+++ /dev/null
-Kernel driver ads1015
-=====================
-
-Supported chips:
-
- * Texas Instruments ADS1015
-
- Prefix: 'ads1015'
-
- Datasheet: Publicly available at the Texas Instruments website:
-
- http://focus.ti.com/lit/ds/symlink/ads1015.pdf
-
- * Texas Instruments ADS1115
-
- Prefix: 'ads1115'
-
- Datasheet: Publicly available at the Texas Instruments website:
-
- http://focus.ti.com/lit/ds/symlink/ads1115.pdf
-
-Authors:
- Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
-
-Description
------------
-
-This driver implements support for the Texas Instruments ADS1015/ADS1115.
-
-This device is a 12/16-bit A-D converter with 4 inputs.
-
-The inputs can be used single ended or in certain differential combinations.
-
-The inputs can be made available by 8 sysfs input files in0_input - in7_input:
-
- - in0: Voltage over AIN0 and AIN1.
- - in1: Voltage over AIN0 and AIN3.
- - in2: Voltage over AIN1 and AIN3.
- - in3: Voltage over AIN2 and AIN3.
- - in4: Voltage over AIN0 and GND.
- - in5: Voltage over AIN1 and GND.
- - in6: Voltage over AIN2 and GND.
- - in7: Voltage over AIN3 and GND.
-
-Which inputs are available can be configured using platform data or devicetree.
-
-By default all inputs are exported.
-
-Platform Data
--------------
-
-In linux/platform_data/ads1015.h platform data is defined, channel_data contains
-configuration data for the used input combinations:
-
-- pga is the programmable gain amplifier (values are full scale)
-
- - 0: +/- 6.144 V
- - 1: +/- 4.096 V
- - 2: +/- 2.048 V
- - 3: +/- 1.024 V
- - 4: +/- 0.512 V
- - 5: +/- 0.256 V
-
-- data_rate in samples per second
-
- - 0: 128
- - 1: 250
- - 2: 490
- - 3: 920
- - 4: 1600
- - 5: 2400
- - 6: 3300
-
-Example::
-
- struct ads1015_platform_data data = {
- .channel_data = {
- [2] = { .enabled = true, .pga = 1, .data_rate = 0 },
- [4] = { .enabled = true, .pga = 4, .data_rate = 5 },
- }
- };
-
-In this case only in2_input (FS +/- 4.096 V, 128 SPS) and in4_input
-(FS +/- 0.512 V, 2400 SPS) would be created.
-
-Devicetree
-----------
-
-Configuration is also possible via devicetree:
-Documentation/devicetree/bindings/hwmon/ads1015.txt
+++ /dev/null
-// 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");
projects / openwrt / staging / blogic.git / commitdiff