342 lines
12 KiB
Plaintext
342 lines
12 KiB
Plaintext
|
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,s3c2412-pinctrl": for S3C2412-compatible pin-controller,
|
||
|
|
- "samsung,s3c2416-pinctrl": for S3C2416-compatible pin-controller,
|
||
|
|
- "samsung,s3c2440-pinctrl": for S3C2440-compatible pin-controller,
|
||
|
|
- "samsung,s3c2450-pinctrl": for S3C2450-compatible pin-controller,
|
||
|
|
- "samsung,s3c64xx-pinctrl": for S3C64xx-compatible pin-controller,
|
||
|
|
- "samsung,s5pv210-pinctrl": for S5PV210-compatible pin-controller,
|
||
|
|
- "samsung,exynos4210-pinctrl": for Exynos4210 compatible pin-controller.
|
||
|
|
- "samsung,exynos4x12-pinctrl": for Exynos4x12 compatible pin-controller.
|
||
|
|
- "samsung,exynos5250-pinctrl": for Exynos5250 compatible pin-controller.
|
||
|
|
- "samsung,exynos5260-pinctrl": for Exynos5260 compatible pin-controller.
|
||
|
|
- "samsung,exynos5420-pinctrl": for Exynos5420 compatible pin-controller.
|
||
|
|
|
||
|
|
- reg: Base address of the pin controller hardware module and length of
|
||
|
|
the address space it occupies.
|
||
|
|
|
||
|
|
- Pin banks as child nodes: Pin banks of the controller are represented by child
|
||
|
|
nodes of the controller node. Bank name is taken from name of the node. Each
|
||
|
|
bank node must contain following properties:
|
||
|
|
|
||
|
|
- gpio-controller: identifies the node as a gpio controller and pin bank.
|
||
|
|
- #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO
|
||
|
|
binding is used, the amount of cells must be specified as 2. See the below
|
||
|
|
mentioned gpio binding representation for description of particular cells.
|
||
|
|
|
||
|
|
Eg: <&gpx2 6 0>
|
||
|
|
<[phandle of the gpio controller node]
|
||
|
|
[pin number within the gpio controller]
|
||
|
|
[flags]>
|
||
|
|
|
||
|
|
Values for gpio specifier:
|
||
|
|
- Pin number: is a value between 0 to 7.
|
||
|
|
- Flags: 0 - Active High
|
||
|
|
1 - Active Low
|
||
|
|
|
||
|
|
- 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. It is
|
||
|
|
also possible for a child node to consist of several further child nodes
|
||
|
|
to allow grouping multiple pinctrl groups into one. The format of second
|
||
|
|
level child nodes is exactly the same as for first level ones and is
|
||
|
|
described below.
|
||
|
|
|
||
|
|
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-val: Initial value of pin output buffer.
|
||
|
|
- 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-parent: phandle of the interrupt parent to which the external
|
||
|
|
GPIO interrupts are forwarded to.
|
||
|
|
- interrupts: interrupt specifier for the controller. The format and value of
|
||
|
|
the interrupt specifier depends on the interrupt parent for the controller.
|
||
|
|
|
||
|
|
In addition, following properties must be present in node of every bank
|
||
|
|
of pins supporting GPIO interrupts:
|
||
|
|
|
||
|
|
- 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,s3c2410-wakeup-eint: represents wakeup interrupt controller
|
||
|
|
found on Samsung S3C24xx SoCs except S3C2412 and S3C2413,
|
||
|
|
- samsung,s3c2412-wakeup-eint: represents wakeup interrupt controller
|
||
|
|
found on Samsung S3C2412 and S3C2413 SoCs,
|
||
|
|
- samsung,s3c64xx-wakeup-eint: represents wakeup interrupt controller
|
||
|
|
found on Samsung S3C64xx SoCs,
|
||
|
|
- samsung,exynos4210-wakeup-eint: represents wakeup interrupt controller
|
||
|
|
found on Samsung Exynos4210 and S5PC110/S5PV210 SoCs.
|
||
|
|
- interrupt-parent: phandle of the interrupt parent to which the external
|
||
|
|
wakeup interrupts are forwarded to.
|
||
|
|
- interrupts: interrupt used by multiplexed wakeup interrupts.
|
||
|
|
|
||
|
|
In addition, following properties must be present in node of every bank
|
||
|
|
of pins supporting wake-up interrupts:
|
||
|
|
|
||
|
|
- 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
|
||
|
|
|
||
|
|
Node of every bank of pins supporting direct wake-up interrupts (without
|
||
|
|
multiplexing) must contain following properties:
|
||
|
|
|
||
|
|
- interrupt-parent: phandle of the interrupt parent to which the external
|
||
|
|
wakeup interrupts are forwarded to.
|
||
|
|
- interrupts: interrupts of the interrupt parent which are used for external
|
||
|
|
wakeup interrupts from pins of the bank, must contain interrupts for all
|
||
|
|
pins of the bank.
|
||
|
|
|
||
|
|
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: A pin-controller node with pin banks:
|
||
|
|
|
||
|
|
pinctrl_0: pinctrl@11400000 {
|
||
|
|
compatible = "samsung,exynos4210-pinctrl";
|
||
|
|
reg = <0x11400000 0x1000>;
|
||
|
|
interrupts = <0 47 0>;
|
||
|
|
|
||
|
|
/* ... */
|
||
|
|
|
||
|
|
/* Pin bank without external interrupts */
|
||
|
|
gpy0: gpy0 {
|
||
|
|
gpio-controller;
|
||
|
|
#gpio-cells = <2>;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* ... */
|
||
|
|
|
||
|
|
/* Pin bank with external GPIO or muxed wake-up interrupts */
|
||
|
|
gpj0: gpj0 {
|
||
|
|
gpio-controller;
|
||
|
|
#gpio-cells = <2>;
|
||
|
|
|
||
|
|
interrupt-controller;
|
||
|
|
#interrupt-cells = <2>;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* ... */
|
||
|
|
|
||
|
|
/* Pin bank with external direct wake-up interrupts */
|
||
|
|
gpx0: gpx0 {
|
||
|
|
gpio-controller;
|
||
|
|
#gpio-cells = <2>;
|
||
|
|
|
||
|
|
interrupt-controller;
|
||
|
|
interrupt-parent = <&gic>;
|
||
|
|
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>;
|
||
|
|
#interrupt-cells = <2>;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* ... */
|
||
|
|
};
|
||
|
|
|
||
|
|
Example 1: A pin-controller node with pin groups.
|
||
|
|
|
||
|
|
pinctrl_0: pinctrl@11400000 {
|
||
|
|
compatible = "samsung,exynos4210-pinctrl";
|
||
|
|
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>;
|
||
|
|
};
|
||
|
|
|
||
|
|
sd4_bus8: sd4-bus-width8 {
|
||
|
|
part-1 {
|
||
|
|
samsung,pins = "gpk0-3", "gpk0-4",
|
||
|
|
"gpk0-5", "gpk0-6";
|
||
|
|
samsung,pin-function = <3>;
|
||
|
|
samsung,pin-pud = <3>;
|
||
|
|
samsung,pin-drv = <3>;
|
||
|
|
};
|
||
|
|
part-2 {
|
||
|
|
samsung,pins = "gpk1-3", "gpk1-4",
|
||
|
|
"gpk1-5", "gpk1-6";
|
||
|
|
samsung,pin-function = <4>;
|
||
|
|
samsung,pin-pud = <4>;
|
||
|
|
samsung,pin-drv = <3>;
|
||
|
|
};
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
Example 2: A pin-controller node with external wakeup interrupt controller node.
|
||
|
|
|
||
|
|
pinctrl_1: pinctrl@11000000 {
|
||
|
|
compatible = "samsung,exynos4210-pinctrl";
|
||
|
|
reg = <0x11000000 0x1000>;
|
||
|
|
interrupts = <0 46 0>
|
||
|
|
|
||
|
|
/* ... */
|
||
|
|
|
||
|
|
wakeup-interrupt-controller {
|
||
|
|
compatible = "samsung,exynos4210-wakeup-eint";
|
||
|
|
interrupt-parent = <&gic>;
|
||
|
|
interrupts = <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);
|
||
|
|
}
|
||
|
|
|
||
|
|
Example 5: A display port client node that supports 'default' pinctrl state
|
||
|
|
and gpio binding.
|
||
|
|
|
||
|
|
display-port-controller {
|
||
|
|
/* ... */
|
||
|
|
|
||
|
|
samsung,hpd-gpio = <&gpx2 6 0>;
|
||
|
|
pinctrl-names = "default";
|
||
|
|
pinctrl-0 = <&dp_hpd>;
|
||
|
|
};
|
||
|
|
|
||
|
|
Example 6: Request the gpio for display port controller
|
||
|
|
|
||
|
|
static int exynos_dp_probe(struct platform_device *pdev)
|
||
|
|
{
|
||
|
|
int hpd_gpio, ret;
|
||
|
|
struct device *dev = &pdev->dev;
|
||
|
|
struct device_node *dp_node = dev->of_node;
|
||
|
|
|
||
|
|
/* ... */
|
||
|
|
|
||
|
|
hpd_gpio = of_get_named_gpio(dp_node, "samsung,hpd-gpio", 0);
|
||
|
|
|
||
|
|
/* ... */
|
||
|
|
|
||
|
|
ret = devm_gpio_request_one(&pdev->dev, hpd_gpio, GPIOF_IN,
|
||
|
|
"hpd_gpio");
|
||
|
|
/* ... */
|
||
|
|
}
|