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 int ret = 0;
192
193 twl4030_madc_bat = devm_kzalloc(&pdev->dev, sizeof(*twl4030_madc_bat),
194 GFP_KERNEL);
195 if (!twl4030_madc_bat)
196 return -ENOMEM;
197
198 twl4030_madc_bat->channel_temp = iio_channel_get(&pdev->dev, "temp");
199 if (IS_ERR(twl4030_madc_bat->channel_temp)) {
200 ret = PTR_ERR(twl4030_madc_bat->channel_temp);
201 goto err;
202 }
203
204 twl4030_madc_bat->channel_ichg = iio_channel_get(&pdev->dev, "ichg");
205 if (IS_ERR(twl4030_madc_bat->channel_ichg)) {
206 ret = PTR_ERR(twl4030_madc_bat->channel_ichg);
207 goto err_temp;
208 }
209
210 twl4030_madc_bat->channel_vbat = iio_channel_get(&pdev->dev, "vbat");
211 if (IS_ERR(twl4030_madc_bat->channel_vbat)) {
212 ret = PTR_ERR(twl4030_madc_bat->channel_vbat);
213 goto err_ichg;
214 }
215
216 /* sort charging and discharging calibration data */
217 sort(pdata->charging, pdata->charging_size,
218 sizeof(struct twl4030_madc_bat_calibration),
219 twl4030_cmp, NULL);
220 sort(pdata->discharging, pdata->discharging_size,
221 sizeof(struct twl4030_madc_bat_calibration),
222 twl4030_cmp, NULL);
223
224 twl4030_madc_bat->pdata = pdata;
225 platform_set_drvdata(pdev, twl4030_madc_bat);
226 psy_cfg.drv_data = twl4030_madc_bat;
227 twl4030_madc_bat->psy = power_supply_register(&pdev->dev,
228 &twl4030_madc_bat_desc,
229 &psy_cfg);
230 if (IS_ERR(twl4030_madc_bat->psy)) {
231 ret = PTR_ERR(twl4030_madc_bat->psy);
232 goto err_vbat;
233 }
234
235 return 0;
236
237 err_vbat:
238 iio_channel_release(twl4030_madc_bat->channel_vbat);
239 err_ichg:
240 iio_channel_release(twl4030_madc_bat->channel_ichg);
241 err_temp:
242 iio_channel_release(twl4030_madc_bat->channel_temp);
243 err:
244 return ret;
245 }
246
twl4030_madc_battery_remove(struct platform_device * pdev)247 static int twl4030_madc_battery_remove(struct platform_device *pdev)
248 {
249 struct twl4030_madc_battery *bat = platform_get_drvdata(pdev);
250
251 power_supply_unregister(bat->psy);
252
253 iio_channel_release(bat->channel_vbat);
254 iio_channel_release(bat->channel_ichg);
255 iio_channel_release(bat->channel_temp);
256
257 return 0;
258 }
259
260 static struct platform_driver twl4030_madc_battery_driver = {
261 .driver = {
262 .name = "twl4030_madc_battery",
263 },
264 .probe = twl4030_madc_battery_probe,
265 .remove = twl4030_madc_battery_remove,
266 };
267 module_platform_driver(twl4030_madc_battery_driver);
268
269 MODULE_LICENSE("GPL");
270 MODULE_AUTHOR("Lukas Märdian <lukas@goldelico.com>");
271 MODULE_DESCRIPTION("twl4030_madc battery driver");
272 MODULE_ALIAS("platform:twl4030_madc_battery");
273