drivers/hwmon/ads1015.c - linux - Git at Google

 /*
  * 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/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");
	/*
	* 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/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");