1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Touch Screen driver for Renesas MIGO-R Platform
4 *
5 * Copyright (c) 2008 Magnus Damm
6 * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>,
7 *  Kenati Technologies Pvt Ltd.
8 */
9#include <linux/module.h>
10#include <linux/kernel.h>
11#include <linux/input.h>
12#include <linux/interrupt.h>
13#include <linux/pm.h>
14#include <linux/slab.h>
15#include <asm/io.h>
16#include <linux/i2c.h>
17#include <linux/timer.h>
18
19#define EVENT_PENDOWN 1
20#define EVENT_REPEAT  2
21#define EVENT_PENUP   3
22
23struct migor_ts_priv {
24	struct i2c_client *client;
25	struct input_dev *input;
26	int irq;
27};
28
29static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11,
30					       0x01, 0x06, 0x07, };
31static const u_int8_t migor_ts_dis_seq[17] = { };
32
33static irqreturn_t migor_ts_isr(int irq, void *dev_id)
34{
35	struct migor_ts_priv *priv = dev_id;
36	unsigned short xpos, ypos;
37	unsigned char event;
38	u_int8_t buf[16];
39
40	/*
41	 * The touch screen controller chip is hooked up to the CPU
42	 * using I2C and a single interrupt line. The interrupt line
43	 * is pulled low whenever someone taps the screen. To deassert
44	 * the interrupt line we need to acknowledge the interrupt by
45	 * communicating with the controller over the slow i2c bus.
46	 *
47	 * Since I2C bus controller may sleep we are using threaded
48	 * IRQ here.
49	 */
50
51	memset(buf, 0, sizeof(buf));
52
53	/* Set Index 0 */
54	buf[0] = 0;
55	if (i2c_master_send(priv->client, buf, 1) != 1) {
56		dev_err(&priv->client->dev, "Unable to write i2c index\n");
57		goto out;
58	}
59
60	/* Now do Page Read */
61	if (i2c_master_recv(priv->client, buf, sizeof(buf)) != sizeof(buf)) {
62		dev_err(&priv->client->dev, "Unable to read i2c page\n");
63		goto out;
64	}
65
66	ypos = ((buf[9] & 0x03) << 8 | buf[8]);
67	xpos = ((buf[11] & 0x03) << 8 | buf[10]);
68	event = buf[12];
69
70	switch (event) {
71	case EVENT_PENDOWN:
72	case EVENT_REPEAT:
73		input_report_key(priv->input, BTN_TOUCH, 1);
74		input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/
75		input_report_abs(priv->input, ABS_Y, xpos);
76		input_sync(priv->input);
77		break;
78
79	case EVENT_PENUP:
80		input_report_key(priv->input, BTN_TOUCH, 0);
81		input_sync(priv->input);
82		break;
83	}
84
85 out:
86	return IRQ_HANDLED;
87}
88
89static int migor_ts_open(struct input_dev *dev)
90{
91	struct migor_ts_priv *priv = input_get_drvdata(dev);
92	struct i2c_client *client = priv->client;
93	int count;
94
95	/* enable controller */
96	count = i2c_master_send(client, migor_ts_ena_seq,
97				sizeof(migor_ts_ena_seq));
98	if (count != sizeof(migor_ts_ena_seq)) {
99		dev_err(&client->dev, "Unable to enable touchscreen.\n");
100		return -ENXIO;
101	}
102
103	return 0;
104}
105
106static void migor_ts_close(struct input_dev *dev)
107{
108	struct migor_ts_priv *priv = input_get_drvdata(dev);
109	struct i2c_client *client = priv->client;
110
111	disable_irq(priv->irq);
112
113	/* disable controller */
114	i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq));
115
116	enable_irq(priv->irq);
117}
118
119static int migor_ts_probe(struct i2c_client *client)
120{
121	struct migor_ts_priv *priv;
122	struct input_dev *input;
123	int error;
124
125	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
126	input = input_allocate_device();
127	if (!priv || !input) {
128		dev_err(&client->dev, "failed to allocate memory\n");
129		error = -ENOMEM;
130		goto err_free_mem;
131	}
132
133	priv->client = client;
134	priv->input = input;
135	priv->irq = client->irq;
136
137	input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
138
139	__set_bit(BTN_TOUCH, input->keybit);
140
141	input_set_abs_params(input, ABS_X, 95, 955, 0, 0);
142	input_set_abs_params(input, ABS_Y, 85, 935, 0, 0);
143
144	input->name = client->name;
145	input->id.bustype = BUS_I2C;
146	input->dev.parent = &client->dev;
147
148	input->open = migor_ts_open;
149	input->close = migor_ts_close;
150
151	input_set_drvdata(input, priv);
152
153	error = request_threaded_irq(priv->irq, NULL, migor_ts_isr,
154                                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
155                                     client->name, priv);
156	if (error) {
157		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
158		goto err_free_mem;
159	}
160
161	error = input_register_device(input);
162	if (error)
163		goto err_free_irq;
164
165	i2c_set_clientdata(client, priv);
166	device_init_wakeup(&client->dev, 1);
167
168	return 0;
169
170 err_free_irq:
171	free_irq(priv->irq, priv);
172 err_free_mem:
173	input_free_device(input);
174	kfree(priv);
175	return error;
176}
177
178static void migor_ts_remove(struct i2c_client *client)
179{
180	struct migor_ts_priv *priv = i2c_get_clientdata(client);
181
182	free_irq(priv->irq, priv);
183	input_unregister_device(priv->input);
184	kfree(priv);
185
186	dev_set_drvdata(&client->dev, NULL);
187}
188
189static int migor_ts_suspend(struct device *dev)
190{
191	struct i2c_client *client = to_i2c_client(dev);
192	struct migor_ts_priv *priv = i2c_get_clientdata(client);
193
194	if (device_may_wakeup(&client->dev))
195		enable_irq_wake(priv->irq);
196
197	return 0;
198}
199
200static int migor_ts_resume(struct device *dev)
201{
202	struct i2c_client *client = to_i2c_client(dev);
203	struct migor_ts_priv *priv = i2c_get_clientdata(client);
204
205	if (device_may_wakeup(&client->dev))
206		disable_irq_wake(priv->irq);
207
208	return 0;
209}
210
211static DEFINE_SIMPLE_DEV_PM_OPS(migor_ts_pm, migor_ts_suspend, migor_ts_resume);
212
213static const struct i2c_device_id migor_ts_id[] = {
214	{ "migor_ts", 0 },
215	{ }
216};
217MODULE_DEVICE_TABLE(i2c, migor_ts_id);
218
219static struct i2c_driver migor_ts_driver = {
220	.driver = {
221		.name = "migor_ts",
222		.pm = pm_sleep_ptr(&migor_ts_pm),
223	},
224	.probe = migor_ts_probe,
225	.remove = migor_ts_remove,
226	.id_table = migor_ts_id,
227};
228
229module_i2c_driver(migor_ts_driver);
230
231MODULE_DESCRIPTION("MigoR Touchscreen driver");
232MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
233MODULE_LICENSE("GPL");
234