Download raw body.
ims(4) touchscreen support for the SGB4E
On Sat, 23 May 2026 17:01:50 +0200,
Marcus Glocker <marcus@nazgul.ch> wrote:
>
> This supersedes the earlier imt(4) touchscreen diff, which regressed
> kirill's Honor panel.
>
> The difference is that we enable the Samsung Galaxy Book4 Edge
> touchscreen support with ims(4), not imt(4), which has less impact,
> and introduces less risk for regression:
>
> - The ihidev(4) change resolves the in-tree polled finger-up TODO
> and is child-agnostic. This touchscreen remains polled, until we
> can find out which is the correct GPIO for enabling interrupts on
> this device.
>
> - The hidms gate is edge-not-level so it spares pens and never touches
> relative mice.
>
> Together with the DTS diff (not changed from last time) to power-on
> the touchpanel device, this makes the touchscreen work on the
> Samsung Galaxy Book4 Edge.
>
> I would appreciate some regression testing from people who are using
> ims(4) devices.
>
Tested on
1. Huawei Matebook X 2020 where I have 3 ims devices
ims0 at ihidev0 reportid 1: 2 buttons
wsmouse1 at ims0 mux 0
ims1 at ihidev0 reportid 14: 0 buttons
wsmouse2 at ims1 mux 0
ims2 at ihidev1 reportid 1: 1 button, tip
wsmouse3 at ims2 mux 0
2. Honor Magicbook 14 Snapdragon with
ims0 at ihidev0 reportid 1: 1 button, tip
wsmouse0 at ims0 mux 0
ims1 at ihidev2 reportid 1: 3 buttons, Z dir
wsmouse2 at ims1 mux 0
No regression: touchscreen, touchpad with multitouch works on both laptops.
>
> Index: sys/dev/hid/hidms.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/hid/hidms.c,v
> diff -u -p -u -p -r1.11 hidms.c
> --- sys/dev/hid/hidms.c 10 May 2024 10:49:10 -0000 1.11
> +++ sys/dev/hid/hidms.c 23 May 2026 14:30:24 -0000
> @@ -533,7 +533,7 @@ hidms_input(struct hidms *ms, uint8_t *d
> {
> int dx, dy, dz, dw;
> u_int32_t buttons = 0;
> - int i, s;
> + int i, s, released;
>
> DPRINTFN(5,("hidms_input: len=%d\n", len));
>
> @@ -595,17 +595,26 @@ hidms_input(struct hidms *ms, uint8_t *d
> buttons != ms->sc_buttons) {
> DPRINTFN(10, ("hidms_input: x:%d y:%d z:%d w:%d buttons:0x%x\n",
> dx, dy, dz, dw, buttons));
> + released = (ms->sc_buttons != 0 && buttons == 0);
> ms->sc_buttons = buttons;
> if (ms->sc_wsmousedev != NULL) {
> s = spltty();
> + /*
> + * A polled touchscreen reports finger-up as a zeroed
> + * packet; emitting its (0,0) as an absolute position
> + * would snap the pointer to the corner. On a button
> + * release edge, hold the last position instead.
> + */
> if (ms->sc_flags & HIDMS_ABSX) {
> - wsmouse_set(ms->sc_wsmousedev,
> - WSMOUSE_ABS_X, dx, 0);
> + if (!released)
> + wsmouse_set(ms->sc_wsmousedev,
> + WSMOUSE_ABS_X, dx, 0);
> dx = 0;
> }
> if (ms->sc_flags & HIDMS_ABSY) {
> - wsmouse_set(ms->sc_wsmousedev,
> - WSMOUSE_ABS_Y, dy, 0);
> + if (!released)
> + wsmouse_set(ms->sc_wsmousedev,
> + WSMOUSE_ABS_Y, dy, 0);
> dy = 0;
> }
> WSMOUSE_INPUT(ms->sc_wsmousedev,
> Index: sys/dev/i2c/ihidev.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/i2c/ihidev.c,v
> diff -u -p -u -p -r1.43 ihidev.c
> --- sys/dev/i2c/ihidev.c 23 May 2026 11:10:57 -0000 1.43
> +++ sys/dev/i2c/ihidev.c 23 May 2026 14:30:24 -0000
> @@ -142,6 +142,7 @@ ihidev_attach(struct device *parent, str
> sc->sc_tag = ia->ia_tag;
> sc->sc_addr = ia->ia_addr;
> sc->sc_hid_desc_addr = ia->ia_size;
> + sc->sc_lastrepid = -1;
>
> if (ihidev_hid_command(sc, I2C_HID_CMD_DESCR, NULL) ||
> ihidev_hid_desc_parse(sc)) {
> @@ -159,10 +160,13 @@ ihidev_attach(struct device *parent, str
>
> /* find largest report size and allocate memory for input buffer */
> sc->sc_isize = letoh16(sc->hid_desc.wMaxInputLength);
> + sc->sc_repsizes = mallocarray(sc->sc_nrepid, sizeof(int),
> + M_DEVBUF, M_WAITOK | M_ZERO);
> for (repid = 0; repid < sc->sc_nrepid; repid++) {
> repsz = hid_report_size(sc->sc_report, sc->sc_reportlen,
> hid_input, repid);
> repsizes[repid] = repsz;
> + sc->sc_repsizes[repid] = repsz;
> if (repsz > sc->sc_isize)
> sc->sc_isize = repsz;
> if (repsz != 0)
> @@ -255,6 +259,9 @@ ihidev_detach(struct device *self, int f
> if (sc->sc_report != NULL)
> free(sc->sc_report, M_DEVBUF, sc->sc_reportlen);
>
> + if (sc->sc_repsizes != NULL)
> + free(sc->sc_repsizes, M_DEVBUF, sc->sc_nrepid * sizeof(int));
> +
> return (0);
> }
>
> @@ -718,10 +725,21 @@ ihidev_intr(void *arg)
> psize = sc->sc_ibuf[0] | sc->sc_ibuf[1] << 8;
> if (psize <= 2 || psize > sc->sc_isize) {
> if (sc->sc_poll) {
> - /*
> - * TODO: all fingers are up, should we pass to hid
> - * layer?
> - */
> + /* empty packet: hand the last subdev a zeroed report
> + * once so it releases its contacts (polled finger-up) */
> + int lrep = sc->sc_lastrepid;
> + int rsz;
> +
> + if (lrep >= 0 && lrep < sc->sc_nrepid &&
> + (scd = sc->sc_subdevs[lrep]) != NULL &&
> + (scd->sc_state & IHIDEV_OPEN) && !sc->sc_dying) {
> + rsz = sc->sc_repsizes[lrep];
> + if (rsz > 0 && rsz <= sc->sc_isize) {
> + memset(sc->sc_ibuf, 0, rsz);
> + scd->sc_intr(scd, sc->sc_ibuf, rsz);
> + }
> + sc->sc_lastrepid = -1;
> + }
> sc->sc_fastpoll = 0;
> goto more_polling;
> } else
> @@ -770,8 +788,10 @@ ihidev_intr(void *arg)
> return (1);
> }
>
> - if (!sc->sc_dying)
> + if (!sc->sc_dying) {
> + sc->sc_lastrepid = rep;
> scd->sc_intr(scd, p, psize);
> + }
>
> if (sc->sc_poll && (fast != sc->sc_fastpoll)) {
> DPRINTF(("%s: %s->%s polling\n", sc->sc_dev.dv_xname,
> Index: sys/dev/i2c/ihidev.h
> ===================================================================
> RCS file: /cvs/src/sys/dev/i2c/ihidev.h,v
> diff -u -p -u -p -r1.11 ihidev.h
> --- sys/dev/i2c/ihidev.h 7 Jan 2025 19:26:14 -0000 1.11
> +++ sys/dev/i2c/ihidev.h 23 May 2026 14:30:24 -0000
> @@ -85,6 +85,8 @@ struct ihidev_softc {
>
> u_int sc_isize;
> u_char *sc_ibuf;
> + int sc_lastrepid; /* report id of last non-empty input */
> + int *sc_repsizes; /* per-report input size, for poll path */
>
> int sc_refcnt;
>
> Index: sysutils/firmware/arm64-qcom-dtb/Makefile
> ===================================================================
> RCS file: /cvs/ports/sysutils/firmware/arm64-qcom-dtb/Makefile,v
> diff -u -p -u -p -r1.29 Makefile
> --- sysutils/firmware/arm64-qcom-dtb/Makefile 19 May 2026 04:47:35 -0000 1.29
> +++ sysutils/firmware/arm64-qcom-dtb/Makefile 21 May 2026 19:32:13 -0000
> @@ -1,6 +1,6 @@
> FW_DRIVER= arm64-qcom-dtb
> FW_VER= 2.7
> -REVISION= 1
> +REVISION= 2
>
> DISTNAME= devicetree-rebasing-6.17-dts
>
> Index: sysutils/firmware/arm64-qcom-dtb/patches/patch-src_arm64_qcom_x1e80100-samsung-galaxy-book4-edge_dts
> ===================================================================
> RCS file: /cvs/ports/sysutils/firmware/arm64-qcom-dtb/patches/patch-src_arm64_qcom_x1e80100-samsung-galaxy-book4-edge_dts,v
> diff -u -p -u -p -r1.3 patch-src_arm64_qcom_x1e80100-samsung-galaxy-book4-edge_dts
> --- sysutils/firmware/arm64-qcom-dtb/patches/patch-src_arm64_qcom_x1e80100-samsung-galaxy-book4-edge_dts 19 May 2026 04:47:35 -0000 1.3
> +++ sysutils/firmware/arm64-qcom-dtb/patches/patch-src_arm64_qcom_x1e80100-samsung-galaxy-book4-edge_dts 21 May 2026 19:32:13 -0000
> @@ -1,7 +1,7 @@
> Index: src/arm64/qcom/x1e80100-samsung-galaxy-book4-edge.dts
> --- src/arm64/qcom/x1e80100-samsung-galaxy-book4-edge.dts.orig
> +++ src/arm64/qcom/x1e80100-samsung-galaxy-book4-edge.dts
> -@@ -0,0 +1,977 @@
> +@@ -0,0 +1,988 @@
> +// SPDX-License-Identifier: BSD-3-Clause
> +/*
> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
> @@ -10,6 +10,7 @@ Index: src/arm64/qcom/x1e80100-samsung-g
> +/dts-v1/;
> +
> +#include <dt-bindings/gpio/gpio.h>
> ++#include <dt-bindings/pinctrl/qcom,pmic-gpio.h>
> +#include <dt-bindings/regulator/qcom,rpmh-regulator.h>
> +
> +#include "x1e80100.dtsi"
> @@ -181,6 +182,24 @@ Index: src/arm64/qcom/x1e80100-samsung-g
> + regulator-always-on;
> + regulator-boot-on;
> + };
> ++
> ++ /* 3V3 rail powering the touchscreen, gated by pm8550ve_8 gpio6 */
> ++ vreg_misc_3p3: regulator-misc-3p3 {
> ++ compatible = "regulator-fixed";
> ++
> ++ regulator-name = "VREG_MISC_3P3";
> ++ regulator-min-microvolt = <3300000>;
> ++ regulator-max-microvolt = <3300000>;
> ++
> ++ gpio = <&pm8550ve_8_gpios 6 GPIO_ACTIVE_HIGH>;
> ++ enable-active-high;
> ++
> ++ pinctrl-0 = <&misc_3p3_reg_en>;
> ++ pinctrl-names = "default";
> ++
> ++ regulator-boot-on;
> ++ regulator-always-on;
> ++ };
> +};
> +
> +&apps_rsc {
> @@ -572,26 +591,33 @@ Index: src/arm64/qcom/x1e80100-samsung-g
> + };
> +};
> +
> ++/* GXTP7936 touchscreen, powered by vreg_misc_3p3. No usable IRQ pin
> ++ * known, so ihidev(4) polls. */
> +&i2c8 {
> + clock-frequency = <400000>;
> +
> -+ status = "disabled";
> ++ status = "okay";
> +
> + touchscreen@5d {
> + compatible = "hid-over-i2c";
> + reg = <0x5d>;
> +
> + hid-descr-addr = <0x1>;
> -+ /*
> -+ * Pin 51 is creating an interrupt storm. Hence, choosing
> -+ * some other pin which just does nothing. But obviously,
> -+ * the touchscreen won't work for now.
> -+ */
> -+ //interrupts-extended = <&tlmm 51 IRQ_TYPE_LEVEL_LOW>;
> -+ interrupts-extended = <&tlmm 33 IRQ_TYPE_LEVEL_LOW>;
> +
> -+ pinctrl-0 = <&ts0_default>;
> -+ pinctrl-names = "default";
> ++ vdd-supply = <&vreg_misc_3p3>;
> ++ };
> ++};
> ++
> ++&pm8550ve_8_gpios {
> ++ misc_3p3_reg_en: misc-3p3-reg-en-state {
> ++ pins = "gpio6";
> ++ function = "normal";
> ++ bias-disable;
> ++ input-disable;
> ++ output-enable;
> ++ drive-push-pull;
> ++ power-source = <1>; /* 1.8 V */
> ++ qcom,drive-strength = <PMIC_GPIO_STRENGTH_LOW>;
> + };
> +};
> +
> @@ -863,21 +889,6 @@ Index: src/arm64/qcom/x1e80100-samsung-g
> + pins = "gpio3";
> + function = "gpio";
> + bias-disable;
> -+ };
> -+
> -+ ts0_default: ts0-default-state {
> -+ int-n-pins {
> -+ pins = "gpio51";
> -+ function = "gpio";
> -+ bias-disable;
> -+ };
> -+
> -+ reset-n-pins {
> -+ pins = "gpio48";
> -+ function = "gpio";
> -+ output-high;
> -+ drive-strength = <16>;
> -+ };
> + };
> +
> + wcd_default: wcd-reset-n-active-state {
--
wbr, Kirill
ims(4) touchscreen support for the SGB4E