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 {
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 
178 static 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 
189 static 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 
200 static 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 
211 static DEFINE_SIMPLE_DEV_PM_OPS(migor_ts_pm, migor_ts_suspend, migor_ts_resume);
212 
213 static const struct i2c_device_id migor_ts_id[] = {
214 	{ "migor_ts", 0 },
215 	{ }
216 };
217 MODULE_DEVICE_TABLE(i2c, migor_ts_id);
218 
219 static 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 
229 module_i2c_driver(migor_ts_driver);
230 
231 MODULE_DESCRIPTION("MigoR Touchscreen driver");
232 MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
233 MODULE_LICENSE("GPL");
234