1/*
2 * AD714X CapTouch Programmable Controller driver (SPI bus)
3 *
4 * Copyright 2009-2011 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8
9#include <linux/input.h>	/* BUS_SPI */
10#include <linux/module.h>
11#include <linux/spi/spi.h>
12#include <linux/pm.h>
13#include <linux/types.h>
14#include "ad714x.h"
15
16#define AD714x_SPI_CMD_PREFIX      0xE000   /* bits 15:11 */
17#define AD714x_SPI_READ            BIT(10)
18
19static int __maybe_unused ad714x_spi_suspend(struct device *dev)
20{
21	return ad714x_disable(spi_get_drvdata(to_spi_device(dev)));
22}
23
24static int __maybe_unused ad714x_spi_resume(struct device *dev)
25{
26	return ad714x_enable(spi_get_drvdata(to_spi_device(dev)));
27}
28
29static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume);
30
31static int ad714x_spi_read(struct ad714x_chip *chip,
32			   unsigned short reg, unsigned short *data, size_t len)
33{
34	struct spi_device *spi = to_spi_device(chip->dev);
35	struct spi_message message;
36	struct spi_transfer xfer[2];
37	int i;
38	int error;
39
40	spi_message_init(&message);
41	memset(xfer, 0, sizeof(xfer));
42
43	chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX |
44					AD714x_SPI_READ | reg);
45	xfer[0].tx_buf = &chip->xfer_buf[0];
46	xfer[0].len = sizeof(chip->xfer_buf[0]);
47	spi_message_add_tail(&xfer[0], &message);
48
49	xfer[1].rx_buf = &chip->xfer_buf[1];
50	xfer[1].len = sizeof(chip->xfer_buf[1]) * len;
51	spi_message_add_tail(&xfer[1], &message);
52
53	error = spi_sync(spi, &message);
54	if (unlikely(error)) {
55		dev_err(chip->dev, "SPI read error: %d\n", error);
56		return error;
57	}
58
59	for (i = 0; i < len; i++)
60		data[i] = be16_to_cpu(chip->xfer_buf[i + 1]);
61
62	return 0;
63}
64
65static int ad714x_spi_write(struct ad714x_chip *chip,
66			    unsigned short reg, unsigned short data)
67{
68	struct spi_device *spi = to_spi_device(chip->dev);
69	int error;
70
71	chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | reg);
72	chip->xfer_buf[1] = cpu_to_be16(data);
73
74	error = spi_write(spi, (u8 *)chip->xfer_buf,
75			  2 * sizeof(*chip->xfer_buf));
76	if (unlikely(error)) {
77		dev_err(chip->dev, "SPI write error: %d\n", error);
78		return error;
79	}
80
81	return 0;
82}
83
84static int ad714x_spi_probe(struct spi_device *spi)
85{
86	struct ad714x_chip *chip;
87	int err;
88
89	spi->bits_per_word = 8;
90	err = spi_setup(spi);
91	if (err < 0)
92		return err;
93
94	chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq,
95			    ad714x_spi_read, ad714x_spi_write);
96	if (IS_ERR(chip))
97		return PTR_ERR(chip);
98
99	spi_set_drvdata(spi, chip);
100
101	return 0;
102}
103
104static int ad714x_spi_remove(struct spi_device *spi)
105{
106	struct ad714x_chip *chip = spi_get_drvdata(spi);
107
108	ad714x_remove(chip);
109
110	return 0;
111}
112
113static struct spi_driver ad714x_spi_driver = {
114	.driver = {
115		.name	= "ad714x_captouch",
116		.owner	= THIS_MODULE,
117		.pm	= &ad714x_spi_pm,
118	},
119	.probe		= ad714x_spi_probe,
120	.remove		= ad714x_spi_remove,
121};
122
123module_spi_driver(ad714x_spi_driver);
124
125MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver");
126MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
127MODULE_LICENSE("GPL");
128