[PATCH v5 2/2] Input: Add support for Wacom W9000-series penabled touchscreens

[Hendrik Noack <hendrik-noack@gmx.de>]

Add driver for Wacom W9002 and two Wacom W9007A variants. These are
penabled touchscreens supporting passive Wacom Pens and use I2C.

Co-developed-by: Ferass El Hafidi <funderscore@postmarketos.org>
Signed-off-by: Ferass El Hafidi <funderscore@postmarketos.org>
Signed-off-by: Hendrik Noack <hendrik-noack@gmx.de>
---
 drivers/input/touchscreen/Kconfig       |  12 +
 drivers/input/touchscreen/Makefile      |   1 +
 drivers/input/touchscreen/wacom_w9000.c | 433 ++++++++++++++++++++++++
 3 files changed, 446 insertions(+)
 create mode 100644 drivers/input/touchscreen/wacom_w9000.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 7d5b72ee07fa..a28328fb7648 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -610,6 +610,18 @@ config TOUCHSCREEN_WACOM_I2C
 	  To compile this driver as a module, choose M here: the module
 	  will be called wacom_i2c.
 
+config TOUCHSCREEN_WACOM_W9000
+	tristate "Wacom W9000-series penabled touchscreen (I2C)"
+	depends on I2C
+	help
+	  Say Y here if you have a Wacom W9000-series penabled I2C touchscreen.
+	  This driver supports models W9002 and W9007A.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called wacom_w9000.
+
 config TOUCHSCREEN_LPC32XX
 	tristate "LPC32XX touchscreen controller"
 	depends on ARCH_LPC32XX
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index ab9abd151078..aa3915df83b2 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -102,6 +102,7 @@ tsc2007-$(CONFIG_TOUCHSCREEN_TSC2007_IIO)	+= tsc2007_iio.o
 obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o
 obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)	+= wacom_w8001.o
 obj-$(CONFIG_TOUCHSCREEN_WACOM_I2C)	+= wacom_i2c.o
+obj-$(CONFIG_TOUCHSCREEN_WACOM_W9000)	+= wacom_w9000.o
 obj-$(CONFIG_TOUCHSCREEN_WDT87XX_I2C)	+= wdt87xx_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_WM831X)	+= wm831x-ts.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX)	+= wm97xx-ts.o
diff --git a/drivers/input/touchscreen/wacom_w9000.c b/drivers/input/touchscreen/wacom_w9000.c
new file mode 100644
index 000000000000..f431e03a2b7a
--- /dev/null
+++ b/drivers/input/touchscreen/wacom_w9000.c
@@ -0,0 +1,433 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Wacom W9000-series penabled I2C touchscreen driver
+ *
+ * Copyright (c) 2026 Hendrik Noack <hendrik-noack@gmx.de>
+ *
+ * Partially based on vendor driver:
+ *	Copyright (C) 2012, Samsung Electronics Co. Ltd.
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/touchscreen.h>
+#include <linux/unaligned.h>
+
+/* Some chips have flaky firmware that requires many retries before responding. */
+#define CMD_QUERY_RETRIES	8
+
+/* Message length */
+#define CMD_QUERY_NUM_MAX	9
+#define MSG_COORD_NUM_MAX	12
+
+/* Commands */
+#define CMD_QUERY		0x2a
+
+struct wacom_w9000_variant {
+	const unsigned int cmd_query_num;
+	const unsigned int msg_coord_num;
+	const char *name;
+};
+
+struct wacom_w9000_data {
+	struct i2c_client *client;
+	struct input_dev *input_dev;
+	const struct wacom_w9000_variant *variant;
+	unsigned int fw_version;
+
+	struct touchscreen_properties prop;
+	unsigned int max_pressure;
+
+	struct regulator *regulator;
+	bool powered;
+
+	struct gpio_desc *flash_mode_gpio;
+	struct gpio_desc *reset_gpio;
+
+	unsigned int irq;
+
+	bool pen_proximity;
+};
+
+static int wacom_w9000_read(struct i2c_client *client, u8 command, int len, char *data)
+{
+	int error, res;
+	struct i2c_msg msg[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.buf = &command,
+			.len = sizeof(command),
+		}, {
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.buf = data,
+			.len = len,
+		}
+	};
+
+	res = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+	if (res != ARRAY_SIZE(msg)) {
+		error = res < 0 ? res : -EIO;
+		dev_err(&client->dev, "%s: i2c transfer failed: %d (%d)\n", __func__, error, res);
+		return error;
+	}
+
+	return 0;
+}
+
+static int wacom_w9000_query(struct wacom_w9000_data *wacom_data)
+{
+	struct i2c_client *client = wacom_data->client;
+	struct device *dev = &wacom_data->client->dev;
+	int error;
+	int retry = 0;
+	u8 data[CMD_QUERY_NUM_MAX];
+
+	for (; retry < CMD_QUERY_RETRIES; retry++) {
+		error = wacom_w9000_read(client, CMD_QUERY, wacom_data->variant->cmd_query_num,
+					 data);
+
+		if (!error && (data[0] == 0x0f))
+			break;
+	}
+
+	if (error)
+		return error;
+
+	dev_dbg(dev, "query: %*ph, %d\n", wacom_data->variant->cmd_query_num, data, retry);
+
+	wacom_data->prop.max_x = get_unaligned_be16(&data[1]);
+	wacom_data->prop.max_y = get_unaligned_be16(&data[3]);
+	wacom_data->max_pressure = get_unaligned_be16(&data[5]);
+	wacom_data->fw_version = get_unaligned_be16(&data[7]);
+
+	dev_dbg(dev, "max_x:%d, max_y:%d, max_pressure:%d, fw:%#x", wacom_data->prop.max_x,
+		wacom_data->prop.max_y, wacom_data->max_pressure,
+		wacom_data->fw_version);
+
+	return 0;
+}
+
+/* Must be called with wacom_data->input_dev->mutex held */
+static int wacom_w9000_power_on(struct wacom_w9000_data *wacom_data)
+{
+	int error;
+
+	if (wacom_data->powered)
+		return 0;
+
+	error = regulator_enable(wacom_data->regulator);
+	if (error) {
+		dev_err(&wacom_data->client->dev, "Failed to enable regulators: %d\n", error);
+		return error;
+	}
+
+	msleep(200);
+
+	gpiod_set_value_cansleep(wacom_data->reset_gpio, 0);
+	enable_irq(wacom_data->irq);
+
+	wacom_data->powered = true;
+
+	return error;
+}
+
+/* Must be called with wacom_data->input_dev->mutex held */
+static int wacom_w9000_power_off(struct wacom_w9000_data *wacom_data)
+{
+	if (!wacom_data->powered)
+		return 0;
+
+	disable_irq(wacom_data->irq);
+	gpiod_set_value_cansleep(wacom_data->reset_gpio, 1);
+	regulator_disable(wacom_data->regulator);
+
+	wacom_data->powered = false;
+
+	return 0;
+}
+
+static void wacom_w9000_coord(struct wacom_w9000_data *wacom_data)
+{
+	struct i2c_client *client = wacom_data->client;
+	struct device *dev = &wacom_data->client->dev;
+	int error;
+	u8 data[MSG_COORD_NUM_MAX];
+	bool touch, rubber, side_button;
+	u16 x, y, pressure;
+	u8 distance = 0;
+
+	error = i2c_master_recv(client, data, wacom_data->variant->msg_coord_num);
+	if (error != wacom_data->variant->msg_coord_num) {
+		if (error >= 0)
+			error = -EIO;
+		dev_err(dev, "%s: i2c receive failed (%d)\n", __func__, error);
+		return;
+	}
+
+	dev_dbg(dev, "data: %*ph", wacom_data->variant->msg_coord_num, data);
+
+	if (data[0] & BIT(7)) {
+		wacom_data->pen_proximity = true;
+
+		touch = !!(data[0] & BIT(4));
+		side_button = !!(data[0] & BIT(5));
+		rubber = !!(data[0] & BIT(6));
+
+		x = get_unaligned_be16(&data[1]);
+		y = get_unaligned_be16(&data[3]);
+		pressure = get_unaligned_be16(&data[5]);
+
+		if (wacom_data->variant->msg_coord_num > 7)
+			distance = data[7];
+
+		if (x > wacom_data->prop.max_x || y > wacom_data->prop.max_y) {
+			dev_warn(dev, "Coordinates out of range x=%d, y=%d", x, y);
+			return;
+		}
+
+		touchscreen_report_pos(wacom_data->input_dev, &wacom_data->prop, x, y, false);
+		input_report_abs(wacom_data->input_dev, ABS_PRESSURE, pressure);
+
+		if (wacom_data->variant->msg_coord_num > 7)
+			input_report_abs(wacom_data->input_dev, ABS_DISTANCE, distance);
+
+		input_report_key(wacom_data->input_dev, BTN_STYLUS, side_button);
+		input_report_key(wacom_data->input_dev, BTN_TOUCH, touch);
+		input_report_key(wacom_data->input_dev, BTN_TOOL_PEN, !rubber);
+		input_report_key(wacom_data->input_dev, BTN_TOOL_RUBBER, rubber);
+		input_sync(wacom_data->input_dev);
+	} else if (wacom_data->pen_proximity) {
+		input_report_abs(wacom_data->input_dev, ABS_PRESSURE, 0);
+
+		if (wacom_data->variant->msg_coord_num > 7)
+			input_report_abs(wacom_data->input_dev, ABS_DISTANCE, 255);
+
+		input_report_key(wacom_data->input_dev, BTN_STYLUS, 0);
+		input_report_key(wacom_data->input_dev, BTN_TOUCH, 0);
+		input_report_key(wacom_data->input_dev, BTN_TOOL_PEN, 0);
+		input_report_key(wacom_data->input_dev, BTN_TOOL_RUBBER, 0);
+		input_sync(wacom_data->input_dev);
+
+		wacom_data->pen_proximity = false;
+	}
+}
+
+static irqreturn_t wacom_w9000_interrupt(int irq, void *dev_id)
+{
+	struct wacom_w9000_data *wacom_data = dev_id;
+
+	wacom_w9000_coord(wacom_data);
+
+	return IRQ_HANDLED;
+}
+
+static int wacom_w9000_open(struct input_dev *dev)
+{
+	struct wacom_w9000_data *wacom_data = input_get_drvdata(dev);
+
+	return wacom_w9000_power_on(wacom_data);
+}
+
+static void wacom_w9000_close(struct input_dev *dev)
+{
+	struct wacom_w9000_data *wacom_data = input_get_drvdata(dev);
+
+	wacom_w9000_power_off(wacom_data);
+}
+
+static int wacom_w9000_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct wacom_w9000_data *wacom_data;
+	struct input_dev *input_dev;
+	int error;
+	u32 val;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(dev, "i2c_check_functionality error\n");
+		return -EIO;
+	}
+
+	wacom_data = devm_kzalloc(dev, sizeof(*wacom_data), GFP_KERNEL);
+	if (!wacom_data)
+		return -ENOMEM;
+
+	wacom_data->variant = i2c_get_match_data(client);
+
+	if (wacom_data->variant->cmd_query_num > CMD_QUERY_NUM_MAX ||
+	    wacom_data->variant->msg_coord_num > MSG_COORD_NUM_MAX) {
+		dev_err(dev, "Length of message for %s exceeds the maximum\n",
+			wacom_data->variant->name);
+		return -EINVAL;
+	}
+
+	if (wacom_data->variant->msg_coord_num < 7) {
+		dev_err(dev, "Length of coordinates message for %s too short\n",
+			wacom_data->variant->name);
+		return -EINVAL;
+	}
+
+	wacom_data->client = client;
+
+	input_dev = devm_input_allocate_device(dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	wacom_data->input_dev = input_dev;
+	input_set_drvdata(input_dev, wacom_data);
+
+	wacom_data->irq = client->irq;
+	i2c_set_clientdata(client, wacom_data);
+
+	wacom_data->regulator = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(wacom_data->regulator))
+		return dev_err_probe(dev, PTR_ERR(wacom_data->regulator),
+				     "Failed to get regulators\n");
+
+	wacom_data->flash_mode_gpio = devm_gpiod_get_optional(dev, "flash-mode", GPIOD_OUT_LOW);
+	if (IS_ERR(wacom_data->flash_mode_gpio))
+		return dev_err_probe(dev, PTR_ERR(wacom_data->flash_mode_gpio),
+				     "Failed to get flash-mode gpio\n");
+
+	wacom_data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(wacom_data->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(wacom_data->reset_gpio),
+				     "Failed to get reset gpio\n");
+
+	error = regulator_enable(wacom_data->regulator);
+	if (error)
+		return dev_err_probe(dev, error, "Failed to enable regulators\n");
+
+	msleep(200);
+
+	gpiod_set_value_cansleep(wacom_data->reset_gpio, 0);
+
+	error = wacom_w9000_query(wacom_data);
+
+	gpiod_set_value_cansleep(wacom_data->reset_gpio, 1);
+	regulator_disable(wacom_data->regulator);
+
+	wacom_data->powered = false;
+
+	if (error)
+		return dev_err_probe(dev, error, "Failed to query\n");
+
+	input_dev->name = wacom_data->variant->name;
+	input_dev->id.bustype = BUS_I2C;
+	input_dev->dev.parent = dev;
+	input_dev->id.vendor = 0x56a;
+	input_dev->id.version = wacom_data->fw_version;
+	input_dev->open = wacom_w9000_open;
+	input_dev->close = wacom_w9000_close;
+
+	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
+	input_set_capability(input_dev, EV_KEY, BTN_TOOL_PEN);
+	input_set_capability(input_dev, EV_KEY, BTN_TOOL_RUBBER);
+	input_set_capability(input_dev, EV_KEY, BTN_STYLUS);
+
+	input_set_abs_params(input_dev, ABS_X, 0, wacom_data->prop.max_x, 4, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, wacom_data->prop.max_y, 4, 0);
+	input_set_abs_params(input_dev, ABS_PRESSURE, 0, wacom_data->max_pressure, 0, 0);
+
+	if (wacom_data->variant->msg_coord_num > 7)
+		input_set_abs_params(input_dev, ABS_DISTANCE, 0, 255, 0, 0);
+
+	touchscreen_parse_properties(input_dev, false, &wacom_data->prop);
+
+	dev_info(dev, "%s size X%uY%u\n", wacom_data->variant->name,
+		 wacom_data->prop.max_x, wacom_data->prop.max_y);
+
+	error = device_property_read_u32(dev, "touchscreen-x-mm", &val);
+	if (!error)
+		input_abs_set_res(input_dev, ABS_X, wacom_data->prop.max_x / val);
+	error = device_property_read_u32(dev, "touchscreen-y-mm", &val);
+	if (!error)
+		input_abs_set_res(input_dev, ABS_Y, wacom_data->prop.max_y / val);
+
+	error = devm_request_threaded_irq(dev, wacom_data->irq, NULL, wacom_w9000_interrupt,
+					  IRQF_ONESHOT | IRQF_NO_AUTOEN, client->name, wacom_data);
+	if (error)
+		return dev_err_probe(dev, error, "Failed to register interrupt\n");
+
+	error = input_register_device(wacom_data->input_dev);
+	if (error)
+		return dev_err_probe(dev, error, "Failed to register input device\n");
+
+	return 0;
+}
+
+static int wacom_w9000_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct wacom_w9000_data *wacom_data = i2c_get_clientdata(client);
+
+	guard(mutex)(&wacom_data->input_dev->mutex);
+
+	return wacom_w9000_power_off(wacom_data);
+}
+
+static int wacom_w9000_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct wacom_w9000_data *wacom_data = i2c_get_clientdata(client);
+
+	guard(mutex)(&wacom_data->input_dev->mutex);
+
+	return wacom_w9000_power_on(wacom_data);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(wacom_w9000_pm, wacom_w9000_suspend, wacom_w9000_resume);
+
+static const struct wacom_w9000_variant w9002 = {
+	.cmd_query_num  = 9,
+	.msg_coord_num  = 7,
+	.name = "Wacom W9002 Digitizer",
+};
+
+static const struct wacom_w9000_variant w9007a_lt03 = {
+	.cmd_query_num	= 9,
+	.msg_coord_num	= 8,
+	.name = "Wacom W9007A LT03 Digitizer",
+};
+
+static const struct wacom_w9000_variant w9007a_v1 = {
+	.cmd_query_num	= 9,
+	.msg_coord_num	= 12,
+	.name = "Wacom W9007A V1 Digitizer",
+};
+
+static const struct of_device_id wacom_w9000_of_match[] = {
+	{ .compatible = "wacom,w9002", .data = &w9002 },
+	{ .compatible = "wacom,w9007a-lt03", .data = &w9007a_lt03, },
+	{ .compatible = "wacom,w9007a-v1", .data = &w9007a_v1, },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, wacom_w9000_of_match);
+
+static const struct i2c_device_id wacom_w9000_id[] = {
+	{ .name = "w9002", .driver_data = (kernel_ulong_t)&w9002 },
+	{ .name = "w9007a-lt03", .driver_data = (kernel_ulong_t)&w9007a_lt03 },
+	{ .name = "w9007a-v1", .driver_data = (kernel_ulong_t)&w9007a_v1 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, wacom_w9000_id);
+
+static struct i2c_driver wacom_w9000_driver = {
+	.driver = {
+		.name	= "wacom_w9000",
+		.of_match_table = wacom_w9000_of_match,
+		.pm	= pm_sleep_ptr(&wacom_w9000_pm),
+	},
+	.probe		= wacom_w9000_probe,
+	.id_table	= wacom_w9000_id,
+};
+module_i2c_driver(wacom_w9000_driver);
+
+/* Module information */
+MODULE_AUTHOR("Hendrik Noack <hendrik-noack@gmx.de>");
+MODULE_DESCRIPTION("Wacom W9000-series penabled touchscreen driver");
+MODULE_LICENSE("GPL");
-- 
2.43.0