Merge branch 'stable/for-jens-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / power / rx51_battery.c
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1/*
2 * Nokia RX-51 battery driver
3 *
4 * Copyright (C) 2012 Pali Rohár <pali.rohar@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21#include <linux/module.h>
22#include <linux/param.h>
23#include <linux/platform_device.h>
24#include <linux/power_supply.h>
25#include <linux/slab.h>
26#include <linux/i2c/twl4030-madc.h>
27
28struct rx51_device_info {
29 struct device *dev;
30 struct power_supply bat;
31};
32
33/*
34 * Read ADCIN channel value, code copied from maemo kernel
35 */
36static int rx51_battery_read_adc(int channel)
37{
38 struct twl4030_madc_request req;
39
40 req.channels = 1 << channel;
41 req.do_avg = 1;
42 req.method = TWL4030_MADC_SW1;
43 req.func_cb = NULL;
44 req.type = TWL4030_MADC_WAIT;
45
46 if (twl4030_madc_conversion(&req) <= 0)
47 return -ENODATA;
48
49 return req.rbuf[channel];
50}
51
52/*
53 * Read ADCIN channel 12 (voltage) and convert RAW value to micro voltage
54 * This conversion formula was extracted from maemo program bsi-read
55 */
56static int rx51_battery_read_voltage(struct rx51_device_info *di)
57{
58 int voltage = rx51_battery_read_adc(12);
59
60 if (voltage < 0)
61 return voltage;
62
63 return 1000 * (10000 * voltage / 1705);
64}
65
66/*
67 * Temperature look-up tables
68 * TEMP = (1/(t1 + 1/298) - 273.15)
69 * Where t1 = (1/B) * ln((RAW_ADC_U * 2.5)/(R * I * 255))
70 * Formula is based on experimental data, RX-51 CAL data, maemo program bme
71 * and formula from da9052 driver with values R = 100, B = 3380, I = 0.00671
72 */
73
74/*
75 * Table1 (temperature for first 25 RAW values)
76 * Usage: TEMP = rx51_temp_table1[RAW]
77 * RAW is between 1 and 24
78 * TEMP is between 201 C and 55 C
79 */
80static u8 rx51_temp_table1[] = {
81 255, 201, 159, 138, 124, 114, 106, 99, 94, 89, 85, 82, 78, 75,
82 73, 70, 68, 66, 64, 62, 61, 59, 57, 56, 55
83};
84
85/*
86 * Table2 (lowest RAW value for temperature)
87 * Usage: RAW = rx51_temp_table2[TEMP-rx51_temp_table2_first]
88 * TEMP is between 53 C and -32 C
89 * RAW is between 25 and 993
90 */
91#define rx51_temp_table2_first 53
92static u16 rx51_temp_table2[] = {
93 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 39,
94 40, 41, 43, 44, 46, 48, 49, 51, 53, 55, 57, 59, 61, 64,
95 66, 69, 71, 74, 77, 80, 83, 86, 90, 94, 97, 101, 106, 110,
96 115, 119, 125, 130, 136, 141, 148, 154, 161, 168, 176, 184, 202, 211,
97 221, 231, 242, 254, 266, 279, 293, 308, 323, 340, 357, 375, 395, 415,
98 437, 460, 485, 511, 539, 568, 600, 633, 669, 706, 747, 790, 836, 885,
99 937, 993, 1024
100};
101
102/*
103 * Read ADCIN channel 0 (battery temp) and convert value to tenths of Celsius
104 * Use Temperature look-up tables for conversation
105 */
106static int rx51_battery_read_temperature(struct rx51_device_info *di)
107{
108 int min = 0;
109 int max = ARRAY_SIZE(rx51_temp_table2) - 1;
110 int raw = rx51_battery_read_adc(0);
111
112 /* Zero and negative values are undefined */
113 if (raw <= 0)
114 return INT_MAX;
115
116 /* ADC channels are 10 bit, higher value are undefined */
117 if (raw >= (1 << 10))
118 return INT_MIN;
119
120 /* First check for temperature in first direct table */
121 if (raw < ARRAY_SIZE(rx51_temp_table1))
122 return rx51_temp_table1[raw] * 100;
123
124 /* Binary search RAW value in second inverse table */
125 while (max - min > 1) {
126 int mid = (max + min) / 2;
127 if (rx51_temp_table2[mid] <= raw)
128 min = mid;
129 else if (rx51_temp_table2[mid] > raw)
130 max = mid;
131 if (rx51_temp_table2[mid] == raw)
132 break;
133 }
134
135 return (rx51_temp_table2_first - min) * 100;
136}
137
138/*
139 * Read ADCIN channel 4 (BSI) and convert RAW value to micro Ah
140 * This conversion formula was extracted from maemo program bsi-read
141 */
142static int rx51_battery_read_capacity(struct rx51_device_info *di)
143{
144 int capacity = rx51_battery_read_adc(4);
145
146 if (capacity < 0)
147 return capacity;
148
149 return 1280 * (1200 * capacity)/(1024 - capacity);
150}
151
152/*
153 * Return power_supply property
154 */
155static int rx51_battery_get_property(struct power_supply *psy,
156 enum power_supply_property psp,
157 union power_supply_propval *val)
158{
159 struct rx51_device_info *di = container_of((psy),
160 struct rx51_device_info, bat);
161
162 switch (psp) {
163 case POWER_SUPPLY_PROP_TECHNOLOGY:
164 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
165 break;
166 case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
167 val->intval = 4200000;
168 break;
169 case POWER_SUPPLY_PROP_PRESENT:
170 val->intval = rx51_battery_read_voltage(di) ? 1 : 0;
171 break;
172 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
173 val->intval = rx51_battery_read_voltage(di);
174 break;
175 case POWER_SUPPLY_PROP_TEMP:
176 val->intval = rx51_battery_read_temperature(di);
177 break;
178 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
179 val->intval = rx51_battery_read_capacity(di);
180 break;
181 default:
182 return -EINVAL;
183 }
184
185 if (val->intval == INT_MAX || val->intval == INT_MIN)
186 return -EINVAL;
187
188 return 0;
189}
190
191static enum power_supply_property rx51_battery_props[] = {
192 POWER_SUPPLY_PROP_TECHNOLOGY,
193 POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
194 POWER_SUPPLY_PROP_PRESENT,
195 POWER_SUPPLY_PROP_VOLTAGE_NOW,
196 POWER_SUPPLY_PROP_TEMP,
197 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
198};
199
6d2cea4f 200static int rx51_battery_probe(struct platform_device *pdev)
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201{
202 struct rx51_device_info *di;
203 int ret;
204
205 di = kzalloc(sizeof(*di), GFP_KERNEL);
206 if (!di)
207 return -ENOMEM;
208
209 platform_set_drvdata(pdev, di);
210
211 di->bat.name = dev_name(&pdev->dev);
212 di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
213 di->bat.properties = rx51_battery_props;
214 di->bat.num_properties = ARRAY_SIZE(rx51_battery_props);
215 di->bat.get_property = rx51_battery_get_property;
216
217 ret = power_supply_register(di->dev, &di->bat);
218 if (ret) {
219 platform_set_drvdata(pdev, NULL);
220 kfree(di);
221 return ret;
222 }
223
224 return 0;
225}
226
6d2cea4f 227static int rx51_battery_remove(struct platform_device *pdev)
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228{
229 struct rx51_device_info *di = platform_get_drvdata(pdev);
230
231 power_supply_unregister(&di->bat);
232 platform_set_drvdata(pdev, NULL);
233 kfree(di);
234
235 return 0;
236}
237
238static struct platform_driver rx51_battery_driver = {
239 .probe = rx51_battery_probe,
6d2cea4f 240 .remove = rx51_battery_remove,
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241 .driver = {
242 .name = "rx51-battery",
243 .owner = THIS_MODULE,
244 },
245};
246module_platform_driver(rx51_battery_driver);
247
248MODULE_ALIAS("platform:rx51-battery");
249MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
250MODULE_DESCRIPTION("Nokia RX-51 battery driver");
251MODULE_LICENSE("GPL");