[PATCH v2 0/4] arm64: dts: allwinner: add Teclast P85T (A523) support
Mikhail Kalashnikov
iuncuim at gmail.com
Wed Sep 30 19:24:11 PDT 2026
This series adds initial support for the Teclast P85T, an 8-inch tablet
based on the Allwinner A523 (sun55i) SoC.
This initial submission enables only what has a binding today.
Display (DE/TCON/DSI), PWM backlight, audio codec, camera (CSI/VIN)
and LRADC keys are deliberately left out, as those blocks is not ready
yet. They will be sent separately.
Patches 1 and 2 overlap with Andre's series
https://lore.kernel.org/linux-sunxi/20260914210115.28151-1-andre.przywara@arm.com/T/#ma8a2554315eccbccdb15ee7ac212a4d0afb45a5c
They are included for compatibility and differ only in the full company
name in the description.
Touchscreen operation requires firmware extracted from the Android
firmware; the file will be added to a public repository later.
The touchscreen values below were obtained experimentally via evtest
and may be inaccurate:
touchscreen-size-x = <1786>;
touchscreen-size-y = <1128>;
With the values below the touchscreen and display coordinates match:
touchscreen-inverted-y;
touchscreen-swapped-x-y;
The battery values are taken from the battery label
(5000 mAh, 4.4 V max charge) and the Android DTB
(pmu_runtime_chgcur = <0x320>, i.e. 800 mA safe charge current).
U-Boot support requires an LPDDR3 driver for the A523, which will be
sent a bit later.
A ready-to-use image with working display, audio and touchscreen can be
found on the Manjaro forum. Patches will be added as other contributors
add their parts.
Changes since v1 [1]:
- Added Reviewed-by from Andre Przywara for patch 3;
- Replaced the dummy 1.8V pio-18 regulator with the real PMIC rails;
- Dropped reg_dcdc4: no consumers, the kernel would turn it off;
- Dropped AXP323 aldo1/dldo1: no consumers - the board is verified
to work with both rails disabled;
- Renamed bldo2 to "vcc-dram-1v8" (needs to be kept always-on).
- Renamed cldo1 from "vcc-codec-sd" to "vcc-codec-mmc";
- Described AXP323 dcdc3 as the RISC-V management core supply, like
on the other A523 boards;
- USB: removed the inbound 5V rail from usb0_vbus-supply and dropped
ehci0/ohci0; the port is works like peripheral-only, using
usb0_vbus_det-gpios for VBUS sensing;
- Dropped the iio-hwmon node due to invalid values;
- Commit message wording: those blocks "don't have a binding yet".
[1] https://lore.kernel.org/linux-sunxi/20260918165414.1129076-1-iuncuim@gmail.com/
Based on 7.3-rc3.
Mikhail Kalashnikov (4):
dt-bindings: vendor-prefixes: Add vendor prefix for Teclast
dt-bindings: arm: sunxi: Add Teclast P85T tablet
arm64: dts: allwinner: sun55i-a523: add I2C0 and I2C1 pin groups
arm64: dts: allwinner: add Teclast P85T tablet
.../devicetree/bindings/arm/sunxi.yaml | 5 +
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
arch/arm64/boot/dts/allwinner/Makefile | 1 +
.../allwinner/sun55i-a523-teclast-p85t.dts | 386 ++++++++++++++++++
.../arm64/boot/dts/allwinner/sun55i-a523.dtsi | 18 +
5 files changed, 412 insertions(+)
create mode 100644 arch/arm64/boot/dts/allwinner/sun55i-a523-teclast-p85t.dts
--
2.55.0
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