WSL2-Linux-Kernel/drivers/hwmon/shtc1.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 09:55:06 +03:00
// SPDX-License-Identifier: GPL-2.0-or-later
/* Sensirion SHTC1 humidity and temperature sensor driver
*
* Copyright (C) 2014 Sensirion AG, Switzerland
* Author: Johannes Winkelmann <johannes.winkelmann@sensirion.com>
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/platform_data/shtc1.h>
/* commands (high precision mode) */
static const unsigned char shtc1_cmd_measure_blocking_hpm[] = { 0x7C, 0xA2 };
static const unsigned char shtc1_cmd_measure_nonblocking_hpm[] = { 0x78, 0x66 };
/* commands (low precision mode) */
static const unsigned char shtc1_cmd_measure_blocking_lpm[] = { 0x64, 0x58 };
static const unsigned char shtc1_cmd_measure_nonblocking_lpm[] = { 0x60, 0x9c };
/* command for reading the ID register */
static const unsigned char shtc1_cmd_read_id_reg[] = { 0xef, 0xc8 };
/*
* constants for reading the ID register
* SHTC1: 0x0007 with mask 0x003f
* SHTW1: 0x0007 with mask 0x003f
* SHTC3: 0x0807 with mask 0x083f
*/
#define SHTC3_ID 0x0807
#define SHTC3_ID_MASK 0x083f
#define SHTC1_ID 0x0007
#define SHTC1_ID_MASK 0x003f
/* delays for non-blocking i2c commands, both in us */
#define SHTC1_NONBLOCKING_WAIT_TIME_HPM 14400
#define SHTC1_NONBLOCKING_WAIT_TIME_LPM 1000
#define SHTC3_NONBLOCKING_WAIT_TIME_HPM 12100
#define SHTC3_NONBLOCKING_WAIT_TIME_LPM 800
#define SHTC1_CMD_LENGTH 2
#define SHTC1_RESPONSE_LENGTH 6
enum shtcx_chips {
shtc1,
shtc3,
};
struct shtc1_data {
struct i2c_client *client;
struct mutex update_lock;
bool valid;
unsigned long last_updated; /* in jiffies */
const unsigned char *command;
unsigned int nonblocking_wait_time; /* in us */
struct shtc1_platform_data setup;
enum shtcx_chips chip;
int temperature; /* 1000 * temperature in dgr C */
int humidity; /* 1000 * relative humidity in %RH */
};
static int shtc1_update_values(struct i2c_client *client,
struct shtc1_data *data,
char *buf, int bufsize)
{
int ret = i2c_master_send(client, data->command, SHTC1_CMD_LENGTH);
if (ret != SHTC1_CMD_LENGTH) {
dev_err(&client->dev, "failed to send command: %d\n", ret);
return ret < 0 ? ret : -EIO;
}
/*
* In blocking mode (clock stretching mode) the I2C bus
* is blocked for other traffic, thus the call to i2c_master_recv()
* will wait until the data is ready. For non blocking mode, we
* have to wait ourselves.
*/
if (!data->setup.blocking_io)
usleep_range(data->nonblocking_wait_time,
data->nonblocking_wait_time + 1000);
ret = i2c_master_recv(client, buf, bufsize);
if (ret != bufsize) {
dev_err(&client->dev, "failed to read values: %d\n", ret);
return ret < 0 ? ret : -EIO;
}
return 0;
}
/* sysfs attributes */
static struct shtc1_data *shtc1_update_client(struct device *dev)
{
struct shtc1_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
unsigned char buf[SHTC1_RESPONSE_LENGTH];
int val;
int ret = 0;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ / 10) || !data->valid) {
ret = shtc1_update_values(client, data, buf, sizeof(buf));
if (ret)
goto out;
/*
* From datasheet:
* T = -45 + 175 * ST / 2^16
* RH = 100 * SRH / 2^16
*
* Adapted for integer fixed point (3 digit) arithmetic.
*/
val = be16_to_cpup((__be16 *)buf);
data->temperature = ((21875 * val) >> 13) - 45000;
val = be16_to_cpup((__be16 *)(buf + 3));
data->humidity = ((12500 * val) >> 13);
data->last_updated = jiffies;
data->valid = true;
}
out:
mutex_unlock(&data->update_lock);
return ret == 0 ? data : ERR_PTR(ret);
}
static ssize_t temp1_input_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct shtc1_data *data = shtc1_update_client(dev);
if (IS_ERR(data))
return PTR_ERR(data);
return sprintf(buf, "%d\n", data->temperature);
}
static ssize_t humidity1_input_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct shtc1_data *data = shtc1_update_client(dev);
if (IS_ERR(data))
return PTR_ERR(data);
return sprintf(buf, "%d\n", data->humidity);
}
static DEVICE_ATTR_RO(temp1_input);
static DEVICE_ATTR_RO(humidity1_input);
static struct attribute *shtc1_attrs[] = {
&dev_attr_temp1_input.attr,
&dev_attr_humidity1_input.attr,
NULL
};
ATTRIBUTE_GROUPS(shtc1);
static void shtc1_select_command(struct shtc1_data *data)
{
if (data->setup.high_precision) {
data->command = data->setup.blocking_io ?
shtc1_cmd_measure_blocking_hpm :
shtc1_cmd_measure_nonblocking_hpm;
data->nonblocking_wait_time = (data->chip == shtc1) ?
SHTC1_NONBLOCKING_WAIT_TIME_HPM :
SHTC3_NONBLOCKING_WAIT_TIME_HPM;
} else {
data->command = data->setup.blocking_io ?
shtc1_cmd_measure_blocking_lpm :
shtc1_cmd_measure_nonblocking_lpm;
data->nonblocking_wait_time = (data->chip == shtc1) ?
SHTC1_NONBLOCKING_WAIT_TIME_LPM :
SHTC3_NONBLOCKING_WAIT_TIME_LPM;
}
}
static const struct i2c_device_id shtc1_id[];
static int shtc1_probe(struct i2c_client *client)
{
int ret;
u16 id_reg;
char id_reg_buf[2];
struct shtc1_data *data;
struct device *hwmon_dev;
enum shtcx_chips chip = i2c_match_id(shtc1_id, client)->driver_data;
struct i2c_adapter *adap = client->adapter;
struct device *dev = &client->dev;
if (!i2c_check_functionality(adap, I2C_FUNC_I2C)) {
dev_err(dev, "plain i2c transactions not supported\n");
return -ENODEV;
}
ret = i2c_master_send(client, shtc1_cmd_read_id_reg, SHTC1_CMD_LENGTH);
if (ret != SHTC1_CMD_LENGTH) {
dev_err(dev, "could not send read_id_reg command: %d\n", ret);
return ret < 0 ? ret : -ENODEV;
}
ret = i2c_master_recv(client, id_reg_buf, sizeof(id_reg_buf));
if (ret != sizeof(id_reg_buf)) {
dev_err(dev, "could not read ID register: %d\n", ret);
return -ENODEV;
}
id_reg = be16_to_cpup((__be16 *)id_reg_buf);
if (chip == shtc3) {
if ((id_reg & SHTC3_ID_MASK) != SHTC3_ID) {
dev_err(dev, "SHTC3 ID register does not match\n");
return -ENODEV;
}
} else if ((id_reg & SHTC1_ID_MASK) != SHTC1_ID) {
dev_err(dev, "SHTC1 ID register does not match\n");
return -ENODEV;
}
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->setup.blocking_io = false;
data->setup.high_precision = true;
data->client = client;
data->chip = chip;
if (client->dev.platform_data)
data->setup = *(struct shtc1_platform_data *)dev->platform_data;
shtc1_select_command(data);
mutex_init(&data->update_lock);
hwmon_dev = devm_hwmon_device_register_with_groups(dev,
client->name,
data,
shtc1_groups);
if (IS_ERR(hwmon_dev))
dev_dbg(dev, "unable to register hwmon device\n");
return PTR_ERR_OR_ZERO(hwmon_dev);
}
/* device ID table */
static const struct i2c_device_id shtc1_id[] = {
{ "shtc1", shtc1 },
{ "shtw1", shtc1 },
{ "shtc3", shtc3 },
{ }
};
MODULE_DEVICE_TABLE(i2c, shtc1_id);
static struct i2c_driver shtc1_i2c_driver = {
.driver.name = "shtc1",
.probe_new = shtc1_probe,
.id_table = shtc1_id,
};
module_i2c_driver(shtc1_i2c_driver);
MODULE_AUTHOR("Johannes Winkelmann <johannes.winkelmann@sensirion.com>");
MODULE_DESCRIPTION("Sensirion SHTC1 humidity and temperature sensor driver");
MODULE_LICENSE("GPL");