--- /dev/null
+/*
+ * AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog
+ * Converter driver.
+ *
+ * Copyright 2012 Analog Devices Inc.
+ * Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * 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 <asm/unaligned.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include <linux/platform_data/ad5449.h>
+
+#define AD5449_MAX_CHANNELS 2
+#define AD5449_MAX_VREFS 2
+
+#define AD5449_CMD_NOOP 0x0
+#define AD5449_CMD_LOAD_AND_UPDATE(x) (0x1 + (x) * 3)
+#define AD5449_CMD_READ(x) (0x2 + (x) * 3)
+#define AD5449_CMD_LOAD(x) (0x3 + (x) * 3)
+#define AD5449_CMD_CTRL 13
+
+#define AD5449_CTRL_SDO_OFFSET 10
+#define AD5449_CTRL_DAISY_CHAIN BIT(9)
+#define AD5449_CTRL_HCLR_TO_MIDSCALE BIT(8)
+#define AD5449_CTRL_SAMPLE_RISING BIT(7)
+
+/**
+ * struct ad5449_chip_info - chip specific information
+ * @channels: Channel specification
+ * @num_channels: Number of channels
+ * @has_ctrl: Chip has a control register
+ */
+struct ad5449_chip_info {
+ const struct iio_chan_spec *channels;
+ unsigned int num_channels;
+ bool has_ctrl;
+};
+
+/**
+ * struct ad5449 - driver instance specific data
+ * @spi: the SPI device for this driver instance
+ * @chip_info: chip model specific constants, available modes etc
+ * @vref_reg: vref supply regulators
+ * @has_sdo: whether the SDO line is connected
+ * @dac_cache: Cache for the DAC values
+ * @data: spi transfer buffers
+ */
+struct ad5449 {
+ struct spi_device *spi;
+ const struct ad5449_chip_info *chip_info;
+ struct regulator_bulk_data vref_reg[AD5449_MAX_VREFS];
+
+ bool has_sdo;
+ uint16_t dac_cache[AD5449_MAX_CHANNELS];
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ __be16 data[2] ____cacheline_aligned;
+};
+
+enum ad5449_type {
+ ID_AD5426,
+ ID_AD5429,
+ ID_AD5432,
+ ID_AD5439,
+ ID_AD5443,
+ ID_AD5449,
+};
+
+static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr,
+ unsigned int val)
+{
+ struct ad5449 *st = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&indio_dev->mlock);
+ st->data[0] = cpu_to_be16((addr << 12) | val);
+ ret = spi_write(st->spi, st->data, 2);
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
+}
+
+static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr,
+ unsigned int *val)
+{
+ struct ad5449 *st = iio_priv(indio_dev);
+ int ret;
+ struct spi_message msg;
+ struct spi_transfer t[] = {
+ {
+ .tx_buf = &st->data[0],
+ .len = 2,
+ .cs_change = 1,
+ }, {
+ .tx_buf = &st->data[1],
+ .rx_buf = &st->data[1],
+ .len = 2,
+ },
+ };
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&t[0], &msg);
+ spi_message_add_tail(&t[1], &msg);
+
+ mutex_lock(&indio_dev->mlock);
+ st->data[0] = cpu_to_be16(addr << 12);
+ st->data[1] = cpu_to_be16(AD5449_CMD_NOOP);
+
+ ret = spi_sync(st->spi, &msg);
+ if (ret < 0)
+ return ret;
+
+ *val = be16_to_cpu(st->data[1]);
+ mutex_unlock(&indio_dev->mlock);
+
+ return 0;
+}
+
+static int ad5449_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val, int *val2, long info)
+{
+ struct ad5449 *st = iio_priv(indio_dev);
+ struct regulator_bulk_data *reg;
+ int scale_uv;
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ if (st->has_sdo) {
+ ret = ad5449_read(indio_dev,
+ AD5449_CMD_READ(chan->address), val);
+ if (ret)
+ return ret;
+ *val &= 0xfff;
+ } else {
+ *val = st->dac_cache[chan->address];
+ }
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ reg = &st->vref_reg[chan->channel];
+ scale_uv = regulator_get_voltage(reg->consumer);
+ if (scale_uv < 0)
+ return scale_uv;
+
+ *val = scale_uv / 1000;
+ *val2 = chan->scan_type.realbits;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+static int ad5449_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val, int val2, long info)
+{
+ struct ad5449 *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ if (val < 0 || val >= (1 << chan->scan_type.realbits))
+ return -EINVAL;
+
+ ret = ad5449_write(indio_dev,
+ AD5449_CMD_LOAD_AND_UPDATE(chan->address),
+ val << chan->scan_type.shift);
+ if (ret == 0)
+ st->dac_cache[chan->address] = val;
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static const struct iio_info ad5449_info = {
+ .read_raw = ad5449_read_raw,
+ .write_raw = ad5449_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+#define AD5449_CHANNEL(chan, bits) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = (chan), \
+ .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
+ IIO_CHAN_INFO_SCALE_SEPARATE_BIT, \
+ .address = (chan), \
+ .scan_type = IIO_ST('u', (bits), 16, 12 - (bits)), \
+}
+
+#define DECLARE_AD5449_CHANNELS(name, bits) \
+const struct iio_chan_spec name[] = { \
+ AD5449_CHANNEL(0, bits), \
+ AD5449_CHANNEL(1, bits), \
+}
+
+static DECLARE_AD5449_CHANNELS(ad5429_channels, 8);
+static DECLARE_AD5449_CHANNELS(ad5439_channels, 10);
+static DECLARE_AD5449_CHANNELS(ad5449_channels, 12);
+
+static const struct ad5449_chip_info ad5449_chip_info[] = {
+ [ID_AD5426] = {
+ .channels = ad5429_channels,
+ .num_channels = 1,
+ .has_ctrl = false,
+ },
+ [ID_AD5429] = {
+ .channels = ad5429_channels,
+ .num_channels = 2,
+ .has_ctrl = true,
+ },
+ [ID_AD5432] = {
+ .channels = ad5439_channels,
+ .num_channels = 1,
+ .has_ctrl = false,
+ },
+ [ID_AD5439] = {
+ .channels = ad5439_channels,
+ .num_channels = 2,
+ .has_ctrl = true,
+ },
+ [ID_AD5443] = {
+ .channels = ad5449_channels,
+ .num_channels = 1,
+ .has_ctrl = false,
+ },
+ [ID_AD5449] = {
+ .channels = ad5449_channels,
+ .num_channels = 2,
+ .has_ctrl = true,
+ },
+};
+
+static const char *ad5449_vref_name(struct ad5449 *st, int n)
+{
+ if (st->chip_info->num_channels == 1)
+ return "VREF";
+
+ if (n == 0)
+ return "VREFA";
+ else
+ return "VREFB";
+}
+
+static int __devinit ad5449_spi_probe(struct spi_device *spi)
+{
+ struct ad5449_platform_data *pdata = spi->dev.platform_data;
+ const struct spi_device_id *id = spi_get_device_id(spi);
+ struct iio_dev *indio_dev;
+ struct ad5449 *st;
+ unsigned int i;
+ int ret;
+
+ indio_dev = iio_device_alloc(sizeof(*st));
+ if (indio_dev == NULL)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ spi_set_drvdata(spi, indio_dev);
+
+ st->chip_info = &ad5449_chip_info[id->driver_data];
+ st->spi = spi;
+
+ for (i = 0; i < st->chip_info->num_channels; ++i)
+ st->vref_reg[i].supply = ad5449_vref_name(st, i);
+
+ ret = regulator_bulk_get(&spi->dev, st->chip_info->num_channels,
+ st->vref_reg);
+ if (ret)
+ goto error_free;
+
+ ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg);
+ if (ret)
+ goto error_free_reg;
+
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->name = id->name;
+ indio_dev->info = &ad5449_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = st->chip_info->channels;
+ indio_dev->num_channels = st->chip_info->num_channels;
+
+ if (st->chip_info->has_ctrl) {
+ unsigned int ctrl = 0x00;
+ if (pdata) {
+ if (pdata->hardware_clear_to_midscale)
+ ctrl |= AD5449_CTRL_HCLR_TO_MIDSCALE;
+ ctrl |= pdata->sdo_mode << AD5449_CTRL_SDO_OFFSET;
+ st->has_sdo = pdata->sdo_mode != AD5449_SDO_DISABLED;
+ } else {
+ st->has_sdo = true;
+ }
+ ad5449_write(indio_dev, AD5449_CMD_CTRL, ctrl);
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_disable_reg;
+
+ return 0;
+
+error_disable_reg:
+ regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);
+error_free_reg:
+ regulator_bulk_free(st->chip_info->num_channels, st->vref_reg);
+error_free:
+ iio_device_free(indio_dev);
+
+ return ret;
+}
+
+static int __devexit ad5449_spi_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ad5449 *st = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);
+ regulator_bulk_free(st->chip_info->num_channels, st->vref_reg);
+
+ iio_device_free(indio_dev);
+
+ return 0;
+}
+
+static const struct spi_device_id ad5449_spi_ids[] = {
+ { "ad5415", ID_AD5449 },
+ { "ad5426", ID_AD5426 },
+ { "ad5429", ID_AD5429 },
+ { "ad5432", ID_AD5432 },
+ { "ad5439", ID_AD5439 },
+ { "ad5443", ID_AD5443 },
+ { "ad5449", ID_AD5449 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad5449_spi_ids);
+
+static struct spi_driver ad5449_spi_driver = {
+ .driver = {
+ .name = "ad5449",
+ .owner = THIS_MODULE,
+ },
+ .probe = ad5449_spi_probe,
+ .remove = __devexit_p(ad5449_spi_remove),
+ .id_table = ad5449_spi_ids,
+};
+module_spi_driver(ad5449_spi_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs");
+MODULE_LICENSE("GPL v2");
projects / cascardo / linux.git / commitdiff