Input: add driver for Atmel AT42QT2160 Sensor Chip
authorRaphael Derosso Pereira <raphaelpereira@gmail.com>
Tue, 22 Sep 2009 05:24:06 +0000 (22:24 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Wed, 23 Sep 2009 03:50:08 +0000 (20:50 -0700)
This version only supports individual cells (no slide support yet).
The code has been tested on proprietary development ARM board, but
should work fine on other machines.

Signed-off-by: Raphael Derosso Pereira <raphaelpereira@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
drivers/input/keyboard/Kconfig
drivers/input/keyboard/Makefile
drivers/input/keyboard/qt2160.c [new file with mode: 0644]

index 57055bc..ee98b1b 100644 (file)
@@ -114,6 +114,16 @@ config KEYBOARD_ATKBD_RDI_KEYCODES
          right-hand column will be interpreted as the key shown in the
          left-hand column.
 
+config QT2160
+       tristate "Atmel AT42QT2160 Touch Sensor Chip"
+       depends on I2C && EXPERIMENTAL
+       help
+         If you say yes here you get support for Atmel AT42QT2160 Touch
+         Sensor chip as a keyboard input.
+
+         This driver can also be built as a module. If so, the module
+         will be called qt2160.
+
 config KEYBOARD_BFIN
        tristate "Blackfin BF54x keypad support"
        depends on (BF54x && !BF544)
index 85ab894..babad5e 100644 (file)
@@ -28,6 +28,7 @@ obj-$(CONFIG_KEYBOARD_OMAP)           += omap-keypad.o
 obj-$(CONFIG_KEYBOARD_OPENCORES)       += opencores-kbd.o
 obj-$(CONFIG_KEYBOARD_PXA27x)          += pxa27x_keypad.o
 obj-$(CONFIG_KEYBOARD_PXA930_ROTARY)   += pxa930_rotary.o
+obj-$(CONFIG_KEYBOARD_QT2160)          += qt2160.o
 obj-$(CONFIG_KEYBOARD_SH_KEYSC)                += sh_keysc.o
 obj-$(CONFIG_KEYBOARD_SPITZ)           += spitzkbd.o
 obj-$(CONFIG_KEYBOARD_STOWAWAY)                += stowaway.o
diff --git a/drivers/input/keyboard/qt2160.c b/drivers/input/keyboard/qt2160.c
new file mode 100644 (file)
index 0000000..191cc51
--- /dev/null
@@ -0,0 +1,397 @@
+/*
+ *  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);
+
+       __cancel_delayed_work(&qt2160->dwork);
+       schedule_delayed_work(&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 __devinit 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 __devinit qt2160_write(struct i2c_client *client, u8 reg, u8 data)
+{
+       int error;
+
+       error = i2c_smbus_write_byte(client, reg);
+       if (error) {
+               dev_err(&client->dev,
+                       "couldn't send request. Returned %d\n", error);
+               return error;
+       }
+
+       error = i2c_smbus_write_byte(client, data);
+       if (error) {
+               dev_err(&client->dev,
+                       "couldn't write data. Returned %d\n", error);
+               return error;
+       }
+
+       return error;
+}
+
+
+static bool __devinit 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 __devinit 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);
+
+       i2c_set_clientdata(client, NULL);
+       return 0;
+}
+
+static 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         = __devexit_p(qt2160_remove),
+};
+
+static int __init qt2160_init(void)
+{
+       return i2c_add_driver(&qt2160_driver);
+}
+module_init(qt2160_init);
+
+static void __exit qt2160_cleanup(void)
+{
+       i2c_del_driver(&qt2160_driver);
+}
+module_exit(qt2160_cleanup);
+
+MODULE_AUTHOR("Raphael Derosso Pereira <raphaelpereira@gmail.com>");
+MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor");
+MODULE_LICENSE("GPL");