316 lines
7.5 KiB
C
316 lines
7.5 KiB
C
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// 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) may require 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)] __aligned(IIO_DMA_MINALIGN);
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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,
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iio_device_id(indio_dev));
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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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iio_trigger_set_drvdata(ad7766->trig, ad7766);
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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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* don't enable the interrupt to avoid extra load on the system
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*/
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ret = devm_request_irq(&spi->dev, spi->irq, ad7766_irq,
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IRQF_TRIGGER_FALLING | IRQF_NO_AUTOEN,
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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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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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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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return devm_iio_device_register(&spi->dev, indio_dev);
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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 <lars@metafoo.de>");
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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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