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Pali Rohár04930ba2012-10-31 10:48:40 +01001/*
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>
Sebastian Reichel57da5e82014-03-01 21:22:44 +010027#include <linux/iio/consumer.h>
28#include <linux/of.h>
Marek Belisko8e2747f2013-08-22 00:45:10 +020029
Pali Rohár04930ba2012-10-31 10:48:40 +010030struct rx51_device_info {
31 struct device *dev;
32 struct power_supply bat;
Sebastian Reichel57da5e82014-03-01 21:22:44 +010033 struct iio_channel *channel_temp;
34 struct iio_channel *channel_bsi;
35 struct iio_channel *channel_vbat;
Pali Rohár04930ba2012-10-31 10:48:40 +010036};
37
38/*
39 * Read ADCIN channel value, code copied from maemo kernel
40 */
Sebastian Reichel57da5e82014-03-01 21:22:44 +010041static int rx51_battery_read_adc(struct iio_channel *channel)
Pali Rohár04930ba2012-10-31 10:48:40 +010042{
Sebastian Reichel57da5e82014-03-01 21:22:44 +010043 int val, err;
44 err = iio_read_channel_average_raw(channel, &val);
45 if (err < 0)
46 return err;
47 return val;
Pali Rohár04930ba2012-10-31 10:48:40 +010048}
49
50/*
51 * Read ADCIN channel 12 (voltage) and convert RAW value to micro voltage
52 * This conversion formula was extracted from maemo program bsi-read
53 */
54static int rx51_battery_read_voltage(struct rx51_device_info *di)
55{
Sebastian Reichel57da5e82014-03-01 21:22:44 +010056 int voltage = rx51_battery_read_adc(di->channel_vbat);
Pali Rohár04930ba2012-10-31 10:48:40 +010057
Sebastian Reichel57da5e82014-03-01 21:22:44 +010058 if (voltage < 0) {
59 dev_err(di->dev, "Could not read ADC: %d\n", voltage);
Pali Rohár04930ba2012-10-31 10:48:40 +010060 return voltage;
Sebastian Reichel57da5e82014-03-01 21:22:44 +010061 }
Pali Rohár04930ba2012-10-31 10:48:40 +010062
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;
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100110 int raw = rx51_battery_read_adc(di->channel_temp);
111
112 if (raw < 0)
113 dev_err(di->dev, "Could not read ADC: %d\n", raw);
Pali Rohár04930ba2012-10-31 10:48:40 +0100114
115 /* Zero and negative values are undefined */
116 if (raw <= 0)
117 return INT_MAX;
118
119 /* ADC channels are 10 bit, higher value are undefined */
120 if (raw >= (1 << 10))
121 return INT_MIN;
122
123 /* First check for temperature in first direct table */
124 if (raw < ARRAY_SIZE(rx51_temp_table1))
Pali Rohár59584852013-03-28 17:42:23 +0100125 return rx51_temp_table1[raw] * 10;
Pali Rohár04930ba2012-10-31 10:48:40 +0100126
127 /* Binary search RAW value in second inverse table */
128 while (max - min > 1) {
129 int mid = (max + min) / 2;
130 if (rx51_temp_table2[mid] <= raw)
131 min = mid;
132 else if (rx51_temp_table2[mid] > raw)
133 max = mid;
134 if (rx51_temp_table2[mid] == raw)
135 break;
136 }
137
Pali Rohár59584852013-03-28 17:42:23 +0100138 return (rx51_temp_table2_first - min) * 10;
Pali Rohár04930ba2012-10-31 10:48:40 +0100139}
140
141/*
142 * Read ADCIN channel 4 (BSI) and convert RAW value to micro Ah
143 * This conversion formula was extracted from maemo program bsi-read
144 */
145static int rx51_battery_read_capacity(struct rx51_device_info *di)
146{
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100147 int capacity = rx51_battery_read_adc(di->channel_bsi);
Pali Rohár04930ba2012-10-31 10:48:40 +0100148
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100149 if (capacity < 0) {
150 dev_err(di->dev, "Could not read ADC: %d\n", capacity);
Pali Rohár04930ba2012-10-31 10:48:40 +0100151 return capacity;
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100152 }
Pali Rohár04930ba2012-10-31 10:48:40 +0100153
154 return 1280 * (1200 * capacity)/(1024 - capacity);
155}
156
157/*
158 * Return power_supply property
159 */
160static int rx51_battery_get_property(struct power_supply *psy,
161 enum power_supply_property psp,
162 union power_supply_propval *val)
163{
164 struct rx51_device_info *di = container_of((psy),
165 struct rx51_device_info, bat);
166
167 switch (psp) {
168 case POWER_SUPPLY_PROP_TECHNOLOGY:
169 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
170 break;
171 case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
172 val->intval = 4200000;
173 break;
174 case POWER_SUPPLY_PROP_PRESENT:
175 val->intval = rx51_battery_read_voltage(di) ? 1 : 0;
176 break;
177 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
178 val->intval = rx51_battery_read_voltage(di);
179 break;
180 case POWER_SUPPLY_PROP_TEMP:
181 val->intval = rx51_battery_read_temperature(di);
182 break;
183 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
184 val->intval = rx51_battery_read_capacity(di);
185 break;
186 default:
187 return -EINVAL;
188 }
189
190 if (val->intval == INT_MAX || val->intval == INT_MIN)
191 return -EINVAL;
192
193 return 0;
194}
195
196static enum power_supply_property rx51_battery_props[] = {
197 POWER_SUPPLY_PROP_TECHNOLOGY,
198 POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
199 POWER_SUPPLY_PROP_PRESENT,
200 POWER_SUPPLY_PROP_VOLTAGE_NOW,
201 POWER_SUPPLY_PROP_TEMP,
202 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
203};
204
Greg Kroah-Hartman6d2cea42012-12-21 15:04:54 -0800205static int rx51_battery_probe(struct platform_device *pdev)
Pali Rohár04930ba2012-10-31 10:48:40 +0100206{
207 struct rx51_device_info *di;
208 int ret;
209
Jingoo Hanb852ac52013-03-11 15:35:58 +0900210 di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
Pali Rohár04930ba2012-10-31 10:48:40 +0100211 if (!di)
212 return -ENOMEM;
213
214 platform_set_drvdata(pdev, di);
215
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100216 di->dev = &pdev->dev;
Pali Rohár04930ba2012-10-31 10:48:40 +0100217 di->bat.name = dev_name(&pdev->dev);
218 di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
219 di->bat.properties = rx51_battery_props;
220 di->bat.num_properties = ARRAY_SIZE(rx51_battery_props);
221 di->bat.get_property = rx51_battery_get_property;
222
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100223 di->channel_temp = iio_channel_get(di->dev, "temp");
224 if (IS_ERR(di->channel_temp)) {
225 ret = PTR_ERR(di->channel_temp);
226 goto error;
227 }
228
229 di->channel_bsi = iio_channel_get(di->dev, "bsi");
230 if (IS_ERR(di->channel_bsi)) {
231 ret = PTR_ERR(di->channel_bsi);
232 goto error_channel_temp;
233 }
234
235 di->channel_vbat = iio_channel_get(di->dev, "vbat");
236 if (IS_ERR(di->channel_vbat)) {
237 ret = PTR_ERR(di->channel_vbat);
238 goto error_channel_bsi;
239 }
240
Pali Rohár04930ba2012-10-31 10:48:40 +0100241 ret = power_supply_register(di->dev, &di->bat);
Jingoo Hanf70d7392013-05-06 13:23:45 +0900242 if (ret)
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100243 goto error_channel_vbat;
Pali Rohár04930ba2012-10-31 10:48:40 +0100244
245 return 0;
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100246
247error_channel_vbat:
248 iio_channel_release(di->channel_vbat);
249error_channel_bsi:
250 iio_channel_release(di->channel_bsi);
251error_channel_temp:
252 iio_channel_release(di->channel_temp);
253error:
254
255 return ret;
Pali Rohár04930ba2012-10-31 10:48:40 +0100256}
257
Greg Kroah-Hartman6d2cea42012-12-21 15:04:54 -0800258static int rx51_battery_remove(struct platform_device *pdev)
Pali Rohár04930ba2012-10-31 10:48:40 +0100259{
260 struct rx51_device_info *di = platform_get_drvdata(pdev);
261
262 power_supply_unregister(&di->bat);
Pali Rohár04930ba2012-10-31 10:48:40 +0100263
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100264 iio_channel_release(di->channel_vbat);
265 iio_channel_release(di->channel_bsi);
266 iio_channel_release(di->channel_temp);
267
Pali Rohár04930ba2012-10-31 10:48:40 +0100268 return 0;
269}
270
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100271#ifdef CONFIG_OF
272static const struct of_device_id n900_battery_of_match[] = {
273 {.compatible = "nokia,n900-battery", },
274 { },
275};
276MODULE_DEVICE_TABLE(of, n900_battery_of_match);
277#endif
278
Pali Rohár04930ba2012-10-31 10:48:40 +0100279static struct platform_driver rx51_battery_driver = {
280 .probe = rx51_battery_probe,
Greg Kroah-Hartman6d2cea42012-12-21 15:04:54 -0800281 .remove = rx51_battery_remove,
Pali Rohár04930ba2012-10-31 10:48:40 +0100282 .driver = {
283 .name = "rx51-battery",
Sebastian Reichel57da5e82014-03-01 21:22:44 +0100284 .of_match_table = of_match_ptr(n900_battery_of_match),
Pali Rohár04930ba2012-10-31 10:48:40 +0100285 },
286};
287module_platform_driver(rx51_battery_driver);
288
289MODULE_ALIAS("platform:rx51-battery");
290MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
291MODULE_DESCRIPTION("Nokia RX-51 battery driver");
292MODULE_LICENSE("GPL");