summaryrefslogtreecommitdiffstats
path: root/drivers/input/keyboard/lm8333.c
blob: ca168a6679deea0ada4cccf6cc48b3f40a3ce9b0 (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
/*
 * LM8333 keypad driver
 * Copyright (C) 2012 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
 *
 * This program 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.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/input/matrix_keypad.h>
#include <linux/input/lm8333.h>

#define LM8333_FIFO_READ		0x20
#define LM8333_DEBOUNCE			0x22
#define LM8333_READ_INT			0xD0
#define LM8333_ACTIVE			0xE4
#define LM8333_READ_ERROR		0xF0

#define LM8333_KEYPAD_IRQ		(1 << 0)
#define LM8333_ERROR_IRQ		(1 << 3)

#define LM8333_ERROR_KEYOVR		0x04
#define LM8333_ERROR_FIFOOVR		0x40

#define LM8333_FIFO_TRANSFER_SIZE	16

#define LM8333_NUM_ROWS		8
#define LM8333_NUM_COLS		16
#define LM8333_ROW_SHIFT	4

struct lm8333 {
	struct i2c_client *client;
	struct input_dev *input;
	unsigned short keycodes[LM8333_NUM_ROWS << LM8333_ROW_SHIFT];
};

/* The accessors try twice because the first access may be needed for wakeup */
#define LM8333_READ_RETRIES 2

int lm8333_read8(struct lm8333 *lm8333, u8 cmd)
{
	int retries = 0, ret;

	do {
		ret = i2c_smbus_read_byte_data(lm8333->client, cmd);
	} while (ret < 0 && retries++ < LM8333_READ_RETRIES);

	return ret;
}

int lm8333_write8(struct lm8333 *lm8333, u8 cmd, u8 val)
{
	int retries = 0, ret;

	do {
		ret = i2c_smbus_write_byte_data(lm8333->client, cmd, val);
	} while (ret < 0 && retries++ < LM8333_READ_RETRIES);

	return ret;
}

int lm8333_read_block(struct lm8333 *lm8333, u8 cmd, u8 len, u8 *buf)
{
	int retries = 0, ret;

	do {
		ret = i2c_smbus_read_i2c_block_data(lm8333->client,
						    cmd, len, buf);
	} while (ret < 0 && retries++ < LM8333_READ_RETRIES);

	return ret;
}

static void lm8333_key_handler(struct lm8333 *lm8333)
{
	struct input_dev *input = lm8333->input;
	u8 keys[LM8333_FIFO_TRANSFER_SIZE];
	u8 code, pressed;
	int i, ret;

	ret = lm8333_read_block(lm8333, LM8333_FIFO_READ,
				LM8333_FIFO_TRANSFER_SIZE, keys);
	if (ret != LM8333_FIFO_TRANSFER_SIZE) {
		dev_err(&lm8333->client->dev,
			"Error %d while reading FIFO\n", ret);
		return;
	}

	for (i = 0; keys[i] && i < LM8333_FIFO_TRANSFER_SIZE; i++) {
		pressed = keys[i] & 0x80;
		code = keys[i] & 0x7f;

		input_event(input, EV_MSC, MSC_SCAN, code);
		input_report_key(input, lm8333->keycodes[code], pressed);
	}

	input_sync(input);
}

static irqreturn_t lm8333_irq_thread(int irq, void *data)
{
	struct lm8333 *lm8333 = data;
	u8 status = lm8333_read8(lm8333, LM8333_READ_INT);

	if (!status)
		return IRQ_NONE;

	if (status & LM8333_ERROR_IRQ) {
		u8 err = lm8333_read8(lm8333, LM8333_READ_ERROR);

		if (err & (LM8333_ERROR_KEYOVR | LM8333_ERROR_FIFOOVR)) {
			u8 dummy[LM8333_FIFO_TRANSFER_SIZE];

			lm8333_read_block(lm8333, LM8333_FIFO_READ,
					LM8333_FIFO_TRANSFER_SIZE, dummy);
		}
		dev_err(&lm8333->client->dev, "Got error %02x\n", err);
	}

	if (status & LM8333_KEYPAD_IRQ)
		lm8333_key_handler(lm8333);

	return IRQ_HANDLED;
}

static int __devinit lm8333_probe(struct i2c_client *client,
				  const struct i2c_device_id *id)
{
	const struct lm8333_platform_data *pdata = client->dev.platform_data;
	struct lm8333 *lm8333;
	struct input_dev *input;
	int err, active_time;

	if (!pdata)
		return -EINVAL;

	active_time = pdata->active_time ?: 500;
	if (active_time / 3 <= pdata->debounce_time / 3) {
		dev_err(&client->dev, "Active time not big enough!\n");
		return -EINVAL;
	}

	lm8333 = kzalloc(sizeof(*lm8333), GFP_KERNEL);
	input = input_allocate_device();
	if (!lm8333 || !input) {
		err = -ENOMEM;
		goto free_mem;
	}

	lm8333->client = client;
	lm8333->input = input;

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

	input_set_capability(input, EV_MSC, MSC_SCAN);

	err = matrix_keypad_build_keymap(pdata->matrix_data, NULL,
					 LM8333_NUM_ROWS, LM8333_NUM_COLS,
					 lm8333->keycodes, input);
	if (err)
		goto free_mem;

	if (pdata->debounce_time) {
		err = lm8333_write8(lm8333, LM8333_DEBOUNCE,
				    pdata->debounce_time / 3);
		if (err)
			dev_warn(&client->dev, "Unable to set debounce time\n");
	}

	if (pdata->active_time) {
		err = lm8333_write8(lm8333, LM8333_ACTIVE,
				    pdata->active_time / 3);
		if (err)
			dev_warn(&client->dev, "Unable to set active time\n");
	}

	err = request_threaded_irq(client->irq, NULL, lm8333_irq_thread,
				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
				   "lm8333", lm8333);
	if (err)
		goto free_mem;

	err = input_register_device(input);
	if (err)
		goto free_irq;

	i2c_set_clientdata(client, lm8333);
	return 0;

 free_irq:
	free_irq(client->irq, lm8333);
 free_mem:
	input_free_device(input);
	kfree(lm8333);
	return err;
}

static int __devexit lm8333_remove(struct i2c_client *client)
{
	struct lm8333 *lm8333 = i2c_get_clientdata(client);

	free_irq(client->irq, lm8333);
	input_unregister_device(lm8333->input);
	kfree(lm8333);

	return 0;
}

static const struct i2c_device_id lm8333_id[] = {
	{ "lm8333", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lm8333_id);

static struct i2c_driver lm8333_driver = {
	.driver = {
		.name		= "lm8333",
		.owner		= THIS_MODULE,
	},
	.probe		= lm8333_probe,
	.remove		= __devexit_p(lm8333_remove),
	.id_table	= lm8333_id,
};
module_i2c_driver(lm8333_driver);

MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
MODULE_DESCRIPTION("LM8333 keyboard driver");
MODULE_LICENSE("GPL v2");
OpenPOWER on IntegriCloud