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Commit c2f37c8d authored by Michael Hennerich's avatar Michael Hennerich Committed by Greg Kroah-Hartman
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iio: dac: New driver for AD5686R, AD5685R, AD5684R Digital to analog converters 



New driver for AD5686R, AD5685R, AD5684R Quad channel digital to analog converters

Changes since V1:

drop header file
use strtobool()
Fix dev attribute macros
Reorder probe() function

Signed-off-by: default avatarMichael Hennerich <michael.hennerich@analog.com>
Acked-by: default avatarJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent ae19178e

drivers/staging/iio/dac/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -42,6 +42,17 @@ config AD5791 
	  To compile this driver as a module, choose M here: the

	  module will be called ad5791.



config AD5686

	tristate "Analog Devices AD5686R/AD5685R/AD5684R DAC SPI driver"

	depends on SPI

	help

	  Say yes here to build support for Analog Devices AD5686R, AD5685R,

	  AD5684R, AD5791 Voltage Output Digital to

	  Analog Converter.



	  To compile this driver as a module, choose M here: the

	  module will be called ad5686.



config MAX517

	tristate "Maxim MAX517/518/519 DAC driver"

	depends on I2C && EXPERIMENTAL

drivers/staging/iio/dac/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -6,4 +6,5 @@ obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o 
obj-$(CONFIG_AD5504) += ad5504.o

obj-$(CONFIG_AD5446) += ad5446.o

obj-$(CONFIG_AD5791) += ad5791.o

obj-$(CONFIG_AD5686) += ad5686.o

obj-$(CONFIG_MAX517) += max517.o

drivers/staging/iio/dac/ad5686.c

0 → 100644
+497 −0
Original line number Diff line number Diff line 
/*

 * AD5686R, AD5685R, AD5684R Digital to analog converters  driver

 *

 * Copyright 2011 Analog Devices Inc.

 *

 * Licensed under the GPL-2.

 */



#include <linux/interrupt.h>

#include <linux/gpio.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 "../iio.h"

#include "../sysfs.h"

#include "dac.h"



#define AD5686_DAC_CHANNELS			4



#define AD5686_ADDR(x)				((x) << 16)

#define AD5686_CMD(x)				((x) << 20)



#define AD5686_ADDR_DAC0			0x1

#define AD5686_ADDR_DAC1			0x2

#define AD5686_ADDR_DAC2			0x4

#define AD5686_ADDR_DAC3			0x8

#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 {

		u32 d32;

		u8 d8[4];

	} data[3] ____cacheline_aligned;

};



/**

 * ad5686_supported_device_ids:

 */



enum ad5686_supported_device_ids {

	ID_AD5684,

	ID_AD5685,

	ID_AD5686,

};



static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {

	[ID_AD5684] = {

		.channel[0] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 0, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC0,

				    0, IIO_ST('u', 12, 16, 4), 0),

		.channel[1] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 1, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC1,

				    1, IIO_ST('u', 12, 16, 4), 0),

		.channel[2] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 2, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC2,

				    2, IIO_ST('u', 12, 16, 4), 0),

		.channel[3] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 3, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC3,

				    3, IIO_ST('u', 12, 16, 4), 0),

		.int_vref_mv = 2500,

	},

	[ID_AD5685] = {

		.channel[0] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 0, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC0,

				    0, IIO_ST('u', 14, 16, 2), 0),

		.channel[1] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 1, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC1,

				    1, IIO_ST('u', 14, 16, 2), 0),

		.channel[2] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 2, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC2,

				    2, IIO_ST('u', 14, 16, 2), 0),

		.channel[3] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 3, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC3,

				    3, IIO_ST('u', 14, 16, 2), 0),

		.int_vref_mv = 2500,

	},

	[ID_AD5686] = {

		.channel[0] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 0, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC0,

				    0, IIO_ST('u', 16, 16, 0), 0),

		.channel[1] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 1, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC1,

				    1, IIO_ST('u', 16, 16, 0), 0),

		.channel[2] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 2, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC2,

				    2, IIO_ST('u', 16, 16, 0), 0),

		.channel[3] = IIO_CHAN(IIO_OUT, 0, 1, 0, NULL, 3, 0,

				    (1 << IIO_CHAN_INFO_SCALE_SHARED),

				    AD5686_ADDR_DAC3,

				    3, IIO_ST('u', 16, 16, 0), 0),

		.int_vref_mv = 2500,

	},

};



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,

		},

	};

	struct spi_message m;

	int ret;



	spi_message_init(&m);

	spi_message_add_tail(&t[0], &m);

	spi_message_add_tail(&t[1], &m);



	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(st->spi, &m);

	if (ret < 0)

		return ret;



	return be32_to_cpu(st->data[2].d32);

}



static ssize_t ad5686_read_powerdown_mode(struct device *dev,

				      struct device_attribute *attr, char *buf)

{

	struct iio_dev *indio_dev = dev_get_drvdata(dev);

	struct ad5686_state *st = iio_priv(indio_dev);

	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);



	char mode[][15] = {"", "1kohm_to_gnd", "100kohm_to_gnd", "three_state"};



	return sprintf(buf, "%s\n", mode[(st->pwr_down_mode >>

					 (this_attr->address * 2)) & 0x3]);

}



static ssize_t ad5686_write_powerdown_mode(struct device *dev,

				       struct device_attribute *attr,

				       const char *buf, size_t len)

{

	struct iio_dev *indio_dev = dev_get_drvdata(dev);

	struct ad5686_state *st = iio_priv(indio_dev);

	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);

	unsigned mode;



	if (sysfs_streq(buf, "1kohm_to_gnd"))

		mode = AD5686_LDAC_PWRDN_1K;

	else if (sysfs_streq(buf, "100kohm_to_gnd"))

		mode = AD5686_LDAC_PWRDN_100K;

	else if (sysfs_streq(buf, "three_state"))

		mode = AD5686_LDAC_PWRDN_3STATE;

	else

		return  -EINVAL;



	st->pwr_down_mode &= ~(0x3 << (this_attr->address * 2));

	st->pwr_down_mode |= (mode << (this_attr->address * 2));



	return len;

}



static ssize_t ad5686_read_dac_powerdown(struct device *dev,

					   struct device_attribute *attr,

					   char *buf)

{

	struct iio_dev *indio_dev = dev_get_drvdata(dev);

	struct ad5686_state *st = iio_priv(indio_dev);

	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);



	return sprintf(buf, "%d\n", !!(st->pwr_down_mask &

			(0x3 << (this_attr->address * 2))));

}



static ssize_t ad5686_write_dac_powerdown(struct device *dev,

					    struct device_attribute *attr,

					    const char *buf, size_t len)

{

	bool readin;

	int ret;

	struct iio_dev *indio_dev = dev_get_drvdata(dev);

	struct ad5686_state *st = iio_priv(indio_dev);

	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);



	ret = strtobool(buf, &readin);

	if (ret)

		return ret;



	if (readin == true)

		st->pwr_down_mask |= (0x3 << (this_attr->address * 2));

	else

		st->pwr_down_mask &= ~(0x3 << (this_attr->address * 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 IIO_CONST_ATTR(out_powerdown_mode_available,

			"1kohm_to_gnd 100kohm_to_gnd three_state");



#define IIO_DEV_ATTR_DAC_POWERDOWN_MODE(_num) \

	IIO_DEVICE_ATTR(out##_num##_powerdown_mode, S_IRUGO | S_IWUSR,	\

			ad5686_read_powerdown_mode,			\

			ad5686_write_powerdown_mode, _num)



static IIO_DEV_ATTR_DAC_POWERDOWN_MODE(0);

static IIO_DEV_ATTR_DAC_POWERDOWN_MODE(1);

static IIO_DEV_ATTR_DAC_POWERDOWN_MODE(2);

static IIO_DEV_ATTR_DAC_POWERDOWN_MODE(3);



#define IIO_DEV_ATTR_DAC_POWERDOWN(_num)	\

	IIO_DEVICE_ATTR(out##_num##_powerdown, S_IRUGO | S_IWUSR,	\

			ad5686_read_dac_powerdown,			\

			ad5686_write_dac_powerdown, _num)



static IIO_DEV_ATTR_DAC_POWERDOWN(0);

static IIO_DEV_ATTR_DAC_POWERDOWN(1);

static IIO_DEV_ATTR_DAC_POWERDOWN(2);

static IIO_DEV_ATTR_DAC_POWERDOWN(3);



static struct attribute *ad5686_attributes[] = {

	&iio_dev_attr_out0_powerdown.dev_attr.attr,

	&iio_dev_attr_out1_powerdown.dev_attr.attr,

	&iio_dev_attr_out2_powerdown.dev_attr.attr,

	&iio_dev_attr_out3_powerdown.dev_attr.attr,

	&iio_dev_attr_out0_powerdown_mode.dev_attr.attr,

	&iio_dev_attr_out1_powerdown_mode.dev_attr.attr,

	&iio_dev_attr_out2_powerdown_mode.dev_attr.attr,

	&iio_dev_attr_out3_powerdown_mode.dev_attr.attr,

	&iio_const_attr_out_powerdown_mode_available.dev_attr.attr,

	NULL,

};



static const struct attribute_group ad5686_attribute_group = {

	.attrs = ad5686_attributes,

};



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);

	unsigned long scale_uv;

	int ret;



	switch (m) {

	case 0:

		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;

		break;

	case (1 << IIO_CHAN_INFO_SCALE_SHARED):

		scale_uv = (st->vref_mv * 100000)

			>> (chan->scan_type.realbits);

		*val =  scale_uv / 100000;

		*val2 = (scale_uv % 100000) * 10;

		return IIO_VAL_INT_PLUS_MICRO;



	}

	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 0:

		if (val > (1 << chan->scan_type.realbits))

			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,

	.attrs = &ad5686_attribute_group,

	.driver_module = THIS_MODULE,

};



static int __devinit ad5686_probe(struct spi_device *spi)

{

	struct ad5686_state *st;

	struct iio_dev *indio_dev;

	int ret, regdone = 0, voltage_uv = 0;



	indio_dev = iio_allocate_device(sizeof(*st));

	if (indio_dev == NULL)

		return  -ENOMEM;



	st = iio_priv(indio_dev);

	spi_set_drvdata(spi, indio_dev);



	st->reg = regulator_get(&spi->dev, "vcc");

	if (!IS_ERR(st->reg)) {

		ret = regulator_enable(st->reg);

		if (ret)

			goto error_put_reg;



		voltage_uv = regulator_get_voltage(st->reg);

	}



	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;



	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 = iio_device_register(indio_dev);

	if (ret)

		goto error_disable_reg;



	regdone = 1;

	ret = ad5686_spi_write(st, AD5686_CMD_INTERNAL_REFER_SETUP, 0,

				!!voltage_uv, 0);

	if (ret)

		goto error_disable_reg;



	return 0;



error_disable_reg:

	if (!IS_ERR(st->reg))

		regulator_disable(st->reg);

error_put_reg:

	if (!IS_ERR(st->reg))

		regulator_put(st->reg);



	if (regdone)

		iio_device_unregister(indio_dev);

	else

		iio_free_device(indio_dev);



	return ret;

}



static int __devexit ad5686_remove(struct spi_device *spi)

{

	struct iio_dev *indio_dev = spi_get_drvdata(spi);

	struct ad5686_state *st = iio_priv(indio_dev);

	struct regulator *reg = st->reg;



	if (!IS_ERR(reg)) {

		regulator_disable(reg);

		regulator_put(reg);

	}



	iio_device_unregister(indio_dev);



	return 0;

}



static const struct spi_device_id ad5686_id[] = {

	{"ad5684", ID_AD5684},

	{"ad5685", ID_AD5685},

	{"ad5686", ID_AD5686},

	{}

};



static struct spi_driver ad5686_driver = {

	.driver = {

		   .name = "ad5686",

		   .owner = THIS_MODULE,

		   },

	.probe = ad5686_probe,

	.remove = __devexit_p(ad5686_remove),

	.id_table = ad5686_id,

};



static __init int ad5686_spi_init(void)

{

	return spi_register_driver(&ad5686_driver);

}

module_init(ad5686_spi_init);



static __exit void ad5686_spi_exit(void)

{

	spi_unregister_driver(&ad5686_driver);

}

module_exit(ad5686_spi_exit);



MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");

MODULE_DESCRIPTION("Analog Devices AD5686/85/84 DAC");

MODULE_LICENSE("GPL v2");