4 files changed, 688 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/input/microchip,qt1050.txt b/Documentation/devicetree/bindings/input/microchip,qt1050.txt
new file mode 100644
index 000000000000..80e75f96252b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/microchip,qt1050.txt
@@ -0,0 +1,78 @@
+Microchip AT42QT1050 Five-channel Touch Sensor IC
+
+The AT42QT1050 (QT1050) is a QTouchADC sensor device. The device can sense from
+one to five keys, dependent on mode. The QT1050 includes all signal processing
+functions necessary to provide stable sensing under a wide variety of changing
+conditions, and the outputs are fully debounced.
+
+The touchkey device node should be placed inside an I2C bus node.
+
+Required properties:
+- compatible: Must be "microchip,qt1050"
+- reg: The I2C address of the device
+- interrupts: The sink for the touchpad's IRQ output,
+  see ../interrupt-controller/interrupts.txt
+
+Optional properties:
+- wakeup-source: touch keys can be used as a wakeup source
+
+Each button (key) is represented as a sub-node:
+
+Each not specified key or key with linux,code set to KEY_RESERVED gets disabled
+in HW.
+
+Subnode properties:
+- linux,code: Keycode to emit.
+- reg: The key number. Valid values: 0, 1, 2, 3, 4.
+
+Optional subnode-properties:
+
+If a optional property is missing or has a invalid value the default value is
+taken.
+
+- microchip,pre-charge-time-ns:
+  Each touchpad need some time to precharge. The value depends on the mechanical
+  layout.
+  Valid value range: 0 - 637500; values must be a multiple of 2500;
+  default is 0.
+- microchip,average-samples:
+  Number of data samples which are averaged for each read.
+  Valid values: 1, 4, 16, 64, 256, 1024, 4096, 16384; default is 1.
+- microchip,average-scaling:
+  The scaling factor which is used to scale the average-samples.
+  Valid values: 1, 2, 4, 8, 16, 32, 64, 128; default is 1.
+- microchip,threshold:
+  Number of counts to register a touch detection.
+  Valid value range: 0 - 255; default is 20.
+
+Example:
+QT1050 with 3 non continuous keys, key2 and key4 are disabled.
+
+touchkeys@41 {
+        compatible = "microchip,qt1050";
+        reg = <0x41>;
+        interrupt-parent = <&gpio0>;
+        interrupts = <17 IRQ_TYPE_EDGE_FALLING>;
+
+        up@0 {
+                reg = <0>;
+                linux,code = <KEY_UP>;
+                microchip,average-samples = <64>;
+                microchip,average-scaling = <16>;
+                microchip,pre-charge-time-ns = <10000>;
+        };
+
+        right@1 {
+                reg = <1>;
+                linux,code = <KEY_RIGHT>;
+                microchip,average-samples = <64>;
+                microchip,average-scaling = <8>;
+        };
+
+        down@3 {
+                reg = <3>;
+                linux,code = <KEY_DOWN>;
+                microchip,average-samples = <256>;
+                microchip,average-scaling = <16>;
+        };
+};
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..403060d05c3b
--- /dev/null
+++ b/drivers/input/keyboard/qt1050.c
@@ -0,0 +1,598 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Microchip AT42QT1050 QTouch Sensor Controller
+ *
+ *  Copyright (C) 2019 Pengutronix, 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 {
+        u32 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[QT1050_MAX_KEYS];
+        unsigned short          keycodes[QT1050_MAX_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;
+        int err;
+
+        /* 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 */
+        err = regmap_read(ts->regmap, QT1050_FW_VERSION, &val);
+        if (err) {
+                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, 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)
+                input_report_key(input, ts->keys[i].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[0];
+        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 < QT1050_MAX_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 fwnode_handle *child;
+        int nbuttons;
+
+        nbuttons = device_get_child_node_count(dev);
+        if (nbuttons == 0 || nbuttons > QT1050_MAX_KEYS)
+                return -ENODEV;
+
+        device_for_each_child_node(dev, child) {
+                struct qt1050_key button;
+
+                /* Required properties */
+                if (fwnode_property_read_u32(child, "linux,code",
+                                             &button.keycode)) {
+                        dev_err(dev, "Button without keycode\n");
+                        goto err;
+                }
+                if (button.keycode >= KEY_MAX) {
+                        dev_err(dev, "Invalid keycode 0x%x\n",
+                                button.keycode);
+                        goto err;
+                }
+
+                if (fwnode_property_read_u32(child, "reg",
+                                             &button.num)) {
+                        dev_err(dev, "Button without pad number\n");
+                        goto err;
+                }
+                if (button.num < 0 || button.num > QT1050_MAX_KEYS - 1)
+                        goto err;
+
+                ts->reg_keys |= BIT(button.num);
+
+                /* Optional properties */
+                if (fwnode_property_read_u32(child,
+                                             "microchip,pre-charge-time-ns",
+                                             &button.charge_delay)) {
+                        button.charge_delay = 0;
+                } else {
+                        if (button.charge_delay % 2500 == 0)
+                                button.charge_delay =
+                                        button.charge_delay / 2500;
+                        else
+                                button.charge_delay = 0;
+                }
+
+                if (fwnode_property_read_u32(child, "microchip,average-samples",
+                                         &button.samples)) {
+                        button.samples = 0;
+                } else {
+                        if (is_power_of_2(button.samples))
+                                button.samples = ilog2(button.samples);
+                        else
+                                button.samples = 0;
+                }
+
+                if (fwnode_property_read_u32(child, "microchip,average-scaling",
+                                             &button.scale)) {
+                        button.scale = 0;
+                } else {
+                        if (is_power_of_2(button.scale))
+                                button.scale = ilog2(button.scale);
+                        else
+                                button.scale = 0;
+
+                }
+
+                if (fwnode_property_read_u32(child, "microchip,threshold",
+                                         &button.thr_cnt)) {
+                        button.thr_cnt = 20;
+                } else {
+                        if (button.thr_cnt > 255)
+                                button.thr_cnt = 20;
+                }
+
+                ts->keys[button.num] = button;
+        }
+
+        return 0;
+
+err:
+        fwnode_handle_put(child);
+        return -EINVAL;
+}
+
+static int qt1050_probe(struct i2c_client *client)
+{
+        struct qt1050_priv *ts;
+        struct input_dev *input;
+        struct device *dev = &client->dev;
+        struct regmap *map;
+        unsigned int status, 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);
+        if (!ts)
+                return -ENOMEM;
+
+        input = devm_input_allocate_device(dev);
+        if (!input)
+                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 */
+        input->keycode = ts->keycodes;
+        input->keycodesize = sizeof(ts->keycodes[0]);
+        input->keycodemax = QT1050_MAX_KEYS;
+
+        __set_bit(EV_KEY, input->evbit);
+        for (i = 0; i < QT1050_MAX_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_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);
+
+        /*
+         * Set measurement interval to 1s (125 x 8ms) if wakeup is allowed
+         * else turn off. The 1s interval seems to be a good compromise between
+         * low power and response time.
+         */
+        return regmap_write(ts->regmap, QT1050_LPMODE,
+                            device_may_wakeup(dev) ? 125 : 0);
+}
+
+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);
+
+        enable_irq(client->irq);
+
+        /* Set measurement interval back to 16ms (2 x 8ms) */
+        return regmap_write(ts->regmap, QT1050_LPMODE, 2);
+}
+
+static SIMPLE_DEV_PM_OPS(qt1050_pm_ops, qt1050_suspend, qt1050_resume);
+
+static const struct of_device_id __maybe_unused qt1050_of_match[] = {
+        { .compatible = "microchip,qt1050", },
+        { },
+};
+MODULE_DEVICE_TABLE(of, qt1050_of_match);
+
+static struct i2c_driver qt1050_driver = {
+        .driver = {
+                .name = "qt1050",
+                .of_match_table = of_match_ptr(qt1050_of_match),
+                .pm = &qt1050_pm_ops,
+        },
+        .probe_new = qt1050_probe,
+};
+
+module_i2c_driver(qt1050_driver);
+
+MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de");
+MODULE_DESCRIPTION("Driver for AT42QT1050 QTouch sensor");
+MODULE_LICENSE("GPL v2");