[PATCH v2] New Nokia RX-51 power supply battery driver

From: Pali Rohár
Date: Wed Oct 31 2012 - 05:48:45 EST

Hello, I fixed style issues and added it to Makefile and Kconfig.

power_supply: Add Nokia RX-51 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: Pali RohÃr <pali.rohar@xxxxxxxxx>

--- /dev/null
+++ linux/drivers/power/rx51_battery.c
@@ -0,0 +1,251 @@
+/*
+ * rx51_battery.c - Nokia RX-51 battery driver
+ * Copyright (C) 2012 Pali RohÃr <pali.rohar@xxxxxxxxx>
+ *
+ * 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 RohÃr <pali.rohar@xxxxxxxxx>");
+MODULE_DESCRIPTION("Nokia RX-51 battery driver");
+MODULE_LICENSE("GPL");
--- linux/drivers/power/Kconfig
+++ linux/drivers/power/Kconfig
@@ -245,6 +245,12 @@ config BATTERY_INTEL_MID
Say Y here to enable the battery driver on Intel MID
platforms.

+config BATTERY_RX51
+ tristate "Nokia RX-51 battery driver"
+ depends on TWL4030_MADC
+ help
+ Say Y here to enable support for battery information on Nokia RX-51.
+
config CHARGER_ISP1704
tristate "ISP1704 USB Charger Detection"
depends on USB_OTG_UTILS
--- linux/drivers/power/Makefile
+++ linux/drivers/power/Makefile
@@ -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

--
Pali RohÃr
pali.rohar@xxxxxxxxx

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