[BATTERY] pda_power platform driver

Common power driver for PDAs and phones with one or two external
power supplies (AC/USB) connected to main and backup batteries,
and optional builtin charger.

It's used to stop logic duplication through different embedded
devices. So, power supply *logic* is here. pda_power register
power supplies, and will take care about notifying batteries
about power changes through external power interface.

Currently, power consumption legal limits (including USB power
consumption) should be handled by platform code, inside set_charge
function.
Signed-off-by: Anton Vorontsov <cbou@mail.ru>
Signed-off-by: Roman Moravcik <roman.moravcik@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

drivers/power/Kconfig

@@ -14,4 +14,11 @@ config POWER_SUPPLY_DEBUG
 	  Say Y here to enable debugging messages for power supply class
 	  and drivers.
 
+config PDA_POWER
+	tristate "Generic PDA/phone power driver"
+	help
+	  Say Y here to enable generic power driver for PDAs and phones with
+	  one or two external power supplies (AC/USB) connected to main and
+	  backup batteries, and optional builtin charger.
+
 endif # POWER_SUPPLY

drivers/power/Makefile

@@ -13,3 +13,5 @@ EXTRA_CFLAGS += -DDEBUG
 endif
 
 obj-$(CONFIG_POWER_SUPPLY)	+= power_supply.o
+
+obj-$(CONFIG_PDA_POWER)		+= pda_power.o

drivers/power/pda_power.c

+/*
+ * Common power driver for PDAs and phones with one or two external
+ * power supplies (AC/USB) connected to main and backup batteries,
+ * and optional builtin charger.
+ *
+ * Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/power_supply.h>
+#include <linux/pda_power.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+
+static inline unsigned int get_irq_flags(struct resource *res)
+{
+	unsigned int flags = IRQF_DISABLED | IRQF_SHARED;
+
+	flags |= res->flags & IRQF_TRIGGER_MASK;
+
+	return flags;
+}
+
+static struct device *dev;
+static struct pda_power_pdata *pdata;
+static struct resource *ac_irq, *usb_irq;
+static struct timer_list charger_timer;
+static struct timer_list supply_timer;
+
+static int pda_power_get_property(struct power_supply *psy,
+				  enum power_supply_property psp,
+				  union power_supply_propval *val)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		if (psy->type == POWER_SUPPLY_TYPE_MAINS)
+			val->intval = pdata->is_ac_online ?
+				      pdata->is_ac_online() : 0;
+		else
+			val->intval = pdata->is_usb_online ?
+				      pdata->is_usb_online() : 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static enum power_supply_property pda_power_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+static char *pda_power_supplied_to[] = {
+	"main-battery",
+	"backup-battery",
+};
+
+static struct power_supply pda_power_supplies[] = {
+	{
+		.name = "ac",
+		.type = POWER_SUPPLY_TYPE_MAINS,
+		.supplied_to = pda_power_supplied_to,
+		.num_supplicants = ARRAY_SIZE(pda_power_supplied_to),
+		.properties = pda_power_props,
+		.num_properties = ARRAY_SIZE(pda_power_props),
+		.get_property = pda_power_get_property,
+	},
+	{
+		.name = "usb",
+		.type = POWER_SUPPLY_TYPE_USB,
+		.supplied_to = pda_power_supplied_to,
+		.num_supplicants = ARRAY_SIZE(pda_power_supplied_to),
+		.properties = pda_power_props,
+		.num_properties = ARRAY_SIZE(pda_power_props),
+		.get_property = pda_power_get_property,
+	},
+};
+
+static void update_charger(void)
+{
+	if (!pdata->set_charge)
+		return;
+
+	if (pdata->is_ac_online && pdata->is_ac_online()) {
+		dev_dbg(dev, "charger on (AC)\n");
+		pdata->set_charge(PDA_POWER_CHARGE_AC);
+	} else if (pdata->is_usb_online && pdata->is_usb_online()) {
+		dev_dbg(dev, "charger on (USB)\n");
+		pdata->set_charge(PDA_POWER_CHARGE_USB);
+	} else {
+		dev_dbg(dev, "charger off\n");
+		pdata->set_charge(0);
+	}
+
+	return;
+}
+
+static void supply_timer_func(unsigned long irq)
+{
+	if (ac_irq && irq == ac_irq->start)
+		power_supply_changed(&pda_power_supplies[0]);
+	else if (usb_irq && irq == usb_irq->start)
+		power_supply_changed(&pda_power_supplies[1]);
+	return;
+}
+
+static void charger_timer_func(unsigned long irq)
+{
+	update_charger();
+
+	/* Okay, charger set. Now wait a bit before notifying supplicants,
+	 * charge power should stabilize. */
+	supply_timer.data = irq;
+	mod_timer(&supply_timer,
+		  jiffies + msecs_to_jiffies(pdata->wait_for_charger));
+	return;
+}
+
+static irqreturn_t power_changed_isr(int irq, void *unused)
+{
+	/* Wait a bit before reading ac/usb line status and setting charger,
+	 * because ac/usb status readings may lag from irq. */
+	charger_timer.data = irq;
+	mod_timer(&charger_timer,
+		  jiffies + msecs_to_jiffies(pdata->wait_for_status));
+	return IRQ_HANDLED;
+}
+
+static int pda_power_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+
+	dev = &pdev->dev;
+
+	if (pdev->id != -1) {
+		dev_err(dev, "it's meaningless to register several "
+			"pda_powers; use id = -1\n");
+		ret = -EINVAL;
+		goto wrongid;
+	}
+
+	pdata = pdev->dev.platform_data;
+
+	update_charger();
+
+	if (!pdata->wait_for_status)
+		pdata->wait_for_status = 500;
+
+	if (!pdata->wait_for_charger)
+		pdata->wait_for_charger = 500;
+
+	setup_timer(&charger_timer, charger_timer_func, 0);
+	setup_timer(&supply_timer, supply_timer_func, 0);
+
+	ac_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "ac");
+	usb_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "usb");
+	if (!ac_irq && !usb_irq) {
+		dev_err(dev, "no ac/usb irq specified\n");
+		ret = -ENODEV;
+		goto noirqs;
+	}
+
+	if (pdata->supplied_to) {
+		pda_power_supplies[0].supplied_to = pdata->supplied_to;
+		pda_power_supplies[1].supplied_to = pdata->supplied_to;
+		pda_power_supplies[0].num_supplicants = pdata->num_supplicants;
+		pda_power_supplies[1].num_supplicants = pdata->num_supplicants;
+	}
+
+	ret = power_supply_register(&pdev->dev, &pda_power_supplies[0]);
+	if (ret) {
+		dev_err(dev, "failed to register %s power supply\n",
+			pda_power_supplies[0].name);
+		goto supply0_failed;
+	}
+
+	ret = power_supply_register(&pdev->dev, &pda_power_supplies[1]);
+	if (ret) {
+		dev_err(dev, "failed to register %s power supply\n",
+			pda_power_supplies[1].name);
+		goto supply1_failed;
+	}
+
+	if (ac_irq) {
+		ret = request_irq(ac_irq->start, power_changed_isr,
+				  get_irq_flags(ac_irq), ac_irq->name,
+				  &pda_power_supplies[0]);
+		if (ret) {
+			dev_err(dev, "request ac irq failed\n");
+			goto ac_irq_failed;
+		}
+	}
+
+	if (usb_irq) {
+		ret = request_irq(usb_irq->start, power_changed_isr,
+				  get_irq_flags(usb_irq), usb_irq->name,
+				  &pda_power_supplies[1]);
+		if (ret) {
+			dev_err(dev, "request usb irq failed\n");
+			goto usb_irq_failed;
+		}
+	}
+
+	goto success;
+
+usb_irq_failed:
+	if (ac_irq)
+		free_irq(ac_irq->start, &pda_power_supplies[0]);
+ac_irq_failed:
+	power_supply_unregister(&pda_power_supplies[1]);
+supply1_failed:
+	power_supply_unregister(&pda_power_supplies[0]);
+supply0_failed:
+noirqs:
+wrongid:
+success:
+	return ret;
+}
+
+static int pda_power_remove(struct platform_device *pdev)
+{
+	if (usb_irq)
+		free_irq(usb_irq->start, &pda_power_supplies[1]);
+	if (ac_irq)
+		free_irq(ac_irq->start, &pda_power_supplies[0]);
+	del_timer_sync(&charger_timer);
+	del_timer_sync(&supply_timer);
+	power_supply_unregister(&pda_power_supplies[1]);
+	power_supply_unregister(&pda_power_supplies[0]);
+	return 0;
+}
+
+static struct platform_driver pda_power_pdrv = {
+	.driver = {
+		.name = "pda-power",
+	},
+	.probe = pda_power_probe,
+	.remove = pda_power_remove,
+};
+
+static int __init pda_power_init(void)
+{
+	return platform_driver_register(&pda_power_pdrv);
+}
+
+static void __exit pda_power_exit(void)
+{
+	platform_driver_unregister(&pda_power_pdrv);
+	return;
+}
+
+module_init(pda_power_init);
+module_exit(pda_power_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Anton Vorontsov <cbou@mail.ru>");

include/linux/pda_power.h

+/*
+ * Common power driver for PDAs and phones with one or two external
+ * power supplies (AC/USB) connected to main and backup batteries,
+ * and optional builtin charger.
+ *
+ * Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
+ *
+ * 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.
+ */
+
+#ifndef __PDA_POWER_H__
+#define __PDA_POWER_H__
+
+#define PDA_POWER_CHARGE_AC  (1 << 0)
+#define PDA_POWER_CHARGE_USB (1 << 1)
+
+struct pda_power_pdata {
+	int (*is_ac_online)(void);
+	int (*is_usb_online)(void);
+	void (*set_charge)(int flags);
+
+	char **supplied_to;
+	size_t num_supplicants;
+
+	unsigned int wait_for_status; /* msecs, default is 500 */
+	unsigned int wait_for_charger; /* msecs, default is 500 */
+};
+
+#endif /* __PDA_POWER_H__ */