[PATCH v2 2/2] Input: qt1050 - add Microchip AT42QT1050 support

[Marco Felsch <m.felsch@pengutronix.de>]

Add initial support for the AT42QT1050 (QT1050) device. The device
supports up to five input keys, dependent on the mode. Since it adds only
the initial support the "1 to 4 keys plus Guard Channel" mode isn't
support.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>

---
Changes:

v2
- drop static key array allocation
- drop OF dependencies
- change fw-layout, so each key is represented by a fw-subnode
- use qt1050_key_regs_data array to specify button <-> register pairs

 drivers/input/keyboard/Kconfig  |  11 +
 drivers/input/keyboard/Makefile |   1 +
 drivers/input/keyboard/qt1050.c | 620 ++++++++++++++++++++++++++++++++
 3 files changed, 632 insertions(+)
 create mode 100644 drivers/input/keyboard/qt1050.c

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 4713957b0cbb..08aba5e7cd93 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -137,6 +137,17 @@ config KEYBOARD_ATKBD_RDI_KEYCODES
 	  right-hand column will be interpreted as the key shown in the
 	  left-hand column.
 
+config KEYBOARD_QT1050
+	tristate "Microchip AT42QT1050 Touch Sensor Chip"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say Y here if you want to use Microchip AT42QT1050 QTouch
+	  Sensor chip as input device.
+
+	  To compile this driver as a module, choose M here:
+	  the module will be called qt1050
+
 config KEYBOARD_QT1070
        tristate "Atmel AT42QT1070 Touch Sensor Chip"
        depends on I2C
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 182e92985dbf..f0291ca39f62 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_KEYBOARD_OPENCORES)	+= opencores-kbd.o
 obj-$(CONFIG_KEYBOARD_PMIC8XXX)		+= pmic8xxx-keypad.o
 obj-$(CONFIG_KEYBOARD_PXA27x)		+= pxa27x_keypad.o
 obj-$(CONFIG_KEYBOARD_PXA930_ROTARY)	+= pxa930_rotary.o
+obj-$(CONFIG_KEYBOARD_QT1050)           += qt1050.o
 obj-$(CONFIG_KEYBOARD_QT1070)           += qt1070.o
 obj-$(CONFIG_KEYBOARD_QT2160)		+= qt2160.o
 obj-$(CONFIG_KEYBOARD_SAMSUNG)		+= samsung-keypad.o
diff --git a/drivers/input/keyboard/qt1050.c b/drivers/input/keyboard/qt1050.c
new file mode 100644
index 000000000000..6d107dfca782
--- /dev/null
+++ b/drivers/input/keyboard/qt1050.c
@@ -0,0 +1,620 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Microchip AT42QT1050 QTouch Sensor Controller
+ *
+ *  Authors: Marco Felsch <kernel@pengutronix.de>
+ *
+ *  Base on AT42QT1070 driver by:
+ *  Bo Shen <voice.shen@atmel.com>
+ *  Copyright (C) 2011 Atmel
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+/* Chip ID */
+#define QT1050_CHIP_ID		0x00
+#define QT1050_CHIP_ID_VER	0x46
+
+/* Firmware version */
+#define QT1050_FW_VERSION	0x01
+
+/* Detection status */
+#define QT1050_DET_STATUS	0x02
+
+/* Key status */
+#define QT1050_KEY_STATUS	0x03
+
+/* Key Signals */
+#define QT1050_KEY_SIGNAL_0_MSB	0x06
+#define QT1050_KEY_SIGNAL_0_LSB	0x07
+#define QT1050_KEY_SIGNAL_1_MSB	0x08
+#define QT1050_KEY_SIGNAL_1_LSB	0x09
+#define QT1050_KEY_SIGNAL_2_MSB	0x0c
+#define QT1050_KEY_SIGNAL_2_LSB	0x0d
+#define QT1050_KEY_SIGNAL_3_MSB	0x0e
+#define QT1050_KEY_SIGNAL_3_LSB	0x0f
+#define QT1050_KEY_SIGNAL_4_MSB	0x10
+#define QT1050_KEY_SIGNAL_4_LSB	0x11
+
+/* Reference data */
+#define QT1050_REF_DATA_0_MSB	0x14
+#define QT1050_REF_DATA_0_LSB	0x15
+#define QT1050_REF_DATA_1_MSB	0x16
+#define QT1050_REF_DATA_1_LSB	0x17
+#define QT1050_REF_DATA_2_MSB	0x1a
+#define QT1050_REF_DATA_2_LSB	0x1b
+#define QT1050_REF_DATA_3_MSB	0x1c
+#define QT1050_REF_DATA_3_LSB	0x1d
+#define QT1050_REF_DATA_4_MSB	0x1e
+#define QT1050_REF_DATA_4_LSB	0x1f
+
+/* Negative threshold level */
+#define QT1050_NTHR_0		0x21
+#define QT1050_NTHR_1		0x22
+#define QT1050_NTHR_2		0x24
+#define QT1050_NTHR_3		0x25
+#define QT1050_NTHR_4		0x26
+
+/* Pulse / Scale  */
+#define QT1050_PULSE_SCALE_0	0x28
+#define QT1050_PULSE_SCALE_1	0x29
+#define QT1050_PULSE_SCALE_2	0x2b
+#define QT1050_PULSE_SCALE_3	0x2c
+#define QT1050_PULSE_SCALE_4	0x2d
+
+/* Detection integrator counter / AKS */
+#define QT1050_DI_AKS_0		0x2f
+#define QT1050_DI_AKS_1		0x30
+#define QT1050_DI_AKS_2		0x32
+#define QT1050_DI_AKS_3		0x33
+#define QT1050_DI_AKS_4		0x34
+
+/* Charge Share Delay */
+#define QT1050_CSD_0		0x36
+#define QT1050_CSD_1		0x37
+#define QT1050_CSD_2		0x39
+#define QT1050_CSD_3		0x3a
+#define QT1050_CSD_4		0x3b
+
+/* Low Power Mode */
+#define QT1050_LPMODE		0x3d
+
+/* Calibration and Reset */
+#define QT1050_RES_CAL		0x3f
+#define QT1050_RES_CAL_RESET		BIT(7)
+#define QT1050_RES_CAL_CALIBRATE	BIT(1)
+
+#define QT1050_MAX_KEYS		5
+#define QT1050_RESET_TIME	255
+
+struct qt1050_key_regs {
+	unsigned int nthr;
+	unsigned int pulse_scale;
+	unsigned int di_aks;
+	unsigned int csd;
+};
+
+struct qt1050_key {
+	int num;
+	u32 charge_delay;
+	u32 thr_cnt;
+	u32 samples;
+	u32 scale;
+	u32 keycode;
+};
+
+struct qt1050_priv {
+	struct i2c_client	*client;
+	struct input_dev	*input;
+	struct regmap		*regmap;
+	struct qt1050_key	*keys;
+	unsigned short		*keycodes;
+	int			num_keys;
+	u8			reg_keys;
+	u8			last_keys;
+};
+
+static const struct qt1050_key_regs qt1050_key_regs_data[] = {
+	{
+		.nthr = QT1050_NTHR_0,
+		.pulse_scale = QT1050_PULSE_SCALE_0,
+		.di_aks = QT1050_DI_AKS_0,
+		.csd = QT1050_CSD_0,
+	}, {
+		.nthr = QT1050_NTHR_1,
+		.pulse_scale = QT1050_PULSE_SCALE_1,
+		.di_aks = QT1050_DI_AKS_1,
+		.csd = QT1050_CSD_1,
+	}, {
+		.nthr = QT1050_NTHR_2,
+		.pulse_scale = QT1050_PULSE_SCALE_2,
+		.di_aks = QT1050_DI_AKS_2,
+		.csd = QT1050_CSD_2,
+	}, {
+		.nthr = QT1050_NTHR_3,
+		.pulse_scale = QT1050_PULSE_SCALE_3,
+		.di_aks = QT1050_DI_AKS_3,
+		.csd = QT1050_CSD_3,
+	}, {
+		.nthr = QT1050_NTHR_4,
+		.pulse_scale = QT1050_PULSE_SCALE_4,
+		.di_aks = QT1050_DI_AKS_4,
+		.csd = QT1050_CSD_4,
+	}
+};
+
+static bool qt1050_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case QT1050_DET_STATUS:
+	case QT1050_KEY_STATUS:
+	case QT1050_KEY_SIGNAL_0_MSB:
+	case QT1050_KEY_SIGNAL_0_LSB:
+	case QT1050_KEY_SIGNAL_1_MSB:
+	case QT1050_KEY_SIGNAL_1_LSB:
+	case QT1050_KEY_SIGNAL_2_MSB:
+	case QT1050_KEY_SIGNAL_2_LSB:
+	case QT1050_KEY_SIGNAL_3_MSB:
+	case QT1050_KEY_SIGNAL_3_LSB:
+	case QT1050_KEY_SIGNAL_4_MSB:
+	case QT1050_KEY_SIGNAL_4_LSB:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_range qt1050_readable_ranges[] = {
+	regmap_reg_range(QT1050_CHIP_ID, QT1050_KEY_STATUS),
+	regmap_reg_range(QT1050_KEY_SIGNAL_0_MSB, QT1050_KEY_SIGNAL_1_LSB),
+	regmap_reg_range(QT1050_KEY_SIGNAL_2_MSB, QT1050_KEY_SIGNAL_4_LSB),
+	regmap_reg_range(QT1050_REF_DATA_0_MSB, QT1050_REF_DATA_1_LSB),
+	regmap_reg_range(QT1050_REF_DATA_2_MSB, QT1050_REF_DATA_4_LSB),
+	regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
+	regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
+	regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
+	regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
+	regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
+	regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
+	regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
+	regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
+};
+
+static const struct regmap_access_table qt1050_readable_table = {
+	.yes_ranges = qt1050_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(qt1050_readable_ranges),
+};
+
+static const struct regmap_range qt1050_writeable_ranges[] = {
+	regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
+	regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
+	regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
+	regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
+	regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
+	regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
+	regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
+	regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
+};
+
+static const struct regmap_access_table qt1050_writeable_table = {
+	.yes_ranges = qt1050_writeable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(qt1050_writeable_ranges),
+};
+
+static struct regmap_config qt1050_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = QT1050_RES_CAL,
+
+	.cache_type = REGCACHE_RBTREE,
+
+	.wr_table = &qt1050_writeable_table,
+	.rd_table = &qt1050_readable_table,
+	.volatile_reg = qt1050_volatile_reg,
+};
+
+static bool qt1050_identify(struct qt1050_priv *ts)
+{
+	unsigned int val;
+
+	/* Read Chip ID */
+	regmap_read(ts->regmap, QT1050_CHIP_ID, &val);
+	if (val != QT1050_CHIP_ID_VER) {
+		dev_err(&ts->client->dev, "ID %d not supported\n", val);
+		return false;
+	}
+
+	/* Read firmware version */
+	regmap_read(ts->regmap, QT1050_FW_VERSION, &val);
+	if (val < 0) {
+		dev_err(&ts->client->dev, "could not read the firmware version\n");
+		return false;
+	}
+
+	dev_info(&ts->client->dev, "AT42QT1050 firmware version %1d.%1d\n",
+		 val >> 4, val & 0xf);
+
+	return true;
+}
+
+static irqreturn_t qt1050_irq_threaded(int irq, void *dev_id)
+{
+	struct qt1050_priv *ts = dev_id;
+	struct input_dev *input = ts->input;
+	unsigned long new_keys, changed;
+	unsigned int val;
+	int i, j, err;
+
+	/* Read the detected status register, thus clearing interrupt */
+	err = regmap_read(ts->regmap, QT1050_DET_STATUS, &val);
+	if (err) {
+		dev_err(&ts->client->dev, "Fail to read detection status: %d\n",
+			err);
+		return IRQ_NONE;
+	}
+
+	/* Read which key changed, keys are not continuous */
+	err = regmap_read(ts->regmap, QT1050_KEY_STATUS, &val);
+	if (err) {
+		dev_err(&ts->client->dev,
+			"Fail to determine the key status: %d\n", err);
+		return IRQ_NONE;
+	}
+	new_keys = (val & 0x70) >> 2 | (val & 0x6) >> 1;
+	changed = ts->last_keys ^ new_keys;
+	/* report registered keys only */
+	changed &= ts->reg_keys;
+
+	for_each_set_bit(i, &changed, QT1050_MAX_KEYS) {
+		for (j = 0; j < ts->num_keys; j++) {
+			if (ts->keys[j].num == i)
+				input_report_key(input, ts->keys[j].keycode,
+						 test_bit(i, &new_keys));
+		}
+	}
+
+	ts->last_keys = new_keys;
+	input_sync(input);
+
+	return IRQ_HANDLED;
+}
+
+static const struct qt1050_key_regs *qt1050_get_key_regs(int key_num)
+{
+	return &qt1050_key_regs_data[key_num];
+}
+
+static int qt1050_set_key(struct regmap *map, int number, int on)
+{
+	const struct qt1050_key_regs *key_regs;
+
+	key_regs = qt1050_get_key_regs(number);
+
+	return regmap_update_bits(map, key_regs->di_aks, 0xfc,
+				  on ? BIT(4) : 0x00);
+}
+
+static int qt1050_apply_fw_data(struct qt1050_priv *ts)
+{
+	struct regmap *map = ts->regmap;
+	struct qt1050_key *button = ts->keys;
+	const struct qt1050_key_regs *key_regs;
+	int i, err;
+
+	/* Disable all keys and enable only the specified ones */
+	for (i = 0; i < QT1050_MAX_KEYS; i++) {
+		err = qt1050_set_key(map, i, 0);
+		if (err)
+			return err;
+	}
+
+	for (i = 0; i < ts->num_keys; i++, button++) {
+		/* keep KEY_RESERVED keys off */
+		if (button->keycode == KEY_RESERVED)
+			continue;
+
+		err = qt1050_set_key(map, button->num, 1);
+		if (err)
+			return err;
+
+		key_regs = qt1050_get_key_regs(button->num);
+
+		err = regmap_write(map, key_regs->pulse_scale,
+				   (button->samples << 4) | (button->scale));
+		if (err)
+			return err;
+		err = regmap_write(map, key_regs->csd, button->charge_delay);
+		if (err)
+			return err;
+		err = regmap_write(map, key_regs->nthr, button->thr_cnt);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int qt1050_parse_fw(struct qt1050_priv *ts)
+{
+	struct device *dev = &ts->client->dev;
+	struct qt1050_key *buttons;
+	struct fwnode_handle *child;
+	int nbuttons;
+
+	nbuttons = device_get_child_node_count(dev);
+	if (nbuttons == 0 || nbuttons > 5)
+		return -ENODEV;
+
+	buttons = devm_kcalloc(dev, nbuttons, sizeof(*buttons), GFP_KERNEL);
+	if (!buttons)
+		return -ENOMEM;
+
+	ts->num_keys = nbuttons;
+	ts->keys = buttons;
+
+	device_for_each_child_node(dev, child) {
+		/* required properties */
+		if (fwnode_property_read_u32(child, "linux,code",
+					     &buttons->keycode)) {
+			dev_err(dev, "Button without keycode\n");
+			fwnode_handle_put(child);
+			return -EINVAL;
+		}
+		if (buttons->keycode >= KEY_MAX) {
+			dev_err(dev, "wrong keycode 0x%x\n", buttons->keycode);
+			return -EINVAL;
+		}
+
+		if (fwnode_property_read_u32(child, "reg",
+					     &buttons->num)) {
+			dev_err(dev, "Button without pad number\n");
+			fwnode_handle_put(child);
+			return -EINVAL;
+		}
+		if (buttons->num < 0 || buttons->num > 4)
+			return -EINVAL;
+
+		ts->reg_keys |= BIT(buttons->num);
+
+		/* optional properties */
+		if (fwnode_property_read_u32(child,
+					     "microchip,pre-charge-time-ns",
+					     &buttons->charge_delay)) {
+			buttons->charge_delay = 0;
+		} else {
+			if (buttons->charge_delay % 2500 == 0)
+				buttons->charge_delay =
+					buttons->charge_delay / 2500;
+			else
+				buttons->charge_delay = 0;
+		}
+
+		if (fwnode_property_read_u32(child, "microchip,average-samples",
+					 &buttons->samples)) {
+			buttons->samples = 0;
+		} else {
+			if (is_power_of_2(buttons->samples))
+				buttons->samples = ilog2(buttons->samples);
+			else
+				buttons->samples = 0;
+		}
+
+		if (fwnode_property_read_u32(child, "microchip,average-scaling",
+					     &buttons->scale)) {
+			buttons->scale = 0;
+		} else {
+			if (is_power_of_2(buttons->scale))
+				buttons->scale = ilog2(buttons->scale);
+			else
+				buttons->scale = 0;
+
+		}
+
+		if (fwnode_property_read_u32(child, "microchip,threshold",
+					 &buttons->thr_cnt)) {
+			buttons->thr_cnt = 20;
+		} else {
+			if (buttons->thr_cnt > 255)
+				buttons->thr_cnt = 20;
+		}
+
+		buttons++;
+	}
+
+	return 0;
+}
+
+static int qt1050_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	struct qt1050_priv *ts;
+	struct input_dev *input;
+	struct device *dev = &client->dev;
+	struct regmap *map;
+	unsigned int status;
+	int i;
+	int err;
+
+	/* Check basic functionality */
+	err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
+	if (!err) {
+		dev_err(&client->dev, "%s adapter not supported\n",
+			dev_driver_string(&client->adapter->dev));
+		return -ENODEV;
+	}
+
+	if (!client->irq) {
+		dev_err(dev, "assign a irq line to this device\n");
+		return -EINVAL;
+	}
+
+	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+	input = devm_input_allocate_device(dev);
+	if (!ts || !input) {
+		dev_err(dev, "insufficient memory\n");
+		return -ENOMEM;
+	}
+
+	map = devm_regmap_init_i2c(client, &qt1050_regmap_config);
+	if (IS_ERR(map))
+		return PTR_ERR(map);
+
+	ts->client = client;
+	ts->input = input;
+	ts->regmap = map;
+
+	i2c_set_clientdata(client, ts);
+
+	/* Identify the qt1050 chip */
+	if (!qt1050_identify(ts))
+		return -ENODEV;
+
+	/* Get pdata */
+	err = qt1050_parse_fw(ts);
+	if (err) {
+		dev_err(dev, "Failed to parse firmware: %d\n", err);
+		return err;
+	}
+
+	input->name = "AT42QT1050 QTouch Sensor";
+	input->dev.parent = &client->dev;
+	input->id.bustype = BUS_I2C;
+
+	/* Add the keycode */
+	ts->keycodes = devm_kcalloc(dev, ts->num_keys, sizeof(*ts->keycodes),
+				    GFP_KERNEL);
+	if (!ts->keycodes)
+		return -ENOMEM;
+
+	input->keycode = ts->keycodes;
+	input->keycodesize = sizeof(*ts->keycodes);
+	input->keycodemax = ts->num_keys;
+
+	__set_bit(EV_KEY, input->evbit);
+	for (i = 0; i < ts->num_keys; i++) {
+		ts->keycodes[i] = ts->keys[i].keycode;
+		__set_bit(ts->keycodes[i], input->keybit);
+	}
+
+	/* Trigger re-calibration */
+	err = regmap_update_bits(ts->regmap, QT1050_RES_CAL, 0x7f,
+				 QT1050_RES_CAL_CALIBRATE);
+	if (err) {
+		dev_err(dev, "Trigger calibration failed: %d\n", err);
+		return err;
+	}
+	err = regmap_read_poll_timeout(ts->regmap, QT1050_DET_STATUS, status,
+				 status >> 7 == 1, 10000, 200000);
+	if (err) {
+		dev_err(dev, "Calibration failed: %d\n", err);
+		return err;
+	}
+
+	/* Soft reset to set defaults */
+	err = regmap_update_bits(ts->regmap, QT1050_RES_CAL,
+				 QT1050_RES_CAL_RESET, QT1050_RES_CAL_RESET);
+	if (err) {
+		dev_err(dev, "Trigger soft reset failed: %d\n", err);
+		return err;
+	}
+	msleep(QT1050_RESET_TIME);
+
+	/* Set pdata */
+	err = qt1050_apply_fw_data(ts);
+	if (err) {
+		dev_err(dev, "Failed to set firmware data: %d\n", err);
+		return err;
+	}
+
+	err = devm_request_threaded_irq(dev, client->irq, NULL,
+					qt1050_irq_threaded,
+					IRQF_TRIGGER_NONE | IRQF_ONESHOT,
+					"qt1050", ts);
+	if (err) {
+		dev_err(&client->dev, "Failed to request irq: %d\n", err);
+		return err;
+	}
+
+	/* clear #CHANGE line */
+	err = regmap_read(ts->regmap, QT1050_DET_STATUS, &status);
+	if (err) {
+		dev_err(dev, "Failed to clear #CHANGE line level: %d\n", err);
+		return err;
+	}
+
+	/* Register the input device */
+	err = input_register_device(ts->input);
+	if (err) {
+		dev_err(&client->dev, "Failed to register input device: %d\n",
+			err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused qt1050_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct qt1050_priv *ts = i2c_get_clientdata(client);
+
+	disable_irq(client->irq);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(client->irq);
+
+	return regmap_write(ts->regmap, QT1050_LPMODE, 0x00);
+}
+
+static int __maybe_unused qt1050_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct qt1050_priv *ts = i2c_get_clientdata(client);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(client->irq);
+
+	enable_irq(client->irq);
+
+	return regmap_write(ts->regmap, QT1050_LPMODE, 0x02);
+}
+
+static SIMPLE_DEV_PM_OPS(qt1050_pm_ops, qt1050_suspend, qt1050_resume);
+
+static const struct i2c_device_id qt1050_id[] = {
+	{ "qt1050", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, qt1050_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id qt1050_of_match[] = {
+	{ .compatible = "microchip,qt1050", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, qt1050_of_match);
+#endif
+
+static struct i2c_driver qt1050_driver = {
+	.driver	= {
+		.name	= "qt1050",
+		.of_match_table = of_match_ptr(qt1050_of_match),
+		.pm = &qt1050_pm_ops,
+	},
+	.probe		= qt1050_probe,
+	.id_table	= qt1050_id,
+};
+
+module_i2c_driver(qt1050_driver);
+
+MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de");
+MODULE_DESCRIPTION("Driver for AT42QT1050 QTouch sensor");
+MODULE_LICENSE("GPL");
-- 
2.19.1