https://github.com/torvalds/linux
Tip revision: 694d0d0bb2030d2e36df73e2d23d5770511dbc8d authored by Linus Torvalds on 15 August 2016, 02:11:36 UTC
Linux 4.8-rc2
Linux 4.8-rc2
Tip revision: 694d0d0
powr1220.c
/*
* powr1220.c - Driver for the Lattice POWR1220 programmable power supply
* and monitor. Users can read all ADC inputs along with their labels
* using the sysfs nodes.
*
* Copyright (c) 2014 Echo360 http://www.echo360.com
* Scott Kanowitz <skanowitz@echo360.com> <scott.kanowitz@gmail.com>
*
* 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.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#define ADC_STEP_MV 2
#define ADC_MAX_LOW_MEASUREMENT_MV 2000
enum powr1220_regs {
VMON_STATUS0,
VMON_STATUS1,
VMON_STATUS2,
OUTPUT_STATUS0,
OUTPUT_STATUS1,
OUTPUT_STATUS2,
INPUT_STATUS,
ADC_VALUE_LOW,
ADC_VALUE_HIGH,
ADC_MUX,
UES_BYTE0,
UES_BYTE1,
UES_BYTE2,
UES_BYTE3,
GP_OUTPUT1,
GP_OUTPUT2,
GP_OUTPUT3,
INPUT_VALUE,
RESET,
TRIM1_TRIM,
TRIM2_TRIM,
TRIM3_TRIM,
TRIM4_TRIM,
TRIM5_TRIM,
TRIM6_TRIM,
TRIM7_TRIM,
TRIM8_TRIM,
MAX_POWR1220_REGS
};
enum powr1220_adc_values {
VMON1,
VMON2,
VMON3,
VMON4,
VMON5,
VMON6,
VMON7,
VMON8,
VMON9,
VMON10,
VMON11,
VMON12,
VCCA,
VCCINP,
MAX_POWR1220_ADC_VALUES
};
struct powr1220_data {
struct i2c_client *client;
struct mutex update_lock;
bool adc_valid[MAX_POWR1220_ADC_VALUES];
/* the next value is in jiffies */
unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES];
/* values */
int adc_maxes[MAX_POWR1220_ADC_VALUES];
int adc_values[MAX_POWR1220_ADC_VALUES];
};
static const char * const input_names[] = {
[VMON1] = "vmon1",
[VMON2] = "vmon2",
[VMON3] = "vmon3",
[VMON4] = "vmon4",
[VMON5] = "vmon5",
[VMON6] = "vmon6",
[VMON7] = "vmon7",
[VMON8] = "vmon8",
[VMON9] = "vmon9",
[VMON10] = "vmon10",
[VMON11] = "vmon11",
[VMON12] = "vmon12",
[VCCA] = "vcca",
[VCCINP] = "vccinp",
};
/* Reads the specified ADC channel */
static int powr1220_read_adc(struct device *dev, int ch_num)
{
struct powr1220_data *data = dev_get_drvdata(dev);
int reading;
int result;
int adc_range = 0;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
!data->adc_valid[ch_num]) {
/*
* figure out if we need to use the attenuator for
* high inputs or inputs that we don't yet have a measurement
* for. We dynamically set the attenuator depending on the
* max reading.
*/
if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV ||
data->adc_maxes[ch_num] == 0)
adc_range = 1 << 4;
/* set the attenuator and mux */
result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
adc_range | ch_num);
if (result)
goto exit;
/*
* wait at least Tconvert time (200 us) for the
* conversion to complete
*/
udelay(200);
/* get the ADC reading */
result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW);
if (result < 0)
goto exit;
reading = result >> 4;
/* get the upper half of the reading */
result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH);
if (result < 0)
goto exit;
reading |= result << 4;
/* now convert the reading to a voltage */
reading *= ADC_STEP_MV;
data->adc_values[ch_num] = reading;
data->adc_valid[ch_num] = true;
data->adc_last_updated[ch_num] = jiffies;
result = reading;
if (reading > data->adc_maxes[ch_num])
data->adc_maxes[ch_num] = reading;
} else {
result = data->adc_values[ch_num];
}
exit:
mutex_unlock(&data->update_lock);
return result;
}
/* Shows the voltage associated with the specified ADC channel */
static ssize_t powr1220_show_voltage(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
int adc_val = powr1220_read_adc(dev, attr->index);
if (adc_val < 0)
return adc_val;
return sprintf(buf, "%d\n", adc_val);
}
/* Shows the maximum setting associated with the specified ADC channel */
static ssize_t powr1220_show_max(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
struct powr1220_data *data = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", data->adc_maxes[attr->index]);
}
/* Shows the label associated with the specified ADC channel */
static ssize_t powr1220_show_label(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
return sprintf(buf, "%s\n", input_names[attr->index]);
}
static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON1);
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON2);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON3);
static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON4);
static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON5);
static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON6);
static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON7);
static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON8);
static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON9);
static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON10);
static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON11);
static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, powr1220_show_voltage, NULL,
VMON12);
static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, powr1220_show_voltage, NULL,
VCCA);
static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, powr1220_show_voltage, NULL,
VCCINP);
static SENSOR_DEVICE_ATTR(in0_highest, S_IRUGO, powr1220_show_max, NULL,
VMON1);
static SENSOR_DEVICE_ATTR(in1_highest, S_IRUGO, powr1220_show_max, NULL,
VMON2);
static SENSOR_DEVICE_ATTR(in2_highest, S_IRUGO, powr1220_show_max, NULL,
VMON3);
static SENSOR_DEVICE_ATTR(in3_highest, S_IRUGO, powr1220_show_max, NULL,
VMON4);
static SENSOR_DEVICE_ATTR(in4_highest, S_IRUGO, powr1220_show_max, NULL,
VMON5);
static SENSOR_DEVICE_ATTR(in5_highest, S_IRUGO, powr1220_show_max, NULL,
VMON6);
static SENSOR_DEVICE_ATTR(in6_highest, S_IRUGO, powr1220_show_max, NULL,
VMON7);
static SENSOR_DEVICE_ATTR(in7_highest, S_IRUGO, powr1220_show_max, NULL,
VMON8);
static SENSOR_DEVICE_ATTR(in8_highest, S_IRUGO, powr1220_show_max, NULL,
VMON9);
static SENSOR_DEVICE_ATTR(in9_highest, S_IRUGO, powr1220_show_max, NULL,
VMON10);
static SENSOR_DEVICE_ATTR(in10_highest, S_IRUGO, powr1220_show_max, NULL,
VMON11);
static SENSOR_DEVICE_ATTR(in11_highest, S_IRUGO, powr1220_show_max, NULL,
VMON12);
static SENSOR_DEVICE_ATTR(in12_highest, S_IRUGO, powr1220_show_max, NULL,
VCCA);
static SENSOR_DEVICE_ATTR(in13_highest, S_IRUGO, powr1220_show_max, NULL,
VCCINP);
static SENSOR_DEVICE_ATTR(in0_label, S_IRUGO, powr1220_show_label, NULL,
VMON1);
static SENSOR_DEVICE_ATTR(in1_label, S_IRUGO, powr1220_show_label, NULL,
VMON2);
static SENSOR_DEVICE_ATTR(in2_label, S_IRUGO, powr1220_show_label, NULL,
VMON3);
static SENSOR_DEVICE_ATTR(in3_label, S_IRUGO, powr1220_show_label, NULL,
VMON4);
static SENSOR_DEVICE_ATTR(in4_label, S_IRUGO, powr1220_show_label, NULL,
VMON5);
static SENSOR_DEVICE_ATTR(in5_label, S_IRUGO, powr1220_show_label, NULL,
VMON6);
static SENSOR_DEVICE_ATTR(in6_label, S_IRUGO, powr1220_show_label, NULL,
VMON7);
static SENSOR_DEVICE_ATTR(in7_label, S_IRUGO, powr1220_show_label, NULL,
VMON8);
static SENSOR_DEVICE_ATTR(in8_label, S_IRUGO, powr1220_show_label, NULL,
VMON9);
static SENSOR_DEVICE_ATTR(in9_label, S_IRUGO, powr1220_show_label, NULL,
VMON10);
static SENSOR_DEVICE_ATTR(in10_label, S_IRUGO, powr1220_show_label, NULL,
VMON11);
static SENSOR_DEVICE_ATTR(in11_label, S_IRUGO, powr1220_show_label, NULL,
VMON12);
static SENSOR_DEVICE_ATTR(in12_label, S_IRUGO, powr1220_show_label, NULL,
VCCA);
static SENSOR_DEVICE_ATTR(in13_label, S_IRUGO, powr1220_show_label, NULL,
VCCINP);
static struct attribute *powr1220_attrs[] = {
&sensor_dev_attr_in0_input.dev_attr.attr,
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_in2_input.dev_attr.attr,
&sensor_dev_attr_in3_input.dev_attr.attr,
&sensor_dev_attr_in4_input.dev_attr.attr,
&sensor_dev_attr_in5_input.dev_attr.attr,
&sensor_dev_attr_in6_input.dev_attr.attr,
&sensor_dev_attr_in7_input.dev_attr.attr,
&sensor_dev_attr_in8_input.dev_attr.attr,
&sensor_dev_attr_in9_input.dev_attr.attr,
&sensor_dev_attr_in10_input.dev_attr.attr,
&sensor_dev_attr_in11_input.dev_attr.attr,
&sensor_dev_attr_in12_input.dev_attr.attr,
&sensor_dev_attr_in13_input.dev_attr.attr,
&sensor_dev_attr_in0_highest.dev_attr.attr,
&sensor_dev_attr_in1_highest.dev_attr.attr,
&sensor_dev_attr_in2_highest.dev_attr.attr,
&sensor_dev_attr_in3_highest.dev_attr.attr,
&sensor_dev_attr_in4_highest.dev_attr.attr,
&sensor_dev_attr_in5_highest.dev_attr.attr,
&sensor_dev_attr_in6_highest.dev_attr.attr,
&sensor_dev_attr_in7_highest.dev_attr.attr,
&sensor_dev_attr_in8_highest.dev_attr.attr,
&sensor_dev_attr_in9_highest.dev_attr.attr,
&sensor_dev_attr_in10_highest.dev_attr.attr,
&sensor_dev_attr_in11_highest.dev_attr.attr,
&sensor_dev_attr_in12_highest.dev_attr.attr,
&sensor_dev_attr_in13_highest.dev_attr.attr,
&sensor_dev_attr_in0_label.dev_attr.attr,
&sensor_dev_attr_in1_label.dev_attr.attr,
&sensor_dev_attr_in2_label.dev_attr.attr,
&sensor_dev_attr_in3_label.dev_attr.attr,
&sensor_dev_attr_in4_label.dev_attr.attr,
&sensor_dev_attr_in5_label.dev_attr.attr,
&sensor_dev_attr_in6_label.dev_attr.attr,
&sensor_dev_attr_in7_label.dev_attr.attr,
&sensor_dev_attr_in8_label.dev_attr.attr,
&sensor_dev_attr_in9_label.dev_attr.attr,
&sensor_dev_attr_in10_label.dev_attr.attr,
&sensor_dev_attr_in11_label.dev_attr.attr,
&sensor_dev_attr_in12_label.dev_attr.attr,
&sensor_dev_attr_in13_label.dev_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(powr1220);
static int powr1220_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct powr1220_data *data;
struct device *hwmon_dev;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
mutex_init(&data->update_lock);
data->client = client;
hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
client->name, data, powr1220_groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id powr1220_ids[] = {
{ "powr1220", 0, },
{ }
};
MODULE_DEVICE_TABLE(i2c, powr1220_ids);
static struct i2c_driver powr1220_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "powr1220",
},
.probe = powr1220_probe,
.id_table = powr1220_ids,
};
module_i2c_driver(powr1220_driver);
MODULE_AUTHOR("Scott Kanowitz");
MODULE_DESCRIPTION("POWR1220 driver");
MODULE_LICENSE("GPL");