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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tmp117.c (4399B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Digital temperature sensor with integrated Non-volatile memory
      4 * Copyright (c) 2021 Puranjay Mohan <puranjay12@gmail.com>
      5 *
      6 * Driver for the Texas Instruments TMP117 Temperature Sensor
      7 * (7-bit I2C slave address (0x48 - 0x4B), changeable via ADD pins)
      8 *
      9 * Note: This driver assumes that the sensor has been calibrated beforehand.
     10 */
     11
     12#include <linux/err.h>
     13#include <linux/i2c.h>
     14#include <linux/module.h>
     15#include <linux/bitops.h>
     16#include <linux/types.h>
     17#include <linux/kernel.h>
     18#include <linux/limits.h>
     19
     20#include <linux/iio/iio.h>
     21
     22#define TMP117_REG_TEMP			0x0
     23#define TMP117_REG_CFGR			0x1
     24#define TMP117_REG_HIGH_LIM		0x2
     25#define TMP117_REG_LOW_LIM		0x3
     26#define TMP117_REG_EEPROM_UL		0x4
     27#define TMP117_REG_EEPROM1		0x5
     28#define TMP117_REG_EEPROM2		0x6
     29#define TMP117_REG_TEMP_OFFSET		0x7
     30#define TMP117_REG_EEPROM3		0x8
     31#define TMP117_REG_DEVICE_ID		0xF
     32
     33#define TMP117_RESOLUTION_10UC		78125
     34#define TMP117_DEVICE_ID		0x0117
     35#define MICRODEGREE_PER_10MILLIDEGREE	10000
     36
     37struct tmp117_data {
     38	struct i2c_client *client;
     39	s16 calibbias;
     40};
     41
     42static int tmp117_read_raw(struct iio_dev *indio_dev,
     43		struct iio_chan_spec const *channel, int *val,
     44		int *val2, long mask)
     45{
     46	struct tmp117_data *data = iio_priv(indio_dev);
     47	s32 ret;
     48
     49	switch (mask) {
     50	case IIO_CHAN_INFO_RAW:
     51		ret = i2c_smbus_read_word_swapped(data->client,
     52						TMP117_REG_TEMP);
     53		if (ret < 0)
     54			return ret;
     55		*val = sign_extend32(ret, 15);
     56		return IIO_VAL_INT;
     57
     58	case IIO_CHAN_INFO_CALIBBIAS:
     59		ret = i2c_smbus_read_word_swapped(data->client,
     60					TMP117_REG_TEMP_OFFSET);
     61		if (ret < 0)
     62			return ret;
     63		*val = sign_extend32(ret, 15);
     64		return IIO_VAL_INT;
     65
     66	case IIO_CHAN_INFO_SCALE:
     67		/*
     68		 * Conversion from 10s of uC to mC
     69		 * as IIO reports temperature in mC
     70		 */
     71		*val = TMP117_RESOLUTION_10UC / MICRODEGREE_PER_10MILLIDEGREE;
     72		*val2 = (TMP117_RESOLUTION_10UC %
     73					MICRODEGREE_PER_10MILLIDEGREE) * 100;
     74
     75		return IIO_VAL_INT_PLUS_MICRO;
     76
     77	default:
     78		return -EINVAL;
     79	}
     80}
     81
     82static int tmp117_write_raw(struct iio_dev *indio_dev,
     83		struct iio_chan_spec const *channel, int val,
     84		int val2, long mask)
     85{
     86	struct tmp117_data *data = iio_priv(indio_dev);
     87	s16 off;
     88
     89	switch (mask) {
     90	case IIO_CHAN_INFO_CALIBBIAS:
     91		off = clamp_t(int, val, S16_MIN, S16_MAX);
     92		if (off == data->calibbias)
     93			return 0;
     94		data->calibbias = off;
     95		return i2c_smbus_write_word_swapped(data->client,
     96						TMP117_REG_TEMP_OFFSET, off);
     97
     98	default:
     99		return -EINVAL;
    100	}
    101}
    102
    103static const struct iio_chan_spec tmp117_channels[] = {
    104	{
    105		.type = IIO_TEMP,
    106		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
    107			BIT(IIO_CHAN_INFO_CALIBBIAS) | BIT(IIO_CHAN_INFO_SCALE),
    108	},
    109};
    110
    111static const struct iio_info tmp117_info = {
    112	.read_raw = tmp117_read_raw,
    113	.write_raw = tmp117_write_raw,
    114};
    115
    116static int tmp117_identify(struct i2c_client *client)
    117{
    118	int dev_id;
    119
    120	dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
    121	if (dev_id < 0)
    122		return dev_id;
    123	if (dev_id != TMP117_DEVICE_ID) {
    124		dev_err(&client->dev, "TMP117 not found\n");
    125		return -ENODEV;
    126	}
    127	return 0;
    128}
    129
    130static int tmp117_probe(struct i2c_client *client)
    131{
    132	struct tmp117_data *data;
    133	struct iio_dev *indio_dev;
    134	int ret;
    135
    136	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
    137		return -EOPNOTSUPP;
    138
    139	ret = tmp117_identify(client);
    140	if (ret < 0)
    141		return ret;
    142
    143	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
    144	if (!indio_dev)
    145		return -ENOMEM;
    146
    147	data = iio_priv(indio_dev);
    148	data->client = client;
    149	data->calibbias = 0;
    150
    151	indio_dev->name = "tmp117";
    152	indio_dev->modes = INDIO_DIRECT_MODE;
    153	indio_dev->info = &tmp117_info;
    154
    155	indio_dev->channels = tmp117_channels;
    156	indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
    157
    158	return devm_iio_device_register(&client->dev, indio_dev);
    159}
    160
    161static const struct of_device_id tmp117_of_match[] = {
    162	{ .compatible = "ti,tmp117", },
    163	{ }
    164};
    165MODULE_DEVICE_TABLE(of, tmp117_of_match);
    166
    167static const struct i2c_device_id tmp117_id[] = {
    168	{ "tmp117", 0 },
    169	{ }
    170};
    171MODULE_DEVICE_TABLE(i2c, tmp117_id);
    172
    173static struct i2c_driver tmp117_driver = {
    174	.driver = {
    175		.name	= "tmp117",
    176		.of_match_table = tmp117_of_match,
    177	},
    178	.probe_new	= tmp117_probe,
    179	.id_table	= tmp117_id,
    180};
    181module_i2c_driver(tmp117_driver);
    182
    183MODULE_AUTHOR("Puranjay Mohan <puranjay12@gmail.com>");
    184MODULE_DESCRIPTION("TI TMP117 Temperature sensor driver");
    185MODULE_LICENSE("GPL");