[linux-2.6-block.git] / drivers / hwmon / ads1015.c

/*
 * 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) {
		const __be32 *property;
		int len;
		unsigned int channel;
		unsigned int pga = ADS1015_DEFAULT_PGA;
		unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;

		property = of_get_property(node, "reg", &len);
		if (!property || len != sizeof(int)) {
			dev_err(&client->dev, "invalid reg on %s\n",
				node->full_name);
			continue;
		}

		channel = be32_to_cpup(property);
		if (channel >= ADS1015_CHANNELS) {
			dev_err(&client->dev,
				"invalid channel index %d on %s\n",
				channel, node->full_name);
			continue;
		}

		property = of_get_property(node, "ti,gain", &len);
		if (property && len == sizeof(int)) {
			pga = be32_to_cpup(property);
			if (pga > 6) {
				dev_err(&client->dev,
					"invalid gain on %s\n",
					node->full_name);
			}
		}

		property = of_get_property(node, "ti,datarate", &len);
		if (property && len == sizeof(int)) {
			data_rate = be32_to_cpup(property);
			if (data_rate > 7) {
				dev_err(&client->dev,
					"invalid data_rate on %s\n",
					node->full_name);
			}
		}

		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");
Commit	Line	Data
8c22a8f5 DE	1	/*
	2	* ads1015.c - lm_sensors driver for ads1015 12-bit 4-input ADC
	3	* (C) Copyright 2010
	4	* Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
	5	*
	6	* Based on the ads7828 driver by Steve Hardy.
	7	*
	8	* Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads1015.pdf
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2 of the License, or
	13	* (at your option) any later version.
	14	*
	15	* This program is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	* GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with this program; if not, write to the Free Software
	22	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	23	*/
	24
	25	#include <linux/module.h>
	26	#include <linux/init.h>
	27	#include <linux/slab.h>
	28	#include <linux/delay.h>
	29	#include <linux/i2c.h>
	30	#include <linux/hwmon.h>
	31	#include <linux/hwmon-sysfs.h>
	32	#include <linux/err.h>
	33	#include <linux/mutex.h>
	34	#include <linux/of.h>
	35
	36	#include <linux/i2c/ads1015.h>
	37
	38	/* ADS1015 registers */
	39	enum {
	40	ADS1015_CONVERSION = 0,
	41	ADS1015_CONFIG = 1,
	42	};
	43
	44	/* PGA fullscale voltages in mV */
	45	static const unsigned int fullscale_table[8] = {
	46	6144, 4096, 2048, 1024, 512, 256, 256, 256 };
	47
c0046867	48	/* Data rates in samples per second */
60c1f31f ED	49	static const unsigned int data_rate_table_1015[8] = {
	50	128, 250, 490, 920, 1600, 2400, 3300, 3300
	51	};
	52
	53	static const unsigned int data_rate_table_1115[8] = {
	54	8, 16, 32, 64, 128, 250, 475, 860
	55	};
c0046867	56
8c22a8f5	57	#define ADS1015_DEFAULT_CHANNELS 0xff
c0046867 DE	58	#define ADS1015_DEFAULT_PGA 2
c0046867 DE	59	#define ADS1015_DEFAULT_DATA_RATE 4
8c22a8f5	60
60c1f31f ED	61	enum ads1015_chips {
	62	ads1015,
	63	ads1115,
	64	};
	65
8c22a8f5 DE	66	struct ads1015_data {
	67	struct device *hwmon_dev;
	68	struct mutex update_lock; /* mutex protect updates */
c0046867	69	struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
60c1f31f	70	enum ads1015_chips id;
8c22a8f5 DE	71	};
8c22a8f5 DE	72
1196573f	73	static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
8c22a8f5 DE	74	{
8c22a8f5 DE	75	u16 config;
8c22a8f5	76	struct ads1015_data *data = i2c_get_clientdata(client);
c0046867	77	unsigned int pga = data->channel_data[channel].pga;
c0046867 DE	78	unsigned int data_rate = data->channel_data[channel].data_rate;
c0046867 DE	79	unsigned int conversion_time_ms;
60c1f31f ED	80	const unsigned int * const rate_table = data->id == ads1115 ?
60c1f31f ED	81	data_rate_table_1115 : data_rate_table_1015;
8c22a8f5 DE	82	int res;
	83
	84	mutex_lock(&data->update_lock);
	85
c0046867	86	/* get channel parameters */
90f4102c	87	res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
8c22a8f5 DE	88	if (res < 0)
	89	goto err_unlock;
	90	config = res;
60c1f31f	91	conversion_time_ms = DIV_ROUND_UP(1000, rate_table[data_rate]);
8c22a8f5	92
c0046867 DE	93	/* setup and start single conversion */
	94	config &= 0x001f;
	95	config \|= (1 << 15) \| (1 << 8);
	96	config \|= (channel & 0x0007) << 12;
	97	config \|= (pga & 0x0007) << 9;
	98	config \|= (data_rate & 0x0007) << 5;
8c22a8f5	99
90f4102c	100	res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config);
8c22a8f5 DE	101	if (res < 0)
8c22a8f5 DE	102	goto err_unlock;
c0046867 DE	103
	104	/* wait until conversion finished */
	105	msleep(conversion_time_ms);
90f4102c	106	res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
c0046867 DE	107	if (res < 0)
	108	goto err_unlock;
	109	config = res;
	110	if (!(config & (1 << 15))) {
	111	/* conversion not finished in time */
8c22a8f5 DE	112	res = -EIO;
	113	goto err_unlock;
	114	}
	115
90f4102c	116	res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
8c22a8f5 DE	117
	118	err_unlock:
	119	mutex_unlock(&data->update_lock);
	120	return res;
	121	}
	122
1196573f GR	123	static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel,
	124	s16 reg)
	125	{
	126	struct ads1015_data *data = i2c_get_clientdata(client);
	127	unsigned int pga = data->channel_data[channel].pga;
	128	int fullscale = fullscale_table[pga];
60c1f31f	129	const unsigned mask = data->id == ads1115 ? 0x7fff : 0x7ff0;
1196573f	130
60c1f31f	131	return DIV_ROUND_CLOSEST(reg * fullscale, mask);
1196573f GR	132	}
1196573f GR	133
8c22a8f5 DE	134	/* sysfs callback function */
	135	static ssize_t show_in(struct device dev, struct device_attribute da,
	136	char *buf)
	137	{
	138	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	139	struct i2c_client *client = to_i2c_client(dev);
8c22a8f5	140	int res;
1196573f	141	int index = attr->index;
8c22a8f5	142
1196573f GR	143	res = ads1015_read_adc(client, index);
	144	if (res < 0)
	145	return res;
8c22a8f5	146
1196573f	147	return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res));
8c22a8f5 DE	148	}
8c22a8f5 DE	149
fdf241a8 JD	150	static const struct sensor_device_attribute ads1015_in[] = {
	151	SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0),
	152	SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1),
	153	SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2),
	154	SENSOR_ATTR(in3_input, S_IRUGO, show_in, NULL, 3),
	155	SENSOR_ATTR(in4_input, S_IRUGO, show_in, NULL, 4),
	156	SENSOR_ATTR(in5_input, S_IRUGO, show_in, NULL, 5),
	157	SENSOR_ATTR(in6_input, S_IRUGO, show_in, NULL, 6),
	158	SENSOR_ATTR(in7_input, S_IRUGO, show_in, NULL, 7),
8c22a8f5 DE	159	};
	160
	161	/*
	162	* Driver interface
	163	*/
	164
	165	static int ads1015_remove(struct i2c_client *client)
	166	{
	167	struct ads1015_data *data = i2c_get_clientdata(client);
fdf241a8 JD	168	int k;
fdf241a8 JD	169
8c22a8f5	170	hwmon_device_unregister(data->hwmon_dev);
c0046867	171	for (k = 0; k < ADS1015_CHANNELS; ++k)
fdf241a8	172	device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
8c22a8f5 DE	173	return 0;
	174	}
	175
8c22a8f5	176	#ifdef CONFIG_OF
c0046867 DE	177	static int ads1015_get_channels_config_of(struct i2c_client *client)
	178	{
	179	struct ads1015_data *data = i2c_get_clientdata(client);
	180	struct device_node *node;
	181
	182	if (!client->dev.of_node
	183	\|\| !of_get_next_child(client->dev.of_node, NULL))
	184	return -EINVAL;
	185
	186	for_each_child_of_node(client->dev.of_node, node) {
	187	const __be32 *property;
	188	int len;
	189	unsigned int channel;
	190	unsigned int pga = ADS1015_DEFAULT_PGA;
	191	unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
	192
	193	property = of_get_property(node, "reg", &len);
	194	if (!property \|\| len != sizeof(int)) {
	195	dev_err(&client->dev, "invalid reg on %s\n",
	196	node->full_name);
	197	continue;
	198	}
	199
	200	channel = be32_to_cpup(property);
56de1377	201	if (channel >= ADS1015_CHANNELS) {
c0046867 DE	202	dev_err(&client->dev,
	203	"invalid channel index %d on %s\n",
	204	channel, node->full_name);
	205	continue;
	206	}
	207
	208	property = of_get_property(node, "ti,gain", &len);
	209	if (property && len == sizeof(int)) {
	210	pga = be32_to_cpup(property);
	211	if (pga > 6) {
	212	dev_err(&client->dev,
	213	"invalid gain on %s\n",
	214	node->full_name);
	215	}
	216	}
	217
	218	property = of_get_property(node, "ti,datarate", &len);
	219	if (property && len == sizeof(int)) {
	220	data_rate = be32_to_cpup(property);
	221	if (data_rate > 7) {
	222	dev_err(&client->dev,
	223	"invalid data_rate on %s\n",
	224	node->full_name);
	225	}
	226	}
	227
	228	data->channel_data[channel].enabled = true;
	229	data->channel_data[channel].pga = pga;
	230	data->channel_data[channel].data_rate = data_rate;
	231	}
	232
	233	return 0;
	234	}
8c22a8f5 DE	235	#endif
8c22a8f5 DE	236
c0046867 DE	237	static void ads1015_get_channels_config(struct i2c_client *client)
	238	{
	239	unsigned int k;
	240	struct ads1015_data *data = i2c_get_clientdata(client);
	241	struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
	242
8c22a8f5	243	/* prefer platform data */
c0046867 DE	244	if (pdata) {
	245	memcpy(data->channel_data, pdata->channel_data,
	246	sizeof(data->channel_data));
	247	return;
	248	}
8c22a8f5 DE	249
8c22a8f5 DE	250	#ifdef CONFIG_OF
c0046867 DE	251	if (!ads1015_get_channels_config_of(client))
c0046867 DE	252	return;
8c22a8f5 DE	253	#endif
	254
	255	/* fallback on default configuration */
c0046867 DE	256	for (k = 0; k < ADS1015_CHANNELS; ++k) {
	257	data->channel_data[k].enabled = true;
	258	data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
	259	data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
	260	}
8c22a8f5 DE	261	}
	262
	263	static int ads1015_probe(struct i2c_client *client,
	264	const struct i2c_device_id *id)
	265	{
	266	struct ads1015_data *data;
	267	int err;
8c22a8f5	268	unsigned int k;
8c22a8f5	269
57457e31 GR	270	data = devm_kzalloc(&client->dev, sizeof(struct ads1015_data),
	271	GFP_KERNEL);
	272	if (!data)
	273	return -ENOMEM;
60c1f31f	274	data->id = id->driver_data;
8c22a8f5 DE	275	i2c_set_clientdata(client, data);
	276	mutex_init(&data->update_lock);
	277
	278	/* build sysfs attribute group */
c0046867 DE	279	ads1015_get_channels_config(client);
	280	for (k = 0; k < ADS1015_CHANNELS; ++k) {
	281	if (!data->channel_data[k].enabled)
8c22a8f5	282	continue;
fdf241a8 JD	283	err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
fdf241a8 JD	284	if (err)
363434b5	285	goto exit_remove;
8c22a8f5	286	}
8c22a8f5 DE	287
	288	data->hwmon_dev = hwmon_device_register(&client->dev);
	289	if (IS_ERR(data->hwmon_dev)) {
	290	err = PTR_ERR(data->hwmon_dev);
	291	goto exit_remove;
	292	}
	293
	294	return 0;
	295
	296	exit_remove:
c0046867	297	for (k = 0; k < ADS1015_CHANNELS; ++k)
fdf241a8	298	device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
8c22a8f5 DE	299	return err;
	300	}
	301
	302	static const struct i2c_device_id ads1015_id[] = {
60c1f31f ED	303	{ "ads1015", ads1015},
60c1f31f ED	304	{ "ads1115", ads1115},
8c22a8f5 DE	305	{ }
	306	};
	307	MODULE_DEVICE_TABLE(i2c, ads1015_id);
	308
	309	static struct i2c_driver ads1015_driver = {
	310	.driver = {
	311	.name = "ads1015",
	312	},
	313	.probe = ads1015_probe,
	314	.remove = ads1015_remove,
	315	.id_table = ads1015_id,
	316	};
	317
f0967eea	318	module_i2c_driver(ads1015_driver);
8c22a8f5 DE	319
	320	MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
	321	MODULE_DESCRIPTION("ADS1015 driver");
	322	MODULE_LICENSE("GPL");