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 <linux/iio/iio.h>
20 #include <linux/iio/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 */
28 struct ad9850_config {
29 u8 control[5];
30 };
31
32 struct ad9850_state {
33 struct mutex lock;
34 struct spi_device *sdev;
35 };
36
ad9850_set_parameter(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)37 static 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_transfer xfer;
43 int ret;
44 struct ad9850_config *config = (struct ad9850_config *)buf;
45 struct iio_dev *idev = dev_to_iio_dev(dev);
46 struct ad9850_state *st = iio_priv(idev);
47
48 xfer.len = len;
49 xfer.tx_buf = config;
50 mutex_lock(&st->lock);
51
52 ret = spi_sync_transfer(st->sdev, &xfer, 1);
53 if (ret)
54 goto error_ret;
55 error_ret:
56 mutex_unlock(&st->lock);
57
58 return ret ? ret : len;
59 }
60
61 static IIO_DEVICE_ATTR(dds, S_IWUSR, NULL, ad9850_set_parameter, 0);
62
63 static struct attribute *ad9850_attributes[] = {
64 &iio_dev_attr_dds.dev_attr.attr,
65 NULL,
66 };
67
68 static const struct attribute_group ad9850_attribute_group = {
69 .attrs = ad9850_attributes,
70 };
71
72 static const struct iio_info ad9850_info = {
73 .attrs = &ad9850_attribute_group,
74 .driver_module = THIS_MODULE,
75 };
76
ad9850_probe(struct spi_device * spi)77 static int ad9850_probe(struct spi_device *spi)
78 {
79 struct ad9850_state *st;
80 struct iio_dev *idev;
81 int ret = 0;
82
83 idev = iio_device_alloc(sizeof(*st));
84 if (idev == NULL) {
85 ret = -ENOMEM;
86 goto error_ret;
87 }
88 spi_set_drvdata(spi, idev);
89 st = iio_priv(idev);
90 mutex_init(&st->lock);
91 st->sdev = spi;
92
93 idev->dev.parent = &spi->dev;
94 idev->info = &ad9850_info;
95 idev->modes = INDIO_DIRECT_MODE;
96
97 ret = iio_device_register(idev);
98 if (ret)
99 goto error_free_dev;
100 spi->max_speed_hz = 2000000;
101 spi->mode = SPI_MODE_3;
102 spi->bits_per_word = 16;
103 spi_setup(spi);
104
105 return 0;
106
107 error_free_dev:
108 iio_device_free(idev);
109 error_ret:
110 return ret;
111 }
112
ad9850_remove(struct spi_device * spi)113 static int ad9850_remove(struct spi_device *spi)
114 {
115 iio_device_unregister(spi_get_drvdata(spi));
116 iio_device_free(spi_get_drvdata(spi));
117
118 return 0;
119 }
120
121 static struct spi_driver ad9850_driver = {
122 .driver = {
123 .name = DRV_NAME,
124 .owner = THIS_MODULE,
125 },
126 .probe = ad9850_probe,
127 .remove = ad9850_remove,
128 };
129 module_spi_driver(ad9850_driver);
130
131 MODULE_AUTHOR("Cliff Cai");
132 MODULE_DESCRIPTION("Analog Devices ad9850 driver");
133 MODULE_LICENSE("GPL v2");
134 MODULE_ALIAS("spi:" DRV_NAME);
135