swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 4fe89d07dcc2804c8b562f6c7896a45643d34b2f authored by Linus Torvalds on 02 October 2022, 21:09:07 UTC
Linux 6.0
Linux 6.0
Tip revision: 4fe89d0
powr1220.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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 https://www.echo360.com
* Scott Kanowitz <skanowitz@echo360.com> <scott.kanowitz@gmail.com>
*/
#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 powr1xxx_chips { powr1014, powr1220 };
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;
u8 max_channels;
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;
}
static umode_t
powr1220_is_visible(const void *data, enum hwmon_sensor_types type, u32
attr, int channel)
{
struct powr1220_data *chip_data = (struct powr1220_data *)data;
if (channel >= chip_data->max_channels)
return 0;
switch (type) {
case hwmon_in:
switch (attr) {
case hwmon_in_input:
case hwmon_in_highest:
case hwmon_in_label:
return 0444;
default:
break;
}
break;
default:
break;
}
return 0;
}
static int
powr1220_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
int channel, const char **str)
{
switch (type) {
case hwmon_in:
switch (attr) {
case hwmon_in_label:
*str = input_names[channel];
return 0;
default:
return -EOPNOTSUPP;
}
break;
default:
return -EOPNOTSUPP;
}
return -EOPNOTSUPP;
}
static int
powr1220_read(struct device *dev, enum hwmon_sensor_types type, u32
attr, int channel, long *val)
{
struct powr1220_data *data = dev_get_drvdata(dev);
int ret;
switch (type) {
case hwmon_in:
switch (attr) {
case hwmon_in_input:
ret = powr1220_read_adc(dev, channel);
if (ret < 0)
return ret;
*val = ret;
break;
case hwmon_in_highest:
*val = data->adc_maxes[channel];
break;
default:
return -EOPNOTSUPP;
}
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static const struct hwmon_channel_info *powr1220_info[] = {
HWMON_CHANNEL_INFO(in,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_HIGHEST | HWMON_I_LABEL),
NULL
};
static const struct hwmon_ops powr1220_hwmon_ops = {
.read = powr1220_read,
.read_string = powr1220_read_string,
.is_visible = powr1220_is_visible,
};
static const struct hwmon_chip_info powr1220_chip_info = {
.ops = &powr1220_hwmon_ops,
.info = powr1220_info,
};
static const struct i2c_device_id powr1220_ids[];
static int powr1220_probe(struct i2c_client *client)
{
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;
switch (i2c_match_id(powr1220_ids, client)->driver_data) {
case powr1014:
data->max_channels = 10;
break;
default:
data->max_channels = 12;
break;
}
mutex_init(&data->update_lock);
data->client = client;
hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
client->name,
data,
&powr1220_chip_info,
NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id powr1220_ids[] = {
{ "powr1014", powr1014, },
{ "powr1220", powr1220, },
{ }
};
MODULE_DEVICE_TABLE(i2c, powr1220_ids);
static struct i2c_driver powr1220_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "powr1220",
},
.probe_new = powr1220_probe,
.id_table = powr1220_ids,
};
module_i2c_driver(powr1220_driver);
MODULE_AUTHOR("Scott Kanowitz");
MODULE_DESCRIPTION("POWR1220 driver");
MODULE_LICENSE("GPL");