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Commit 9705ecc5 authored by Balaji Rao's avatar Balaji Rao Committed by Anton Vorontsov
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pcf50633_charger: Enable periodic charging restart 



The battery charger 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 at regular intervals to
make sure the battery doesn't discharge too much.

Signed-off-by: default avatarBalaji Rao <balajirrao@openmoko.org>
Cc: Andy Green <andy@openmoko.com>
Signed-off-by: default avatarAnton Vorontsov <cbouatmailru@gmail.com>
parent ccc9c8b9

drivers/power/pcf50633-charger.c

+71 −2
Original line number Diff line number Diff line
@@ -36,6 +36,8 @@ struct pcf50633_mbc { 


	struct power_supply usb;

	struct power_supply adapter;



	struct delayed_work charging_restart_work;

};



int pcf50633_mbc_usb_curlim_set(struct pcf50633 *pcf, int ma)
@@ -43,6 +45,8 @@ int pcf50633_mbc_usb_curlim_set(struct pcf50633 *pcf, int ma) 
	struct pcf50633_mbc *mbc = platform_get_drvdata(pcf->mbc_pdev);

	int ret = 0;

	u8 bits;

	int charging_start = 1;

	u8 mbcs2, chgmod;



	if (ma >= 1000)

		bits = PCF50633_MBCC7_USB_1000mA;
@@ -50,8 +54,10 @@ int pcf50633_mbc_usb_curlim_set(struct pcf50633 *pcf, int ma) 
		bits = PCF50633_MBCC7_USB_500mA;

	else if (ma >= 100)

		bits = PCF50633_MBCC7_USB_100mA;

	else

	else {

		bits = PCF50633_MBCC7_USB_SUSPEND;

		charging_start = 0;

	}



	ret = pcf50633_reg_set_bit_mask(pcf, PCF50633_REG_MBCC7,

					PCF50633_MBCC7_USB_MASK, bits);
@@ -60,6 +66,22 @@ int pcf50633_mbc_usb_curlim_set(struct pcf50633 *pcf, int ma) 
	else

		dev_info(pcf->dev, "usb curlim to %d mA\n", ma);



	/* Manual charging start */

	mbcs2 = pcf50633_reg_read(pcf, PCF50633_REG_MBCS2);

	chgmod = (mbcs2 & PCF50633_MBCS2_MBC_MASK);



	/* If chgmod == BATFULL, setting chgena has no effect.

	 * We need to set resume instead.

	 */

	if (chgmod != PCF50633_MBCS2_MBC_BAT_FULL)

		pcf50633_reg_set_bit_mask(pcf, PCF50633_REG_MBCC1,

				PCF50633_MBCC1_CHGENA, PCF50633_MBCC1_CHGENA);

	else

		pcf50633_reg_set_bit_mask(pcf, PCF50633_REG_MBCC1,

				PCF50633_MBCC1_RESUME, PCF50633_MBCC1_RESUME);



	mbc->usb_active = charging_start;



	power_supply_changed(&mbc->usb);



	return ret;
@@ -160,10 +182,44 @@ 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 at regular intervals to make

 * 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) {
@@ -172,6 +228,7 @@ 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 */
@@ -186,7 +243,14 @@ 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)

		mbc->usb_active = 1;



	power_supply_changed(&mbc->usb);

	power_supply_changed(&mbc->adapter);
@@ -303,6 +367,9 @@ static int __devinit pcf50633_mbc_probe(struct platform_device *pdev) 
		return ret;

	}



	INIT_DELAYED_WORK(&mbc->charging_restart_work,

				pcf50633_mbc_charging_restart);



	ret = sysfs_create_group(&pdev->dev.kobj, &mbc_attr_group);

	if (ret)

		dev_err(mbc->pcf->dev, "failed to create sysfs entries\n");
@@ -328,6 +395,8 @@ 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;

include/linux/mfd/pcf50633/core.h

+2 −0
Original line number Diff line number Diff line
@@ -29,6 +29,8 @@ struct pcf50633_platform_data { 
	char **batteries;

	int num_batteries;



	int charging_restart_interval;



	/* Callbacks */

	void (*probe_done)(struct pcf50633 *);

	void (*mbc_event_callback)(struct pcf50633 *, int);