1/*
  2 * Driver for Semtech SX8654 I2C touchscreen controller.
  3 *
  4 * Copyright (c) 2015 Armadeus Systems
  5 *	Sébastien Szymanski <sebastien.szymanski@armadeus.com>
  6 *
  7 * Using code from:
  8 *  - sx865x.c
  9 *	Copyright (c) 2013 U-MoBo Srl
 10 *	Pierluigi Passaro <p.passaro@u-mobo.com>
 11 *  - sx8650.c
 12 *      Copyright (c) 2009 Wayne Roberts
 13 *  - tsc2007.c
 14 *      Copyright (c) 2008 Kwangwoo Lee
 15 *  - ads7846.c
 16 *      Copyright (c) 2005 David Brownell
 17 *      Copyright (c) 2006 Nokia Corporation
 18 *  - corgi_ts.c
 19 *      Copyright (C) 2004-2005 Richard Purdie
 20 *  - omap_ts.[hc], ads7846.h, ts_osk.c
 21 *      Copyright (C) 2002 MontaVista Software
 22 *      Copyright (C) 2004 Texas Instruments
 23 *      Copyright (C) 2005 Dirk Behme
 24 *
 25 *  This program is free software; you can redistribute it and/or modify
 26 *  it under the terms of the GNU General Public License version 2 as
 27 *  published by the Free Software Foundation.
 28 */
 29
 30#include <linux/input.h>
 31#include <linux/module.h>
 32#include <linux/of.h>
 33#include <linux/i2c.h>
 34#include <linux/interrupt.h>
 35#include <linux/irq.h>
 36
 37/* register addresses */
 38#define I2C_REG_TOUCH0			0x00
 39#define I2C_REG_TOUCH1			0x01
 40#define I2C_REG_CHANMASK		0x04
 41#define I2C_REG_IRQMASK			0x22
 42#define I2C_REG_IRQSRC			0x23
 43#define I2C_REG_SOFTRESET		0x3f
 44
 45/* commands */
 46#define CMD_READ_REGISTER		0x40
 47#define CMD_MANUAL			0xc0
 48#define CMD_PENTRG			0xe0
 49
 50/* value for I2C_REG_SOFTRESET */
 51#define SOFTRESET_VALUE			0xde
 52
 53/* bits for I2C_REG_IRQSRC */
 54#define IRQ_PENTOUCH_TOUCHCONVDONE	0x08
 55#define IRQ_PENRELEASE			0x04
 56
 57/* bits for RegTouch1 */
 58#define CONDIRQ				0x20
 59#define FILT_7SA			0x03
 60
 61/* bits for I2C_REG_CHANMASK */
 62#define CONV_X				0x80
 63#define CONV_Y				0x40
 64
 65/* coordinates rate: higher nibble of CTRL0 register */
 66#define RATE_MANUAL			0x00
 67#define RATE_5000CPS			0xf0
 68
 69/* power delay: lower nibble of CTRL0 register */
 70#define POWDLY_1_1MS			0x0b
 71
 72#define MAX_12BIT			((1 << 12) - 1)
 73
 74struct sx8654 {
 75	struct input_dev *input;
 76	struct i2c_client *client;
 77};
 78
 79static irqreturn_t sx8654_irq(int irq, void *handle)
 80{
 81	struct sx8654 *sx8654 = handle;
 82	int irqsrc;
 83	u8 data[4];
 84	unsigned int x, y;
 85	int retval;
 86
 87	irqsrc = i2c_smbus_read_byte_data(sx8654->client,
 88					  CMD_READ_REGISTER | I2C_REG_IRQSRC);
 89	dev_dbg(&sx8654->client->dev, "irqsrc = 0x%x", irqsrc);
 90
 91	if (irqsrc < 0)
 92		goto out;
 93
 94	if (irqsrc & IRQ_PENRELEASE) {
 95		dev_dbg(&sx8654->client->dev, "pen release interrupt");
 96
 97		input_report_key(sx8654->input, BTN_TOUCH, 0);
 98		input_sync(sx8654->input);
 99	}
100
101	if (irqsrc & IRQ_PENTOUCH_TOUCHCONVDONE) {
102		dev_dbg(&sx8654->client->dev, "pen touch interrupt");
103
104		retval = i2c_master_recv(sx8654->client, data, sizeof(data));
105		if (retval != sizeof(data))
106			goto out;
107
108		/* invalid data */
109		if (unlikely(data[0] & 0x80 || data[2] & 0x80))
110			goto out;
111
112		x = ((data[0] & 0xf) << 8) | (data[1]);
113		y = ((data[2] & 0xf) << 8) | (data[3]);
114
115		input_report_abs(sx8654->input, ABS_X, x);
116		input_report_abs(sx8654->input, ABS_Y, y);
117		input_report_key(sx8654->input, BTN_TOUCH, 1);
118		input_sync(sx8654->input);
119
120		dev_dbg(&sx8654->client->dev, "point(%4d,%4d)\n", x, y);
121	}
122
123out:
124	return IRQ_HANDLED;
125}
126
127static int sx8654_open(struct input_dev *dev)
128{
129	struct sx8654 *sx8654 = input_get_drvdata(dev);
130	struct i2c_client *client = sx8654->client;
131	int error;
132
133	/* enable pen trigger mode */
134	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0,
135					  RATE_5000CPS | POWDLY_1_1MS);
136	if (error) {
137		dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
138		return error;
139	}
140
141	error = i2c_smbus_write_byte(client, CMD_PENTRG);
142	if (error) {
143		dev_err(&client->dev, "writing command CMD_PENTRG failed");
144		return error;
145	}
146
147	enable_irq(client->irq);
148
149	return 0;
150}
151
152static void sx8654_close(struct input_dev *dev)
153{
154	struct sx8654 *sx8654 = input_get_drvdata(dev);
155	struct i2c_client *client = sx8654->client;
156	int error;
157
158	disable_irq(client->irq);
159
160	/* enable manual mode mode */
161	error = i2c_smbus_write_byte(client, CMD_MANUAL);
162	if (error) {
163		dev_err(&client->dev, "writing command CMD_MANUAL failed");
164		return;
165	}
166
167	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0, 0);
168	if (error) {
169		dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
170		return;
171	}
172}
173
174static int sx8654_probe(struct i2c_client *client,
175			const struct i2c_device_id *id)
176{
177	struct sx8654 *sx8654;
178	struct input_dev *input;
179	int error;
180
181	if (!i2c_check_functionality(client->adapter,
182				     I2C_FUNC_SMBUS_READ_WORD_DATA))
183		return -ENXIO;
184
185	sx8654 = devm_kzalloc(&client->dev, sizeof(*sx8654), GFP_KERNEL);
186	if (!sx8654)
187		return -ENOMEM;
188
189	input = devm_input_allocate_device(&client->dev);
190	if (!input)
191		return -ENOMEM;
192
193	input->name = "SX8654 I2C Touchscreen";
194	input->id.bustype = BUS_I2C;
195	input->dev.parent = &client->dev;
196	input->open = sx8654_open;
197	input->close = sx8654_close;
198
199	__set_bit(INPUT_PROP_DIRECT, input->propbit);
200	input_set_capability(input, EV_KEY, BTN_TOUCH);
201	input_set_abs_params(input, ABS_X, 0, MAX_12BIT, 0, 0);
202	input_set_abs_params(input, ABS_Y, 0, MAX_12BIT, 0, 0);
203
204	sx8654->client = client;
205	sx8654->input = input;
206
207	input_set_drvdata(sx8654->input, sx8654);
208
209	error = i2c_smbus_write_byte_data(client, I2C_REG_SOFTRESET,
210					  SOFTRESET_VALUE);
211	if (error) {
212		dev_err(&client->dev, "writing softreset value failed");
213		return error;
214	}
215
216	error = i2c_smbus_write_byte_data(client, I2C_REG_CHANMASK,
217					  CONV_X | CONV_Y);
218	if (error) {
219		dev_err(&client->dev, "writing to I2C_REG_CHANMASK failed");
220		return error;
221	}
222
223	error = i2c_smbus_write_byte_data(client, I2C_REG_IRQMASK,
224					  IRQ_PENTOUCH_TOUCHCONVDONE |
225						IRQ_PENRELEASE);
226	if (error) {
227		dev_err(&client->dev, "writing to I2C_REG_IRQMASK failed");
228		return error;
229	}
230
231	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH1,
232					  CONDIRQ | FILT_7SA);
233	if (error) {
234		dev_err(&client->dev, "writing to I2C_REG_TOUCH1 failed");
235		return error;
236	}
237
238	error = devm_request_threaded_irq(&client->dev, client->irq,
239					  NULL, sx8654_irq,
240					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
241					  client->name, sx8654);
242	if (error) {
243		dev_err(&client->dev,
244			"Failed to enable IRQ %d, error: %d\n",
245			client->irq, error);
246		return error;
247	}
248
249	/* Disable the IRQ, we'll enable it in sx8654_open() */
250	disable_irq(client->irq);
251
252	error = input_register_device(sx8654->input);
253	if (error)
254		return error;
255
256	i2c_set_clientdata(client, sx8654);
257	return 0;
258}
259
260#ifdef CONFIG_OF
261static const struct of_device_id sx8654_of_match[] = {
262	{ .compatible = "semtech,sx8654", },
263	{ },
264};
265MODULE_DEVICE_TABLE(of, sx8654_of_match);
266#endif
267
268static const struct i2c_device_id sx8654_id_table[] = {
269	{ "semtech_sx8654", 0 },
270	{ },
271};
272MODULE_DEVICE_TABLE(i2c, sx8654_id_table);
273
274static struct i2c_driver sx8654_driver = {
275	.driver = {
276		.name = "sx8654",
277		.of_match_table = of_match_ptr(sx8654_of_match),
278	},
279	.id_table = sx8654_id_table,
280	.probe = sx8654_probe,
281};
282module_i2c_driver(sx8654_driver);
283
284MODULE_AUTHOR("Sébastien Szymanski <sebastien.szymanski@armadeus.com>");
285MODULE_DESCRIPTION("Semtech SX8654 I2C Touchscreen Driver");
286MODULE_LICENSE("GPL");