// 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 <linux/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; 	guard(mutex)(&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); 	return IRQ_HANDLED;} static void eeti_ts_start(struct eeti_ts *eeti){	guard(mutex)(&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);} 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){	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 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; 	scoped_guard(mutex, &input_dev->mutex) {		if (input_device_enabled(input_dev))			eeti_ts_stop(eeti);	} 	if (device_may_wakeup(&client->dev))		enable_irq_wake(client->irq); 	return 0;} static int 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); 	scoped_guard(mutex, &input_dev->mutex) {		if (input_device_enabled(input_dev))			eeti_ts_start(eeti);	} 	return 0;} static DEFINE_SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume); static const struct i2c_device_id eeti_ts_id[] = {	{ .name = "eeti_ts" },	{ }};MODULE_DEVICE_TABLE(i2c, eeti_ts_id); #ifdef CONFIG_OFstatic 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 = pm_sleep_ptr(&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");