linux/drivers/input/keyboard/qt2160.c
Javier Martin 0e47e3dccf Input: qt2160 - add support for LEDs
Outputs x8..x0 of the qt2160 can have leds attached to it.
This patch handles those outputs using the generic LED
framework.

The PWM controls available in the chip are used to achieve
different levels of brightness.

Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2013-01-04 16:57:09 -08:00

514 lines
12 KiB
C

/*
* 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/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;
struct work_struct work;
char name[32];
int id;
enum led_brightness new_brightness;
};
#endif
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;
#ifdef CONFIG_LEDS_CLASS
struct qt2160_led leds[QT2160_NUM_LEDS_X];
struct mutex led_lock;
#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 void qt2160_led_work(struct work_struct *work)
{
struct qt2160_led *led = container_of(work, struct qt2160_led, work);
struct qt2160_data *qt2160 = led->qt2160;
struct i2c_client *client = qt2160->client;
int value = led->new_brightness;
u32 drive, pwmen;
mutex_lock(&qt2160->led_lock);
drive = qt2160_read(client, QT2160_CMD_DRIVE_X);
pwmen = qt2160_read(client, QT2160_CMD_PWMEN_X);
if (value != LED_OFF) {
drive |= (1 << led->id);
pwmen |= (1 << led->id);
} else {
drive &= ~(1 << led->id);
pwmen &= ~(1 << 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);
mutex_unlock(&qt2160->led_lock);
}
static void qt2160_led_set(struct led_classdev *cdev,
enum led_brightness value)
{
struct qt2160_led *led = container_of(cdev, struct qt2160_led, cdev);
led->new_brightness = value;
schedule_work(&led->work);
}
#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;
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;
}
#ifdef CONFIG_LEDS_CLASS
static int qt2160_register_leds(struct qt2160_data *qt2160)
{
struct i2c_client *client = qt2160->client;
int ret;
int i;
mutex_init(&qt2160->led_lock);
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 = qt2160_led_set;
led->cdev.brightness = LED_OFF;
led->id = i;
led->qt2160 = qt2160;
INIT_WORK(&led->work, qt2160_led_work);
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);
cancel_work_sync(&qt2160->leds[i].work);
}
}
#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);
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 = 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 int 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);
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");