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 <balajirrao@openmoko.org>
Cc: Andy Green <andy@openmoko.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
diff --git a/drivers/power/pcf50633-charger.c b/drivers/power/pcf50633-charger.c
index 41aec2a..1fe1e85 100644
--- a/drivers/power/pcf50633-charger.c
+++ b/drivers/power/pcf50633-charger.c
@@ -36,6 +36,8 @@
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 @@
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 @@
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 @@
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 @@
.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 @@
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 @@
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 @@
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 @@
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 4455b21..c8f51c3 100644
--- a/include/linux/mfd/pcf50633/core.h
+++ b/include/linux/mfd/pcf50633/core.h
@@ -29,6 +29,8 @@
char **batteries;
int num_batteries;
+ int charging_restart_interval;
+
/* Callbacks */
void (*probe_done)(struct pcf50633 *);
void (*mbc_event_callback)(struct pcf50633 *, int);