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# Micro Controller Assist (MCA)

Note This section contains Linux BSP documentation for kernel v4.1. Click here for v4.9 BSP documentation.

The ConnectCore 6UL system-on-module contains an ultra-low power ARM Cortex-M0+ (NXP Kinetis KL03: KL03P24M48SF0) Micro Controller Assist chip. The MCA is connected to the i.MX6UL CPU through the I2C1 port.

The MCA provides the following functionality through a multi-function device driver (MFD):

- Core functionality
  - System-on-module reset logic
  - 32.768 kHz output
  - 1.2 V voltage reference
- Multi-function drivers
  - ADC channels
  - GPIOs
  - Power button
  - Real time clock
  - Watchdog timer

## Kernel configuration

You can manage the MCA driver support through the following kernel configuration option:

- Digi Micro Controller Assist for ConnectCore 6UL (CONFIG_MFD_MCA_CC6UL)

This option enables support for the core functionality of the MCA and is enabled as built-in on the default ConnectCore 6UL kernel configuration file.

Each of the multi-function drivers implement their own kernel options.

## Platform driver mapping

The MCA core driver is located at:

File | Description
--- | ---
drivers/mfd/mca-cc6ul-core.c | ConnectCore 6UL MCA core driver
drivers/mfd/mca-cc6ul-i2c.c | ConnectCore 6UL MCA I2C communication driver
drivers/mfd/mca-cc6ul-irq.c | ConnectCore 6UL MCA interrupt driver

## Device tree bindings and customization

The MCA device tree binding is documented at Documentation/devicetree/bindings/mfd/digi,mca-cc6ul.txt.

The MCA is connected through I2C1 port of the i.MX6UL CPU:

    &i2c1 {

        mca_cc6ul: mca@7e {
            compatible = "digi,mca_cc6ul_dt_ids";
            reg = <0x7e>;
            interrupt-parent = <&gpio5>;
            interrupts = <4 IRQ_TYPE_EDGE_FALLING>;
            interrupt-controller;
            #interrupt-cells = <2>;
            fw-update-gpio = <&gpio4 14 GPIO_ACTIVE_LOW>;
            pinctrl-names = "default";
            pinctrl-0 = <&pinctrl_mca_cc6ul>;

            ...
        };
    };

Note The MCA device tree node has one sub-node for each multi-function driver it supports.

## Functionality

See the following topics for more information on the different functionality the MCA offers:

- Analog-to-Digital Converter (ADC)
- External 32.768 kHz output
- MCA general purpose input/output (GPIO)
- MCA power key input
- MCA real-time clock (RTC)
- Voltage reference 1.2 V
- MCA watchdog

© 2018 Digi International Inc. All rights reserved.
Micro Controller Assist (MCA) updated on 22 January 2018 02:43:37 PM