| /* |
| * AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302 |
| * |
| * Copyright 2010 Analog Devices Inc. |
| * |
| * Licensed under the GPL-2 or later. |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/sysfs.h> |
| #include <linux/spi/spi.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 { |
| struct spi_device *spi_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 = iio_priv(dev_info); |
| |
| 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 = iio_priv(dev_info); |
| 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 = iio_priv(dev_info); |
| 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(dev_info->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 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, |
| NULL, |
| }; |
| |
| static const struct attribute_group ad7314_attribute_group = { |
| .attrs = ad7314_attributes, |
| }; |
| |
| static const struct iio_info ad7314_info = { |
| .attrs = &ad7314_attribute_group, |
| .driver_module = THIS_MODULE, |
| }; |
| /* |
| * device probe and remove |
| */ |
| |
| static int __devinit ad7314_probe(struct spi_device *spi_dev) |
| { |
| struct ad7314_chip_info *chip; |
| struct iio_dev *indio_dev; |
| int ret = 0; |
| |
| indio_dev = iio_allocate_device(sizeof(*chip)); |
| if (indio_dev == NULL) { |
| ret = -ENOMEM; |
| goto error_ret; |
| } |
| chip = iio_priv(indio_dev); |
| /* this is only used for device removal purposes */ |
| dev_set_drvdata(&spi_dev->dev, chip); |
| |
| chip->spi_dev = spi_dev; |
| |
| indio_dev->name = spi_get_device_id(spi_dev)->name; |
| indio_dev->dev.parent = &spi_dev->dev; |
| indio_dev->info = &ad7314_info; |
| |
| ret = iio_device_register(indio_dev); |
| if (ret) |
| goto error_free_dev; |
| |
| dev_info(&spi_dev->dev, "%s temperature sensor registered.\n", |
| indio_dev->name); |
| |
| return 0; |
| error_free_dev: |
| iio_free_device(indio_dev); |
| error_ret: |
| return ret; |
| } |
| |
| static int __devexit ad7314_remove(struct spi_device *spi_dev) |
| { |
| struct iio_dev *indio_dev = dev_get_drvdata(&spi_dev->dev); |
| |
| dev_set_drvdata(&spi_dev->dev, NULL); |
| iio_device_unregister(indio_dev); |
| iio_free_device(indio_dev); |
| |
| 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); |