Initial import

1 files changed, 319 insertions, 0 deletions

diff --git a/drivers/hwmon/ads1015.c b/drivers/hwmon/ads1015.c
new file mode 100644
index 000000000..f155b8380
--- /dev/null
+++ b/drivers/hwmon/ads1015.c
@@ -0,0 +1,319 @@
+/*
+ * 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");