2 * Dumb driver for LiIon batteries using TWL4030 madc.
4 * Copyright 2013 Golden Delicious Computers
5 * Lukas Märdian <lukas@goldelico.com>
7 * Based on dumb driver for gta01 battery
8 * Copyright 2009 Openmoko, Inc
9 * Balaji Rao <balajirrao@openmoko.org>
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>
23 struct twl4030_madc_battery
{
24 struct power_supply
*psy
;
25 struct twl4030_madc_bat_platform_data
*pdata
;
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
,
41 static int madc_read(int index
)
43 struct twl4030_madc_request req
;
47 req
.method
= TWL4030_MADC_SW2
;
48 req
.type
= TWL4030_MADC_WAIT
;
53 val
= twl4030_madc_conversion(&req
);
57 return req
.rbuf
[ffs(index
) - 1];
60 static int twl4030_madc_bat_get_charging_status(void)
62 return (madc_read(TWL4030_MADC_ICHG
) > 0) ? 1 : 0;
65 static int twl4030_madc_bat_get_voltage(void)
67 return madc_read(TWL4030_MADC_VBAT
);
70 static int twl4030_madc_bat_get_current(void)
72 return madc_read(TWL4030_MADC_ICHG
) * 1000;
75 static int twl4030_madc_bat_get_temp(void)
77 return madc_read(TWL4030_MADC_BTEMP
) * 10;
80 static int twl4030_madc_bat_voltscale(struct twl4030_madc_battery
*bat
,
83 struct twl4030_madc_bat_calibration
*calibration
;
86 /* choose charging curve */
87 if (twl4030_madc_bat_get_charging_status())
88 calibration
= bat
->pdata
->charging
;
90 calibration
= bat
->pdata
->discharging
;
92 if (volt
> calibration
[0].voltage
) {
93 res
= calibration
[0].level
;
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
);
112 static int twl4030_madc_bat_get_property(struct power_supply
*psy
,
113 enum power_supply_property psp
,
114 union power_supply_propval
*val
)
116 struct twl4030_madc_battery
*bat
= power_supply_get_drvdata(psy
);
119 case POWER_SUPPLY_PROP_STATUS
:
120 if (twl4030_madc_bat_voltscale(bat
,
121 twl4030_madc_bat_get_voltage()) > 95)
122 val
->intval
= POWER_SUPPLY_STATUS_FULL
;
124 if (twl4030_madc_bat_get_charging_status())
125 val
->intval
= POWER_SUPPLY_STATUS_CHARGING
;
127 val
->intval
= POWER_SUPPLY_STATUS_DISCHARGING
;
130 case POWER_SUPPLY_PROP_VOLTAGE_NOW
:
131 val
->intval
= twl4030_madc_bat_get_voltage() * 1000;
133 case POWER_SUPPLY_PROP_TECHNOLOGY
:
134 val
->intval
= POWER_SUPPLY_TECHNOLOGY_LION
;
136 case POWER_SUPPLY_PROP_CURRENT_NOW
:
137 val
->intval
= twl4030_madc_bat_get_current();
139 case POWER_SUPPLY_PROP_PRESENT
:
140 /* assume battery is always present */
143 case POWER_SUPPLY_PROP_CHARGE_NOW
: {
144 int percent
= twl4030_madc_bat_voltscale(bat
,
145 twl4030_madc_bat_get_voltage());
146 val
->intval
= (percent
* bat
->pdata
->capacity
) / 100;
149 case POWER_SUPPLY_PROP_CAPACITY
:
150 val
->intval
= twl4030_madc_bat_voltscale(bat
,
151 twl4030_madc_bat_get_voltage());
153 case POWER_SUPPLY_PROP_CHARGE_FULL
:
154 val
->intval
= bat
->pdata
->capacity
;
156 case POWER_SUPPLY_PROP_TEMP
:
157 val
->intval
= twl4030_madc_bat_get_temp();
159 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW
: {
160 int percent
= twl4030_madc_bat_voltscale(bat
,
161 twl4030_madc_bat_get_voltage());
163 int chg
= (percent
* (bat
->pdata
->capacity
/1000))/100;
165 /* assume discharge with 400 mA (ca. 1.5W) */
166 val
->intval
= (3600l * chg
) / 400;
176 static void twl4030_madc_bat_ext_changed(struct power_supply
*psy
)
178 power_supply_changed(psy
);
181 static const struct power_supply_desc twl4030_madc_bat_desc
= {
182 .name
= "twl4030_battery",
183 .type
= POWER_SUPPLY_TYPE_BATTERY
,
184 .properties
= twl4030_madc_bat_props
,
185 .num_properties
= ARRAY_SIZE(twl4030_madc_bat_props
),
186 .get_property
= twl4030_madc_bat_get_property
,
187 .external_power_changed
= twl4030_madc_bat_ext_changed
,
191 static int twl4030_cmp(const void *a
, const void *b
)
193 return ((struct twl4030_madc_bat_calibration
*)b
)->voltage
-
194 ((struct twl4030_madc_bat_calibration
*)a
)->voltage
;
197 static int twl4030_madc_battery_probe(struct platform_device
*pdev
)
199 struct twl4030_madc_battery
*twl4030_madc_bat
;
200 struct twl4030_madc_bat_platform_data
*pdata
= pdev
->dev
.platform_data
;
201 struct power_supply_config psy_cfg
= {};
204 twl4030_madc_bat
= kzalloc(sizeof(*twl4030_madc_bat
), GFP_KERNEL
);
205 if (!twl4030_madc_bat
)
208 /* sort charging and discharging calibration data */
209 sort(pdata
->charging
, pdata
->charging_size
,
210 sizeof(struct twl4030_madc_bat_calibration
),
212 sort(pdata
->discharging
, pdata
->discharging_size
,
213 sizeof(struct twl4030_madc_bat_calibration
),
216 twl4030_madc_bat
->pdata
= pdata
;
217 platform_set_drvdata(pdev
, twl4030_madc_bat
);
218 psy_cfg
.drv_data
= twl4030_madc_bat
;
219 twl4030_madc_bat
->psy
= power_supply_register(&pdev
->dev
,
220 &twl4030_madc_bat_desc
,
222 if (IS_ERR(twl4030_madc_bat
->psy
)) {
223 ret
= PTR_ERR(twl4030_madc_bat
->psy
);
224 kfree(twl4030_madc_bat
);
230 static int twl4030_madc_battery_remove(struct platform_device
*pdev
)
232 struct twl4030_madc_battery
*bat
= platform_get_drvdata(pdev
);
234 power_supply_unregister(bat
->psy
);
240 static struct platform_driver twl4030_madc_battery_driver
= {
242 .name
= "twl4030_madc_battery",
244 .probe
= twl4030_madc_battery_probe
,
245 .remove
= twl4030_madc_battery_remove
,
247 module_platform_driver(twl4030_madc_battery_driver
);
249 MODULE_LICENSE("GPL");
250 MODULE_AUTHOR("Lukas Märdian <lukas@goldelico.com>");
251 MODULE_DESCRIPTION("twl4030_madc battery driver");