--- /dev/null
+/*
+ * Analog devices AD5764, AD5764R, AD5744, AD5744R quad-channel
+ * Digital to Analog Converters driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/regulator/consumer.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define AD5764_REG_SF_NOP 0x0
+#define AD5764_REG_SF_CONFIG 0x1
+#define AD5764_REG_SF_CLEAR 0x4
+#define AD5764_REG_SF_LOAD 0x5
+#define AD5764_REG_DATA(x) ((2 << 3) | (x))
+#define AD5764_REG_COARSE_GAIN(x) ((3 << 3) | (x))
+#define AD5764_REG_FINE_GAIN(x) ((4 << 3) | (x))
+#define AD5764_REG_OFFSET(x) ((5 << 3) | (x))
+
+#define AD5764_NUM_CHANNELS 4
+
+/**
+ * struct ad5764_chip_info - chip specific information
+ * @int_vref: Value of the internal reference voltage in uV - 0 if external
+ * reference voltage is used
+ * @channel channel specification
+*/
+
+struct ad5764_chip_info {
+ unsigned long int_vref;
+ const struct iio_chan_spec *channels;
+};
+
+/**
+ * struct ad5764_state - driver instance specific data
+ * @spi: spi_device
+ * @chip_info: chip info
+ * @vref_reg: vref supply regulators
+ * @data: spi transfer buffers
+ */
+
+struct ad5764_state {
+ struct spi_device *spi;
+ const struct ad5764_chip_info *chip_info;
+ struct regulator_bulk_data vref_reg[2];
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ union {
+ __be32 d32;
+ u8 d8[4];
+ } data[2] ____cacheline_aligned;
+};
+
+enum ad5764_type {
+ ID_AD5744,
+ ID_AD5744R,
+ ID_AD5764,
+ ID_AD5764R,
+};
+
+#define AD5764_CHANNEL(_chan, _bits) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = (_chan), \
+ .address = (_chan), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_CALIBSCALE) | \
+ BIT(IIO_CHAN_INFO_CALIBBIAS), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = (_bits), \
+ .storagebits = 16, \
+ .shift = 16 - (_bits), \
+ }, \
+}
+
+#define DECLARE_AD5764_CHANNELS(_name, _bits) \
+const struct iio_chan_spec _name##_channels[] = { \
+ AD5764_CHANNEL(0, (_bits)), \
+ AD5764_CHANNEL(1, (_bits)), \
+ AD5764_CHANNEL(2, (_bits)), \
+ AD5764_CHANNEL(3, (_bits)), \
+};
+
+static DECLARE_AD5764_CHANNELS(ad5764, 16);
+static DECLARE_AD5764_CHANNELS(ad5744, 14);
+
+static const struct ad5764_chip_info ad5764_chip_infos[] = {
+ [ID_AD5744] = {
+ .int_vref = 0,
+ .channels = ad5744_channels,
+ },
+ [ID_AD5744R] = {
+ .int_vref = 5000000,
+ .channels = ad5744_channels,
+ },
+ [ID_AD5764] = {
+ .int_vref = 0,
+ .channels = ad5764_channels,
+ },
+ [ID_AD5764R] = {
+ .int_vref = 5000000,
+ .channels = ad5764_channels,
+ },
+};
+
+static int ad5764_write(struct iio_dev *indio_dev, unsigned int reg,
+ unsigned int val)
+{
+ struct ad5764_state *st = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&indio_dev->mlock);
+ st->data[0].d32 = cpu_to_be32((reg << 16) | val);
+
+ ret = spi_write(st->spi, &st->data[0].d8[1], 3);
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
+}
+
+static int ad5764_read(struct iio_dev *indio_dev, unsigned int reg,
+ unsigned int *val)
+{
+ struct ad5764_state *st = iio_priv(indio_dev);
+ int ret;
+ struct spi_transfer t[] = {
+ {
+ .tx_buf = &st->data[0].d8[1],
+ .len = 3,
+ .cs_change = 1,
+ }, {
+ .rx_buf = &st->data[1].d8[1],
+ .len = 3,
+ },
+ };
+
+ mutex_lock(&indio_dev->mlock);
+
+ st->data[0].d32 = cpu_to_be32((1 << 23) | (reg << 16));
+
+ ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
+ if (ret >= 0)
+ *val = be32_to_cpu(st->data[1].d32) & 0xffff;
+
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
+}
+
+static int ad5764_chan_info_to_reg(struct iio_chan_spec const *chan, long info)
+{
+ switch (info) {
+ case 0:
+ return AD5764_REG_DATA(chan->address);
+ case IIO_CHAN_INFO_CALIBBIAS:
+ return AD5764_REG_OFFSET(chan->address);
+ case IIO_CHAN_INFO_CALIBSCALE:
+ return AD5764_REG_FINE_GAIN(chan->address);
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int ad5764_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val, int val2, long info)
+{
+ const int max_val = (1 << chan->scan_type.realbits);
+ unsigned int reg;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ if (val >= max_val || val < 0)
+ return -EINVAL;
+ val <<= chan->scan_type.shift;
+ break;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ if (val >= 128 || val < -128)
+ return -EINVAL;
+ break;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ if (val >= 32 || val < -32)
+ return -EINVAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ reg = ad5764_chan_info_to_reg(chan, info);
+ return ad5764_write(indio_dev, reg, (u16)val);
+}
+
+static int ad5764_get_channel_vref(struct ad5764_state *st,
+ unsigned int channel)
+{
+ if (st->chip_info->int_vref)
+ return st->chip_info->int_vref;
+ else
+ return regulator_get_voltage(st->vref_reg[channel / 2].consumer);
+}
+
+static int ad5764_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val, int *val2, long info)
+{
+ struct ad5764_state *st = iio_priv(indio_dev);
+ unsigned int reg;
+ int vref;
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ reg = AD5764_REG_DATA(chan->address);
+ ret = ad5764_read(indio_dev, reg, val);
+ if (ret < 0)
+ return ret;
+ *val >>= chan->scan_type.shift;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ reg = AD5764_REG_OFFSET(chan->address);
+ ret = ad5764_read(indio_dev, reg, val);
+ if (ret < 0)
+ return ret;
+ *val = sign_extend32(*val, 7);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ reg = AD5764_REG_FINE_GAIN(chan->address);
+ ret = ad5764_read(indio_dev, reg, val);
+ if (ret < 0)
+ return ret;
+ *val = sign_extend32(*val, 5);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ /* vout = 4 * vref + ((dac_code / 65536) - 0.5) */
+ vref = ad5764_get_channel_vref(st, chan->channel);
+ if (vref < 0)
+ return vref;
+
+ *val = vref * 4 / 1000;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = -(1 << chan->scan_type.realbits) / 2;
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info ad5764_info = {
+ .read_raw = ad5764_read_raw,
+ .write_raw = ad5764_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int ad5764_probe(struct spi_device *spi)
+{
+ enum ad5764_type type = spi_get_device_id(spi)->driver_data;
+ struct iio_dev *indio_dev;
+ struct ad5764_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (indio_dev == NULL) {
+ dev_err(&spi->dev, "Failed to allocate iio device\n");
+ return -ENOMEM;
+ }
+
+ st = iio_priv(indio_dev);
+ spi_set_drvdata(spi, indio_dev);
+
+ st->spi = spi;
+ st->chip_info = &ad5764_chip_infos[type];
+
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->info = &ad5764_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->num_channels = AD5764_NUM_CHANNELS;
+ indio_dev->channels = st->chip_info->channels;
+
+ if (st->chip_info->int_vref == 0) {
+ st->vref_reg[0].supply = "vrefAB";
+ st->vref_reg[1].supply = "vrefCD";
+
+ ret = devm_regulator_bulk_get(&st->spi->dev,
+ ARRAY_SIZE(st->vref_reg), st->vref_reg);
+ if (ret) {
+ dev_err(&spi->dev, "Failed to request vref regulators: %d\n",
+ ret);
+ return ret;
+ }
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(st->vref_reg),
+ st->vref_reg);
+ if (ret) {
+ dev_err(&spi->dev, "Failed to enable vref regulators: %d\n",
+ ret);
+ return ret;
+ }
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err(&spi->dev, "Failed to register iio device: %d\n", ret);
+ goto error_disable_reg;
+ }
+
+ return 0;
+
+error_disable_reg:
+ if (st->chip_info->int_vref == 0)
+ regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg);
+ return ret;
+}
+
+static int ad5764_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ad5764_state *st = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ if (st->chip_info->int_vref == 0)
+ regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg);
+
+ return 0;
+}
+
+static const struct spi_device_id ad5764_ids[] = {
+ { "ad5744", ID_AD5744 },
+ { "ad5744r", ID_AD5744R },
+ { "ad5764", ID_AD5764 },
+ { "ad5764r", ID_AD5764R },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ad5764_ids);
+
+static struct spi_driver ad5764_driver = {
+ .driver = {
+ .name = "ad5764",
+ .owner = THIS_MODULE,
+ },
+ .probe = ad5764_probe,
+ .remove = ad5764_remove,
+ .id_table = ad5764_ids,
+};
+module_spi_driver(ad5764_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Devices AD5744/AD5744R/AD5764/AD5764R DAC");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff