @@ -0,0 +1,196 @@ +Samsung GPIO and Pin Mux/Config controller + +Samsung's ARM based SoC's integrates a GPIO and Pin mux/config hardware +controller. It controls the input/output settings on the available pads/pins +and also provides ability to multiplex and configure the output of various +on-chip controllers onto these pads. + +Required Properties: +- compatible: should be one of the following. + - "samsung,pinctrl-exynos4210": for Exynos4210 compatible pin-controller. + - "samsung,pinctrl-exynos5250": for Exynos5250 compatible pin-controller. + +- reg: Base address of the pin controller hardware module and length of + the address space it occupies. + +- interrupts: interrupt specifier for the controller. The format and value of + the interrupt specifier depends on the interrupt parent for the controller. + +- Pin mux/config groups as child nodes: The pin mux (selecting pin function + mode) and pin config (pull up/down, driver strength) settings are represented + as child nodes of the pin-controller node. There should be atleast one + child node and there is no limit on the count of these child nodes. + + The child node should contain a list of pin(s) on which a particular pin + function selection or pin configuration (or both) have to applied. This + list of pins is specified using the property name "samsung,pins". There + should be atleast one pin specfied for this property and there is no upper + limit on the count of pins that can be specified. The pins are specified + using pin names which are derived from the hardware manual of the SoC. As + an example, the pins in GPA0 bank of the pin controller can be represented + as "gpa0-0", "gpa0-1", "gpa0-2" and so on. The names should be in lower case. + The format of the pin names should be (as per the hardware manual) + "[pin bank name]-[pin number within the bank]". + + The pin function selection that should be applied on the pins listed in the + child node is specified using the "samsung,pin-function" property. The value + of this property that should be applied to each of the pins listed in the + "samsung,pins" property should be picked from the hardware manual of the SoC + for the specified pin group. This property is optional in the child node if + no specific function selection is desired for the pins listed in the child + node. The value of this property is used as-is to program the pin-controller + function selector register of the pin-bank. + + The child node can also optionally specify one or more of the pin + configuration that should be applied on all the pins listed in the + "samsung,pins" property of the child node. The following pin configuration + properties are supported. + + - samsung,pin-pud: Pull up/down configuration. + - samsung,pin-drv: Drive strength configuration. + - samsung,pin-pud-pdn: Pull up/down configuration in power down mode. + - samsung,pin-drv-pdn: Drive strength configuration in power down mode. + + The values specified by these config properties should be derived from the + hardware manual and these values are programmed as-is into the pin + pull up/down and driver strength register of the pin-controller. + + Note: A child should include atleast a pin function selection property or + pin configuration property (one or more) or both. + + The client nodes that require a particular pin function selection and/or + pin configuration should use the bindings listed in the "pinctrl-bindings.txt" + file. + +External GPIO and Wakeup Interrupts: + +The controller supports two types of external interrupts over gpio. The first +is the external gpio interrupt and second is the external wakeup interrupts. +The difference between the two is that the external wakeup interrupts can be +used as system wakeup events. + +A. External GPIO Interrupts: For supporting external gpio interrupts, the + following properties should be specified in the pin-controller device node. + +- interrupt-controller: identifies the controller node as interrupt-parent. +- #interrupt-cells: the value of this property should be 2. + - First Cell: represents the external gpio interrupt number local to the + external gpio interrupt space of the controller. + - Second Cell: flags to identify the type of the interrupt + - 1 = rising edge triggered + - 2 = falling edge triggered + - 3 = rising and falling edge triggered + - 4 = high level triggered + - 8 = low level triggered + +B. External Wakeup Interrupts: For supporting external wakeup interrupts, a + child node representing the external wakeup interrupt controller should be + included in the pin-controller device node. This child node should include + the following properties. + + - compatible: identifies the type of the external wakeup interrupt controller + The possible values are: + - samsung,exynos4210-wakeup-eint: represents wakeup interrupt controller + found on Samsung Exynos4210 SoC. + - interrupt-parent: phandle of the interrupt parent to which the external + wakeup interrupts are forwarded to. + - interrupt-controller: identifies the node as interrupt-parent. + - #interrupt-cells: the value of this property should be 2 + - First Cell: represents the external wakeup interrupt number local to + the external wakeup interrupt space of the controller. + - Second Cell: flags to identify the type of the interrupt + - 1 = rising edge triggered + - 2 = falling edge triggered + - 3 = rising and falling edge triggered + - 4 = high level triggered + - 8 = low level triggered + +Aliases: + +All the pin controller nodes should be represented in the aliases node using +the following format 'pinctrl{n}' where n is a unique number for the alias. + +Example 1: A pin-controller node with pin groups. + + pinctrl_0: pinctrl@11400000 { + compatible = "samsung,pinctrl-exynos4210"; + reg = <0x11400000 0x1000>; + interrupts = <0 47 0>; + + uart0_data: uart0-data { + samsung,pins = "gpa0-0", "gpa0-1"; + samsung,pin-function = <2>; + samsung,pin-pud = <0>; + samsung,pin-drv = <0>; + }; + + uart0_fctl: uart0-fctl { + samsung,pins = "gpa0-2", "gpa0-3"; + samsung,pin-function = <2>; + samsung,pin-pud = <0>; + samsung,pin-drv = <0>; + }; + + uart1_data: uart1-data { + samsung,pins = "gpa0-4", "gpa0-5"; + samsung,pin-function = <2>; + samsung,pin-pud = <0>; + samsung,pin-drv = <0>; + }; + + uart1_fctl: uart1-fctl { + samsung,pins = "gpa0-6", "gpa0-7"; + samsung,pin-function = <2>; + samsung,pin-pud = <0>; + samsung,pin-drv = <0>; + }; + + i2c2_bus: i2c2-bus { + samsung,pins = "gpa0-6", "gpa0-7"; + samsung,pin-function = <3>; + samsung,pin-pud = <3>; + samsung,pin-drv = <0>; + }; + }; + +Example 2: A pin-controller node with external wakeup interrupt controller node. + + pinctrl_1: pinctrl@11000000 { + compatible = "samsung,pinctrl-exynos4210"; + reg = <0x11000000 0x1000>; + interrupts = <0 46 0>; + interrupt-controller; + #interrupt-cells = <2>; + + wakup_eint: wakeup-interrupt-controller { + compatible = "samsung,exynos4210-wakeup-eint"; + interrupt-parent = <&gic>; + interrupt-controller; + #interrupt-cells = <2>; + interrupts = <0 16 0>, <0 17 0>, <0 18 0>, <0 19 0>, + <0 20 0>, <0 21 0>, <0 22 0>, <0 23 0>, + <0 24 0>, <0 25 0>, <0 26 0>, <0 27 0>, + <0 28 0>, <0 29 0>, <0 30 0>, <0 31 0>, + <0 32 0>; + }; + }; + +Example 3: A uart client node that supports 'default' and 'flow-control' states. + + uart@13800000 { + compatible = "samsung,exynos4210-uart"; + reg = <0x13800000 0x100>; + interrupts = <0 52 0>; + pinctrl-names = "default", "flow-control; + pinctrl-0 = <&uart0_data>; + pinctrl-1 = <&uart0_data &uart0_fctl>; + }; + +Example 4: Set up the default pin state for uart controller. + + static int s3c24xx_serial_probe(struct platform_device *pdev) { + struct pinctrl *pinctrl; + ... + ... + pinctrl = devm_pinctrl_get_select_default(&pdev->dev); + } |