summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/migor_ts.c
blob: 504ca11749a1896e35b489bfba4bdc6747c57e71 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
/*
 * Touch Screen driver for Renesas MIGO-R Platform
 *
 * Copyright (c) 2008 Magnus Damm
 * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>,
 *  Kenati Technologies Pvt Ltd.
 *
 * 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/interrupt.h>
#include <asm/io.h>
#include <linux/i2c.h>
#include <linux/timer.h>

#define EVENT_PENDOWN 1
#define EVENT_REPEAT  2
#define EVENT_PENUP   3

struct migor_ts_priv {
	struct i2c_client *client;
	struct input_dev *input;
	struct delayed_work work;
	int irq;
};

static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11,
					       0x01, 0x06, 0x07, };
static const u_int8_t migor_ts_dis_seq[17] = { };

static void migor_ts_poscheck(struct work_struct *work)
{
	struct migor_ts_priv *priv = container_of(work,
						  struct migor_ts_priv,
						  work.work);
	unsigned short xpos, ypos;
	unsigned char event;
	u_int8_t buf[16];

	memset(buf, 0, sizeof(buf));

	/* Set Index 0 */
	buf[0] = 0;
	if (i2c_master_send(priv->client, buf, 1) != 1) {
		dev_err(&priv->client->dev, "Unable to write i2c index\n");
		goto out;
	}

	/* Now do Page Read */
	if (i2c_master_recv(priv->client, buf, sizeof(buf)) != sizeof(buf)) {
		dev_err(&priv->client->dev, "Unable to read i2c page\n");
		goto out;
	}

	ypos = ((buf[9] & 0x03) << 8 | buf[8]);
	xpos = ((buf[11] & 0x03) << 8 | buf[10]);
	event = buf[12];

	if (event == EVENT_PENDOWN || event == EVENT_REPEAT) {
		input_report_key(priv->input, BTN_TOUCH, 1);
		input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/
		input_report_abs(priv->input, ABS_Y, xpos);
		input_sync(priv->input);
	} else if (event == EVENT_PENUP) {
		input_report_key(priv->input, BTN_TOUCH, 0);
		input_sync(priv->input);
	}
 out:
	enable_irq(priv->irq);
}

static irqreturn_t migor_ts_isr(int irq, void *dev_id)
{
	struct migor_ts_priv *priv = dev_id;

	/* the touch screen controller chip is hooked up to the cpu
	 * using i2c and a single interrupt line. the interrupt line
	 * is pulled low whenever someone taps the screen. to deassert
	 * the interrupt line we need to acknowledge the interrupt by
	 * communicating with the controller over the slow i2c bus.
	 *
	 * we can't acknowledge from interrupt context since the i2c
	 * bus controller may sleep, so we just disable the interrupt
	 * here and handle the acknowledge using delayed work.
	 */

	disable_irq_nosync(irq);
	schedule_delayed_work(&priv->work, HZ / 20);

	return IRQ_HANDLED;
}


static int migor_ts_open(struct input_dev *dev)
{
	struct migor_ts_priv *priv = input_get_drvdata(dev);
	struct i2c_client *client = priv->client;
	int count;

	/* enable controller */
	count = i2c_master_send(client, migor_ts_ena_seq,
				sizeof(migor_ts_ena_seq));
	if (count != sizeof(migor_ts_ena_seq)) {
		dev_err(&client->dev, "Unable to enable touchscreen.\n");
		return -ENXIO;
	}

	return 0;
}

static void migor_ts_close(struct input_dev *dev)
{
	struct migor_ts_priv *priv = input_get_drvdata(dev);
	struct i2c_client *client = priv->client;

	disable_irq(priv->irq);

	/* cancel pending work and wait for migor_ts_poscheck() to finish */
	if (cancel_delayed_work_sync(&priv->work)) {
		/*
		 * if migor_ts_poscheck was canceled we need to enable IRQ
		 * here to balance disable done in migor_ts_isr.
		 */
		enable_irq(priv->irq);
	}

	/* disable controller */
	i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq));

	enable_irq(priv->irq);
}

static int migor_ts_probe(struct i2c_client *client,
			  const struct i2c_device_id *idp)
{
	struct migor_ts_priv *priv;
	struct input_dev *input;
	int error;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		dev_err(&client->dev, "failed to allocate driver data\n");
		error = -ENOMEM;
		goto err0;
	}

	dev_set_drvdata(&client->dev, priv);

	input = input_allocate_device();
	if (!input) {
		dev_err(&client->dev, "Failed to allocate input device.\n");
		error = -ENOMEM;
		goto err1;
	}

	input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	input_set_abs_params(input, ABS_X, 95, 955, 0, 0);
	input_set_abs_params(input, ABS_Y, 85, 935, 0, 0);

	input->name = client->name;
	input->id.bustype = BUS_I2C;
	input->dev.parent = &client->dev;

	input->open = migor_ts_open;
	input->close = migor_ts_close;

	input_set_drvdata(input, priv);

	priv->client = client;
	priv->input = input;
	INIT_DELAYED_WORK(&priv->work, migor_ts_poscheck);
	priv->irq = client->irq;

	error = input_register_device(input);
	if (error)
		goto err1;

	error = request_irq(priv->irq, migor_ts_isr, IRQF_TRIGGER_LOW,
			    client->name, priv);
	if (error) {
		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
		goto err2;
	}

	return 0;

 err2:
	input_unregister_device(input);
	input = NULL; /* so we dont try to free it below */
 err1:
	input_free_device(input);
	kfree(priv);
 err0:
	dev_set_drvdata(&client->dev, NULL);
	return error;
}

static int migor_ts_remove(struct i2c_client *client)
{
	struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);

	free_irq(priv->irq, priv);
	input_unregister_device(priv->input);
	kfree(priv);

	dev_set_drvdata(&client->dev, NULL);

	return 0;
}

static const struct i2c_device_id migor_ts_id[] = {
	{ "migor_ts", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, migor_ts);

static struct i2c_driver migor_ts_driver = {
	.driver = {
		.name = "migor_ts",
	},
	.probe = migor_ts_probe,
	.remove = migor_ts_remove,
	.id_table = migor_ts_id,
};

static int __init migor_ts_init(void)
{
	return i2c_add_driver(&migor_ts_driver);
}

static void __exit migor_ts_exit(void)
{
	i2c_del_driver(&migor_ts_driver);
}

MODULE_DESCRIPTION("MigoR Touchscreen driver");
MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
MODULE_LICENSE("GPL");

module_init(migor_ts_init);
module_exit(migor_ts_exit);