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SOM_62A: Support for CPU core operating at 0.75V instead of 0.85V

Added by rune knutsen over 1 year ago

Short question: Does the SOM_62 and SOM_62A support 0.75V core operation? If yes, how is this selected.
BR Rune Knutsen


Replies (1)

RE: SOM_62A: Support for CPU core operating at 0.75V instead of 0.85V - Added by Jonathan Cormier over 1 year ago

Hi Rune,

The VDD_CORE voltage is set in the device tree and thus configured when the kernel loads.

To switch to 0.75V operation, regulator-min-microvolt and regulator-max-microvolt should be set to 750000.

    tps65219: pmic@30 {
...
        regulators {
            buck1_reg: buck1 {
                regulator-name = "VDD_CORE";
                regulator-min-microvolt = <850000>;
                regulator-max-microvolt = <850000>;
                regulator-boot-on;
                regulator-always-on;
            };

And the following entry should be removed, as the 1.4Ghz mode requires VDD_CORE to be 0.85V


    opp-table {
        /* Add 1.4GHz OPP for am625-sk board. Requires VDD_CORE to be at 0.85V */
        opp-1400000000 {
            opp-hz = /bits/ 64 <1400000000>;
            opp-supported-hw = <0x01 0x0004>;
            clock-latency-ns = <6000000>;
        };
    };

We may eventually move the 1.4Ghz/0.85V OP mode to a device tree overlay as we do plan to support some slower speed grade variants so this will need to be more easily selectable.

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