Initial import

1 files changed, 408 insertions, 0 deletions

diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
new file mode 100644
index 000000000..15c73e202
--- /dev/null
+++ b/drivers/iio/dac/ad5686.c
@@ -0,0 +1,408 @@
+/*
+ * AD5686R, AD5685R, AD5684R Digital to analog converters  driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/device.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 AD5686_DAC_CHANNELS			4
+
+#define AD5686_ADDR(x)				((x) << 16)
+#define AD5686_CMD(x)				((x) << 20)
+
+#define AD5686_ADDR_DAC(chan)		(0x1 << (chan))
+#define AD5686_ADDR_ALL_DAC			0xF
+
+#define AD5686_CMD_NOOP				0x0
+#define AD5686_CMD_WRITE_INPUT_N		0x1
+#define AD5686_CMD_UPDATE_DAC_N			0x2
+#define AD5686_CMD_WRITE_INPUT_N_UPDATE_N	0x3
+#define AD5686_CMD_POWERDOWN_DAC		0x4
+#define AD5686_CMD_LDAC_MASK			0x5
+#define AD5686_CMD_RESET			0x6
+#define AD5686_CMD_INTERNAL_REFER_SETUP		0x7
+#define AD5686_CMD_DAISY_CHAIN_ENABLE		0x8
+#define AD5686_CMD_READBACK_ENABLE		0x9
+
+#define AD5686_LDAC_PWRDN_NONE			0x0
+#define AD5686_LDAC_PWRDN_1K			0x1
+#define AD5686_LDAC_PWRDN_100K			0x2
+#define AD5686_LDAC_PWRDN_3STATE		0x3
+
+/**
+ * struct ad5686_chip_info - chip specific information
+ * @int_vref_mv:	AD5620/40/60: the internal reference voltage
+ * @channel:		channel specification
+*/
+
+struct ad5686_chip_info {
+	u16				int_vref_mv;
+	struct iio_chan_spec		channel[AD5686_DAC_CHANNELS];
+};
+
+/**
+ * struct ad5446_state - driver instance specific data
+ * @spi:		spi_device
+ * @chip_info:		chip model specific constants, available modes etc
+ * @reg:		supply regulator
+ * @vref_mv:		actual reference voltage used
+ * @pwr_down_mask:	power down mask
+ * @pwr_down_mode:	current power down mode
+ * @data:		spi transfer buffers
+ */
+
+struct ad5686_state {
+	struct spi_device		*spi;
+	const struct ad5686_chip_info	*chip_info;
+	struct regulator		*reg;
+	unsigned short			vref_mv;
+	unsigned			pwr_down_mask;
+	unsigned			pwr_down_mode;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+
+	union {
+		__be32 d32;
+		u8 d8[4];
+	} data[3] ____cacheline_aligned;
+};
+
+/**
+ * ad5686_supported_device_ids:
+ */
+
+enum ad5686_supported_device_ids {
+	ID_AD5684,
+	ID_AD5685,
+	ID_AD5686,
+};
+static int ad5686_spi_write(struct ad5686_state *st,
+			     u8 cmd, u8 addr, u16 val, u8 shift)
+{
+	val <<= shift;
+
+	st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
+			      AD5686_ADDR(addr) |
+			      val);
+
+	return spi_write(st->spi, &st->data[0].d8[1], 3);
+}
+
+static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
+{
+	struct spi_transfer t[] = {
+		{
+			.tx_buf = &st->data[0].d8[1],
+			.len = 3,
+			.cs_change = 1,
+		}, {
+			.tx_buf = &st->data[1].d8[1],
+			.rx_buf = &st->data[2].d8[1],
+			.len = 3,
+		},
+	};
+	int ret;
+
+	st->data[0].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_READBACK_ENABLE) |
+			      AD5686_ADDR(addr));
+	st->data[1].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP));
+
+	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
+	if (ret < 0)
+		return ret;
+
+	return be32_to_cpu(st->data[2].d32);
+}
+
+static const char * const ad5686_powerdown_modes[] = {
+	"1kohm_to_gnd",
+	"100kohm_to_gnd",
+	"three_state"
+};
+
+static int ad5686_get_powerdown_mode(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan)
+{
+	struct ad5686_state *st = iio_priv(indio_dev);
+
+	return ((st->pwr_down_mode >> (chan->channel * 2)) & 0x3) - 1;
+}
+
+static int ad5686_set_powerdown_mode(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, unsigned int mode)
+{
+	struct ad5686_state *st = iio_priv(indio_dev);
+
+	st->pwr_down_mode &= ~(0x3 << (chan->channel * 2));
+	st->pwr_down_mode |= ((mode + 1) << (chan->channel * 2));
+
+	return 0;
+}
+
+static const struct iio_enum ad5686_powerdown_mode_enum = {
+	.items = ad5686_powerdown_modes,
+	.num_items = ARRAY_SIZE(ad5686_powerdown_modes),
+	.get = ad5686_get_powerdown_mode,
+	.set = ad5686_set_powerdown_mode,
+};
+
+static ssize_t ad5686_read_dac_powerdown(struct iio_dev *indio_dev,
+	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+	struct ad5686_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", !!(st->pwr_down_mask &
+			(0x3 << (chan->channel * 2))));
+}
+
+static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
+	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
+	 size_t len)
+{
+	bool readin;
+	int ret;
+	struct ad5686_state *st = iio_priv(indio_dev);
+
+	ret = strtobool(buf, &readin);
+	if (ret)
+		return ret;
+
+	if (readin)
+		st->pwr_down_mask |= (0x3 << (chan->channel * 2));
+	else
+		st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));
+
+	ret = ad5686_spi_write(st, AD5686_CMD_POWERDOWN_DAC, 0,
+			       st->pwr_down_mask & st->pwr_down_mode, 0);
+
+	return ret ? ret : len;
+}
+
+static int ad5686_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct ad5686_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&indio_dev->mlock);
+		ret = ad5686_spi_read(st, chan->address);
+		mutex_unlock(&indio_dev->mlock);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = st->vref_mv;
+		*val2 = chan->scan_type.realbits;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	}
+	return -EINVAL;
+}
+
+static int ad5686_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val,
+			       int val2,
+			       long mask)
+{
+	struct ad5686_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (val > (1 << chan->scan_type.realbits) || val < 0)
+			return -EINVAL;
+
+		mutex_lock(&indio_dev->mlock);
+		ret = ad5686_spi_write(st,
+				 AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
+				 chan->address,
+				 val,
+				 chan->scan_type.shift);
+		mutex_unlock(&indio_dev->mlock);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct iio_info ad5686_info = {
+	.read_raw = ad5686_read_raw,
+	.write_raw = ad5686_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static const struct iio_chan_spec_ext_info ad5686_ext_info[] = {
+	{
+		.name = "powerdown",
+		.read = ad5686_read_dac_powerdown,
+		.write = ad5686_write_dac_powerdown,
+		.shared = IIO_SEPARATE,
+	},
+	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5686_powerdown_mode_enum),
+	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5686_powerdown_mode_enum),
+	{ },
+};
+
+#define AD5868_CHANNEL(chan, bits, _shift) {			\
+		.type = IIO_VOLTAGE,				\
+		.indexed = 1,					\
+		.output = 1,					\
+		.channel = chan,				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
+		.address = AD5686_ADDR_DAC(chan),		\
+		.scan_type = {					\
+			.sign = 'u',				\
+			.realbits = (bits),			\
+			.storagebits = 16,			\
+			.shift = (_shift),			\
+		},						\
+		.ext_info = ad5686_ext_info,			\
+}
+
+static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
+	[ID_AD5684] = {
+		.channel[0] = AD5868_CHANNEL(0, 12, 4),
+		.channel[1] = AD5868_CHANNEL(1, 12, 4),
+		.channel[2] = AD5868_CHANNEL(2, 12, 4),
+		.channel[3] = AD5868_CHANNEL(3, 12, 4),
+		.int_vref_mv = 2500,
+	},
+	[ID_AD5685] = {
+		.channel[0] = AD5868_CHANNEL(0, 14, 2),
+		.channel[1] = AD5868_CHANNEL(1, 14, 2),
+		.channel[2] = AD5868_CHANNEL(2, 14, 2),
+		.channel[3] = AD5868_CHANNEL(3, 14, 2),
+		.int_vref_mv = 2500,
+	},
+	[ID_AD5686] = {
+		.channel[0] = AD5868_CHANNEL(0, 16, 0),
+		.channel[1] = AD5868_CHANNEL(1, 16, 0),
+		.channel[2] = AD5868_CHANNEL(2, 16, 0),
+		.channel[3] = AD5868_CHANNEL(3, 16, 0),
+		.int_vref_mv = 2500,
+	},
+};
+
+
+static int ad5686_probe(struct spi_device *spi)
+{
+	struct ad5686_state *st;
+	struct iio_dev *indio_dev;
+	int ret, voltage_uv = 0;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (indio_dev == NULL)
+		return  -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	spi_set_drvdata(spi, indio_dev);
+
+	st->reg = devm_regulator_get_optional(&spi->dev, "vcc");
+	if (!IS_ERR(st->reg)) {
+		ret = regulator_enable(st->reg);
+		if (ret)
+			return ret;
+
+		ret = regulator_get_voltage(st->reg);
+		if (ret < 0)
+			goto error_disable_reg;
+
+		voltage_uv = ret;
+	}
+
+	st->chip_info =
+		&ad5686_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+	if (voltage_uv)
+		st->vref_mv = voltage_uv / 1000;
+	else
+		st->vref_mv = st->chip_info->int_vref_mv;
+
+	st->spi = spi;
+
+	/* Set all the power down mode for all channels to 1K pulldown */
+	st->pwr_down_mode = 0x55;
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->info = &ad5686_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = st->chip_info->channel;
+	indio_dev->num_channels = AD5686_DAC_CHANNELS;
+
+	ret = ad5686_spi_write(st, AD5686_CMD_INTERNAL_REFER_SETUP, 0,
+				!!voltage_uv, 0);
+	if (ret)
+		goto error_disable_reg;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_disable_reg;
+
+	return 0;
+
+error_disable_reg:
+	if (!IS_ERR(st->reg))
+		regulator_disable(st->reg);
+	return ret;
+}
+
+static int ad5686_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad5686_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	if (!IS_ERR(st->reg))
+		regulator_disable(st->reg);
+
+	return 0;
+}
+
+static const struct spi_device_id ad5686_id[] = {
+	{"ad5684", ID_AD5684},
+	{"ad5685", ID_AD5685},
+	{"ad5686", ID_AD5686},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad5686_id);
+
+static struct spi_driver ad5686_driver = {
+	.driver = {
+		   .name = "ad5686",
+		   .owner = THIS_MODULE,
+		   },
+	.probe = ad5686_probe,
+	.remove = ad5686_remove,
+	.id_table = ad5686_id,
+};
+module_spi_driver(ad5686_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD5686/85/84 DAC");
+MODULE_LICENSE("GPL v2");