From 2ffb500d824bbe6535c64d3e7e9971cca0db0a3e Mon Sep 17 00:00:00 2001 From: Enric Balletbo i Serra Date: Tue, 7 May 2019 11:52:48 +0200 Subject: [PATCH] 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: Enric Balletbo i Serra Reviewed-by: Guenter Roeck Signed-off-by: Sebastian Reichel --- drivers/power/supply/cros_usbpd-charger.c | 116 ++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) diff --git a/drivers/power/supply/cros_usbpd-charger.c b/drivers/power/supply/cros_usbpd-charger.c index 7e9c398..3a9ea94 100644 --- a/drivers/power/supply/cros_usbpd-charger.c +++ b/drivers/power/supply/cros_usbpd-charger.c @@ -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; -- 2.7.4