1 files changed, 472 insertions, 0 deletions
diff --git a/drivers/input/keyboard/qt2160.c b/drivers/input/keyboard/qt2160.c
new file mode 100644
index 000000000..382b15192
--- /dev/null
+++ b/drivers/input/keyboard/qt2160.c
@@ -0,0 +1,472 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  qt2160.c - Atmel AT42QT2160 Touch Sense Controller
+ *
+ *  Copyright (C) 2009 Raphael Derosso Pereira <raphaelpereira@gmail.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+
+#define QT2160_VALID_CHIPID  0x11
+
+#define QT2160_CMD_CHIPID     0
+#define QT2160_CMD_CODEVER    1
+#define QT2160_CMD_GSTAT      2
+#define QT2160_CMD_KEYS3      3
+#define QT2160_CMD_KEYS4      4
+#define QT2160_CMD_SLIDE      5
+#define QT2160_CMD_GPIOS      6
+#define QT2160_CMD_SUBVER     7
+#define QT2160_CMD_CALIBRATE  10
+#define QT2160_CMD_DRIVE_X    70
+#define QT2160_CMD_PWMEN_X    74
+#define QT2160_CMD_PWM_DUTY   76
+
+#define QT2160_NUM_LEDS_X	8
+
+#define QT2160_CYCLE_INTERVAL	(2*HZ)
+
+static unsigned char qt2160_key2code[] = {
+	KEY_0, KEY_1, KEY_2, KEY_3,
+	KEY_4, KEY_5, KEY_6, KEY_7,
+	KEY_8, KEY_9, KEY_A, KEY_B,
+	KEY_C, KEY_D, KEY_E, KEY_F,
+};
+
+#ifdef CONFIG_LEDS_CLASS
+struct qt2160_led {
+	struct qt2160_data *qt2160;
+	struct led_classdev cdev;
+	char name[32];
+	int id;
+	enum led_brightness brightness;
+};
+#endif
+
+struct qt2160_data {
+	struct i2c_client *client;
+	struct input_dev *input;
+	struct delayed_work dwork;
+	unsigned short keycodes[ARRAY_SIZE(qt2160_key2code)];
+	u16 key_matrix;
+#ifdef CONFIG_LEDS_CLASS
+	struct qt2160_led leds[QT2160_NUM_LEDS_X];
+#endif
+};
+
+static int qt2160_read(struct i2c_client *client, u8 reg);
+static int qt2160_write(struct i2c_client *client, u8 reg, u8 data);
+
+#ifdef CONFIG_LEDS_CLASS
+
+static int qt2160_led_set(struct led_classdev *cdev,
+			  enum led_brightness value)
+{
+	struct qt2160_led *led = container_of(cdev, struct qt2160_led, cdev);
+	struct qt2160_data *qt2160 = led->qt2160;
+	struct i2c_client *client = qt2160->client;
+	u32 drive, pwmen;
+
+	if (value != led->brightness) {
+		drive = qt2160_read(client, QT2160_CMD_DRIVE_X);
+		pwmen = qt2160_read(client, QT2160_CMD_PWMEN_X);
+		if (value != LED_OFF) {
+			drive |= BIT(led->id);
+			pwmen |= BIT(led->id);
+
+		} else {
+			drive &= ~BIT(led->id);
+			pwmen &= ~BIT(led->id);
+		}
+		qt2160_write(client, QT2160_CMD_DRIVE_X, drive);
+		qt2160_write(client, QT2160_CMD_PWMEN_X, pwmen);
+
+		/*
+		 * Changing this register will change the brightness
+		 * of every LED in the qt2160. It's a HW limitation.
+		 */
+		if (value != LED_OFF)
+			qt2160_write(client, QT2160_CMD_PWM_DUTY, value);
+
+		led->brightness = value;
+	}
+
+	return 0;
+}
+
+#endif /* CONFIG_LEDS_CLASS */
+
+static int qt2160_read_block(struct i2c_client *client,
+			     u8 inireg, u8 *buffer, unsigned int count)
+{
+	int error, idx = 0;
+
+	/*
+	 * Can't use SMBus block data read. Check for I2C functionality to speed
+	 * things up whenever possible. Otherwise we will be forced to read
+	 * sequentially.
+	 */
+	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C))	{
+
+		error = i2c_smbus_write_byte(client, inireg + idx);
+		if (error) {
+			dev_err(&client->dev,
+				"couldn't send request. Returned %d\n", error);
+			return error;
+		}
+
+		error = i2c_master_recv(client, buffer, count);
+		if (error != count) {
+			dev_err(&client->dev,
+				"couldn't read registers. Returned %d bytes\n", error);
+			return error;
+		}
+	} else {
+
+		while (count--) {
+			int data;
+
+			error = i2c_smbus_write_byte(client, inireg + idx);
+			if (error) {
+				dev_err(&client->dev,
+					"couldn't send request. Returned %d\n", error);
+				return error;
+			}
+
+			data = i2c_smbus_read_byte(client);
+			if (data < 0) {
+				dev_err(&client->dev,
+					"couldn't read register. Returned %d\n", data);
+				return data;
+			}
+
+			buffer[idx++] = data;
+		}
+	}
+
+	return 0;
+}
+
+static int qt2160_get_key_matrix(struct qt2160_data *qt2160)
+{
+	struct i2c_client *client = qt2160->client;
+	struct input_dev *input = qt2160->input;
+	u8 regs[6];
+	u16 old_matrix, new_matrix;
+	int ret, i, mask;
+
+	dev_dbg(&client->dev, "requesting keys...\n");
+
+	/*
+	 * Read all registers from General Status Register
+	 * to GPIOs register
+	 */
+	ret = qt2160_read_block(client, QT2160_CMD_GSTAT, regs, 6);
+	if (ret) {
+		dev_err(&client->dev,
+			"could not perform chip read.\n");
+		return ret;
+	}
+
+	old_matrix = qt2160->key_matrix;
+	qt2160->key_matrix = new_matrix = (regs[2] << 8) | regs[1];
+
+	mask = 0x01;
+	for (i = 0; i < 16; ++i, mask <<= 1) {
+		int keyval = new_matrix & mask;
+
+		if ((old_matrix & mask) != keyval) {
+			input_report_key(input, qt2160->keycodes[i], keyval);
+			dev_dbg(&client->dev, "key %d %s\n",
+				i, keyval ? "pressed" : "released");
+		}
+	}
+
+	input_sync(input);
+
+	return 0;
+}
+
+static irqreturn_t qt2160_irq(int irq, void *_qt2160)
+{
+	struct qt2160_data *qt2160 = _qt2160;
+
+	mod_delayed_work(system_wq, &qt2160->dwork, 0);
+
+	return IRQ_HANDLED;
+}
+
+static void qt2160_schedule_read(struct qt2160_data *qt2160)
+{
+	schedule_delayed_work(&qt2160->dwork, QT2160_CYCLE_INTERVAL);
+}
+
+static void qt2160_worker(struct work_struct *work)
+{
+	struct qt2160_data *qt2160 =
+		container_of(work, struct qt2160_data, dwork.work);
+
+	dev_dbg(&qt2160->client->dev, "worker\n");
+
+	qt2160_get_key_matrix(qt2160);
+
+	/* Avoid device lock up by checking every so often */
+	qt2160_schedule_read(qt2160);
+}
+
+static int qt2160_read(struct i2c_client *client, u8 reg)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte(client, reg);
+	if (ret) {
+		dev_err(&client->dev,
+			"couldn't send request. Returned %d\n", ret);
+		return ret;
+	}
+
+	ret = i2c_smbus_read_byte(client);
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"couldn't read register. Returned %d\n", ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+static int qt2160_write(struct i2c_client *client, u8 reg, u8 data)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client, reg, data);
+	if (ret < 0)
+		dev_err(&client->dev,
+			"couldn't write data. Returned %d\n", ret);
+
+	return ret;
+}
+
+#ifdef CONFIG_LEDS_CLASS
+
+static int qt2160_register_leds(struct qt2160_data *qt2160)
+{
+	struct i2c_client *client = qt2160->client;
+	int ret;
+	int i;
+
+	for (i = 0; i < QT2160_NUM_LEDS_X; i++) {
+		struct qt2160_led *led = &qt2160->leds[i];
+
+		snprintf(led->name, sizeof(led->name), "qt2160:x%d", i);
+		led->cdev.name = led->name;
+		led->cdev.brightness_set_blocking = qt2160_led_set;
+		led->cdev.brightness = LED_OFF;
+		led->id = i;
+		led->qt2160 = qt2160;
+
+		ret = led_classdev_register(&client->dev, &led->cdev);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Tur off LEDs */
+	qt2160_write(client, QT2160_CMD_DRIVE_X, 0);
+	qt2160_write(client, QT2160_CMD_PWMEN_X, 0);
+	qt2160_write(client, QT2160_CMD_PWM_DUTY, 0);
+
+	return 0;
+}
+
+static void qt2160_unregister_leds(struct qt2160_data *qt2160)
+{
+	int i;
+
+	for (i = 0; i < QT2160_NUM_LEDS_X; i++)
+		led_classdev_unregister(&qt2160->leds[i].cdev);
+}
+
+#else
+
+static inline int qt2160_register_leds(struct qt2160_data *qt2160)
+{
+	return 0;
+}
+
+static inline void qt2160_unregister_leds(struct qt2160_data *qt2160)
+{
+}
+
+#endif
+
+static bool qt2160_identify(struct i2c_client *client)
+{
+	int id, ver, rev;
+
+	/* Read Chid ID to check if chip is valid */
+	id = qt2160_read(client, QT2160_CMD_CHIPID);
+	if (id != QT2160_VALID_CHIPID) {
+		dev_err(&client->dev, "ID %d not supported\n", id);
+		return false;
+	}
+
+	/* Read chip firmware version */
+	ver = qt2160_read(client, QT2160_CMD_CODEVER);
+	if (ver < 0) {
+		dev_err(&client->dev, "could not get firmware version\n");
+		return false;
+	}
+
+	/* Read chip firmware revision */
+	rev = qt2160_read(client, QT2160_CMD_SUBVER);
+	if (rev < 0) {
+		dev_err(&client->dev, "could not get firmware revision\n");
+		return false;
+	}
+
+	dev_info(&client->dev, "AT42QT2160 firmware version %d.%d.%d\n",
+			ver >> 4, ver & 0xf, rev);
+
+	return true;
+}
+
+static int qt2160_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct qt2160_data *qt2160;
+	struct input_dev *input;
+	int i;
+	int error;
+
+	/* Check functionality */
+	error = i2c_check_functionality(client->adapter,
+			I2C_FUNC_SMBUS_BYTE);
+	if (!error) {
+		dev_err(&client->dev, "%s adapter not supported\n",
+				dev_driver_string(&client->adapter->dev));
+		return -ENODEV;
+	}
+
+	if (!qt2160_identify(client))
+		return -ENODEV;
+
+	/* Chip is valid and active. Allocate structure */
+	qt2160 = kzalloc(sizeof(struct qt2160_data), GFP_KERNEL);
+	input = input_allocate_device();
+	if (!qt2160 || !input) {
+		dev_err(&client->dev, "insufficient memory\n");
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	qt2160->client = client;
+	qt2160->input = input;
+	INIT_DELAYED_WORK(&qt2160->dwork, qt2160_worker);
+
+	input->name = "AT42QT2160 Touch Sense Keyboard";
+	input->id.bustype = BUS_I2C;
+
+	input->keycode = qt2160->keycodes;
+	input->keycodesize = sizeof(qt2160->keycodes[0]);
+	input->keycodemax = ARRAY_SIZE(qt2160_key2code);
+
+	__set_bit(EV_KEY, input->evbit);
+	__clear_bit(EV_REP, input->evbit);
+	for (i = 0; i < ARRAY_SIZE(qt2160_key2code); i++) {
+		qt2160->keycodes[i] = qt2160_key2code[i];
+		__set_bit(qt2160_key2code[i], input->keybit);
+	}
+	__clear_bit(KEY_RESERVED, input->keybit);
+
+	/* Calibrate device */
+	error = qt2160_write(client, QT2160_CMD_CALIBRATE, 1);
+	if (error) {
+		dev_err(&client->dev, "failed to calibrate device\n");
+		goto err_free_mem;
+	}
+
+	if (client->irq) {
+		error = request_irq(client->irq, qt2160_irq,
+				    IRQF_TRIGGER_FALLING, "qt2160", qt2160);
+		if (error) {
+			dev_err(&client->dev,
+				"failed to allocate irq %d\n", client->irq);
+			goto err_free_mem;
+		}
+	}
+
+	error = qt2160_register_leds(qt2160);
+	if (error) {
+		dev_err(&client->dev, "Failed to register leds\n");
+		goto err_free_irq;
+	}
+
+	error = input_register_device(qt2160->input);
+	if (error) {
+		dev_err(&client->dev,
+			"Failed to register input device\n");
+		goto err_unregister_leds;
+	}
+
+	i2c_set_clientdata(client, qt2160);
+	qt2160_schedule_read(qt2160);
+
+	return 0;
+
+err_unregister_leds:
+	qt2160_unregister_leds(qt2160);
+err_free_irq:
+	if (client->irq)
+		free_irq(client->irq, qt2160);
+err_free_mem:
+	input_free_device(input);
+	kfree(qt2160);
+	return error;
+}
+
+static void qt2160_remove(struct i2c_client *client)
+{
+	struct qt2160_data *qt2160 = i2c_get_clientdata(client);
+
+	qt2160_unregister_leds(qt2160);
+
+	/* Release IRQ so no queue will be scheduled */
+	if (client->irq)
+		free_irq(client->irq, qt2160);
+
+	cancel_delayed_work_sync(&qt2160->dwork);
+
+	input_unregister_device(qt2160->input);
+	kfree(qt2160);
+}
+
+static const struct i2c_device_id qt2160_idtable[] = {
+	{ "qt2160", 0, },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, qt2160_idtable);
+
+static struct i2c_driver qt2160_driver = {
+	.driver = {
+		.name	= "qt2160",
+	},
+
+	.id_table	= qt2160_idtable,
+	.probe		= qt2160_probe,
+	.remove		= qt2160_remove,
+};
+
+module_i2c_driver(qt2160_driver);
+
+MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>");
+MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor");
+MODULE_LICENSE("GPL");