From 9705ecc5c1f8f34f756164a711b4cc61110c0283 Mon Sep 17 00:00:00 2001 From: Balaji Rao Date: Tue, 27 Jan 2009 19:23:12 +0530 Subject: 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: Balaji Rao Cc: Andy Green Signed-off-by: Anton Vorontsov --- drivers/power/pcf50633-charger.c | 73 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 71 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/power/pcf50633-charger.c b/drivers/power/pcf50633-charger.c index 41aec2acbb91..1fe1e851a8dd 100644 --- a/drivers/power/pcf50633-charger.c +++ b/drivers/power/pcf50633-charger.c @@ -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; -- cgit v1.2.3