1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Dumb driver for LiIon batteries using TWL4030 madc.
4 *
5 * Copyright 2013 Golden Delicious Computers
6 * Lukas Märdian <lukas@goldelico.com>
7 *
8 * Based on dumb driver for gta01 battery
9 * Copyright 2009 Openmoko, Inc
10 * Balaji Rao <balajirrao@openmoko.org>
11 */
12
13 #include <linux/module.h>
14 #include <linux/param.h>
15 #include <linux/delay.h>
16 #include <linux/workqueue.h>
17 #include <linux/platform_device.h>
18 #include <linux/power_supply.h>
19 #include <linux/slab.h>
20 #include <linux/sort.h>
21 #include <linux/power/twl4030_madc_battery.h>
22 #include <linux/iio/consumer.h>
23
24 struct twl4030_madc_battery {
25 struct power_supply *psy;
26 struct twl4030_madc_bat_platform_data *pdata;
27 struct iio_channel *channel_temp;
28 struct iio_channel *channel_ichg;
29 struct iio_channel *channel_vbat;
30 };
31
32 static enum power_supply_property twl4030_madc_bat_props[] = {
33 POWER_SUPPLY_PROP_PRESENT,
34 POWER_SUPPLY_PROP_STATUS,
35 POWER_SUPPLY_PROP_TECHNOLOGY,
36 POWER_SUPPLY_PROP_VOLTAGE_NOW,
37 POWER_SUPPLY_PROP_CURRENT_NOW,
38 POWER_SUPPLY_PROP_CAPACITY,
39 POWER_SUPPLY_PROP_CHARGE_FULL,
40 POWER_SUPPLY_PROP_CHARGE_NOW,
41 POWER_SUPPLY_PROP_TEMP,
42 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
43 };
44
madc_read(struct iio_channel * channel)45 static int madc_read(struct iio_channel *channel)
46 {
47 int val, err;
48 err = iio_read_channel_processed(channel, &val);
49 if (err < 0)
50 return err;
51
52 return val;
53 }
54
twl4030_madc_bat_get_charging_status(struct twl4030_madc_battery * bt)55 static int twl4030_madc_bat_get_charging_status(struct twl4030_madc_battery *bt)
56 {
57 return (madc_read(bt->channel_ichg) > 0) ? 1 : 0;
58 }
59
twl4030_madc_bat_get_voltage(struct twl4030_madc_battery * bt)60 static int twl4030_madc_bat_get_voltage(struct twl4030_madc_battery *bt)
61 {
62 return madc_read(bt->channel_vbat);
63 }
64
twl4030_madc_bat_get_current(struct twl4030_madc_battery * bt)65 static int twl4030_madc_bat_get_current(struct twl4030_madc_battery *bt)
66 {
67 return madc_read(bt->channel_ichg) * 1000;
68 }
69
twl4030_madc_bat_get_temp(struct twl4030_madc_battery * bt)70 static int twl4030_madc_bat_get_temp(struct twl4030_madc_battery *bt)
71 {
72 return madc_read(bt->channel_temp) * 10;
73 }
74
twl4030_madc_bat_voltscale(struct twl4030_madc_battery * bat,int volt)75 static int twl4030_madc_bat_voltscale(struct twl4030_madc_battery *bat,
76 int volt)
77 {
78 struct twl4030_madc_bat_calibration *calibration;
79 int i, res = 0;
80
81 /* choose charging curve */
82 if (twl4030_madc_bat_get_charging_status(bat))
83 calibration = bat->pdata->charging;
84 else
85 calibration = bat->pdata->discharging;
86
87 if (volt > calibration[0].voltage) {
88 res = calibration[0].level;
89 } else {
90 for (i = 0; calibration[i+1].voltage >= 0; i++) {
91 if (volt <= calibration[i].voltage &&
92 volt >= calibration[i+1].voltage) {
93 /* interval found - interpolate within range */
94 res = calibration[i].level -
95 ((calibration[i].voltage - volt) *
96 (calibration[i].level -
97 calibration[i+1].level)) /
98 (calibration[i].voltage -
99 calibration[i+1].voltage);
100 break;
101 }
102 }
103 }
104 return res;
105 }
106
twl4030_madc_bat_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)107 static int twl4030_madc_bat_get_property(struct power_supply *psy,
108 enum power_supply_property psp,
109 union power_supply_propval *val)
110 {
111 struct twl4030_madc_battery *bat = power_supply_get_drvdata(psy);
112
113 switch (psp) {
114 case POWER_SUPPLY_PROP_STATUS:
115 if (twl4030_madc_bat_voltscale(bat,
116 twl4030_madc_bat_get_voltage(bat)) > 95)
117 val->intval = POWER_SUPPLY_STATUS_FULL;
118 else {
119 if (twl4030_madc_bat_get_charging_status(bat))
120 val->intval = POWER_SUPPLY_STATUS_CHARGING;
121 else
122 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
123 }
124 break;
125 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
126 val->intval = twl4030_madc_bat_get_voltage(bat) * 1000;
127 break;
128 case POWER_SUPPLY_PROP_TECHNOLOGY:
129 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
130 break;
131 case POWER_SUPPLY_PROP_CURRENT_NOW:
132 val->intval = twl4030_madc_bat_get_current(bat);
133 break;
134 case POWER_SUPPLY_PROP_PRESENT:
135 /* assume battery is always present */
136 val->intval = 1;
137 break;
138 case POWER_SUPPLY_PROP_CHARGE_NOW: {
139 int percent = twl4030_madc_bat_voltscale(bat,
140 twl4030_madc_bat_get_voltage(bat));
141 val->intval = (percent * bat->pdata->capacity) / 100;
142 break;
143 }
144 case POWER_SUPPLY_PROP_CAPACITY:
145 val->intval = twl4030_madc_bat_voltscale(bat,
146 twl4030_madc_bat_get_voltage(bat));
147 break;
148 case POWER_SUPPLY_PROP_CHARGE_FULL:
149 val->intval = bat->pdata->capacity;
150 break;
151 case POWER_SUPPLY_PROP_TEMP:
152 val->intval = twl4030_madc_bat_get_temp(bat);
153 break;
154 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: {
155 int percent = twl4030_madc_bat_voltscale(bat,
156 twl4030_madc_bat_get_voltage(bat));
157 /* in mAh */
158 int chg = (percent * (bat->pdata->capacity/1000))/100;
159
160 /* assume discharge with 400 mA (ca. 1.5W) */
161 val->intval = (3600l * chg) / 400;
162 break;
163 }
164 default:
165 return -EINVAL;
166 }
167
168 return 0;
169 }
170
171 static const struct power_supply_desc twl4030_madc_bat_desc = {
172 .name = "twl4030_battery",
173 .type = POWER_SUPPLY_TYPE_BATTERY,
174 .properties = twl4030_madc_bat_props,
175 .num_properties = ARRAY_SIZE(twl4030_madc_bat_props),
176 .get_property = twl4030_madc_bat_get_property,
177 .external_power_changed = power_supply_changed,
178 };
179
twl4030_cmp(const void * a,const void * b)180 static int twl4030_cmp(const void *a, const void *b)
181 {
182 return ((struct twl4030_madc_bat_calibration *)b)->voltage -
183 ((struct twl4030_madc_bat_calibration *)a)->voltage;
184 }
185
twl4030_madc_battery_probe(struct platform_device * pdev)186 static int twl4030_madc_battery_probe(struct platform_device *pdev)
187 {
188 struct twl4030_madc_battery *twl4030_madc_bat;
189 struct twl4030_madc_bat_platform_data *pdata = pdev->dev.platform_data;
190 struct power_supply_config psy_cfg = {};
191
192 twl4030_madc_bat = devm_kzalloc(&pdev->dev, sizeof(*twl4030_madc_bat),
193 GFP_KERNEL);
194 if (!twl4030_madc_bat)
195 return -ENOMEM;
196
197 twl4030_madc_bat->channel_temp = devm_iio_channel_get(&pdev->dev, "temp");
198 if (IS_ERR(twl4030_madc_bat->channel_temp))
199 return PTR_ERR(twl4030_madc_bat->channel_temp);
200
201 twl4030_madc_bat->channel_ichg = devm_iio_channel_get(&pdev->dev, "ichg");
202 if (IS_ERR(twl4030_madc_bat->channel_ichg))
203 return PTR_ERR(twl4030_madc_bat->channel_ichg);
204
205 twl4030_madc_bat->channel_vbat = devm_iio_channel_get(&pdev->dev, "vbat");
206 if (IS_ERR(twl4030_madc_bat->channel_vbat))
207 return PTR_ERR(twl4030_madc_bat->channel_vbat);
208
209 /* sort charging and discharging calibration data */
210 sort(pdata->charging, pdata->charging_size,
211 sizeof(struct twl4030_madc_bat_calibration),
212 twl4030_cmp, NULL);
213 sort(pdata->discharging, pdata->discharging_size,
214 sizeof(struct twl4030_madc_bat_calibration),
215 twl4030_cmp, NULL);
216
217 twl4030_madc_bat->pdata = pdata;
218 psy_cfg.drv_data = twl4030_madc_bat;
219 twl4030_madc_bat->psy = devm_power_supply_register(&pdev->dev,
220 &twl4030_madc_bat_desc,
221 &psy_cfg);
222 if (IS_ERR(twl4030_madc_bat->psy))
223 return PTR_ERR(twl4030_madc_bat->psy);
224
225 return 0;
226 }
227
228 static struct platform_driver twl4030_madc_battery_driver = {
229 .driver = {
230 .name = "twl4030_madc_battery",
231 },
232 .probe = twl4030_madc_battery_probe,
233 };
234 module_platform_driver(twl4030_madc_battery_driver);
235
236 MODULE_LICENSE("GPL");
237 MODULE_AUTHOR("Lukas Märdian <lukas@goldelico.com>");
238 MODULE_DESCRIPTION("twl4030_madc battery driver");
239 MODULE_ALIAS("platform:twl4030_madc_battery");
240