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