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linux-next/drivers/hwmon/ads1015.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

325 lines
7.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ads1015.c - lm_sensors driver for ads1015 12-bit 4-input ADC
* (C) Copyright 2010
* Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
*
* Based on the ads7828 driver by Steve Hardy.
*
* Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads1015.pdf
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/of.h>
#include <linux/platform_data/ads1015.h>
/* ADS1015 registers */
enum {
ADS1015_CONVERSION = 0,
ADS1015_CONFIG = 1,
};
/* PGA fullscale voltages in mV */
static const unsigned int fullscale_table[8] = {
6144, 4096, 2048, 1024, 512, 256, 256, 256 };
/* Data rates in samples per second */
static const unsigned int data_rate_table_1015[8] = {
128, 250, 490, 920, 1600, 2400, 3300, 3300
};
static const unsigned int data_rate_table_1115[8] = {
8, 16, 32, 64, 128, 250, 475, 860
};
#define ADS1015_DEFAULT_CHANNELS 0xff
#define ADS1015_DEFAULT_PGA 2
#define ADS1015_DEFAULT_DATA_RATE 4
enum ads1015_chips {
ads1015,
ads1115,
};
struct ads1015_data {
struct device *hwmon_dev;
struct mutex update_lock; /* mutex protect updates */
struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
enum ads1015_chips id;
};
static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
{
u16 config;
struct ads1015_data *data = i2c_get_clientdata(client);
unsigned int pga = data->channel_data[channel].pga;
unsigned int data_rate = data->channel_data[channel].data_rate;
unsigned int conversion_time_ms;
const unsigned int * const rate_table = data->id == ads1115 ?
data_rate_table_1115 : data_rate_table_1015;
int res;
mutex_lock(&data->update_lock);
/* get channel parameters */
res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
if (res < 0)
goto err_unlock;
config = res;
conversion_time_ms = DIV_ROUND_UP(1000, rate_table[data_rate]);
/* setup and start single conversion */
config &= 0x001f;
config |= (1 << 15) | (1 << 8);
config |= (channel & 0x0007) << 12;
config |= (pga & 0x0007) << 9;
config |= (data_rate & 0x0007) << 5;
res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config);
if (res < 0)
goto err_unlock;
/* wait until conversion finished */
msleep(conversion_time_ms);
res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
if (res < 0)
goto err_unlock;
config = res;
if (!(config & (1 << 15))) {
/* conversion not finished in time */
res = -EIO;
goto err_unlock;
}
res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
err_unlock:
mutex_unlock(&data->update_lock);
return res;
}
static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel,
s16 reg)
{
struct ads1015_data *data = i2c_get_clientdata(client);
unsigned int pga = data->channel_data[channel].pga;
int fullscale = fullscale_table[pga];
const int mask = data->id == ads1115 ? 0x7fff : 0x7ff0;
return DIV_ROUND_CLOSEST(reg * fullscale, mask);
}
/* sysfs callback function */
static ssize_t in_show(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
int res;
int index = attr->index;
res = ads1015_read_adc(client, index);
if (res < 0)
return res;
return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res));
}
static const struct sensor_device_attribute ads1015_in[] = {
SENSOR_ATTR_RO(in0_input, in, 0),
SENSOR_ATTR_RO(in1_input, in, 1),
SENSOR_ATTR_RO(in2_input, in, 2),
SENSOR_ATTR_RO(in3_input, in, 3),
SENSOR_ATTR_RO(in4_input, in, 4),
SENSOR_ATTR_RO(in5_input, in, 5),
SENSOR_ATTR_RO(in6_input, in, 6),
SENSOR_ATTR_RO(in7_input, in, 7),
};
/*
* Driver interface
*/
static int ads1015_remove(struct i2c_client *client)
{
struct ads1015_data *data = i2c_get_clientdata(client);
int k;
hwmon_device_unregister(data->hwmon_dev);
for (k = 0; k < ADS1015_CHANNELS; ++k)
device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
return 0;
}
#ifdef CONFIG_OF
static int ads1015_get_channels_config_of(struct i2c_client *client)
{
struct ads1015_data *data = i2c_get_clientdata(client);
struct device_node *node;
if (!client->dev.of_node
|| !of_get_next_child(client->dev.of_node, NULL))
return -EINVAL;
for_each_child_of_node(client->dev.of_node, node) {
u32 pval;
unsigned int channel;
unsigned int pga = ADS1015_DEFAULT_PGA;
unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
if (of_property_read_u32(node, "reg", &pval)) {
dev_err(&client->dev, "invalid reg on %pOF\n", node);
continue;
}
channel = pval;
if (channel >= ADS1015_CHANNELS) {
dev_err(&client->dev,
"invalid channel index %d on %pOF\n",
channel, node);
continue;
}
if (!of_property_read_u32(node, "ti,gain", &pval)) {
pga = pval;
if (pga > 6) {
dev_err(&client->dev, "invalid gain on %pOF\n",
node);
return -EINVAL;
}
}
if (!of_property_read_u32(node, "ti,datarate", &pval)) {
data_rate = pval;
if (data_rate > 7) {
dev_err(&client->dev,
"invalid data_rate on %pOF\n", node);
return -EINVAL;
}
}
data->channel_data[channel].enabled = true;
data->channel_data[channel].pga = pga;
data->channel_data[channel].data_rate = data_rate;
}
return 0;
}
#endif
static void ads1015_get_channels_config(struct i2c_client *client)
{
unsigned int k;
struct ads1015_data *data = i2c_get_clientdata(client);
struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
/* prefer platform data */
if (pdata) {
memcpy(data->channel_data, pdata->channel_data,
sizeof(data->channel_data));
return;
}
#ifdef CONFIG_OF
if (!ads1015_get_channels_config_of(client))
return;
#endif
/* fallback on default configuration */
for (k = 0; k < ADS1015_CHANNELS; ++k) {
data->channel_data[k].enabled = true;
data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
}
}
static int ads1015_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ads1015_data *data;
int err;
unsigned int k;
data = devm_kzalloc(&client->dev, sizeof(struct ads1015_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
if (client->dev.of_node)
data->id = (enum ads1015_chips)
of_device_get_match_data(&client->dev);
else
data->id = id->driver_data;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
/* build sysfs attribute group */
ads1015_get_channels_config(client);
for (k = 0; k < ADS1015_CHANNELS; ++k) {
if (!data->channel_data[k].enabled)
continue;
err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
if (err)
goto exit_remove;
}
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove;
}
return 0;
exit_remove:
for (k = 0; k < ADS1015_CHANNELS; ++k)
device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
return err;
}
static const struct i2c_device_id ads1015_id[] = {
{ "ads1015", ads1015},
{ "ads1115", ads1115},
{ }
};
MODULE_DEVICE_TABLE(i2c, ads1015_id);
static const struct of_device_id __maybe_unused ads1015_of_match[] = {
{
.compatible = "ti,ads1015",
.data = (void *)ads1015
},
{
.compatible = "ti,ads1115",
.data = (void *)ads1115
},
{ },
};
MODULE_DEVICE_TABLE(of, ads1015_of_match);
static struct i2c_driver ads1015_driver = {
.driver = {
.name = "ads1015",
.of_match_table = of_match_ptr(ads1015_of_match),
},
.probe = ads1015_probe,
.remove = ads1015_remove,
.id_table = ads1015_id,
};
module_i2c_driver(ads1015_driver);
MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
MODULE_DESCRIPTION("ADS1015 driver");
MODULE_LICENSE("GPL");