[deliverable/linux.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[8] = {
	128, 250, 490, 920, 1600, 2400, 3300, 3300 };

#define ADS1015_DEFAULT_CHANNELS 0xff
#define ADS1015_DEFAULT_PGA 2
#define ADS1015_DEFAULT_DATA_RATE 4

struct ads1015_data {
	struct device *hwmon_dev;
	struct mutex update_lock; /* mutex protect updates */
	struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
};

static s32 ads1015_read_reg(struct i2c_client *client, unsigned int reg)
{
	s32 data = i2c_smbus_read_word_data(client, reg);

	return (data < 0) ? data : swab16(data);
}

static s32 ads1015_write_reg(struct i2c_client *client, unsigned int reg,
			     u16 val)
{
	return i2c_smbus_write_word_data(client, reg, swab16(val));
}

static int ads1015_read_value(struct i2c_client *client, unsigned int channel,
			      int *value)
{
	u16 config;
	s16 conversion;
	struct ads1015_data *data = i2c_get_clientdata(client);
	unsigned int pga = data->channel_data[channel].pga;
	int fullscale;
	unsigned int data_rate = data->channel_data[channel].data_rate;
	unsigned int conversion_time_ms;
	int res;

	mutex_lock(&data->update_lock);

	/* get channel parameters */
	res = ads1015_read_reg(client, ADS1015_CONFIG);
	if (res < 0)
		goto err_unlock;
	config = res;
	fullscale = fullscale_table[pga];
	conversion_time_ms = DIV_ROUND_UP(1000, data_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 = ads1015_write_reg(client, ADS1015_CONFIG, config);
	if (res < 0)
		goto err_unlock;

	/* wait until conversion finished */
	msleep(conversion_time_ms);
	res = ads1015_read_reg(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 = ads1015_read_reg(client, ADS1015_CONVERSION);
	if (res < 0)
		goto err_unlock;
	conversion = res;

	mutex_unlock(&data->update_lock);

	*value = DIV_ROUND_CLOSEST(conversion * fullscale, 0x7ff0);

	return 0;

err_unlock:
	mutex_unlock(&data->update_lock);
	return res;
}

/* 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 in;
	int res;

	res = ads1015_read_value(client, attr->index, &in);

	return (res < 0) ? res : sprintf(buf, "%d\n", in);
}

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);
	kfree(data);
	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 = kzalloc(sizeof(struct ads1015_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto exit;
	}

	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_free;
	}

	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);
exit_free:
	kfree(data);
exit:
	return err;
}

static const struct i2c_device_id ads1015_id[] = {
	{ "ads1015", 0 },
	{ }
};
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,
};

static int __init sensors_ads1015_init(void)
{
	return i2c_add_driver(&ads1015_driver);
}

static void __exit sensors_ads1015_exit(void)
{
	i2c_del_driver(&ads1015_driver);
}

MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
MODULE_DESCRIPTION("ADS1015 driver");
MODULE_LICENSE("GPL");

module_init(sensors_ads1015_init);
module_exit(sensors_ads1015_exit);
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 DE	48	/* Data rates in samples per second */
	49	static const unsigned int data_rate_table[8] = {
	50	128, 250, 490, 920, 1600, 2400, 3300, 3300 };
	51
8c22a8f5	52	#define ADS1015_DEFAULT_CHANNELS 0xff
c0046867 DE	53	#define ADS1015_DEFAULT_PGA 2
c0046867 DE	54	#define ADS1015_DEFAULT_DATA_RATE 4
8c22a8f5 DE	55
	56	struct ads1015_data {
	57	struct device *hwmon_dev;
	58	struct mutex update_lock; /* mutex protect updates */
c0046867	59	struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
8c22a8f5 DE	60	};
	61
	62	static s32 ads1015_read_reg(struct i2c_client *client, unsigned int reg)
	63	{
	64	s32 data = i2c_smbus_read_word_data(client, reg);
	65
	66	return (data < 0) ? data : swab16(data);
	67	}
	68
	69	static s32 ads1015_write_reg(struct i2c_client *client, unsigned int reg,
	70	u16 val)
	71	{
	72	return i2c_smbus_write_word_data(client, reg, swab16(val));
	73	}
	74
	75	static int ads1015_read_value(struct i2c_client *client, unsigned int channel,
	76	int *value)
	77	{
	78	u16 config;
	79	s16 conversion;
8c22a8f5	80	struct ads1015_data *data = i2c_get_clientdata(client);
c0046867 DE	81	unsigned int pga = data->channel_data[channel].pga;
	82	int fullscale;
	83	unsigned int data_rate = data->channel_data[channel].data_rate;
	84	unsigned int conversion_time_ms;
8c22a8f5 DE	85	int res;
	86
	87	mutex_lock(&data->update_lock);
	88
c0046867	89	/* get channel parameters */
8c22a8f5 DE	90	res = ads1015_read_reg(client, ADS1015_CONFIG);
	91	if (res < 0)
	92	goto err_unlock;
	93	config = res;
8c22a8f5	94	fullscale = fullscale_table[pga];
c0046867	95	conversion_time_ms = DIV_ROUND_UP(1000, data_rate_table[data_rate]);
8c22a8f5	96
c0046867 DE	97	/* setup and start single conversion */
	98	config &= 0x001f;
	99	config \|= (1 << 15) \| (1 << 8);
	100	config \|= (channel & 0x0007) << 12;
	101	config \|= (pga & 0x0007) << 9;
	102	config \|= (data_rate & 0x0007) << 5;
8c22a8f5	103
8c22a8f5 DE	104	res = ads1015_write_reg(client, ADS1015_CONFIG, config);
	105	if (res < 0)
	106	goto err_unlock;
c0046867 DE	107
	108	/* wait until conversion finished */
	109	msleep(conversion_time_ms);
	110	res = ads1015_read_reg(client, ADS1015_CONFIG);
	111	if (res < 0)
	112	goto err_unlock;
	113	config = res;
	114	if (!(config & (1 << 15))) {
	115	/* conversion not finished in time */
8c22a8f5 DE	116	res = -EIO;
	117	goto err_unlock;
	118	}
	119
	120	res = ads1015_read_reg(client, ADS1015_CONVERSION);
	121	if (res < 0)
	122	goto err_unlock;
	123	conversion = res;
	124
	125	mutex_unlock(&data->update_lock);
	126
	127	value = DIV_ROUND_CLOSEST(conversion fullscale, 0x7ff0);
	128
	129	return 0;
	130
	131	err_unlock:
	132	mutex_unlock(&data->update_lock);
	133	return res;
	134	}
	135
	136	/* sysfs callback function */
	137	static ssize_t show_in(struct device dev, struct device_attribute da,
	138	char *buf)
	139	{
	140	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	141	struct i2c_client *client = to_i2c_client(dev);
	142	int in;
	143	int res;
	144
	145	res = ads1015_read_value(client, attr->index, &in);
	146
	147	return (res < 0) ? res : sprintf(buf, "%d\n", in);
	148	}
	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	kfree(data);
	174	return 0;
	175	}
	176
8c22a8f5	177	#ifdef CONFIG_OF
c0046867 DE	178	static int ads1015_get_channels_config_of(struct i2c_client *client)
	179	{
	180	struct ads1015_data *data = i2c_get_clientdata(client);
	181	struct device_node *node;
	182
	183	if (!client->dev.of_node
	184	\|\| !of_get_next_child(client->dev.of_node, NULL))
	185	return -EINVAL;
	186
	187	for_each_child_of_node(client->dev.of_node, node) {
	188	const __be32 *property;
	189	int len;
	190	unsigned int channel;
	191	unsigned int pga = ADS1015_DEFAULT_PGA;
	192	unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
	193
	194	property = of_get_property(node, "reg", &len);
	195	if (!property \|\| len != sizeof(int)) {
	196	dev_err(&client->dev, "invalid reg on %s\n",
	197	node->full_name);
	198	continue;
	199	}
	200
	201	channel = be32_to_cpup(property);
	202	if (channel > ADS1015_CHANNELS) {
	203	dev_err(&client->dev,
	204	"invalid channel index %d on %s\n",
	205	channel, node->full_name);
	206	continue;
	207	}
	208
	209	property = of_get_property(node, "ti,gain", &len);
	210	if (property && len == sizeof(int)) {
	211	pga = be32_to_cpup(property);
	212	if (pga > 6) {
	213	dev_err(&client->dev,
	214	"invalid gain on %s\n",
	215	node->full_name);
	216	}
	217	}
	218
	219	property = of_get_property(node, "ti,datarate", &len);
	220	if (property && len == sizeof(int)) {
	221	data_rate = be32_to_cpup(property);
	222	if (data_rate > 7) {
	223	dev_err(&client->dev,
	224	"invalid data_rate on %s\n",
	225	node->full_name);
	226	}
	227	}
	228
	229	data->channel_data[channel].enabled = true;
	230	data->channel_data[channel].pga = pga;
	231	data->channel_data[channel].data_rate = data_rate;
	232	}
	233
	234	return 0;
	235	}
8c22a8f5 DE	236	#endif
8c22a8f5 DE	237
c0046867 DE	238	static void ads1015_get_channels_config(struct i2c_client *client)
	239	{
	240	unsigned int k;
	241	struct ads1015_data *data = i2c_get_clientdata(client);
	242	struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
	243
8c22a8f5	244	/* prefer platform data */
c0046867 DE	245	if (pdata) {
	246	memcpy(data->channel_data, pdata->channel_data,
	247	sizeof(data->channel_data));
	248	return;
	249	}
8c22a8f5 DE	250
8c22a8f5 DE	251	#ifdef CONFIG_OF
c0046867 DE	252	if (!ads1015_get_channels_config_of(client))
c0046867 DE	253	return;
8c22a8f5 DE	254	#endif
	255
	256	/* fallback on default configuration */
c0046867 DE	257	for (k = 0; k < ADS1015_CHANNELS; ++k) {
	258	data->channel_data[k].enabled = true;
	259	data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
	260	data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
	261	}
8c22a8f5 DE	262	}
	263
	264	static int ads1015_probe(struct i2c_client *client,
	265	const struct i2c_device_id *id)
	266	{
	267	struct ads1015_data *data;
	268	int err;
8c22a8f5	269	unsigned int k;
8c22a8f5 DE	270
	271	data = kzalloc(sizeof(struct ads1015_data), GFP_KERNEL);
	272	if (!data) {
	273	err = -ENOMEM;
	274	goto exit;
	275	}
	276
	277	i2c_set_clientdata(client, data);
	278	mutex_init(&data->update_lock);
	279
	280	/* build sysfs attribute group */
c0046867 DE	281	ads1015_get_channels_config(client);
	282	for (k = 0; k < ADS1015_CHANNELS; ++k) {
	283	if (!data->channel_data[k].enabled)
8c22a8f5	284	continue;
fdf241a8 JD	285	err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
	286	if (err)
	287	goto exit_free;
8c22a8f5	288	}
8c22a8f5 DE	289
	290	data->hwmon_dev = hwmon_device_register(&client->dev);
	291	if (IS_ERR(data->hwmon_dev)) {
	292	err = PTR_ERR(data->hwmon_dev);
	293	goto exit_remove;
	294	}
	295
	296	return 0;
	297
	298	exit_remove:
c0046867	299	for (k = 0; k < ADS1015_CHANNELS; ++k)
fdf241a8	300	device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
8c22a8f5 DE	301	exit_free:
	302	kfree(data);
	303	exit:
	304	return err;
	305	}
	306
	307	static const struct i2c_device_id ads1015_id[] = {
	308	{ "ads1015", 0 },
	309	{ }
	310	};
	311	MODULE_DEVICE_TABLE(i2c, ads1015_id);
	312
	313	static struct i2c_driver ads1015_driver = {
	314	.driver = {
	315	.name = "ads1015",
	316	},
	317	.probe = ads1015_probe,
	318	.remove = ads1015_remove,
	319	.id_table = ads1015_id,
	320	};
	321
	322	static int __init sensors_ads1015_init(void)
	323	{
	324	return i2c_add_driver(&ads1015_driver);
	325	}
	326
	327	static void __exit sensors_ads1015_exit(void)
	328	{
	329	i2c_del_driver(&ads1015_driver);
	330	}
	331
	332	MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
	333	MODULE_DESCRIPTION("ADS1015 driver");
	334	MODULE_LICENSE("GPL");
	335
	336	module_init(sensors_ads1015_init);
	337	module_exit(sensors_ads1015_exit);