2 * AD7766/AD7767 SPI ADC driver
4 * Copyright 2016 Analog Devices Inc.
6 * Licensed under the GPL-2 or later.
10 #include <linux/delay.h>
11 #include <linux/device.h>
12 #include <linux/err.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/module.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/slab.h>
17 #include <linux/spi/spi.h>
19 #include <linux/iio/iio.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/trigger.h>
22 #include <linux/iio/trigger_consumer.h>
23 #include <linux/iio/triggered_buffer.h>
25 struct ad7766_chip_info {
26 unsigned int decimation_factor;
30 AD7766_SUPPLY_AVDD = 0,
31 AD7766_SUPPLY_DVDD = 1,
32 AD7766_SUPPLY_VREF = 2,
33 AD7766_NUM_SUPPLIES = 3
37 const struct ad7766_chip_info *chip_info;
38 struct spi_device *spi;
40 struct gpio_desc *pd_gpio;
41 struct regulator_bulk_data reg[AD7766_NUM_SUPPLIES];
43 struct iio_trigger *trig;
45 struct spi_transfer xfer;
46 struct spi_message msg;
49 * DMA (thus cache coherency maintenance) requires the
50 * transfer buffers to live in their own cache lines.
51 * Make the buffer large enough for one 24 bit sample and one 64 bit
52 * aligned 64 bit timestamp.
54 unsigned char data[ALIGN(3, sizeof(s64)) + sizeof(s64)]
55 ____cacheline_aligned;
59 * AD7766 and AD7767 variations are interface compatible, the main difference is
60 * analog performance. Both parts will use the same ID.
62 enum ad7766_device_ids {
68 static irqreturn_t ad7766_trigger_handler(int irq, void *p)
70 struct iio_poll_func *pf = p;
71 struct iio_dev *indio_dev = pf->indio_dev;
72 struct ad7766 *ad7766 = iio_priv(indio_dev);
75 ret = spi_sync(ad7766->spi, &ad7766->msg);
79 iio_push_to_buffers_with_timestamp(indio_dev, ad7766->data,
82 iio_trigger_notify_done(indio_dev->trig);
87 static int ad7766_preenable(struct iio_dev *indio_dev)
89 struct ad7766 *ad7766 = iio_priv(indio_dev);
92 ret = regulator_bulk_enable(ARRAY_SIZE(ad7766->reg), ad7766->reg);
94 dev_err(&ad7766->spi->dev, "Failed to enable supplies: %d\n",
99 ret = clk_prepare_enable(ad7766->mclk);
101 dev_err(&ad7766->spi->dev, "Failed to enable MCLK: %d\n", ret);
102 regulator_bulk_disable(ARRAY_SIZE(ad7766->reg), ad7766->reg);
107 gpiod_set_value(ad7766->pd_gpio, 0);
112 static int ad7766_postdisable(struct iio_dev *indio_dev)
114 struct ad7766 *ad7766 = iio_priv(indio_dev);
117 gpiod_set_value(ad7766->pd_gpio, 1);
120 * The PD pin is synchronous to the clock, so give it some time to
121 * notice the change before we disable the clock.
125 clk_disable_unprepare(ad7766->mclk);
126 regulator_bulk_disable(ARRAY_SIZE(ad7766->reg), ad7766->reg);
131 static int ad7766_read_raw(struct iio_dev *indio_dev,
132 const struct iio_chan_spec *chan, int *val, int *val2, long info)
134 struct ad7766 *ad7766 = iio_priv(indio_dev);
135 struct regulator *vref = ad7766->reg[AD7766_SUPPLY_VREF].consumer;
139 case IIO_CHAN_INFO_SCALE:
140 scale_uv = regulator_get_voltage(vref);
143 *val = scale_uv / 1000;
144 *val2 = chan->scan_type.realbits;
145 return IIO_VAL_FRACTIONAL_LOG2;
146 case IIO_CHAN_INFO_SAMP_FREQ:
147 *val = clk_get_rate(ad7766->mclk) /
148 ad7766->chip_info->decimation_factor;
154 static const struct iio_chan_spec ad7766_channels[] = {
158 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
159 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
164 .endianness = IIO_BE,
167 IIO_CHAN_SOFT_TIMESTAMP(1),
170 static const struct ad7766_chip_info ad7766_chip_info[] = {
172 .decimation_factor = 8,
175 .decimation_factor = 16,
178 .decimation_factor = 32,
182 static const struct iio_buffer_setup_ops ad7766_buffer_setup_ops = {
183 .preenable = &ad7766_preenable,
184 .postenable = &iio_triggered_buffer_postenable,
185 .predisable = &iio_triggered_buffer_predisable,
186 .postdisable = &ad7766_postdisable,
189 static const struct iio_info ad7766_info = {
190 .driver_module = THIS_MODULE,
191 .read_raw = &ad7766_read_raw,
194 static irqreturn_t ad7766_irq(int irq, void *private)
196 iio_trigger_poll(private);
200 static int ad7766_set_trigger_state(struct iio_trigger *trig, bool enable)
202 struct ad7766 *ad7766 = iio_trigger_get_drvdata(trig);
205 enable_irq(ad7766->spi->irq);
207 disable_irq(ad7766->spi->irq);
212 static const struct iio_trigger_ops ad7766_trigger_ops = {
213 .owner = THIS_MODULE,
214 .set_trigger_state = ad7766_set_trigger_state,
215 .validate_device = iio_trigger_validate_own_device,
218 static int ad7766_probe(struct spi_device *spi)
220 const struct spi_device_id *id = spi_get_device_id(spi);
221 struct iio_dev *indio_dev;
222 struct ad7766 *ad7766;
225 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ad7766));
229 ad7766 = iio_priv(indio_dev);
230 ad7766->chip_info = &ad7766_chip_info[id->driver_data];
232 ad7766->mclk = devm_clk_get(&spi->dev, "mclk");
233 if (IS_ERR(ad7766->mclk))
234 return PTR_ERR(ad7766->mclk);
236 ad7766->reg[AD7766_SUPPLY_AVDD].supply = "avdd";
237 ad7766->reg[AD7766_SUPPLY_DVDD].supply = "dvdd";
238 ad7766->reg[AD7766_SUPPLY_VREF].supply = "vref";
240 ret = devm_regulator_bulk_get(&spi->dev, ARRAY_SIZE(ad7766->reg),
245 ad7766->pd_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown",
247 if (IS_ERR(ad7766->pd_gpio))
248 return PTR_ERR(ad7766->pd_gpio);
250 indio_dev->dev.parent = &spi->dev;
251 indio_dev->name = spi_get_device_id(spi)->name;
252 indio_dev->modes = INDIO_DIRECT_MODE;
253 indio_dev->channels = ad7766_channels;
254 indio_dev->num_channels = ARRAY_SIZE(ad7766_channels);
255 indio_dev->info = &ad7766_info;
258 ad7766->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
259 indio_dev->name, indio_dev->id);
263 ad7766->trig->ops = &ad7766_trigger_ops;
264 ad7766->trig->dev.parent = &spi->dev;
265 iio_trigger_set_drvdata(ad7766->trig, ad7766);
267 ret = devm_request_irq(&spi->dev, spi->irq, ad7766_irq,
268 IRQF_TRIGGER_FALLING, dev_name(&spi->dev),
274 * The device generates interrupts as long as it is powered up.
275 * Some platforms might not allow the option to power it down so
276 * disable the interrupt to avoid extra load on the system
278 disable_irq(spi->irq);
280 ret = devm_iio_trigger_register(&spi->dev, ad7766->trig);
285 spi_set_drvdata(spi, indio_dev);
289 /* First byte always 0 */
290 ad7766->xfer.rx_buf = &ad7766->data[1];
291 ad7766->xfer.len = 3;
293 spi_message_init(&ad7766->msg);
294 spi_message_add_tail(&ad7766->xfer, &ad7766->msg);
296 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
297 &iio_pollfunc_store_time, &ad7766_trigger_handler,
298 &ad7766_buffer_setup_ops);
302 ret = devm_iio_device_register(&spi->dev, indio_dev);
308 static const struct spi_device_id ad7766_id[] = {
309 {"ad7766", ID_AD7766},
310 {"ad7766-1", ID_AD7766_1},
311 {"ad7766-2", ID_AD7766_2},
312 {"ad7767", ID_AD7766},
313 {"ad7767-1", ID_AD7766_1},
314 {"ad7767-2", ID_AD7766_2},
317 MODULE_DEVICE_TABLE(spi, ad7766_id);
319 static struct spi_driver ad7766_driver = {
323 .probe = ad7766_probe,
324 .id_table = ad7766_id,
326 module_spi_driver(ad7766_driver);
328 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
329 MODULE_DESCRIPTION("Analog Devices AD7766 and AD7767 ADCs driver support");
330 MODULE_LICENSE("GPL v2");