| // 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", 0, }, |
| { } |
| }; |
| |
| 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"); |