cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ad7314.c (3041B)

      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
     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 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
     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");