# TLMM Source: [https://docs.qualcomm.com/doc/80-70015-4/topic/tlmm-developer-touchpoints.html](https://docs.qualcomm.com/doc/80-70015-4/topic/tlmm-developer-touchpoints.html) The hardware controls the multiplexing of general-purpose input/output (GPIO) and alternate functions through the top-level mode multiplexer (TLMM). You can configure the GPIOs during the boot process using the DT properties for TLMM. You can edit the following file paths to update the properties on the Linux host machine: - /boot\_images/boot/Settings/Soc/<Chipset>/Core/SocInfra/TLMM/<Chipset>-pinctrl.dtsi - /boot\_images/boot/Settings/Soc/<Chipset>/Core/SocInfra/TLMM/tlmm.dtsi The table lists the properties that describe how to configure the default value of a GPIO based on the requirements of the Qualcomm reference device. Table : TLMM DT properties | Property name | Property description | Data type | Possible values/value range | Device behavior | | --- | --- | --- | --- | --- | | QCOM, sleep-config | GPIO configuration settings as defined in
<Chipset>-pinctrl.dtsi. The configurations
are applied on device boot up. | UINT32 | Pin direction:

GPIO_INPUT – 0x1

GPIO_OUTPUT – 0x2

Pin pull configuration:

GPIO_PULL_DOWN – 0x4

GPIO_PULL_UP – 0x8

GPIO_NO_PULL – 0x10

GPIO_KEEPER – 0x20

Pin output:

GPIO_OUT_LOW – 0x40

GPIO_OUT_HIGH – 0x80

GPIO_PRG_YES – 0x100

GPIO_PRG_NO – 0x000

The default value is GPIO_INPUT
- GPIO_INPUT: Allows the state of an input pin to be read
- GPIO_OUTPUT: Controls the state of an output pin

The default value is GPIO_PULL_DOWN.
- GPIO_PULL_DOWN: Logic 0, consider as connected to
  Ground
- GPIO_PULL_UP: Logic 1, connected to Vdd supply
- GPIO_NO_PULL: Floating/High Impedance state
- GPIO_KEEPER: Maintain the previous state of the GPIO.
  When a SoC enters the deepest power-saving mode,
  this configuration is applied.

The default value is GPIO_OUT_LOW
GPIO_OUT_HIGH: Logic high,
consider as connected to Vdd.

The default value is GPIO_PRG_NO.
GPIO_PRG_YES: Ensures that
any unused GPIOs remain in a low-power state after
bootup

Example:

(GPIO_INPUT | GPIO_PULL_DOWN | GPIO_OUT_LOW | GPIO_PRG_NO) /* PIN 10 */Copy to clipboard | | Compatible | Compatible property contains a read-only string that points to the
compatible chipset. | String | – | Example:

compatible =
"qcom,<chipset>-pinctrl" | | reg | Represents the read only GPIO base address and size. | UINT32 | reg = <0xf100000 0x100000>;Copy to clipboard | In a `reg` property tuple, the first index contains
the base address, and the second index contains the size. Example:
| | ngpios | Number of read only GPIO pins in chipset. | UINT32 | – | Example:

ngpios = <175>;Copy to clipboard | | width | Each GPIO pin has its own set of read only control registers. Width
indicates pin to pin register offset. | – | – | Example:

width = <0x1000>;Copy to clipboard | | id | Hardware instance of read only GPIO pad ID. | UINT32 | – | Example:

id = <0x0>;Copy to clipboard | | version | GPIO read only driver version. Driver 1.0 refers as 0x1. | UINT32 | – | Example:

version = <0x1>;Copy to clipboard | | gpio-controller | Identifier to represent the read only connected device as a GPIO
device. | String | – | – | | phandles for pin configurations | Mux configuration that is used to configure the alternative
functionality of GPIOs. For more information, see [Pin descriptions](https://docs.qualcomm.com/bundle/80-23889-1/resource/80-23889-1_REV_AM_QCS6490_QCS5430_Data_Sheet.pdf). | – | `sdc4_data_1: sdc4_data_1 { mux = <13 3>; };`
| On bootup, the GPIO configures to alternate functionality of
GPIO.
Example:

sdc4_data_1: sdc4_data_1 { mux = <13 3>; };Copy to clipboard

In this example, 13 refers to the GPIO number and 3 indicates the
alternate function selection. | **Parent Topic:** [Interfaces](https://docs.qualcomm.com/doc/80-70015-4/topic/interfaces.html) Last Published: Oct 04, 2024 [Previous Topic PMIC](https://docs.qualcomm.com/bundle/publicresource/80-70015-4/topics/pmic-developer-touchpoints.md) [Next Topic Buses](https://docs.qualcomm.com/bundle/publicresource/80-70015-4/topics/buses.md)