Re: [PATCH v3 2/3] pmdomain: mediatek: Add support for secure modem power domain control

From: AngeloGioacchino Del Regno

Date: Tue Jul 21 2026 - 05:20:01 EST


On 7/20/26 22:46, Nikolai Burov via B4 Relay wrote:
From: Nikolai Burov <nikolai.burov@xxxxxxxxx>

On recent MediaTek SoCs such as MT6858, the kernel is required to use
a secure monitor call (SMC) to enable or disable the modem power domain.
The power domain control register can be read, but firmware prevents it
from being modified directly. Some other parts of the power sequence,
such as setting the ext_buck_iso register, still need to be performed on
the kernel side.

In preparation for modem support, add a flag to enable this new power
sequence for SoCs that need it. Power domains using this flag are not
expected to configure any bus protection registers, since these are
handled internally by the SMC call.

Signed-off-by: Nikolai Burov <nikolai.burov@xxxxxxxxx>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>