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staging: iio: adc: new driver for AD7314 devices
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Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Sonic Zhang authored and Greg Kroah-Hartman committed Nov 9, 2010
1 parent e8ada96 commit f84c26e
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7 changes: 7 additions & 0 deletions drivers/staging/iio/adc/Kconfig
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Expand Up @@ -55,6 +55,13 @@ config AD7298
Say yes here to build support for Analog Devices AD7298
temperature sensors and ADC.

config AD7314
tristate "Analog Devices AD7314 temperature sensor driver"
depends on SPI
help
Say yes here to build support for Analog Devices AD7314
temperature sensors.

config AD799X
tristate "Analog Devices AD799x ADC driver"
depends on I2C
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1 change: 1 addition & 0 deletions drivers/staging/iio/adc/Makefile
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Expand Up @@ -19,3 +19,4 @@ obj-$(CONFIG_AD7150) += ad7150.o
obj-$(CONFIG_AD7152) += ad7152.o
obj-$(CONFIG_AD7291) += ad7291.o
obj-$(CONFIG_AD7298) += ad7298.o
obj-$(CONFIG_AD7314) += ad7314.o
308 changes: 308 additions & 0 deletions drivers/staging/iio/adc/ad7314.c
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@@ -0,0 +1,308 @@
/*
* AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302
*
* Copyright 2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/

#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/workqueue.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/list.h>
#include <linux/spi/spi.h>
#include <linux/rtc.h>

#include "../iio.h"
#include "../sysfs.h"

/*
* AD7314 power mode
*/
#define AD7314_PD 0x2000

/*
* AD7314 temperature masks
*/
#define AD7314_TEMP_SIGN 0x200
#define AD7314_TEMP_MASK 0x7FE0
#define AD7314_TEMP_OFFSET 5
#define AD7314_TEMP_FLOAT_OFFSET 2
#define AD7314_TEMP_FLOAT_MASK 0x3

/*
* ADT7301 and ADT7302 temperature masks
*/
#define ADT7301_TEMP_SIGN 0x2000
#define ADT7301_TEMP_MASK 0x2FFF
#define ADT7301_TEMP_FLOAT_OFFSET 5
#define ADT7301_TEMP_FLOAT_MASK 0x1F

/*
* struct ad7314_chip_info - chip specifc information
*/

struct ad7314_chip_info {
const char *name;
struct spi_device *spi_dev;
struct iio_dev *indio_dev;
s64 last_timestamp;
u8 mode;
};

/*
* ad7314 register access by SPI
*/

static int ad7314_spi_read(struct ad7314_chip_info *chip, u16 *data)
{
struct spi_device *spi_dev = chip->spi_dev;
int ret = 0;
u16 value;

ret = spi_read(spi_dev, (u8 *)&value, sizeof(value));
if (ret < 0) {
dev_err(&spi_dev->dev, "SPI read error\n");
return ret;
}

*data = be16_to_cpu((u16)value);

return ret;
}

static int ad7314_spi_write(struct ad7314_chip_info *chip, u16 data)
{
struct spi_device *spi_dev = chip->spi_dev;
int ret = 0;
u16 value = cpu_to_be16(data);

ret = spi_write(spi_dev, (u8 *)&value, sizeof(value));
if (ret < 0)
dev_err(&spi_dev->dev, "SPI write error\n");

return ret;
}

static ssize_t ad7314_show_mode(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7314_chip_info *chip = dev_info->dev_data;

if (chip->mode)
return sprintf(buf, "power-save\n");
else
return sprintf(buf, "full\n");
}

static ssize_t ad7314_store_mode(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7314_chip_info *chip = dev_info->dev_data;
u16 mode = 0;
int ret;

if (!strcmp(buf, "full"))
mode = AD7314_PD;

ret = ad7314_spi_write(chip, mode);
if (ret)
return -EIO;

chip->mode = mode;

return len;
}

static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,
ad7314_show_mode,
ad7314_store_mode,
0);

static ssize_t ad7314_show_available_modes(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "full\npower-save\n");
}

static IIO_DEVICE_ATTR(available_modes, S_IRUGO, ad7314_show_available_modes, NULL, 0);

static ssize_t ad7314_show_temperature(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7314_chip_info *chip = dev_info->dev_data;
u16 data;
char sign = ' ';
int ret;

if (chip->mode) {
ret = ad7314_spi_write(chip, 0);
if (ret)
return -EIO;
}

ret = ad7314_spi_read(chip, &data);
if (ret)
return -EIO;

if (chip->mode)
ad7314_spi_write(chip, chip->mode);

if (strcmp(chip->name, "ad7314")) {
data = (data & AD7314_TEMP_MASK) >>
AD7314_TEMP_OFFSET;
if (data & AD7314_TEMP_SIGN) {
data = (AD7314_TEMP_SIGN << 1) - data;
sign = '-';
}

return sprintf(buf, "%c%d.%.2d\n", sign,
data >> AD7314_TEMP_FLOAT_OFFSET,
(data & AD7314_TEMP_FLOAT_MASK) * 25);
} else {
data &= ADT7301_TEMP_MASK;
if (data & ADT7301_TEMP_SIGN) {
data = (ADT7301_TEMP_SIGN << 1) - data;
sign = '-';
}

return sprintf(buf, "%c%d.%.5d\n", sign,
data >> ADT7301_TEMP_FLOAT_OFFSET,
(data & ADT7301_TEMP_FLOAT_MASK) * 3125);
}
}

static IIO_DEVICE_ATTR(temperature, S_IRUGO, ad7314_show_temperature, NULL, 0);

static ssize_t ad7314_show_name(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7314_chip_info *chip = dev_info->dev_data;
return sprintf(buf, "%s\n", chip->name);
}

static IIO_DEVICE_ATTR(name, S_IRUGO, ad7314_show_name, NULL, 0);

static struct attribute *ad7314_attributes[] = {
&iio_dev_attr_available_modes.dev_attr.attr,
&iio_dev_attr_mode.dev_attr.attr,
&iio_dev_attr_temperature.dev_attr.attr,
&iio_dev_attr_name.dev_attr.attr,
NULL,
};

static const struct attribute_group ad7314_attribute_group = {
.attrs = ad7314_attributes,
};

/*
* device probe and remove
*/

static int __devinit ad7314_probe(struct spi_device *spi_dev)
{
struct ad7314_chip_info *chip;
int ret = 0;

chip = kzalloc(sizeof(struct ad7314_chip_info), GFP_KERNEL);

if (chip == NULL)
return -ENOMEM;

/* this is only used for device removal purposes */
dev_set_drvdata(&spi_dev->dev, chip);

chip->spi_dev = spi_dev;
chip->name = spi_dev->modalias;

chip->indio_dev = iio_allocate_device();
if (chip->indio_dev == NULL) {
ret = -ENOMEM;
goto error_free_chip;
}

chip->indio_dev->dev.parent = &spi_dev->dev;
chip->indio_dev->attrs = &ad7314_attribute_group;
chip->indio_dev->dev_data = (void *)chip;
chip->indio_dev->driver_module = THIS_MODULE;

ret = iio_device_register(chip->indio_dev);
if (ret)
goto error_free_dev;

dev_info(&spi_dev->dev, "%s temperature sensor registered.\n",
chip->name);

return 0;
error_free_dev:
iio_free_device(chip->indio_dev);
error_free_chip:
kfree(chip);

return ret;
}

static int __devexit ad7314_remove(struct spi_device *spi_dev)
{
struct ad7314_chip_info *chip = dev_get_drvdata(&spi_dev->dev);
struct iio_dev *indio_dev = chip->indio_dev;

dev_set_drvdata(&spi_dev->dev, NULL);
if (spi_dev->irq)
iio_unregister_interrupt_line(indio_dev, 0);
iio_device_unregister(indio_dev);
iio_free_device(chip->indio_dev);
kfree(chip);

return 0;
}

static const struct spi_device_id ad7314_id[] = {
{ "adt7301", 0 },
{ "adt7302", 0 },
{ "ad7314", 0 },
{}
};

static struct spi_driver ad7314_driver = {
.driver = {
.name = "ad7314",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = ad7314_probe,
.remove = __devexit_p(ad7314_remove),
.id_table = ad7314_id,
};

static __init int ad7314_init(void)
{
return spi_register_driver(&ad7314_driver);
}

static __exit void ad7314_exit(void)
{
spi_unregister_driver(&ad7314_driver);
}

MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital"
" temperature sensor driver");
MODULE_LICENSE("GPL v2");

module_init(ad7314_init);
module_exit(ad7314_exit);

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