--- /dev/null
+/*
+ * 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.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 unsigned 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;
+ 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 struct i2c_driver ads1015_driver = {
+ .driver = {
+ .name = "ads1015",
+ },
+ .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");
Code Review / kvmfornfv.git / blobdiff