283 lines
5.8 KiB
C
283 lines
5.8 KiB
C
/*
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* AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302
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*
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* Copyright 2010 Analog Devices Inc.
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include <linux/spi/spi.h>
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#include <linux/module.h>
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#include "../iio.h"
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#include "../sysfs.h"
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/*
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* AD7314 power mode
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*/
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#define AD7314_PD 0x2000
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/*
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* AD7314 temperature masks
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*/
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#define AD7314_TEMP_SIGN 0x200
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#define AD7314_TEMP_MASK 0x7FE0
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#define AD7314_TEMP_OFFSET 5
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#define AD7314_TEMP_FLOAT_OFFSET 2
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#define AD7314_TEMP_FLOAT_MASK 0x3
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/*
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* ADT7301 and ADT7302 temperature masks
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*/
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#define ADT7301_TEMP_SIGN 0x2000
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#define ADT7301_TEMP_MASK 0x2FFF
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#define ADT7301_TEMP_FLOAT_OFFSET 5
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#define ADT7301_TEMP_FLOAT_MASK 0x1F
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/*
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* struct ad7314_chip_info - chip specifc information
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*/
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struct ad7314_chip_info {
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struct spi_device *spi_dev;
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s64 last_timestamp;
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u8 mode;
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};
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/*
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* ad7314 register access by SPI
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*/
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static int ad7314_spi_read(struct ad7314_chip_info *chip, u16 *data)
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{
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struct spi_device *spi_dev = chip->spi_dev;
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int ret = 0;
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u16 value;
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ret = spi_read(spi_dev, (u8 *)&value, sizeof(value));
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if (ret < 0) {
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dev_err(&spi_dev->dev, "SPI read error\n");
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return ret;
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}
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*data = be16_to_cpu((u16)value);
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return ret;
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}
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static int ad7314_spi_write(struct ad7314_chip_info *chip, u16 data)
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{
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struct spi_device *spi_dev = chip->spi_dev;
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int ret = 0;
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u16 value = cpu_to_be16(data);
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ret = spi_write(spi_dev, (u8 *)&value, sizeof(value));
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if (ret < 0)
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dev_err(&spi_dev->dev, "SPI write error\n");
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return ret;
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}
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static ssize_t ad7314_show_mode(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_dev *dev_info = dev_get_drvdata(dev);
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struct ad7314_chip_info *chip = iio_priv(dev_info);
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if (chip->mode)
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return sprintf(buf, "power-save\n");
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else
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return sprintf(buf, "full\n");
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}
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static ssize_t ad7314_store_mode(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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struct iio_dev *dev_info = dev_get_drvdata(dev);
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struct ad7314_chip_info *chip = iio_priv(dev_info);
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u16 mode = 0;
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int ret;
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if (!strcmp(buf, "full"))
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mode = AD7314_PD;
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ret = ad7314_spi_write(chip, mode);
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if (ret)
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return -EIO;
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chip->mode = mode;
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return len;
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}
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static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,
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ad7314_show_mode,
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ad7314_store_mode,
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0);
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static ssize_t ad7314_show_available_modes(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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return sprintf(buf, "full\npower-save\n");
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}
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static IIO_DEVICE_ATTR(available_modes, S_IRUGO, ad7314_show_available_modes, NULL, 0);
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static ssize_t ad7314_show_temperature(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_dev *dev_info = dev_get_drvdata(dev);
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struct ad7314_chip_info *chip = iio_priv(dev_info);
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u16 data;
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char sign = ' ';
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int ret;
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if (chip->mode) {
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ret = ad7314_spi_write(chip, 0);
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if (ret)
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return -EIO;
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}
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ret = ad7314_spi_read(chip, &data);
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if (ret)
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return -EIO;
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if (chip->mode)
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ad7314_spi_write(chip, chip->mode);
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if (strcmp(dev_info->name, "ad7314")) {
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data = (data & AD7314_TEMP_MASK) >>
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AD7314_TEMP_OFFSET;
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if (data & AD7314_TEMP_SIGN) {
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data = (AD7314_TEMP_SIGN << 1) - data;
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sign = '-';
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}
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return sprintf(buf, "%c%d.%.2d\n", sign,
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data >> AD7314_TEMP_FLOAT_OFFSET,
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(data & AD7314_TEMP_FLOAT_MASK) * 25);
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} else {
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data &= ADT7301_TEMP_MASK;
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if (data & ADT7301_TEMP_SIGN) {
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data = (ADT7301_TEMP_SIGN << 1) - data;
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sign = '-';
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}
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return sprintf(buf, "%c%d.%.5d\n", sign,
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data >> ADT7301_TEMP_FLOAT_OFFSET,
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(data & ADT7301_TEMP_FLOAT_MASK) * 3125);
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}
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}
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static IIO_DEVICE_ATTR(temperature, S_IRUGO, ad7314_show_temperature, NULL, 0);
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static struct attribute *ad7314_attributes[] = {
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&iio_dev_attr_available_modes.dev_attr.attr,
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&iio_dev_attr_mode.dev_attr.attr,
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&iio_dev_attr_temperature.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group ad7314_attribute_group = {
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.attrs = ad7314_attributes,
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};
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static const struct iio_info ad7314_info = {
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.attrs = &ad7314_attribute_group,
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.driver_module = THIS_MODULE,
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};
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/*
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* device probe and remove
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*/
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static int __devinit ad7314_probe(struct spi_device *spi_dev)
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{
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struct ad7314_chip_info *chip;
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struct iio_dev *indio_dev;
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int ret = 0;
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indio_dev = iio_allocate_device(sizeof(*chip));
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if (indio_dev == NULL) {
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ret = -ENOMEM;
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goto error_ret;
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}
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chip = iio_priv(indio_dev);
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/* this is only used for device removal purposes */
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dev_set_drvdata(&spi_dev->dev, chip);
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chip->spi_dev = spi_dev;
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indio_dev->name = spi_get_device_id(spi_dev)->name;
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indio_dev->dev.parent = &spi_dev->dev;
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indio_dev->info = &ad7314_info;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_free_dev;
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dev_info(&spi_dev->dev, "%s temperature sensor registered.\n",
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indio_dev->name);
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return 0;
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error_free_dev:
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iio_free_device(indio_dev);
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error_ret:
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return ret;
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}
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static int __devexit ad7314_remove(struct spi_device *spi_dev)
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{
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struct iio_dev *indio_dev = dev_get_drvdata(&spi_dev->dev);
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dev_set_drvdata(&spi_dev->dev, NULL);
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iio_device_unregister(indio_dev);
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iio_free_device(indio_dev);
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return 0;
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}
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static const struct spi_device_id ad7314_id[] = {
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{ "adt7301", 0 },
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{ "adt7302", 0 },
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{ "ad7314", 0 },
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{}
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};
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static struct spi_driver ad7314_driver = {
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.driver = {
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.name = "ad7314",
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.bus = &spi_bus_type,
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.owner = THIS_MODULE,
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},
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.probe = ad7314_probe,
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.remove = __devexit_p(ad7314_remove),
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.id_table = ad7314_id,
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};
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static __init int ad7314_init(void)
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{
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return spi_register_driver(&ad7314_driver);
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}
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static __exit void ad7314_exit(void)
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{
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spi_unregister_driver(&ad7314_driver);
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}
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MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
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MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital"
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" temperature sensor driver");
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MODULE_LICENSE("GPL v2");
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module_init(ad7314_init);
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module_exit(ad7314_exit);
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