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Diffstat (limited to 'drivers/iio/adc/ad7476.c')
-rw-r--r--drivers/iio/adc/ad7476.c455
1 files changed, 455 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c
new file mode 100644
index 0000000000..80aebed47d
--- /dev/null
+++ b/drivers/iio/adc/ad7476.c
@@ -0,0 +1,455 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Analog Devices AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
+ * TI ADC081S/ADC101S/ADC121S 8/10/12-bit SPI ADC driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ */
+
+#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/gpio/consumer.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/delay.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];
+ /* channels used when convst gpio is defined */
+ struct iio_chan_spec convst_channel[2];
+ void (*reset)(struct ad7476_state *);
+ bool has_vref;
+ bool has_vdrive;
+};
+
+struct ad7476_state {
+ struct spi_device *spi;
+ const struct ad7476_chip_info *chip_info;
+ struct regulator *ref_reg;
+ struct gpio_desc *convst_gpio;
+ struct spi_transfer xfer;
+ struct spi_message msg;
+ /*
+ * DMA (thus cache coherency maintenance) may require 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)] __aligned(IIO_DMA_MINALIGN);
+};
+
+enum ad7476_supported_device_ids {
+ ID_AD7091,
+ ID_AD7091R,
+ ID_AD7273,
+ ID_AD7274,
+ ID_AD7276,
+ ID_AD7277,
+ ID_AD7278,
+ ID_AD7466,
+ ID_AD7467,
+ ID_AD7468,
+ ID_AD7475,
+ ID_AD7495,
+ ID_AD7940,
+ ID_ADC081S,
+ ID_ADC101S,
+ ID_ADC121S,
+ ID_ADS7866,
+ ID_ADS7867,
+ ID_ADS7868,
+ ID_LTC2314_14,
+};
+
+static void ad7091_convst(struct ad7476_state *st)
+{
+ if (!st->convst_gpio)
+ return;
+
+ gpiod_set_value(st->convst_gpio, 0);
+ udelay(1); /* CONVST pulse width: 10 ns min */
+ gpiod_set_value(st->convst_gpio, 1);
+ udelay(1); /* Conversion time: 650 ns max */
+}
+
+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;
+
+ ad7091_convst(st);
+
+ 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;
+
+ ad7091_convst(st);
+
+ 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->ref_reg) {
+ scale_uv = regulator_get_voltage(st->ref_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 ADC081S_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \
+ BIT(IIO_CHAN_INFO_RAW))
+#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)
+#define AD7091R_CONVST_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), \
+ BIT(IIO_CHAN_INFO_RAW))
+#define ADS786X_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \
+ BIT(IIO_CHAN_INFO_RAW))
+
+static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
+ [ID_AD7091] = {
+ .channel[0] = AD7091R_CHAN(12),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .convst_channel[0] = AD7091R_CONVST_CHAN(12),
+ .convst_channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .reset = ad7091_reset,
+ },
+ [ID_AD7091R] = {
+ .channel[0] = AD7091R_CHAN(12),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .convst_channel[0] = AD7091R_CONVST_CHAN(12),
+ .convst_channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .int_vref_uv = 2500000,
+ .has_vref = true,
+ .reset = ad7091_reset,
+ },
+ [ID_AD7273] = {
+ .channel[0] = AD7940_CHAN(10),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .has_vref = true,
+ },
+ [ID_AD7274] = {
+ .channel[0] = AD7940_CHAN(12),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .has_vref = true,
+ },
+ [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_AD7475] = {
+ .channel[0] = AD7476_CHAN(12),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .has_vref = true,
+ .has_vdrive = true,
+ },
+ [ID_AD7495] = {
+ .channel[0] = AD7476_CHAN(12),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .int_vref_uv = 2500000,
+ .has_vdrive = true,
+ },
+ [ID_AD7940] = {
+ .channel[0] = AD7940_CHAN(14),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ },
+ [ID_ADC081S] = {
+ .channel[0] = ADC081S_CHAN(8),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ },
+ [ID_ADC101S] = {
+ .channel[0] = ADC081S_CHAN(10),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ },
+ [ID_ADC121S] = {
+ .channel[0] = ADC081S_CHAN(12),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ },
+ [ID_ADS7866] = {
+ .channel[0] = ADS786X_CHAN(12),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ },
+ [ID_ADS7867] = {
+ .channel[0] = ADS786X_CHAN(10),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ },
+ [ID_ADS7868] = {
+ .channel[0] = ADS786X_CHAN(8),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ },
+ [ID_LTC2314_14] = {
+ .channel[0] = AD7940_CHAN(14),
+ .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+ .has_vref = true,
+ },
+};
+
+static const struct iio_info ad7476_info = {
+ .read_raw = &ad7476_read_raw,
+};
+
+static void ad7476_reg_disable(void *data)
+{
+ struct regulator *reg = data;
+
+ regulator_disable(reg);
+}
+
+static int ad7476_probe(struct spi_device *spi)
+{
+ struct ad7476_state *st;
+ struct iio_dev *indio_dev;
+ struct regulator *reg;
+ 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];
+
+ reg = devm_regulator_get(&spi->dev, "vcc");
+ if (IS_ERR(reg))
+ return PTR_ERR(reg);
+
+ ret = regulator_enable(reg);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(&spi->dev, ad7476_reg_disable, reg);
+ if (ret)
+ return ret;
+
+ /* Either vcc or vref (below) as appropriate */
+ if (!st->chip_info->int_vref_uv)
+ st->ref_reg = reg;
+
+ if (st->chip_info->has_vref) {
+
+ /* If a device has an internal reference vref is optional */
+ if (st->chip_info->int_vref_uv) {
+ reg = devm_regulator_get_optional(&spi->dev, "vref");
+ if (IS_ERR(reg) && (PTR_ERR(reg) != -ENODEV))
+ return PTR_ERR(reg);
+ } else {
+ reg = devm_regulator_get(&spi->dev, "vref");
+ if (IS_ERR(reg))
+ return PTR_ERR(reg);
+ }
+
+ if (!IS_ERR(reg)) {
+ ret = regulator_enable(reg);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(&spi->dev,
+ ad7476_reg_disable,
+ reg);
+ if (ret)
+ return ret;
+ st->ref_reg = reg;
+ } else {
+ /*
+ * Can only get here if device supports both internal
+ * and external reference, but the regulator connected
+ * to the external reference is not connected.
+ * Set the reference regulator pointer to NULL to
+ * indicate this.
+ */
+ st->ref_reg = NULL;
+ }
+ }
+
+ if (st->chip_info->has_vdrive) {
+ ret = devm_regulator_get_enable(&spi->dev, "vdrive");
+ if (ret)
+ return ret;
+ }
+
+ st->convst_gpio = devm_gpiod_get_optional(&spi->dev,
+ "adi,conversion-start",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(st->convst_gpio))
+ return PTR_ERR(st->convst_gpio);
+
+ st->spi = spi;
+
+ 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;
+
+ if (st->convst_gpio)
+ indio_dev->channels = st->chip_info->convst_channel;
+ /* 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 = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
+ &ad7476_trigger_handler, NULL);
+ if (ret)
+ return ret;
+
+ if (st->chip_info->reset)
+ st->chip_info->reset(st);
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ad7476_id[] = {
+ {"ad7091", ID_AD7091},
+ {"ad7091r", ID_AD7091R},
+ {"ad7273", ID_AD7273},
+ {"ad7274", ID_AD7274},
+ {"ad7276", ID_AD7276},
+ {"ad7277", ID_AD7277},
+ {"ad7278", ID_AD7278},
+ {"ad7466", ID_AD7466},
+ {"ad7467", ID_AD7467},
+ {"ad7468", ID_AD7468},
+ {"ad7475", ID_AD7475},
+ {"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},
+ {"adc081s", ID_ADC081S},
+ {"adc101s", ID_ADC101S},
+ {"adc121s", ID_ADC121S},
+ {"ads7866", ID_ADS7866},
+ {"ads7867", ID_ADS7867},
+ {"ads7868", ID_ADS7868},
+ {"ltc2314-14", ID_LTC2314_14},
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad7476_id);
+
+static struct spi_driver ad7476_driver = {
+ .driver = {
+ .name = "ad7476",
+ },
+ .probe = ad7476_probe,
+ .id_table = ad7476_id,
+};
+module_spi_driver(ad7476_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
+MODULE_LICENSE("GPL v2");