/* * AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver * * Copyright 2010 Analog Devices Inc. * * Licensed under the GPL-2 or later. */ #include <linux/device.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/sysfs.h> #include <linux/spi/spi.h> #include <linux/regulator/consumer.h> #include <linux/err.h> #include <linux/module.h> #include <linux/bitops.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #include <linux/iio/buffer.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> struct ad7476_state; struct ad7476_chip_info { unsigned int int_vref_uv; struct iio_chan_spec channel[2]; void (*reset)(struct ad7476_state *); }; struct ad7476_state { struct spi_device *spi; const struct ad7476_chip_info *chip_info; struct regulator *reg; 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 16 bit sample and one 64 bit * aligned 64 bit timestamp. */ unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)] ____cacheline_aligned; }; enum ad7476_supported_device_ids { ID_AD7091R, ID_AD7276, ID_AD7277, ID_AD7278, ID_AD7466, ID_AD7467, ID_AD7468, ID_AD7495, ID_AD7940, }; static irqreturn_t ad7476_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct ad7476_state *st = iio_priv(indio_dev); int b_sent; b_sent = spi_sync(st->spi, &st->msg); if (b_sent < 0) goto done; iio_push_to_buffers_with_timestamp(indio_dev, st->data, iio_get_time_ns(indio_dev)); done: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static void ad7091_reset(struct ad7476_state *st) { /* Any transfers with 8 scl cycles will reset the device */ spi_read(st->spi, st->data, 1); } static int ad7476_scan_direct(struct ad7476_state *st) { int ret; ret = spi_sync(st->spi, &st->msg); if (ret) return ret; return be16_to_cpup((__be16 *)st->data); } static int ad7476_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long m) { int ret; struct ad7476_state *st = iio_priv(indio_dev); int scale_uv; switch (m) { case IIO_CHAN_INFO_RAW: ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; ret = ad7476_scan_direct(st); iio_device_release_direct_mode(indio_dev); if (ret < 0) return ret; *val = (ret >> st->chip_info->channel[0].scan_type.shift) & GENMASK(st->chip_info->channel[0].scan_type.realbits - 1, 0); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: if (!st->chip_info->int_vref_uv) { scale_uv = regulator_get_voltage(st->reg); if (scale_uv < 0) return scale_uv; } else { scale_uv = st->chip_info->int_vref_uv; } *val = scale_uv / 1000; *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; } return -EINVAL; } #define _AD7476_CHAN(bits, _shift, _info_mask_sep) \ { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .info_mask_separate = _info_mask_sep, \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .scan_type = { \ .sign = 'u', \ .realbits = (bits), \ .storagebits = 16, \ .shift = (_shift), \ .endianness = IIO_BE, \ }, \ } #define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \ BIT(IIO_CHAN_INFO_RAW)) #define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \ BIT(IIO_CHAN_INFO_RAW)) #define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0) static const struct ad7476_chip_info ad7476_chip_info_tbl[] = { [ID_AD7091R] = { .channel[0] = AD7091R_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .reset = ad7091_reset, }, [ID_AD7276] = { .channel[0] = AD7940_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7277] = { .channel[0] = AD7940_CHAN(10), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7278] = { .channel[0] = AD7940_CHAN(8), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7466] = { .channel[0] = AD7476_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7467] = { .channel[0] = AD7476_CHAN(10), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7468] = { .channel[0] = AD7476_CHAN(8), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, [ID_AD7495] = { .channel[0] = AD7476_CHAN(12), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), .int_vref_uv = 2500000, }, [ID_AD7940] = { .channel[0] = AD7940_CHAN(14), .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), }, }; static const struct iio_info ad7476_info = { .driver_module = THIS_MODULE, .read_raw = &ad7476_read_raw, }; static int ad7476_probe(struct spi_device *spi) { struct ad7476_state *st; struct iio_dev *indio_dev; int ret; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); st->chip_info = &ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data]; st->reg = devm_regulator_get(&spi->dev, "vcc"); if (IS_ERR(st->reg)) return PTR_ERR(st->reg); ret = regulator_enable(st->reg); if (ret) return ret; spi_set_drvdata(spi, indio_dev); st->spi = spi; /* Establish that the iio_dev is a child of the spi device */ indio_dev->dev.parent = &spi->dev; indio_dev->dev.of_node = spi->dev.of_node; indio_dev->name = spi_get_device_id(spi)->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = st->chip_info->channel; indio_dev->num_channels = 2; indio_dev->info = &ad7476_info; /* Setup default message */ st->xfer.rx_buf = &st->data; st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8; spi_message_init(&st->msg); spi_message_add_tail(&st->xfer, &st->msg); ret = iio_triggered_buffer_setup(indio_dev, NULL, &ad7476_trigger_handler, NULL); if (ret) goto error_disable_reg; if (st->chip_info->reset) st->chip_info->reset(st); ret = iio_device_register(indio_dev); if (ret) goto error_ring_unregister; return 0; error_ring_unregister: iio_triggered_buffer_cleanup(indio_dev); error_disable_reg: regulator_disable(st->reg); return ret; } static int ad7476_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); struct ad7476_state *st = iio_priv(indio_dev); iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); regulator_disable(st->reg); return 0; } static const struct spi_device_id ad7476_id[] = { {"ad7091r", ID_AD7091R}, {"ad7273", ID_AD7277}, {"ad7274", ID_AD7276}, {"ad7276", ID_AD7276}, {"ad7277", ID_AD7277}, {"ad7278", ID_AD7278}, {"ad7466", ID_AD7466}, {"ad7467", ID_AD7467}, {"ad7468", ID_AD7468}, {"ad7475", ID_AD7466}, {"ad7476", ID_AD7466}, {"ad7476a", ID_AD7466}, {"ad7477", ID_AD7467}, {"ad7477a", ID_AD7467}, {"ad7478", ID_AD7468}, {"ad7478a", ID_AD7468}, {"ad7495", ID_AD7495}, {"ad7910", ID_AD7467}, {"ad7920", ID_AD7466}, {"ad7940", ID_AD7940}, {} }; MODULE_DEVICE_TABLE(spi, ad7476_id); static struct spi_driver ad7476_driver = { .driver = { .name = "ad7476", }, .probe = ad7476_probe, .remove = ad7476_remove, .id_table = ad7476_id, }; module_spi_driver(ad7476_driver); MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs"); MODULE_LICENSE("GPL v2");