| /* |
| * 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 |
| * |
| * 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. |
| */ |
| |
| #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/i2c/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 show_in(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(in0_input, S_IRUGO, show_in, NULL, 0), |
| SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1), |
| SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2), |
| SENSOR_ATTR(in3_input, S_IRUGO, show_in, NULL, 3), |
| SENSOR_ATTR(in4_input, S_IRUGO, show_in, NULL, 4), |
| SENSOR_ATTR(in5_input, S_IRUGO, show_in, NULL, 5), |
| SENSOR_ATTR(in6_input, S_IRUGO, show_in, NULL, 6), |
| SENSOR_ATTR(in7_input, S_IRUGO, show_in, NULL, 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 %s\n", |
| node->full_name); |
| continue; |
| } |
| |
| channel = pval; |
| if (channel >= ADS1015_CHANNELS) { |
| dev_err(&client->dev, |
| "invalid channel index %d on %s\n", |
| channel, node->full_name); |
| continue; |
| } |
| |
| if (!of_property_read_u32(node, "ti,gain", &pval)) { |
| pga = pval; |
| if (pga > 6) { |
| dev_err(&client->dev, "invalid gain on %s\n", |
| node->full_name); |
| 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 %s\n", |
| node->full_name); |
| 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 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"); |