1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
|
/*
* Nokia RX-51 battery driver
*
* Copyright (C) 2012 Pali Rohár <pali.rohar@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/module.h>
#include <linux/param.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/i2c/twl4030-madc.h>
/* RX51 specific channels */
#define TWL4030_MADC_BTEMP_RX51 TWL4030_MADC_ADCIN0
#define TWL4030_MADC_BCI_RX51 TWL4030_MADC_ADCIN4
struct rx51_device_info {
struct device *dev;
struct power_supply bat;
};
/*
* Read ADCIN channel value, code copied from maemo kernel
*/
static int rx51_battery_read_adc(int channel)
{
struct twl4030_madc_request req;
req.channels = channel;
req.do_avg = 1;
req.method = TWL4030_MADC_SW1;
req.func_cb = NULL;
req.type = TWL4030_MADC_WAIT;
req.raw = true;
if (twl4030_madc_conversion(&req) <= 0)
return -ENODATA;
return req.rbuf[channel];
}
/*
* Read ADCIN channel 12 (voltage) and convert RAW value to micro voltage
* This conversion formula was extracted from maemo program bsi-read
*/
static int rx51_battery_read_voltage(struct rx51_device_info *di)
{
int voltage = rx51_battery_read_adc(TWL4030_MADC_VBAT);
if (voltage < 0)
return voltage;
return 1000 * (10000 * voltage / 1705);
}
/*
* Temperature look-up tables
* TEMP = (1/(t1 + 1/298) - 273.15)
* Where t1 = (1/B) * ln((RAW_ADC_U * 2.5)/(R * I * 255))
* Formula is based on experimental data, RX-51 CAL data, maemo program bme
* and formula from da9052 driver with values R = 100, B = 3380, I = 0.00671
*/
/*
* Table1 (temperature for first 25 RAW values)
* Usage: TEMP = rx51_temp_table1[RAW]
* RAW is between 1 and 24
* TEMP is between 201 C and 55 C
*/
static u8 rx51_temp_table1[] = {
255, 201, 159, 138, 124, 114, 106, 99, 94, 89, 85, 82, 78, 75,
73, 70, 68, 66, 64, 62, 61, 59, 57, 56, 55
};
/*
* Table2 (lowest RAW value for temperature)
* Usage: RAW = rx51_temp_table2[TEMP-rx51_temp_table2_first]
* TEMP is between 53 C and -32 C
* RAW is between 25 and 993
*/
#define rx51_temp_table2_first 53
static u16 rx51_temp_table2[] = {
25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 39,
40, 41, 43, 44, 46, 48, 49, 51, 53, 55, 57, 59, 61, 64,
66, 69, 71, 74, 77, 80, 83, 86, 90, 94, 97, 101, 106, 110,
115, 119, 125, 130, 136, 141, 148, 154, 161, 168, 176, 184, 202, 211,
221, 231, 242, 254, 266, 279, 293, 308, 323, 340, 357, 375, 395, 415,
437, 460, 485, 511, 539, 568, 600, 633, 669, 706, 747, 790, 836, 885,
937, 993, 1024
};
/*
* Read ADCIN channel 0 (battery temp) and convert value to tenths of Celsius
* Use Temperature look-up tables for conversation
*/
static int rx51_battery_read_temperature(struct rx51_device_info *di)
{
int min = 0;
int max = ARRAY_SIZE(rx51_temp_table2) - 1;
int raw = rx51_battery_read_adc(TWL4030_MADC_BTEMP_RX51);
/* Zero and negative values are undefined */
if (raw <= 0)
return INT_MAX;
/* ADC channels are 10 bit, higher value are undefined */
if (raw >= (1 << 10))
return INT_MIN;
/* First check for temperature in first direct table */
if (raw < ARRAY_SIZE(rx51_temp_table1))
return rx51_temp_table1[raw] * 10;
/* Binary search RAW value in second inverse table */
while (max - min > 1) {
int mid = (max + min) / 2;
if (rx51_temp_table2[mid] <= raw)
min = mid;
else if (rx51_temp_table2[mid] > raw)
max = mid;
if (rx51_temp_table2[mid] == raw)
break;
}
return (rx51_temp_table2_first - min) * 10;
}
/*
* Read ADCIN channel 4 (BSI) and convert RAW value to micro Ah
* This conversion formula was extracted from maemo program bsi-read
*/
static int rx51_battery_read_capacity(struct rx51_device_info *di)
{
int capacity = rx51_battery_read_adc(TWL4030_MADC_BCI_RX51);
if (capacity < 0)
return capacity;
return 1280 * (1200 * capacity)/(1024 - capacity);
}
/*
* Return power_supply property
*/
static int rx51_battery_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct rx51_device_info *di = container_of((psy),
struct rx51_device_info, bat);
switch (psp) {
case POWER_SUPPLY_PROP_TECHNOLOGY:
val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
break;
case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
val->intval = 4200000;
break;
case POWER_SUPPLY_PROP_PRESENT:
val->intval = rx51_battery_read_voltage(di) ? 1 : 0;
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = rx51_battery_read_voltage(di);
break;
case POWER_SUPPLY_PROP_TEMP:
val->intval = rx51_battery_read_temperature(di);
break;
case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
val->intval = rx51_battery_read_capacity(di);
break;
default:
return -EINVAL;
}
if (val->intval == INT_MAX || val->intval == INT_MIN)
return -EINVAL;
return 0;
}
static enum power_supply_property rx51_battery_props[] = {
POWER_SUPPLY_PROP_TECHNOLOGY,
POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_TEMP,
POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
};
static int rx51_battery_probe(struct platform_device *pdev)
{
struct rx51_device_info *di;
int ret;
di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
if (!di)
return -ENOMEM;
platform_set_drvdata(pdev, di);
di->bat.name = dev_name(&pdev->dev);
di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
di->bat.properties = rx51_battery_props;
di->bat.num_properties = ARRAY_SIZE(rx51_battery_props);
di->bat.get_property = rx51_battery_get_property;
ret = power_supply_register(di->dev, &di->bat);
if (ret)
return ret;
return 0;
}
static int rx51_battery_remove(struct platform_device *pdev)
{
struct rx51_device_info *di = platform_get_drvdata(pdev);
power_supply_unregister(&di->bat);
return 0;
}
static struct platform_driver rx51_battery_driver = {
.probe = rx51_battery_probe,
.remove = rx51_battery_remove,
.driver = {
.name = "rx51-battery",
.owner = THIS_MODULE,
},
};
module_platform_driver(rx51_battery_driver);
MODULE_ALIAS("platform:rx51-battery");
MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
MODULE_DESCRIPTION("Nokia RX-51 battery driver");
MODULE_LICENSE("GPL");
|
