Re: [PATCH] Input: tca8418_keypad - enable overflow mode per datasheet (SCPS215G)
From: Dmitry Torokhov
Date: Wed Jul 15 2026 - 17:02:02 EST
On Fri, May 29, 2026 at 09:39:00AM +0800, Zhian Liang wrote:
> The driver currently sets only the overflow interrupt enable bit
> (OVR_FLOW_IEN) in the configuration register, leaving the overflow
> mode bit (OVR_FLOW_M) at its default value of 0.
>
> According to the TCA8418 datasheet (SCPS215G, Section 8.6.4.1
> "Overflow Errata - Description"), both OVR_FLOW_M (Bit_5) and
> OVR_FLOW_IEN (Bit_3) must be set high for the overflow interrupt
> to be generated. If only OVR_FLOW_IEN is set, FIFO overflow events
> are silently lost without notifying the host.
>
> Fix this by setting OVR_FLOW_M alongside OVR_FLOW_IEN in the
> configuration register.
>
> Note: I do not have access to hardware to test this change.
> Testing by generating 11+ key events without reading the FIFO
> would be appreciated. Full handling of overflow events in the
> interrupt handler is left for future improvement.
>
> Signed-off-by: Zhian Liang <liangzhan5dev@xxxxxxxxx>
Applied, thank you.
--
Dmitry