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 
23 struct migor_ts_priv {
24 	struct i2c_client *client;
25 	struct input_dev *input;
26 	int irq;
27 };
28 
29 static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11,
30 					       0x01, 0x06, 0x07, };
31 static const u_int8_t migor_ts_dis_seq[17] = { };
32 
33 static 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 
89 static 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 
106 static 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 
119 static int migor_ts_probe(struct i2c_client *client,
120 			  const struct i2c_device_id *idp)
121 {
122 	struct migor_ts_priv *priv;
123 	struct input_dev *input;
124 	int error;
125 
126 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
127 	input = input_allocate_device();
128 	if (!priv || !input) {
129 		dev_err(&client->dev, "failed to allocate memory\n");
130 		error = -ENOMEM;
131 		goto err_free_mem;
132 	}
133 
134 	priv->client = client;
135 	priv->input = input;
136 	priv->irq = client->irq;
137 
138 	input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
139 
140 	__set_bit(BTN_TOUCH, input->keybit);
141 
142 	input_set_abs_params(input, ABS_X, 95, 955, 0, 0);
143 	input_set_abs_params(input, ABS_Y, 85, 935, 0, 0);
144 
145 	input->name = client->name;
146 	input->id.bustype = BUS_I2C;
147 	input->dev.parent = &client->dev;
148 
149 	input->open = migor_ts_open;
150 	input->close = migor_ts_close;
151 
152 	input_set_drvdata(input, priv);
153 
154 	error = request_threaded_irq(priv->irq, NULL, migor_ts_isr,
155                                      IRQF_TRIGGER_LOW | IRQF_ONESHOT,
156                                      client->name, priv);
157 	if (error) {
158 		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
159 		goto err_free_mem;
160 	}
161 
162 	error = input_register_device(input);
163 	if (error)
164 		goto err_free_irq;
165 
166 	i2c_set_clientdata(client, priv);
167 	device_init_wakeup(&client->dev, 1);
168 
169 	return 0;
170 
171  err_free_irq:
172 	free_irq(priv->irq, priv);
173  err_free_mem:
174 	input_free_device(input);
175 	kfree(priv);
176 	return error;
177 }
178 
179 static int migor_ts_remove(struct i2c_client *client)
180 {
181 	struct migor_ts_priv *priv = i2c_get_clientdata(client);
182 
183 	free_irq(priv->irq, priv);
184 	input_unregister_device(priv->input);
185 	kfree(priv);
186 
187 	dev_set_drvdata(&client->dev, NULL);
188 
189 	return 0;
190 }
191 
192 static int __maybe_unused migor_ts_suspend(struct device *dev)
193 {
194 	struct i2c_client *client = to_i2c_client(dev);
195 	struct migor_ts_priv *priv = i2c_get_clientdata(client);
196 
197 	if (device_may_wakeup(&client->dev))
198 		enable_irq_wake(priv->irq);
199 
200 	return 0;
201 }
202 
203 static int __maybe_unused migor_ts_resume(struct device *dev)
204 {
205 	struct i2c_client *client = to_i2c_client(dev);
206 	struct migor_ts_priv *priv = i2c_get_clientdata(client);
207 
208 	if (device_may_wakeup(&client->dev))
209 		disable_irq_wake(priv->irq);
210 
211 	return 0;
212 }
213 
214 static SIMPLE_DEV_PM_OPS(migor_ts_pm, migor_ts_suspend, migor_ts_resume);
215 
216 static const struct i2c_device_id migor_ts_id[] = {
217 	{ "migor_ts", 0 },
218 	{ }
219 };
220 MODULE_DEVICE_TABLE(i2c, migor_ts_id);
221 
222 static struct i2c_driver migor_ts_driver = {
223 	.driver = {
224 		.name = "migor_ts",
225 		.pm = &migor_ts_pm,
226 	},
227 	.probe = migor_ts_probe,
228 	.remove = migor_ts_remove,
229 	.id_table = migor_ts_id,
230 };
231 
232 module_i2c_driver(migor_ts_driver);
233 
234 MODULE_DESCRIPTION("MigoR Touchscreen driver");
235 MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
236 MODULE_LICENSE("GPL");
237