2 * AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
4 * Copyright 2010 Analog Devices Inc.
6 * Licensed under the GPL-2 or later.
9 #include <linux/device.h>
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/sysfs.h>
13 #include <linux/spi/spi.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/err.h>
16 #include <linux/module.h>
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/trigger_consumer.h>
22 #include <linux/iio/triggered_buffer.h>
24 #define RES_MASK(bits) ((1 << (bits)) - 1)
28 struct ad7476_chip_info
{
29 unsigned int int_vref_uv
;
30 struct iio_chan_spec channel
[2];
31 void (*reset
)(struct ad7476_state
*);
35 struct spi_device
*spi
;
36 const struct ad7476_chip_info
*chip_info
;
37 struct regulator
*reg
;
38 struct spi_transfer xfer
;
39 struct spi_message msg
;
41 * DMA (thus cache coherency maintenance) requires the
42 * transfer buffers to live in their own cache lines.
43 * Make the buffer large enough for one 16 bit sample and one 64 bit
44 * aligned 64 bit timestamp.
46 unsigned char data
[ALIGN(2, sizeof(s64
)) + sizeof(s64
)]
47 ____cacheline_aligned
;
50 enum ad7476_supported_device_ids
{
62 static irqreturn_t
ad7476_trigger_handler(int irq
, void *p
)
64 struct iio_poll_func
*pf
= p
;
65 struct iio_dev
*indio_dev
= pf
->indio_dev
;
66 struct ad7476_state
*st
= iio_priv(indio_dev
);
70 b_sent
= spi_sync(st
->spi
, &st
->msg
);
74 time_ns
= iio_get_time_ns();
76 if (indio_dev
->scan_timestamp
)
77 ((s64
*)st
->data
)[1] = time_ns
;
79 iio_push_to_buffers(indio_dev
, st
->data
);
81 iio_trigger_notify_done(indio_dev
->trig
);
86 static void ad7091_reset(struct ad7476_state
*st
)
88 /* Any transfers with 8 scl cycles will reset the device */
89 spi_read(st
->spi
, st
->data
, 1);
92 static int ad7476_scan_direct(struct ad7476_state
*st
)
96 ret
= spi_sync(st
->spi
, &st
->msg
);
100 return be16_to_cpup((__be16
*)st
->data
);
103 static int ad7476_read_raw(struct iio_dev
*indio_dev
,
104 struct iio_chan_spec
const *chan
,
110 struct ad7476_state
*st
= iio_priv(indio_dev
);
114 case IIO_CHAN_INFO_RAW
:
115 mutex_lock(&indio_dev
->mlock
);
116 if (iio_buffer_enabled(indio_dev
))
119 ret
= ad7476_scan_direct(st
);
120 mutex_unlock(&indio_dev
->mlock
);
124 *val
= (ret
>> st
->chip_info
->channel
[0].scan_type
.shift
) &
125 RES_MASK(st
->chip_info
->channel
[0].scan_type
.realbits
);
127 case IIO_CHAN_INFO_SCALE
:
128 if (!st
->chip_info
->int_vref_uv
) {
129 scale_uv
= regulator_get_voltage(st
->reg
);
133 scale_uv
= st
->chip_info
->int_vref_uv
;
135 scale_uv
>>= chan
->scan_type
.realbits
;
136 *val
= scale_uv
/ 1000;
137 *val2
= (scale_uv
% 1000) * 1000;
138 return IIO_VAL_INT_PLUS_MICRO
;
143 #define _AD7476_CHAN(bits, _shift, _info_mask_sep) \
145 .type = IIO_VOLTAGE, \
147 .info_mask_separate = _info_mask_sep, \
148 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
151 .realbits = (bits), \
154 .endianness = IIO_BE, \
158 #define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
159 BIT(IIO_CHAN_INFO_RAW))
160 #define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
161 BIT(IIO_CHAN_INFO_RAW))
162 #define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
164 static const struct ad7476_chip_info ad7476_chip_info_tbl
[] = {
166 .channel
[0] = AD7091R_CHAN(12),
167 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
168 .reset
= ad7091_reset
,
171 .channel
[0] = AD7940_CHAN(12),
172 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
175 .channel
[0] = AD7940_CHAN(10),
176 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
179 .channel
[0] = AD7940_CHAN(8),
180 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
183 .channel
[0] = AD7476_CHAN(12),
184 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
187 .channel
[0] = AD7476_CHAN(10),
188 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
191 .channel
[0] = AD7476_CHAN(8),
192 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
195 .channel
[0] = AD7476_CHAN(12),
196 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
197 .int_vref_uv
= 2500000,
200 .channel
[0] = AD7940_CHAN(14),
201 .channel
[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
205 static const struct iio_info ad7476_info
= {
206 .driver_module
= THIS_MODULE
,
207 .read_raw
= &ad7476_read_raw
,
210 static int ad7476_probe(struct spi_device
*spi
)
212 struct ad7476_state
*st
;
213 struct iio_dev
*indio_dev
;
216 indio_dev
= iio_device_alloc(sizeof(*st
));
217 if (indio_dev
== NULL
) {
221 st
= iio_priv(indio_dev
);
223 &ad7476_chip_info_tbl
[spi_get_device_id(spi
)->driver_data
];
225 st
->reg
= regulator_get(&spi
->dev
, "vcc");
226 if (IS_ERR(st
->reg
)) {
227 ret
= PTR_ERR(st
->reg
);
231 ret
= regulator_enable(st
->reg
);
235 spi_set_drvdata(spi
, indio_dev
);
239 /* Establish that the iio_dev is a child of the spi device */
240 indio_dev
->dev
.parent
= &spi
->dev
;
241 indio_dev
->name
= spi_get_device_id(spi
)->name
;
242 indio_dev
->modes
= INDIO_DIRECT_MODE
;
243 indio_dev
->channels
= st
->chip_info
->channel
;
244 indio_dev
->num_channels
= 2;
245 indio_dev
->info
= &ad7476_info
;
246 /* Setup default message */
248 st
->xfer
.rx_buf
= &st
->data
;
249 st
->xfer
.len
= st
->chip_info
->channel
[0].scan_type
.storagebits
/ 8;
251 spi_message_init(&st
->msg
);
252 spi_message_add_tail(&st
->xfer
, &st
->msg
);
254 ret
= iio_triggered_buffer_setup(indio_dev
, NULL
,
255 &ad7476_trigger_handler
, NULL
);
257 goto error_disable_reg
;
259 if (st
->chip_info
->reset
)
260 st
->chip_info
->reset(st
);
262 ret
= iio_device_register(indio_dev
);
264 goto error_ring_unregister
;
267 error_ring_unregister
:
268 iio_triggered_buffer_cleanup(indio_dev
);
270 regulator_disable(st
->reg
);
272 regulator_put(st
->reg
);
274 iio_device_free(indio_dev
);
280 static int ad7476_remove(struct spi_device
*spi
)
282 struct iio_dev
*indio_dev
= spi_get_drvdata(spi
);
283 struct ad7476_state
*st
= iio_priv(indio_dev
);
285 iio_device_unregister(indio_dev
);
286 iio_triggered_buffer_cleanup(indio_dev
);
287 regulator_disable(st
->reg
);
288 regulator_put(st
->reg
);
289 iio_device_free(indio_dev
);
294 static const struct spi_device_id ad7476_id
[] = {
295 {"ad7091r", ID_AD7091R
},
296 {"ad7273", ID_AD7277
},
297 {"ad7274", ID_AD7276
},
298 {"ad7276", ID_AD7276
},
299 {"ad7277", ID_AD7277
},
300 {"ad7278", ID_AD7278
},
301 {"ad7466", ID_AD7466
},
302 {"ad7467", ID_AD7467
},
303 {"ad7468", ID_AD7468
},
304 {"ad7475", ID_AD7466
},
305 {"ad7476", ID_AD7466
},
306 {"ad7476a", ID_AD7466
},
307 {"ad7477", ID_AD7467
},
308 {"ad7477a", ID_AD7467
},
309 {"ad7478", ID_AD7468
},
310 {"ad7478a", ID_AD7468
},
311 {"ad7495", ID_AD7495
},
312 {"ad7910", ID_AD7467
},
313 {"ad7920", ID_AD7466
},
314 {"ad7940", ID_AD7940
},
317 MODULE_DEVICE_TABLE(spi
, ad7476_id
);
319 static struct spi_driver ad7476_driver
= {
322 .owner
= THIS_MODULE
,
324 .probe
= ad7476_probe
,
325 .remove
= ad7476_remove
,
326 .id_table
= ad7476_id
,
328 module_spi_driver(ad7476_driver
);
330 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
331 MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
332 MODULE_LICENSE("GPL v2");