iio:dac: Add support for the ad5449
authorLars-Peter Clausen <lars@metafoo.de>
Tue, 16 Oct 2012 16:29:00 +0000 (17:29 +0100)
committerJonathan Cameron <jic23@kernel.org>
Fri, 19 Oct 2012 17:46:51 +0000 (18:46 +0100)
This patch adds support for the AD5415, AD5426, AD5429, AD5432, AD5439, AD5443
and AD5449 single and dual channel DACs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/dac/Kconfig
drivers/iio/dac/Makefile
drivers/iio/dac/ad5449.c [new file with mode: 0644]
include/linux/platform_data/ad5449.h [new file with mode: 0644]

index b1c0ee5..f68756e 100644 (file)
@@ -67,6 +67,16 @@ config AD5446
          To compile this driver as a module, choose M here: the
          module will be called ad5446.
 
+config AD5449
+       tristate "Analog Device AD5449 and similar DACs driver"
+       depends on SPI_MASTER
+       help
+         Say yes here to build support for Analog Devices AD5415, AD5426, AD5429,
+         AD5432, AD5439, AD5443, AD5449 Digital to Analog Converters.
+
+         To compile this driver as a module, choose M here: the
+         module will be called ad5449.
+
 config AD5504
        tristate "Analog Devices AD5504/AD5501 DAC SPI driver"
        depends on SPI
index c0d333b..5b528eb 100644 (file)
@@ -9,6 +9,7 @@ obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
 obj-$(CONFIG_AD5064) += ad5064.o
 obj-$(CONFIG_AD5504) += ad5504.o
 obj-$(CONFIG_AD5446) += ad5446.o
+obj-$(CONFIG_AD5449) += ad5449.o
 obj-$(CONFIG_AD5755) += ad5755.o
 obj-$(CONFIG_AD5764) += ad5764.o
 obj-$(CONFIG_AD5791) += ad5791.o
diff --git a/drivers/iio/dac/ad5449.c b/drivers/iio/dac/ad5449.c
new file mode 100644 (file)
index 0000000..5b43030
--- /dev/null
@@ -0,0 +1,375 @@
+/*
+ * 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");
diff --git a/include/linux/platform_data/ad5449.h b/include/linux/platform_data/ad5449.h
new file mode 100644 (file)
index 0000000..bd712bd
--- /dev/null
@@ -0,0 +1,40 @@
+/*
+ * 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.
+ */
+
+#ifndef __LINUX_PLATFORM_DATA_AD5449_H__
+#define __LINUX_PLATFORM_DATA_AD5449_H__
+
+/**
+ * enum ad5449_sdo_mode - AD5449 SDO pin configuration
+ * @AD5449_SDO_DRIVE_FULL: Drive the SDO pin with full strength.
+ * @AD5449_SDO_DRIVE_WEAK: Drive the SDO pin with not full strength.
+ * @AD5449_SDO_OPEN_DRAIN: Operate the SDO pin in open-drain mode.
+ * @AD5449_SDO_DISABLED: Disable the SDO pin, in this mode it is not possible to
+ *                     read back from the device.
+ */
+enum ad5449_sdo_mode {
+       AD5449_SDO_DRIVE_FULL = 0x0,
+       AD5449_SDO_DRIVE_WEAK = 0x1,
+       AD5449_SDO_OPEN_DRAIN = 0x2,
+       AD5449_SDO_DISABLED = 0x3,
+};
+
+/**
+ * struct ad5449_platform_data - Platform data for the ad5449 DAC driver
+ * @sdo_mode: SDO pin mode
+ * @hardware_clear_to_midscale: Whether asserting the hardware CLR pin sets the
+ *                     outputs to midscale (true) or to zero scale(false).
+ */
+struct ad5449_platform_data {
+       enum ad5449_sdo_mode sdo_mode;
+       bool hardware_clear_to_midscale;
+};
+
+#endif