linux/drivers/hwmon/pcf8591.c
Thomas Gleixner 74ba9207e1 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61
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 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 you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  675 mass ave cambridge ma 02139 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 441 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520071858.739733335@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:36:45 +02:00

323 lines
7.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2001-2004 Aurelien Jarno <aurelien@aurel32.net>
* Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
* the help of Jean Delvare <jdelvare@suse.de>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/hwmon.h>
/* Insmod parameters */
static int input_mode;
module_param(input_mode, int, 0);
MODULE_PARM_DESC(input_mode,
"Analog input mode:\n"
" 0 = four single ended inputs\n"
" 1 = three differential inputs\n"
" 2 = single ended and differential mixed\n"
" 3 = two differential inputs\n");
/*
* The PCF8591 control byte
* 7 6 5 4 3 2 1 0
* | 0 |AOEF| AIP | 0 |AINC| AICH |
*/
/* Analog Output Enable Flag (analog output active if 1) */
#define PCF8591_CONTROL_AOEF 0x40
/*
* Analog Input Programming
* 0x00 = four single ended inputs
* 0x10 = three differential inputs
* 0x20 = single ended and differential mixed
* 0x30 = two differential inputs
*/
#define PCF8591_CONTROL_AIP_MASK 0x30
/* Autoincrement Flag (switch on if 1) */
#define PCF8591_CONTROL_AINC 0x04
/*
* Channel selection
* 0x00 = channel 0
* 0x01 = channel 1
* 0x02 = channel 2
* 0x03 = channel 3
*/
#define PCF8591_CONTROL_AICH_MASK 0x03
/* Initial values */
#define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF)
#define PCF8591_INIT_AOUT 0 /* DAC out = 0 */
/* Conversions */
#define REG_TO_SIGNED(reg) (((reg) & 0x80) ? ((reg) - 256) : (reg))
struct pcf8591_data {
struct device *hwmon_dev;
struct mutex update_lock;
u8 control;
u8 aout;
};
static void pcf8591_init_client(struct i2c_client *client);
static int pcf8591_read_channel(struct device *dev, int channel);
/* following are the sysfs callback functions */
#define show_in_channel(channel) \
static ssize_t show_in##channel##_input(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\
} \
static DEVICE_ATTR(in##channel##_input, S_IRUGO, \
show_in##channel##_input, NULL);
show_in_channel(0);
show_in_channel(1);
show_in_channel(2);
show_in_channel(3);
static ssize_t out0_output_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
return sprintf(buf, "%d\n", data->aout * 10);
}
static ssize_t out0_output_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
unsigned long val;
struct i2c_client *client = to_i2c_client(dev);
struct pcf8591_data *data = i2c_get_clientdata(client);
int err;
err = kstrtoul(buf, 10, &val);
if (err)
return err;
val /= 10;
if (val > 255)
return -EINVAL;
data->aout = val;
i2c_smbus_write_byte_data(client, data->control, data->aout);
return count;
}
static DEVICE_ATTR_RW(out0_output);
static ssize_t out0_enable_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));
}
static ssize_t out0_enable_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct pcf8591_data *data = i2c_get_clientdata(client);
unsigned long val;
int err;
err = kstrtoul(buf, 10, &val);
if (err)
return err;
mutex_lock(&data->update_lock);
if (val)
data->control |= PCF8591_CONTROL_AOEF;
else
data->control &= ~PCF8591_CONTROL_AOEF;
i2c_smbus_write_byte(client, data->control);
mutex_unlock(&data->update_lock);
return count;
}
static DEVICE_ATTR_RW(out0_enable);
static struct attribute *pcf8591_attributes[] = {
&dev_attr_out0_enable.attr,
&dev_attr_out0_output.attr,
&dev_attr_in0_input.attr,
&dev_attr_in1_input.attr,
NULL
};
static const struct attribute_group pcf8591_attr_group = {
.attrs = pcf8591_attributes,
};
static struct attribute *pcf8591_attributes_opt[] = {
&dev_attr_in2_input.attr,
&dev_attr_in3_input.attr,
NULL
};
static const struct attribute_group pcf8591_attr_group_opt = {
.attrs = pcf8591_attributes_opt,
};
/*
* Real code
*/
static int pcf8591_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pcf8591_data *data;
int err;
data = devm_kzalloc(&client->dev, sizeof(struct pcf8591_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
/* Initialize the PCF8591 chip */
pcf8591_init_client(client);
/* Register sysfs hooks */
err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group);
if (err)
return err;
/* Register input2 if not in "two differential inputs" mode */
if (input_mode != 3) {
err = device_create_file(&client->dev, &dev_attr_in2_input);
if (err)
goto exit_sysfs_remove;
}
/* Register input3 only in "four single ended inputs" mode */
if (input_mode == 0) {
err = device_create_file(&client->dev, &dev_attr_in3_input);
if (err)
goto exit_sysfs_remove;
}
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_sysfs_remove;
}
return 0;
exit_sysfs_remove:
sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
return err;
}
static int pcf8591_remove(struct i2c_client *client)
{
struct pcf8591_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
return 0;
}
/* Called when we have found a new PCF8591. */
static void pcf8591_init_client(struct i2c_client *client)
{
struct pcf8591_data *data = i2c_get_clientdata(client);
data->control = PCF8591_INIT_CONTROL;
data->aout = PCF8591_INIT_AOUT;
i2c_smbus_write_byte_data(client, data->control, data->aout);
/*
* The first byte transmitted contains the conversion code of the
* previous read cycle. FLUSH IT!
*/
i2c_smbus_read_byte(client);
}
static int pcf8591_read_channel(struct device *dev, int channel)
{
u8 value;
struct i2c_client *client = to_i2c_client(dev);
struct pcf8591_data *data = i2c_get_clientdata(client);
mutex_lock(&data->update_lock);
if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {
data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)
| channel;
i2c_smbus_write_byte(client, data->control);
/*
* The first byte transmitted contains the conversion code of
* the previous read cycle. FLUSH IT!
*/
i2c_smbus_read_byte(client);
}
value = i2c_smbus_read_byte(client);
mutex_unlock(&data->update_lock);
if ((channel == 2 && input_mode == 2) ||
(channel != 3 && (input_mode == 1 || input_mode == 3)))
return 10 * REG_TO_SIGNED(value);
else
return 10 * value;
}
static const struct i2c_device_id pcf8591_id[] = {
{ "pcf8591", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pcf8591_id);
static struct i2c_driver pcf8591_driver = {
.driver = {
.name = "pcf8591",
},
.probe = pcf8591_probe,
.remove = pcf8591_remove,
.id_table = pcf8591_id,
};
static int __init pcf8591_init(void)
{
if (input_mode < 0 || input_mode > 3) {
pr_warn("invalid input_mode (%d)\n", input_mode);
input_mode = 0;
}
return i2c_add_driver(&pcf8591_driver);
}
static void __exit pcf8591_exit(void)
{
i2c_del_driver(&pcf8591_driver);
}
MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
MODULE_DESCRIPTION("PCF8591 driver");
MODULE_LICENSE("GPL");
module_init(pcf8591_init);
module_exit(pcf8591_exit);