1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Nokia RX-51 battery driver
39  * This conversion formula was extracted from maemo program bsi-read
43 	int voltage = rx51_battery_read_adc(di->channel_vbat);  in rx51_battery_read_voltage()
46 		dev_err(di->dev, "Could not read ADC: %d\n", voltage);  in rx51_battery_read_voltage()
54  * Temperature look-up tables
55  * TEMP = (1/(t1 + 1/298) - 273.15)
57  * Formula is based on experimental data, RX-51 CAL data, maemo program bme
74  * Usage: RAW = rx51_temp_table2[TEMP-rx51_temp_table2_first]
75  *   TEMP is between 53 C and -32 C
90  * Read ADCIN channel 0 (battery temp) and convert value to tenths of Celsius
91  * Use Temperature look-up tables for conversation
96 	int max = ARRAY_SIZE(rx51_temp_table2) - 1;  in rx51_battery_read_temperature()
97 	int raw = rx51_battery_read_adc(di->channel_temp);  in rx51_battery_read_temperature()
100 		dev_err(di->dev, "Could not read ADC: %d\n", raw);  in rx51_battery_read_temperature()
106 	/* ADC channels are 10 bit, higher value are undefined */  in rx51_battery_read_temperature()
115 	while (max - min > 1) {  in rx51_battery_read_temperature()
125 	return (rx51_temp_table2_first - min) * 10;  in rx51_battery_read_temperature()
130  * This conversion formula was extracted from maemo program bsi-read
134 	int capacity = rx51_battery_read_adc(di->channel_bsi);  in rx51_battery_read_capacity()
137 		dev_err(di->dev, "Could not read ADC: %d\n", capacity);  in rx51_battery_read_capacity()
141 	return 1280 * (1200 * capacity)/(1024 - capacity);  in rx51_battery_read_capacity()
155 		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;  in rx51_battery_get_property()
158 		val->intval = 4200000;  in rx51_battery_get_property()
161 		val->intval = rx51_battery_read_voltage(di) ? 1 : 0;  in rx51_battery_get_property()
164 		val->intval = rx51_battery_read_voltage(di);  in rx51_battery_get_property()
167 		val->intval = rx51_battery_read_temperature(di);  in rx51_battery_get_property()
170 		val->intval = rx51_battery_read_capacity(di);  in rx51_battery_get_property()
173 		return -EINVAL;  in rx51_battery_get_property()
176 	if (val->intval == INT_MAX || val->intval == INT_MIN)  in rx51_battery_get_property()
177 		return -EINVAL;  in rx51_battery_get_property()
197 	di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);  in rx51_battery_probe()
199 		return -ENOMEM;  in rx51_battery_probe()
203 	di->dev = &pdev->dev;  in rx51_battery_probe()
204 	di->bat_desc.name = "rx51-battery";  in rx51_battery_probe()
205 	di->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;  in rx51_battery_probe()
206 	di->bat_desc.properties = rx51_battery_props;  in rx51_battery_probe()
207 	di->bat_desc.num_properties = ARRAY_SIZE(rx51_battery_props);  in rx51_battery_probe()
208 	di->bat_desc.get_property = rx51_battery_get_property;  in rx51_battery_probe()
212 	di->channel_temp = iio_channel_get(di->dev, "temp");  in rx51_battery_probe()
213 	if (IS_ERR(di->channel_temp)) {  in rx51_battery_probe()
214 		ret = PTR_ERR(di->channel_temp);  in rx51_battery_probe()
218 	di->channel_bsi  = iio_channel_get(di->dev, "bsi");  in rx51_battery_probe()
219 	if (IS_ERR(di->channel_bsi)) {  in rx51_battery_probe()
220 		ret = PTR_ERR(di->channel_bsi);  in rx51_battery_probe()
224 	di->channel_vbat = iio_channel_get(di->dev, "vbat");  in rx51_battery_probe()
225 	if (IS_ERR(di->channel_vbat)) {  in rx51_battery_probe()
226 		ret = PTR_ERR(di->channel_vbat);  in rx51_battery_probe()
230 	di->bat = power_supply_register(di->dev, &di->bat_desc, &psy_cfg);  in rx51_battery_probe()
231 	if (IS_ERR(di->bat)) {  in rx51_battery_probe()
232 		ret = PTR_ERR(di->bat);  in rx51_battery_probe()
239 	iio_channel_release(di->channel_vbat);  in rx51_battery_probe()
241 	iio_channel_release(di->channel_bsi);  in rx51_battery_probe()
243 	iio_channel_release(di->channel_temp);  in rx51_battery_probe()
253 	power_supply_unregister(di->bat);  in rx51_battery_remove()
255 	iio_channel_release(di->channel_vbat);  in rx51_battery_remove()
256 	iio_channel_release(di->channel_bsi);  in rx51_battery_remove()
257 	iio_channel_release(di->channel_temp);  in rx51_battery_remove()
264 	{.compatible = "nokia,n900-battery", },
274 		.name = "rx51-battery",
280 MODULE_ALIAS("platform:rx51-battery");
282 MODULE_DESCRIPTION("Nokia RX-51 battery driver");