1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302 4 * 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 masks 22 */ 23 #define AD7314_TEMP_MASK 0x7FE0 24 #define AD7314_TEMP_SHIFT 5 25 26 /* 27 * ADT7301 and ADT7302 temperature masks 28 */ 29 #define ADT7301_TEMP_MASK 0x3FFF 30 31 enum ad7314_variant { 32 adt7301, 33 adt7302, 34 ad7314, 35 }; 36 37 struct ad7314_data { 38 struct spi_device *spi_dev; 39 u16 rx ____cacheline_aligned; 40 }; 41 ad7314_spi_read(struct ad7314_data * chip)42 static 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 ad7314_temperature_show(struct device * dev,struct device_attribute * attr,char * buf)55 static 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 register 76 * with a sign bit - which is a 14 bit 2's complement 77 * register. 1lsb - 31.25 milli degrees centigrade 78 */ 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 89 static SENSOR_DEVICE_ATTR_RO(temp1_input, ad7314_temperature, 0); 90 91 static struct attribute *ad7314_attrs[] = { 92 &sensor_dev_attr_temp1_input.dev_attr.attr, 93 NULL, 94 }; 95 96 ATTRIBUTE_GROUPS(ad7314); 97 ad7314_probe(struct spi_device * spi_dev)98 static 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 } 113 114 static const struct spi_device_id ad7314_id[] = { 115 { "adt7301", adt7301 }, 116 { "adt7302", adt7302 }, 117 { "ad7314", ad7314 }, 118 { } 119 }; 120 MODULE_DEVICE_TABLE(spi, ad7314_id); 121 122 static struct spi_driver ad7314_driver = { 123 .driver = { 124 .name = "ad7314", 125 }, 126 .probe = ad7314_probe, 127 .id_table = ad7314_id, 128 }; 129 130 module_spi_driver(ad7314_driver); 131 132 MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>"); 133 MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital temperature sensor driver"); 134 MODULE_LICENSE("GPL v2"); 135