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2ce8284c31
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Acked-by: David Lechner <david@lechnology.com> Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
233 lines
6.3 KiB
C
233 lines
6.3 KiB
C
/*
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* Battery driver for LEGO MINDSTORMS EV3
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*
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* Copyright (C) 2017 David Lechner <david@lechnology.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/gpio/consumer.h>
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#include <linux/iio/consumer.h>
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#include <linux/iio/types.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/platform_device.h>
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#include <linux/power_supply.h>
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struct lego_ev3_battery {
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struct iio_channel *iio_v;
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struct iio_channel *iio_i;
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struct gpio_desc *rechargeable_gpio;
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struct power_supply *psy;
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int technology;
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int v_max;
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int v_min;
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};
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static int lego_ev3_battery_get_property(struct power_supply *psy,
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enum power_supply_property psp,
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union power_supply_propval *val)
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{
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struct lego_ev3_battery *batt = power_supply_get_drvdata(psy);
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int ret, val2;
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switch (psp) {
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case POWER_SUPPLY_PROP_TECHNOLOGY:
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val->intval = batt->technology;
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break;
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case POWER_SUPPLY_PROP_VOLTAGE_NOW:
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/* battery voltage is iio channel * 2 + Vce of transistor */
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ret = iio_read_channel_processed(batt->iio_v, &val->intval);
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if (ret)
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return ret;
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val->intval *= 2000;
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val->intval += 50000;
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/* plus adjust for shunt resistor drop */
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ret = iio_read_channel_processed(batt->iio_i, &val2);
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if (ret)
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return ret;
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val2 *= 1000;
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val2 /= 15;
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val->intval += val2;
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break;
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case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
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val->intval = batt->v_max;
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break;
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case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
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val->intval = batt->v_min;
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break;
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case POWER_SUPPLY_PROP_CURRENT_NOW:
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/* battery current is iio channel / 15 / 0.05 ohms */
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ret = iio_read_channel_processed(batt->iio_i, &val->intval);
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if (ret)
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return ret;
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val->intval *= 20000;
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val->intval /= 15;
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break;
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case POWER_SUPPLY_PROP_SCOPE:
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val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static int lego_ev3_battery_set_property(struct power_supply *psy,
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enum power_supply_property psp,
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const union power_supply_propval *val)
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{
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struct lego_ev3_battery *batt = power_supply_get_drvdata(psy);
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switch (psp) {
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case POWER_SUPPLY_PROP_TECHNOLOGY:
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/*
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* Only allow changing technology from Unknown to NiMH. Li-ion
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* batteries are automatically detected and should not be
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* overridden. Rechargeable AA batteries, on the other hand,
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* cannot be automatically detected, and so must be manually
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* specified. This should only be set once during system init,
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* so there is no mechanism to go back to Unknown.
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*/
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if (batt->technology != POWER_SUPPLY_TECHNOLOGY_UNKNOWN)
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return -EINVAL;
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switch (val->intval) {
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case POWER_SUPPLY_TECHNOLOGY_NiMH:
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batt->technology = POWER_SUPPLY_TECHNOLOGY_NiMH;
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batt->v_max = 7800000;
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batt->v_min = 5400000;
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break;
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default:
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return -EINVAL;
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}
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static int lego_ev3_battery_property_is_writeable(struct power_supply *psy,
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enum power_supply_property psp)
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{
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struct lego_ev3_battery *batt = power_supply_get_drvdata(psy);
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return psp == POWER_SUPPLY_PROP_TECHNOLOGY &&
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batt->technology == POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
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}
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static enum power_supply_property lego_ev3_battery_props[] = {
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POWER_SUPPLY_PROP_TECHNOLOGY,
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POWER_SUPPLY_PROP_VOLTAGE_NOW,
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POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
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POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
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POWER_SUPPLY_PROP_CURRENT_NOW,
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POWER_SUPPLY_PROP_SCOPE,
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};
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static const struct power_supply_desc lego_ev3_battery_desc = {
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.name = "lego-ev3-battery",
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.type = POWER_SUPPLY_TYPE_BATTERY,
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.properties = lego_ev3_battery_props,
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.num_properties = ARRAY_SIZE(lego_ev3_battery_props),
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.get_property = lego_ev3_battery_get_property,
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.set_property = lego_ev3_battery_set_property,
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.property_is_writeable = lego_ev3_battery_property_is_writeable,
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};
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static int lego_ev3_battery_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct lego_ev3_battery *batt;
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struct power_supply_config psy_cfg = {};
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int err;
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batt = devm_kzalloc(dev, sizeof(*batt), GFP_KERNEL);
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if (!batt)
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return -ENOMEM;
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platform_set_drvdata(pdev, batt);
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batt->iio_v = devm_iio_channel_get(dev, "voltage");
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err = PTR_ERR_OR_ZERO(batt->iio_v);
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if (err)
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return dev_err_probe(dev, err,
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"Failed to get voltage iio channel\n");
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batt->iio_i = devm_iio_channel_get(dev, "current");
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err = PTR_ERR_OR_ZERO(batt->iio_i);
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if (err)
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return dev_err_probe(dev, err,
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"Failed to get current iio channel\n");
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batt->rechargeable_gpio = devm_gpiod_get(dev, "rechargeable", GPIOD_IN);
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err = PTR_ERR_OR_ZERO(batt->rechargeable_gpio);
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if (err)
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return dev_err_probe(dev, err,
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"Failed to get rechargeable gpio\n");
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/*
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* The rechargeable battery indication switch cannot be changed without
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* removing the battery, so we only need to read it once.
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*/
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if (gpiod_get_value(batt->rechargeable_gpio)) {
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/* 2-cell Li-ion, 7.4V nominal */
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batt->technology = POWER_SUPPLY_TECHNOLOGY_LION;
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batt->v_max = 84000000;
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batt->v_min = 60000000;
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} else {
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/* 6x AA Alkaline, 9V nominal */
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batt->technology = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
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batt->v_max = 90000000;
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batt->v_min = 48000000;
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}
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psy_cfg.of_node = pdev->dev.of_node;
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psy_cfg.drv_data = batt;
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batt->psy = devm_power_supply_register(dev, &lego_ev3_battery_desc,
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&psy_cfg);
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err = PTR_ERR_OR_ZERO(batt->psy);
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if (err) {
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dev_err(dev, "failed to register power supply\n");
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return err;
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}
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return 0;
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}
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static const struct of_device_id of_lego_ev3_battery_match[] = {
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{ .compatible = "lego,ev3-battery", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, of_lego_ev3_battery_match);
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static struct platform_driver lego_ev3_battery_driver = {
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.driver = {
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.name = "lego-ev3-battery",
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.of_match_table = of_lego_ev3_battery_match,
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},
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.probe = lego_ev3_battery_probe,
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};
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module_platform_driver(lego_ev3_battery_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("David Lechner <david@lechnology.com>");
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MODULE_DESCRIPTION("LEGO MINDSTORMS EV3 Battery Driver");
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