// SPDX-License-Identifier: GPL-2.0-or-later
/*
* qt2160.c - Atmel AT42QT2160 Touch Sense Controller
*
* Copyright (C) 2009 Raphael Derosso Pereira <[email protected]>
*/
#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 <[email protected]>");
MODULE_DESCRIPTION("Driver for AT42QT2160 Touch Sensor");
MODULE_LICENSE("GPL");
Codebase Browser
linux