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322 lines
7.6 KiB
322 lines
7.6 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* AD7766/AD7767 SPI ADC driver |
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* |
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* Copyright 2016 Analog Devices Inc. |
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*/ |
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#include <linux/clk.h> |
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#include <linux/delay.h> |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/gpio/consumer.h> |
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#include <linux/module.h> |
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#include <linux/regulator/consumer.h> |
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#include <linux/slab.h> |
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#include <linux/spi/spi.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/buffer.h> |
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#include <linux/iio/trigger.h> |
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#include <linux/iio/trigger_consumer.h> |
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#include <linux/iio/triggered_buffer.h> |
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struct ad7766_chip_info { |
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unsigned int decimation_factor; |
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}; |
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enum { |
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AD7766_SUPPLY_AVDD = 0, |
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AD7766_SUPPLY_DVDD = 1, |
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AD7766_SUPPLY_VREF = 2, |
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AD7766_NUM_SUPPLIES = 3 |
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}; |
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struct ad7766 { |
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const struct ad7766_chip_info *chip_info; |
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struct spi_device *spi; |
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struct clk *mclk; |
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struct gpio_desc *pd_gpio; |
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struct regulator_bulk_data reg[AD7766_NUM_SUPPLIES]; |
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struct iio_trigger *trig; |
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struct spi_transfer xfer; |
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struct spi_message msg; |
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/* |
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* DMA (thus cache coherency maintenance) requires the |
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* transfer buffers to live in their own cache lines. |
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* Make the buffer large enough for one 24 bit sample and one 64 bit |
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* aligned 64 bit timestamp. |
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*/ |
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unsigned char data[ALIGN(3, sizeof(s64)) + sizeof(s64)] |
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____cacheline_aligned; |
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}; |
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/* |
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* AD7766 and AD7767 variations are interface compatible, the main difference is |
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* analog performance. Both parts will use the same ID. |
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*/ |
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enum ad7766_device_ids { |
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ID_AD7766, |
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ID_AD7766_1, |
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ID_AD7766_2, |
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}; |
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static irqreturn_t ad7766_trigger_handler(int irq, void *p) |
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{ |
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struct iio_poll_func *pf = p; |
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struct iio_dev *indio_dev = pf->indio_dev; |
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struct ad7766 *ad7766 = iio_priv(indio_dev); |
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int ret; |
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ret = spi_sync(ad7766->spi, &ad7766->msg); |
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if (ret < 0) |
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goto done; |
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iio_push_to_buffers_with_timestamp(indio_dev, ad7766->data, |
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pf->timestamp); |
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done: |
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iio_trigger_notify_done(indio_dev->trig); |
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return IRQ_HANDLED; |
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} |
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static int ad7766_preenable(struct iio_dev *indio_dev) |
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{ |
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struct ad7766 *ad7766 = iio_priv(indio_dev); |
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int ret; |
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ret = regulator_bulk_enable(ARRAY_SIZE(ad7766->reg), ad7766->reg); |
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if (ret < 0) { |
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dev_err(&ad7766->spi->dev, "Failed to enable supplies: %d\n", |
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ret); |
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return ret; |
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} |
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ret = clk_prepare_enable(ad7766->mclk); |
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if (ret < 0) { |
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dev_err(&ad7766->spi->dev, "Failed to enable MCLK: %d\n", ret); |
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regulator_bulk_disable(ARRAY_SIZE(ad7766->reg), ad7766->reg); |
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return ret; |
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} |
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gpiod_set_value(ad7766->pd_gpio, 0); |
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return 0; |
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} |
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static int ad7766_postdisable(struct iio_dev *indio_dev) |
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{ |
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struct ad7766 *ad7766 = iio_priv(indio_dev); |
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gpiod_set_value(ad7766->pd_gpio, 1); |
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/* |
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* The PD pin is synchronous to the clock, so give it some time to |
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* notice the change before we disable the clock. |
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*/ |
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msleep(20); |
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clk_disable_unprepare(ad7766->mclk); |
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regulator_bulk_disable(ARRAY_SIZE(ad7766->reg), ad7766->reg); |
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return 0; |
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} |
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static int ad7766_read_raw(struct iio_dev *indio_dev, |
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const struct iio_chan_spec *chan, int *val, int *val2, long info) |
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{ |
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struct ad7766 *ad7766 = iio_priv(indio_dev); |
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struct regulator *vref = ad7766->reg[AD7766_SUPPLY_VREF].consumer; |
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int scale_uv; |
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switch (info) { |
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case IIO_CHAN_INFO_SCALE: |
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scale_uv = regulator_get_voltage(vref); |
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if (scale_uv < 0) |
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return scale_uv; |
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*val = scale_uv / 1000; |
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*val2 = chan->scan_type.realbits; |
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return IIO_VAL_FRACTIONAL_LOG2; |
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case IIO_CHAN_INFO_SAMP_FREQ: |
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*val = clk_get_rate(ad7766->mclk) / |
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ad7766->chip_info->decimation_factor; |
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return IIO_VAL_INT; |
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} |
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return -EINVAL; |
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} |
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static const struct iio_chan_spec ad7766_channels[] = { |
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{ |
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.type = IIO_VOLTAGE, |
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.indexed = 1, |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), |
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.scan_type = { |
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.sign = 's', |
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.realbits = 24, |
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.storagebits = 32, |
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.endianness = IIO_BE, |
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}, |
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}, |
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IIO_CHAN_SOFT_TIMESTAMP(1), |
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}; |
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static const struct ad7766_chip_info ad7766_chip_info[] = { |
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[ID_AD7766] = { |
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.decimation_factor = 8, |
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}, |
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[ID_AD7766_1] = { |
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.decimation_factor = 16, |
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}, |
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[ID_AD7766_2] = { |
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.decimation_factor = 32, |
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}, |
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}; |
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static const struct iio_buffer_setup_ops ad7766_buffer_setup_ops = { |
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.preenable = &ad7766_preenable, |
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.postdisable = &ad7766_postdisable, |
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}; |
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static const struct iio_info ad7766_info = { |
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.read_raw = &ad7766_read_raw, |
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}; |
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static irqreturn_t ad7766_irq(int irq, void *private) |
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{ |
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iio_trigger_poll(private); |
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return IRQ_HANDLED; |
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} |
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static int ad7766_set_trigger_state(struct iio_trigger *trig, bool enable) |
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{ |
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struct ad7766 *ad7766 = iio_trigger_get_drvdata(trig); |
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if (enable) |
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enable_irq(ad7766->spi->irq); |
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else |
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disable_irq(ad7766->spi->irq); |
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return 0; |
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} |
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static const struct iio_trigger_ops ad7766_trigger_ops = { |
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.set_trigger_state = ad7766_set_trigger_state, |
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.validate_device = iio_trigger_validate_own_device, |
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}; |
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static int ad7766_probe(struct spi_device *spi) |
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{ |
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const struct spi_device_id *id = spi_get_device_id(spi); |
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struct iio_dev *indio_dev; |
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struct ad7766 *ad7766; |
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int ret; |
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ad7766)); |
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if (!indio_dev) |
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return -ENOMEM; |
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ad7766 = iio_priv(indio_dev); |
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ad7766->chip_info = &ad7766_chip_info[id->driver_data]; |
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ad7766->mclk = devm_clk_get(&spi->dev, "mclk"); |
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if (IS_ERR(ad7766->mclk)) |
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return PTR_ERR(ad7766->mclk); |
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ad7766->reg[AD7766_SUPPLY_AVDD].supply = "avdd"; |
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ad7766->reg[AD7766_SUPPLY_DVDD].supply = "dvdd"; |
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ad7766->reg[AD7766_SUPPLY_VREF].supply = "vref"; |
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ret = devm_regulator_bulk_get(&spi->dev, ARRAY_SIZE(ad7766->reg), |
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ad7766->reg); |
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if (ret) |
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return ret; |
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ad7766->pd_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown", |
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GPIOD_OUT_HIGH); |
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if (IS_ERR(ad7766->pd_gpio)) |
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return PTR_ERR(ad7766->pd_gpio); |
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indio_dev->name = spi_get_device_id(spi)->name; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->channels = ad7766_channels; |
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indio_dev->num_channels = ARRAY_SIZE(ad7766_channels); |
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indio_dev->info = &ad7766_info; |
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if (spi->irq > 0) { |
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ad7766->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d", |
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indio_dev->name, indio_dev->id); |
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if (!ad7766->trig) |
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return -ENOMEM; |
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ad7766->trig->ops = &ad7766_trigger_ops; |
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ad7766->trig->dev.parent = &spi->dev; |
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iio_trigger_set_drvdata(ad7766->trig, ad7766); |
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ret = devm_request_irq(&spi->dev, spi->irq, ad7766_irq, |
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IRQF_TRIGGER_FALLING, dev_name(&spi->dev), |
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ad7766->trig); |
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if (ret < 0) |
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return ret; |
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/* |
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* The device generates interrupts as long as it is powered up. |
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* Some platforms might not allow the option to power it down so |
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* disable the interrupt to avoid extra load on the system |
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*/ |
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disable_irq(spi->irq); |
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ret = devm_iio_trigger_register(&spi->dev, ad7766->trig); |
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if (ret) |
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return ret; |
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} |
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spi_set_drvdata(spi, indio_dev); |
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ad7766->spi = spi; |
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/* First byte always 0 */ |
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ad7766->xfer.rx_buf = &ad7766->data[1]; |
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ad7766->xfer.len = 3; |
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spi_message_init(&ad7766->msg); |
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spi_message_add_tail(&ad7766->xfer, &ad7766->msg); |
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ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, |
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&iio_pollfunc_store_time, &ad7766_trigger_handler, |
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&ad7766_buffer_setup_ops); |
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if (ret) |
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return ret; |
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ret = devm_iio_device_register(&spi->dev, indio_dev); |
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if (ret) |
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return ret; |
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return 0; |
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} |
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static const struct spi_device_id ad7766_id[] = { |
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{"ad7766", ID_AD7766}, |
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{"ad7766-1", ID_AD7766_1}, |
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{"ad7766-2", ID_AD7766_2}, |
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{"ad7767", ID_AD7766}, |
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{"ad7767-1", ID_AD7766_1}, |
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{"ad7767-2", ID_AD7766_2}, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(spi, ad7766_id); |
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static struct spi_driver ad7766_driver = { |
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.driver = { |
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.name = "ad7766", |
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}, |
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.probe = ad7766_probe, |
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.id_table = ad7766_id, |
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}; |
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module_spi_driver(ad7766_driver); |
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MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>"); |
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MODULE_DESCRIPTION("Analog Devices AD7766 and AD7767 ADCs driver support"); |
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MODULE_LICENSE("GPL v2");
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