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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
173 lines
3.7 KiB
C
173 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* An hwmon driver for the Microchip TC74
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*
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* Copyright 2015 Maciej Szmigiero <mail@maciej.szmigiero.name>
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*
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* Based on ad7414.c:
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* Copyright 2006 Stefan Roese, DENX Software Engineering
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* Copyright 2008 Sean MacLennan, PIKA Technologies
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* Copyright 2008 Frank Edelhaeuser, Spansion Inc.
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*/
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#include <linux/bitops.h>
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#include <linux/err.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/i2c.h>
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#include <linux/jiffies.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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/* TC74 registers */
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#define TC74_REG_TEMP 0x00
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#define TC74_REG_CONFIG 0x01
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struct tc74_data {
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struct i2c_client *client;
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struct mutex lock; /* atomic read data updates */
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bool valid; /* validity of fields below */
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unsigned long next_update; /* In jiffies */
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s8 temp_input; /* Temp value in dC */
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};
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static int tc74_update_device(struct device *dev)
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{
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struct tc74_data *data = dev_get_drvdata(dev);
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struct i2c_client *client = data->client;
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int ret;
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ret = mutex_lock_interruptible(&data->lock);
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if (ret)
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return ret;
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if (time_after(jiffies, data->next_update) || !data->valid) {
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s32 value;
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value = i2c_smbus_read_byte_data(client, TC74_REG_CONFIG);
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if (value < 0) {
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dev_dbg(&client->dev, "TC74_REG_CONFIG read err %d\n",
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(int)value);
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ret = value;
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goto ret_unlock;
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}
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if (!(value & BIT(6))) {
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/* not ready yet */
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ret = -EAGAIN;
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goto ret_unlock;
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}
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value = i2c_smbus_read_byte_data(client, TC74_REG_TEMP);
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if (value < 0) {
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dev_dbg(&client->dev, "TC74_REG_TEMP read err %d\n",
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(int)value);
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ret = value;
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goto ret_unlock;
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}
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data->temp_input = value;
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data->next_update = jiffies + HZ / 4;
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data->valid = true;
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}
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ret_unlock:
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mutex_unlock(&data->lock);
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return ret;
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}
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static ssize_t temp_input_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct tc74_data *data = dev_get_drvdata(dev);
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int ret;
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ret = tc74_update_device(dev);
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if (ret)
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return ret;
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return sprintf(buf, "%d\n", data->temp_input * 1000);
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}
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static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
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static struct attribute *tc74_attrs[] = {
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&sensor_dev_attr_temp1_input.dev_attr.attr,
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NULL
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};
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ATTRIBUTE_GROUPS(tc74);
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static int tc74_probe(struct i2c_client *client,
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const struct i2c_device_id *dev_id)
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{
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struct device *dev = &client->dev;
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struct tc74_data *data;
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struct device *hwmon_dev;
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s32 conf;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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return -EOPNOTSUPP;
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data = devm_kzalloc(dev, sizeof(struct tc74_data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->client = client;
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mutex_init(&data->lock);
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/* Make sure the chip is powered up. */
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conf = i2c_smbus_read_byte_data(client, TC74_REG_CONFIG);
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if (conf < 0) {
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dev_err(dev, "unable to read config register\n");
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return conf;
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}
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if (conf & 0x3f) {
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dev_err(dev, "invalid config register value\n");
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return -ENODEV;
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}
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if (conf & BIT(7)) {
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s32 ret;
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conf &= ~BIT(7);
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ret = i2c_smbus_write_byte_data(client, TC74_REG_CONFIG, conf);
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if (ret)
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dev_warn(dev, "unable to disable STANDBY\n");
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}
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hwmon_dev = devm_hwmon_device_register_with_groups(dev,
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client->name,
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data, tc74_groups);
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return PTR_ERR_OR_ZERO(hwmon_dev);
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}
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static const struct i2c_device_id tc74_id[] = {
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{ "tc74", 0 },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, tc74_id);
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static struct i2c_driver tc74_driver = {
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.driver = {
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.name = "tc74",
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},
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.probe = tc74_probe,
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.id_table = tc74_id,
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};
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module_i2c_driver(tc74_driver);
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MODULE_AUTHOR("Maciej Szmigiero <mail@maciej.szmigiero.name>");
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MODULE_DESCRIPTION("TC74 driver");
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MODULE_LICENSE("GPL");
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