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Commit 04930baf authored by Pali Rohár's avatar Pali Rohár Committed by Anton Vorontsov
Browse files

power_supply: Add new Nokia RX-51 (N900) power supply battery driver 



This driver exporting battery design capacity, temperature and voltage for
battery in Nokia RX-51. This driver is needed for open source battery
management on Nokia RX-51 (N900).

Signed-off-by: default avatarPali Rohár <pali.rohar@gmail.com>
Signed-off-by: default avatarAnton Vorontsov <anton.vorontsov@linaro.org>
parent a879f19f

drivers/power/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -245,6 +245,13 @@ config BATTERY_INTEL_MID 
	  Say Y here to enable the battery driver on Intel MID

	  platforms.



config BATTERY_RX51

	tristate "Nokia RX-51 (N900) battery driver"

	depends on TWL4030_MADC

	help

	  Say Y here to enable support for battery information on Nokia

	  RX-51, also known as N900 tablet.



config CHARGER_ISP1704

	tristate "ISP1704 USB Charger Detection"

	depends on USB_OTG_UTILS

drivers/power/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ obj-$(CONFIG_CHARGER_88PM860X) += 88pm860x_charger.o 
obj-$(CONFIG_CHARGER_PCF50633)	+= pcf50633-charger.o

obj-$(CONFIG_BATTERY_JZ4740)	+= jz4740-battery.o

obj-$(CONFIG_BATTERY_INTEL_MID)	+= intel_mid_battery.o

obj-$(CONFIG_BATTERY_RX51)	+= rx51_battery.o

obj-$(CONFIG_AB8500_BM)		+= ab8500_charger.o ab8500_btemp.o ab8500_fg.o abx500_chargalg.o

obj-$(CONFIG_CHARGER_ISP1704)	+= isp1704_charger.o

obj-$(CONFIG_CHARGER_MAX8903)	+= max8903_charger.o

drivers/power/rx51_battery.c

0 → 100644
+251 −0
Original line number Diff line number Diff line 
/*

 * 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 __devinit 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 __devexit 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 = __devexit_p(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");