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1 | /* |
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 | ||
23 | struct twl4030_madc_battery { | |
24 | struct power_supply psy; | |
25 | struct twl4030_madc_bat_platform_data *pdata; | |
26 | }; | |
27 | ||
28 | static 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 | ||
41 | static 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 | ||
60 | static int twl4030_madc_bat_get_charging_status(void) | |
61 | { | |
62 | return (madc_read(TWL4030_MADC_ICHG) > 0) ? 1 : 0; | |
63 | } | |
64 | ||
65 | static int twl4030_madc_bat_get_voltage(void) | |
66 | { | |
67 | return madc_read(TWL4030_MADC_VBAT); | |
68 | } | |
69 | ||
70 | static int twl4030_madc_bat_get_current(void) | |
71 | { | |
72 | return madc_read(TWL4030_MADC_ICHG) * 1000; | |
73 | } | |
74 | ||
75 | static int twl4030_madc_bat_get_temp(void) | |
76 | { | |
77 | return madc_read(TWL4030_MADC_BTEMP) * 10; | |
78 | } | |
79 | ||
80 | static 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 | ||
112 | static 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 | ||
177 | static 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 | ||
185 | static 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 | ||
191 | static 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 | ||
224 | static 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 | ||
234 | static 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 | }; | |
241 | module_platform_driver(twl4030_madc_battery_driver); | |
242 | ||
243 | MODULE_LICENSE("GPL"); | |
244 | MODULE_AUTHOR("Lukas Märdian <lukas@goldelico.com>"); | |
245 | MODULE_DESCRIPTION("twl4030_madc battery driver"); |