| /* |
| * qt2160.c - Atmel AT42QT2160 Touch Sense Controller |
| * |
| * Copyright (C) 2009 Raphael Derosso Pereira <raphaelpereira@gmail.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/init.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_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, |
| }; |
| |
| struct qt2160_data { |
| struct i2c_client *client; |
| struct input_dev *input; |
| struct delayed_work dwork; |
| spinlock_t lock; /* Protects canceling/rescheduling of dwork */ |
| unsigned short keycodes[ARRAY_SIZE(qt2160_key2code)]; |
| u16 key_matrix; |
| }; |
| |
| 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; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&qt2160->lock, flags); |
| |
| mod_delayed_work(system_wq, &qt2160->dwork, 0); |
| |
| spin_unlock_irqrestore(&qt2160->lock, flags); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static void qt2160_schedule_read(struct qt2160_data *qt2160) |
| { |
| spin_lock_irq(&qt2160->lock); |
| schedule_delayed_work(&qt2160->dwork, QT2160_CYCLE_INTERVAL); |
| spin_unlock_irq(&qt2160->lock); |
| } |
| |
| 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; |
| } |
| |
| |
| 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); |
| spin_lock_init(&qt2160->lock); |
| |
| 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 = input_register_device(qt2160->input); |
| if (error) { |
| dev_err(&client->dev, |
| "Failed to register input device\n"); |
| goto err_free_irq; |
| } |
| |
| i2c_set_clientdata(client, qt2160); |
| qt2160_schedule_read(qt2160); |
| |
| return 0; |
| |
| err_free_irq: |
| if (client->irq) |
| free_irq(client->irq, qt2160); |
| err_free_mem: |
| input_free_device(input); |
| kfree(qt2160); |
| return error; |
| } |
| |
| static int __devexit qt2160_remove(struct i2c_client *client) |
| { |
| struct qt2160_data *qt2160 = i2c_get_clientdata(client); |
| |
| /* 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); |
| |
| 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", |
| .owner = THIS_MODULE, |
| }, |
| |
| .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"); |