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 "../iio.h"
20 #include "../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_message msg;
48 struct spi_transfer xfer;
49 int ret;
50 struct ad5903_config *config = (struct ad5903_config *)buf;
51 struct iio_dev *idev = dev_get_drvdata(dev);
52 struct ad5930_state *st = iio_priv(idev);
53
54 config->control = (config->control & ~value_mask);
55 config->incnum = (config->control & ~value_mask) | (1 << addr_shift);
56 config->frqdelt[0] = (config->control & ~value_mask) | (2 << addr_shift);
57 config->frqdelt[1] = (config->control & ~value_mask) | 3 << addr_shift;
58 config->incitvl = (config->control & ~value_mask) | 4 << addr_shift;
59 config->buritvl = (config->control & ~value_mask) | 8 << addr_shift;
60 config->strtfrq[0] = (config->control & ~value_mask) | 0xc << addr_shift;
61 config->strtfrq[1] = (config->control & ~value_mask) | 0xd << addr_shift;
62
63 xfer.len = len;
64 xfer.tx_buf = config;
65 mutex_lock(&st->lock);
66
67 spi_message_init(&msg);
68 spi_message_add_tail(&xfer, &msg);
69 ret = spi_sync(st->sdev, &msg);
70 if (ret)
71 goto error_ret;
72 error_ret:
73 mutex_unlock(&st->lock);
74
75 return ret ? ret : len;
76 }
77
78 static IIO_DEVICE_ATTR(dds, S_IWUSR, NULL, ad5930_set_parameter, 0);
79
80 static struct attribute *ad5930_attributes[] = {
81 &iio_dev_attr_dds.dev_attr.attr,
82 NULL,
83 };
84
85 static const struct attribute_group ad5930_attribute_group = {
86 .attrs = ad5930_attributes,
87 };
88
89 static const struct iio_info ad5930_info = {
90 .attrs = &ad5930_attribute_group,
91 .driver_module = THIS_MODULE,
92 };
93
ad5930_probe(struct spi_device * spi)94 static int __devinit ad5930_probe(struct spi_device *spi)
95 {
96 struct ad5930_state *st;
97 struct iio_dev *idev;
98 int ret = 0;
99
100 idev = iio_allocate_device(sizeof(*st));
101 if (idev == NULL) {
102 ret = -ENOMEM;
103 goto error_ret;
104 }
105 spi_set_drvdata(spi, idev);
106 st = iio_priv(idev);
107
108 mutex_init(&st->lock);
109 st->sdev = spi;
110 idev->dev.parent = &spi->dev;
111 idev->info = &ad5930_info;
112 idev->modes = INDIO_DIRECT_MODE;
113
114 ret = iio_device_register(idev);
115 if (ret)
116 goto error_free_dev;
117 spi->max_speed_hz = 2000000;
118 spi->mode = SPI_MODE_3;
119 spi->bits_per_word = 16;
120 spi_setup(spi);
121
122 return 0;
123
124 error_free_dev:
125 iio_free_device(idev);
126 error_ret:
127 return ret;
128 }
129
ad5930_remove(struct spi_device * spi)130 static int __devexit ad5930_remove(struct spi_device *spi)
131 {
132 iio_device_unregister(spi_get_drvdata(spi));
133 iio_free_device(spi_get_drvdata(spi));
134
135 return 0;
136 }
137
138 static struct spi_driver ad5930_driver = {
139 .driver = {
140 .name = DRV_NAME,
141 .owner = THIS_MODULE,
142 },
143 .probe = ad5930_probe,
144 .remove = __devexit_p(ad5930_remove),
145 };
146 module_spi_driver(ad5930_driver);
147
148 MODULE_AUTHOR("Cliff Cai");
149 MODULE_DESCRIPTION("Analog Devices ad5930 driver");
150 MODULE_LICENSE("GPL v2");
151 MODULE_ALIAS("spi:" DRV_NAME);
152