1 // SPDX-License-Identifier: GPL-2.0
3 * Battery driver for the Ingenic JZ47xx SoCs
4 * Copyright (c) 2019 Artur Rojek <contact@artur-rojek.eu>
6 * based on drivers/power/supply/jz4740-battery.c
9 #include <linux/iio/consumer.h>
10 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/power_supply.h>
14 #include <linux/property.h>
16 struct ingenic_battery {
18 struct iio_channel *channel;
19 struct power_supply_desc desc;
20 struct power_supply *battery;
21 struct power_supply_battery_info info;
24 static int ingenic_battery_get_property(struct power_supply *psy,
25 enum power_supply_property psp,
26 union power_supply_propval *val)
28 struct ingenic_battery *bat = power_supply_get_drvdata(psy);
29 struct power_supply_battery_info *info = &bat->info;
33 case POWER_SUPPLY_PROP_HEALTH:
34 ret = iio_read_channel_processed(bat->channel, &val->intval);
36 if (val->intval < info->voltage_min_design_uv)
37 val->intval = POWER_SUPPLY_HEALTH_DEAD;
38 else if (val->intval > info->voltage_max_design_uv)
39 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
41 val->intval = POWER_SUPPLY_HEALTH_GOOD;
43 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
44 ret = iio_read_channel_processed(bat->channel, &val->intval);
47 case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
48 val->intval = info->voltage_min_design_uv;
50 case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
51 val->intval = info->voltage_max_design_uv;
58 /* Set the most appropriate IIO channel voltage reference scale
59 * based on the battery's max voltage.
61 static int ingenic_battery_set_scale(struct ingenic_battery *bat)
64 int scale_len, scale_type, best_idx = -1, best_mV, max_raw, i, ret;
67 ret = iio_read_max_channel_raw(bat->channel, &max_raw);
69 dev_err(bat->dev, "Unable to read max raw channel value\n");
73 ret = iio_read_avail_channel_attribute(bat->channel, &scale_raw,
74 &scale_type, &scale_len,
77 dev_err(bat->dev, "Unable to read channel avail scale\n");
80 if (ret != IIO_AVAIL_LIST || scale_type != IIO_VAL_FRACTIONAL_LOG2)
83 max_mV = bat->info.voltage_max_design_uv / 1000;
85 for (i = 0; i < scale_len; i += 2) {
86 u64 scale_mV = (max_raw * scale_raw[i]) >> scale_raw[i + 1];
88 if (scale_mV < max_mV)
91 if (best_idx >= 0 && scale_mV > best_mV)
99 dev_err(bat->dev, "Unable to find matching voltage scale\n");
103 return iio_write_channel_attribute(bat->channel,
105 scale_raw[best_idx + 1],
106 IIO_CHAN_INFO_SCALE);
109 static enum power_supply_property ingenic_battery_properties[] = {
110 POWER_SUPPLY_PROP_HEALTH,
111 POWER_SUPPLY_PROP_VOLTAGE_NOW,
112 POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
113 POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
116 static int ingenic_battery_probe(struct platform_device *pdev)
118 struct device *dev = &pdev->dev;
119 struct ingenic_battery *bat;
120 struct power_supply_config psy_cfg = {};
121 struct power_supply_desc *desc;
124 bat = devm_kzalloc(dev, sizeof(*bat), GFP_KERNEL);
129 bat->channel = devm_iio_channel_get(dev, "battery");
130 if (IS_ERR(bat->channel))
131 return PTR_ERR(bat->channel);
134 desc->name = "jz-battery";
135 desc->type = POWER_SUPPLY_TYPE_BATTERY;
136 desc->properties = ingenic_battery_properties;
137 desc->num_properties = ARRAY_SIZE(ingenic_battery_properties);
138 desc->get_property = ingenic_battery_get_property;
139 psy_cfg.drv_data = bat;
140 psy_cfg.of_node = dev->of_node;
142 bat->battery = devm_power_supply_register(dev, desc, &psy_cfg);
143 if (IS_ERR(bat->battery)) {
144 dev_err(dev, "Unable to register battery\n");
145 return PTR_ERR(bat->battery);
148 ret = power_supply_get_battery_info(bat->battery, &bat->info);
150 dev_err(dev, "Unable to get battery info: %d\n", ret);
153 if (bat->info.voltage_min_design_uv < 0) {
154 dev_err(dev, "Unable to get voltage min design\n");
155 return bat->info.voltage_min_design_uv;
157 if (bat->info.voltage_max_design_uv < 0) {
158 dev_err(dev, "Unable to get voltage max design\n");
159 return bat->info.voltage_max_design_uv;
162 return ingenic_battery_set_scale(bat);
166 static const struct of_device_id ingenic_battery_of_match[] = {
167 { .compatible = "ingenic,jz4740-battery", },
170 MODULE_DEVICE_TABLE(of, ingenic_battery_of_match);
173 static struct platform_driver ingenic_battery_driver = {
175 .name = "ingenic-battery",
176 .of_match_table = of_match_ptr(ingenic_battery_of_match),
178 .probe = ingenic_battery_probe,
180 module_platform_driver(ingenic_battery_driver);
182 MODULE_DESCRIPTION("Battery driver for Ingenic JZ47xx SoCs");
183 MODULE_AUTHOR("Artur Rojek <contact@artur-rojek.eu>");
184 MODULE_LICENSE("GPL");