/* * 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 power mode */ #define AD7314_PD 0x2000 /* * AD7314 temperature masks */ #define AD7314_TEMP_SIGN 0x200 #define AD7314_TEMP_MASK 0x7FE0 #define AD7314_TEMP_OFFSET 5 /* * ADT7301 and ADT7302 temperature masks */ #define ADT7301_TEMP_SIGN 0x2000 #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, s16 *data) { 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; } *data = be16_to_cpu(chip->rx); return ret; } 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, &data); if (ret < 0) return ret; switch (spi_get_device_id(chip->spi_dev)->driver_data) { case ad7314: data = (data & AD7314_TEMP_MASK) >> AD7314_TEMP_OFFSET; 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 &= ADT7301_TEMP_MASK; data = (data << 2) >> 2; return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(data * 3125, 100)); default: return -EINVAL; } } static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ad7314_show_temperature, NULL, 0); static struct attribute *ad7314_attributes[] = { &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 = kzalloc(sizeof(*chip), GFP_KERNEL); if (chip == NULL) { ret = -ENOMEM; goto error_ret; } dev_set_drvdata(&spi_dev->dev, chip); ret = sysfs_create_group(&spi_dev->dev.kobj, &ad7314_group); if (ret < 0) goto error_free_chip; 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; } return 0; error_remove_group: sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group); error_free_chip: kfree(chip); error_ret: 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); kfree(chip); 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 = __devexit_p(ad7314_remove), .id_table = ad7314_id, }; static __init int ad7314_init(void) { return spi_register_driver(&ad7314_driver); } module_init(ad7314_init); static __exit void ad7314_exit(void) { spi_unregister_driver(&ad7314_driver); } module_exit(ad7314_exit); MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>"); MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital" " temperature sensor driver"); MODULE_LICENSE("GPL v2");