[PATCH 1/4] pcf50633: get rid of charging restart software auto-triggering

[Paul Fertser]

After reaching Battery Full condition MBC state machine switches back
into charging mode when the battery voltage falls below 96% of a
battery float voltage. The voltage drop in Li-Ion batteries is
marginal (1-2%) till about 80% of its capacity - which means, after a
BATFULL, charging won't be restarted until 75-80%.

That is a desired behaviour recommended by battery manufacturers,
don't mess with it.

Signed-off-by: Paul Fertser <fercerpav at gmail.com>
---
Unfortunately, we've already diverged from mainline enough (mainline lacks some
features we want to use, e.g. "ac" power_supply device) for this patch to be
not cleanly applicable. I hope to take care of that later.

 drivers/power/pcf50633-charger.c  |   46 -------------------------------------
 include/linux/mfd/pcf50633/core.h |    2 -
 2 files changed, 0 insertions(+), 48 deletions(-)

diff --git a/drivers/power/pcf50633-charger.c b/drivers/power/pcf50633-charger.c
index 1bdb990..cda0c67 100644
--- a/drivers/power/pcf50633-charger.c
+++ b/drivers/power/pcf50633-charger.c
@@ -37,8 +37,6 @@ struct pcf50633_mbc {
 	struct power_supply usb;
 	struct power_supply adapter;
 	struct power_supply ac;
-
-	struct delayed_work charging_restart_work;
 };
 
 int pcf50633_mbc_usb_curlim_set(struct pcf50633 *pcf, int ma)
@@ -226,44 +224,10 @@ static struct attribute_group mbc_attr_group = {
 	.attrs	= pcf50633_mbc_sysfs_entries,
 };
 
-/* MBC state machine switches into charging mode when the battery voltage
- * falls below 96% of a battery float voltage. But the voltage drop in Li-ion
- * batteries is marginal(1~2 %) till about 80% of its capacity - which means,
- * after a BATFULL, charging won't be restarted until 80%.
- *
- * This work_struct function restarts charging every few seconds and makes
- * sure we don't discharge too much
- */
-
-static void pcf50633_mbc_charging_restart(struct work_struct *work)
-{
-	struct pcf50633_mbc *mbc;
-	u8 mbcs2, chgmod;
-
-	mbc = container_of(work, struct pcf50633_mbc,
-				charging_restart_work.work);
-
-	mbcs2 = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCS2);
-	chgmod = (mbcs2 & PCF50633_MBCS2_MBC_MASK);
-
-	if (chgmod != PCF50633_MBCS2_MBC_BAT_FULL)
-		return;
-
-	/* Restart charging */
-	pcf50633_reg_set_bit_mask(mbc->pcf, PCF50633_REG_MBCC1,
-				PCF50633_MBCC1_RESUME, PCF50633_MBCC1_RESUME);
-	mbc->usb_active = 1;
-	power_supply_changed(&mbc->usb);
-
-	dev_info(mbc->pcf->dev, "Charging restarted\n");
-}
-
 static void
 pcf50633_mbc_irq_handler(int irq, void *data)
 {
 	struct pcf50633_mbc *mbc = data;
-	int chg_restart_interval = 
-			mbc->pcf->pdata->charging_restart_interval;
 
 	/* USB */
 	if (irq == PCF50633_IRQ_USBINS) {
@@ -272,7 +236,6 @@ pcf50633_mbc_irq_handler(int irq, void *data)
 		mbc->usb_online = 0;
 		mbc->usb_active = 0;
 		pcf50633_mbc_usb_curlim_set(mbc->pcf, 0);		
-		cancel_delayed_work_sync(&mbc->charging_restart_work);
 	}
 
 	/* Adapter */
@@ -287,10 +250,6 @@ pcf50633_mbc_irq_handler(int irq, void *data)
 	if (irq == PCF50633_IRQ_BATFULL) {
 		mbc->usb_active = 0;
 		mbc->adapter_active = 0;
-
-		if (chg_restart_interval > 0)
-			schedule_delayed_work(&mbc->charging_restart_work,
-							chg_restart_interval);
 	} else if (irq == PCF50633_IRQ_USBLIMON)
 		mbc->usb_active = 0;
 	else if (irq == PCF50633_IRQ_USBLIMOFF)
@@ -428,9 +387,6 @@ static int __devinit pcf50633_mbc_probe(struct platform_device *pdev)
 	mbc->ac.supplied_to		= mbc->pcf->pdata->batteries;
 	mbc->ac.num_supplicants		= mbc->pcf->pdata->num_batteries;
 
-	INIT_DELAYED_WORK(&mbc->charging_restart_work,
-				pcf50633_mbc_charging_restart);
-
 	ret = power_supply_register(&pdev->dev, &mbc->adapter);
 	if (ret) {
 		dev_err(mbc->pcf->dev, "failed to register adapter\n");
@@ -480,8 +436,6 @@ static int __devexit pcf50633_mbc_remove(struct platform_device *pdev)
 	power_supply_unregister(&mbc->usb);
 	power_supply_unregister(&mbc->adapter);
 
-	cancel_delayed_work_sync(&mbc->charging_restart_work);
-
 	kfree(mbc);
 
 	return 0;
diff --git a/include/linux/mfd/pcf50633/core.h b/include/linux/mfd/pcf50633/core.h
index aed1fab..c8125f2 100644
--- a/include/linux/mfd/pcf50633/core.h
+++ b/include/linux/mfd/pcf50633/core.h
@@ -29,8 +29,6 @@ struct pcf50633_platform_data {
 	char **batteries;
 	int num_batteries;
 
-	int charging_restart_interval;
-
 	int chg_ref_current_ma;
 
 	/* Callbacks */
-- 
1.6.0.6