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staging: iio: adc: new driver for AD7298 devices 

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>
This commit is contained in:
Sonic Zhang 2010-10-27 21:43:56 -04:00 committed by Greg Kroah-Hartman
parent ddaecd5ba8
commit e8ada962bc
3 changed files with 509 additions and 0 deletions
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7
drivers/staging/iio/adc/Kconfig
View File

@ -48,6 +48,13 @@ config AD7291
Say yes here to build support for Analog Devices AD7291
temperature sensors.
config AD7298
tristate "Analog Devices AD7298 temperature sensor and ADC driver"
depends on SPI
help
Say yes here to build support for Analog Devices AD7298
temperature sensors and ADC.
config AD799X
tristate "Analog Devices AD799x ADC driver"
depends on I2C

1
drivers/staging/iio/adc/Makefile
View File

@ -18,3 +18,4 @@ obj-$(CONFIG_AD7476) += ad7476.o
obj-$(CONFIG_AD7150) += ad7150.o
obj-$(CONFIG_AD7152) += ad7152.o
obj-$(CONFIG_AD7291) += ad7291.o
obj-$(CONFIG_AD7298) += ad7298.o

501
drivers/staging/iio/adc/ad7298.c Normal file
View File

@ -0,0 +1,501 @@
/*
* AD7298 digital temperature sensor driver supporting AD7298
*
* 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"
/*
* AD7298 command
*/
#define AD7298_PD 0x1
#define AD7298_T_AVG_MASK 0x2
#define AD7298_EXT_REF 0x4
#define AD7298_T_SENSE_MASK 0x20
#define AD7298_VOLTAGE_MASK 0x3fc0
#define AD7298_VOLTAGE_OFFSET 0x6
#define AD7298_VOLTAGE_LIMIT_COUNT 8
#define AD7298_REPEAT 0x40
#define AD7298_WRITE 0x80
/*
* AD7298 value masks
*/
#define AD7298_CHANNEL_MASK 0xf000
#define AD7298_VALUE_MASK 0xfff
#define AD7298_T_VALUE_SIGN 0x400
#define AD7298_T_VALUE_FLOAT_OFFSET 2
#define AD7298_T_VALUE_FLOAT_MASK 0x2
/*
* struct ad7298_chip_info - chip specifc information
*/
struct ad7298_chip_info {
const char *name;
struct spi_device *spi_dev;
struct iio_dev *indio_dev;
u16 command;
u16 busy_pin;
u8 channels; /* Active voltage channels */
};
/*
* ad7298 register access by SPI
*/
static int ad7298_spi_write(struct ad7298_chip_info *chip, u16 data)
{
struct spi_device *spi_dev = chip->spi_dev;
int ret = 0;
data |= AD7298_WRITE;
data = cpu_to_be16(data);
ret = spi_write(spi_dev, (u8 *)&data, sizeof(data));
if (ret < 0)
dev_err(&spi_dev->dev, "SPI write error\n");
return ret;
}
static int ad7298_spi_read(struct ad7298_chip_info *chip, u16 mask, u16 *data)
{
struct spi_device *spi_dev = chip->spi_dev;
int ret = 0;
u8 count = chip->channels;
u16 command;
int i;
if (mask & AD7298_T_SENSE_MASK) {
command = chip->command & ~(AD7298_T_AVG_MASK | AD7298_VOLTAGE_MASK);
command |= AD7298_T_SENSE_MASK;
count = 1;
} else if (mask & AD7298_T_AVG_MASK) {
command = chip->command & ~AD7298_VOLTAGE_MASK;
command |= AD7298_T_SENSE_MASK | AD7298_T_AVG_MASK;
count = 2;
} else if (mask & AD7298_VOLTAGE_MASK) {
command = chip->command & ~(AD7298_T_AVG_MASK | AD7298_T_SENSE_MASK);
count = chip->channels;
}
ret = ad7298_spi_write(chip, chip->command);
if (ret < 0) {
dev_err(&spi_dev->dev, "SPI write command error\n");
return ret;
}
ret = spi_read(spi_dev, (u8 *)&command, sizeof(command));
if (ret < 0) {
dev_err(&spi_dev->dev, "SPI read error\n");
return ret;
}
i = 10000;
while (i && gpio_get_value(chip->busy_pin)) {
cpu_relax();
i--;
}
if (!i) {
dev_err(&spi_dev->dev, "Always in busy convertion.\n");
return -EBUSY;
}
for (i = 0; i < count; i++) {
ret = spi_read(spi_dev, (u8 *)&data[i], sizeof(data[i]));
if (ret < 0) {
dev_err(&spi_dev->dev, "SPI read error\n");
return ret;
}
*data = be16_to_cpu(data[i]);
}
return 0;
}
static ssize_t ad7298_show_mode(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
if (chip->command & AD7298_REPEAT)
return sprintf(buf, "repeat\n");
else
return sprintf(buf, "normal\n");
}
static ssize_t ad7298_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 ad7298_chip_info *chip = dev_info->dev_data;
if (strcmp(buf, "repeat"))
chip->command |= AD7298_REPEAT;
else
chip->command &= (~AD7298_REPEAT);
return 1;
}
static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,
ad7298_show_mode,
ad7298_store_mode,
0);
static ssize_t ad7298_show_available_modes(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "normal\nrepeat\n");
}
static IIO_DEVICE_ATTR(available_modes, S_IRUGO, ad7298_show_available_modes, NULL, 0);
static ssize_t ad7298_store_reset(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
u16 command;
int ret;
command = chip->command & ~AD7298_PD;
ret = ad7298_spi_write(chip, command);
if (ret)
return -EIO;
command = chip->command | AD7298_PD;
ret = ad7298_spi_write(chip, command);
if (ret)
return -EIO;
return len;
}
static IIO_DEVICE_ATTR(reset, S_IWUSR,
NULL,
ad7298_store_reset,
0);
static ssize_t ad7298_show_ext_ref(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
return sprintf(buf, "%d\n", !!(chip->command & AD7298_EXT_REF));
}
static ssize_t ad7298_store_ext_ref(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
u16 command;
int ret;
command = chip->command & (~AD7298_EXT_REF);
if (strcmp(buf, "1"))
command |= AD7298_EXT_REF;
ret = ad7298_spi_write(chip, command);
if (ret)
return -EIO;
chip->command = command;
return len;
}
static IIO_DEVICE_ATTR(ext_ref, S_IRUGO | S_IWUSR,
ad7298_show_ext_ref,
ad7298_store_ext_ref,
0);
static ssize_t ad7298_show_t_sense(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
u16 data;
char sign = ' ';
int ret;
ret = ad7298_spi_read(chip, AD7298_T_SENSE_MASK, &data);
if (ret)
return -EIO;
if (data & AD7298_T_VALUE_SIGN) {
/* convert supplement to positive value */
data = (AD7298_T_VALUE_SIGN << 1) - data;
sign = '-';
}
return sprintf(buf, "%c%d.%.2d\n", sign,
(data >> AD7298_T_VALUE_FLOAT_OFFSET),
(data & AD7298_T_VALUE_FLOAT_MASK) * 25);
}
static IIO_DEVICE_ATTR(t_sense, S_IRUGO, ad7298_show_t_sense, NULL, 0);
static ssize_t ad7298_show_t_average(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
u16 data[2];
char sign = ' ';
int ret;
ret = ad7298_spi_read(chip, AD7298_T_AVG_MASK, data);
if (ret)
return -EIO;
if (data[1] & AD7298_T_VALUE_SIGN) {
/* convert supplement to positive value */
data[1] = (AD7298_T_VALUE_SIGN << 1) - data[1];
sign = '-';
}
return sprintf(buf, "%c%d.%.2d\n", sign,
(data[1] >> AD7298_T_VALUE_FLOAT_OFFSET),
(data[1] & AD7298_T_VALUE_FLOAT_MASK) * 25);
}
static IIO_DEVICE_ATTR(t_average, S_IRUGO, ad7298_show_t_average, NULL, 0);
static ssize_t ad7298_show_voltage(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
u16 data[AD7298_VOLTAGE_LIMIT_COUNT];
int i, size, ret;
ret = ad7298_spi_read(chip, AD7298_VOLTAGE_MASK, data);
if (ret)
return -EIO;
for (i = 0; i < AD7298_VOLTAGE_LIMIT_COUNT; i++) {
if (chip->command & (AD7298_T_SENSE_MASK << i)) {
ret = sprintf(buf, "channel[%d]=%d\n", i,
data[i] & AD7298_VALUE_MASK);
if (ret < 0)
break;
buf += ret;
size += ret;
}
}
return size;
}
static IIO_DEVICE_ATTR(voltage, S_IRUGO, ad7298_show_voltage, NULL, 0);
static ssize_t ad7298_show_channel_mask(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
return sprintf(buf, "0x%x\n", (chip->command & AD7298_VOLTAGE_MASK) >>
AD7298_VOLTAGE_OFFSET);
}
static ssize_t ad7298_store_channel_mask(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
unsigned long data;
int i, ret;
ret = strict_strtoul(buf, 16, &data);
if (ret || data > 0xff)
return -EINVAL;
chip->command &= (~AD7298_VOLTAGE_MASK);
chip->command |= data << AD7298_VOLTAGE_OFFSET;
for (i = 0, chip->channels = 0; i < AD7298_VOLTAGE_LIMIT_COUNT; i++) {
if (chip->command & (AD7298_T_SENSE_MASK << i))
chip->channels++;
}
return ret;
}
static IIO_DEVICE_ATTR(channel_mask, S_IRUGO | S_IWUSR,
ad7298_show_channel_mask,
ad7298_store_channel_mask,
0);
static ssize_t ad7298_show_name(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *dev_info = dev_get_drvdata(dev);
struct ad7298_chip_info *chip = dev_info->dev_data;
return sprintf(buf, "%s\n", chip->name);
}
static IIO_DEVICE_ATTR(name, S_IRUGO, ad7298_show_name, NULL, 0);
static struct attribute *ad7298_attributes[] = {
&iio_dev_attr_available_modes.dev_attr.attr,
&iio_dev_attr_mode.dev_attr.attr,
&iio_dev_attr_reset.dev_attr.attr,
&iio_dev_attr_ext_ref.dev_attr.attr,
&iio_dev_attr_t_sense.dev_attr.attr,
&iio_dev_attr_t_average.dev_attr.attr,
&iio_dev_attr_voltage.dev_attr.attr,
&iio_dev_attr_channel_mask.dev_attr.attr,
&iio_dev_attr_name.dev_attr.attr,
NULL,
};
static const struct attribute_group ad7298_attribute_group = {
.attrs = ad7298_attributes,
};
/*
* device probe and remove
*/
static int __devinit ad7298_probe(struct spi_device *spi_dev)
{
struct ad7298_chip_info *chip;
unsigned short *pins = spi_dev->dev.platform_data;
int ret = 0;
chip = kzalloc(sizeof(struct ad7298_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->busy_pin = pins[0];
ret = gpio_request(chip->busy_pin, chip->name);
if (ret) {
dev_err(&spi_dev->dev, "Fail to request busy gpio PIN %d.\n",
chip->busy_pin);
goto error_free_chip;
}
gpio_direction_input(chip->busy_pin);
chip->indio_dev = iio_allocate_device();
if (chip->indio_dev == NULL) {
ret = -ENOMEM;
goto error_free_gpio;
}
chip->indio_dev->dev.parent = &spi_dev->dev;
chip->indio_dev->attrs = &ad7298_attribute_group;
chip->indio_dev->dev_data = (void *)chip;
chip->indio_dev->driver_module = THIS_MODULE;
chip->indio_dev->modes = INDIO_DIRECT_MODE;
ret = iio_device_register(chip->indio_dev);
if (ret)
goto error_free_dev;
dev_info(&spi_dev->dev, "%s temperature sensor and ADC registered.\n",
chip->name);
return 0;
error_free_dev:
iio_free_device(chip->indio_dev);
error_free_gpio:
gpio_free(chip->busy_pin);
error_free_chip:
kfree(chip);
return ret;
}
static int __devexit ad7298_remove(struct spi_device *spi_dev)
{
struct ad7298_chip_info *chip = dev_get_drvdata(&spi_dev->dev);
struct iio_dev *indio_dev = chip->indio_dev;
dev_set_drvdata(&spi_dev->dev, NULL);
iio_device_unregister(indio_dev);
iio_free_device(chip->indio_dev);
gpio_free(chip->busy_pin);
kfree(chip);
return 0;
}
static const struct spi_device_id ad7298_id[] = {
{ "ad7298", 0 },
{}
};
MODULE_DEVICE_TABLE(spi, ad7298_id);
static struct spi_driver ad7298_driver = {
.driver = {
.name = "ad7298",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = ad7298_probe,
.remove = __devexit_p(ad7298_remove),
.id_table = ad7298_id,
};
static __init int ad7298_init(void)
{
return spi_register_driver(&ad7298_driver);
}
static __exit void ad7298_exit(void)
{
spi_unregister_driver(&ad7298_driver);
}
MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7298 digital"
" temperature sensor and ADC driver");
MODULE_LICENSE("GPL v2");
module_init(ad7298_init);
module_exit(ad7298_exit);