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
|
/*
* AD714X CapTouch Programmable Controller driver (SPI bus)
*
* Copyright 2009-2011 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <linux/input.h> /* BUS_SPI */
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/pm.h>
#include <linux/types.h>
#include "ad714x.h"
#define AD714x_SPI_CMD_PREFIX 0xE000 /* bits 15:11 */
#define AD714x_SPI_READ BIT(10)
#ifdef CONFIG_PM
static int ad714x_spi_suspend(struct device *dev)
{
return ad714x_disable(spi_get_drvdata(to_spi_device(dev)));
}
static int ad714x_spi_resume(struct device *dev)
{
return ad714x_enable(spi_get_drvdata(to_spi_device(dev)));
}
#endif
static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume);
static int ad714x_spi_read(struct ad714x_chip *chip,
unsigned short reg, unsigned short *data, size_t len)
{
struct spi_device *spi = to_spi_device(chip->dev);
struct spi_message message;
struct spi_transfer xfer[2];
int i;
int error;
spi_message_init(&message);
memset(xfer, 0, sizeof(xfer));
chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX |
AD714x_SPI_READ | reg);
xfer[0].tx_buf = &chip->xfer_buf[0];
xfer[0].len = sizeof(chip->xfer_buf[0]);
spi_message_add_tail(&xfer[0], &message);
xfer[1].rx_buf = &chip->xfer_buf[1];
xfer[1].len = sizeof(chip->xfer_buf[1]) * len;
spi_message_add_tail(&xfer[1], &message);
error = spi_sync(spi, &message);
if (unlikely(error)) {
dev_err(chip->dev, "SPI read error: %d\n", error);
return error;
}
for (i = 0; i < len; i++)
data[i] = be16_to_cpu(chip->xfer_buf[i + 1]);
return 0;
}
static int ad714x_spi_write(struct ad714x_chip *chip,
unsigned short reg, unsigned short data)
{
struct spi_device *spi = to_spi_device(chip->dev);
int error;
chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | reg);
chip->xfer_buf[1] = cpu_to_be16(data);
error = spi_write(spi, (u8 *)chip->xfer_buf,
2 * sizeof(*chip->xfer_buf));
if (unlikely(error)) {
dev_err(chip->dev, "SPI write error: %d\n", error);
return error;
}
return 0;
}
static int __devinit ad714x_spi_probe(struct spi_device *spi)
{
struct ad714x_chip *chip;
int err;
spi->bits_per_word = 8;
err = spi_setup(spi);
if (err < 0)
return err;
chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq,
ad714x_spi_read, ad714x_spi_write);
if (IS_ERR(chip))
return PTR_ERR(chip);
spi_set_drvdata(spi, chip);
return 0;
}
static int __devexit ad714x_spi_remove(struct spi_device *spi)
{
struct ad714x_chip *chip = spi_get_drvdata(spi);
ad714x_remove(chip);
spi_set_drvdata(spi, NULL);
return 0;
}
static struct spi_driver ad714x_spi_driver = {
.driver = {
.name = "ad714x_captouch",
.owner = THIS_MODULE,
.pm = &ad714x_spi_pm,
},
.probe = ad714x_spi_probe,
.remove = ad714x_spi_remove,
};
module_spi_driver(ad714x_spi_driver);
MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver");
MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_LICENSE("GPL");
|
