/*
* Driver for ELAN eKTF2127 i2c touchscreen controller
*
* For this driver the layout of the Chipone icn8318 i2c
* touchscreencontroller is used.
*
* 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.
*
* Author:
* Michel Verlaan <michel.verl@gmail.com>
* Siebren Vroegindeweij <siebren.vroegindeweij@hotmail.com>
*
* Original chipone_icn8318 driver:
* Hans de Goede <hdegoede@redhat.com>
*/
#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>
#include <linux/delay.h>
/* Packet header defines (first byte of data send / received) */
#define EKTF2127_NOISE 0x40
#define EKTF2127_RESPONSE 0x52
#define EKTF2127_REQUEST 0x53
#define EKTF2127_HELLO 0x55
#define EKTF2127_REPORT 0x5d
#define EKTF2127_CALIB_DONE 0x66
/* Register defines (second byte of data send / received) */
#define EKTF2127_ENV_NOISY 0x41
#define EKTF2127_HEIGHT 0x60
#define EKTF2127_WIDTH 0x63
/* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */
#define EKTF2127_TOUCH_REPORT_SIZE 21
#define EKTF2127_MAX_TOUCHES 5
struct ektf2127_ts {
struct i2c_client *client;
struct input_dev *input;
struct gpio_desc *power_gpios;
struct touchscreen_properties prop;
};
static void ektf2127_parse_coordinates(const u8* buf, unsigned int touch_count,
struct input_mt_pos *touches)
{
int index = 0;
int i;
for (i = 0; i < touch_count; i++) {
index = 2 + i * 3;
touches[i].x = (buf[index] & 0x0f);
touches[i].x <<= 8;
touches[i].x |= buf[index + 2];
touches[i].y = (buf[index] & 0xf0);
touches[i].y <<= 4;
touches[i].y |= buf[index + 1];
}
}
static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf)
{
struct input_mt_pos touches[EKTF2127_MAX_TOUCHES];
int slots[EKTF2127_MAX_TOUCHES];
unsigned int touch_count, i;
touch_count = buf[1] & 0x07;
if (touch_count > EKTF2127_MAX_TOUCHES) {
dev_err(&ts->client->dev,
"Too many touches %d > %d\n",
touch_count, EKTF2127_MAX_TOUCHES);
touch_count = EKTF2127_MAX_TOUCHES;
}
ektf2127_parse_coordinates(buf, touch_count, touches);
input_mt_assign_slots(ts->input, slots, touches,
touch_count, 0);
for (i = 0; i < touch_count; i++) {
input_mt_slot(ts->input, slots[i]);
input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
touchscreen_report_pos(ts->input, &ts->prop,
touches[i].x, touches[i].y, true);
}
input_mt_sync_frame(ts->input);
input_sync(ts->input);
}
static irqreturn_t ektf2127_irq(int irq, void *dev_id)
{
struct ektf2127_ts *ts = dev_id;
struct device *dev = &ts->client->dev;
char buf[EKTF2127_TOUCH_REPORT_SIZE];
int ret;
ret = i2c_master_recv(ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE);
if (ret != EKTF2127_TOUCH_REPORT_SIZE) {
dev_err(dev, "Error reading touch data: %d\n", ret);
goto out;
}
switch (buf[0]) {
case EKTF2127_REPORT:
ektf2127_report_event(ts, buf);
break;
case EKTF2127_NOISE:
if (buf[1] == EKTF2127_ENV_NOISY)
dev_dbg(dev, "Environment is electrically noisy\n");
break;
case EKTF2127_HELLO:
case EKTF2127_CALIB_DONE:
break;
default:
dev_err(dev, "Unexpected packet header byte %#02x\n", buf[0]);
break;
}
out:
return IRQ_HANDLED;
}
static int ektf2127_start(struct input_dev *dev)
{
struct ektf2127_ts *ts = input_get_drvdata(dev);
enable_irq(ts->client->irq);
gpiod_set_value_cansleep(ts->power_gpios, 1);
return 0;
}
static void ektf2127_stop(struct input_dev *dev)
{
struct ektf2127_ts *ts = input_get_drvdata(dev);
disable_irq(ts->client->irq);
gpiod_set_value_cansleep(ts->power_gpios, 0);
}
static int __maybe_unused ektf2127_suspend(struct device *dev)
{
struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
mutex_lock(&ts->input->mutex);
if (ts->input->users)
ektf2127_stop(ts->input);
mutex_unlock(&ts->input->mutex);
return 0;
}
static int __maybe_unused ektf2127_resume(struct device *dev)
{
struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
mutex_lock(&ts->input->mutex);
if (ts->input->users)
ektf2127_start(ts->input);
mutex_unlock(&ts->input->mutex);
return 0;
}
static SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend,
ektf2127_resume);
static int ektf2127_query_dimension(struct i2c_client *client, bool width)
{
struct device *dev = &client->dev;
const char *what = width ? "width" : "height";
u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
u8 buf[4];
int ret;
int error;
/* Request dimension */
buf[0] = EKTF2127_REQUEST;
buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
buf[2] = 0x00;
buf[3] = 0x00;
ret = i2c_master_send(client, buf, sizeof(buf));
if (ret != sizeof(buf)) {
error = ret < 0 ? ret : -EIO;
dev_err(dev, "Failed to request %s: %d\n", what, error);
return error;
}
msleep(20);
/* Read response */
ret = i2c_master_recv(client, buf, sizeof(buf));
if (ret != sizeof(buf)) {
error = ret < 0 ? ret : -EIO;
dev_err(dev, "Failed to receive %s data: %d\n", what, error);
return error;
}
if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) {
dev_err(dev, "Unexpected %s data: %#02x %#02x\n",
what, buf[0], buf[1]);
return -EIO;
}
return (((buf[3] & 0xf0) << 4) | buf[2]) - 1;
}
static int ektf2127_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct ektf2127_ts *ts;
struct input_dev *input;
u8 buf[4];
int max_x, max_y;
int error;
if (!client->irq) {
dev_err(dev, "Error no irq specified\n");
return -EINVAL;
}
ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
if (!ts)
return -ENOMEM;
/* This requests the gpio *and* turns on the touchscreen controller */
ts->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH);
if (IS_ERR(ts->power_gpios)) {
error = PTR_ERR(ts->power_gpios);
if (error != -EPROBE_DEFER)
dev_err(dev, "Error getting power gpio: %d\n", error);
return error;
}
input = devm_input_allocate_device(dev);
if (!input)
return -ENOMEM;
input->name = client->name;
input->id.bustype = BUS_I2C;
input->open = ektf2127_start;
input->close = ektf2127_stop;
ts->client = client;
/* Read hello (ignore result, depends on initial power state) */
msleep(20);
i2c_master_recv(ts->client, buf, sizeof(buf));
/* Read resolution from chip */
max_x = ektf2127_query_dimension(client, true);
if (max_x < 0)
return max_x;
max_y = ektf2127_query_dimension(client, false);
if (max_y < 0)
return max_y;
input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
touchscreen_parse_properties(input, true, &ts->prop);
error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES,
INPUT_MT_DIRECT |
INPUT_MT_DROP_UNUSED |
INPUT_MT_TRACK);
if (error)
return error;
ts->input = input;
input_set_drvdata(input, ts);
error = devm_request_threaded_irq(dev, client->irq,
NULL, ektf2127_irq,
IRQF_ONESHOT, client->name, ts);
if (error) {
dev_err(dev, "Error requesting irq: %d\n", error);
return error;
}
/* Stop device till opened */
ektf2127_stop(ts->input);
error = input_register_device(input);
if (error)
return error;
i2c_set_clientdata(client, ts);
return 0;
}
#ifdef [31mCONFIG_OF[0m
static const struct of_device_id ektf2127_of_match[] = {
{ .compatible = "elan,ektf2127" },
{}
};
MODULE_DEVICE_TABLE(of, ektf2127_of_match);
#endif
static const struct i2c_device_id ektf2127_i2c_id[] = {
{ "ektf2127", 0 },
{}
};
MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id);
static struct i2c_driver ektf2127_driver = {
.driver = {
.name = "elan_ektf2127",
.pm = &ektf2127_pm_ops,
.of_match_table = of_match_ptr(ektf2127_of_match),
},
.probe = ektf2127_probe,
.id_table = ektf2127_i2c_id,
};
module_i2c_driver(ektf2127_driver);
MODULE_DESCRIPTION("ELAN eKTF2127 I2C Touchscreen Driver");
MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij");
MODULE_LICENSE("GPL");