Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Touch Screen driver for EETI's I2C connected touch screen panels
 *   Copyright (c) 2009,2018 Daniel Mack <daniel@zonque.org>
 *
 * See EETI's software guide for the protocol specification:
 *   http://home.eeti.com.tw/documentation.html
 *
 * Based on migor_ts.c
 *   Copyright (c) 2008 Magnus Damm
 *   Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>
 */
 
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/input/touchscreen.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/timer.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <asm/unaligned.h>
 
struct eeti_ts {
<------>struct i2c_client *client;
<------>struct input_dev *input;
<------>struct gpio_desc *attn_gpio;
<------>struct touchscreen_properties props;
<------>struct mutex mutex;
<------>bool running;
};
 
#define EETI_TS_BITDEPTH	(11)
#define EETI_MAXVAL		((1 << (EETI_TS_BITDEPTH + 1)) - 1)
 
#define REPORT_BIT_PRESSED	BIT(0)
#define REPORT_BIT_AD0		BIT(1)
#define REPORT_BIT_AD1		BIT(2)
#define REPORT_BIT_HAS_PRESSURE	BIT(6)
#define REPORT_RES_BITS(v)	(((v) >> 1) + EETI_TS_BITDEPTH)
 
static void eeti_ts_report_event(struct eeti_ts *eeti, u8 *buf)
{
<------>unsigned int res;
<------>u16 x, y;
 
<------>res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
 
<------>x = get_unaligned_be16(&buf[1]);
<------>y = get_unaligned_be16(&buf[3]);
 
<------>/* fix the range to 11 bits */
<------>x >>= res - EETI_TS_BITDEPTH;
<------>y >>= res - EETI_TS_BITDEPTH;
 
<------>if (buf[0] & REPORT_BIT_HAS_PRESSURE)
<------><------>input_report_abs(eeti->input, ABS_PRESSURE, buf[5]);
 
<------>touchscreen_report_pos(eeti->input, &eeti->props, x, y, false);
<------>input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED);
<------>input_sync(eeti->input);
}
 
static int eeti_ts_read(struct eeti_ts *eeti)
{
<------>int len, error;
<------>char buf[6];
 
<------>len = i2c_master_recv(eeti->client, buf, sizeof(buf));
<------>if (len != sizeof(buf)) {
<------><------>error = len < 0 ? len : -EIO;
<------><------>dev_err(&eeti->client->dev,
<------><------><------>"failed to read touchscreen data: %d\n",
<------><------><------>error);
<------><------>return error;
<------>}
 
<------>/* Motion packet */
<------>if (buf[0] & 0x80)
<------><------>eeti_ts_report_event(eeti, buf);
 
<------>return 0;
}
 
static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
{
<------>struct eeti_ts *eeti = dev_id;
<------>int error;
 
<------>mutex_lock(&eeti->mutex);
 
<------>do {
<------><------>/*
<------><------> * If we have attention GPIO, trust it. Otherwise we'll read
<------><------> * once and exit. We assume that in this case we are using
<------><------> * level triggered interrupt and it will get raised again
<------><------> * if/when there is more data.
<------><------> */
<------><------>if (eeti->attn_gpio &&
<------><------>    !gpiod_get_value_cansleep(eeti->attn_gpio)) {
<------><------><------>break;
<------><------>}
 
<------><------>error = eeti_ts_read(eeti);
<------><------>if (error)
<------><------><------>break;
 
<------>} while (eeti->running && eeti->attn_gpio);
 
<------>mutex_unlock(&eeti->mutex);
<------>return IRQ_HANDLED;
}
 
static void eeti_ts_start(struct eeti_ts *eeti)
{
<------>mutex_lock(&eeti->mutex);
 
<------>eeti->running = true;
<------>enable_irq(eeti->client->irq);
 
<------>/*
<------> * Kick the controller in case we are using edge interrupt and
<------> * we missed our edge while interrupt was disabled. We expect
<------> * the attention GPIO to be wired in this case.
<------> */
<------>if (eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio))
<------><------>eeti_ts_read(eeti);
 
<------>mutex_unlock(&eeti->mutex);
}
 
static void eeti_ts_stop(struct eeti_ts *eeti)
{
<------>/*
<------> * Not locking here, just setting a flag and expect that the
<------> * interrupt thread will notice the flag eventually.
<------> */
<------>eeti->running = false;
<------>wmb();
<------>disable_irq(eeti->client->irq);
}
 
static int eeti_ts_open(struct input_dev *dev)
{
<------>struct eeti_ts *eeti = input_get_drvdata(dev);
 
<------>eeti_ts_start(eeti);
 
<------>return 0;
}
 
static void eeti_ts_close(struct input_dev *dev)
{
<------>struct eeti_ts *eeti = input_get_drvdata(dev);
 
<------>eeti_ts_stop(eeti);
}
 
static int eeti_ts_probe(struct i2c_client *client,
<------><------><------> const struct i2c_device_id *idp)
{
<------>struct device *dev = &client->dev;
<------>struct eeti_ts *eeti;
<------>struct input_dev *input;
<------>int error;
 
<------>/*
<------> * In contrast to what's described in the datasheet, there seems
<------> * to be no way of probing the presence of that device using I2C
<------> * commands. So we need to blindly believe it is there, and wait
<------> * for interrupts to occur.
<------> */
 
<------>eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL);
<------>if (!eeti) {
<------><------>dev_err(dev, "failed to allocate driver data\n");
<------><------>return -ENOMEM;
<------>}
 
<------>mutex_init(&eeti->mutex);
 
<------>input = devm_input_allocate_device(dev);
<------>if (!input) {
<------><------>dev_err(dev, "Failed to allocate input device.\n");
<------><------>return -ENOMEM;
<------>}
 
<------>input_set_capability(input, EV_KEY, BTN_TOUCH);
 
<------>input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
<------>input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
<------>input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);
 
<------>touchscreen_parse_properties(input, false, &eeti->props);
 
<------>input->name = client->name;
<------>input->id.bustype = BUS_I2C;
<------>input->open = eeti_ts_open;
<------>input->close = eeti_ts_close;
 
<------>eeti->client = client;
<------>eeti->input = input;
 
<------>eeti->attn_gpio = devm_gpiod_get_optional(dev, "attn", GPIOD_IN);
<------>if (IS_ERR(eeti->attn_gpio))
<------><------>return PTR_ERR(eeti->attn_gpio);
 
<------>i2c_set_clientdata(client, eeti);
<------>input_set_drvdata(input, eeti);
 
<------>error = devm_request_threaded_irq(dev, client->irq,
<------><------><------><------><------>  NULL, eeti_ts_isr,
<------><------><------><------><------>  IRQF_ONESHOT,
<------><------><------><------><------>  client->name, eeti);
<------>if (error) {
<------><------>dev_err(dev, "Unable to request touchscreen IRQ: %d\n",
<------><------><------>error);
<------><------>return error;
<------>}
 
<------>/*
<------> * Disable the device for now. It will be enabled once the
<------> * input device is opened.
<------> */
<------>eeti_ts_stop(eeti);
 
<------>error = input_register_device(input);
<------>if (error)
<------><------>return error;
 
<------>return 0;
}
 
static int __maybe_unused eeti_ts_suspend(struct device *dev)
{
<------>struct i2c_client *client = to_i2c_client(dev);
<------>struct eeti_ts *eeti = i2c_get_clientdata(client);
<------>struct input_dev *input_dev = eeti->input;
 
<------>mutex_lock(&input_dev->mutex);
 
<------>if (input_dev->users)
<------><------>eeti_ts_stop(eeti);
 
<------>mutex_unlock(&input_dev->mutex);
 
<------>if (device_may_wakeup(&client->dev))
<------><------>enable_irq_wake(client->irq);
 
<------>return 0;
}
 
static int __maybe_unused eeti_ts_resume(struct device *dev)
{
<------>struct i2c_client *client = to_i2c_client(dev);
<------>struct eeti_ts *eeti = i2c_get_clientdata(client);
<------>struct input_dev *input_dev = eeti->input;
 
<------>if (device_may_wakeup(&client->dev))
<------><------>disable_irq_wake(client->irq);
 
<------>mutex_lock(&input_dev->mutex);
 
<------>if (input_dev->users)
<------><------>eeti_ts_start(eeti);
 
<------>mutex_unlock(&input_dev->mutex);
 
<------>return 0;
}
 
static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
 
static const struct i2c_device_id eeti_ts_id[] = {
<------>{ "eeti_ts", 0 },
<------>{ }
};
MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
 
#ifdef CONFIG_OF
static const struct of_device_id of_eeti_ts_match[] = {
<------>{ .compatible = "eeti,exc3000-i2c", },
<------>{ }
};
#endif
 
static struct i2c_driver eeti_ts_driver = {
<------>.driver = {
<------><------>.name = "eeti_ts",
<------><------>.pm = &eeti_ts_pm,
<------><------>.of_match_table = of_match_ptr(of_eeti_ts_match),
<------>},
<------>.probe = eeti_ts_probe,
<------>.id_table = eeti_ts_id,
};
 
module_i2c_driver(eeti_ts_driver);
 
MODULE_DESCRIPTION("EETI Touchscreen driver");
MODULE_AUTHOR("Daniel Mack <daniel@zonque.org>");
MODULE_LICENSE("GPL");