135 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT73024 *5 * Copyright 2010 Analog Devices Inc.6 *7 * Conversion to hwmon from IIO done by Jonathan Cameron <jic23@cam.ac.uk>8 */9#include <linux/device.h>10#include <linux/kernel.h>11#include <linux/slab.h>12#include <linux/sysfs.h>13#include <linux/spi/spi.h>14#include <linux/module.h>15#include <linux/err.h>16#include <linux/hwmon.h>17#include <linux/hwmon-sysfs.h>18#include <linux/bitops.h>19 20/*21 * AD7314 temperature masks22 */23#define AD7314_TEMP_MASK 0x7FE024#define AD7314_TEMP_SHIFT 525 26/*27 * ADT7301 and ADT7302 temperature masks28 */29#define ADT7301_TEMP_MASK 0x3FFF30 31enum ad7314_variant {32 adt7301,33 adt7302,34 ad7314,35};36 37struct ad7314_data {38 struct spi_device *spi_dev;39 u16 rx ____cacheline_aligned;40};41 42static int ad7314_spi_read(struct ad7314_data *chip)43{44 int ret;45 46 ret = spi_read(chip->spi_dev, (u8 *)&chip->rx, sizeof(chip->rx));47 if (ret < 0) {48 dev_err(&chip->spi_dev->dev, "SPI read error\n");49 return ret;50 }51 52 return be16_to_cpu(chip->rx);53}54 55static ssize_t ad7314_temperature_show(struct device *dev,56 struct device_attribute *attr,57 char *buf)58{59 struct ad7314_data *chip = dev_get_drvdata(dev);60 s16 data;61 int ret;62 63 ret = ad7314_spi_read(chip);64 if (ret < 0)65 return ret;66 switch (spi_get_device_id(chip->spi_dev)->driver_data) {67 case ad7314:68 data = (ret & AD7314_TEMP_MASK) >> AD7314_TEMP_SHIFT;69 data = sign_extend32(data, 9);70 71 return sprintf(buf, "%d\n", 250 * data);72 case adt7301:73 case adt7302:74 /*75 * Documented as a 13 bit twos complement register76 * with a sign bit - which is a 14 bit 2's complement77 * register. 1lsb - 31.25 milli degrees centigrade78 */79 data = ret & ADT7301_TEMP_MASK;80 data = sign_extend32(data, 13);81 82 return sprintf(buf, "%d\n",83 DIV_ROUND_CLOSEST(data * 3125, 100));84 default:85 return -EINVAL;86 }87}88 89static SENSOR_DEVICE_ATTR_RO(temp1_input, ad7314_temperature, 0);90 91static struct attribute *ad7314_attrs[] = {92 &sensor_dev_attr_temp1_input.dev_attr.attr,93 NULL,94};95 96ATTRIBUTE_GROUPS(ad7314);97 98static int ad7314_probe(struct spi_device *spi_dev)99{100 struct ad7314_data *chip;101 struct device *hwmon_dev;102 103 chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL);104 if (chip == NULL)105 return -ENOMEM;106 107 chip->spi_dev = spi_dev;108 hwmon_dev = devm_hwmon_device_register_with_groups(&spi_dev->dev,109 spi_dev->modalias,110 chip, ad7314_groups);111 return PTR_ERR_OR_ZERO(hwmon_dev);112}113 114static const struct spi_device_id ad7314_id[] = {115 { "adt7301", adt7301 },116 { "adt7302", adt7302 },117 { "ad7314", ad7314 },118 { }119};120MODULE_DEVICE_TABLE(spi, ad7314_id);121 122static struct spi_driver ad7314_driver = {123 .driver = {124 .name = "ad7314",125 },126 .probe = ad7314_probe,127 .id_table = ad7314_id,128};129 130module_spi_driver(ad7314_driver);131 132MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");133MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital temperature sensor driver");134MODULE_LICENSE("GPL v2");135