[PATCH 0/1] Input: Add TouchNetix aXiom touchscreen driver

[PATCH 0/1] Input: Add TouchNetix aXiom touchscreen driver

[AThomas63]

A Summary of the added features:
 - Add input driver support for TouchNetix aXiom touchscreen controller 
using either I2C or SPI.
 - Support ABS_MT touch reports in axiom_process_u41_report().
 - Support both polling and interrupt mode (trigger low).
 - Add basic documentation and provide example device tree bindings.
 - Provide the basic structure to add firmware and config download in
the future via both I2C and SPI.

I understand the process is already under way to add a driver to support 
aXiom by Marco at Pengutronix.
I think it would be most useful for us to attempt to combine this patch
in order to support both his changes for config/firmware download and 
the patch here for SPI support along with I2C. I would be happy to help 
with this process.
This would allow TouchNetix to support a broader range of users of the
aXiom device family.

I also have a device tree binding however I have not added it sincec
from my understanding this should go in a different patch:
Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml
 
My apologies if there are any obvious mistakes in this patch, this is the
first patch that I have submitted.

Many thanks for your time,
Andrew Thomas

AThomas63 (1):
  Adding support for aXiom touchscreen controller

 drivers/input/touchscreen/Kconfig      |  30 ++
 drivers/input/touchscreen/Makefile     |   3 +
 drivers/input/touchscreen/axiom_core.c | 482 +++++++++++++++++++++++++
 drivers/input/touchscreen/axiom_core.h | 128 +++++++
 drivers/input/touchscreen/axiom_i2c.c  | 152 ++++++++
 drivers/input/touchscreen/axiom_spi.c  | 159 ++++++++
 6 files changed, 954 insertions(+)
 create mode 100644 drivers/input/touchscreen/axiom_core.c
 create mode 100644 drivers/input/touchscreen/axiom_core.h
 create mode 100644 drivers/input/touchscreen/axiom_i2c.c
 create mode 100644 drivers/input/touchscreen/axiom_spi.c

-- 
2.43.0

[PATCH 1/1] Adding support for aXiom touchscreen controller

[AThomas63]

Signed-off-by: AThomas63 <andrew.thomas@touchnetix.com>
---
 drivers/input/touchscreen/Kconfig      |  30 ++
 drivers/input/touchscreen/Makefile     |   3 +
 drivers/input/touchscreen/axiom_core.c | 482 +++++++++++++++++++++++++
 drivers/input/touchscreen/axiom_core.h | 128 +++++++
 drivers/input/touchscreen/axiom_i2c.c  | 152 ++++++++
 drivers/input/touchscreen/axiom_spi.c  | 159 ++++++++
 6 files changed, 954 insertions(+)
 create mode 100644 drivers/input/touchscreen/axiom_core.c
 create mode 100644 drivers/input/touchscreen/axiom_core.h
 create mode 100644 drivers/input/touchscreen/axiom_i2c.c
 create mode 100644 drivers/input/touchscreen/axiom_spi.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 7d5b72ee07fa..f2b4fb317bdd 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -162,6 +162,36 @@ config TOUCHSCREEN_AUO_PIXCIR
 	  To compile this driver as a module, choose M here: the
 	  module will be called auo-pixcir-ts.
 
+config TOUCHSCREEN_AXIOM_CORE
+	tristate "TouchNetix Axiom touchscreen"
+	help
+	  Say Y here if you have an Axiom touchscreen connected
+	  to your system. You will also need to select appropriate
+	  bus connection below.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called axiom_core.
+
+config TOUCHSCREEN_AXIOM_I2C
+	tristate "support I2C bus connection"
+	depends on TOUCHSCREEN_AXIOM_CORE && I2C
+	help
+	  Say Y here if the touchscreen is connected via I2C bus.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called axiom_spi.
+
+config TOUCHSCREEN_AXIOM_SPI
+	tristate "support SPI bus connection"
+	depends on TOUCHSCREEN_AXIOM_CORE && SPI
+	help
+	  Say Y here if the touchscreen is connected via SPI bus.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called axiom_spi.
+
 config TOUCHSCREEN_BU21013
 	tristate "BU21013 based touch panel controllers"
 	depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index ab9abd151078..9b7d572c4589 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -19,6 +19,9 @@ obj-$(CONFIG_TOUCHSCREEN_APPLE_Z2)	+= apple_z2.o
 obj-$(CONFIG_TOUCHSCREEN_AR1021_I2C)	+= ar1021_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT)	+= atmel_mxt_ts.o
 obj-$(CONFIG_TOUCHSCREEN_AUO_PIXCIR)	+= auo-pixcir-ts.o
+obj-$(CONFIG_TOUCHSCREEN_AXIOM_CORE)	+= axiom_core.o
+obj-$(CONFIG_TOUCHSCREEN_AXIOM_I2C)	+= axiom_i2c.o
+obj-$(CONFIG_TOUCHSCREEN_AXIOM_SPI)	+= axiom_spi.o
 obj-$(CONFIG_TOUCHSCREEN_BU21013)	+= bu21013_ts.o
 obj-$(CONFIG_TOUCHSCREEN_BU21029)	+= bu21029_ts.o
 obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318)	+= chipone_icn8318.o
diff --git a/drivers/input/touchscreen/axiom_core.c b/drivers/input/touchscreen/axiom_core.c
new file mode 100644
index 000000000000..7983effe40f7
--- /dev/null
+++ b/drivers/input/touchscreen/axiom_core.c
@@ -0,0 +1,482 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TouchNetix aXiom Touchscreen Driver
+ *
+ * Copyright (C) 2020-2026 TouchNetix Ltd.
+ *
+ * Author(s): Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
+ *            Pedro Torruella <pedro.torruella@touchnetix.com>
+ *            Bart Prescott <bartp@baasheep.co.uk>
+ *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
+ *            Andrew Thomas <andrew.thomas@touchnetix.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+
+// #define DEBUG // Enable debug messages
+
+#include <linux/device.h>
+#include <linux/input/mt.h>
+#include <linux/crc16.h>
+#include <linux/property.h>
+#include <linux/interrupt.h>
+#include <linux/unaligned.h>
+#include "axiom_core.h"
+
+/* u31 device info masks */
+#define AX_DEV_ID_MASK GENMASK(14, 0)
+#define AX_MODE BIT(15)
+#define AX_FW_REV_MINOR_MASK GENMASK(7, 0)
+#define AX_FW_REV_MAJOR_MASK GENMASK(15, 8)
+#define AX_VARIANT_MASK GENMASK(5, 0)
+#define AX_FW_STATUS BIT(7)
+#define AX_TCP_REV_MASK GENMASK(15, 8)
+#define AX_BOOT_REV_MINOR_MASK GENMASK(7, 0)
+#define AX_BOOT_REV_MAJOR_MASK GENMASK(15, 8)
+#define AX_NUM_USAGES_MASK GENMASK(7, 0)
+#define AX_SILICON_REV_MASK GENMASK(11, 8)
+#define AX_RUNTIME_FW_PATCH_MASK GENMASK(15, 12)
+
+/* u31 usage table entry masks */
+#define AX_U31_USAGE_NUM_MASK GENMASK(7, 0)
+#define AX_U31_START_PAGE_MASK GENMASK(15, 8)
+#define AX_U31_NUM_PAGES_MASK GENMASK(7, 0)
+#define AX_U31_MAX_OFFSET_MASK GENMASK(14, 8)
+#define AX_U31_OFFSET_TYPE_BIT BIT(15)
+#define AX_U31_UIF_REV_MASK GENMASK(7, 0)
+#define AX_U31_USAGE_TYPE_MASK GENMASK(15, 8)
+
+/* u34 report masks */
+#define AX_U34_LEN_MASK GENMASK(6, 0)
+#define AX_U34_OVERFLOW BIT(7)
+#define AX_U34_USAGE_MASK GENMASK(15, 8)
+#define AX_U34_PAYLOAD_BUFFER 2
+
+/* u41 report masks */
+#define AX_U41_PRESENT_MASK GENMASK(9, 0)
+#define U41_X_Y_OFFSET (2)
+#define U41_COORD_SIZE (4)
+#define U41_Z_OFFSET (42)
+
+static const char *const fw_variants[] = { "3D", "2D", "FORCE",
+					   "0D", "XL", "TOUCHPAD" };
+
+static int axiom_set_capabilities(struct input_dev *input_dev)
+{
+	input_dev->name = "TouchNetix aXiom Touchscreen";
+	input_dev->phys = "input/axiom_ts";
+
+	// Single Touch
+	input_set_abs_params(input_dev, ABS_X, 0, 65535, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, 65535, 0, 0);
+
+	// Multi Touch
+	// Min, Max, Fuzz (expected noise in px, try 4?) and Flat
+	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
+	// Min, Max, Fuzz (expected noise in px, try 4?) and Flat
+	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
+
+	input_mt_init_slots(input_dev, U41_MAX_TARGETS, INPUT_MT_DIRECT);
+
+	return 0;
+}
+
+static struct u31_usage_entry *usage_find_entry(struct axiom *ax, u16 usage)
+{
+	u16 i;
+
+	for (i = 0; i < ax->dev_info.num_usages; i++) {
+		if (ax->usage_table[i].usage_num == usage)
+			return &ax->usage_table[i];
+	}
+
+	pr_err("aXiom-core: Usage u%02x not found in usage table\n", usage);
+	return ERR_PTR(-EINVAL);
+}
+
+static void axiom_unpack_device_info(const u8 *buf,
+				     struct axiom_device_info *info)
+{
+	u16 w;
+
+	w = get_unaligned_le16(buf);
+	info->device_id = FIELD_GET(AX_DEV_ID_MASK, w);
+	info->mode = !!(w & AX_MODE);
+
+	w = get_unaligned_le16(buf + 2);
+	info->runtime_fw_rev_minor = FIELD_GET(AX_FW_REV_MINOR_MASK, w);
+	info->runtime_fw_rev_major = FIELD_GET(AX_FW_REV_MAJOR_MASK, w);
+
+	w = get_unaligned_le16(buf + 4);
+	info->device_build_variant = FIELD_GET(AX_VARIANT_MASK, w);
+	info->runtime_fw_status = !!(w & AX_FW_STATUS);
+	info->tcp_revision = FIELD_GET(AX_TCP_REV_MASK, w);
+
+	w = get_unaligned_le16(buf + 6);
+	info->bootloader_fw_rev_minor = FIELD_GET(AX_BOOT_REV_MINOR_MASK, w);
+	info->bootloader_fw_rev_major = FIELD_GET(AX_BOOT_REV_MAJOR_MASK, w);
+
+	info->jedec_id = get_unaligned_le16(buf + 8);
+
+	w = get_unaligned_le16(buf + 10);
+	info->num_usages = FIELD_GET(AX_NUM_USAGES_MASK, w);
+	info->silicon_revision = FIELD_GET(AX_SILICON_REV_MASK, w);
+	info->runtime_fw_rev_patch = FIELD_GET(AX_RUNTIME_FW_PATCH_MASK, w);
+}
+
+static void axiom_unpack_usage_table(u8 *buf, struct axiom *ax)
+{
+	u8 *ptr;
+	struct u31_usage_entry *entry;
+	int i;
+	u16 w;
+	u16 report_len;
+
+	for (i = 0; i < ax->dev_info.num_usages && i < U31_MAX_USAGES; i++) {
+		entry = &ax->usage_table[i];
+		/* Calculate offset for this specific entry */
+		ptr = buf + (i * SIZE_U31_USAGE_ENTRY);
+
+		w = get_unaligned_le16(ptr);
+		entry->usage_num = FIELD_GET(AX_U31_USAGE_NUM_MASK, w);
+		entry->start_page = FIELD_GET(AX_U31_START_PAGE_MASK, w);
+
+		w = get_unaligned_le16(ptr + 2);
+		entry->num_pages = FIELD_GET(AX_U31_NUM_PAGES_MASK, w);
+		entry->max_offset = FIELD_GET(AX_U31_MAX_OFFSET_MASK, w);
+		entry->offset_type = !!(w & AX_U31_OFFSET_TYPE_BIT);
+
+		w = get_unaligned_le16(ptr + 4);
+		entry->uifrevision = FIELD_GET(AX_U31_UIF_REV_MASK, w);
+		entry->usage_type = FIELD_GET(AX_U31_USAGE_TYPE_MASK, w);
+
+		// Convert words to bytes
+		report_len = (entry->max_offset + 1) * 2;
+		if ((entry->usage_type == REPORT) &&
+		    (report_len > ax->max_report_len)) {
+			ax->max_report_len = report_len;
+		}
+	}
+}
+
+static int axiom_init_dev_info(struct axiom *ax)
+{
+	int i;
+	struct u31_usage_entry *u;
+	int err;
+	const char *variant_str;
+
+	/* Read page 0 of u31 */
+	err = ax->bus_ops->read(ax->dev, 0x0, SIZE_U31_DEVICE_INFO,
+				ax->read_buf);
+	if (err)
+		return -EIO;
+
+	axiom_unpack_device_info(ax->read_buf, &ax->dev_info);
+
+	if (ax->dev_info.device_build_variant < ARRAY_SIZE(fw_variants)) {
+		variant_str = fw_variants[ax->dev_info.device_build_variant];
+	} else {
+		variant_str = "UNKNOWN";
+	}
+	char silicon_rev = (char)(0x41 + ax->dev_info.silicon_revision);
+
+	dev_info(ax->dev, "Firmware Info:\n");
+	dev_info(ax->dev, "  BL Mode     : %u\n", ax->dev_info.mode);
+	dev_info(ax->dev, "  Device ID   : %04x\n", ax->dev_info.device_id);
+	dev_info(ax->dev, "  FW Revision : %u.%u.%u-%s %s\n",
+		 ax->dev_info.runtime_fw_rev_major,
+		 ax->dev_info.runtime_fw_rev_minor,
+		 ax->dev_info.runtime_fw_rev_patch,
+		 (ax->dev_info.runtime_fw_status == 0) ? "eng" : "prod",
+		 variant_str);
+	dev_info(ax->dev, "  BL Revision : %02x.%02x\n",
+		 ax->dev_info.bootloader_fw_rev_major,
+		 ax->dev_info.bootloader_fw_rev_minor);
+	dev_info(ax->dev, "  Silicon     : 0x%04X (Rev %c)\n",
+		 ax->dev_info.jedec_id, silicon_rev);
+	dev_info(ax->dev, "  Num Usages  : %u\n", ax->dev_info.num_usages);
+
+	if (ax->dev_info.num_usages > U31_MAX_USAGES) {
+		dev_err(ax->dev,
+			"Num usages (%u) exceeds maximum supported (%u)\n",
+			ax->dev_info.num_usages, U31_MAX_USAGES);
+		return -EINVAL;
+	}
+
+	/* Read the second page of u31 to get the usage table */
+	err = ax->bus_ops->read(ax->dev, 0x100,
+				sizeof(ax->usage_table[0]) *
+					ax->dev_info.num_usages,
+				ax->read_buf);
+	if (err)
+		return -EIO;
+
+	axiom_unpack_usage_table(ax->read_buf, ax);
+
+	dev_info(ax->dev, "Usage Table:\n");
+	for (i = 0; i < ax->dev_info.num_usages; i++) {
+		u = &ax->usage_table[i];
+
+		dev_info(
+			ax->dev,
+			"  Usage: u%02x  Rev: %3u  Page: 0x%02x00  Num Pages: %3u\n",
+			u->usage_num, u->uifrevision, u->start_page,
+			u->num_pages);
+	}
+	dev_info(ax->dev, "Max Report Length: %u\n", ax->max_report_len);
+
+	if (ax->max_report_len > AXIOM_MAX_READ_SIZE) {
+		dev_err(ax->dev,
+			"aXiom maximum report length (%u) greater than allocated buffer size (%u).",
+			ax->max_report_len, AXIOM_MAX_READ_SIZE);
+		return -EINVAL;
+	}
+
+	/* Set u34 address to allow direct access to report reading address */
+	u = usage_find_entry(ax, 0x34);
+	if (IS_ERR(u))
+		return PTR_ERR(u);
+	ax->u34_address = u->start_page << 8;
+
+	return 0;
+}
+
+static int axiom_process_u41_report(struct axiom *ax, u8 *report)
+{
+	int i;
+	u16 target_present;
+	bool active;
+	u8 offset;
+	enum u41_target_state_e state;
+	u16 x;
+	u16 y;
+	s8 z;
+
+	target_present =
+		FIELD_GET(AX_U41_PRESENT_MASK, get_unaligned_le16(&report[0]));
+
+	for (i = 0; i < U41_MAX_TARGETS; i++) {
+		active = !!((target_present >> i) & 1);
+
+		offset = U41_X_Y_OFFSET + (i * U41_COORD_SIZE);
+		x = get_unaligned_le16(&report[offset]);
+		y = get_unaligned_le16(&report[offset + 2]);
+		z = report[U41_Z_OFFSET + i];
+
+		if (!active)
+			state = Target_State_Not_Present;
+		else if (z >= 0)
+			state = Target_State_Touching;
+		else if ((z > U41_PROX_LEVEL) && (z < 0))
+			state = Target_State_Hover;
+		else if (z == U41_PROX_LEVEL)
+			state = Target_State_Prox;
+		else
+			state = Target_State_Not_Present;
+
+		dev_dbg(ax->dev, "Target %d: x=%u y=%u z=%d present=%d\n", i, x,
+			y, z, active);
+
+		switch (state) {
+		case Target_State_Not_Present:
+		case Target_State_Prox:
+
+			input_mt_slot(ax->input, i);
+			input_mt_report_slot_inactive(ax->input);
+			break;
+
+		case Target_State_Hover:
+		case Target_State_Touching:
+
+			input_mt_slot(ax->input, i);
+			input_report_abs(ax->input, ABS_MT_TRACKING_ID, i);
+			input_report_abs(ax->input, ABS_MT_POSITION_X, x);
+			input_report_abs(ax->input, ABS_MT_POSITION_Y, y);
+
+			if (state == Target_State_Touching) {
+				input_report_abs(ax->input, ABS_MT_DISTANCE, 0);
+				input_report_abs(ax->input, ABS_MT_PRESSURE, z);
+			} else { /* Hover */
+				input_report_abs(ax->input, ABS_MT_DISTANCE, -z);
+				input_report_abs(ax->input, ABS_MT_PRESSURE, 0);
+			}
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	input_mt_sync_frame(ax->input);
+	input_sync(ax->input);
+
+	return 0;
+}
+
+static int axiom_process_report(struct axiom *ax, u8 *report)
+{
+	int err;
+	struct u34_report_header hdr;
+	u16 crc_calc;
+	u16 crc_report;
+	u8 len;
+	u16 hdr_buf = get_unaligned_le16(&report[0]);
+
+	dev_dbg(ax->dev, "Payload Data %*ph\n", ax->max_report_len, report);
+
+	hdr.report_length = FIELD_GET(AX_U34_LEN_MASK, hdr_buf);
+	hdr.overflow = !!(hdr_buf & AX_U34_OVERFLOW);
+	hdr.report_usage = FIELD_GET(AX_U34_USAGE_MASK, hdr_buf);
+
+	len = hdr.report_length << 1;
+	if (hdr.report_length == 0) {
+		dev_err(ax->dev, "Zero length report discarded.\n");
+		return -EIO;
+	}
+
+	// Length is 16 bit words and remove the size of the CRC16 itself
+	crc_report = (report[len - 1] << 8) | (report[len - 2]);
+	crc_calc = crc16(0, report, (len - 2));
+
+	if (crc_calc != crc_report) {
+		dev_err(ax->dev,
+			"CRC mismatch! Expected: %04X, Calculated CRC: %04X. Report discarded.\n",
+			crc_report, crc_calc);
+		return -EIO;
+	}
+
+	switch (hdr.report_usage) {
+	case AX_2DCTS_REPORT_ID:
+		err = axiom_process_u41_report(ax,
+					       &report[AX_U34_PAYLOAD_BUFFER]);
+		break;
+
+	default:
+		break;
+	}
+
+	return err;
+}
+
+static void axiom_poll(struct input_dev *input_dev)
+{
+	struct axiom *ax = input_get_drvdata(input_dev);
+	int err;
+
+	/* Read touch reports from u34 */
+	err = ax->bus_ops->read(ax->dev, ax->u34_address, ax->max_report_len,
+				ax->read_buf);
+	if (err)
+		return;
+
+	err = axiom_process_report(ax, ax->read_buf);
+	if (err)
+		dev_err(ax->dev, "Failed to process report: %d\n", err);
+}
+
+static irqreturn_t axiom_irq(int irq, void *handle)
+{
+	struct axiom *ax = handle;
+	int err;
+
+	/* Read touch reports from u34 */
+	err = ax->bus_ops->read(ax->dev, ax->u34_address, ax->max_report_len,
+				ax->read_buf);
+	if (err)
+		goto out;
+
+	err = axiom_process_report(ax, ax->read_buf);
+	if (err)
+		dev_err(ax->dev, "Failed to process report: %d\n", err);
+
+out:
+	return IRQ_HANDLED;
+}
+
+struct axiom *axiom_probe(const struct axiom_bus_ops *bus_ops,
+			  struct device *dev, int irq)
+{
+	struct axiom *ax;
+	struct input_dev *input_dev;
+	int err;
+	bool poll_enable = false;
+	u8 poll_period = 0;
+
+	ax = devm_kzalloc(dev, sizeof(*ax), GFP_KERNEL);
+	if (!ax)
+		return ERR_PTR(-ENOMEM);
+
+	input_dev = devm_input_allocate_device(dev);
+	if (!input_dev) {
+		pr_err("ERROR: aXiom-core: Failed to allocate memory for input device!\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	poll_enable = device_property_read_bool(dev, "axiom,poll-enable");
+
+	device_property_read_u8(dev, "axiom,poll-period", &poll_period);
+	if (!poll_period)
+		poll_period = AX_POLLING_PERIOD_MS;
+
+	ax->dev = dev;
+	ax->input = input_dev;
+	ax->bus_ops = bus_ops;
+	ax->irq = irq;
+
+	dev_info(dev, "aXiom Probe\n");
+	if (poll_enable)
+		dev_info(dev, "Polling Period : %u\n", poll_period);
+	else
+		dev_info(dev, "Device IRQ : %u\n", ax->irq);
+
+	axiom_set_capabilities(input_dev);
+
+	err = axiom_init_dev_info(ax);
+	if (err) {
+		dev_err(ax->dev, "Failed to read device info, err: %d\n", err);
+		return ERR_PTR(err);
+	}
+
+	if (poll_enable) {
+		err = input_setup_polling(input_dev, axiom_poll);
+		if (err) {
+			dev_err(ax->dev, "could not set up polling mode, %d\n",
+				err);
+			return ERR_PTR(err);
+		}
+
+		input_set_poll_interval(input_dev, poll_period);
+	} else {
+		err = devm_request_threaded_irq(ax->dev, ax->irq, NULL,
+						axiom_irq,
+						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						"axiom_irq", ax);
+		if (err)
+			return ERR_PTR(err);
+	}
+
+	err = input_register_device(input_dev);
+	if (err) {
+		dev_err(ax->dev, "Failed to register input device: %d\n", err);
+		return ERR_PTR(err);
+	}
+
+	input_set_drvdata(input_dev, ax);
+
+	return ax;
+}
+EXPORT_SYMBOL_GPL(axiom_probe);
+
+MODULE_AUTHOR("TouchNetix <support@touchnetix.com>");
+MODULE_DESCRIPTION("aXiom touchscreen core logic");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("axiom");
+MODULE_VERSION("1.0.0");
diff --git a/drivers/input/touchscreen/axiom_core.h b/drivers/input/touchscreen/axiom_core.h
new file mode 100644
index 000000000000..ca77f9038cb1
--- /dev/null
+++ b/drivers/input/touchscreen/axiom_core.h
@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * TouchNetix aXiom Touchscreen Driver
+ *
+ * Copyright (C) 2020-2026 TouchNetix Ltd.
+ *
+ * Author(s): Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
+ *            Pedro Torruella <pedro.torruella@touchnetix.com>
+ *            Bart Prescott <bartp@baasheep.co.uk>
+ *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
+ *            Andrew Thomas <andrew.thomas@touchnetix.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+
+#ifndef __AXIOM_CORE_H
+#define __AXIOM_CORE_H
+
+#include <linux/input.h>
+
+#define AX_POLLING_PERIOD_MS (10)
+
+#define AXIOM_USE_TOUCHSCREEN_INTERFACE // registers the axiom device as a touch screen instead of as a mouse pointer
+#define U46_ENABLE_RAW_FORCE_DATA // enables the raw data for up to 4 force channels to be sent to the input subsystem
+
+#define AXIOM_PAGE_SIZE (256)
+// u31 has 2 pages for usage table entries. (2 * PAGE_SIZE) / U31_BYTES_PER_USAGE = 85
+#define AXIOM_MAX_READ_SIZE (2 * AXIOM_PAGE_SIZE)
+#define SIZE_U31_DEVICE_INFO (12)
+#define SIZE_U31_USAGE_ENTRY (6)
+#define U31_MAX_USAGES (85U)
+#define U41_MAX_TARGETS (10U)
+#define U41_PROX_LEVEL (-128)
+#define AXIOM_HOLDOFF_DELAY_US (40)
+
+enum ax_comms_op_e { AX_WR_OP = 0, AX_RD_OP = 1 };
+
+enum report_ids_e {
+	AX_2DCTS_REPORT_ID = 0x41,
+};
+
+enum axiom_mode_e {
+	AX_RUNTIME_STATE = 0,
+	AX_BOOTLOADER_STATE = 1,
+};
+
+enum usage_type_e {
+	UNKNOWN = 0,
+	OTHER = 1,
+	REPORT = 2,
+	REGISTER = 3,
+	REGISTER_READ_ONLY_ = 4,
+	CDU = 5,
+	CDU_READ_ONLY_ = 6,
+};
+
+struct axiom_device_info {
+	u16 device_id;
+	u8 mode;
+	u8 runtime_fw_rev_minor;
+	u8 runtime_fw_rev_major;
+	u8 device_build_variant;
+	u8 runtime_fw_status;
+	u8 tcp_revision;
+	u8 bootloader_fw_rev_minor;
+	u8 bootloader_fw_rev_major;
+	u8 jedec_id;
+	u8 num_usages;
+	u8 silicon_revision;
+	u8 runtime_fw_rev_patch;
+};
+
+struct u31_usage_entry {
+	u8 usage_num;
+	u8 start_page;
+	u8 num_pages;
+	u8 max_offset;
+	u8 offset_type;
+	u8 uifrevision;
+	u8 usage_type;
+};
+
+struct axiom_cmd_header {
+	u16 target_address;
+	u16 length : 15;
+	u16 rd_wr : 1;
+};
+
+struct axiom_bus_ops {
+	u16 bustype;
+	int (*write)(struct device *dev, u16 addr, u16 length, void *values);
+	int (*read)(struct device *dev, u16 addr, u16 length, void *values);
+};
+
+enum u41_target_state_e {
+	Target_State_Not_Present = 0,
+	Target_State_Prox = 1,
+	Target_State_Hover = 2,
+	Target_State_Touching = 3,
+};
+
+struct axiom {
+	struct device *dev;
+	int irq;
+	struct input_dev *input;
+	const struct axiom_bus_ops *bus_ops;
+	struct axiom_device_info dev_info;
+	struct u31_usage_entry usage_table[U31_MAX_USAGES];
+	u16 max_report_len;
+	u16 u34_address;
+
+	u8 read_buf[AXIOM_MAX_READ_SIZE];
+};
+
+struct u34_report_header {
+	u8 report_length;
+	u8 overflow;
+	u8 report_usage;
+};
+
+struct axiom *axiom_probe(const struct axiom_bus_ops *bus_ops,
+			  struct device *dev, int irq);
+
+#endif /* __AXIOM_CORE_H */
diff --git a/drivers/input/touchscreen/axiom_i2c.c b/drivers/input/touchscreen/axiom_i2c.c
new file mode 100644
index 000000000000..66071cc0f7b3
--- /dev/null
+++ b/drivers/input/touchscreen/axiom_i2c.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TouchNetix aXiom Touchscreen Driver
+ *
+ * Copyright (C) 2020-2026 TouchNetix Ltd.
+ *
+ * Author(s): Bart Prescott <bartp@baasheep.co.uk>
+ *            Pedro Torruella <pedro.torruella@touchnetix.com>
+ *            Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
+ *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
+ *            Andrew Thomas <andrew.thomas@touchnetix.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+
+// #define DEBUG // Enable debug messages
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include "axiom_core.h"
+
+static int axiom_i2c_read_block_data(struct device *dev, u16 addr, u16 length,
+				     void *values)
+{
+	int error;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct axiom_cmd_header cmd_header = { .target_address = addr,
+					       .length = length,
+					       .rd_wr = AX_RD_OP };
+
+	struct i2c_msg msgs[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.len = sizeof(cmd_header),
+			.buf = (u8 *)&cmd_header,
+		},
+		{
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = length,
+			.buf = values,
+		},
+	};
+
+	error = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (error < 0) {
+		dev_err(dev, "I2C transfer error: %d\n", error);
+		return error;
+	}
+
+	udelay(AXIOM_HOLDOFF_DELAY_US);
+
+	return error != ARRAY_SIZE(msgs) ? -EIO : 0;
+}
+
+static int axiom_i2c_write_block_data(struct device *dev, u16 addr, u16 length,
+				      void *values)
+{
+	int error;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct axiom_cmd_header cmd_header = { .target_address = addr,
+					       .length = length,
+					       .rd_wr = AX_WR_OP };
+
+	struct i2c_msg msgs[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.len = sizeof(cmd_header),
+			.buf = (u8 *)&cmd_header,
+		},
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.len = length,
+			.buf = values,
+		},
+	};
+
+	error = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (error < 0) {
+		dev_err(dev, "I2C transfer error: %d\n", error);
+		return error;
+	}
+
+	udelay(AXIOM_HOLDOFF_DELAY_US);
+
+	return error != ARRAY_SIZE(msgs) ? -EIO : 0;
+}
+
+static const struct axiom_bus_ops axiom_i2c_bus_ops = {
+	.bustype = BUS_I2C,
+	.write = axiom_i2c_write_block_data,
+	.read = axiom_i2c_read_block_data,
+};
+
+static int axiom_i2c_probe(struct i2c_client *client)
+{
+	struct axiom *axiom;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev, "I2C functionality not Supported\n");
+		return -EIO;
+	}
+
+	axiom = axiom_probe(&axiom_i2c_bus_ops, &client->dev, client->irq);
+	if (IS_ERR(axiom))
+		return dev_err_probe(&client->dev, PTR_ERR(axiom),
+				     "failed to register input device\n");
+
+	return 0;
+}
+
+static const struct i2c_device_id axiom_i2c_id_table[] = {
+	{ "axiom-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
+
+static const struct of_device_id axiom_i2c_dt_ids[] = {
+	{
+		.compatible = "tnx,axiom-i2c",
+		.data = "axiom",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, axiom_i2c_dt_ids);
+
+static struct i2c_driver axiom_i2c_driver = {
+	.driver = {
+		.name = "axiom_i2c",
+		.of_match_table = of_match_ptr(axiom_i2c_dt_ids),
+	},
+	.id_table = axiom_i2c_id_table,
+	.probe = axiom_i2c_probe,
+};
+
+module_i2c_driver(axiom_i2c_driver);
+
+MODULE_AUTHOR("TouchNetix <support@touchnetix.com>");
+MODULE_DESCRIPTION("aXiom touchscreen I2C bus driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("axiom");
+MODULE_VERSION("1.0.0");
diff --git a/drivers/input/touchscreen/axiom_spi.c b/drivers/input/touchscreen/axiom_spi.c
new file mode 100644
index 000000000000..a67ad3645689
--- /dev/null
+++ b/drivers/input/touchscreen/axiom_spi.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TouchNetix aXiom Touchscreen Driver
+ *
+ * Copyright (C) 2018-2023 TouchNetix Ltd.
+ *
+ * Author(s): Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
+ *            Bart Prescott <bartp@baasheep.co.uk>
+ *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
+ *            Andrew Thomas <andrew.thomas@touchnetix.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+
+// #define DEBUG // Enable debug messages
+
+#include <linux/of.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/input.h>
+#include "axiom_core.h"
+
+#define SPI_PADDING_LEN 32
+
+static int axiom_spi_transfer(struct device *dev, enum ax_comms_op_e op,
+			      u16 addr, u16 length, void *values)
+{
+	int ret;
+	struct spi_device *spi = to_spi_device(dev);
+	struct spi_transfer xfr_header;
+	struct spi_transfer xfr_padding;
+	struct spi_transfer xfr_payload;
+	struct spi_message msg;
+	struct axiom_cmd_header cmd_header = { .target_address = addr,
+					       .length = length,
+					       .rd_wr = op };
+	u8 pad_buf[SPI_PADDING_LEN] = { 0 };
+
+	memset(&xfr_header, 0, sizeof(xfr_header));
+	memset(&xfr_padding, 0, sizeof(xfr_padding));
+	memset(&xfr_payload, 0, sizeof(xfr_payload));
+
+	/* Setup the SPI transfer operations */
+	xfr_header.tx_buf = &cmd_header;
+	xfr_header.len = sizeof(cmd_header);
+
+	xfr_padding.tx_buf = pad_buf;
+	xfr_padding.len = sizeof(pad_buf);
+
+	switch (op) {
+	case AX_WR_OP:
+		xfr_payload.tx_buf = values;
+		break;
+	case AX_RD_OP:
+		xfr_payload.rx_buf = values;
+		break;
+	default:
+		dev_err(dev, "%s: invalid operation: %d\n", __func__, op);
+		return -EINVAL;
+	}
+	xfr_payload.len = length;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfr_header, &msg);
+	spi_message_add_tail(&xfr_padding, &msg);
+	spi_message_add_tail(&xfr_payload, &msg);
+
+	ret = spi_sync(spi, &msg);
+	if (ret < 0) {
+		dev_err(&spi->dev, "Failed to SPI transfer, error: %d\n", ret);
+		return ret;
+	}
+
+	udelay(AXIOM_HOLDOFF_DELAY_US);
+
+	return 0;
+}
+
+static int axiom_spi_read_block_data(struct device *dev, u16 addr, u16 length,
+				     void *values)
+{
+	return axiom_spi_transfer(dev, AX_RD_OP, addr, length, values);
+}
+
+static int axiom_spi_write_block_data(struct device *dev, u16 addr, u16 length,
+				      void *values)
+{
+	return axiom_spi_transfer(dev, AX_WR_OP, addr, length, values);
+}
+
+static const struct axiom_bus_ops axiom_spi_bus_ops = {
+	.bustype = BUS_SPI,
+	.write = axiom_spi_write_block_data,
+	.read = axiom_spi_read_block_data,
+};
+
+static int axiom_spi_probe(struct spi_device *spi)
+{
+	struct axiom *axiom;
+	int error;
+
+	/* Set up SPI */
+	spi->bits_per_word = 8;
+	spi->mode = SPI_MODE_0;
+	spi->max_speed_hz = 4000000;
+
+	if (spi->irq == 0)
+		dev_err(&spi->dev, "No IRQ specified!\n");
+
+	error = spi_setup(spi);
+	if (error < 0) {
+		dev_err(&spi->dev, "%s: SPI setup error %d\n", __func__, error);
+		return error;
+	}
+	axiom = axiom_probe(&axiom_spi_bus_ops, &spi->dev, spi->irq);
+	if (IS_ERR(axiom))
+		return dev_err_probe(&spi->dev, PTR_ERR(axiom),
+				     "failed to register input device\n");
+
+	return 0;
+}
+
+static const struct spi_device_id axiom_spi_id_table[] = {
+	{ "axiom-spi" },
+	{},
+};
+MODULE_DEVICE_TABLE(spi, axiom_spi_id_table);
+
+static const struct of_device_id axiom_spi_dt_ids[] = {
+	{
+		.compatible = "tnx,axiom-spi",
+		.data = "axiom",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, axiom_spi_dt_ids);
+
+static struct spi_driver axiom_spi_driver = {
+	.id_table = axiom_spi_id_table,
+	.driver = {
+		.name = "axiom_spi",
+		.of_match_table = of_match_ptr(axiom_spi_dt_ids),
+	},
+	.probe = axiom_spi_probe,
+};
+
+module_spi_driver(axiom_spi_driver);
+
+MODULE_AUTHOR("TouchNetix <support@touchnetix.com>");
+MODULE_DESCRIPTION("aXiom touchscreen SPI bus driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("axiom");
+MODULE_VERSION("1.0.0");
-- 
2.43.0

Re: [PATCH 1/1] Adding support for aXiom touchscreen controller

[kernel test robot]

Hi AThomas63,

kernel test robot noticed the following build errors:

[auto build test ERROR on dtor-input/next]
[also build test ERROR on dtor-input/for-linus hid/for-next linus/master v6.19-rc6 next-20260122]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/AThomas63/Adding-support-for-aXiom-touchscreen-controller/20260122-212452
base:   https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git next
patch link:    https://lore.kernel.org/r/20260122124819.273188-2-andrew.thomas%40touchnetix.com
patch subject: [PATCH 1/1] Adding support for aXiom touchscreen controller
config: sh-randconfig-r072-20260123 (https://download.01.org/0day-ci/archive/20260123/202601230252.ZlyhNYe2-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 14.3.0
smatch version: v0.5.0-8994-gd50c5a4c
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260123/202601230252.ZlyhNYe2-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601230252.ZlyhNYe2-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/input/touchscreen/axiom_core.c: In function 'axiom_unpack_device_info':
>> drivers/input/touchscreen/axiom_core.c:110:27: error: implicit declaration of function 'FIELD_GET' [-Wimplicit-function-declaration]
     110 |         info->device_id = FIELD_GET(AX_DEV_ID_MASK, w);
         |                           ^~~~~~~~~


vim +/FIELD_GET +110 drivers/input/touchscreen/axiom_core.c

   103	
   104	static void axiom_unpack_device_info(const u8 *buf,
   105					     struct axiom_device_info *info)
   106	{
   107		u16 w;
   108	
   109		w = get_unaligned_le16(buf);
 > 110		info->device_id = FIELD_GET(AX_DEV_ID_MASK, w);
   111		info->mode = !!(w & AX_MODE);
   112	
   113		w = get_unaligned_le16(buf + 2);
   114		info->runtime_fw_rev_minor = FIELD_GET(AX_FW_REV_MINOR_MASK, w);
   115		info->runtime_fw_rev_major = FIELD_GET(AX_FW_REV_MAJOR_MASK, w);
   116	
   117		w = get_unaligned_le16(buf + 4);
   118		info->device_build_variant = FIELD_GET(AX_VARIANT_MASK, w);
   119		info->runtime_fw_status = !!(w & AX_FW_STATUS);
   120		info->tcp_revision = FIELD_GET(AX_TCP_REV_MASK, w);
   121	
   122		w = get_unaligned_le16(buf + 6);
   123		info->bootloader_fw_rev_minor = FIELD_GET(AX_BOOT_REV_MINOR_MASK, w);
   124		info->bootloader_fw_rev_major = FIELD_GET(AX_BOOT_REV_MAJOR_MASK, w);
   125	
   126		info->jedec_id = get_unaligned_le16(buf + 8);
   127	
   128		w = get_unaligned_le16(buf + 10);
   129		info->num_usages = FIELD_GET(AX_NUM_USAGES_MASK, w);
   130		info->silicon_revision = FIELD_GET(AX_SILICON_REV_MASK, w);
   131		info->runtime_fw_rev_patch = FIELD_GET(AX_RUNTIME_FW_PATCH_MASK, w);
   132	}
   133	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 1/1] Adding support for aXiom touchscreen controller

[Marco Felsch]

The git-subject seems wrong, this should be:

"Input: Add support for ...."

also you miss a proper commit description.

On 26-01-22, AThomas63 wrote:
> Signed-off-by: AThomas63 <andrew.thomas@touchnetix.com>
> ---
>  drivers/input/touchscreen/Kconfig      |  30 ++
>  drivers/input/touchscreen/Makefile     |   3 +
>  drivers/input/touchscreen/axiom_core.c | 482 +++++++++++++++++++++++++
>  drivers/input/touchscreen/axiom_core.h | 128 +++++++
>  drivers/input/touchscreen/axiom_i2c.c  | 152 ++++++++
>  drivers/input/touchscreen/axiom_spi.c  | 159 ++++++++
>  6 files changed, 954 insertions(+)
>  create mode 100644 drivers/input/touchscreen/axiom_core.c
>  create mode 100644 drivers/input/touchscreen/axiom_core.h
>  create mode 100644 drivers/input/touchscreen/axiom_i2c.c
>  create mode 100644 drivers/input/touchscreen/axiom_spi.c
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 7d5b72ee07fa..f2b4fb317bdd 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -162,6 +162,36 @@ config TOUCHSCREEN_AUO_PIXCIR
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called auo-pixcir-ts.
>  
> +config TOUCHSCREEN_AXIOM_CORE
> +	tristate "TouchNetix Axiom touchscreen"

Nack, the spi or i2c should select the core.

> +	help
> +	  Say Y here if you have an Axiom touchscreen connected
> +	  to your system. You will also need to select appropriate
> +	  bus connection below.
> +
> +	  If unsure, say N.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called axiom_core.
> +
> +config TOUCHSCREEN_AXIOM_I2C
> +	tristate "support I2C bus connection"
> +	depends on TOUCHSCREEN_AXIOM_CORE && I2C
> +	help
> +	  Say Y here if the touchscreen is connected via I2C bus.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called axiom_spi.
> +
> +config TOUCHSCREEN_AXIOM_SPI
> +	tristate "support SPI bus connection"
> +	depends on TOUCHSCREEN_AXIOM_CORE && SPI
> +	help
> +	  Say Y here if the touchscreen is connected via SPI bus.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called axiom_spi.
> +
>  config TOUCHSCREEN_BU21013
>  	tristate "BU21013 based touch panel controllers"
>  	depends on I2C
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index ab9abd151078..9b7d572c4589 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -19,6 +19,9 @@ obj-$(CONFIG_TOUCHSCREEN_APPLE_Z2)	+= apple_z2.o
>  obj-$(CONFIG_TOUCHSCREEN_AR1021_I2C)	+= ar1021_i2c.o
>  obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT)	+= atmel_mxt_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_AUO_PIXCIR)	+= auo-pixcir-ts.o
> +obj-$(CONFIG_TOUCHSCREEN_AXIOM_CORE)	+= axiom_core.o
> +obj-$(CONFIG_TOUCHSCREEN_AXIOM_I2C)	+= axiom_i2c.o
> +obj-$(CONFIG_TOUCHSCREEN_AXIOM_SPI)	+= axiom_spi.o
>  obj-$(CONFIG_TOUCHSCREEN_BU21013)	+= bu21013_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_BU21029)	+= bu21029_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318)	+= chipone_icn8318.o
> diff --git a/drivers/input/touchscreen/axiom_core.c b/drivers/input/touchscreen/axiom_core.c
> new file mode 100644
> index 000000000000..7983effe40f7
> --- /dev/null
> +++ b/drivers/input/touchscreen/axiom_core.c
> @@ -0,0 +1,482 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * TouchNetix aXiom Touchscreen Driver
> + *
> + * Copyright (C) 2020-2026 TouchNetix Ltd.
> + *
> + * Author(s): Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
> + *            Pedro Torruella <pedro.torruella@touchnetix.com>
> + *            Bart Prescott <bartp@baasheep.co.uk>
> + *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
> + *            Andrew Thomas <andrew.thomas@touchnetix.com>
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + *
> + */
> +
> +// #define DEBUG // Enable debug messages

remove this

> +
> +#include <linux/device.h>
> +#include <linux/input/mt.h>
> +#include <linux/crc16.h>
> +#include <linux/property.h>
> +#include <linux/interrupt.h>
> +#include <linux/unaligned.h>
> +#include "axiom_core.h"
> +
> +/* u31 device info masks */
> +#define AX_DEV_ID_MASK GENMASK(14, 0)
> +#define AX_MODE BIT(15)
> +#define AX_FW_REV_MINOR_MASK GENMASK(7, 0)
> +#define AX_FW_REV_MAJOR_MASK GENMASK(15, 8)
> +#define AX_VARIANT_MASK GENMASK(5, 0)
> +#define AX_FW_STATUS BIT(7)
> +#define AX_TCP_REV_MASK GENMASK(15, 8)
> +#define AX_BOOT_REV_MINOR_MASK GENMASK(7, 0)
> +#define AX_BOOT_REV_MAJOR_MASK GENMASK(15, 8)
> +#define AX_NUM_USAGES_MASK GENMASK(7, 0)
> +#define AX_SILICON_REV_MASK GENMASK(11, 8)
> +#define AX_RUNTIME_FW_PATCH_MASK GENMASK(15, 12)
> +
> +/* u31 usage table entry masks */
> +#define AX_U31_USAGE_NUM_MASK GENMASK(7, 0)
> +#define AX_U31_START_PAGE_MASK GENMASK(15, 8)
> +#define AX_U31_NUM_PAGES_MASK GENMASK(7, 0)
> +#define AX_U31_MAX_OFFSET_MASK GENMASK(14, 8)
> +#define AX_U31_OFFSET_TYPE_BIT BIT(15)
> +#define AX_U31_UIF_REV_MASK GENMASK(7, 0)
> +#define AX_U31_USAGE_TYPE_MASK GENMASK(15, 8)
> +
> +/* u34 report masks */
> +#define AX_U34_LEN_MASK GENMASK(6, 0)
> +#define AX_U34_OVERFLOW BIT(7)
> +#define AX_U34_USAGE_MASK GENMASK(15, 8)
> +#define AX_U34_PAYLOAD_BUFFER 2
> +
> +/* u41 report masks */
> +#define AX_U41_PRESENT_MASK GENMASK(9, 0)
> +#define U41_X_Y_OFFSET (2)
> +#define U41_COORD_SIZE (4)
> +#define U41_Z_OFFSET (42)

Align your defines.

> +
> +static const char *const fw_variants[] = { "3D", "2D", "FORCE",
> +					   "0D", "XL", "TOUCHPAD" };

Check your code against the kernel coding style, this applies to many
code parts, I won't list them all.

> +
> +static int axiom_set_capabilities(struct input_dev *input_dev)
> +{
> +	input_dev->name = "TouchNetix aXiom Touchscreen";
> +	input_dev->phys = "input/axiom_ts";
> +
> +	// Single Touch

Coding style.

> +	input_set_abs_params(input_dev, ABS_X, 0, 65535, 0, 0);
> +	input_set_abs_params(input_dev, ABS_Y, 0, 65535, 0, 0);
> +
> +	// Multi Touch
> +	// Min, Max, Fuzz (expected noise in px, try 4?) and Flat
> +	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
> +	// Min, Max, Fuzz (expected noise in px, try 4?) and Flat
> +	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
> +	input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
> +	input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
> +	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);

Max values are coming from the firmware.

> +
> +	input_mt_init_slots(input_dev, U41_MAX_TARGETS, INPUT_MT_DIRECT);

num-targets can be configured via firmware config IIRC, so nack.

> +
> +	return 0;
> +}
> +
> +static struct u31_usage_entry *usage_find_entry(struct axiom *ax, u16 usage)
> +{
> +	u16 i;
> +
> +	for (i = 0; i < ax->dev_info.num_usages; i++) {
> +		if (ax->usage_table[i].usage_num == usage)
> +			return &ax->usage_table[i];
> +	}
> +
> +	pr_err("aXiom-core: Usage u%02x not found in usage table\n", usage);
> +	return ERR_PTR(-EINVAL);
> +}
> +
> +static void axiom_unpack_device_info(const u8 *buf,
> +				     struct axiom_device_info *info)
> +{
> +	u16 w;
> +
> +	w = get_unaligned_le16(buf);
> +	info->device_id = FIELD_GET(AX_DEV_ID_MASK, w);
> +	info->mode = !!(w & AX_MODE);
> +
> +	w = get_unaligned_le16(buf + 2);
> +	info->runtime_fw_rev_minor = FIELD_GET(AX_FW_REV_MINOR_MASK, w);
> +	info->runtime_fw_rev_major = FIELD_GET(AX_FW_REV_MAJOR_MASK, w);
> +
> +	w = get_unaligned_le16(buf + 4);
> +	info->device_build_variant = FIELD_GET(AX_VARIANT_MASK, w);
> +	info->runtime_fw_status = !!(w & AX_FW_STATUS);
> +	info->tcp_revision = FIELD_GET(AX_TCP_REV_MASK, w);
> +
> +	w = get_unaligned_le16(buf + 6);
> +	info->bootloader_fw_rev_minor = FIELD_GET(AX_BOOT_REV_MINOR_MASK, w);
> +	info->bootloader_fw_rev_major = FIELD_GET(AX_BOOT_REV_MAJOR_MASK, w);
> +
> +	info->jedec_id = get_unaligned_le16(buf + 8);
> +
> +	w = get_unaligned_le16(buf + 10);
> +	info->num_usages = FIELD_GET(AX_NUM_USAGES_MASK, w);
> +	info->silicon_revision = FIELD_GET(AX_SILICON_REV_MASK, w);
> +	info->runtime_fw_rev_patch = FIELD_GET(AX_RUNTIME_FW_PATCH_MASK, w);
> +}
> +
> +static void axiom_unpack_usage_table(u8 *buf, struct axiom *ax)
> +{
> +	u8 *ptr;
> +	struct u31_usage_entry *entry;
> +	int i;
> +	u16 w;
> +	u16 report_len;
> +
> +	for (i = 0; i < ax->dev_info.num_usages && i < U31_MAX_USAGES; i++) {
> +		entry = &ax->usage_table[i];
> +		/* Calculate offset for this specific entry */
> +		ptr = buf + (i * SIZE_U31_USAGE_ENTRY);
> +
> +		w = get_unaligned_le16(ptr);
> +		entry->usage_num = FIELD_GET(AX_U31_USAGE_NUM_MASK, w);
> +		entry->start_page = FIELD_GET(AX_U31_START_PAGE_MASK, w);
> +
> +		w = get_unaligned_le16(ptr + 2);
> +		entry->num_pages = FIELD_GET(AX_U31_NUM_PAGES_MASK, w);
> +		entry->max_offset = FIELD_GET(AX_U31_MAX_OFFSET_MASK, w);
> +		entry->offset_type = !!(w & AX_U31_OFFSET_TYPE_BIT);
> +
> +		w = get_unaligned_le16(ptr + 4);
> +		entry->uifrevision = FIELD_GET(AX_U31_UIF_REV_MASK, w);
> +		entry->usage_type = FIELD_GET(AX_U31_USAGE_TYPE_MASK, w);
> +
> +		// Convert words to bytes
> +		report_len = (entry->max_offset + 1) * 2;
> +		if ((entry->usage_type == REPORT) &&
> +		    (report_len > ax->max_report_len)) {
> +			ax->max_report_len = report_len;
> +		}
> +	}
> +}
> +
> +static int axiom_init_dev_info(struct axiom *ax)
> +{
> +	int i;
> +	struct u31_usage_entry *u;
> +	int err;
> +	const char *variant_str;
> +
> +	/* Read page 0 of u31 */
> +	err = ax->bus_ops->read(ax->dev, 0x0, SIZE_U31_DEVICE_INFO,
> +				ax->read_buf);

No need for custom accessors, use regmap API.

> +	if (err)
> +		return -EIO;
> +
> +	axiom_unpack_device_info(ax->read_buf, &ax->dev_info);
> +
> +	if (ax->dev_info.device_build_variant < ARRAY_SIZE(fw_variants)) {
> +		variant_str = fw_variants[ax->dev_info.device_build_variant];
> +	} else {
> +		variant_str = "UNKNOWN";
> +	}
> +	char silicon_rev = (char)(0x41 + ax->dev_info.silicon_revision);
> +
> +	dev_info(ax->dev, "Firmware Info:\n");
> +	dev_info(ax->dev, "  BL Mode     : %u\n", ax->dev_info.mode);
> +	dev_info(ax->dev, "  Device ID   : %04x\n", ax->dev_info.device_id);
> +	dev_info(ax->dev, "  FW Revision : %u.%u.%u-%s %s\n",
> +		 ax->dev_info.runtime_fw_rev_major,
> +		 ax->dev_info.runtime_fw_rev_minor,
> +		 ax->dev_info.runtime_fw_rev_patch,
> +		 (ax->dev_info.runtime_fw_status == 0) ? "eng" : "prod",
> +		 variant_str);
> +	dev_info(ax->dev, "  BL Revision : %02x.%02x\n",
> +		 ax->dev_info.bootloader_fw_rev_major,
> +		 ax->dev_info.bootloader_fw_rev_minor);
> +	dev_info(ax->dev, "  Silicon     : 0x%04X (Rev %c)\n",
> +		 ax->dev_info.jedec_id, silicon_rev);
> +	dev_info(ax->dev, "  Num Usages  : %u\n", ax->dev_info.num_usages);

Why always dev_info()?

> +
> +	if (ax->dev_info.num_usages > U31_MAX_USAGES) {
> +		dev_err(ax->dev,
> +			"Num usages (%u) exceeds maximum supported (%u)\n",
> +			ax->dev_info.num_usages, U31_MAX_USAGES);
> +		return -EINVAL;
> +	}
> +
> +	/* Read the second page of u31 to get the usage table */
> +	err = ax->bus_ops->read(ax->dev, 0x100,
> +				sizeof(ax->usage_table[0]) *
> +					ax->dev_info.num_usages,
> +				ax->read_buf);

You don't check if the device is bootloader-mode so this may fail
depending on the device state.

> +	if (err)
> +		return -EIO;
> +
> +	axiom_unpack_usage_table(ax->read_buf, ax);
> +
> +	dev_info(ax->dev, "Usage Table:\n");
> +	for (i = 0; i < ax->dev_info.num_usages; i++) {
> +		u = &ax->usage_table[i];
> +
> +		dev_info(
> +			ax->dev,
> +			"  Usage: u%02x  Rev: %3u  Page: 0x%02x00  Num Pages: %3u\n",
> +			u->usage_num, u->uifrevision, u->start_page,
> +			u->num_pages);
> +	}
> +	dev_info(ax->dev, "Max Report Length: %u\n", ax->max_report_len);
> +
> +	if (ax->max_report_len > AXIOM_MAX_READ_SIZE) {
> +		dev_err(ax->dev,
> +			"aXiom maximum report length (%u) greater than allocated buffer size (%u).",
> +			ax->max_report_len, AXIOM_MAX_READ_SIZE);
> +		return -EINVAL;
> +	}
> +
> +	/* Set u34 address to allow direct access to report reading address */
> +	u = usage_find_entry(ax, 0x34);
> +	if (IS_ERR(u))
> +		return PTR_ERR(u);
> +	ax->u34_address = u->start_page << 8;
> +
> +	return 0;
> +}
> +
> +static int axiom_process_u41_report(struct axiom *ax, u8 *report)
> +{
> +	int i;
> +	u16 target_present;
> +	bool active;
> +	u8 offset;
> +	enum u41_target_state_e state;
> +	u16 x;
> +	u16 y;
> +	s8 z;
> +
> +	target_present =
> +		FIELD_GET(AX_U41_PRESENT_MASK, get_unaligned_le16(&report[0]));
> +
> +	for (i = 0; i < U41_MAX_TARGETS; i++) {
> +		active = !!((target_present >> i) & 1);
> +
> +		offset = U41_X_Y_OFFSET + (i * U41_COORD_SIZE);
> +		x = get_unaligned_le16(&report[offset]);
> +		y = get_unaligned_le16(&report[offset + 2]);
> +		z = report[U41_Z_OFFSET + i];
> +
> +		if (!active)
> +			state = Target_State_Not_Present;
> +		else if (z >= 0)
> +			state = Target_State_Touching;
> +		else if ((z > U41_PROX_LEVEL) && (z < 0))
> +			state = Target_State_Hover;
> +		else if (z == U41_PROX_LEVEL)
> +			state = Target_State_Prox;
> +		else
> +			state = Target_State_Not_Present;
> +
> +		dev_dbg(ax->dev, "Target %d: x=%u y=%u z=%d present=%d\n", i, x,
> +			y, z, active);
> +
> +		switch (state) {
> +		case Target_State_Not_Present:
> +		case Target_State_Prox:
> +
> +			input_mt_slot(ax->input, i);
> +			input_mt_report_slot_inactive(ax->input);
> +			break;
> +
> +		case Target_State_Hover:
> +		case Target_State_Touching:
> +
> +			input_mt_slot(ax->input, i);
> +			input_report_abs(ax->input, ABS_MT_TRACKING_ID, i);
> +			input_report_abs(ax->input, ABS_MT_POSITION_X, x);
> +			input_report_abs(ax->input, ABS_MT_POSITION_Y, y);
> +
> +			if (state == Target_State_Touching) {
> +				input_report_abs(ax->input, ABS_MT_DISTANCE, 0);
> +				input_report_abs(ax->input, ABS_MT_PRESSURE, z);
> +			} else { /* Hover */
> +				input_report_abs(ax->input, ABS_MT_DISTANCE, -z);
> +				input_report_abs(ax->input, ABS_MT_PRESSURE, 0);
> +			}
> +			break;
> +
> +		default:
> +			break;
> +		}
> +	}
> +
> +	input_mt_sync_frame(ax->input);
> +	input_sync(ax->input);
> +
> +	return 0;
> +}
> +
> +static int axiom_process_report(struct axiom *ax, u8 *report)
> +{
> +	int err;
> +	struct u34_report_header hdr;
> +	u16 crc_calc;
> +	u16 crc_report;
> +	u8 len;
> +	u16 hdr_buf = get_unaligned_le16(&report[0]);
> +
> +	dev_dbg(ax->dev, "Payload Data %*ph\n", ax->max_report_len, report);
> +
> +	hdr.report_length = FIELD_GET(AX_U34_LEN_MASK, hdr_buf);
> +	hdr.overflow = !!(hdr_buf & AX_U34_OVERFLOW);
> +	hdr.report_usage = FIELD_GET(AX_U34_USAGE_MASK, hdr_buf);
> +
> +	len = hdr.report_length << 1;
> +	if (hdr.report_length == 0) {
> +		dev_err(ax->dev, "Zero length report discarded.\n");
> +		return -EIO;
> +	}
> +
> +	// Length is 16 bit words and remove the size of the CRC16 itself
> +	crc_report = (report[len - 1] << 8) | (report[len - 2]);
> +	crc_calc = crc16(0, report, (len - 2));
> +
> +	if (crc_calc != crc_report) {
> +		dev_err(ax->dev,
> +			"CRC mismatch! Expected: %04X, Calculated CRC: %04X. Report discarded.\n",
> +			crc_report, crc_calc);
> +		return -EIO;
> +	}
> +
> +	switch (hdr.report_usage) {
> +	case AX_2DCTS_REPORT_ID:
> +		err = axiom_process_u41_report(ax,
> +					       &report[AX_U34_PAYLOAD_BUFFER]);

May I ask why you guys write in your programming manual, that the host
needs to check the usage-revision and you completely ignore this?

> +		break;
> +
> +	default:
> +		break;
> +	}
> +
> +	return err;
> +}
> +
> +static void axiom_poll(struct input_dev *input_dev)
> +{
> +	struct axiom *ax = input_get_drvdata(input_dev);
> +	int err;
> +
> +	/* Read touch reports from u34 */
> +	err = ax->bus_ops->read(ax->dev, ax->u34_address, ax->max_report_len,
> +				ax->read_buf);
> +	if (err)
> +		return;
> +
> +	err = axiom_process_report(ax, ax->read_buf);
> +	if (err)
> +		dev_err(ax->dev, "Failed to process report: %d\n", err);
> +}
> +
> +static irqreturn_t axiom_irq(int irq, void *handle)
> +{
> +	struct axiom *ax = handle;
> +	int err;
> +
> +	/* Read touch reports from u34 */
> +	err = ax->bus_ops->read(ax->dev, ax->u34_address, ax->max_report_len,
> +				ax->read_buf);
> +	if (err)
> +		goto out;
> +
> +	err = axiom_process_report(ax, ax->read_buf);
> +	if (err)
> +		dev_err(ax->dev, "Failed to process report: %d\n", err);
> +
> +out:
> +	return IRQ_HANDLED;
> +}
> +
> +struct axiom *axiom_probe(const struct axiom_bus_ops *bus_ops,
> +			  struct device *dev, int irq)
> +{
> +	struct axiom *ax;
> +	struct input_dev *input_dev;
> +	int err;
> +	bool poll_enable = false;
> +	u8 poll_period = 0;

Reverse christmas tree, coding style.

> +
> +	ax = devm_kzalloc(dev, sizeof(*ax), GFP_KERNEL);
> +	if (!ax)
> +		return ERR_PTR(-ENOMEM);
> +
> +	input_dev = devm_input_allocate_device(dev);
> +	if (!input_dev) {
> +		pr_err("ERROR: aXiom-core: Failed to allocate memory for input device!\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	poll_enable = device_property_read_bool(dev, "axiom,poll-enable");

There is common dt-property for poll.

> +
> +	device_property_read_u8(dev, "axiom,poll-period", &poll_period);
> +	if (!poll_period)
> +		poll_period = AX_POLLING_PERIOD_MS;
> +
> +	ax->dev = dev;
> +	ax->input = input_dev;
> +	ax->bus_ops = bus_ops;
> +	ax->irq = irq;

You allocate absolute no ext. resources like regulators or reset-gpios.

> +
> +	dev_info(dev, "aXiom Probe\n");
> +	if (poll_enable)
> +		dev_info(dev, "Polling Period : %u\n", poll_period);
> +	else
> +		dev_info(dev, "Device IRQ : %u\n", ax->irq);

Useless dev_info()'s

> +
> +	axiom_set_capabilities(input_dev);

Capabilities should be set after you know which firmware you're running
on, e.g. if the firmware supports 3D touchevents.

I will stop now. As said, I'm very surprised why you guys went this way
instead of just adding the SPI support to my patchset?

Your driver is missing the basics like checking the usage-revision which
is clearly written within your programming-guide. Also this driver is
missing the fw-update and cfg-update mechanism as well as basic resource
handling like ext. power-supplies.

I'd really appreciate if you guys could provide feedback to the driver
I've send so we can fix some "Downstream" comments :)

Regards,
  Marco

> +
> +	err = axiom_init_dev_info(ax);
> +	if (err) {
> +		dev_err(ax->dev, "Failed to read device info, err: %d\n", err);
> +		return ERR_PTR(err);
> +	}
> +
> +	if (poll_enable) {
> +		err = input_setup_polling(input_dev, axiom_poll);
> +		if (err) {
> +			dev_err(ax->dev, "could not set up polling mode, %d\n",
> +				err);
> +			return ERR_PTR(err);
> +		}
> +
> +		input_set_poll_interval(input_dev, poll_period);
> +	} else {
> +		err = devm_request_threaded_irq(ax->dev, ax->irq, NULL,
> +						axiom_irq,
> +						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +						"axiom_irq", ax);
> +		if (err)
> +			return ERR_PTR(err);
> +	}
> +
> +	err = input_register_device(input_dev);
> +	if (err) {
> +		dev_err(ax->dev, "Failed to register input device: %d\n", err);
> +		return ERR_PTR(err);
> +	}
> +
> +	input_set_drvdata(input_dev, ax);
> +
> +	return ax;
> +}
> +EXPORT_SYMBOL_GPL(axiom_probe);
> +
> +MODULE_AUTHOR("TouchNetix <support@touchnetix.com>");
> +MODULE_DESCRIPTION("aXiom touchscreen core logic");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("axiom");
> +MODULE_VERSION("1.0.0");
> diff --git a/drivers/input/touchscreen/axiom_core.h b/drivers/input/touchscreen/axiom_core.h
> new file mode 100644
> index 000000000000..ca77f9038cb1
> --- /dev/null
> +++ b/drivers/input/touchscreen/axiom_core.h
> @@ -0,0 +1,128 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * TouchNetix aXiom Touchscreen Driver
> + *
> + * Copyright (C) 2020-2026 TouchNetix Ltd.
> + *
> + * Author(s): Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
> + *            Pedro Torruella <pedro.torruella@touchnetix.com>
> + *            Bart Prescott <bartp@baasheep.co.uk>
> + *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
> + *            Andrew Thomas <andrew.thomas@touchnetix.com>
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + *
> + */
> +
> +#ifndef __AXIOM_CORE_H
> +#define __AXIOM_CORE_H
> +
> +#include <linux/input.h>
> +
> +#define AX_POLLING_PERIOD_MS (10)
> +
> +#define AXIOM_USE_TOUCHSCREEN_INTERFACE // registers the axiom device as a touch screen instead of as a mouse pointer
> +#define U46_ENABLE_RAW_FORCE_DATA // enables the raw data for up to 4 force channels to be sent to the input subsystem
> +
> +#define AXIOM_PAGE_SIZE (256)
> +// u31 has 2 pages for usage table entries. (2 * PAGE_SIZE) / U31_BYTES_PER_USAGE = 85
> +#define AXIOM_MAX_READ_SIZE (2 * AXIOM_PAGE_SIZE)
> +#define SIZE_U31_DEVICE_INFO (12)
> +#define SIZE_U31_USAGE_ENTRY (6)
> +#define U31_MAX_USAGES (85U)
> +#define U41_MAX_TARGETS (10U)
> +#define U41_PROX_LEVEL (-128)
> +#define AXIOM_HOLDOFF_DELAY_US (40)
> +
> +enum ax_comms_op_e { AX_WR_OP = 0, AX_RD_OP = 1 };
> +
> +enum report_ids_e {
> +	AX_2DCTS_REPORT_ID = 0x41,
> +};
> +
> +enum axiom_mode_e {
> +	AX_RUNTIME_STATE = 0,
> +	AX_BOOTLOADER_STATE = 1,
> +};
> +
> +enum usage_type_e {
> +	UNKNOWN = 0,
> +	OTHER = 1,
> +	REPORT = 2,
> +	REGISTER = 3,
> +	REGISTER_READ_ONLY_ = 4,
> +	CDU = 5,
> +	CDU_READ_ONLY_ = 6,
> +};
> +
> +struct axiom_device_info {
> +	u16 device_id;
> +	u8 mode;
> +	u8 runtime_fw_rev_minor;
> +	u8 runtime_fw_rev_major;
> +	u8 device_build_variant;
> +	u8 runtime_fw_status;
> +	u8 tcp_revision;
> +	u8 bootloader_fw_rev_minor;
> +	u8 bootloader_fw_rev_major;
> +	u8 jedec_id;
> +	u8 num_usages;
> +	u8 silicon_revision;
> +	u8 runtime_fw_rev_patch;
> +};
> +
> +struct u31_usage_entry {
> +	u8 usage_num;
> +	u8 start_page;
> +	u8 num_pages;
> +	u8 max_offset;
> +	u8 offset_type;
> +	u8 uifrevision;
> +	u8 usage_type;
> +};
> +
> +struct axiom_cmd_header {
> +	u16 target_address;
> +	u16 length : 15;
> +	u16 rd_wr : 1;
> +};
> +
> +struct axiom_bus_ops {
> +	u16 bustype;
> +	int (*write)(struct device *dev, u16 addr, u16 length, void *values);
> +	int (*read)(struct device *dev, u16 addr, u16 length, void *values);
> +};
> +
> +enum u41_target_state_e {
> +	Target_State_Not_Present = 0,
> +	Target_State_Prox = 1,
> +	Target_State_Hover = 2,
> +	Target_State_Touching = 3,
> +};
> +
> +struct axiom {
> +	struct device *dev;
> +	int irq;
> +	struct input_dev *input;
> +	const struct axiom_bus_ops *bus_ops;
> +	struct axiom_device_info dev_info;
> +	struct u31_usage_entry usage_table[U31_MAX_USAGES];
> +	u16 max_report_len;
> +	u16 u34_address;
> +
> +	u8 read_buf[AXIOM_MAX_READ_SIZE];
> +};
> +
> +struct u34_report_header {
> +	u8 report_length;
> +	u8 overflow;
> +	u8 report_usage;
> +};
> +
> +struct axiom *axiom_probe(const struct axiom_bus_ops *bus_ops,
> +			  struct device *dev, int irq);
> +
> +#endif /* __AXIOM_CORE_H */
> diff --git a/drivers/input/touchscreen/axiom_i2c.c b/drivers/input/touchscreen/axiom_i2c.c
> new file mode 100644
> index 000000000000..66071cc0f7b3
> --- /dev/null
> +++ b/drivers/input/touchscreen/axiom_i2c.c
> @@ -0,0 +1,152 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * TouchNetix aXiom Touchscreen Driver
> + *
> + * Copyright (C) 2020-2026 TouchNetix Ltd.
> + *
> + * Author(s): Bart Prescott <bartp@baasheep.co.uk>
> + *            Pedro Torruella <pedro.torruella@touchnetix.com>
> + *            Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
> + *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
> + *            Andrew Thomas <andrew.thomas@touchnetix.com>
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + *
> + */
> +
> +// #define DEBUG // Enable debug messages
> +
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/delay.h>
> +#include <linux/module.h>
> +#include <linux/input.h>
> +#include "axiom_core.h"
> +
> +static int axiom_i2c_read_block_data(struct device *dev, u16 addr, u16 length,
> +				     void *values)
> +{
> +	int error;
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct axiom_cmd_header cmd_header = { .target_address = addr,
> +					       .length = length,
> +					       .rd_wr = AX_RD_OP };
> +
> +	struct i2c_msg msgs[] = {
> +		{
> +			.addr = client->addr,
> +			.flags = 0,
> +			.len = sizeof(cmd_header),
> +			.buf = (u8 *)&cmd_header,
> +		},
> +		{
> +			.addr = client->addr,
> +			.flags = I2C_M_RD,
> +			.len = length,
> +			.buf = values,
> +		},
> +	};
> +
> +	error = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> +	if (error < 0) {
> +		dev_err(dev, "I2C transfer error: %d\n", error);
> +		return error;
> +	}
> +
> +	udelay(AXIOM_HOLDOFF_DELAY_US);
> +
> +	return error != ARRAY_SIZE(msgs) ? -EIO : 0;
> +}
> +
> +static int axiom_i2c_write_block_data(struct device *dev, u16 addr, u16 length,
> +				      void *values)
> +{
> +	int error;
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct axiom_cmd_header cmd_header = { .target_address = addr,
> +					       .length = length,
> +					       .rd_wr = AX_WR_OP };
> +
> +	struct i2c_msg msgs[] = {
> +		{
> +			.addr = client->addr,
> +			.flags = 0,
> +			.len = sizeof(cmd_header),
> +			.buf = (u8 *)&cmd_header,
> +		},
> +		{
> +			.addr = client->addr,
> +			.flags = 0,
> +			.len = length,
> +			.buf = values,
> +		},
> +	};
> +
> +	error = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> +	if (error < 0) {
> +		dev_err(dev, "I2C transfer error: %d\n", error);
> +		return error;
> +	}
> +
> +	udelay(AXIOM_HOLDOFF_DELAY_US);
> +
> +	return error != ARRAY_SIZE(msgs) ? -EIO : 0;
> +}
> +
> +static const struct axiom_bus_ops axiom_i2c_bus_ops = {
> +	.bustype = BUS_I2C,
> +	.write = axiom_i2c_write_block_data,
> +	.read = axiom_i2c_read_block_data,
> +};
> +
> +static int axiom_i2c_probe(struct i2c_client *client)
> +{
> +	struct axiom *axiom;
> +
> +	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
> +		dev_err(&client->dev, "I2C functionality not Supported\n");
> +		return -EIO;
> +	}
> +
> +	axiom = axiom_probe(&axiom_i2c_bus_ops, &client->dev, client->irq);
> +	if (IS_ERR(axiom))
> +		return dev_err_probe(&client->dev, PTR_ERR(axiom),
> +				     "failed to register input device\n");
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id axiom_i2c_id_table[] = {
> +	{ "axiom-i2c" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
> +
> +static const struct of_device_id axiom_i2c_dt_ids[] = {
> +	{
> +		.compatible = "tnx,axiom-i2c",
> +		.data = "axiom",
> +	},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, axiom_i2c_dt_ids);
> +
> +static struct i2c_driver axiom_i2c_driver = {
> +	.driver = {
> +		.name = "axiom_i2c",
> +		.of_match_table = of_match_ptr(axiom_i2c_dt_ids),
> +	},
> +	.id_table = axiom_i2c_id_table,
> +	.probe = axiom_i2c_probe,
> +};
> +
> +module_i2c_driver(axiom_i2c_driver);
> +
> +MODULE_AUTHOR("TouchNetix <support@touchnetix.com>");
> +MODULE_DESCRIPTION("aXiom touchscreen I2C bus driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("axiom");
> +MODULE_VERSION("1.0.0");
> diff --git a/drivers/input/touchscreen/axiom_spi.c b/drivers/input/touchscreen/axiom_spi.c
> new file mode 100644
> index 000000000000..a67ad3645689
> --- /dev/null
> +++ b/drivers/input/touchscreen/axiom_spi.c
> @@ -0,0 +1,159 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * TouchNetix aXiom Touchscreen Driver
> + *
> + * Copyright (C) 2018-2023 TouchNetix Ltd.
> + *
> + * Author(s): Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
> + *            Bart Prescott <bartp@baasheep.co.uk>
> + *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
> + *            Andrew Thomas <andrew.thomas@touchnetix.com>
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + *
> + */
> +
> +// #define DEBUG // Enable debug messages
> +
> +#include <linux/of.h>
> +#include <linux/kernel.h>
> +#include <linux/delay.h>
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +#include <linux/input.h>
> +#include "axiom_core.h"
> +
> +#define SPI_PADDING_LEN 32
> +
> +static int axiom_spi_transfer(struct device *dev, enum ax_comms_op_e op,
> +			      u16 addr, u16 length, void *values)
> +{
> +	int ret;
> +	struct spi_device *spi = to_spi_device(dev);
> +	struct spi_transfer xfr_header;
> +	struct spi_transfer xfr_padding;
> +	struct spi_transfer xfr_payload;
> +	struct spi_message msg;
> +	struct axiom_cmd_header cmd_header = { .target_address = addr,
> +					       .length = length,
> +					       .rd_wr = op };
> +	u8 pad_buf[SPI_PADDING_LEN] = { 0 };
> +
> +	memset(&xfr_header, 0, sizeof(xfr_header));
> +	memset(&xfr_padding, 0, sizeof(xfr_padding));
> +	memset(&xfr_payload, 0, sizeof(xfr_payload));
> +
> +	/* Setup the SPI transfer operations */
> +	xfr_header.tx_buf = &cmd_header;
> +	xfr_header.len = sizeof(cmd_header);
> +
> +	xfr_padding.tx_buf = pad_buf;
> +	xfr_padding.len = sizeof(pad_buf);
> +
> +	switch (op) {
> +	case AX_WR_OP:
> +		xfr_payload.tx_buf = values;
> +		break;
> +	case AX_RD_OP:
> +		xfr_payload.rx_buf = values;
> +		break;
> +	default:
> +		dev_err(dev, "%s: invalid operation: %d\n", __func__, op);
> +		return -EINVAL;
> +	}
> +	xfr_payload.len = length;
> +
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfr_header, &msg);
> +	spi_message_add_tail(&xfr_padding, &msg);
> +	spi_message_add_tail(&xfr_payload, &msg);
> +
> +	ret = spi_sync(spi, &msg);
> +	if (ret < 0) {
> +		dev_err(&spi->dev, "Failed to SPI transfer, error: %d\n", ret);
> +		return ret;
> +	}
> +
> +	udelay(AXIOM_HOLDOFF_DELAY_US);
> +
> +	return 0;
> +}
> +
> +static int axiom_spi_read_block_data(struct device *dev, u16 addr, u16 length,
> +				     void *values)
> +{
> +	return axiom_spi_transfer(dev, AX_RD_OP, addr, length, values);
> +}
> +
> +static int axiom_spi_write_block_data(struct device *dev, u16 addr, u16 length,
> +				      void *values)
> +{
> +	return axiom_spi_transfer(dev, AX_WR_OP, addr, length, values);
> +}
> +
> +static const struct axiom_bus_ops axiom_spi_bus_ops = {
> +	.bustype = BUS_SPI,
> +	.write = axiom_spi_write_block_data,
> +	.read = axiom_spi_read_block_data,
> +};
> +
> +static int axiom_spi_probe(struct spi_device *spi)
> +{
> +	struct axiom *axiom;
> +	int error;
> +
> +	/* Set up SPI */
> +	spi->bits_per_word = 8;
> +	spi->mode = SPI_MODE_0;
> +	spi->max_speed_hz = 4000000;
> +
> +	if (spi->irq == 0)
> +		dev_err(&spi->dev, "No IRQ specified!\n");
> +
> +	error = spi_setup(spi);
> +	if (error < 0) {
> +		dev_err(&spi->dev, "%s: SPI setup error %d\n", __func__, error);
> +		return error;
> +	}
> +	axiom = axiom_probe(&axiom_spi_bus_ops, &spi->dev, spi->irq);
> +	if (IS_ERR(axiom))
> +		return dev_err_probe(&spi->dev, PTR_ERR(axiom),
> +				     "failed to register input device\n");
> +
> +	return 0;
> +}
> +
> +static const struct spi_device_id axiom_spi_id_table[] = {
> +	{ "axiom-spi" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(spi, axiom_spi_id_table);
> +
> +static const struct of_device_id axiom_spi_dt_ids[] = {
> +	{
> +		.compatible = "tnx,axiom-spi",
> +		.data = "axiom",
> +	},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, axiom_spi_dt_ids);
> +
> +static struct spi_driver axiom_spi_driver = {
> +	.id_table = axiom_spi_id_table,
> +	.driver = {
> +		.name = "axiom_spi",
> +		.of_match_table = of_match_ptr(axiom_spi_dt_ids),
> +	},
> +	.probe = axiom_spi_probe,
> +};
> +
> +module_spi_driver(axiom_spi_driver);
> +
> +MODULE_AUTHOR("TouchNetix <support@touchnetix.com>");
> +MODULE_DESCRIPTION("aXiom touchscreen SPI bus driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("axiom");
> +MODULE_VERSION("1.0.0");
> -- 
> 2.43.0
> 
> 

-- 
#gernperDu 
#CallMeByMyFirstName

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Re: [PATCH 1/1] Adding support for aXiom touchscreen controller

[Andrew Thomas]

Hi Marco,
Thank you very much for your quick review.
I have addressed many of your comments below.

> > +config TOUCHSCREEN_AXIOM_CORE
> > + tristate "TouchNetix Axiom touchscreen"
>
> Nack, the spi or i2c should select the core.
>

Changed.

> > +#define U41_COORD_SIZE (4)
> > +#define U41_Z_OFFSET (42)
>
> Align your defines.
>

Changed.

> > + input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
> > + input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
> > + input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
>
> Max values are coming from the firmware.
>

I am trying to keep the initial patch as simple as possible.
This is a fixed value describedin the usage definition.

> > +
> > + input_mt_init_slots(input_dev, U41_MAX_TARGETS, INPUT_MT_DIRECT);
>
> num-targets can be configured via firmware config IIRC, so nack.
>

That is correct, all u41 can be configured separately.
As above, I wish the keep this patch as simple as possible so we can
add support for this in the future.

> > + err = ax->bus_ops->read(ax->dev, 0x0, SIZE_U31_DEVICE_INFO,
> > + ax->read_buf);
>
> No need for custom accessors, use regmap API.
>

From my understanding the the interface is the same.
Manual I2C/SPI bus handling is still required.

> > + ax->bus_ops = bus_ops;
> > + ax->irq = irq;
>
> You allocate absolute no ext. resources like regulators or reset-gpios.
>

If you think this would be needed in order for you to test this patch
we can add it.
As above, I wish the patch to a minimal support of I2C and SPI and furthur
features can be added ontop.

>
> > + switch (hdr.report_usage) {
> > + case AX_2DCTS_REPORT_ID:
> > + err = axiom_process_u41_report(ax,
> > + &report[AX_U34_PAYLOAD_BUFFER]);
>
> May I ask why you guys write in your programming manual, that the host
> needs to check the usage-revision and you completely ignore this?

As above.
all usage revisions will handle this identically.


Regards,
Andrew

Re: [PATCH 1/1] Adding support for aXiom touchscreen controller

[Krzysztof Kozlowski]

On 22/01/2026 13:48, AThomas63 wrote:
> Signed-off-by: AThomas63 <andrew.thomas@touchnetix.com>


Please run scripts/checkpatch.pl on the patches and fix reported
warnings. After that, run also 'scripts/checkpatch.pl --strict' on the
patches and (probably) fix more warnings. Some warnings can be ignored,
especially from --strict run, but the code here looks like it needs a
fix. Feel free to get in touch if the warning is not clear.

Running checkpatch is really basic and EVERY kernel guide asks you to do
that. Not doing it is not an excuse for your first patch, becasue when
writing first patch you should follow the first-patch guidelines or
kernel docs closely.


> ---
>  drivers/input/touchscreen/Kconfig      |  30 ++
>  drivers/input/touchscreen/Makefile     |   3 +
>  drivers/input/touchscreen/axiom_core.c | 482 +++++++++++++++++++++++++
>  drivers/input/touchscreen/axiom_core.h | 128 +++++++
>  drivers/input/touchscreen/axiom_i2c.c  | 152 ++++++++
>  drivers/input/touchscreen/axiom_spi.c  | 159 ++++++++
>  6 files changed, 954 insertions(+)
>  create mode 100644 drivers/input/touchscreen/axiom_core.c
>  create mode 100644 drivers/input/touchscreen/axiom_core.h
>  create mode 100644 drivers/input/touchscreen/axiom_i2c.c
>  create mode 100644 drivers/input/touchscreen/axiom_spi.c
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 7d5b72ee07fa..f2b4fb317bdd 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -162,6 +162,36 @@ config TOUCHSCREEN_AUO_PIXCIR
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called auo-pixcir-ts.
>  
> +config TOUCHSCREEN_AXIOM_CORE
> +	tristate "TouchNetix Axiom touchscreen"

This should not be user-selectable. It's useless alone. Just "tristate"
and change the depending drivers to select it.

> +	help
> +	  Say Y here if you have an Axiom touchscreen connected
> +	  to your system. You will also need to select appropriate
> +	  bus connection below.
> +
> +	  If unsure, say N.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called axiom_core.
> +
> +config TOUCHSCREEN_AXIOM_I2C
> +	tristate "support I2C bus connection"
> +	depends on TOUCHSCREEN_AXIOM_CORE && I2C
> +	help
> +	  Say Y here if the touchscreen is connected via I2C bus.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called axiom_spi.
> +
> +config TOUCHSCREEN_AXIOM_SPI
> +	tristate "support SPI bus connection"
> +	depends on TOUCHSCREEN_AXIOM_CORE && SPI
> +	help
> +	  Say Y here if the touchscreen is connected via SPI bus.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called axiom_spi.
> +


...

> + *
> + * Author(s): Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
> + *            Bart Prescott <bartp@baasheep.co.uk>
> + *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
> + *            Andrew Thomas <andrew.thomas@touchnetix.com>
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.

No code in the kernel has such license boilerplate. Please use recent
Linux drivers as starting code. It's really pointless to send to
upstream some old vendor code, because you will repeat all the
mistakes/issues/old style which we fixed already over last 15 years.

> + *


...

> +
> +static const struct spi_device_id axiom_spi_id_table[] = {
> +	{ "axiom-spi" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(spi, axiom_spi_id_table);
> +
> +static const struct of_device_id axiom_spi_dt_ids[] = {
> +	{
> +		.compatible = "tnx,axiom-spi",
> +		.data = "axiom",
> +	},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, axiom_spi_dt_ids);
> +
> +static struct spi_driver axiom_spi_driver = {
> +	.id_table = axiom_spi_id_table,
> +	.driver = {
> +		.name = "axiom_spi",
> +		.of_match_table = of_match_ptr(axiom_spi_dt_ids),

Drop of_match_ptr, leads to warnings here.

> +	},
> +	.probe = axiom_spi_probe,
> +};
> +
> +module_spi_driver(axiom_spi_driver);
> +
> +MODULE_AUTHOR("TouchNetix <support@touchnetix.com>");
> +MODULE_DESCRIPTION("aXiom touchscreen SPI bus driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("axiom");

Drop alias. You should not need MODULE_ALIAS() in normal cases. If you
need it, usually it means your device ID table is wrong (e.g. misses
either entries or MODULE_DEVICE_TABLE()). MODULE_ALIAS() is not a
substitute for incomplete ID table.

> +MODULE_VERSION("1.0.0");


Best regards,
Krzysztof

[PATCH v1] dt-bindings: input: Add TouchNetix aXiom touchscreen driver

[AThomas63]

Add extra changes referenced in the previous patch:
 - Add device tree documentation for axiom giving examples for SPI and I2C.
 - Add tnx vendor prefix.

---
 .../bindings/input/touchscreen/tnx,axiom.yaml | 90 +++++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |  2 +
 2 files changed, 92 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml

diff --git a/Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml b/Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml
new file mode 100644
index 000000000000..dc2ea62999b8
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml
@@ -0,0 +1,90 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/tnx,axiom.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TouchNetix aXiom Touchscreen Controller
+
+maintainers:
+  - Andrew Thomas <andrew.thomas@touchnetix.com>
+
+description: |
+  The TouchNetix aXiom series are high-performance touchscreen controllers
+  supporting various interface methods including I2C and SPI.
+
+properties:
+  compatible:
+    enum:
+      - tnx,axiom-i2c
+      - tnx,axiom-spi
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  axiom,poll-enable:
+    type: boolean
+    description: Enable aXiom polling mode instead of interrupt-driven 
+      reporting.
+
+  axiom,poll-period:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 10
+    description: Set the polling period in milliseconds.
+
+  # Required for SPI
+  spi-max-frequency: true
+
+  # Common touchscreen properties
+  touchscreen-size-x: true
+  touchscreen-size-y: true
+  touchscreen-inverted-x: true
+  touchscreen-inverted-y: true
+  touchscreen-swapped-x-y: true
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+allOf:
+  - $ref: touchscreen.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        touchscreen@66 {
+            compatible = "touchnetix,axiom-i2c";
+            reg = <0x66>;
+            interrupt-parent = <&gpio>;
+            interrupts = <24 IRQ_TYPE_LEVEL_LOW>;
+            axiom,poll-enable;
+            axiom,poll-period = <15>;
+        };
+    };
+
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        touchscreen@0 {
+            compatible = "touchnetix,axiom-spi";
+            reg = <0>;
+            spi-max-frequency = <4000000>;
+            interrupt-parent = <&gpio>;
+            interrupts = <24 IRQ_TYPE_LEVEL_LOW>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index f1d1882009ba..dadfc7036ed7 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1636,6 +1636,8 @@ patternProperties:
     description: Trusted Logic Mobility
   "^tmt,.*":
     description: Tecon Microprocessor Technologies, LLC.
+  "^tnx,.*":
+    description: TouchNetix
   "^topeet,.*":
     description: Topeet
   "^topic,.*":
-- 
2.43.0

Re: [PATCH v1] dt-bindings: input: Add TouchNetix aXiom touchscreen driver

[Krzysztof Kozlowski]

On 22/01/2026 15:40, AThomas63 wrote:
> Add extra changes referenced in the previous patch:

Not relevant.


>  - Add device tree documentation for axiom giving examples for SPI and I2C.
>  - Add tnx vendor prefix.

Please start using b4 or use known (described) workflows with git. Look
at the subject - why is this just one patch not 1/2? Patchsets are made
git format-patch -2 (-vX if needed).

And then:
Please use scripts/get_maintainers.pl to get a list of necessary people
and lists to CC. It might happen, that command when run on an older
kernel, gives you outdated entries. Therefore please be sure you base
your patches on recent Linux kernel.

Tools like b4 or scripts/get_maintainer.pl provide you proper list of
people, so fix your workflow. Tools might also fail if you work on some
ancient tree (don't, instead use mainline) or work on fork of kernel
(don't, instead use mainline). Just use b4 and everything should be
fine, although remember about `b4 prep --auto-to-cc` if you added new
patches to the patchset.

You missed at least devicetree list (maybe more), so this won't be
tested by automated tooling. Performing review on untested code might be
a waste of time.

Please kindly resend and include all necessary To/Cc entries.


> 
> ---
>  .../bindings/input/touchscreen/tnx,axiom.yaml | 90 +++++++++++++++++++
>  .../devicetree/bindings/vendor-prefixes.yaml  |  2 +
>  2 files changed, 92 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml b/Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml
> new file mode 100644
> index 000000000000..dc2ea62999b8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml
> @@ -0,0 +1,90 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/touchscreen/tnx,axiom.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TouchNetix aXiom Touchscreen Controller
> +
> +maintainers:
> +  - Andrew Thomas <andrew.thomas@touchnetix.com>
> +
> +description: |


> +  The TouchNetix aXiom series are high-performance touchscreen controllers
> +  supporting various interface methods including I2C and SPI.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - tnx,axiom-i2c
> +      - tnx,axiom-spi

No, these are the same. Use only one describing the device.

No device model? Really?

> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  axiom,poll-enable:

There is no such company as axiom. You just said it is tnx.
> +    type: boolean
> +    description: Enable aXiom polling mode instead of interrupt-driven 
> +      reporting.

Anyway, drop entire property. Not a DT suitable, not hardware.

> +
> +  axiom,poll-period:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 10
> +    description: Set the polling period in milliseconds.

Drop entire property.

> +
> +  # Required for SPI
> +  spi-max-frequency: true

Drop. Not needed.

> +
> +  # Common touchscreen properties
> +  touchscreen-size-x: true
> +  touchscreen-size-y: true
> +  touchscreen-inverted-x: true
> +  touchscreen-inverted-y: true
> +  touchscreen-swapped-x-y: true

Drop all.

> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +
> +allOf:
> +  - $ref: touchscreen.yaml#

Missing ref to spi-periph.

Look at other bindings instead of inventing your own.

> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        touchscreen@66 {
> +            compatible = "touchnetix,axiom-i2c";
> +            reg = <0x66>;
> +            interrupt-parent = <&gpio>;
> +            interrupts = <24 IRQ_TYPE_LEVEL_LOW>;
> +            axiom,poll-enable;
> +            axiom,poll-period = <15>;
> +        };
> +    };
> +
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        touchscreen@0 {
> +            compatible = "touchnetix,axiom-spi";
> +            reg = <0>;
> +            spi-max-frequency = <4000000>;
> +            interrupt-parent = <&gpio>;
> +            interrupts = <24 IRQ_TYPE_LEVEL_LOW>;
> +        };
> +    };
> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> index f1d1882009ba..dadfc7036ed7 100644
> --- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
> +++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> @@ -1636,6 +1636,8 @@ patternProperties:
>      description: Trusted Logic Mobility
>    "^tmt,.*":
>      description: Tecon Microprocessor Technologies, LLC.
> +  "^tnx,.*":

Domain is touchnetix, so that's your prefix.

> +    description: TouchNetix
>    "^topeet,.*":
>      description: Topeet
>    "^topic,.*":


Best regards,
Krzysztof

Re: [PATCH v1] dt-bindings: input: Add TouchNetix aXiom touchscreen driver

[Marco Felsch]

Hi Krzysztof,

On 26-01-23, Krzysztof Kozlowski wrote:
> On 22/01/2026 15:40, AThomas63 wrote:
> > Add extra changes referenced in the previous patch:

...

> > +properties:
> > +  compatible:
> > +    enum:
> > +      - tnx,axiom-i2c
> > +      - tnx,axiom-spi
> 
> No, these are the same. Use only one describing the device.
> 
> No device model? Really?

That beeing said, you already provided your review for a device which is
part of this family here:
 - https://lore.kernel.org/all/20260111-v6-10-topic-touchscreen-axiom-v5-3-f94e0ae266cb@pengutronix.de/

Regards,
  Marco

> 
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  axiom,poll-enable:
> 
> There is no such company as axiom. You just said it is tnx.
> > +    type: boolean
> > +    description: Enable aXiom polling mode instead of interrupt-driven 
> > +      reporting.
> 
> Anyway, drop entire property. Not a DT suitable, not hardware.
> 
> > +
> > +  axiom,poll-period:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    default: 10
> > +    description: Set the polling period in milliseconds.
> 
> Drop entire property.
> 
> > +
> > +  # Required for SPI
> > +  spi-max-frequency: true
> 
> Drop. Not needed.
> 
> > +
> > +  # Common touchscreen properties
> > +  touchscreen-size-x: true
> > +  touchscreen-size-y: true
> > +  touchscreen-inverted-x: true
> > +  touchscreen-inverted-y: true
> > +  touchscreen-swapped-x-y: true
> 
> Drop all.
> 
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +
> > +allOf:
> > +  - $ref: touchscreen.yaml#
> 
> Missing ref to spi-periph.
> 
> Look at other bindings instead of inventing your own.
> 
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +
> > +    i2c {
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        touchscreen@66 {
> > +            compatible = "touchnetix,axiom-i2c";
> > +            reg = <0x66>;
> > +            interrupt-parent = <&gpio>;
> > +            interrupts = <24 IRQ_TYPE_LEVEL_LOW>;
> > +            axiom,poll-enable;
> > +            axiom,poll-period = <15>;
> > +        };
> > +    };
> > +
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +
> > +    spi {
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        touchscreen@0 {
> > +            compatible = "touchnetix,axiom-spi";
> > +            reg = <0>;
> > +            spi-max-frequency = <4000000>;
> > +            interrupt-parent = <&gpio>;
> > +            interrupts = <24 IRQ_TYPE_LEVEL_LOW>;
> > +        };
> > +    };
> > diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > index f1d1882009ba..dadfc7036ed7 100644
> > --- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > +++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > @@ -1636,6 +1636,8 @@ patternProperties:
> >      description: Trusted Logic Mobility
> >    "^tmt,.*":
> >      description: Tecon Microprocessor Technologies, LLC.
> > +  "^tnx,.*":
> 
> Domain is touchnetix, so that's your prefix.
> 
> > +    description: TouchNetix
> >    "^topeet,.*":
> >      description: Topeet
> >    "^topic,.*":
> 
> 
> Best regards,
> Krzysztof
> 

-- 
#gernperDu 
#CallMeByMyFirstName

Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | https://www.pengutronix.de/ |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-9    |

Re: [PATCH v1] dt-bindings: input: Add TouchNetix aXiom touchscreen driver

[Andrew Thomas]

Hi Krzysztof,
Thank you for the quick review and giving me a lot to look into straight away!
I shall resubmit my patch correctly using b4 in a separate email.

> > + The TouchNetix aXiom series are high-performance touchscreen controllers
> > + supporting various interface methods including I2C and SPI.
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - tnx,axiom-i2c
> > + - tnx,axiom-spi
> 
> No, these are the same. Use only one describing the device.
> 

Fixed.

> No device model? Really?

There are device models, but all devices use a very similar interface which
just changes with revision.

> > +allOf:
> > +  - $ref: touchscreen.yaml#
> 
> Missing ref to spi-periph.
> 
> Look at other bindings instead of inventing your own.

Added.

> > +
> > + reg:
> > + maxItems: 1
> > +
> > + interrupts:
> > + maxItems: 1
> > +
> > + axiom,poll-enable:
> 
> There is no such company as axiom. You just said it is tnx.
> 
> > + type: boolean
> > + description: Enable aXiom polling mode instead of interrupt-driven
> > + reporting.
> 
> Anyway, drop entire property. Not a DT suitable, not hardware.

Removed polling from device tree and added as a module_param.

Many Thanks,
Andrew

Re: [PATCH v1] dt-bindings: input: Add TouchNetix aXiom touchscreen driver

[Krzysztof Kozlowski]

On 22/01/2026 15:40, AThomas63 wrote:
> Add extra changes referenced in the previous patch:
>  - Add device tree documentation for axiom giving examples for SPI and I2C.
>  - Add tnx vendor prefix.

Incomplete DCO chain.

Please run scripts/checkpatch.pl on the patches and fix reported
warnings. After that, run also 'scripts/checkpatch.pl --strict' on the
patches and (probably) fix more warnings. Some warnings can be ignored,
especially from --strict run, but the code here looks like it needs a
fix. Feel free to get in touch if the warning is not clear.

Also, no anonymous contributions. It's also explicitly documented.


Best regards,
Krzysztof

Re: [PATCH 0/1] Input: Add TouchNetix aXiom touchscreen driver

[Marco Felsch]

Hi Andrew,

thanks for your patch.

A few words prior doing a very rough review. I don't like the idea of
posting two complete different patchsets, furthermore if you could have
added the missing SPI support on-top of my patchset very easily since I
used the regmap-API.

Most of my patches already got the r-b tags and I received a very good
review from Dmitry recently which I currently integrating to send a new
version.

On 26-01-22, AThomas63 wrote:
> A Summary of the added features:
>  - Add input driver support for TouchNetix aXiom touchscreen controller 
> using either I2C or SPI.
>  - Support ABS_MT touch reports in axiom_process_u41_report().
>  - Support both polling and interrupt mode (trigger low).
>  - Add basic documentation and provide example device tree bindings.
>  - Provide the basic structure to add firmware and config download in
> the future via both I2C and SPI.
> 
> I understand the process is already under way to add a driver to support 
> aXiom by Marco at Pengutronix.
> I think it would be most useful for us to attempt to combine this patch
> in order to support both his changes for config/firmware download and 
> the patch here for SPI support along with I2C. I would be happy to help 
> with this process.
> This would allow TouchNetix to support a broader range of users of the
> aXiom device family.
> 
> I also have a device tree binding however I have not added it sincec
> from my understanding this should go in a different patch:
> Documentation/devicetree/bindings/input/touchscreen/tnx,axiom.yaml
>  
> My apologies if there are any obvious mistakes in this patch, this is the
> first patch that I have submitted.

That's not a problem at least not for me, but there are contriubtion
guidelines which you could have read first.

Also I'm a bit surprised that you have sent a driver for the same device
family which is less capable than mine. Your driver is missing the
complete fw-update mechanism and therefore needs still your downstream
python tooling. The fw-update logic is a huge part, since this was hard
to get it right.

There are a few other parts, you're doing wrong (please see the patch
review).

Regards,
  Marco


> 
> Many thanks for your time,
> Andrew Thomas
> 
> AThomas63 (1):
>   Adding support for aXiom touchscreen controller
> 
>  drivers/input/touchscreen/Kconfig      |  30 ++
>  drivers/input/touchscreen/Makefile     |   3 +
>  drivers/input/touchscreen/axiom_core.c | 482 +++++++++++++++++++++++++
>  drivers/input/touchscreen/axiom_core.h | 128 +++++++
>  drivers/input/touchscreen/axiom_i2c.c  | 152 ++++++++
>  drivers/input/touchscreen/axiom_spi.c  | 159 ++++++++
>  6 files changed, 954 insertions(+)
>  create mode 100644 drivers/input/touchscreen/axiom_core.c
>  create mode 100644 drivers/input/touchscreen/axiom_core.h
>  create mode 100644 drivers/input/touchscreen/axiom_i2c.c
>  create mode 100644 drivers/input/touchscreen/axiom_spi.c
> 
> -- 
> 2.43.0
> 
> 

-- 
#gernperDu 
#CallMeByMyFirstName

Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | https://www.pengutronix.de/ |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-9    |