On Thu, Nov 22, 2018 at 2:11 AM Enric Balletbo i Serra <enric.balle...@collabora.com> wrote: > > 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 <enric.balle...@collabora.com>
Reviewed-by: Guenter Roeck <gro...@chromium.org> > --- > > Changes in v2: > - Fix the upper limit that can be set. > - Remove unnecessary else. > > 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 7e9c3984ef6a..3a9ea94c3de3 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; > -- > 2.19.1 >