| /* |
| * 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> |
| |
| 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 = 1 << 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(12); |
| |
| 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(0); |
| |
| /* 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(4); |
| |
| 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"); |