Micro Controller Assist (MCA)

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: