blob: 7ef445a6cfa6d824f297c39ad0b93555126fd82e [file] [log] [blame]
Marek Beliskoda0a00e2013-08-29 11:41:52 +02001/*
2 * Dumb driver for LiIon batteries using TWL4030 madc.
3 *
4 * Copyright 2013 Golden Delicious Computers
5 * Lukas Märdian <lukas@goldelico.com>
6 *
7 * Based on dumb driver for gta01 battery
8 * Copyright 2009 Openmoko, Inc
9 * Balaji Rao <balajirrao@openmoko.org>
10 */
11
12#include <linux/module.h>
13#include <linux/param.h>
14#include <linux/delay.h>
15#include <linux/workqueue.h>
16#include <linux/platform_device.h>
17#include <linux/power_supply.h>
18#include <linux/slab.h>
19#include <linux/sort.h>
20#include <linux/i2c/twl4030-madc.h>
21#include <linux/power/twl4030_madc_battery.h>
22
23struct twl4030_madc_battery {
24 struct power_supply psy;
25 struct twl4030_madc_bat_platform_data *pdata;
26};
27
28static enum power_supply_property twl4030_madc_bat_props[] = {
29 POWER_SUPPLY_PROP_PRESENT,
30 POWER_SUPPLY_PROP_STATUS,
31 POWER_SUPPLY_PROP_TECHNOLOGY,
32 POWER_SUPPLY_PROP_VOLTAGE_NOW,
33 POWER_SUPPLY_PROP_CURRENT_NOW,
34 POWER_SUPPLY_PROP_CAPACITY,
35 POWER_SUPPLY_PROP_CHARGE_FULL,
36 POWER_SUPPLY_PROP_CHARGE_NOW,
37 POWER_SUPPLY_PROP_TEMP,
38 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
39};
40
41static int madc_read(int index)
42{
43 struct twl4030_madc_request req;
44 int val;
45
46 req.channels = index;
47 req.method = TWL4030_MADC_SW2;
48 req.type = TWL4030_MADC_WAIT;
49 req.do_avg = 0;
50 req.raw = false;
51 req.func_cb = NULL;
52
53 val = twl4030_madc_conversion(&req);
54 if (val < 0)
55 return val;
56
57 return req.rbuf[ffs(index) - 1];
58}
59
60static int twl4030_madc_bat_get_charging_status(void)
61{
62 return (madc_read(TWL4030_MADC_ICHG) > 0) ? 1 : 0;
63}
64
65static int twl4030_madc_bat_get_voltage(void)
66{
67 return madc_read(TWL4030_MADC_VBAT);
68}
69
70static int twl4030_madc_bat_get_current(void)
71{
72 return madc_read(TWL4030_MADC_ICHG) * 1000;
73}
74
75static int twl4030_madc_bat_get_temp(void)
76{
77 return madc_read(TWL4030_MADC_BTEMP) * 10;
78}
79
80static int twl4030_madc_bat_voltscale(struct twl4030_madc_battery *bat,
81 int volt)
82{
83 struct twl4030_madc_bat_calibration *calibration;
84 int i, res = 0;
85
86 /* choose charging curve */
87 if (twl4030_madc_bat_get_charging_status())
88 calibration = bat->pdata->charging;
89 else
90 calibration = bat->pdata->discharging;
91
92 if (volt > calibration[0].voltage) {
93 res = calibration[0].level;
94 } else {
95 for (i = 0; calibration[i+1].voltage >= 0; i++) {
96 if (volt <= calibration[i].voltage &&
97 volt >= calibration[i+1].voltage) {
98 /* interval found - interpolate within range */
99 res = calibration[i].level -
100 ((calibration[i].voltage - volt) *
101 (calibration[i].level -
102 calibration[i+1].level)) /
103 (calibration[i].voltage -
104 calibration[i+1].voltage);
105 break;
106 }
107 }
108 }
109 return res;
110}
111
112static int twl4030_madc_bat_get_property(struct power_supply *psy,
113 enum power_supply_property psp,
114 union power_supply_propval *val)
115{
116 struct twl4030_madc_battery *bat = container_of(psy,
117 struct twl4030_madc_battery, psy);
118
119 switch (psp) {
120 case POWER_SUPPLY_PROP_STATUS:
121 if (twl4030_madc_bat_voltscale(bat,
122 twl4030_madc_bat_get_voltage()) > 95)
123 val->intval = POWER_SUPPLY_STATUS_FULL;
124 else {
125 if (twl4030_madc_bat_get_charging_status())
126 val->intval = POWER_SUPPLY_STATUS_CHARGING;
127 else
128 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
129 }
130 break;
131 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
132 val->intval = twl4030_madc_bat_get_voltage() * 1000;
133 break;
134 case POWER_SUPPLY_PROP_TECHNOLOGY:
135 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
136 break;
137 case POWER_SUPPLY_PROP_CURRENT_NOW:
138 val->intval = twl4030_madc_bat_get_current();
139 break;
140 case POWER_SUPPLY_PROP_PRESENT:
141 /* assume battery is always present */
142 val->intval = 1;
143 break;
144 case POWER_SUPPLY_PROP_CHARGE_NOW: {
145 int percent = twl4030_madc_bat_voltscale(bat,
146 twl4030_madc_bat_get_voltage());
147 val->intval = (percent * bat->pdata->capacity) / 100;
148 break;
149 }
150 case POWER_SUPPLY_PROP_CAPACITY:
151 val->intval = twl4030_madc_bat_voltscale(bat,
152 twl4030_madc_bat_get_voltage());
153 break;
154 case POWER_SUPPLY_PROP_CHARGE_FULL:
155 val->intval = bat->pdata->capacity;
156 break;
157 case POWER_SUPPLY_PROP_TEMP:
158 val->intval = twl4030_madc_bat_get_temp();
159 break;
160 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: {
161 int percent = twl4030_madc_bat_voltscale(bat,
162 twl4030_madc_bat_get_voltage());
163 /* in mAh */
164 int chg = (percent * (bat->pdata->capacity/1000))/100;
165
166 /* assume discharge with 400 mA (ca. 1.5W) */
167 val->intval = (3600l * chg) / 400;
168 break;
169 }
170 default:
171 return -EINVAL;
172 }
173
174 return 0;
175}
176
177static void twl4030_madc_bat_ext_changed(struct power_supply *psy)
178{
179 struct twl4030_madc_battery *bat = container_of(psy,
180 struct twl4030_madc_battery, psy);
181
182 power_supply_changed(&bat->psy);
183}
184
185static int twl4030_cmp(const void *a, const void *b)
186{
187 return ((struct twl4030_madc_bat_calibration *)b)->voltage -
188 ((struct twl4030_madc_bat_calibration *)a)->voltage;
189}
190
191static int twl4030_madc_battery_probe(struct platform_device *pdev)
192{
193 struct twl4030_madc_battery *twl4030_madc_bat;
194 struct twl4030_madc_bat_platform_data *pdata = pdev->dev.platform_data;
195
196 twl4030_madc_bat = kzalloc(sizeof(*twl4030_madc_bat), GFP_KERNEL);
197 if (!twl4030_madc_bat)
198 return -ENOMEM;
199
200 twl4030_madc_bat->psy.name = "twl4030_battery";
201 twl4030_madc_bat->psy.type = POWER_SUPPLY_TYPE_BATTERY;
202 twl4030_madc_bat->psy.properties = twl4030_madc_bat_props;
203 twl4030_madc_bat->psy.num_properties =
204 ARRAY_SIZE(twl4030_madc_bat_props);
205 twl4030_madc_bat->psy.get_property = twl4030_madc_bat_get_property;
206 twl4030_madc_bat->psy.external_power_changed =
207 twl4030_madc_bat_ext_changed;
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 platform_set_drvdata(pdev, twl4030_madc_bat);
219 power_supply_register(&pdev->dev, &twl4030_madc_bat->psy);
220
221 return 0;
222}
223
224static int twl4030_madc_battery_remove(struct platform_device *pdev)
225{
226 struct twl4030_madc_battery *bat = platform_get_drvdata(pdev);
227
228 power_supply_unregister(&bat->psy);
229 kfree(bat);
230
231 return 0;
232}
233
234static struct platform_driver twl4030_madc_battery_driver = {
235 .driver = {
236 .name = "twl4030_madc_battery",
237 },
238 .probe = twl4030_madc_battery_probe,
239 .remove = twl4030_madc_battery_remove,
240};
241module_platform_driver(twl4030_madc_battery_driver);
242
243MODULE_LICENSE("GPL");
244MODULE_AUTHOR("Lukas Märdian <lukas@goldelico.com>");
245MODULE_DESCRIPTION("twl4030_madc battery driver");