[patch 17/32] greybus: power supply driver

[Greg KH]

This driver implements the Greybus power supply class protocol.

Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/greybus/power_supply.c | 1141 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1141 insertions(+)

--- /dev/null
+++ b/drivers/greybus/power_supply.c
@@ -0,0 +1,1141 @@
+/*
+ * Power Supply driver for a Greybus module.
+ *
+ * Copyright 2014-2015 Google Inc.
+ * Copyright 2014-2015 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+
+#include "greybus.h"
+
+#define PROP_MAX 32
+
+struct gb_power_supply_prop {
+	enum power_supply_property	prop;
+	u8				gb_prop;
+	int				val;
+	int				previous_val;
+	bool				is_writeable;
+};
+
+struct gb_power_supply {
+	u8				id;
+	bool				registered;
+	struct power_supply		*psy;
+	struct power_supply_desc	desc;
+	char				name[64];
+	struct gb_power_supplies	*supplies;
+	struct delayed_work		work;
+	char				*manufacturer;
+	char				*model_name;
+	char				*serial_number;
+	u8				type;
+	u8				properties_count;
+	u8				properties_count_str;
+	unsigned long			last_update;
+	u8				cache_invalid;
+	unsigned int			update_interval;
+	bool				changed;
+	struct gb_power_supply_prop	*props;
+	enum power_supply_property	*props_raw;
+	bool				pm_acquired;
+	struct mutex			supply_lock;
+};
+
+struct gb_power_supplies {
+	struct gb_connection	*connection;
+	u8			supplies_count;
+	struct gb_power_supply	*supply;
+	struct mutex		supplies_lock;
+};
+
+#define to_gb_power_supply(x) power_supply_get_drvdata(x)
+
+/*
+ * General power supply properties that could be absent from various reasons,
+ * like kernel versions or vendor specific versions
+ */
+#ifndef POWER_SUPPLY_PROP_VOLTAGE_BOOT
+	#define POWER_SUPPLY_PROP_VOLTAGE_BOOT	-1
+#endif
+#ifndef POWER_SUPPLY_PROP_CURRENT_BOOT
+	#define POWER_SUPPLY_PROP_CURRENT_BOOT	-1
+#endif
+#ifndef POWER_SUPPLY_PROP_CALIBRATE
+	#define POWER_SUPPLY_PROP_CALIBRATE	-1
+#endif
+
+/* cache time in milliseconds, if cache_time is set to 0 cache is disable */
+static unsigned int cache_time = 1000;
+/*
+ * update interval initial and maximum value, between the two will
+ * back-off exponential
+ */
+static unsigned int update_interval_init = 1 * HZ;
+static unsigned int update_interval_max = 30 * HZ;
+
+struct gb_power_supply_changes {
+	enum power_supply_property	prop;
+	u32				tolerance_change;
+	void (*prop_changed)(struct gb_power_supply *gbpsy,
+			     struct gb_power_supply_prop *prop);
+};
+
+static void gb_power_supply_state_change(struct gb_power_supply *gbpsy,
+					 struct gb_power_supply_prop *prop);
+
+static const struct gb_power_supply_changes psy_props_changes[] = {
+	{	.prop			= GB_POWER_SUPPLY_PROP_STATUS,
+		.tolerance_change	= 0,
+		.prop_changed		= gb_power_supply_state_change,
+	},
+	{	.prop			= GB_POWER_SUPPLY_PROP_TEMP,
+		.tolerance_change	= 500,
+		.prop_changed		= NULL,
+	},
+	{	.prop			= GB_POWER_SUPPLY_PROP_ONLINE,
+		.tolerance_change	= 0,
+		.prop_changed		= NULL,
+	},
+};
+
+static int get_psp_from_gb_prop(int gb_prop, enum power_supply_property *psp)
+{
+	int prop;
+
+	switch (gb_prop) {
+	case GB_POWER_SUPPLY_PROP_STATUS:
+		prop = POWER_SUPPLY_PROP_STATUS;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_TYPE:
+		prop = POWER_SUPPLY_PROP_CHARGE_TYPE;
+		break;
+	case GB_POWER_SUPPLY_PROP_HEALTH:
+		prop = POWER_SUPPLY_PROP_HEALTH;
+		break;
+	case GB_POWER_SUPPLY_PROP_PRESENT:
+		prop = POWER_SUPPLY_PROP_PRESENT;
+		break;
+	case GB_POWER_SUPPLY_PROP_ONLINE:
+		prop = POWER_SUPPLY_PROP_ONLINE;
+		break;
+	case GB_POWER_SUPPLY_PROP_AUTHENTIC:
+		prop = POWER_SUPPLY_PROP_AUTHENTIC;
+		break;
+	case GB_POWER_SUPPLY_PROP_TECHNOLOGY:
+		prop = POWER_SUPPLY_PROP_TECHNOLOGY;
+		break;
+	case GB_POWER_SUPPLY_PROP_CYCLE_COUNT:
+		prop = POWER_SUPPLY_PROP_CYCLE_COUNT;
+		break;
+	case GB_POWER_SUPPLY_PROP_VOLTAGE_MAX:
+		prop = POWER_SUPPLY_PROP_VOLTAGE_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_VOLTAGE_MIN:
+		prop = POWER_SUPPLY_PROP_VOLTAGE_MIN;
+		break;
+	case GB_POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		prop = POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN;
+		break;
+	case GB_POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		prop = POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN;
+		break;
+	case GB_POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		prop = POWER_SUPPLY_PROP_VOLTAGE_NOW;
+		break;
+	case GB_POWER_SUPPLY_PROP_VOLTAGE_AVG:
+		prop = POWER_SUPPLY_PROP_VOLTAGE_AVG;
+		break;
+	case GB_POWER_SUPPLY_PROP_VOLTAGE_OCV:
+		prop = POWER_SUPPLY_PROP_VOLTAGE_OCV;
+		break;
+	case GB_POWER_SUPPLY_PROP_VOLTAGE_BOOT:
+		prop = POWER_SUPPLY_PROP_VOLTAGE_BOOT;
+		break;
+	case GB_POWER_SUPPLY_PROP_CURRENT_MAX:
+		prop = POWER_SUPPLY_PROP_CURRENT_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_CURRENT_NOW:
+		prop = POWER_SUPPLY_PROP_CURRENT_NOW;
+		break;
+	case GB_POWER_SUPPLY_PROP_CURRENT_AVG:
+		prop = POWER_SUPPLY_PROP_CURRENT_AVG;
+		break;
+	case GB_POWER_SUPPLY_PROP_CURRENT_BOOT:
+		prop = POWER_SUPPLY_PROP_CURRENT_BOOT;
+		break;
+	case GB_POWER_SUPPLY_PROP_POWER_NOW:
+		prop = POWER_SUPPLY_PROP_POWER_NOW;
+		break;
+	case GB_POWER_SUPPLY_PROP_POWER_AVG:
+		prop = POWER_SUPPLY_PROP_POWER_AVG;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+		prop = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
+		prop = POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_FULL:
+		prop = POWER_SUPPLY_PROP_CHARGE_FULL;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_EMPTY:
+		prop = POWER_SUPPLY_PROP_CHARGE_EMPTY;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_NOW:
+		prop = POWER_SUPPLY_PROP_CHARGE_NOW;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_AVG:
+		prop = POWER_SUPPLY_PROP_CHARGE_AVG;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_COUNTER:
+		prop = POWER_SUPPLY_PROP_CHARGE_COUNTER;
+		break;
+	case GB_POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		prop = POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT;
+		break;
+	case GB_POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+		prop = POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		prop = POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE;
+		break;
+	case GB_POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		prop = POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+		prop = POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		prop = POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		prop = POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT;
+		break;
+	case GB_POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
+		prop = POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN;
+		break;
+	case GB_POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN:
+		prop = POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN;
+		break;
+	case GB_POWER_SUPPLY_PROP_ENERGY_FULL:
+		prop = POWER_SUPPLY_PROP_ENERGY_FULL;
+		break;
+	case GB_POWER_SUPPLY_PROP_ENERGY_EMPTY:
+		prop = POWER_SUPPLY_PROP_ENERGY_EMPTY;
+		break;
+	case GB_POWER_SUPPLY_PROP_ENERGY_NOW:
+		prop = POWER_SUPPLY_PROP_ENERGY_NOW;
+		break;
+	case GB_POWER_SUPPLY_PROP_ENERGY_AVG:
+		prop = POWER_SUPPLY_PROP_ENERGY_AVG;
+		break;
+	case GB_POWER_SUPPLY_PROP_CAPACITY:
+		prop = POWER_SUPPLY_PROP_CAPACITY;
+		break;
+	case GB_POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
+		prop = POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN;
+		break;
+	case GB_POWER_SUPPLY_PROP_CAPACITY_ALERT_MAX:
+		prop = POWER_SUPPLY_PROP_CAPACITY_ALERT_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_CAPACITY_LEVEL:
+		prop = POWER_SUPPLY_PROP_CAPACITY_LEVEL;
+		break;
+	case GB_POWER_SUPPLY_PROP_TEMP:
+		prop = POWER_SUPPLY_PROP_TEMP;
+		break;
+	case GB_POWER_SUPPLY_PROP_TEMP_MAX:
+		prop = POWER_SUPPLY_PROP_TEMP_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_TEMP_MIN:
+		prop = POWER_SUPPLY_PROP_TEMP_MIN;
+		break;
+	case GB_POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
+		prop = POWER_SUPPLY_PROP_TEMP_ALERT_MIN;
+		break;
+	case GB_POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
+		prop = POWER_SUPPLY_PROP_TEMP_ALERT_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_TEMP_AMBIENT:
+		prop = POWER_SUPPLY_PROP_TEMP_AMBIENT;
+		break;
+	case GB_POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN:
+		prop = POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN;
+		break;
+	case GB_POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX:
+		prop = POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX;
+		break;
+	case GB_POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
+		prop = POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW;
+		break;
+	case GB_POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
+		prop = POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG;
+		break;
+	case GB_POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
+		prop = POWER_SUPPLY_PROP_TIME_TO_FULL_NOW;
+		break;
+	case GB_POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
+		prop = POWER_SUPPLY_PROP_TIME_TO_FULL_AVG;
+		break;
+	case GB_POWER_SUPPLY_PROP_TYPE:
+		prop = POWER_SUPPLY_PROP_TYPE;
+		break;
+	case GB_POWER_SUPPLY_PROP_SCOPE:
+		prop = POWER_SUPPLY_PROP_SCOPE;
+		break;
+	case GB_POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+		prop = POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT;
+		break;
+	case GB_POWER_SUPPLY_PROP_CALIBRATE:
+		prop = POWER_SUPPLY_PROP_CALIBRATE;
+		break;
+	default:
+		prop = -1;
+		break;
+	}
+
+	if (prop < 0)
+		return prop;
+
+	*psp = (enum power_supply_property)prop;
+
+	return 0;
+}
+
+static struct gb_connection *get_conn_from_psy(struct gb_power_supply *gbpsy)
+{
+	return gbpsy->supplies->connection;
+}
+
+static struct gb_power_supply_prop *get_psy_prop(struct gb_power_supply *gbpsy,
+						 enum power_supply_property psp)
+{
+	int i;
+
+	for (i = 0; i < gbpsy->properties_count; i++)
+		if (gbpsy->props[i].prop == psp)
+			return &gbpsy->props[i];
+	return NULL;
+}
+
+static int is_psy_prop_writeable(struct gb_power_supply *gbpsy,
+				     enum power_supply_property psp)
+{
+	struct gb_power_supply_prop *prop;
+
+	prop = get_psy_prop(gbpsy, psp);
+	if (!prop)
+		return -ENOENT;
+	return prop->is_writeable ? 1 : 0;
+}
+
+static int is_prop_valint(enum power_supply_property psp)
+{
+	return ((psp < POWER_SUPPLY_PROP_MODEL_NAME) ? 1 : 0);
+}
+
+static void next_interval(struct gb_power_supply *gbpsy)
+{
+	if (gbpsy->update_interval == update_interval_max)
+		return;
+
+	/* do some exponential back-off in the update interval */
+	gbpsy->update_interval *= 2;
+	if (gbpsy->update_interval > update_interval_max)
+		gbpsy->update_interval = update_interval_max;
+}
+
+static void __gb_power_supply_changed(struct gb_power_supply *gbpsy)
+{
+	power_supply_changed(gbpsy->psy);
+}
+
+static void gb_power_supply_state_change(struct gb_power_supply *gbpsy,
+					 struct gb_power_supply_prop *prop)
+{
+	struct gb_connection *connection = get_conn_from_psy(gbpsy);
+	int ret;
+
+	/*
+	 * Check gbpsy->pm_acquired to make sure only one pair of 'get_sync'
+	 * and 'put_autosuspend' runtime pm call for state property change.
+	 */
+	mutex_lock(&gbpsy->supply_lock);
+
+	if ((prop->val == GB_POWER_SUPPLY_STATUS_CHARGING) &&
+	    !gbpsy->pm_acquired) {
+		ret = gb_pm_runtime_get_sync(connection->bundle);
+		if (ret)
+			dev_err(&connection->bundle->dev,
+				"Fail to set wake lock for charging state\n");
+		else
+			gbpsy->pm_acquired = true;
+	} else {
+		if (gbpsy->pm_acquired) {
+			ret = gb_pm_runtime_put_autosuspend(connection->bundle);
+			if (ret)
+				dev_err(&connection->bundle->dev,
+					"Fail to set wake unlock for none charging\n");
+			else
+				gbpsy->pm_acquired = false;
+		}
+	}
+
+	mutex_unlock(&gbpsy->supply_lock);
+}
+
+static void check_changed(struct gb_power_supply *gbpsy,
+			  struct gb_power_supply_prop *prop)
+{
+	const struct gb_power_supply_changes *psyc;
+	int val = prop->val;
+	int prev_val = prop->previous_val;
+	bool changed = false;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(psy_props_changes); i++) {
+		psyc = &psy_props_changes[i];
+		if (prop->prop == psyc->prop) {
+			if (!psyc->tolerance_change)
+				changed = true;
+			else if (val < prev_val &&
+				 prev_val - val > psyc->tolerance_change)
+				changed = true;
+			else if (val > prev_val &&
+				 val - prev_val > psyc->tolerance_change)
+				changed = true;
+
+			if (changed && psyc->prop_changed)
+				psyc->prop_changed(gbpsy, prop);
+
+			if (changed)
+				gbpsy->changed = true;
+			break;
+		}
+	}
+}
+
+static int total_props(struct gb_power_supply *gbpsy)
+{
+	/* this return the intval plus the strval properties */
+	return (gbpsy->properties_count + gbpsy->properties_count_str);
+}
+
+static void prop_append(struct gb_power_supply *gbpsy,
+			enum power_supply_property prop)
+{
+	enum power_supply_property *new_props_raw;
+
+	gbpsy->properties_count_str++;
+	new_props_raw = krealloc(gbpsy->props_raw, total_props(gbpsy) *
+				 sizeof(enum power_supply_property),
+				 GFP_KERNEL);
+	if (!new_props_raw)
+		return;
+	gbpsy->props_raw = new_props_raw;
+	gbpsy->props_raw[total_props(gbpsy) - 1] = prop;
+}
+
+static int __gb_power_supply_set_name(char *init_name, char *name, size_t len)
+{
+	unsigned int i = 0;
+	int ret = 0;
+	struct power_supply *psy;
+
+	if (!strlen(init_name))
+		init_name = "gb_power_supply";
+	strlcpy(name, init_name, len);
+
+	while ((ret < len) && (psy = power_supply_get_by_name(name))) {
+		power_supply_put(psy);
+
+		ret = snprintf(name, len, "%s_%u", init_name, ++i);
+	}
+	if (ret >= len)
+		return -ENOMEM;
+	return i;
+}
+
+static void _gb_power_supply_append_props(struct gb_power_supply *gbpsy)
+{
+	if (strlen(gbpsy->manufacturer))
+		prop_append(gbpsy, POWER_SUPPLY_PROP_MANUFACTURER);
+	if (strlen(gbpsy->model_name))
+		prop_append(gbpsy, POWER_SUPPLY_PROP_MODEL_NAME);
+	if (strlen(gbpsy->serial_number))
+		prop_append(gbpsy, POWER_SUPPLY_PROP_SERIAL_NUMBER);
+}
+
+static int gb_power_supply_description_get(struct gb_power_supply *gbpsy)
+{
+	struct gb_connection *connection = get_conn_from_psy(gbpsy);
+	struct gb_power_supply_get_description_request req;
+	struct gb_power_supply_get_description_response resp;
+	int ret;
+
+	req.psy_id = gbpsy->id;
+
+	ret = gb_operation_sync(connection,
+				GB_POWER_SUPPLY_TYPE_GET_DESCRIPTION,
+				&req, sizeof(req), &resp, sizeof(resp));
+	if (ret < 0)
+		return ret;
+
+	gbpsy->manufacturer = kstrndup(resp.manufacturer, PROP_MAX, GFP_KERNEL);
+	if (!gbpsy->manufacturer)
+		return -ENOMEM;
+	gbpsy->model_name = kstrndup(resp.model, PROP_MAX, GFP_KERNEL);
+	if (!gbpsy->model_name)
+		return -ENOMEM;
+	gbpsy->serial_number = kstrndup(resp.serial_number, PROP_MAX,
+				       GFP_KERNEL);
+	if (!gbpsy->serial_number)
+		return -ENOMEM;
+
+	gbpsy->type = le16_to_cpu(resp.type);
+	gbpsy->properties_count = resp.properties_count;
+
+	return 0;
+}
+
+static int gb_power_supply_prop_descriptors_get(struct gb_power_supply *gbpsy)
+{
+	struct gb_connection *connection = get_conn_from_psy(gbpsy);
+	struct gb_power_supply_get_property_descriptors_request *req;
+	struct gb_power_supply_get_property_descriptors_response *resp;
+	struct gb_operation *op;
+	u8 props_count = gbpsy->properties_count;
+	enum power_supply_property psp;
+	int ret;
+	int i, r = 0;
+
+	if (props_count == 0)
+		return 0;
+
+	op = gb_operation_create(connection,
+				 GB_POWER_SUPPLY_TYPE_GET_PROP_DESCRIPTORS,
+				 sizeof(req), sizeof(*resp) + props_count *
+				 sizeof(struct gb_power_supply_props_desc),
+				 GFP_KERNEL);
+	if (!op)
+		return -ENOMEM;
+
+	req = op->request->payload;
+	req->psy_id = gbpsy->id;
+
+	ret = gb_operation_request_send_sync(op);
+	if (ret < 0)
+		goto out_put_operation;
+
+	resp = op->response->payload;
+
+	/* validate received properties */
+	for (i = 0; i < props_count; i++) {
+		ret = get_psp_from_gb_prop(resp->props[i].property, &psp);
+		if (ret < 0) {
+			dev_warn(&connection->bundle->dev,
+				 "greybus property %u it is not supported by this kernel, dropped\n",
+				 resp->props[i].property);
+			gbpsy->properties_count--;
+		}
+	}
+
+	gbpsy->props = kcalloc(gbpsy->properties_count, sizeof(*gbpsy->props),
+			      GFP_KERNEL);
+	if (!gbpsy->props) {
+		ret = -ENOMEM;
+		goto out_put_operation;
+	}
+
+	gbpsy->props_raw = kcalloc(gbpsy->properties_count,
+				   sizeof(*gbpsy->props_raw), GFP_KERNEL);
+	if (!gbpsy->props_raw) {
+		ret = -ENOMEM;
+		goto out_put_operation;
+	}
+
+	/* Store available properties, skip the ones we do not support */
+	for (i = 0; i < props_count; i++) {
+		ret = get_psp_from_gb_prop(resp->props[i].property, &psp);
+		if (ret < 0) {
+			r++;
+			continue;
+		}
+		gbpsy->props[i - r].prop = psp;
+		gbpsy->props[i - r].gb_prop = resp->props[i].property;
+		gbpsy->props_raw[i - r] = psp;
+		if (resp->props[i].is_writeable)
+			gbpsy->props[i - r].is_writeable = true;
+	}
+
+	/*
+	 * now append the properties that we already got information in the
+	 * get_description operation. (char * ones)
+	 */
+	_gb_power_supply_append_props(gbpsy);
+
+	ret = 0;
+out_put_operation:
+	gb_operation_put(op);
+
+	return ret;
+}
+
+static int __gb_power_supply_property_update(struct gb_power_supply *gbpsy,
+					     enum power_supply_property psp)
+{
+	struct gb_connection *connection = get_conn_from_psy(gbpsy);
+	struct gb_power_supply_prop *prop;
+	struct gb_power_supply_get_property_request req;
+	struct gb_power_supply_get_property_response resp;
+	int val;
+	int ret;
+
+	prop = get_psy_prop(gbpsy, psp);
+	if (!prop)
+		return -EINVAL;
+	req.psy_id = gbpsy->id;
+	req.property = prop->gb_prop;
+
+	ret = gb_operation_sync(connection, GB_POWER_SUPPLY_TYPE_GET_PROPERTY,
+				&req, sizeof(req), &resp, sizeof(resp));
+	if (ret < 0)
+		return ret;
+
+	val = le32_to_cpu(resp.prop_val);
+	if (val == prop->val)
+		return 0;
+
+	prop->previous_val = prop->val;
+	prop->val = val;
+
+	check_changed(gbpsy, prop);
+
+	return 0;
+}
+
+static int __gb_power_supply_property_get(struct gb_power_supply *gbpsy,
+					  enum power_supply_property psp,
+					  union power_supply_propval *val)
+{
+	struct gb_power_supply_prop *prop;
+
+	prop = get_psy_prop(gbpsy, psp);
+	if (!prop)
+		return -EINVAL;
+
+	val->intval = prop->val;
+	return 0;
+}
+
+static int __gb_power_supply_property_strval_get(struct gb_power_supply *gbpsy,
+						enum power_supply_property psp,
+						union power_supply_propval *val)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = gbpsy->model_name;
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = gbpsy->manufacturer;
+		break;
+	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+		val->strval = gbpsy->serial_number;
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int _gb_power_supply_property_get(struct gb_power_supply *gbpsy,
+					 enum power_supply_property psp,
+					 union power_supply_propval *val)
+{
+	struct gb_connection *connection = get_conn_from_psy(gbpsy);
+	int ret;
+
+	/*
+	 * Properties of type const char *, were already fetched on
+	 * get_description operation and should be cached in gb
+	 */
+	if (is_prop_valint(psp))
+		ret = __gb_power_supply_property_get(gbpsy, psp, val);
+	else
+		ret = __gb_power_supply_property_strval_get(gbpsy, psp, val);
+
+	if (ret < 0)
+		dev_err(&connection->bundle->dev, "get property %u\n", psp);
+
+	return 0;
+}
+
+static int is_cache_valid(struct gb_power_supply *gbpsy)
+{
+	/* check if cache is good enough or it has expired */
+	if (gbpsy->cache_invalid) {
+		gbpsy->cache_invalid = 0;
+		return 0;
+	}
+
+	if (gbpsy->last_update &&
+	    time_is_after_jiffies(gbpsy->last_update +
+				  msecs_to_jiffies(cache_time)))
+		return 1;
+
+	return 0;
+}
+
+static int gb_power_supply_status_get(struct gb_power_supply *gbpsy)
+{
+	struct gb_connection *connection = get_conn_from_psy(gbpsy);
+	int ret = 0;
+	int i;
+
+	if (is_cache_valid(gbpsy))
+		return 0;
+
+	ret = gb_pm_runtime_get_sync(connection->bundle);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < gbpsy->properties_count; i++) {
+		ret = __gb_power_supply_property_update(gbpsy,
+							gbpsy->props[i].prop);
+		if (ret < 0)
+			break;
+	}
+
+	if (ret == 0)
+		gbpsy->last_update = jiffies;
+
+	gb_pm_runtime_put_autosuspend(connection->bundle);
+	return ret;
+}
+
+static void gb_power_supply_status_update(struct gb_power_supply *gbpsy)
+{
+	/* check if there a change that need to be reported */
+	gb_power_supply_status_get(gbpsy);
+
+	if (!gbpsy->changed)
+		return;
+
+	gbpsy->update_interval = update_interval_init;
+	__gb_power_supply_changed(gbpsy);
+	gbpsy->changed = false;
+}
+
+static void gb_power_supply_work(struct work_struct *work)
+{
+	struct gb_power_supply *gbpsy = container_of(work,
+						     struct gb_power_supply,
+						     work.work);
+
+	/*
+	 * if the poll interval is not set, disable polling, this is helpful
+	 * specially at unregister time.
+	 */
+	if (!gbpsy->update_interval)
+		return;
+
+	gb_power_supply_status_update(gbpsy);
+	next_interval(gbpsy);
+	schedule_delayed_work(&gbpsy->work, gbpsy->update_interval);
+}
+
+static int get_property(struct power_supply *b,
+			enum power_supply_property psp,
+			union power_supply_propval *val)
+{
+	struct gb_power_supply *gbpsy = to_gb_power_supply(b);
+
+	gb_power_supply_status_get(gbpsy);
+
+	return _gb_power_supply_property_get(gbpsy, psp, val);
+}
+
+static int gb_power_supply_property_set(struct gb_power_supply *gbpsy,
+					enum power_supply_property psp,
+					int val)
+{
+	struct gb_connection *connection = get_conn_from_psy(gbpsy);
+	struct gb_power_supply_prop *prop;
+	struct gb_power_supply_set_property_request req;
+	int ret;
+
+	ret = gb_pm_runtime_get_sync(connection->bundle);
+	if (ret)
+		return ret;
+
+	prop = get_psy_prop(gbpsy, psp);
+	if (!prop) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	req.psy_id = gbpsy->id;
+	req.property = prop->gb_prop;
+	req.prop_val = cpu_to_le32((s32)val);
+
+	ret = gb_operation_sync(connection, GB_POWER_SUPPLY_TYPE_SET_PROPERTY,
+				&req, sizeof(req), NULL, 0);
+	if (ret < 0)
+		goto out;
+
+	/* cache immediately the new value */
+	prop->val = val;
+
+out:
+	gb_pm_runtime_put_autosuspend(connection->bundle);
+	return ret;
+}
+
+static int set_property(struct power_supply *b,
+			enum power_supply_property psp,
+			const union power_supply_propval *val)
+{
+	struct gb_power_supply *gbpsy = to_gb_power_supply(b);
+
+	return gb_power_supply_property_set(gbpsy, psp, val->intval);
+}
+
+static int property_is_writeable(struct power_supply *b,
+				 enum power_supply_property psp)
+{
+	struct gb_power_supply *gbpsy = to_gb_power_supply(b);
+
+	return is_psy_prop_writeable(gbpsy, psp);
+}
+
+static int gb_power_supply_register(struct gb_power_supply *gbpsy)
+{
+	struct gb_connection *connection = get_conn_from_psy(gbpsy);
+	struct power_supply_config cfg = {};
+
+	cfg.drv_data = gbpsy;
+
+	gbpsy->desc.name		= gbpsy->name;
+	gbpsy->desc.type		= gbpsy->type;
+	gbpsy->desc.properties		= gbpsy->props_raw;
+	gbpsy->desc.num_properties	= total_props(gbpsy);
+	gbpsy->desc.get_property	= get_property;
+	gbpsy->desc.set_property	= set_property;
+	gbpsy->desc.property_is_writeable = property_is_writeable;
+
+	gbpsy->psy = power_supply_register(&connection->bundle->dev,
+					   &gbpsy->desc, &cfg);
+	return PTR_ERR_OR_ZERO(gbpsy->psy);
+}
+
+static void _gb_power_supply_free(struct gb_power_supply *gbpsy)
+{
+	kfree(gbpsy->serial_number);
+	kfree(gbpsy->model_name);
+	kfree(gbpsy->manufacturer);
+	kfree(gbpsy->props_raw);
+	kfree(gbpsy->props);
+}
+
+static void _gb_power_supply_release(struct gb_power_supply *gbpsy)
+{
+	gbpsy->update_interval = 0;
+
+	cancel_delayed_work_sync(&gbpsy->work);
+
+	if (gbpsy->registered)
+		power_supply_unregister(gbpsy->psy);
+
+	_gb_power_supply_free(gbpsy);
+}
+
+static void _gb_power_supplies_release(struct gb_power_supplies *supplies)
+{
+	int i;
+
+	if (!supplies->supply)
+		return;
+
+	mutex_lock(&supplies->supplies_lock);
+	for (i = 0; i < supplies->supplies_count; i++)
+		_gb_power_supply_release(&supplies->supply[i]);
+	kfree(supplies->supply);
+	mutex_unlock(&supplies->supplies_lock);
+	kfree(supplies);
+}
+
+static int gb_power_supplies_get_count(struct gb_power_supplies *supplies)
+{
+	struct gb_power_supply_get_supplies_response resp;
+	int ret;
+
+	ret = gb_operation_sync(supplies->connection,
+				GB_POWER_SUPPLY_TYPE_GET_SUPPLIES,
+				NULL, 0, &resp, sizeof(resp));
+	if (ret < 0)
+		return ret;
+
+	if  (!resp.supplies_count)
+		return -EINVAL;
+
+	supplies->supplies_count = resp.supplies_count;
+
+	return ret;
+}
+
+static int gb_power_supply_config(struct gb_power_supplies *supplies, int id)
+{
+	struct gb_power_supply *gbpsy = &supplies->supply[id];
+	int ret;
+
+	gbpsy->supplies = supplies;
+	gbpsy->id = id;
+
+	ret = gb_power_supply_description_get(gbpsy);
+	if (ret < 0)
+		return ret;
+
+	return gb_power_supply_prop_descriptors_get(gbpsy);
+}
+
+static int gb_power_supply_enable(struct gb_power_supply *gbpsy)
+{
+	int ret;
+
+	/* guarantee that we have an unique name, before register */
+	ret =  __gb_power_supply_set_name(gbpsy->model_name, gbpsy->name,
+					  sizeof(gbpsy->name));
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&gbpsy->supply_lock);
+
+	ret = gb_power_supply_register(gbpsy);
+	if (ret < 0)
+		return ret;
+
+	gbpsy->update_interval = update_interval_init;
+	INIT_DELAYED_WORK(&gbpsy->work, gb_power_supply_work);
+	schedule_delayed_work(&gbpsy->work, 0);
+
+	/* everything went fine, mark it for release code to know */
+	gbpsy->registered = true;
+
+	return 0;
+}
+
+static int gb_power_supplies_setup(struct gb_power_supplies *supplies)
+{
+	struct gb_connection *connection = supplies->connection;
+	int ret;
+	int i;
+
+	mutex_lock(&supplies->supplies_lock);
+
+	ret = gb_power_supplies_get_count(supplies);
+	if (ret < 0)
+		goto out;
+
+	supplies->supply = kzalloc(supplies->supplies_count *
+				     sizeof(struct gb_power_supply),
+				     GFP_KERNEL);
+
+	if (!supplies->supply) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	for (i = 0; i < supplies->supplies_count; i++) {
+		ret = gb_power_supply_config(supplies, i);
+		if (ret < 0) {
+			dev_err(&connection->bundle->dev,
+				"Fail to configure supplies devices\n");
+			goto out;
+		}
+	}
+out:
+	mutex_unlock(&supplies->supplies_lock);
+	return ret;
+}
+
+static int gb_power_supplies_register(struct gb_power_supplies *supplies)
+{
+	struct gb_connection *connection = supplies->connection;
+	int ret = 0;
+	int i;
+
+	mutex_lock(&supplies->supplies_lock);
+
+	for (i = 0; i < supplies->supplies_count; i++) {
+		ret = gb_power_supply_enable(&supplies->supply[i]);
+		if (ret < 0) {
+			dev_err(&connection->bundle->dev,
+				"Fail to enable supplies devices\n");
+			break;
+		}
+	}
+
+	mutex_unlock(&supplies->supplies_lock);
+	return ret;
+}
+
+static int gb_supplies_request_handler(struct gb_operation *op)
+{
+	struct gb_connection *connection = op->connection;
+	struct gb_power_supplies *supplies = gb_connection_get_data(connection);
+	struct gb_power_supply *gbpsy;
+	struct gb_message *request;
+	struct gb_power_supply_event_request *payload;
+	u8 psy_id;
+	u8 event;
+	int ret = 0;
+
+	if (op->type != GB_POWER_SUPPLY_TYPE_EVENT) {
+		dev_err(&connection->bundle->dev,
+			"Unsupported unsolicited event: %u\n", op->type);
+		return -EINVAL;
+	}
+
+	request = op->request;
+
+	if (request->payload_size < sizeof(*payload)) {
+		dev_err(&connection->bundle->dev,
+			"Wrong event size received (%zu < %zu)\n",
+			request->payload_size, sizeof(*payload));
+		return -EINVAL;
+	}
+
+	payload = request->payload;
+	psy_id = payload->psy_id;
+	mutex_lock(&supplies->supplies_lock);
+	if (psy_id >= supplies->supplies_count ||
+	    !supplies->supply[psy_id].registered) {
+		dev_err(&connection->bundle->dev,
+			"Event received for unconfigured power_supply id: %d\n",
+			psy_id);
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	event = payload->event;
+	/*
+	 * we will only handle events after setup is done and before release is
+	 * running. For that just check update_interval.
+	 */
+	gbpsy = &supplies->supply[psy_id];
+	if (!gbpsy->update_interval) {
+		ret = -ESHUTDOWN;
+		goto out_unlock;
+	}
+
+	if (event & GB_POWER_SUPPLY_UPDATE) {
+		/*
+		 * we need to make sure we invalidate cache, if not no new
+		 * values for the properties will be fetch and the all propose
+		 * of this event is missed
+		 */
+		gbpsy->cache_invalid = 1;
+		gb_power_supply_status_update(gbpsy);
+	}
+
+out_unlock:
+	mutex_unlock(&supplies->supplies_lock);
+	return ret;
+}
+
+static int gb_power_supply_probe(struct gb_bundle *bundle,
+				 const struct greybus_bundle_id *id)
+{
+	struct greybus_descriptor_cport *cport_desc;
+	struct gb_connection *connection;
+	struct gb_power_supplies *supplies;
+	int ret;
+
+	if (bundle->num_cports != 1)
+		return -ENODEV;
+
+	cport_desc = &bundle->cport_desc[0];
+	if (cport_desc->protocol_id != GREYBUS_PROTOCOL_POWER_SUPPLY)
+		return -ENODEV;
+
+	supplies = kzalloc(sizeof(*supplies), GFP_KERNEL);
+	if (!supplies)
+		return -ENOMEM;
+
+	connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
+					  gb_supplies_request_handler);
+	if (IS_ERR(connection)) {
+		ret = PTR_ERR(connection);
+		goto out;
+	}
+
+	supplies->connection = connection;
+	gb_connection_set_data(connection, supplies);
+
+	mutex_init(&supplies->supplies_lock);
+
+	greybus_set_drvdata(bundle, supplies);
+
+	/* We aren't ready to receive an incoming request yet */
+	ret = gb_connection_enable_tx(connection);
+	if (ret)
+		goto error_connection_destroy;
+
+	ret = gb_power_supplies_setup(supplies);
+	if (ret < 0)
+		goto error_connection_disable;
+
+	/* We are ready to receive an incoming request now, enable RX as well */
+	ret = gb_connection_enable(connection);
+	if (ret)
+		goto error_connection_disable;
+
+	ret = gb_power_supplies_register(supplies);
+	if (ret < 0)
+		goto error_connection_disable;
+
+	gb_pm_runtime_put_autosuspend(bundle);
+	return 0;
+
+error_connection_disable:
+	gb_connection_disable(connection);
+error_connection_destroy:
+	gb_connection_destroy(connection);
+out:
+	_gb_power_supplies_release(supplies);
+	return ret;
+}
+
+static void gb_power_supply_disconnect(struct gb_bundle *bundle)
+{
+	struct gb_power_supplies *supplies = greybus_get_drvdata(bundle);
+
+	gb_connection_disable(supplies->connection);
+	gb_connection_destroy(supplies->connection);
+
+	_gb_power_supplies_release(supplies);
+}
+
+static const struct greybus_bundle_id gb_power_supply_id_table[] = {
+	{ GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_POWER_SUPPLY) },
+	{ }
+};
+MODULE_DEVICE_TABLE(greybus, gb_power_supply_id_table);
+
+static struct greybus_driver gb_power_supply_driver = {
+	.name		= "power_supply",
+	.probe		= gb_power_supply_probe,
+	.disconnect	= gb_power_supply_disconnect,
+	.id_table	= gb_power_supply_id_table,
+};
+module_greybus_driver(gb_power_supply_driver);
+
+MODULE_LICENSE("GPL v2");