linux/drivers/power/rx51_battery.c
Pali Rohár 8059c1c6be power: rx51_battery: Fix reporting correct values
Tell twl4030_madc_conversion that this driver needs raw values.
Driver twl4030_madc has some hardcoded values and conversation
functions which are incorrect for Nokia RX-51 board. This driver
rx51_battery expects raw values which convert itself.

This patch fixing values reported by power supply interface.
Before this patch driver reported always incorrect values on
3.8 kernel (sometimes design capacity was negative).

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2013-04-08 16:36:27 +02:00

253 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;
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] * 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");