[PATCH 0/5] Minor Imagis driver refactoring and support for IST4050
From: Markuss Broks via B4 Relay
Date: Fri Aug 21 2026 - 17:30:57 EST
The Imagis IST4050 is a touchscreen IC of the IST40xx family. It shares
the register interface, the power-up sequence and the coordinate format
with IST3038C, but reports touches differently: instead of a per-index
contact snapshot paired with a "pressed" bitmask in the interrupt
message, the controller exposes one record per contact, 8 bytes apart,
carrying a hardware-assigned touch ID and a press/release event type in
its upper byte. The bits which hold the contact area on IST3038C hold
the event type on these chips, and no contact area is available in the
coordinate word.
Patch 1 documents the IST4050 compatible. Patch 2 stops reporting
coordinates of released contacts; besides avoiding pointless events on
slots which have just been deactivated, this is required for IST40xx,
where release records must not be parsed for the contact area. Patch 3
replaces the protocol_b flag with an enum which describes each touch
reporting format, patch 4 adds support for the IST40xx reporting format
and patch 5 wires the chip up.
The series has been tested on IST4050 (Samsung Galaxy A70 SM-A705FN).
No functional change is intended for the already-supported chips,
except that coordinates are no longer reported for contacts being released.
Signed-off-by: Markuss Broks <markuss.broks@xxxxxxxxx>
---
Markuss Broks (5):
dt-bindings: input: touchscreen: imagis: add compatible for IST4050
Input: imagis - do not report coordinates of released contacts
Input: imagis - replace the protocol_b flag with a protocol enum
Input: imagis - add support for the IST40xx touch reporting format
Input: imagis - add support for IST4050
.../input/touchscreen/imagis,ist3038c.yaml | 3 +-
drivers/input/touchscreen/Kconfig | 2 +-
drivers/input/touchscreen/imagis.c | 83 +++++++++++++++++++---
3 files changed, 76 insertions(+), 12 deletions(-)
---
base-commit: 415606a7be939835db9b0d6b711887586646346d
change-id: 20260820-imagis-40xx-62fd11f8d7f8
Best regards,
--
Markuss Broks <markuss.broks@xxxxxxxxx>