252 lines
6.6 KiB
C
252 lines
6.6 KiB
C
/*
|
|
* 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;
|
|
|
|
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] * 100;
|
|
|
|
/* 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) * 100;
|
|
}
|
|
|
|
/*
|
|
* 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 = kzalloc(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) {
|
|
platform_set_drvdata(pdev, NULL);
|
|
kfree(di);
|
|
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);
|
|
platform_set_drvdata(pdev, NULL);
|
|
kfree(di);
|
|
|
|
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");
|