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-rw-r--r--drivers/iio/adc/ad7923.c383
1 files changed, 383 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7923.c b/drivers/iio/adc/ad7923.c
new file mode 100644
index 000000000000..97fa0d3dc4aa
--- /dev/null
+++ b/drivers/iio/adc/ad7923.c
@@ -0,0 +1,383 @@
1/*
2 * AD7904/AD7914/AD7923/AD7924 SPI ADC driver
3 *
4 * Copyright 2011 Analog Devices Inc (from AD7923 Driver)
5 * Copyright 2012 CS Systemes d'Information
6 *
7 * Licensed under the GPL-2.
8 */
9
10#include <linux/device.h>
11#include <linux/kernel.h>
12#include <linux/slab.h>
13#include <linux/sysfs.h>
14#include <linux/spi/spi.h>
15#include <linux/regulator/consumer.h>
16#include <linux/err.h>
17#include <linux/delay.h>
18#include <linux/module.h>
19#include <linux/interrupt.h>
20
21#include <linux/iio/iio.h>
22#include <linux/iio/sysfs.h>
23#include <linux/iio/buffer.h>
24#include <linux/iio/trigger_consumer.h>
25#include <linux/iio/triggered_buffer.h>
26
27#define AD7923_WRITE_CR (1 << 11) /* write control register */
28#define AD7923_RANGE (1 << 1) /* range to REFin */
29#define AD7923_CODING (1 << 0) /* coding is straight binary */
30#define AD7923_PM_MODE_AS (1) /* auto shutdown */
31#define AD7923_PM_MODE_FS (2) /* full shutdown */
32#define AD7923_PM_MODE_OPS (3) /* normal operation */
33#define AD7923_CHANNEL_0 (0) /* analog input 0 */
34#define AD7923_CHANNEL_1 (1) /* analog input 1 */
35#define AD7923_CHANNEL_2 (2) /* analog input 2 */
36#define AD7923_CHANNEL_3 (3) /* analog input 3 */
37#define AD7923_SEQUENCE_OFF (0) /* no sequence fonction */
38#define AD7923_SEQUENCE_PROTECT (2) /* no interrupt write cycle */
39#define AD7923_SEQUENCE_ON (3) /* continuous sequence */
40
41#define AD7923_MAX_CHAN 4
42
43#define AD7923_PM_MODE_WRITE(mode) (mode << 4) /* write mode */
44#define AD7923_CHANNEL_WRITE(channel) (channel << 6) /* write channel */
45#define AD7923_SEQUENCE_WRITE(sequence) (((sequence & 1) << 3) \
46 + ((sequence & 2) << 9))
47 /* write sequence fonction */
48/* left shift for CR : bit 11 transmit in first */
49#define AD7923_SHIFT_REGISTER 4
50
51/* val = value, dec = left shift, bits = number of bits of the mask */
52#define EXTRACT(val, dec, bits) ((val >> dec) & ((1 << bits) - 1))
53
54struct ad7923_state {
55 struct spi_device *spi;
56 struct spi_transfer ring_xfer[5];
57 struct spi_transfer scan_single_xfer[2];
58 struct spi_message ring_msg;
59 struct spi_message scan_single_msg;
60
61 struct regulator *reg;
62
63 unsigned int settings;
64
65 /*
66 * DMA (thus cache coherency maintenance) requires the
67 * transfer buffers to live in their own cache lines.
68 */
69 __be16 rx_buf[4] ____cacheline_aligned;
70 __be16 tx_buf[4];
71};
72
73struct ad7923_chip_info {
74 const struct iio_chan_spec *channels;
75 unsigned int num_channels;
76};
77
78enum ad7923_id {
79 AD7904,
80 AD7914,
81 AD7924,
82};
83
84#define AD7923_V_CHAN(index, bits) \
85 { \
86 .type = IIO_VOLTAGE, \
87 .indexed = 1, \
88 .channel = index, \
89 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
90 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
91 .address = index, \
92 .scan_index = index, \
93 .scan_type = { \
94 .sign = 'u', \
95 .realbits = (bits), \
96 .storagebits = 16, \
97 .endianness = IIO_BE, \
98 }, \
99 }
100
101#define DECLARE_AD7923_CHANNELS(name, bits) \
102const struct iio_chan_spec name ## _channels[] = { \
103 AD7923_V_CHAN(0, bits), \
104 AD7923_V_CHAN(1, bits), \
105 AD7923_V_CHAN(2, bits), \
106 AD7923_V_CHAN(3, bits), \
107 IIO_CHAN_SOFT_TIMESTAMP(4), \
108}
109
110static DECLARE_AD7923_CHANNELS(ad7904, 8);
111static DECLARE_AD7923_CHANNELS(ad7914, 10);
112static DECLARE_AD7923_CHANNELS(ad7924, 12);
113
114static const struct ad7923_chip_info ad7923_chip_info[] = {
115 [AD7904] = {
116 .channels = ad7904_channels,
117 .num_channels = ARRAY_SIZE(ad7904_channels),
118 },
119 [AD7914] = {
120 .channels = ad7914_channels,
121 .num_channels = ARRAY_SIZE(ad7914_channels),
122 },
123 [AD7924] = {
124 .channels = ad7924_channels,
125 .num_channels = ARRAY_SIZE(ad7924_channels),
126 },
127};
128
129/**
130 * ad7923_update_scan_mode() setup the spi transfer buffer for the new scan mask
131 **/
132static int ad7923_update_scan_mode(struct iio_dev *indio_dev,
133 const unsigned long *active_scan_mask)
134{
135 struct ad7923_state *st = iio_priv(indio_dev);
136 int i, cmd, len;
137
138 len = 0;
139 for_each_set_bit(i, active_scan_mask, AD7923_MAX_CHAN) {
140 cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(i) |
141 AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) |
142 st->settings;
143 cmd <<= AD7923_SHIFT_REGISTER;
144 st->tx_buf[len++] = cpu_to_be16(cmd);
145 }
146 /* build spi ring message */
147 st->ring_xfer[0].tx_buf = &st->tx_buf[0];
148 st->ring_xfer[0].len = len;
149 st->ring_xfer[0].cs_change = 1;
150
151 spi_message_init(&st->ring_msg);
152 spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
153
154 for (i = 0; i < len; i++) {
155 st->ring_xfer[i + 1].rx_buf = &st->rx_buf[i];
156 st->ring_xfer[i + 1].len = 2;
157 st->ring_xfer[i + 1].cs_change = 1;
158 spi_message_add_tail(&st->ring_xfer[i + 1], &st->ring_msg);
159 }
160 /* make sure last transfer cs_change is not set */
161 st->ring_xfer[i + 1].cs_change = 0;
162
163 return 0;
164}
165
166/**
167 * ad7923_trigger_handler() bh of trigger launched polling to ring buffer
168 *
169 * Currently there is no option in this driver to disable the saving of
170 * timestamps within the ring.
171 **/
172static irqreturn_t ad7923_trigger_handler(int irq, void *p)
173{
174 struct iio_poll_func *pf = p;
175 struct iio_dev *indio_dev = pf->indio_dev;
176 struct ad7923_state *st = iio_priv(indio_dev);
177 s64 time_ns = 0;
178 int b_sent;
179
180 b_sent = spi_sync(st->spi, &st->ring_msg);
181 if (b_sent)
182 goto done;
183
184 if (indio_dev->scan_timestamp) {
185 time_ns = iio_get_time_ns();
186 memcpy((u8 *)st->rx_buf + indio_dev->scan_bytes - sizeof(s64),
187 &time_ns, sizeof(time_ns));
188 }
189
190 iio_push_to_buffers(indio_dev, (u8 *)st->rx_buf);
191
192done:
193 iio_trigger_notify_done(indio_dev->trig);
194
195 return IRQ_HANDLED;
196}
197
198static int ad7923_scan_direct(struct ad7923_state *st, unsigned ch)
199{
200 int ret, cmd;
201
202 cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(ch) |
203 AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) |
204 st->settings;
205 cmd <<= AD7923_SHIFT_REGISTER;
206 st->tx_buf[0] = cpu_to_be16(cmd);
207
208 ret = spi_sync(st->spi, &st->scan_single_msg);
209 if (ret)
210 return ret;
211
212 return be16_to_cpu(st->rx_buf[0]);
213}
214
215static int ad7923_get_range(struct ad7923_state *st)
216{
217 int vref;
218
219 vref = regulator_get_voltage(st->reg);
220 if (vref < 0)
221 return vref;
222
223 vref /= 1000;
224
225 if (!(st->settings & AD7923_RANGE))
226 vref *= 2;
227
228 return vref;
229}
230
231static int ad7923_read_raw(struct iio_dev *indio_dev,
232 struct iio_chan_spec const *chan,
233 int *val,
234 int *val2,
235 long m)
236{
237 int ret;
238 struct ad7923_state *st = iio_priv(indio_dev);
239
240 switch (m) {
241 case IIO_CHAN_INFO_RAW:
242 mutex_lock(&indio_dev->mlock);
243 if (iio_buffer_enabled(indio_dev))
244 ret = -EBUSY;
245 else
246 ret = ad7923_scan_direct(st, chan->address);
247 mutex_unlock(&indio_dev->mlock);
248
249 if (ret < 0)
250 return ret;
251
252 if (chan->address == EXTRACT(ret, 12, 4))
253 *val = EXTRACT(ret, 0, 12);
254 else
255 return -EIO;
256
257 return IIO_VAL_INT;
258 case IIO_CHAN_INFO_SCALE:
259 ret = ad7923_get_range(st);
260 if (ret < 0)
261 return ret;
262 *val = ret;
263 *val2 = chan->scan_type.realbits;
264 return IIO_VAL_FRACTIONAL_LOG2;
265 }
266 return -EINVAL;
267}
268
269static const struct iio_info ad7923_info = {
270 .read_raw = &ad7923_read_raw,
271 .update_scan_mode = ad7923_update_scan_mode,
272 .driver_module = THIS_MODULE,
273};
274
275static int ad7923_probe(struct spi_device *spi)
276{
277 struct ad7923_state *st;
278 struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
279 const struct ad7923_chip_info *info;
280 int ret;
281
282 if (indio_dev == NULL)
283 return -ENOMEM;
284
285 st = iio_priv(indio_dev);
286
287 spi_set_drvdata(spi, indio_dev);
288
289 st->spi = spi;
290 st->settings = AD7923_CODING | AD7923_RANGE |
291 AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS);
292
293 info = &ad7923_chip_info[spi_get_device_id(spi)->driver_data];
294
295 indio_dev->name = spi_get_device_id(spi)->name;
296 indio_dev->dev.parent = &spi->dev;
297 indio_dev->modes = INDIO_DIRECT_MODE;
298 indio_dev->channels = info->channels;
299 indio_dev->num_channels = info->num_channels;
300 indio_dev->info = &ad7923_info;
301
302 /* Setup default message */
303
304 st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
305 st->scan_single_xfer[0].len = 2;
306 st->scan_single_xfer[0].cs_change = 1;
307 st->scan_single_xfer[1].rx_buf = &st->rx_buf[0];
308 st->scan_single_xfer[1].len = 2;
309
310 spi_message_init(&st->scan_single_msg);
311 spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
312 spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
313
314 st->reg = regulator_get(&spi->dev, "refin");
315 if (IS_ERR(st->reg)) {
316 ret = PTR_ERR(st->reg);
317 goto error_free;
318 }
319 ret = regulator_enable(st->reg);
320 if (ret)
321 goto error_put_reg;
322
323 ret = iio_triggered_buffer_setup(indio_dev, NULL,
324 &ad7923_trigger_handler, NULL);
325 if (ret)
326 goto error_disable_reg;
327
328 ret = iio_device_register(indio_dev);
329 if (ret)
330 goto error_cleanup_ring;
331
332 return 0;
333
334error_cleanup_ring:
335 iio_triggered_buffer_cleanup(indio_dev);
336error_disable_reg:
337 regulator_disable(st->reg);
338error_put_reg:
339 regulator_put(st->reg);
340error_free:
341 iio_device_free(indio_dev);
342
343 return ret;
344}
345
346static int ad7923_remove(struct spi_device *spi)
347{
348 struct iio_dev *indio_dev = spi_get_drvdata(spi);
349 struct ad7923_state *st = iio_priv(indio_dev);
350
351 iio_device_unregister(indio_dev);
352 iio_triggered_buffer_cleanup(indio_dev);
353 regulator_disable(st->reg);
354 regulator_put(st->reg);
355 iio_device_free(indio_dev);
356
357 return 0;
358}
359
360static const struct spi_device_id ad7923_id[] = {
361 {"ad7904", AD7904},
362 {"ad7914", AD7914},
363 {"ad7923", AD7924},
364 {"ad7924", AD7924},
365 {}
366};
367MODULE_DEVICE_TABLE(spi, ad7923_id);
368
369static struct spi_driver ad7923_driver = {
370 .driver = {
371 .name = "ad7923",
372 .owner = THIS_MODULE,
373 },
374 .probe = ad7923_probe,
375 .remove = ad7923_remove,
376 .id_table = ad7923_id,
377};
378module_spi_driver(ad7923_driver);
379
380MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
381MODULE_AUTHOR("Patrick Vasseur <patrick.vasseur@c-s.fr>");
382MODULE_DESCRIPTION("Analog Devices AD7904/AD7914/AD7923/AD7924 ADC");
383MODULE_LICENSE("GPL v2");
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-01 13:30:42 -0400