// SPDX-License-Identifier: GPL-2.0-or-later /* * AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302 * * Copyright 2010 Analog Devices Inc. * * 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> #include <linux/bitops.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; 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_temperature_show(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 = sign_extend32(data, 9); 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 = sign_extend32(data, 13); return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(data * 3125, 100)); default: return -EINVAL; } } static SENSOR_DEVICE_ATTR_RO(temp1_input, ad7314_temperature, 0); static struct attribute *ad7314_attrs[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, NULL, }; ATTRIBUTE_GROUPS(ad7314); static int ad7314_probe(struct spi_device *spi_dev) { struct ad7314_data *chip; struct device *hwmon_dev; chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL); if (chip == NULL) return -ENOMEM; chip->spi_dev = spi_dev; hwmon_dev = devm_hwmon_device_register_with_groups(&spi_dev->dev, spi_dev->modalias, chip, ad7314_groups); return PTR_ERR_OR_ZERO(hwmon_dev); } 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", }, .probe = ad7314_probe, .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");