Initial import

1 files changed, 474 insertions, 0 deletions

diff --git a/drivers/iio/dac/ad5791.c b/drivers/iio/dac/ad5791.c
new file mode 100644
index 000000000..5ba785f18
--- /dev/null
+++ b/drivers/iio/dac/ad5791.c
@@ -0,0 +1,474 @@
+/*
+ * AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog
+ * Converter
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/device.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/module.h>
+#include <linux/bitops.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/dac/ad5791.h>
+
+#define AD5791_DAC_MASK			GENMASK(19, 0)
+
+#define AD5791_CMD_READ			BIT(23)
+#define AD5791_CMD_WRITE		0
+#define AD5791_ADDR(addr)		((addr) << 20)
+
+/* Registers */
+#define AD5791_ADDR_NOOP		0
+#define AD5791_ADDR_DAC0		1
+#define AD5791_ADDR_CTRL		2
+#define AD5791_ADDR_CLRCODE		3
+#define AD5791_ADDR_SW_CTRL		4
+
+/* Control Register */
+#define AD5791_CTRL_RBUF		BIT(1)
+#define AD5791_CTRL_OPGND		BIT(2)
+#define AD5791_CTRL_DACTRI		BIT(3)
+#define AD5791_CTRL_BIN2SC		BIT(4)
+#define AD5791_CTRL_SDODIS		BIT(5)
+#define AD5761_CTRL_LINCOMP(x)		((x) << 6)
+
+#define AD5791_LINCOMP_0_10		0
+#define AD5791_LINCOMP_10_12		1
+#define AD5791_LINCOMP_12_16		2
+#define AD5791_LINCOMP_16_19		3
+#define AD5791_LINCOMP_19_20		12
+
+#define AD5780_LINCOMP_0_10		0
+#define AD5780_LINCOMP_10_20		12
+
+/* Software Control Register */
+#define AD5791_SWCTRL_LDAC		BIT(0)
+#define AD5791_SWCTRL_CLR		BIT(1)
+#define AD5791_SWCTRL_RESET		BIT(2)
+
+#define AD5791_DAC_PWRDN_6K		0
+#define AD5791_DAC_PWRDN_3STATE		1
+
+/**
+ * struct ad5791_chip_info - chip specific information
+ * @get_lin_comp:	function pointer to the device specific function
+ */
+
+struct ad5791_chip_info {
+	int (*get_lin_comp)	(unsigned int span);
+};
+
+/**
+ * struct ad5791_state - driver instance specific data
+ * @spi:			spi_device
+ * @reg_vdd:		positive supply regulator
+ * @reg_vss:		negative supply regulator
+ * @chip_info:		chip model specific constants
+ * @vref_mv:		actual reference voltage used
+ * @vref_neg_mv:	voltage of the negative supply
+ * @pwr_down_mode	current power down mode
+ */
+
+struct ad5791_state {
+	struct spi_device		*spi;
+	struct regulator		*reg_vdd;
+	struct regulator		*reg_vss;
+	const struct ad5791_chip_info	*chip_info;
+	unsigned short			vref_mv;
+	unsigned int			vref_neg_mv;
+	unsigned			ctrl;
+	unsigned			pwr_down_mode;
+	bool				pwr_down;
+
+	union {
+		__be32 d32;
+		u8 d8[4];
+	} data[3] ____cacheline_aligned;
+};
+
+/**
+ * ad5791_supported_device_ids:
+ */
+
+enum ad5791_supported_device_ids {
+	ID_AD5760,
+	ID_AD5780,
+	ID_AD5781,
+	ID_AD5791,
+};
+
+static int ad5791_spi_write(struct ad5791_state *st, u8 addr, u32 val)
+{
+	st->data[0].d32 = cpu_to_be32(AD5791_CMD_WRITE |
+			      AD5791_ADDR(addr) |
+			      (val & AD5791_DAC_MASK));
+
+	return spi_write(st->spi, &st->data[0].d8[1], 3);
+}
+
+static int ad5791_spi_read(struct ad5791_state *st, u8 addr, u32 *val)
+{
+	int ret;
+	struct spi_transfer xfers[] = {
+		{
+			.tx_buf = &st->data[0].d8[1],
+			.bits_per_word = 8,
+			.len = 3,
+			.cs_change = 1,
+		}, {
+			.tx_buf = &st->data[1].d8[1],
+			.rx_buf = &st->data[2].d8[1],
+			.bits_per_word = 8,
+			.len = 3,
+		},
+	};
+
+	st->data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
+			      AD5791_ADDR(addr));
+	st->data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));
+
+	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
+
+	*val = be32_to_cpu(st->data[2].d32);
+
+	return ret;
+}
+
+static const char * const ad5791_powerdown_modes[] = {
+	"6kohm_to_gnd",
+	"three_state",
+};
+
+static int ad5791_get_powerdown_mode(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan)
+{
+	struct ad5791_state *st = iio_priv(indio_dev);
+
+	return st->pwr_down_mode;
+}
+
+static int ad5791_set_powerdown_mode(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, unsigned int mode)
+{
+	struct ad5791_state *st = iio_priv(indio_dev);
+
+	st->pwr_down_mode = mode;
+
+	return 0;
+}
+
+static const struct iio_enum ad5791_powerdown_mode_enum = {
+	.items = ad5791_powerdown_modes,
+	.num_items = ARRAY_SIZE(ad5791_powerdown_modes),
+	.get = ad5791_get_powerdown_mode,
+	.set = ad5791_set_powerdown_mode,
+};
+
+static ssize_t ad5791_read_dac_powerdown(struct iio_dev *indio_dev,
+	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+	struct ad5791_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", st->pwr_down);
+}
+
+static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev,
+	 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
+	 size_t len)
+{
+	bool pwr_down;
+	int ret;
+	struct ad5791_state *st = iio_priv(indio_dev);
+
+	ret = strtobool(buf, &pwr_down);
+	if (ret)
+		return ret;
+
+	if (!pwr_down) {
+		st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
+	} else {
+		if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K)
+			st->ctrl |= AD5791_CTRL_OPGND;
+		else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE)
+			st->ctrl |= AD5791_CTRL_DACTRI;
+	}
+	st->pwr_down = pwr_down;
+
+	ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl);
+
+	return ret ? ret : len;
+}
+
+static int ad5791_get_lin_comp(unsigned int span)
+{
+	if (span <= 10000)
+		return AD5791_LINCOMP_0_10;
+	else if (span <= 12000)
+		return AD5791_LINCOMP_10_12;
+	else if (span <= 16000)
+		return AD5791_LINCOMP_12_16;
+	else if (span <= 19000)
+		return AD5791_LINCOMP_16_19;
+	else
+		return AD5791_LINCOMP_19_20;
+}
+
+static int ad5780_get_lin_comp(unsigned int span)
+{
+	if (span <= 10000)
+		return AD5780_LINCOMP_0_10;
+	else
+		return AD5780_LINCOMP_10_20;
+}
+static const struct ad5791_chip_info ad5791_chip_info_tbl[] = {
+	[ID_AD5760] = {
+		.get_lin_comp = ad5780_get_lin_comp,
+	},
+	[ID_AD5780] = {
+		.get_lin_comp = ad5780_get_lin_comp,
+	},
+	[ID_AD5781] = {
+		.get_lin_comp = ad5791_get_lin_comp,
+	},
+	[ID_AD5791] = {
+		.get_lin_comp = ad5791_get_lin_comp,
+	},
+};
+
+static int ad5791_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct ad5791_state *st = iio_priv(indio_dev);
+	u64 val64;
+	int ret;
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		ret = ad5791_spi_read(st, chan->address, val);
+		if (ret)
+			return ret;
+		*val &= AD5791_DAC_MASK;
+		*val >>= chan->scan_type.shift;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = st->vref_mv;
+		*val2 = (1 << chan->scan_type.realbits) - 1;
+		return IIO_VAL_FRACTIONAL;
+	case IIO_CHAN_INFO_OFFSET:
+		val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits);
+		do_div(val64, st->vref_mv);
+		*val = -val64;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+
+};
+
+static const struct iio_chan_spec_ext_info ad5791_ext_info[] = {
+	{
+		.name = "powerdown",
+		.shared = IIO_SHARED_BY_TYPE,
+		.read = ad5791_read_dac_powerdown,
+		.write = ad5791_write_dac_powerdown,
+	},
+	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
+		 &ad5791_powerdown_mode_enum),
+	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5791_powerdown_mode_enum),
+	{ },
+};
+
+#define AD5791_CHAN(bits, _shift) {			\
+	.type = IIO_VOLTAGE,				\
+	.output = 1,					\
+	.indexed = 1,					\
+	.address = AD5791_ADDR_DAC0,			\
+	.channel = 0,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
+		BIT(IIO_CHAN_INFO_OFFSET),		\
+	.scan_type = {					\
+		.sign = 'u',				\
+		.realbits = (bits),			\
+		.storagebits = 24,			\
+		.shift = (_shift),			\
+	},						\
+	.ext_info = ad5791_ext_info,			\
+}
+
+static const struct iio_chan_spec ad5791_channels[] = {
+	[ID_AD5760] = AD5791_CHAN(16, 4),
+	[ID_AD5780] = AD5791_CHAN(18, 2),
+	[ID_AD5781] = AD5791_CHAN(18, 2),
+	[ID_AD5791] = AD5791_CHAN(20, 0)
+};
+
+static int ad5791_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val,
+			    int val2,
+			    long mask)
+{
+	struct ad5791_state *st = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		val &= GENMASK(chan->scan_type.realbits - 1, 0);
+		val <<= chan->scan_type.shift;
+
+		return ad5791_spi_write(st, chan->address, val);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info ad5791_info = {
+	.read_raw = &ad5791_read_raw,
+	.write_raw = &ad5791_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int ad5791_probe(struct spi_device *spi)
+{
+	struct ad5791_platform_data *pdata = spi->dev.platform_data;
+	struct iio_dev *indio_dev;
+	struct ad5791_state *st;
+	int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+	st = iio_priv(indio_dev);
+	st->reg_vdd = devm_regulator_get(&spi->dev, "vdd");
+	if (!IS_ERR(st->reg_vdd)) {
+		ret = regulator_enable(st->reg_vdd);
+		if (ret)
+			return ret;
+
+		ret = regulator_get_voltage(st->reg_vdd);
+		if (ret < 0)
+			goto error_disable_reg_pos;
+
+		pos_voltage_uv = ret;
+	}
+
+	st->reg_vss = devm_regulator_get(&spi->dev, "vss");
+	if (!IS_ERR(st->reg_vss)) {
+		ret = regulator_enable(st->reg_vss);
+		if (ret)
+			goto error_disable_reg_pos;
+
+		ret = regulator_get_voltage(st->reg_vss);
+		if (ret < 0)
+			goto error_disable_reg_neg;
+
+		neg_voltage_uv = ret;
+	}
+
+	st->pwr_down = true;
+	st->spi = spi;
+
+	if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
+		st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
+		st->vref_neg_mv = neg_voltage_uv / 1000;
+	} else if (pdata) {
+		st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv;
+		st->vref_neg_mv = pdata->vref_neg_mv;
+	} else {
+		dev_warn(&spi->dev, "reference voltage unspecified\n");
+	}
+
+	ret = ad5791_spi_write(st, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
+	if (ret)
+		goto error_disable_reg_neg;
+
+	st->chip_info =	&ad5791_chip_info_tbl[spi_get_device_id(spi)
+					      ->driver_data];
+
+
+	st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
+		  | ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
+		  AD5791_CTRL_BIN2SC;
+
+	ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl |
+		AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
+	if (ret)
+		goto error_disable_reg_neg;
+
+	spi_set_drvdata(spi, indio_dev);
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->info = &ad5791_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels
+		= &ad5791_channels[spi_get_device_id(spi)->driver_data];
+	indio_dev->num_channels = 1;
+	indio_dev->name = spi_get_device_id(st->spi)->name;
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_disable_reg_neg;
+
+	return 0;
+
+error_disable_reg_neg:
+	if (!IS_ERR(st->reg_vss))
+		regulator_disable(st->reg_vss);
+error_disable_reg_pos:
+	if (!IS_ERR(st->reg_vdd))
+		regulator_disable(st->reg_vdd);
+	return ret;
+}
+
+static int ad5791_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad5791_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	if (!IS_ERR(st->reg_vdd))
+		regulator_disable(st->reg_vdd);
+
+	if (!IS_ERR(st->reg_vss))
+		regulator_disable(st->reg_vss);
+
+	return 0;
+}
+
+static const struct spi_device_id ad5791_id[] = {
+	{"ad5760", ID_AD5760},
+	{"ad5780", ID_AD5780},
+	{"ad5781", ID_AD5781},
+	{"ad5790", ID_AD5791},
+	{"ad5791", ID_AD5791},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad5791_id);
+
+static struct spi_driver ad5791_driver = {
+	.driver = {
+		   .name = "ad5791",
+		   .owner = THIS_MODULE,
+		   },
+	.probe = ad5791_probe,
+	.remove = ad5791_remove,
+	.id_table = ad5791_id,
+};
+module_spi_driver(ad5791_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC");
+MODULE_LICENSE("GPL v2");