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Commit 2ffb500d authored by Enric Balletbo i Serra's avatar Enric Balletbo i Serra Committed by Sebastian Reichel
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power: supply: cros: allow to set input voltage and current limit 



This patch allows reading and writing the input voltage and current
limit through the POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT and
POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT sysfs properties. This allows
userspace to see current values and to re-configure these values at
runtime based on system-level knowledge or user input.

By default there is no limit, this is reported as a -1 when reading from
userspace. Writing a value will set the current or voltage limit in uA
or uV, and writing any negative value will remove that limit.

Signed-off-by: default avatarEnric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: default avatarGuenter Roeck <groeck@chromium.org>
Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent a4496d52

drivers/power/supply/cros_usbpd-charger.c

+116 −0
Original line number Diff line number Diff line
@@ -53,6 +53,8 @@ struct charger_data { 
};



static enum power_supply_property cros_usbpd_charger_props[] = {

	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,

	POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT,

	POWER_SUPPLY_PROP_ONLINE,

	POWER_SUPPLY_PROP_STATUS,

	POWER_SUPPLY_PROP_CURRENT_MAX,
@@ -80,6 +82,10 @@ static enum power_supply_usb_type cros_usbpd_charger_usb_types[] = { 
	POWER_SUPPLY_USB_TYPE_APPLE_BRICK_ID

};



/* Input voltage/current limit in mV/mA. Default to none. */

static u16 input_voltage_limit = EC_POWER_LIMIT_NONE;

static u16 input_current_limit = EC_POWER_LIMIT_NONE;



static bool cros_usbpd_charger_port_is_dedicated(struct port_data *port)

{

	return port->port_number >= port->charger->num_usbpd_ports;
@@ -324,6 +330,26 @@ static int cros_usbpd_charger_get_port_status(struct port_data *port, 
	return ret;

}



static int cros_usbpd_charger_set_ext_power_limit(struct charger_data *charger,

						  u16 current_lim,

						  u16 voltage_lim)

{

	struct ec_params_external_power_limit_v1 req;

	int ret;



	req.current_lim = current_lim;

	req.voltage_lim = voltage_lim;



	ret = cros_usbpd_charger_ec_command(charger, 0,

					    EC_CMD_EXTERNAL_POWER_LIMIT,

					    &req, sizeof(req), NULL, 0);

	if (ret < 0)

		dev_err(charger->dev,

			"Unable to set the 'External Power Limit': %d\n", ret);



	return ret;

}



static void cros_usbpd_charger_power_changed(struct power_supply *psy)

{

	struct port_data *port = power_supply_get_drvdata(psy);
@@ -396,6 +422,18 @@ static int cros_usbpd_charger_get_prop(struct power_supply *psy, 
	case POWER_SUPPLY_PROP_USB_TYPE:

		val->intval = port->psy_usb_type;

		break;

	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

		if (input_current_limit == EC_POWER_LIMIT_NONE)

			val->intval = -1;

		else

			val->intval = input_current_limit * 1000;

		break;

	case POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT:

		if (input_voltage_limit == EC_POWER_LIMIT_NONE)

			val->intval = -1;

		else

			val->intval = input_voltage_limit * 1000;

		break;

	case POWER_SUPPLY_PROP_MODEL_NAME:

		val->strval = port->model_name;

		break;
@@ -409,6 +447,81 @@ static int cros_usbpd_charger_get_prop(struct power_supply *psy, 
	return 0;

}



static int cros_usbpd_charger_set_prop(struct power_supply *psy,

				       enum power_supply_property psp,

				       const union power_supply_propval *val)

{

	struct port_data *port = power_supply_get_drvdata(psy);

	struct charger_data *charger = port->charger;

	struct device *dev = charger->dev;

	u16 intval;

	int ret;



	/* U16_MAX in mV/mA is the maximum supported value */

	if (val->intval >= U16_MAX * 1000)

		return -EINVAL;

	/* A negative number is used to clear the limit */

	if (val->intval < 0)

		intval = EC_POWER_LIMIT_NONE;

	else	/* Convert from uA/uV to mA/mV */

		intval = val->intval / 1000;



	switch (psp) {

	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

		ret = cros_usbpd_charger_set_ext_power_limit(charger, intval,

							input_voltage_limit);

		if (ret < 0)

			break;



		input_current_limit = intval;

		if (input_current_limit == EC_POWER_LIMIT_NONE)

			dev_info(dev,

			  "External Current Limit cleared for all ports\n");

		else

			dev_info(dev,

			  "External Current Limit set to %dmA for all ports\n",

			  input_current_limit);

		break;

	case POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT:

		ret = cros_usbpd_charger_set_ext_power_limit(charger,

							input_current_limit,

							intval);

		if (ret < 0)

			break;



		input_voltage_limit = intval;

		if (input_voltage_limit == EC_POWER_LIMIT_NONE)

			dev_info(dev,

			  "External Voltage Limit cleared for all ports\n");

		else

			dev_info(dev,

			  "External Voltage Limit set to %dmV for all ports\n",

			  input_voltage_limit);

		break;

	default:

		ret = -EINVAL;

	}



	return ret;

}



static int cros_usbpd_charger_property_is_writeable(struct power_supply *psy,

						enum power_supply_property psp)

{

	int ret;



	switch (psp) {

	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

	case POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT:

		ret = 1;

		break;

	default:

		ret = 0;

	}



	return ret;

}



static int cros_usbpd_charger_ec_event(struct notifier_block *nb,

				       unsigned long queued_during_suspend,

				       void *_notify)
@@ -525,6 +638,9 @@ static int cros_usbpd_charger_probe(struct platform_device *pd) 


		psy_desc = &port->psy_desc;

		psy_desc->get_property = cros_usbpd_charger_get_prop;

		psy_desc->set_property = cros_usbpd_charger_set_prop;

		psy_desc->property_is_writeable =

				cros_usbpd_charger_property_is_writeable;

		psy_desc->external_power_changed =

					cros_usbpd_charger_power_changed;

		psy_cfg.drv_data = port;