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

/*
 * System Control and Power Interface(SCPI) based hwmon sensor driver
 *
 * Copyright (C) 2015 ARM Ltd.
 * Punit Agrawal <punit.agrawal@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/scpi_protocol.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>

struct sensor_data {
	struct scpi_sensor_info info;
	struct device_attribute dev_attr_input;
	struct device_attribute dev_attr_label;
	char input[20];
	char label[20];
};

struct scpi_thermal_zone {
	struct list_head list;
	int sensor_id;
	struct scpi_sensors *scpi_sensors;
	struct thermal_zone_device *tzd;
};

struct scpi_sensors {
	struct scpi_ops *scpi_ops;
	struct sensor_data *data;
	struct list_head thermal_zones;
	struct attribute **attrs;
	struct attribute_group group;
	const struct attribute_group *groups[2];
};

static int scpi_read_temp(void *dev, int *temp)
{
	struct scpi_thermal_zone *zone = dev;
	struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
	struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
	u32 value;
	int ret;

	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
	if (ret)
		return ret;

	*temp = value;
	return 0;
}

/* hwmon callback functions */
static ssize_t
scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev);
	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
	struct sensor_data *sensor;
	u32 value;
	int ret;

	sensor = container_of(attr, struct sensor_data, dev_attr_input);

	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
	if (ret)
		return ret;

	return sprintf(buf, "%u\n", value);
}

static ssize_t
scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct sensor_data *sensor;

	sensor = container_of(attr, struct sensor_data, dev_attr_label);

	return sprintf(buf, "%s\n", sensor->info.name);
}

static void
unregister_thermal_zones(struct platform_device *pdev,
			 struct scpi_sensors *scpi_sensors)
{
	struct list_head *pos;

	list_for_each(pos, &scpi_sensors->thermal_zones) {
		struct scpi_thermal_zone *zone;

		zone = list_entry(pos, struct scpi_thermal_zone, list);
		thermal_zone_of_sensor_unregister(&pdev->dev, zone->tzd);
	}
}

static struct thermal_zone_of_device_ops scpi_sensor_ops = {
	.get_temp = scpi_read_temp,
};

static int scpi_hwmon_probe(struct platform_device *pdev)
{
	u16 nr_sensors, i;
	int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
	struct scpi_ops *scpi_ops;
	struct device *hwdev, *dev = &pdev->dev;
	struct scpi_sensors *scpi_sensors;
	int ret;

	scpi_ops = get_scpi_ops();
	if (!scpi_ops)
		return -EPROBE_DEFER;

	ret = scpi_ops->sensor_get_capability(&nr_sensors);
	if (ret)
		return ret;

	if (!nr_sensors)
		return -ENODEV;

	scpi_sensors = devm_kzalloc(dev, sizeof(*scpi_sensors), GFP_KERNEL);
	if (!scpi_sensors)
		return -ENOMEM;

	scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
				   sizeof(*scpi_sensors->data), GFP_KERNEL);
	if (!scpi_sensors->data)
		return -ENOMEM;

	scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
				   sizeof(*scpi_sensors->attrs), GFP_KERNEL);
	if (!scpi_sensors->attrs)
		return -ENOMEM;

	scpi_sensors->scpi_ops = scpi_ops;

	for (i = 0; i < nr_sensors; i++) {
		struct sensor_data *sensor = &scpi_sensors->data[i];

		ret = scpi_ops->sensor_get_info(i, &sensor->info);
		if (ret)
			return ret;

		switch (sensor->info.class) {
		case TEMPERATURE:
			snprintf(sensor->input, sizeof(sensor->input),
				 "temp%d_input", num_temp + 1);
			snprintf(sensor->label, sizeof(sensor->input),
				 "temp%d_label", num_temp + 1);
			num_temp++;
			break;
		case VOLTAGE:
			snprintf(sensor->input, sizeof(sensor->input),
				 "in%d_input", num_volt);
			snprintf(sensor->label, sizeof(sensor->input),
				 "in%d_label", num_volt);
			num_volt++;
			break;
		case CURRENT:
			snprintf(sensor->input, sizeof(sensor->input),
				 "curr%d_input", num_current + 1);
			snprintf(sensor->label, sizeof(sensor->input),
				 "curr%d_label", num_current + 1);
			num_current++;
			break;
		case POWER:
			snprintf(sensor->input, sizeof(sensor->input),
				 "power%d_input", num_power + 1);
			snprintf(sensor->label, sizeof(sensor->input),
				 "power%d_label", num_power + 1);
			num_power++;
			break;
		default:
			break;
		}

		sensor->dev_attr_input.attr.mode = S_IRUGO;
		sensor->dev_attr_input.show = scpi_show_sensor;
		sensor->dev_attr_input.attr.name = sensor->input;

		sensor->dev_attr_label.attr.mode = S_IRUGO;
		sensor->dev_attr_label.show = scpi_show_label;
		sensor->dev_attr_label.attr.name = sensor->label;

		scpi_sensors->attrs[i << 1] = &sensor->dev_attr_input.attr;
		scpi_sensors->attrs[(i << 1) + 1] = &sensor->dev_attr_label.attr;

		sysfs_attr_init(scpi_sensors->attrs[i << 1]);
		sysfs_attr_init(scpi_sensors->attrs[(i << 1) + 1]);
	}

	scpi_sensors->group.attrs = scpi_sensors->attrs;
	scpi_sensors->groups[0] = &scpi_sensors->group;

	platform_set_drvdata(pdev, scpi_sensors);

	hwdev = devm_hwmon_device_register_with_groups(dev,
			"scpi_sensors", scpi_sensors, scpi_sensors->groups);

	if (IS_ERR(hwdev))
		return PTR_ERR(hwdev);

	/*
	 * Register the temperature sensors with the thermal framework
	 * to allow their usage in setting up the thermal zones from
	 * device tree.
	 *
	 * NOTE: Not all temperature sensors maybe used for thermal
	 * control
	 */
	INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
	for (i = 0; i < nr_sensors; i++) {
		struct sensor_data *sensor = &scpi_sensors->data[i];
		struct scpi_thermal_zone *zone;

		if (sensor->info.class != TEMPERATURE)
			continue;

		zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
		if (!zone) {
			ret = -ENOMEM;
			goto unregister_tzd;
		}

		zone->sensor_id = i;
		zone->scpi_sensors = scpi_sensors;
		zone->tzd = thermal_zone_of_sensor_register(dev, i, zone,
							    &scpi_sensor_ops);
		/*
		 * The call to thermal_zone_of_sensor_register returns
		 * an error for sensors that are not associated with
		 * any thermal zones or if the thermal subsystem is
		 * not configured.
		 */
		if (IS_ERR(zone->tzd)) {
			devm_kfree(dev, zone);
			continue;
		}
		list_add(&zone->list, &scpi_sensors->thermal_zones);
	}

	return 0;

unregister_tzd:
	unregister_thermal_zones(pdev, scpi_sensors);
	return ret;
}

static int scpi_hwmon_remove(struct platform_device *pdev)
{
	struct scpi_sensors *scpi_sensors = platform_get_drvdata(pdev);

	unregister_thermal_zones(pdev, scpi_sensors);

	return 0;
}

static const struct of_device_id scpi_of_match[] = {
	{.compatible = "arm,scpi-sensors"},
	{},
};

static struct platform_driver scpi_hwmon_platdrv = {
	.driver = {
		.name	= "scpi-hwmon",
		.owner	= THIS_MODULE,
		.of_match_table = scpi_of_match,
	},
	.probe		= scpi_hwmon_probe,
	.remove		= scpi_hwmon_remove,
};
module_platform_driver(scpi_hwmon_platdrv);

MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
ea98b29a PA	1	/*
	2	* System Control and Power Interface(SCPI) based hwmon sensor driver
	3	*
	4	* Copyright (C) 2015 ARM Ltd.
	5	* Punit Agrawal <punit.agrawal@arm.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	12	* kind, whether express or implied; without even the implied warranty
	13	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*/
	16
	17	#include <linux/hwmon.h>
	18	#include <linux/module.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/scpi_protocol.h>
	21	#include <linux/slab.h>
	22	#include <linux/sysfs.h>
68acc77a	23	#include <linux/thermal.h>
ea98b29a PA	24
	25	struct sensor_data {
	26	struct scpi_sensor_info info;
	27	struct device_attribute dev_attr_input;
	28	struct device_attribute dev_attr_label;
	29	char input[20];
	30	char label[20];
	31	};
	32
68acc77a PA	33	struct scpi_thermal_zone {
	34	struct list_head list;
	35	int sensor_id;
	36	struct scpi_sensors *scpi_sensors;
	37	struct thermal_zone_device *tzd;
	38	};
	39
ea98b29a PA	40	struct scpi_sensors {
	41	struct scpi_ops *scpi_ops;
	42	struct sensor_data *data;
68acc77a	43	struct list_head thermal_zones;
ea98b29a PA	44	struct attribute **attrs;
	45	struct attribute_group group;
	46	const struct attribute_group *groups[2];
	47	};
	48
68acc77a PA	49	static int scpi_read_temp(void dev, int temp)
	50	{
	51	struct scpi_thermal_zone *zone = dev;
	52	struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
	53	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
	54	struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
	55	u32 value;
	56	int ret;
	57
	58	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
	59	if (ret)
	60	return ret;
	61
	62	*temp = value;
	63	return 0;
	64	}
	65
ea98b29a PA	66	/* hwmon callback functions */
	67	static ssize_t
	68	scpi_show_sensor(struct device dev, struct device_attribute attr, char *buf)
	69	{
	70	struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev);
	71	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
	72	struct sensor_data *sensor;
	73	u32 value;
	74	int ret;
	75
	76	sensor = container_of(attr, struct sensor_data, dev_attr_input);
	77
	78	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
	79	if (ret)
	80	return ret;
	81
	82	return sprintf(buf, "%u\n", value);
	83	}
	84
	85	static ssize_t
	86	scpi_show_label(struct device dev, struct device_attribute attr, char *buf)
	87	{
	88	struct sensor_data *sensor;
	89
	90	sensor = container_of(attr, struct sensor_data, dev_attr_label);
	91
	92	return sprintf(buf, "%s\n", sensor->info.name);
	93	}
	94
68acc77a PA	95	static void
	96	unregister_thermal_zones(struct platform_device *pdev,
	97	struct scpi_sensors *scpi_sensors)
	98	{
	99	struct list_head *pos;
	100
	101	list_for_each(pos, &scpi_sensors->thermal_zones) {
	102	struct scpi_thermal_zone *zone;
	103
	104	zone = list_entry(pos, struct scpi_thermal_zone, list);
	105	thermal_zone_of_sensor_unregister(&pdev->dev, zone->tzd);
	106	}
	107	}
	108
	109	static struct thermal_zone_of_device_ops scpi_sensor_ops = {
	110	.get_temp = scpi_read_temp,
	111	};
	112
ea98b29a PA	113	static int scpi_hwmon_probe(struct platform_device *pdev)
	114	{
	115	u16 nr_sensors, i;
	116	int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
	117	struct scpi_ops *scpi_ops;
	118	struct device hwdev, dev = &pdev->dev;
	119	struct scpi_sensors *scpi_sensors;
	120	int ret;
	121
	122	scpi_ops = get_scpi_ops();
	123	if (!scpi_ops)
	124	return -EPROBE_DEFER;
	125
	126	ret = scpi_ops->sensor_get_capability(&nr_sensors);
	127	if (ret)
	128	return ret;
	129
	130	if (!nr_sensors)
	131	return -ENODEV;
	132
	133	scpi_sensors = devm_kzalloc(dev, sizeof(*scpi_sensors), GFP_KERNEL);
	134	if (!scpi_sensors)
	135	return -ENOMEM;
	136
	137	scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
	138	sizeof(*scpi_sensors->data), GFP_KERNEL);
	139	if (!scpi_sensors->data)
	140	return -ENOMEM;
	141
	142	scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
	143	sizeof(*scpi_sensors->attrs), GFP_KERNEL);
	144	if (!scpi_sensors->attrs)
	145	return -ENOMEM;
	146
	147	scpi_sensors->scpi_ops = scpi_ops;
	148
	149	for (i = 0; i < nr_sensors; i++) {
	150	struct sensor_data *sensor = &scpi_sensors->data[i];
	151
	152	ret = scpi_ops->sensor_get_info(i, &sensor->info);
	153	if (ret)
	154	return ret;
	155
	156	switch (sensor->info.class) {
	157	case TEMPERATURE:
	158	snprintf(sensor->input, sizeof(sensor->input),
	159	"temp%d_input", num_temp + 1);
	160	snprintf(sensor->label, sizeof(sensor->input),
	161	"temp%d_label", num_temp + 1);
	162	num_temp++;
	163	break;
	164	case VOLTAGE:
	165	snprintf(sensor->input, sizeof(sensor->input),
	166	"in%d_input", num_volt);
	167	snprintf(sensor->label, sizeof(sensor->input),
	168	"in%d_label", num_volt);
	169	num_volt++;
	170	break;
	171	case CURRENT:
	172	snprintf(sensor->input, sizeof(sensor->input),
	173	"curr%d_input", num_current + 1);
	174	snprintf(sensor->label, sizeof(sensor->input),
	175	"curr%d_label", num_current + 1);
	176	num_current++;
177	break;
178	case POWER:
179	snprintf(sensor->input, sizeof(sensor->input),
180	"power%d_input", num_power + 1);
181	snprintf(sensor->label, sizeof(sensor->input),
182	"power%d_label", num_power + 1);
183	num_power++;
184	break;
185	default:
186	break;
187	}
188
189	sensor->dev_attr_input.attr.mode = S_IRUGO;
190	sensor->dev_attr_input.show = scpi_show_sensor;
191	sensor->dev_attr_input.attr.name = sensor->input;
192
193	sensor->dev_attr_label.attr.mode = S_IRUGO;
194	sensor->dev_attr_label.show = scpi_show_label;
195	sensor->dev_attr_label.attr.name = sensor->label;
196
197	scpi_sensors->attrs[i << 1] = &sensor->dev_attr_input.attr;
198	scpi_sensors->attrs[(i << 1) + 1] = &sensor->dev_attr_label.attr;
199
200	sysfs_attr_init(scpi_sensors->attrs[i << 1]);
201	sysfs_attr_init(scpi_sensors->attrs[(i << 1) + 1]);
202	}
203
204	scpi_sensors->group.attrs = scpi_sensors->attrs;
205	scpi_sensors->groups[0] = &scpi_sensors->group;
206
68acc77a PA	207	platform_set_drvdata(pdev, scpi_sensors);
68acc77a PA	208
ea98b29a PA	209	hwdev = devm_hwmon_device_register_with_groups(dev,
	210	"scpi_sensors", scpi_sensors, scpi_sensors->groups);
	211
68acc77a PA	212	if (IS_ERR(hwdev))
	213	return PTR_ERR(hwdev);
	214
	215	/*
	216	* Register the temperature sensors with the thermal framework
	217	* to allow their usage in setting up the thermal zones from
	218	* device tree.
	219	*
	220	* NOTE: Not all temperature sensors maybe used for thermal
	221	* control
	222	*/
	223	INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
	224	for (i = 0; i < nr_sensors; i++) {
	225	struct sensor_data *sensor = &scpi_sensors->data[i];
	226	struct scpi_thermal_zone *zone;
	227
	228	if (sensor->info.class != TEMPERATURE)
	229	continue;
	230
	231	zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
	232	if (!zone) {
	233	ret = -ENOMEM;
	234	goto unregister_tzd;
	235	}
	236
	237	zone->sensor_id = i;
	238	zone->scpi_sensors = scpi_sensors;
	239	zone->tzd = thermal_zone_of_sensor_register(dev, i, zone,
	240	&scpi_sensor_ops);
	241	/*
	242	* The call to thermal_zone_of_sensor_register returns
	243	* an error for sensors that are not associated with
	244	* any thermal zones or if the thermal subsystem is
	245	* not configured.
	246	*/
	247	if (IS_ERR(zone->tzd)) {
	248	devm_kfree(dev, zone);
	249	continue;
	250	}
	251	list_add(&zone->list, &scpi_sensors->thermal_zones);
	252	}
	253
	254	return 0;
	255
	256	unregister_tzd:
	257	unregister_thermal_zones(pdev, scpi_sensors);
	258	return ret;
	259	}
	260
	261	static int scpi_hwmon_remove(struct platform_device *pdev)
	262	{
	263	struct scpi_sensors *scpi_sensors = platform_get_drvdata(pdev);
	264
	265	unregister_thermal_zones(pdev, scpi_sensors);
	266
	267	return 0;
ea98b29a PA	268	}
	269
	270	static const struct of_device_id scpi_of_match[] = {
	271	{.compatible = "arm,scpi-sensors"},
	272	{},
	273	};
	274
	275	static struct platform_driver scpi_hwmon_platdrv = {
	276	.driver = {
	277	.name = "scpi-hwmon",
	278	.owner = THIS_MODULE,
	279	.of_match_table = scpi_of_match,
	280	},
	281	.probe = scpi_hwmon_probe,
68acc77a	282	.remove = scpi_hwmon_remove,
ea98b29a PA	283	};
	284	module_platform_driver(scpi_hwmon_platdrv);
	285
	286	MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
	287	MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
	288	MODULE_LICENSE("GPL v2");