tm2-touchkey.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* TM2 touchkey device driver
*
* Copyright 2005 Phil Blundell
* Copyright 2016 Samsung Electronics Co., Ltd.
*
* Author: Beomho Seo <beomho.seo@samsung.com>
* Author: Jaechul Lee <jcsing.lee@samsung.com>
*/
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pm.h>
#include <linux/regulator/consumer.h>
#define TM2_TOUCHKEY_DEV_NAME "tm2-touchkey"
#define ARIES_TOUCHKEY_CMD_LED_ON 0x1
#define ARIES_TOUCHKEY_CMD_LED_OFF 0x2
#define TM2_TOUCHKEY_CMD_LED_ON 0x10
#define TM2_TOUCHKEY_CMD_LED_OFF 0x20
#define TM2_TOUCHKEY_BIT_PRESS_EV BIT(3)
#define TM2_TOUCHKEY_BIT_KEYCODE GENMASK(2, 0)
#define TM2_TOUCHKEY_LED_VOLTAGE_MIN 2500000
#define TM2_TOUCHKEY_LED_VOLTAGE_MAX 3300000
struct touchkey_variant {
u8 keycode_reg;
u8 base_reg;
u8 cmd_led_on;
u8 cmd_led_off;
bool no_reg;
bool fixed_regulator;
};
struct tm2_touchkey_data {
struct i2c_client *client;
struct input_dev *input_dev;
struct led_classdev led_dev;
struct regulator *vdd;
struct regulator_bulk_data regulators[3];
const struct touchkey_variant *variant;
u32 keycodes[4];
int num_keycodes;
};
static const struct touchkey_variant tm2_touchkey_variant = {
.keycode_reg = 0x03,
.base_reg = 0x00,
.cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
.cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
};
static const struct touchkey_variant midas_touchkey_variant = {
.keycode_reg = 0x00,
.base_reg = 0x00,
.cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
.cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
};
static struct touchkey_variant aries_touchkey_variant = {
.no_reg = true,
.fixed_regulator = true,
.cmd_led_on = ARIES_TOUCHKEY_CMD_LED_ON,
.cmd_led_off = ARIES_TOUCHKEY_CMD_LED_OFF,
};
static const struct touchkey_variant tc360_touchkey_variant = {
.keycode_reg = 0x00,
.base_reg = 0x00,
.fixed_regulator = true,
.cmd_led_on = TM2_TOUCHKEY_CMD_LED_ON,
.cmd_led_off = TM2_TOUCHKEY_CMD_LED_OFF,
};
static int tm2_touchkey_led_brightness_set(struct led_classdev *led_dev,
enum led_brightness brightness)
{
struct tm2_touchkey_data *touchkey =
container_of(led_dev, struct tm2_touchkey_data, led_dev);
u32 volt;
u8 data;
if (brightness == LED_OFF) {
volt = TM2_TOUCHKEY_LED_VOLTAGE_MIN;
data = touchkey->variant->cmd_led_off;
} else {
volt = TM2_TOUCHKEY_LED_VOLTAGE_MAX;
data = touchkey->variant->cmd_led_on;
}
if (!touchkey->variant->fixed_regulator)
regulator_set_voltage(touchkey->vdd, volt, volt);
return touchkey->variant->no_reg ?
i2c_smbus_write_byte(touchkey->client, data) :
i2c_smbus_write_byte_data(touchkey->client,
touchkey->variant->base_reg, data);
}
static int tm2_touchkey_power_enable(struct tm2_touchkey_data *touchkey)
{
int error;
error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
touchkey->regulators);
if (error)
return error;
/* waiting for device initialization, at least 150ms */
msleep(150);
return 0;
}
static void tm2_touchkey_power_disable(void *data)
{
struct tm2_touchkey_data *touchkey = data;
regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
touchkey->regulators);
}
static irqreturn_t tm2_touchkey_irq_handler(int irq, void *devid)
{
struct tm2_touchkey_data *touchkey = devid;
int data;
int index;
int i;
if (touchkey->variant->no_reg)
data = i2c_smbus_read_byte(touchkey->client);
else
data = i2c_smbus_read_byte_data(touchkey->client,
touchkey->variant->keycode_reg);
if (data < 0) {
dev_err(&touchkey->client->dev,
"failed to read i2c data: %d\n", data);
goto out;
}
index = (data & TM2_TOUCHKEY_BIT_KEYCODE) - 1;
if (index < 0 || index >= touchkey->num_keycodes) {
dev_warn(&touchkey->client->dev,
"invalid keycode index %d\n", index);
goto out;
}
if (data & TM2_TOUCHKEY_BIT_PRESS_EV) {
for (i = 0; i < touchkey->num_keycodes; i++)
input_report_key(touchkey->input_dev,
touchkey->keycodes[i], 0);
} else {
input_report_key(touchkey->input_dev,
touchkey->keycodes[index], 1);
}
input_sync(touchkey->input_dev);
out:
if (touchkey->variant->fixed_regulator &&
data & TM2_TOUCHKEY_BIT_PRESS_EV) {
/* touch turns backlight on, so make sure we're in sync */
if (touchkey->led_dev.brightness == LED_OFF)
tm2_touchkey_led_brightness_set(&touchkey->led_dev,
LED_OFF);
}
return IRQ_HANDLED;
}
static int tm2_touchkey_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device_node *np = client->dev.of_node;
struct tm2_touchkey_data *touchkey;
int error;
int i;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) {
dev_err(&client->dev, "incompatible I2C adapter\n");
return -EIO;
}
touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
if (!touchkey)
return -ENOMEM;
touchkey->client = client;
i2c_set_clientdata(client, touchkey);
touchkey->variant = of_device_get_match_data(&client->dev);
touchkey->regulators[0].supply = "vcc";
touchkey->regulators[1].supply = "vdd";
touchkey->regulators[2].supply = "vddio";
error = devm_regulator_bulk_get(&client->dev,
ARRAY_SIZE(touchkey->regulators),
touchkey->regulators);
if (error) {
dev_err(&client->dev, "failed to get regulators: %d\n", error);
return error;
}
/* Save VDD for easy access */
touchkey->vdd = touchkey->regulators[1].consumer;
touchkey->num_keycodes = of_property_read_variable_u32_array(np,
"linux,keycodes", touchkey->keycodes, 0,
ARRAY_SIZE(touchkey->keycodes));
if (touchkey->num_keycodes <= 0) {
/* default keycodes */
touchkey->keycodes[0] = KEY_PHONE;
touchkey->keycodes[1] = KEY_BACK;
touchkey->num_keycodes = 2;
}
error = tm2_touchkey_power_enable(touchkey);
if (error) {
dev_err(&client->dev, "failed to power up device: %d\n", error);
return error;
}
error = devm_add_action_or_reset(&client->dev,
tm2_touchkey_power_disable, touchkey);
if (error) {
dev_err(&client->dev,
"failed to install poweroff handler: %d\n", error);
return error;
}
/* input device */
touchkey->input_dev = devm_input_allocate_device(&client->dev);
if (!touchkey->input_dev) {
dev_err(&client->dev, "failed to allocate input device\n");
return -ENOMEM;
}
touchkey->input_dev->name = TM2_TOUCHKEY_DEV_NAME;
touchkey->input_dev->id.bustype = BUS_I2C;
for (i = 0; i < touchkey->num_keycodes; i++)
input_set_capability(touchkey->input_dev, EV_KEY,
touchkey->keycodes[i]);
error = input_register_device(touchkey->input_dev);
if (error) {
dev_err(&client->dev,
"failed to register input device: %d\n", error);
return error;
}
error = devm_request_threaded_irq(&client->dev, client->irq,
NULL, tm2_touchkey_irq_handler,
IRQF_ONESHOT,
TM2_TOUCHKEY_DEV_NAME, touchkey);
if (error) {
dev_err(&client->dev,
"failed to request threaded irq: %d\n", error);
return error;
}
/* led device */
touchkey->led_dev.name = TM2_TOUCHKEY_DEV_NAME;
touchkey->led_dev.brightness = LED_ON;
touchkey->led_dev.max_brightness = LED_ON;
touchkey->led_dev.brightness_set_blocking =
tm2_touchkey_led_brightness_set;
error = devm_led_classdev_register(&client->dev, &touchkey->led_dev);
if (error) {
dev_err(&client->dev,
"failed to register touchkey led: %d\n", error);
return error;
}
if (touchkey->variant->fixed_regulator)
tm2_touchkey_led_brightness_set(&touchkey->led_dev, LED_ON);
return 0;
}
static int __maybe_unused tm2_touchkey_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
disable_irq(client->irq);
tm2_touchkey_power_disable(touchkey);
return 0;
}
static int __maybe_unused tm2_touchkey_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct tm2_touchkey_data *touchkey = i2c_get_clientdata(client);
int ret;
enable_irq(client->irq);
ret = tm2_touchkey_power_enable(touchkey);
if (ret)
dev_err(dev, "failed to enable power: %d\n", ret);
return ret;
}
static SIMPLE_DEV_PM_OPS(tm2_touchkey_pm_ops,
tm2_touchkey_suspend, tm2_touchkey_resume);
static const struct i2c_device_id tm2_touchkey_id_table[] = {
{ TM2_TOUCHKEY_DEV_NAME, 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, tm2_touchkey_id_table);
static const struct of_device_id tm2_touchkey_of_match[] = {
{
.compatible = "cypress,tm2-touchkey",
.data = &tm2_touchkey_variant,
}, {
.compatible = "cypress,midas-touchkey",
.data = &midas_touchkey_variant,
}, {
.compatible = "cypress,aries-touchkey",
.data = &aries_touchkey_variant,
}, {
.compatible = "coreriver,tc360-touchkey",
.data = &tc360_touchkey_variant,
},
{ },
};
MODULE_DEVICE_TABLE(of, tm2_touchkey_of_match);
static struct i2c_driver tm2_touchkey_driver = {
.driver = {
.name = TM2_TOUCHKEY_DEV_NAME,
.pm = &tm2_touchkey_pm_ops,
.of_match_table = of_match_ptr(tm2_touchkey_of_match),
},
.probe = tm2_touchkey_probe,
.id_table = tm2_touchkey_id_table,
};
module_i2c_driver(tm2_touchkey_driver);
MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
MODULE_AUTHOR("Jaechul Lee <jcsing.lee@samsung.com>");
MODULE_DESCRIPTION("Samsung touchkey driver");
MODULE_LICENSE("GPL v2");