---
 arch/arm/mach-omap2/board-n8x0.c |   13 +
 drivers/cbus/Kconfig             |   12 +
 drivers/cbus/Makefile            |    3 
 drivers/cbus/lipocharge.c        |   63 ++++++
 drivers/cbus/lipocharge.h        |   50 ++++
 drivers/cbus/n810bm_main.c       |  397 +++++++++++++++++++++++++++++++++++++++
 drivers/cbus/retu.c              |    4 
 drivers/cbus/retu.h              |    3 
 drivers/cbus/tahvo.h             |    6 
 9 files changed, 548 insertions(+), 3 deletions(-)

--- linux-2.6.36-rc7.orig/drivers/cbus/Kconfig
+++ linux-2.6.36-rc7/drivers/cbus/Kconfig
@@ -94,4 +94,16 @@ config CBUS_RETU_HEADSET
 	  to Retu/Vilma. Detection state and events are exposed through
 	  sysfs.
 
+config N810BM
+	depends on CBUS_RETU && CBUS_TAHVO
+	tristate "Nokia n810 battery management"
+	---help---
+	  Nokia n810 device battery management.
+
+	  WARNING: This driver is based on reverse engineered information.
+	  It is possibly dangerous to use this software.
+	  Use this software at your own risk!
+
+	  If unsure, say N.
+
 endmenu
--- linux-2.6.36-rc7.orig/drivers/cbus/Makefile
+++ linux-2.6.36-rc7/drivers/cbus/Makefile
@@ -12,3 +12,6 @@ obj-$(CONFIG_CBUS_RETU_WDT)	+= retu-wdt.
 obj-$(CONFIG_CBUS_TAHVO_USER)	+= tahvo-user.o
 obj-$(CONFIG_CBUS_RETU_USER)	+= retu-user.o
 obj-$(CONFIG_CBUS_RETU_HEADSET)	+= retu-headset.o
+n810bm-y			+= n810bm_main.o
+n810bm-y			+= lipocharge.o
+obj-$(CONFIG_N810BM)		+= n810bm.o
--- /dev/null
+++ linux-2.6.36-rc7/drivers/cbus/n810bm_main.c
@@ -0,0 +1,397 @@
+/*
+ *   Nokia n810 battery management
+ *
+ *   WARNING: This driver is based on reverse engineered information.
+ *            It is possibly dangerous to use this software.
+ *            Use this software at your own risk!
+ *
+ *   Copyright (c) 2010 Michael Buesch <mb@bu3sch.de>
+ *
+ *   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.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/reboot.h>
+
+#include "retu.h"
+#include "tahvo.h"
+#include "lipocharge.h"
+
+
+#define N810BM_CHECK_INTERVAL		(HZ * 5)
+#define N810BM_MIN_VOLTAGE_THRES	3300 /* Absolute minimum voltage threshold */
+
+
+/* Battery related retu ADC channels */
+#define RETU_ADC_BSI		0x01 /* Battery Size Indicator */
+#define RETU_ADC_BATTVOLT	0x08 /* Battery voltage measurement */
+
+/* RETU_ADC_BSI
+ * The battery size indicator ADC measures the resistance between
+ * the battery BSI pin and ground. This is used to detect the battery
+ * capacity, as the BSI resistor is related to capacity.
+ *
+ * Manually measured lookup table.
+ * Hard to measure, thus not very accurate.
+ *
+ * Resistance  |  ADC value
+ * ========================
+ * 120k        |  0x3AC
+ * 110k        |  0x37C
+ * 100k        |  0x351
+ *  90k        |  0x329
+ */
+
+/* RETU_ADC_BATTVOLT
+ * Manually measured lookup table.
+ * Hard to measure, thus not very accurate.
+ *
+ * Voltage  |  ADC value
+ * =====================
+ * 2.80V    |  0x037
+ * 2.90V    |  0x05E
+ * 3.00V    |  0x090
+ * 3.10V    |  0x0A4
+ * 3.20V    |  0x0CC
+ * 3.30V    |  0x0EF
+ * 3.40V    |  0x115
+ * 3.50V    |  0x136
+ * 3.60V    |  0x15C
+ * 3.70V    |  0x187
+ * 3.80V    |  0x1A5
+ * 3.90V    |  0x1C9
+ * 4.00V    |  0x1ED
+ * 4.10V    |  0x212
+ * 4.20V    |  0x236
+ */
+
+
+enum n810bm_capacity {
+	N810BM_CAP_UNKNOWN	= 0,
+	N810BM_CAP_1500MAH	= 1500,	/* 1500 mAh battery */
+};
+
+struct n810bm {
+	struct platform_device *pdev;
+
+	enum n810bm_capacity capacity;
+	struct timer_list check_timer;
+
+	struct lipocharge *charger;
+
+	spinlock_t lock;
+};
+
+
+static NORET_TYPE void n810bm_emergency(struct n810bm *bm, const char *message) ATTRIB_NORET;
+static void n810bm_emergency(struct n810bm *bm, const char *message)
+{
+	printk(KERN_EMERG "n810 battery management fatal fault: %s\n", message);
+	/* Force a hard shutdown. */
+	machine_power_off();
+	panic("n810bm: Failed to halt machine in emergency state\n");
+}
+
+#if 0
+static u16 retu_read(struct n810bm *bm, unsigned int reg)
+{
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&retu_lock, flags);
+	ret = retu_read_reg(reg);
+	spin_unlock_irqrestore(&retu_lock, flags);
+	if (ret < 0 || ret > 0xFFFF)
+		n810bm_emergency(bm, "retu_read");
+
+	return ret;
+}
+#endif
+
+static void retu_maskset(struct n810bm *bm, unsigned int reg, u16 mask, u16 set)
+{
+	int ret;
+	unsigned long flags;
+	u16 value;
+
+	spin_lock_irqsave(&retu_lock, flags);
+	if (~mask) {
+		ret = retu_read_reg(reg);
+		if (ret < 0 || ret > 0xFFFF)
+			goto fatal_unlock;
+		value = ret;
+	} else
+		value = 0;
+	value &= ~mask;
+	value |= set;
+	ret = retu_write_reg(reg, value);
+	if (ret)
+		goto fatal_unlock;
+	spin_unlock_irqrestore(&retu_lock, flags);
+
+	return;
+
+fatal_unlock:
+	spin_unlock_irqrestore(&retu_lock, flags);
+	n810bm_emergency(bm, "retu_maskset");
+}
+
+static inline void retu_write(struct n810bm *bm, unsigned int reg, u16 value)
+{
+	return retu_maskset(bm, reg, 0xFFFF, value);
+}
+
+static int retu_adc_average(struct n810bm *bm, unsigned int chan,
+			    unsigned int nr_passes)
+{
+	unsigned int i, value = 0;
+	int ret;
+
+	if (WARN_ON(!nr_passes))
+		return 0;
+	for (i = 0; i < nr_passes; i++) {
+		ret = retu_read_adc(chan);
+		if (ret < 0)
+			return ret;
+		value += ret;
+	}
+	value /= nr_passes;
+
+	return value;
+}
+
+/* Measure the battery voltage. Returns the value in mV (or negative value on error). */
+static int n810bm_measure_batt_voltage(struct n810bm *bm)
+{
+	int adc;
+	unsigned int mv;
+	const unsigned int scale = 1000;
+
+	adc = retu_adc_average(bm, RETU_ADC_BATTVOLT, 5);
+	if (adc < 0)
+		return adc;
+	if (adc <= 0x37)
+		return 2800;
+	mv = 2800 + ((adc - 0x37) * (((4200 - 2800) * scale) / (0x236 - 0x37))) / scale;
+
+	return mv;
+}
+
+/* Read the battery capacity via BSI pin. */
+static enum n810bm_capacity n810bm_read_batt_capacity(struct n810bm *bm)
+{
+	int adc;
+	const unsigned int hyst = 20;
+
+	adc = retu_adc_average(bm, RETU_ADC_BSI, 5);
+	if (adc < 0) {
+		dev_err(&bm->pdev->dev, "Failed to read BSI ADC");
+		return N810BM_CAP_UNKNOWN;
+	}
+
+	if (adc >= 0x3B5 - hyst && adc <= 0x3B5 + hyst)
+		return N810BM_CAP_1500MAH;
+
+	dev_err(&bm->pdev->dev, "Capacity indicator 0x%X unknown", adc);
+
+	return N810BM_CAP_UNKNOWN;
+}
+
+/* Convert a battery voltage (in mV) to percentage. */
+static unsigned int n810bm_mvolt2percent(unsigned int mv)
+{
+	const unsigned int minv = 3700;
+	const unsigned int maxv = 4150;
+	unsigned int percent;
+
+	mv = clamp(mv, minv, maxv);
+	percent = (mv - minv) * 100 / (maxv - minv);
+
+	return percent;
+}
+
+static void n810bm_check_timer(unsigned long data)
+{
+	struct n810bm *bm = (struct n810bm *)data;
+	unsigned long flags;
+	int mv;
+
+	spin_lock_irqsave(&bm->lock, flags);
+
+	mv = n810bm_measure_batt_voltage(bm);
+	if (mv < 0)
+		n810bm_emergency(bm, "check timer: Failed to measure");
+	if (mv < N810BM_MIN_VOLTAGE_THRES)
+		n810bm_emergency(bm, "check timer: Minimum voltage threshold reached");
+
+	mod_timer(&bm->check_timer, round_jiffies(jiffies + N810BM_CHECK_INTERVAL));
+	spin_unlock_irqrestore(&bm->lock, flags);
+
+	return;
+}
+
+static void n810bm_adc_irq_handler(unsigned long data)
+{
+	struct n810bm *bm = (struct n810bm *)data;
+
+	retu_ack_irq(RETU_INT_ADCS);
+	//TODO
+printk("n810bm: ADC timer triggered\n");
+}
+
+static ssize_t n810bm_attr_charge_show(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct n810bm *bm = platform_get_drvdata(pdev);
+	int err = -ENODEV;
+	ssize_t count = 0;
+	int millivolt;
+
+	spin_lock_irq(&bm->lock);
+	millivolt = n810bm_measure_batt_voltage(bm);
+	if (millivolt >= 0) {
+		count = snprintf(buf, PAGE_SIZE, "%u\n",
+				 n810bm_mvolt2percent(millivolt));
+		err = 0;
+	}
+	spin_unlock_irq(&bm->lock);
+
+	return err ? err : count;
+}
+static DEVICE_ATTR(batt_charge, 0444, n810bm_attr_charge_show, NULL);
+
+static ssize_t n810bm_attr_capacity_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct n810bm *bm = platform_get_drvdata(pdev);
+	ssize_t count;
+
+	spin_lock_irq(&bm->lock);
+	count = snprintf(buf, PAGE_SIZE, "%u\n",
+			 (unsigned int)bm->capacity);
+	spin_unlock_irq(&bm->lock);
+
+	return count;
+}
+static DEVICE_ATTR(batt_capacity, 0444, n810bm_attr_capacity_show, NULL);
+
+static void n810bm_hw_exit(struct n810bm *bm)
+{
+	retu_write(bm, RETU_REG_ADCSCR, 0);
+}
+
+static int n810bm_hw_init(struct n810bm *bm)
+{
+	retu_write(bm, RETU_REG_ADCSCR, 0);
+
+	bm->capacity = n810bm_read_batt_capacity(bm);
+	if (bm->capacity == N810BM_CAP_UNKNOWN) {
+		dev_err(&bm->pdev->dev, "Unknown battery detected");
+		return -ENODEV;
+	}
+	dev_info(&bm->pdev->dev, "Detected %u mAh battery\n",
+		 (unsigned int)bm->capacity);
+
+	return 0;
+}
+
+static int __devinit n810bm_probe(struct platform_device *pdev)
+{
+	struct n810bm *bm;
+	int err;
+
+	bm = kzalloc(sizeof(*bm), GFP_KERNEL);
+	if (!bm)
+		return -ENOMEM;
+	bm->pdev = pdev;
+	platform_set_drvdata(pdev, bm);
+	spin_lock_init(&bm->lock);
+	setup_timer(&bm->check_timer, n810bm_check_timer, (unsigned long)bm);
+
+	err = n810bm_hw_init(bm);
+	if (err)
+		goto err_free;
+	err = device_create_file(&pdev->dev, &dev_attr_batt_charge);
+	if (err)
+		goto err_exit;
+	err = device_create_file(&pdev->dev, &dev_attr_batt_capacity);
+	if (err)
+		goto err_rem_charge;
+	err = retu_request_irq(RETU_INT_ADCS, n810bm_adc_irq_handler,
+			       (unsigned long)bm, "n810bm");
+	if (err)
+		goto err_rem_capa;
+
+	mod_timer(&bm->check_timer, round_jiffies(jiffies + N810BM_CHECK_INTERVAL));
+
+	dev_info(&pdev->dev, "Battery management initialized");
+
+	return 0;
+
+err_rem_capa:
+	device_remove_file(&pdev->dev, &dev_attr_batt_capacity);
+err_rem_charge:
+	device_remove_file(&pdev->dev, &dev_attr_batt_charge);
+err_exit:
+	n810bm_hw_exit(bm);
+err_free:
+	kfree(bm);
+	platform_set_drvdata(pdev, NULL);
+	return err;
+}
+
+static int __devexit n810bm_remove(struct platform_device *pdev)
+{
+	struct n810bm *bm = platform_get_drvdata(pdev);
+
+	retu_free_irq(RETU_INT_ADCS);
+	del_timer_sync(&bm->check_timer);
+	device_remove_file(&pdev->dev, &dev_attr_batt_capacity);
+	device_remove_file(&pdev->dev, &dev_attr_batt_charge);
+	n810bm_hw_exit(bm);
+
+	kfree(bm);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver n810bm_driver = {
+	.remove		= __devexit_p(n810bm_remove),
+	.driver		= {
+		.name	= "n810bm",
+	}
+};
+
+static int __init n810bm_modinit(void)
+{
+	return platform_driver_probe(&n810bm_driver, n810bm_probe);
+}
+module_init(n810bm_modinit);
+
+static void __exit n810bm_modexit(void)
+{
+	platform_driver_unregister(&n810bm_driver);
+}
+module_exit(n810bm_modexit);
+
+MODULE_DESCRIPTION("Nokia n810 battery management");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michael Buesch");
--- linux-2.6.36-rc7.orig/drivers/cbus/retu.c
+++ linux-2.6.36-rc7/drivers/cbus/retu.c
@@ -85,10 +85,10 @@ int retu_read_reg(int reg)
  *
  * This function writes a value to the specified register
  */
-void retu_write_reg(int reg, u16 val)
+int retu_write_reg(int reg, u16 val)
 {
 	BUG_ON(!retu_initialized);
-	cbus_write_reg(cbus_host, RETU_ID, reg, val);
+	return cbus_write_reg(cbus_host, RETU_ID, reg, val);
 }
 
 void retu_set_clear_reg_bits(int reg, u16 set, u16 clear)
--- linux-2.6.36-rc7.orig/drivers/cbus/retu.h
+++ linux-2.6.36-rc7/drivers/cbus/retu.h
@@ -39,6 +39,7 @@
 #define RETU_REG_CC2		0x0e	/* Common control register 2 */
 #define RETU_REG_CTRL_CLR	0x0f	/* Regulator clear register */
 #define RETU_REG_CTRL_SET	0x10	/* Regulator set register */
+#define RETU_REG_UNK1		0x14	/* 0x1000 is set when charger is plugged in */
 #define RETU_REG_STATUS		0x16	/* Status register */
 #define RETU_REG_WATCHDOG	0x17	/* Watchdog register */
 #define RETU_REG_AUDTXR		0x18	/* Audio Codec Tx register */
@@ -58,7 +59,7 @@
 #define	MAX_RETU_IRQ_HANDLERS	16
 
 int retu_read_reg(int reg);
-void retu_write_reg(int reg, u16 val);
+int retu_write_reg(int reg, u16 val);
 void retu_set_clear_reg_bits(int reg, u16 set, u16 clear);
 int retu_read_adc(int channel);
 int retu_request_irq(int id, void *irq_handler, unsigned long arg, char *name);
--- linux-2.6.36-rc7.orig/arch/arm/mach-omap2/board-n8x0.c
+++ linux-2.6.36-rc7/arch/arm/mach-omap2/board-n8x0.c
@@ -920,6 +920,17 @@ static int __init n810_tlv320aic3x_regis
 }
 arch_initcall(n810_tlv320aic3x_register);
 
+static struct platform_device n810_bm_device = {
+	.name		= "n810bm",
+	.id		= -1,
+};
+
+static void __init n810_bm_init(void)
+{
+	if (platform_device_register(&n810_bm_device))
+		BUG();
+}
+
 static void __init n8x0_init_machine(void)
 {
 	omap2420_mux_init(board_mux, OMAP_PACKAGE_ZAC);
@@ -947,6 +958,8 @@ static void __init n8x0_init_machine(voi
 	n8x0_onenand_init();
 	n8x0_mmc_init();
 	n8x0_usb_init();
+
+	n810_bm_init();
 }
 
 MACHINE_START(NOKIA_N800, "Nokia N800")
--- /dev/null
+++ linux-2.6.36-rc7/drivers/cbus/lipocharge.c
@@ -0,0 +1,63 @@
+/*
+ *   Generic LIPO battery charger
+ *
+ *   Copyright (c) 2010 Michael Buesch <mb@bu3sch.de>
+ *
+ *   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.
+ */
+
+#include "lipocharge.h"
+
+#include <linux/slab.h>
+
+
+static void lipocharge_timer(unsigned long data)
+{
+	struct lipocharge *c = (struct lipocharge *)data;
+
+	spin_lock(&c->lock);
+	//TODO
+	spin_unlock(&c->lock);
+}
+
+struct lipocharge * lipocharge_alloc(gfp_t gfp)
+{
+	struct lipocharge *c;
+
+	c = kzalloc(sizeof(*c), gfp);
+	if (!c)
+		return NULL;
+	spin_lock_init(&c->lock);
+	setup_timer(&c->timer, lipocharge_timer, (unsigned long)c);
+
+	return c;
+}
+
+void lipocharge_free(struct lipocharge *c)
+{
+	kfree(c);
+}
+
+int lipocharge_start(struct lipocharge *c)
+{
+	if (!c->set_current || !c->get_voltage ||
+	    !c->finished || !c->emergency)
+		return -EINVAL;
+	if (!c->top_voltage || c->top_voltage > 4200)
+		return -EINVAL;
+	//TODO
+}
+
+void lipocharge_stop(struct lipocharge *c)
+{
+	del_timer_sync(&c->timer);
+	//TODO
+}
--- /dev/null
+++ linux-2.6.36-rc7/drivers/cbus/lipocharge.h
@@ -0,0 +1,50 @@
+#ifndef LIPOCHARGE_H_
+#define LIPOCHARGE_H_
+
+#include <linux/timer.h>
+#include <linux/spinlock.h>
+
+
+#define LIPORATE(a,b)	(((a) * 1000) + (b))
+#define LIPORATE_1C	LIPORATE(1,0)	/* 1C */
+#define LIPORATE_p8C	LIPORATE(0,8)	/* 0.8C */
+
+/** struct lipocharge - A generic LIPO charger
+ *
+ * @capacity: Battery capacity in mAh.
+ * @rate: Charge rate.
+ * @top_voltage: Fully charged voltage, in mV.
+ *
+ * @set_current: Set the charge current, in mA.
+ * @get_voltage: Get the battery voltage, in mV.
+ *
+ * @emergency: Something went wrong. Force shutdown.
+ *
+ * @priv: opaque pointer.
+ */
+struct lipocharge
+{
+	unsigned int capacity;
+	unsigned int rate;
+	unsigned int top_voltage;
+
+	int (*set_current)(struct lipocharge *c, unsigned int ma);
+	int (*get_voltage)(struct lipocharge *c, unsigned int *mv);
+
+	void (*finished)(struct lipocharge *c);
+	void (*emergency)(struct lipocharge *c);
+
+	void *priv;
+
+	/* internal */
+	spinlock_t lock;
+	struct timer_list timer;
+};
+
+struct lipocharge * lipocharge_alloc(gfp_t gfp);
+void lipocharge_free(struct lipocharge *c);
+
+int lipocharge_start(struct lipocharge *c);
+void lipocharge_stop(struct lipocharge *c);
+
+#endif /* LIPOCHARGE_H_ */
--- linux-2.6.36-rc7.orig/drivers/cbus/tahvo.h
+++ linux-2.6.36-rc7/drivers/cbus/tahvo.h
@@ -30,8 +30,14 @@
 #define TAHVO_REG_IDR		0x01	/* Interrupt ID */
 #define TAHVO_REG_IDSR		0x02	/* Interrupt status */
 #define TAHVO_REG_IMR		0x03	/* Interrupt mask */
+#define TAHVO_REG_CHGCURR	0x04	/* Charge current control (8-bit) */
 #define TAHVO_REG_LEDPWMR	0x05	/* LED PWM */
 #define TAHVO_REG_USBR		0x06	/* USB control */
+#define TAHVO_REG_CHGCTL	0x08	/* Charge control register */
+#define  TAHVO_REG_CHGCTL_EN	0x0001	/* Global charge enable */
+#define TAHVO_REG_CHGCTL2	0x0c	/* Charge control register 2 */
+#define TAHVO_REG_BATCURR	0x0d	/* Battery (dis)charge current (signed 16-bit) */
+
 #define TAHVO_REG_MAX		0x0d
 
 /* Interrupt sources */
