1/*
2 * Driver for ADI Direct Digital Synthesis ad9850
3 *
4 * Copyright (c) 2010-2010 Analog Devices Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 */
11#include <linux/types.h>
12#include <linux/mutex.h>
13#include <linux/device.h>
14#include <linux/spi/spi.h>
15#include <linux/slab.h>
16#include <linux/sysfs.h>
17#include <linux/module.h>
18
19#include "../iio.h"
20#include "../sysfs.h"
21
22#define DRV_NAME "ad9850"
23
24#define value_mask (u16)0xf000
25#define addr_shift 12
26
27/* Register format: 4 bits addr + 12 bits value */
28struct ad9850_config {
29	u8 control[5];
30};
31
32struct ad9850_state {
33	struct mutex lock;
34	struct spi_device *sdev;
35};
36
37static ssize_t ad9850_set_parameter(struct device *dev,
38					struct device_attribute *attr,
39					const char *buf,
40					size_t len)
41{
42	struct spi_message msg;
43	struct spi_transfer xfer;
44	int ret;
45	struct ad9850_config *config = (struct ad9850_config *)buf;
46	struct iio_dev *idev = dev_get_drvdata(dev);
47	struct ad9850_state *st = iio_priv(idev);
48
49	xfer.len = len;
50	xfer.tx_buf = config;
51	mutex_lock(&st->lock);
52
53	spi_message_init(&msg);
54	spi_message_add_tail(&xfer, &msg);
55	ret = spi_sync(st->sdev, &msg);
56	if (ret)
57		goto error_ret;
58error_ret:
59	mutex_unlock(&st->lock);
60
61	return ret ? ret : len;
62}
63
64static IIO_DEVICE_ATTR(dds, S_IWUSR, NULL, ad9850_set_parameter, 0);
65
66static struct attribute *ad9850_attributes[] = {
67	&iio_dev_attr_dds.dev_attr.attr,
68	NULL,
69};
70
71static const struct attribute_group ad9850_attribute_group = {
72	.attrs = ad9850_attributes,
73};
74
75static const struct iio_info ad9850_info = {
76	.attrs = &ad9850_attribute_group,
77	.driver_module = THIS_MODULE,
78};
79
80static int __devinit ad9850_probe(struct spi_device *spi)
81{
82	struct ad9850_state *st;
83	struct iio_dev *idev;
84	int ret = 0;
85
86	idev = iio_allocate_device(sizeof(*st));
87	if (idev == NULL) {
88		ret = -ENOMEM;
89		goto error_ret;
90	}
91	spi_set_drvdata(spi, idev);
92	st = iio_priv(idev);
93	mutex_init(&st->lock);
94	st->sdev = spi;
95
96	idev->dev.parent = &spi->dev;
97	idev->info = &ad9850_info;
98	idev->modes = INDIO_DIRECT_MODE;
99
100	ret = iio_device_register(idev);
101	if (ret)
102		goto error_free_dev;
103	spi->max_speed_hz = 2000000;
104	spi->mode = SPI_MODE_3;
105	spi->bits_per_word = 16;
106	spi_setup(spi);
107
108	return 0;
109
110error_free_dev:
111	iio_free_device(idev);
112error_ret:
113	return ret;
114}
115
116static int __devexit ad9850_remove(struct spi_device *spi)
117{
118	iio_device_unregister(spi_get_drvdata(spi));
119	iio_free_device(spi_get_drvdata(spi));
120
121	return 0;
122}
123
124static struct spi_driver ad9850_driver = {
125	.driver = {
126		.name = DRV_NAME,
127		.owner = THIS_MODULE,
128	},
129	.probe = ad9850_probe,
130	.remove = __devexit_p(ad9850_remove),
131};
132module_spi_driver(ad9850_driver);
133
134MODULE_AUTHOR("Cliff Cai");
135MODULE_DESCRIPTION("Analog Devices ad9850 driver");
136MODULE_LICENSE("GPL v2");
137MODULE_ALIAS("spi:" DRV_NAME);
138