| /* |
| * AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302 |
| * |
| * Copyright 2010 Analog Devices Inc. |
| * |
| * Licensed under the GPL-2 or later. |
| * |
| * Conversion to hwmon from IIO done by Jonathan Cameron <jic23@cam.ac.uk> |
| */ |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/sysfs.h> |
| #include <linux/spi/spi.h> |
| #include <linux/module.h> |
| #include <linux/err.h> |
| #include <linux/hwmon.h> |
| #include <linux/hwmon-sysfs.h> |
| |
| /* |
| * AD7314 temperature masks |
| */ |
| #define AD7314_TEMP_MASK 0x7FE0 |
| #define AD7314_TEMP_SHIFT 5 |
| |
| /* |
| * ADT7301 and ADT7302 temperature masks |
| */ |
| #define ADT7301_TEMP_MASK 0x3FFF |
| |
| enum ad7314_variant { |
| adt7301, |
| adt7302, |
| ad7314, |
| }; |
| |
| struct ad7314_data { |
| struct spi_device *spi_dev; |
| struct device *hwmon_dev; |
| u16 rx ____cacheline_aligned; |
| }; |
| |
| static int ad7314_spi_read(struct ad7314_data *chip) |
| { |
| int ret; |
| |
| ret = spi_read(chip->spi_dev, (u8 *)&chip->rx, sizeof(chip->rx)); |
| if (ret < 0) { |
| dev_err(&chip->spi_dev->dev, "SPI read error\n"); |
| return ret; |
| } |
| |
| return be16_to_cpu(chip->rx); |
| } |
| |
| static ssize_t ad7314_show_temperature(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct ad7314_data *chip = dev_get_drvdata(dev); |
| s16 data; |
| int ret; |
| |
| ret = ad7314_spi_read(chip); |
| if (ret < 0) |
| return ret; |
| switch (spi_get_device_id(chip->spi_dev)->driver_data) { |
| case ad7314: |
| data = (ret & AD7314_TEMP_MASK) >> AD7314_TEMP_SHIFT; |
| data = (data << 6) >> 6; |
| |
| return sprintf(buf, "%d\n", 250 * data); |
| case adt7301: |
| case adt7302: |
| /* |
| * Documented as a 13 bit twos complement register |
| * with a sign bit - which is a 14 bit 2's complement |
| * register. 1lsb - 31.25 milli degrees centigrade |
| */ |
| data = ret & ADT7301_TEMP_MASK; |
| data = (data << 2) >> 2; |
| |
| return sprintf(buf, "%d\n", |
| DIV_ROUND_CLOSEST(data * 3125, 100)); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static ssize_t ad7314_show_name(struct device *dev, |
| struct device_attribute *devattr, char *buf) |
| { |
| return sprintf(buf, "%s\n", to_spi_device(dev)->modalias); |
| } |
| |
| static DEVICE_ATTR(name, S_IRUGO, ad7314_show_name, NULL); |
| static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, |
| ad7314_show_temperature, NULL, 0); |
| |
| static struct attribute *ad7314_attributes[] = { |
| &dev_attr_name.attr, |
| &sensor_dev_attr_temp1_input.dev_attr.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group ad7314_group = { |
| .attrs = ad7314_attributes, |
| }; |
| |
| static int __devinit ad7314_probe(struct spi_device *spi_dev) |
| { |
| int ret; |
| struct ad7314_data *chip; |
| |
| chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL); |
| if (chip == NULL) |
| return -ENOMEM; |
| |
| dev_set_drvdata(&spi_dev->dev, chip); |
| |
| ret = sysfs_create_group(&spi_dev->dev.kobj, &ad7314_group); |
| if (ret < 0) |
| return ret; |
| |
| chip->hwmon_dev = hwmon_device_register(&spi_dev->dev); |
| if (IS_ERR(chip->hwmon_dev)) { |
| ret = PTR_ERR(chip->hwmon_dev); |
| goto error_remove_group; |
| } |
| chip->spi_dev = spi_dev; |
| |
| return 0; |
| error_remove_group: |
| sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group); |
| return ret; |
| } |
| |
| static int __devexit ad7314_remove(struct spi_device *spi_dev) |
| { |
| struct ad7314_data *chip = dev_get_drvdata(&spi_dev->dev); |
| |
| hwmon_device_unregister(chip->hwmon_dev); |
| sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group); |
| |
| return 0; |
| } |
| |
| static const struct spi_device_id ad7314_id[] = { |
| { "adt7301", adt7301 }, |
| { "adt7302", adt7302 }, |
| { "ad7314", ad7314 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(spi, ad7314_id); |
| |
| static struct spi_driver ad7314_driver = { |
| .driver = { |
| .name = "ad7314", |
| .owner = THIS_MODULE, |
| }, |
| .probe = ad7314_probe, |
| .remove = ad7314_remove, |
| .id_table = ad7314_id, |
| }; |
| |
| module_spi_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"); |