1 /*
2 * Driver for ADI Direct Digital Synthesis ad5930
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 "ad5930"
23
24 #define value_mask (u16)0xf000
25 #define addr_shift 12
26
27 /* Register format: 4 bits addr + 12 bits value */
28 struct ad5903_config {
29 u16 control;
30 u16 incnum;
31 u16 frqdelt[2];
32 u16 incitvl;
33 u16 buritvl;
34 u16 strtfrq[2];
35 };
36
37 struct ad5930_state {
38 struct mutex lock;
39 struct spi_device *sdev;
40 };
41
ad5930_set_parameter(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)42 static ssize_t ad5930_set_parameter(struct device *dev,
43 struct device_attribute *attr,
44 const char *buf,
45 size_t len)
46 {
47 struct spi_transfer xfer;
48 int ret;
49 struct ad5903_config *config = (struct ad5903_config *)buf;
50 struct iio_dev *idev = dev_to_iio_dev(dev);
51 struct ad5930_state *st = iio_priv(idev);
52
53 config->control = (config->control & ~value_mask);
54 config->incnum = (config->control & ~value_mask) | (1 << addr_shift);
55 config->frqdelt[0] = (config->control & ~value_mask) | (2 << addr_shift);
56 config->frqdelt[1] = (config->control & ~value_mask) | 3 << addr_shift;
57 config->incitvl = (config->control & ~value_mask) | 4 << addr_shift;
58 config->buritvl = (config->control & ~value_mask) | 8 << addr_shift;
59 config->strtfrq[0] = (config->control & ~value_mask) | 0xc << addr_shift;
60 config->strtfrq[1] = (config->control & ~value_mask) | 0xd << addr_shift;
61
62 xfer.len = len;
63 xfer.tx_buf = config;
64 mutex_lock(&st->lock);
65
66 ret = spi_sync_transfer(st->sdev, &xfer, 1);
67 if (ret)
68 goto error_ret;
69 error_ret:
70 mutex_unlock(&st->lock);
71
72 return ret ? ret : len;
73 }
74
75 static IIO_DEVICE_ATTR(dds, S_IWUSR, NULL, ad5930_set_parameter, 0);
76
77 static struct attribute *ad5930_attributes[] = {
78 &iio_dev_attr_dds.dev_attr.attr,
79 NULL,
80 };
81
82 static const struct attribute_group ad5930_attribute_group = {
83 .attrs = ad5930_attributes,
84 };
85
86 static const struct iio_info ad5930_info = {
87 .attrs = &ad5930_attribute_group,
88 .driver_module = THIS_MODULE,
89 };
90
ad5930_probe(struct spi_device * spi)91 static int ad5930_probe(struct spi_device *spi)
92 {
93 struct ad5930_state *st;
94 struct iio_dev *idev;
95 int ret = 0;
96
97 idev = iio_device_alloc(sizeof(*st));
98 if (idev == NULL) {
99 ret = -ENOMEM;
100 goto error_ret;
101 }
102 spi_set_drvdata(spi, idev);
103 st = iio_priv(idev);
104
105 mutex_init(&st->lock);
106 st->sdev = spi;
107 idev->dev.parent = &spi->dev;
108 idev->info = &ad5930_info;
109 idev->modes = INDIO_DIRECT_MODE;
110
111 ret = iio_device_register(idev);
112 if (ret)
113 goto error_free_dev;
114 spi->max_speed_hz = 2000000;
115 spi->mode = SPI_MODE_3;
116 spi->bits_per_word = 16;
117 spi_setup(spi);
118
119 return 0;
120
121 error_free_dev:
122 iio_device_free(idev);
123 error_ret:
124 return ret;
125 }
126
ad5930_remove(struct spi_device * spi)127 static int ad5930_remove(struct spi_device *spi)
128 {
129 iio_device_unregister(spi_get_drvdata(spi));
130 iio_device_free(spi_get_drvdata(spi));
131
132 return 0;
133 }
134
135 static struct spi_driver ad5930_driver = {
136 .driver = {
137 .name = DRV_NAME,
138 .owner = THIS_MODULE,
139 },
140 .probe = ad5930_probe,
141 .remove = ad5930_remove,
142 };
143 module_spi_driver(ad5930_driver);
144
145 MODULE_AUTHOR("Cliff Cai");
146 MODULE_DESCRIPTION("Analog Devices ad5930 driver");
147 MODULE_LICENSE("GPL v2");
148 MODULE_ALIAS("spi:" DRV_NAME);
149