power: add driver for battery reading on iPaq h3xxx

This adds a driver for reading the battery status of the
battery connected to the Atmel microcontroller on the
iPAQ h3xxx series.

Based on a driver from handhelds.org 2.6.21 kernel, written
by Alessandro GARDICH.

Signed-off-by: Dmitry Artamonow <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/Kconfig

···
 	  Say Y to enable support for the battery on the Sharp Zaurus
 	  SL-5500 (collie) models.
 
+config BATTERY_IPAQ_MICRO
+	tristate "iPAQ Atmel Micro ASIC battery driver"
+	depends on MFD_IPAQ_MICRO
+	help
+	  Choose this option if you want to monitor battery status on
+	  Compaq/HP iPAQ h3100 and h3600.
+
 config BATTERY_WM97XX
 	bool "WM97xx generic battery driver"
 	depends on TOUCHSCREEN_WM97XX=y

drivers/power/Makefile

···
 obj-$(CONFIG_BATTERY_OLPC)	+= olpc_battery.o
 obj-$(CONFIG_BATTERY_TOSA)	+= tosa_battery.o
 obj-$(CONFIG_BATTERY_COLLIE)	+= collie_battery.o
+obj-$(CONFIG_BATTERY_IPAQ_MICRO) += ipaq_micro_battery.o
 obj-$(CONFIG_BATTERY_WM97XX)	+= wm97xx_battery.o
 obj-$(CONFIG_BATTERY_SBS)	+= sbs-battery.o
 obj-$(CONFIG_BATTERY_BQ27x00)	+= bq27x00_battery.o

drivers/power/ipaq_micro_battery.c

···
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * h3xxx atmel micro companion support, battery subdevice
+ * based on previous kernel 2.4 version
+ * Author : Alessandro Gardich <[e-mail]>
+ * Author : Linus Walleij <[e-mail]>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/ipaq-micro.h>
+#include <linux/power_supply.h>
+#include <linux/workqueue.h>
+
+#define BATT_PERIOD 100000 /* 100 seconds in milliseconds */
+
+#define MICRO_BATT_CHEM_ALKALINE	0x01
+#define MICRO_BATT_CHEM_NICD		0x02
+#define MICRO_BATT_CHEM_NIMH		0x03
+#define MICRO_BATT_CHEM_LION		0x04
+#define MICRO_BATT_CHEM_LIPOLY		0x05
+#define MICRO_BATT_CHEM_NOT_INSTALLED	0x06
+#define MICRO_BATT_CHEM_UNKNOWN		0xff
+
+#define MICRO_BATT_STATUS_HIGH		0x01
+#define MICRO_BATT_STATUS_LOW		0x02
+#define MICRO_BATT_STATUS_CRITICAL	0x04
+#define MICRO_BATT_STATUS_CHARGING	0x08
+#define MICRO_BATT_STATUS_CHARGEMAIN	0x10
+#define MICRO_BATT_STATUS_DEAD		0x20 /* Battery will not charge */
+#define MICRO_BATT_STATUS_NOTINSTALLED	0x20 /* For expansion pack batteries */
+#define MICRO_BATT_STATUS_FULL		0x40 /* Battery fully charged */
+#define MICRO_BATT_STATUS_NOBATTERY	0x80
+#define MICRO_BATT_STATUS_UNKNOWN	0xff
+
+struct micro_battery {
+	struct ipaq_micro *micro;
+	struct workqueue_struct *wq;
+	struct delayed_work update;
+	u8 ac;
+	u8 chemistry;
+	unsigned int voltage;
+	u16 temperature;
+	u8 flag;
+};
+
+static void micro_battery_work(struct work_struct *work)
+{
+	struct micro_battery *mb = container_of(work,
+				struct micro_battery, update.work);
+	struct ipaq_micro_msg msg_battery = {
+		.id = MSG_BATTERY,
+	};
+	struct ipaq_micro_msg msg_sensor = {
+		.id = MSG_THERMAL_SENSOR,
+	};
+
+	/* First send battery message */
+	ipaq_micro_tx_msg_sync(mb->micro, &msg_battery);
+	if (msg_battery.rx_len < 4)
+		pr_info("ERROR");
+
+	/*
+	 * Returned message format:
+	 * byte 0:   0x00 = Not plugged in
+	 *           0x01 = AC adapter plugged in
+	 * byte 1:   chemistry
+	 * byte 2:   voltage LSB
+	 * byte 3:   voltage MSB
+	 * byte 4:   flags
+	 * byte 5-9: same for battery 2
+	 */
+	mb->ac = msg_battery.rx_data[0];
+	mb->chemistry = msg_battery.rx_data[1];
+	mb->voltage = ((((unsigned short)msg_battery.rx_data[3] << 8) +
+			msg_battery.rx_data[2]) * 5000L) * 1000 / 1024;
+	mb->flag = msg_battery.rx_data[4];
+
+	if (msg_battery.rx_len == 9)
+		pr_debug("second battery ignored\n");
+
+	/* Then read the sensor */
+	ipaq_micro_tx_msg_sync(mb->micro, &msg_sensor);
+	mb->temperature = msg_sensor.rx_data[1] << 8 | msg_sensor.rx_data[0];
+
+	queue_delayed_work(mb->wq, &mb->update, msecs_to_jiffies(BATT_PERIOD));
+}
+
+static int get_capacity(struct power_supply *b)
+{
+	struct micro_battery *mb = dev_get_drvdata(b->dev->parent);
+
+	switch (mb->flag & 0x07) {
+	case MICRO_BATT_STATUS_HIGH:
+		return 100;
+		break;
+	case MICRO_BATT_STATUS_LOW:
+		return 50;
+		break;
+	case MICRO_BATT_STATUS_CRITICAL:
+		return 5;
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static int get_status(struct power_supply *b)
+{
+	struct micro_battery *mb = dev_get_drvdata(b->dev->parent);
+
+	if (mb->flag == MICRO_BATT_STATUS_UNKNOWN)
+		return POWER_SUPPLY_STATUS_UNKNOWN;
+
+	if (mb->flag & MICRO_BATT_STATUS_FULL)
+		return POWER_SUPPLY_STATUS_FULL;
+
+	if ((mb->flag & MICRO_BATT_STATUS_CHARGING) ||
+		(mb->flag & MICRO_BATT_STATUS_CHARGEMAIN))
+		return POWER_SUPPLY_STATUS_CHARGING;
+
+	return POWER_SUPPLY_STATUS_DISCHARGING;
+}
+
+static int micro_batt_get_property(struct power_supply *b,
+					enum power_supply_property psp,
+					union power_supply_propval *val)
+{
+	struct micro_battery *mb = dev_get_drvdata(b->dev->parent);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		switch (mb->chemistry) {
+		case MICRO_BATT_CHEM_NICD:
+			val->intval = POWER_SUPPLY_TECHNOLOGY_NiCd;
+			break;
+		case MICRO_BATT_CHEM_NIMH:
+			val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
+			break;
+		case MICRO_BATT_CHEM_LION:
+			val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
+			break;
+		case MICRO_BATT_CHEM_LIPOLY:
+			val->intval = POWER_SUPPLY_TECHNOLOGY_LIPO;
+			break;
+		default:
+			val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
+			break;
+		};
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = get_status(b);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = 4700000;
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		val->intval = get_capacity(b);
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		val->intval = mb->temperature;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = mb->voltage;
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	return 0;
+}
+
+static int micro_ac_get_property(struct power_supply *b,
+				 enum power_supply_property psp,
+				 union power_supply_propval *val)
+{
+	struct micro_battery *mb = dev_get_drvdata(b->dev->parent);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = mb->ac;
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	return 0;
+}
+
+static enum power_supply_property micro_batt_power_props[] = {
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+};
+
+static struct power_supply micro_batt_power = {
+	.name			= "main-battery",
+	.type			= POWER_SUPPLY_TYPE_BATTERY,
+	.properties		= micro_batt_power_props,
+	.num_properties		= ARRAY_SIZE(micro_batt_power_props),
+	.get_property		= micro_batt_get_property,
+	.use_for_apm		= 1,
+};
+
+static enum power_supply_property micro_ac_power_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+static struct power_supply micro_ac_power = {
+	.name			= "ac",
+	.type			= POWER_SUPPLY_TYPE_MAINS,
+	.properties		= micro_ac_power_props,
+	.num_properties		= ARRAY_SIZE(micro_ac_power_props),
+	.get_property		= micro_ac_get_property,
+};
+
+static int micro_batt_probe(struct platform_device *pdev)
+{
+	struct micro_battery *mb;
+
+	mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL);
+	if (!mb)
+		return -ENOMEM;
+
+	mb->micro = dev_get_drvdata(pdev->dev.parent);
+	mb->wq = create_singlethread_workqueue("ipaq-battery-wq");
+	INIT_DELAYED_WORK(&mb->update, micro_battery_work);
+	platform_set_drvdata(pdev, mb);
+	queue_delayed_work(mb->wq, &mb->update, 1);
+	power_supply_register(&pdev->dev, &micro_batt_power);
+	power_supply_register(&pdev->dev, &micro_ac_power);
+
+	dev_info(&pdev->dev, "iPAQ micro battery driver\n");
+	return 0;
+}
+
+static int micro_batt_remove(struct platform_device *pdev)
+
+{
+	struct micro_battery *mb = platform_get_drvdata(pdev);
+
+	power_supply_unregister(&micro_ac_power);
+	power_supply_unregister(&micro_batt_power);
+	cancel_delayed_work_sync(&mb->update);
+
+	return 0;
+}
+
+static int micro_batt_suspend(struct device *dev)
+{
+	struct micro_battery *mb = dev_get_drvdata(dev);
+
+	cancel_delayed_work_sync(&mb->update);
+	return 0;
+}
+
+static int micro_batt_resume(struct device *dev)
+{
+	struct micro_battery *mb = dev_get_drvdata(dev);
+
+	queue_delayed_work(mb->wq, &mb->update, msecs_to_jiffies(BATT_PERIOD));
+	return 0;
+}
+
+static const struct dev_pm_ops micro_batt_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(micro_batt_suspend, micro_batt_resume)
+};
+
+struct platform_driver micro_batt_device_driver = {
+	.driver		= {
+		.name	= "ipaq-micro-battery",
+		.pm	= &micro_batt_dev_pm_ops,
+	},
+	.probe		= micro_batt_probe,
+	.remove		= micro_batt_remove,
+};
+module_platform_driver(micro_batt_device_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("driver for iPAQ Atmel micro battery");
+MODULE_ALIAS("platform:battery-ipaq-micro");