// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for ChipOne icn8318 i2c touchscreen controller
*
* Copyright (c) 2015 Red Hat Inc.
*
* Red Hat authors:
* Hans de Goede <[email protected]>
*/
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/module.h>
#include <linux/of.h>
#define ICN8318_REG_POWER 4
#define ICN8318_REG_TOUCHDATA 16
#define ICN8318_POWER_ACTIVE 0
#define ICN8318_POWER_MONITOR 1
#define ICN8318_POWER_HIBERNATE 2
#define ICN8318_MAX_TOUCHES 5
struct icn8318_touch {
__u8 slot;
__be16 x;
__be16 y;
__u8 pressure; /* Seems more like finger width then pressure really */
__u8 event;
/* The difference between 2 and 3 is unclear */
#define ICN8318_EVENT_NO_DATA 1 /* No finger seen yet since wakeup */
#define ICN8318_EVENT_UPDATE1 2 /* New or updated coordinates */
#define ICN8318_EVENT_UPDATE2 3 /* New or updated coordinates */
#define ICN8318_EVENT_END 4 /* Finger lifted */
} __packed;
struct icn8318_touch_data {
__u8 softbutton;
__u8 touch_count;
struct icn8318_touch touches[ICN8318_MAX_TOUCHES];
} __packed;
struct icn8318_data {
struct i2c_client *client;
struct input_dev *input;
struct gpio_desc *wake_gpio;
struct touchscreen_properties prop;
};
static int icn8318_read_touch_data(struct i2c_client *client,
struct icn8318_touch_data *touch_data)
{
u8 reg = ICN8318_REG_TOUCHDATA;
struct i2c_msg msg[2] = {
{
.addr = client->addr,
.len = 1,
.buf = ®
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = sizeof(struct icn8318_touch_data),
.buf = (u8 *)touch_data
}
};
return i2c_transfer(client->adapter, msg, 2);
}
static inline bool icn8318_touch_active(u8 event)
{
return (event == ICN8318_EVENT_UPDATE1) ||
(event == ICN8318_EVENT_UPDATE2);
}
static irqreturn_t icn8318_irq(int irq, void *dev_id)
{
struct icn8318_data *data = dev_id;
struct device *dev = &data->client->dev;
struct icn8318_touch_data touch_data;
int i, ret;
ret = icn8318_read_touch_data(data->client, &touch_data);
if (ret < 0) {
dev_err(dev, "Error reading touch data: %d\n", ret);
return IRQ_HANDLED;
}
if (touch_data.softbutton) {
/*
* Other data is invalid when a softbutton is pressed.
* This needs some extra devicetree bindings to map the icn8318
* softbutton codes to evdev codes. Currently no known devices
* use this.
*/
return IRQ_HANDLED;
}
if (touch_data.touch_count > ICN8318_MAX_TOUCHES) {
dev_warn(dev, "Too much touches %d > %d\n",
touch_data.touch_count, ICN8318_MAX_TOUCHES);
touch_data.touch_count = ICN8318_MAX_TOUCHES;
}
for (i = 0; i < touch_data.touch_count; i++) {
struct icn8318_touch *touch = &touch_data.touches[i];
bool act = icn8318_touch_active(touch->event);
input_mt_slot(data->input, touch->slot);
input_mt_report_slot_state(data->input, MT_TOOL_FINGER, act);
if (!act)
continue;
touchscreen_report_pos(data->input, &data->prop,
be16_to_cpu(touch->x),
be16_to_cpu(touch->y), true);
}
input_mt_sync_frame(data->input);
input_sync(data->input);
return IRQ_HANDLED;
}
static int icn8318_start(struct input_dev *dev)
{
struct icn8318_data *data = input_get_drvdata(dev);
enable_irq(data->client->irq);
gpiod_set_value_cansleep(data->wake_gpio, 1);
return 0;
}
static void icn8318_stop(struct input_dev *dev)
{
struct icn8318_data *data = input_get_drvdata(dev);
disable_irq(data->client->irq);
i2c_smbus_write_byte_data(data->client, ICN8318_REG_POWER,
ICN8318_POWER_HIBERNATE);
gpiod_set_value_cansleep(data->wake_gpio, 0);
}
static int icn8318_suspend(struct device *dev)
{
struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
mutex_lock(&data->input->mutex);
if (input_device_enabled(data->input))
icn8318_stop(data->input);
mutex_unlock(&data->input->mutex);
return 0;
}
static int icn8318_resume(struct device *dev)
{
struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
mutex_lock(&data->input->mutex);
if (input_device_enabled(data->input))
icn8318_start(data->input);
mutex_unlock(&data->input->mutex);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume);
static int icn8318_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct icn8318_data *data;
struct input_dev *input;
int error;
if (!client->irq) {
dev_err(dev, "Error no irq specified\n");
return -EINVAL;
}
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->wake_gpio = devm_gpiod_get(dev, "wake", GPIOD_OUT_LOW);
if (IS_ERR(data->wake_gpio))
return dev_err_probe(dev, PTR_ERR(data->wake_gpio), "Error getting wake gpio\n");
input = devm_input_allocate_device(dev);
if (!input)
return -ENOMEM;
input->name = client->name;
input->id.bustype = BUS_I2C;
input->open = icn8318_start;
input->close = icn8318_stop;
input->dev.parent = dev;
input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
touchscreen_parse_properties(input, true, &data->prop);
if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
!input_abs_get_max(input, ABS_MT_POSITION_Y)) {
dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
return -EINVAL;
}
error = input_mt_init_slots(input, ICN8318_MAX_TOUCHES,
INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
if (error)
return error;
data->client = client;
data->input = input;
input_set_drvdata(input, data);
error = devm_request_threaded_irq(dev, client->irq, NULL, icn8318_irq,
IRQF_ONESHOT, client->name, data);
if (error) {
dev_err(dev, "Error requesting irq: %d\n", error);
return error;
}
/* Stop device till opened */
icn8318_stop(data->input);
error = input_register_device(input);
if (error)
return error;
i2c_set_clientdata(client, data);
return 0;
}
static const struct of_device_id icn8318_of_match[] = {
{ .compatible = "chipone,icn8318" },
{ }
};
MODULE_DEVICE_TABLE(of, icn8318_of_match);
/* This is useless for OF-enabled devices, but it is needed by I2C subsystem */
static const struct i2c_device_id icn8318_i2c_id[] = {
{ },
};
MODULE_DEVICE_TABLE(i2c, icn8318_i2c_id);
static struct i2c_driver icn8318_driver = {
.driver = {
.name = "chipone_icn8318",
.pm = pm_sleep_ptr(&icn8318_pm_ops),
.of_match_table = icn8318_of_match,
},
.probe = icn8318_probe,
.id_table = icn8318_i2c_id,
};
module_i2c_driver(icn8318_driver);
MODULE_DESCRIPTION("ChipOne icn8318 I2C Touchscreen Driver");
MODULE_AUTHOR("Hans de Goede <[email protected]>");
MODULE_LICENSE("GPL");
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