1 /*
2  * Driver for ADI Direct Digital Synthesis ad9951
3  *
4  * Copyright (c) 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 
18 #include "../iio.h"
19 #include "../sysfs.h"
20 
21 #define DRV_NAME "ad9951"
22 
23 #define CFR1 0x0
24 #define CFR2 0x1
25 
26 #define AUTO_OSK	(1)
27 #define OSKEN		(1 << 1)
28 #define LOAD_ARR	(1 << 2)
29 
30 #define AUTO_SYNC	(1 << 7)
31 
32 #define LSB_FST		(1)
33 #define SDIO_IPT	(1 << 1)
34 #define CLR_PHA		(1 << 2)
35 #define SINE_OPT	(1 << 4)
36 #define ACLR_PHA	(1 << 5)
37 
38 #define VCO_RANGE	(1 << 2)
39 
40 #define CRS_OPT		(1 << 1)
41 #define HMANU_SYNC	(1 << 2)
42 #define HSPD_SYNC	(1 << 3)
43 
44 /* Register format: 1 byte addr + value */
45 struct ad9951_config {
46 	u8 asf[3];
47 	u8 arr[2];
48 	u8 ftw0[5];
49 	u8 ftw1[3];
50 };
51 
52 struct ad9951_state {
53 	struct mutex lock;
54 	struct iio_dev *idev;
55 	struct spi_device *sdev;
56 };
57 
ad9951_set_parameter(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)58 static ssize_t ad9951_set_parameter(struct device *dev,
59 					struct device_attribute *attr,
60 					const char *buf,
61 					size_t len)
62 {
63 	struct spi_message msg;
64 	struct spi_transfer xfer;
65 	int ret;
66 	struct ad9951_config *config = (struct ad9951_config *)buf;
67 	struct iio_dev *idev = dev_get_drvdata(dev);
68 	struct ad9951_state *st = idev->dev_data;
69 
70 	xfer.len = 3;
71 	xfer.tx_buf = &config->asf[0];
72 	mutex_lock(&st->lock);
73 
74 	spi_message_init(&msg);
75 	spi_message_add_tail(&xfer, &msg);
76 	ret = spi_sync(st->sdev, &msg);
77 	if (ret)
78 		goto error_ret;
79 
80 	xfer.len = 2;
81 	xfer.tx_buf = &config->arr[0];
82 
83 	spi_message_init(&msg);
84 	spi_message_add_tail(&xfer, &msg);
85 	ret = spi_sync(st->sdev, &msg);
86 	if (ret)
87 		goto error_ret;
88 
89 	xfer.len = 5;
90 	xfer.tx_buf = &config->ftw0[0];
91 
92 	spi_message_init(&msg);
93 	spi_message_add_tail(&xfer, &msg);
94 	ret = spi_sync(st->sdev, &msg);
95 	if (ret)
96 		goto error_ret;
97 
98 	xfer.len = 3;
99 	xfer.tx_buf = &config->ftw1[0];
100 
101 	spi_message_init(&msg);
102 	spi_message_add_tail(&xfer, &msg);
103 	ret = spi_sync(st->sdev, &msg);
104 	if (ret)
105 		goto error_ret;
106 error_ret:
107 	mutex_unlock(&st->lock);
108 
109 	return ret ? ret : len;
110 }
111 
112 static IIO_DEVICE_ATTR(dds, S_IWUSR, NULL, ad9951_set_parameter, 0);
113 
ad9951_init(struct ad9951_state * st)114 static void ad9951_init(struct ad9951_state *st)
115 {
116 	struct spi_message msg;
117 	struct spi_transfer xfer;
118 	int ret;
119 	u8 cfr[5];
120 
121 	cfr[0] = CFR1;
122 	cfr[1] = 0;
123 	cfr[2] = LSB_FST | CLR_PHA | SINE_OPT | ACLR_PHA;
124 	cfr[3] = AUTO_OSK | OSKEN | LOAD_ARR;
125 	cfr[4] = 0;
126 
127 	mutex_lock(&st->lock);
128 
129 	xfer.len = 5;
130 	xfer.tx_buf = &cfr;
131 
132 	spi_message_init(&msg);
133 	spi_message_add_tail(&xfer, &msg);
134 	ret = spi_sync(st->sdev, &msg);
135 	if (ret)
136 		goto error_ret;
137 
138 	cfr[0] = CFR2;
139 	cfr[1] = VCO_RANGE;
140 	cfr[2] = HSPD_SYNC;
141 	cfr[3] = 0;
142 
143 	xfer.len = 4;
144 	xfer.tx_buf = &cfr;
145 
146 	spi_message_init(&msg);
147 	spi_message_add_tail(&xfer, &msg);
148 	ret = spi_sync(st->sdev, &msg);
149 	if (ret)
150 		goto error_ret;
151 
152 error_ret:
153 	mutex_unlock(&st->lock);
154 
155 
156 
157 }
158 
159 static struct attribute *ad9951_attributes[] = {
160 	&iio_dev_attr_dds.dev_attr.attr,
161 	NULL,
162 };
163 
164 static const struct attribute_group ad9951_attribute_group = {
165 	.name = DRV_NAME,
166 	.attrs = ad9951_attributes,
167 };
168 
ad9951_probe(struct spi_device * spi)169 static int __devinit ad9951_probe(struct spi_device *spi)
170 {
171 	struct ad9951_state *st;
172 	int ret = 0;
173 
174 	st = kzalloc(sizeof(*st), GFP_KERNEL);
175 	if (st == NULL) {
176 		ret = -ENOMEM;
177 		goto error_ret;
178 	}
179 	spi_set_drvdata(spi, st);
180 
181 	mutex_init(&st->lock);
182 	st->sdev = spi;
183 
184 	st->idev = iio_allocate_device();
185 	if (st->idev == NULL) {
186 		ret = -ENOMEM;
187 		goto error_free_st;
188 	}
189 	st->idev->dev.parent = &spi->dev;
190 	st->idev->num_interrupt_lines = 0;
191 	st->idev->event_attrs = NULL;
192 
193 	st->idev->attrs = &ad9951_attribute_group;
194 	st->idev->dev_data = (void *)(st);
195 	st->idev->driver_module = THIS_MODULE;
196 	st->idev->modes = INDIO_DIRECT_MODE;
197 
198 	ret = iio_device_register(st->idev);
199 	if (ret)
200 		goto error_free_dev;
201 	spi->max_speed_hz = 2000000;
202 	spi->mode = SPI_MODE_3;
203 	spi->bits_per_word = 8;
204 	spi_setup(spi);
205 	ad9951_init(st);
206 	return 0;
207 
208 error_free_dev:
209 	iio_free_device(st->idev);
210 error_free_st:
211 	kfree(st);
212 error_ret:
213 	return ret;
214 }
215 
ad9951_remove(struct spi_device * spi)216 static int __devexit ad9951_remove(struct spi_device *spi)
217 {
218 	struct ad9951_state *st = spi_get_drvdata(spi);
219 
220 	iio_device_unregister(st->idev);
221 	kfree(st);
222 
223 	return 0;
224 }
225 
226 static struct spi_driver ad9951_driver = {
227 	.driver = {
228 		.name = DRV_NAME,
229 		.owner = THIS_MODULE,
230 	},
231 	.probe = ad9951_probe,
232 	.remove = __devexit_p(ad9951_remove),
233 };
234 
ad9951_spi_init(void)235 static __init int ad9951_spi_init(void)
236 {
237 	return spi_register_driver(&ad9951_driver);
238 }
239 module_init(ad9951_spi_init);
240 
ad9951_spi_exit(void)241 static __exit void ad9951_spi_exit(void)
242 {
243 	spi_unregister_driver(&ad9951_driver);
244 }
245 module_exit(ad9951_spi_exit);
246 
247 MODULE_AUTHOR("Cliff Cai");
248 MODULE_DESCRIPTION("Analog Devices ad9951 driver");
249 MODULE_LICENSE("GPL v2");
250