// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for Novatek NT11205 i2c touchscreen controller as found
* on the Acer Iconia One 7 B1-750 tablet.
*
* Copyright (c) 2023 Hans de Goede <[email protected]>
*/
#include <linux/delay.h>
#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/unaligned.h>
#define NVT_TS_TOUCH_START 0x00
#define NVT_TS_TOUCH_SIZE 6
#define NVT_TS_PARAMETERS_START 0x78
/* These are offsets from NVT_TS_PARAMETERS_START */
#define NVT_TS_PARAMS_WIDTH 0x04
#define NVT_TS_PARAMS_HEIGHT 0x06
#define NVT_TS_PARAMS_MAX_TOUCH 0x09
#define NVT_TS_PARAMS_MAX_BUTTONS 0x0a
#define NVT_TS_PARAMS_IRQ_TYPE 0x0b
#define NVT_TS_PARAMS_WAKE_TYPE 0x0c
#define NVT_TS_PARAMS_CHIP_ID 0x0e
#define NVT_TS_PARAMS_SIZE 0x0f
#define NVT_TS_SUPPORTED_WAKE_TYPE 0x05
#define NVT_TS_SUPPORTED_CHIP_ID 0x05
#define NVT_TS_MAX_TOUCHES 10
#define NVT_TS_MAX_SIZE 4096
#define NVT_TS_TOUCH_INVALID 0xff
#define NVT_TS_TOUCH_SLOT_SHIFT 3
#define NVT_TS_TOUCH_TYPE_MASK GENMASK(2, 0)
#define NVT_TS_TOUCH_NEW 1
#define NVT_TS_TOUCH_UPDATE 2
#define NVT_TS_TOUCH_RELEASE 3
static const int nvt_ts_irq_type[4] = {
IRQF_TRIGGER_RISING,
IRQF_TRIGGER_FALLING,
IRQF_TRIGGER_LOW,
IRQF_TRIGGER_HIGH
};
struct nvt_ts_data {
struct i2c_client *client;
struct input_dev *input;
struct gpio_desc *reset_gpio;
struct touchscreen_properties prop;
int max_touches;
u8 buf[NVT_TS_TOUCH_SIZE * NVT_TS_MAX_TOUCHES];
};
static int nvt_ts_read_data(struct i2c_client *client, u8 reg, u8 *data, int count)
{
struct i2c_msg msg[2] = {
{
.addr = client->addr,
.len = 1,
.buf = ®,
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = count,
.buf = data,
}
};
int ret;
ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
if (ret != ARRAY_SIZE(msg)) {
dev_err(&client->dev, "Error reading from 0x%02x: %d\n", reg, ret);
return (ret < 0) ? ret : -EIO;
}
return 0;
}
static irqreturn_t nvt_ts_irq(int irq, void *dev_id)
{
struct nvt_ts_data *data = dev_id;
struct device *dev = &data->client->dev;
int i, error, slot, x, y;
bool active;
u8 *touch;
error = nvt_ts_read_data(data->client, NVT_TS_TOUCH_START, data->buf,
data->max_touches * NVT_TS_TOUCH_SIZE);
if (error)
return IRQ_HANDLED;
for (i = 0; i < data->max_touches; i++) {
touch = &data->buf[i * NVT_TS_TOUCH_SIZE];
if (touch[0] == NVT_TS_TOUCH_INVALID)
continue;
slot = touch[0] >> NVT_TS_TOUCH_SLOT_SHIFT;
if (slot < 1 || slot > data->max_touches) {
dev_warn(dev, "slot %d out of range, ignoring\n", slot);
continue;
}
switch (touch[0] & NVT_TS_TOUCH_TYPE_MASK) {
case NVT_TS_TOUCH_NEW:
case NVT_TS_TOUCH_UPDATE:
active = true;
break;
case NVT_TS_TOUCH_RELEASE:
active = false;
break;
default:
dev_warn(dev, "slot %d unknown state %d\n", slot, touch[0] & 7);
continue;
}
slot--;
x = (touch[1] << 4) | (touch[3] >> 4);
y = (touch[2] << 4) | (touch[3] & 0x0f);
input_mt_slot(data->input, slot);
input_mt_report_slot_state(data->input, MT_TOOL_FINGER, active);
touchscreen_report_pos(data->input, &data->prop, x, y, true);
}
input_mt_sync_frame(data->input);
input_sync(data->input);
return IRQ_HANDLED;
}
static int nvt_ts_start(struct input_dev *dev)
{
struct nvt_ts_data *data = input_get_drvdata(dev);
enable_irq(data->client->irq);
gpiod_set_value_cansleep(data->reset_gpio, 0);
return 0;
}
static void nvt_ts_stop(struct input_dev *dev)
{
struct nvt_ts_data *data = input_get_drvdata(dev);
disable_irq(data->client->irq);
gpiod_set_value_cansleep(data->reset_gpio, 1);
}
static int nvt_ts_suspend(struct device *dev)
{
struct nvt_ts_data *data = i2c_get_clientdata(to_i2c_client(dev));
mutex_lock(&data->input->mutex);
if (input_device_enabled(data->input))
nvt_ts_stop(data->input);
mutex_unlock(&data->input->mutex);
return 0;
}
static int nvt_ts_resume(struct device *dev)
{
struct nvt_ts_data *data = i2c_get_clientdata(to_i2c_client(dev));
mutex_lock(&data->input->mutex);
if (input_device_enabled(data->input))
nvt_ts_start(data->input);
mutex_unlock(&data->input->mutex);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(nvt_ts_pm_ops, nvt_ts_suspend, nvt_ts_resume);
static int nvt_ts_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
int error, width, height, irq_type;
struct nvt_ts_data *data;
struct input_dev *input;
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->client = client;
i2c_set_clientdata(client, data);
data->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
error = PTR_ERR_OR_ZERO(data->reset_gpio);
if (error) {
dev_err(dev, "failed to request reset GPIO: %d\n", error);
return error;
}
/* Wait for controller to come out of reset before params read */
msleep(100);
error = nvt_ts_read_data(data->client, NVT_TS_PARAMETERS_START,
data->buf, NVT_TS_PARAMS_SIZE);
gpiod_set_value_cansleep(data->reset_gpio, 1); /* Put back in reset */
if (error)
return error;
width = get_unaligned_be16(&data->buf[NVT_TS_PARAMS_WIDTH]);
height = get_unaligned_be16(&data->buf[NVT_TS_PARAMS_HEIGHT]);
data->max_touches = data->buf[NVT_TS_PARAMS_MAX_TOUCH];
irq_type = data->buf[NVT_TS_PARAMS_IRQ_TYPE];
if (width > NVT_TS_MAX_SIZE || height >= NVT_TS_MAX_SIZE ||
data->max_touches > NVT_TS_MAX_TOUCHES ||
irq_type >= ARRAY_SIZE(nvt_ts_irq_type) ||
data->buf[NVT_TS_PARAMS_WAKE_TYPE] != NVT_TS_SUPPORTED_WAKE_TYPE ||
data->buf[NVT_TS_PARAMS_CHIP_ID] != NVT_TS_SUPPORTED_CHIP_ID) {
dev_err(dev, "Unsupported touchscreen parameters: %*ph\n",
NVT_TS_PARAMS_SIZE, data->buf);
return -EIO;
}
dev_dbg(dev, "Detected %dx%d touchscreen with %d max touches\n",
width, height, data->max_touches);
if (data->buf[NVT_TS_PARAMS_MAX_BUTTONS])
dev_warn(dev, "Touchscreen buttons are not supported\n");
input = devm_input_allocate_device(dev);
if (!input)
return -ENOMEM;
input->name = client->name;
input->id.bustype = BUS_I2C;
input->open = nvt_ts_start;
input->close = nvt_ts_stop;
input_set_abs_params(input, ABS_MT_POSITION_X, 0, width - 1, 0, 0);
input_set_abs_params(input, ABS_MT_POSITION_Y, 0, height - 1, 0, 0);
touchscreen_parse_properties(input, true, &data->prop);
error = input_mt_init_slots(input, data->max_touches,
INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
if (error)
return error;
data->input = input;
input_set_drvdata(input, data);
error = devm_request_threaded_irq(dev, client->irq, NULL, nvt_ts_irq,
IRQF_ONESHOT | IRQF_NO_AUTOEN |
nvt_ts_irq_type[irq_type],
client->name, data);
if (error) {
dev_err(dev, "failed to request irq: %d\n", error);
return error;
}
error = input_register_device(input);
if (error) {
dev_err(dev, "failed to register input device: %d\n", error);
return error;
}
return 0;
}
static const struct i2c_device_id nvt_ts_i2c_id[] = {
{ "NVT-ts" },
{ }
};
MODULE_DEVICE_TABLE(i2c, nvt_ts_i2c_id);
static struct i2c_driver nvt_ts_driver = {
.driver = {
.name = "novatek-nvt-ts",
.pm = pm_sleep_ptr(&nvt_ts_pm_ops),
},
.probe = nvt_ts_probe,
.id_table = nvt_ts_i2c_id,
};
module_i2c_driver(nvt_ts_driver);
MODULE_DESCRIPTION("Novatek NT11205 touchscreen driver");
MODULE_AUTHOR("Hans de Goede <[email protected]>");
MODULE_LICENSE("GPL");
Codebase Browser
linux