|  | // 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	2000 /* msec - 2 sec */ | 
|  |  | 
|  | 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; | 
|  | 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 void qt2160_get_key_matrix(struct input_dev *input) | 
|  | { | 
|  | struct qt2160_data *qt2160 = input_get_drvdata(input); | 
|  | struct i2c_client *client = qt2160->client; | 
|  | 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; | 
|  | } | 
|  |  | 
|  | 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); | 
|  | } | 
|  |  | 
|  | static irqreturn_t qt2160_irq(int irq, void *data) | 
|  | { | 
|  | struct input_dev *input = data; | 
|  |  | 
|  | qt2160_get_key_matrix(input); | 
|  |  | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | 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 error; | 
|  | 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; | 
|  |  | 
|  | error = devm_led_classdev_register(&client->dev, &led->cdev); | 
|  | if (error) | 
|  | return error; | 
|  | } | 
|  |  | 
|  | /* 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; | 
|  | } | 
|  |  | 
|  | #else | 
|  |  | 
|  | static inline int qt2160_register_leds(struct qt2160_data *qt2160) | 
|  | { | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | #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) | 
|  | { | 
|  | struct qt2160_data *qt2160; | 
|  | struct input_dev *input; | 
|  | int i; | 
|  | int error; | 
|  |  | 
|  | if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) { | 
|  | 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 = devm_kzalloc(&client->dev, sizeof(*qt2160), GFP_KERNEL); | 
|  | if (!qt2160) | 
|  | return -ENOMEM; | 
|  |  | 
|  | input = devm_input_allocate_device(&client->dev); | 
|  | if (!input) | 
|  | return -ENOMEM; | 
|  |  | 
|  | qt2160->client = client; | 
|  | qt2160->input = input; | 
|  |  | 
|  | 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); | 
|  |  | 
|  | input_set_drvdata(input, qt2160); | 
|  |  | 
|  | /* Calibrate device */ | 
|  | error = qt2160_write(client, QT2160_CMD_CALIBRATE, 1); | 
|  | if (error) { | 
|  | dev_err(&client->dev, "failed to calibrate device\n"); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | if (client->irq) { | 
|  | error = devm_request_threaded_irq(&client->dev, client->irq, | 
|  | NULL, qt2160_irq, | 
|  | IRQF_ONESHOT, | 
|  | "qt2160", input); | 
|  | if (error) { | 
|  | dev_err(&client->dev, | 
|  | "failed to allocate irq %d\n", client->irq); | 
|  | return error; | 
|  | } | 
|  | } else { | 
|  | error = input_setup_polling(input, qt2160_get_key_matrix); | 
|  | if (error) { | 
|  | dev_err(&client->dev, "Failed to setup polling\n"); | 
|  | return error; | 
|  | } | 
|  | input_set_poll_interval(input, QT2160_CYCLE_INTERVAL); | 
|  | } | 
|  |  | 
|  | error = qt2160_register_leds(qt2160); | 
|  | if (error) { | 
|  | dev_err(&client->dev, "Failed to register leds\n"); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | error = input_register_device(qt2160->input); | 
|  | if (error) { | 
|  | dev_err(&client->dev, | 
|  | "Failed to register input device\n"); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct i2c_device_id qt2160_idtable[] = { | 
|  | { "qt2160" }, | 
|  | { } | 
|  | }; | 
|  |  | 
|  | MODULE_DEVICE_TABLE(i2c, qt2160_idtable); | 
|  |  | 
|  | static struct i2c_driver qt2160_driver = { | 
|  | .driver = { | 
|  | .name	= "qt2160", | 
|  | }, | 
|  |  | 
|  | .id_table	= qt2160_idtable, | 
|  | .probe		= qt2160_probe, | 
|  | }; | 
|  |  | 
|  | module_i2c_driver(qt2160_driver); | 
|  |  | 
|  | MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>"); | 
|  | MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor"); | 
|  | MODULE_LICENSE("GPL"); |