[mirror_ubuntu-eoan-kernel.git] / drivers / input / touchscreen / eeti_ts.c

/*
 * 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>
 *
 * This file 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.
 *
 * This file is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#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;
	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 irqreturn_t eeti_ts_isr(int irq, void *dev_id)
{
	struct eeti_ts *eeti = dev_id;
	int len;
	int error;
	char buf[6];

	do {
		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);
			break;
		}

		if (buf[0] & 0x80) {
			/* Motion packet */
			eeti_ts_report_event(eeti, buf);
		}
	} while (eeti->running &&
		 eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio));

	return IRQ_HANDLED;
}

static void eeti_ts_start(struct eeti_ts *eeti)
{
	eeti->running = true;
	wmb();
	enable_irq(eeti->client->irq);
}

static void eeti_ts_stop(struct eeti_ts *eeti)
{
	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;
	}

	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");
Commit	Line	Data
10494dce DM	1	/*
10494dce DM	2	* Touch Screen driver for EETI's I2C connected touch screen panels
fd8135b6	3	* Copyright (c) 2009,2018 Daniel Mack <daniel@zonque.org>
10494dce DM	4	*
10494dce DM	5	* See EETI's software guide for the protocol specification:
fd8135b6	6	* http://home.eeti.com.tw/documentation.html
10494dce DM	7	*
	8	* Based on migor_ts.c
	9	* Copyright (c) 2008 Magnus Damm
	10	* Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>
	11	*
	12	* This file is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU General Public
	14	* License as published by the Free Software Foundation; either
	15	* version 2 of the License, or (at your option) any later version.
	16	*
	17	* This file is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	20	* General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU General Public
	23	* License along with this library; if not, write to the Free Software
	24	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	25	*/
	26
	27	#include <linux/module.h>
10494dce DM	28	#include <linux/kernel.h>
10494dce DM	29	#include <linux/input.h>
a114cbd0	30	#include <linux/input/touchscreen.h>
10494dce DM	31	#include <linux/interrupt.h>
	32	#include <linux/i2c.h>
	33	#include <linux/timer.h>
d99caa47	34	#include <linux/gpio/consumer.h>
e32d7f1b	35	#include <linux/of.h>
5a0e3ad6	36	#include <linux/slab.h>
e9f66cdb	37	#include <asm/unaligned.h>
10494dce	38
720bebdf	39	struct eeti_ts {
10494dce DM	40	struct i2c_client *client;
10494dce DM	41	struct input_dev *input;
d99caa47	42	struct gpio_desc *attn_gpio;
a114cbd0	43	struct touchscreen_properties props;
0378008a	44	bool running;
10494dce DM	45	};
	46
	47	#define EETI_TS_BITDEPTH (11)
	48	#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1)
	49
272c03bb DT	50	#define REPORT_BIT_PRESSED BIT(0)
	51	#define REPORT_BIT_AD0 BIT(1)
	52	#define REPORT_BIT_AD1 BIT(2)
	53	#define REPORT_BIT_HAS_PRESSURE BIT(6)
10494dce DM	54	#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
10494dce DM	55
0378008a	56	static void eeti_ts_report_event(struct eeti_ts eeti, u8 buf)
10494dce	57	{
0378008a DT	58	unsigned int res;
0378008a DT	59	u16 x, y;
10494dce	60
10494dce	61	res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 \| REPORT_BIT_AD1));
e9f66cdb DT	62
	63	x = get_unaligned_be16(&buf[1]);
	64	y = get_unaligned_be16(&buf[3]);
10494dce DM	65
	66	/* fix the range to 11 bits */
	67	x >>= res - EETI_TS_BITDEPTH;
	68	y >>= res - EETI_TS_BITDEPTH;
	69
10494dce	70	if (buf[0] & REPORT_BIT_HAS_PRESSURE)
720bebdf	71	input_report_abs(eeti->input, ABS_PRESSURE, buf[5]);
10494dce	72
a114cbd0	73	touchscreen_report_pos(eeti->input, &eeti->props, x, y, false);
0378008a	74	input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED);
720bebdf	75	input_sync(eeti->input);
10494dce DM	76	}
	77
	78	static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
	79	{
720bebdf	80	struct eeti_ts *eeti = dev_id;
0378008a DT	81	int len;
	82	int error;
	83	char buf[6];
10494dce	84
0378008a DT	85	do {
	86	len = i2c_master_recv(eeti->client, buf, sizeof(buf));
	87	if (len != sizeof(buf)) {
	88	error = len < 0 ? len : -EIO;
	89	dev_err(&eeti->client->dev,
	90	"failed to read touchscreen data: %d\n",
	91	error);
	92	break;
	93	}
	94
	95	if (buf[0] & 0x80) {
	96	/* Motion packet */
	97	eeti_ts_report_event(eeti, buf);
	98	}
d99caa47 DT	99	} while (eeti->running &&
d99caa47 DT	100	eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio));
10494dce DM	101
	102	return IRQ_HANDLED;
	103	}
	104
720bebdf	105	static void eeti_ts_start(struct eeti_ts *eeti)
10494dce	106	{
0378008a DT	107	eeti->running = true;
0378008a DT	108	wmb();
2d388499	109	enable_irq(eeti->client->irq);
7fbef0d1 DM	110	}
7fbef0d1 DM	111
720bebdf	112	static void eeti_ts_stop(struct eeti_ts *eeti)
7fbef0d1	113	{
0378008a DT	114	eeti->running = false;
0378008a DT	115	wmb();
2d388499	116	disable_irq(eeti->client->irq);
7fbef0d1 DM	117	}
	118
	119	static int eeti_ts_open(struct input_dev *dev)
	120	{
720bebdf	121	struct eeti_ts *eeti = input_get_drvdata(dev);
7fbef0d1	122
720bebdf	123	eeti_ts_start(eeti);
10494dce DM	124
	125	return 0;
	126	}
	127
	128	static void eeti_ts_close(struct input_dev *dev)
	129	{
720bebdf	130	struct eeti_ts *eeti = input_get_drvdata(dev);
10494dce	131
720bebdf	132	eeti_ts_stop(eeti);
10494dce DM	133	}
10494dce DM	134
5298cc4c	135	static int eeti_ts_probe(struct i2c_client *client,
6f9fab69	136	const struct i2c_device_id *idp)
10494dce	137	{
6f9fab69	138	struct device *dev = &client->dev;
720bebdf	139	struct eeti_ts *eeti;
10494dce	140	struct input_dev *input;
6f9fab69	141	int error;
10494dce	142
7fbef0d1 DM	143	/*
7fbef0d1 DM	144	* In contrast to what's described in the datasheet, there seems
10494dce DM	145	* to be no way of probing the presence of that device using I2C
10494dce DM	146	* commands. So we need to blindly believe it is there, and wait
7fbef0d1 DM	147	* for interrupts to occur.
7fbef0d1 DM	148	*/
10494dce	149
6f9fab69	150	eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL);
720bebdf	151	if (!eeti) {
6f9fab69	152	dev_err(dev, "failed to allocate driver data\n");
ad03ae44	153	return -ENOMEM;
10494dce DM	154	}
10494dce DM	155
6f9fab69	156	input = devm_input_allocate_device(dev);
10494dce	157	if (!input) {
6f9fab69 DT	158	dev_err(dev, "Failed to allocate input device.\n");
6f9fab69 DT	159	return -ENOMEM;
10494dce DM	160	}
10494dce DM	161
42e02a6a	162	input_set_capability(input, EV_KEY, BTN_TOUCH);
10494dce DM	163
	164	input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
	165	input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
	166	input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);
	167
a114cbd0 DM	168	touchscreen_parse_properties(input, false, &eeti->props);
a114cbd0 DM	169
10494dce DM	170	input->name = client->name;
10494dce DM	171	input->id.bustype = BUS_I2C;
10494dce DM	172	input->open = eeti_ts_open;
	173	input->close = eeti_ts_close;
	174
720bebdf DT	175	eeti->client = client;
720bebdf DT	176	eeti->input = input;
25a70e38	177
d99caa47 DT	178	eeti->attn_gpio = devm_gpiod_get_optional(dev, "attn", GPIOD_IN);
	179	if (IS_ERR(eeti->attn_gpio))
	180	return PTR_ERR(eeti->attn_gpio);
25a70e38	181
720bebdf DT	182	i2c_set_clientdata(client, eeti);
720bebdf DT	183	input_set_drvdata(input, eeti);
10494dce	184
0378008a DT	185	error = devm_request_threaded_irq(dev, client->irq,
0378008a DT	186	NULL, eeti_ts_isr,
d422be5f	187	IRQF_ONESHOT,
0378008a	188	client->name, eeti);
6f9fab69 DT	189	if (error) {
	190	dev_err(dev, "Unable to request touchscreen IRQ: %d\n",
	191	error);
	192	return error;
10494dce DM	193	}
10494dce DM	194
7fbef0d1 DM	195	/*
	196	* Disable the device for now. It will be enabled once the
	197	* input device is opened.
	198	*/
720bebdf	199	eeti_ts_stop(eeti);
10494dce	200
0378008a DT	201	error = input_register_device(input);
	202	if (error)
	203	return error;
	204
10494dce DM	205	return 0;
	206	}
	207
02b6a58b	208	static int __maybe_unused eeti_ts_suspend(struct device *dev)
10494dce	209	{
85012fff	210	struct i2c_client *client = to_i2c_client(dev);
720bebdf DT	211	struct eeti_ts *eeti = i2c_get_clientdata(client);
720bebdf DT	212	struct input_dev *input_dev = eeti->input;
7fbef0d1 DM	213
	214	mutex_lock(&input_dev->mutex);
	215
	216	if (input_dev->users)
720bebdf	217	eeti_ts_stop(eeti);
7fbef0d1 DM	218
7fbef0d1 DM	219	mutex_unlock(&input_dev->mutex);
10494dce DM	220
10494dce DM	221	if (device_may_wakeup(&client->dev))
2d388499	222	enable_irq_wake(client->irq);
10494dce DM	223
	224	return 0;
	225	}
	226
02b6a58b	227	static int __maybe_unused eeti_ts_resume(struct device *dev)
10494dce	228	{
85012fff	229	struct i2c_client *client = to_i2c_client(dev);
720bebdf DT	230	struct eeti_ts *eeti = i2c_get_clientdata(client);
720bebdf DT	231	struct input_dev *input_dev = eeti->input;
10494dce DM	232
10494dce DM	233	if (device_may_wakeup(&client->dev))
2d388499	234	disable_irq_wake(client->irq);
10494dce	235
7fbef0d1 DM	236	mutex_lock(&input_dev->mutex);
	237
	238	if (input_dev->users)
720bebdf	239	eeti_ts_start(eeti);
7fbef0d1 DM	240
	241	mutex_unlock(&input_dev->mutex);
	242
10494dce DM	243	return 0;
10494dce DM	244	}
85012fff MB	245
85012fff MB	246	static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
10494dce DM	247
	248	static const struct i2c_device_id eeti_ts_id[] = {
	249	{ "eeti_ts", 0 },
	250	{ }
	251	};
	252	MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
	253
e32d7f1b DM	254	#ifdef CONFIG_OF
	255	static const struct of_device_id of_eeti_ts_match[] = {
	256	{ .compatible = "eeti,exc3000-i2c", },
	257	{ }
	258	};
	259	#endif
	260
10494dce DM	261	static struct i2c_driver eeti_ts_driver = {
	262	.driver = {
	263	.name = "eeti_ts",
85012fff	264	.pm = &eeti_ts_pm,
e32d7f1b	265	.of_match_table = of_match_ptr(of_eeti_ts_match),
10494dce DM	266	},
10494dce DM	267	.probe = eeti_ts_probe,
10494dce DM	268	.id_table = eeti_ts_id,
	269	};
	270
1b92c1cf	271	module_i2c_driver(eeti_ts_driver);
10494dce DM	272
10494dce DM	273	MODULE_DESCRIPTION("EETI Touchscreen driver");
fd8135b6	274	MODULE_AUTHOR("Daniel Mack <daniel@zonque.org>");
10494dce	275	MODULE_LICENSE("GPL");