power: pm8921-charger: limit charger current
Not all chargers can support 1500mA. If a high current is drawn from
such a charger, it drops its voltage rapidly. The vin_min regulation
loop does not kick in because of such rapid decline in the voltage.
This drop causes the pmic to see that the charger is removed and it
stops drawing any current from it. This in turn causes the charger to
raise its voltage but the pmic again draws a high current causing it
to collapse. This collapse and build up or removal and reinsertion
continues indefinitely.
Use the max_current module parameter to set the max
current drawn from charger to prevent it from collapsing voltage.
Also an issue was noticed when sometimes the system enters suspend
while the wall charger is plugged in and charging starts while the
device is suspended. Make the fastchg interrupt wake able so that the
driver can start end of charge worker.
Change-Id: I03f7f60d0bc8a87f7da59af947649a8190ab7994
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
diff --git a/drivers/power/pm8921-charger.c b/drivers/power/pm8921-charger.c
index c40f13e..51ec91c 100644
--- a/drivers/power/pm8921-charger.c
+++ b/drivers/power/pm8921-charger.c
@@ -263,6 +263,7 @@
enum pm8921_chg_hot_thr hot_thr;
};
+static int usb_max_current;
static int charging_disabled;
static int thermal_mitigation;
@@ -575,6 +576,22 @@
return 0;
}
+struct usb_ma_limit_entry {
+ int usb_ma;
+ u8 chg_iusb_value;
+};
+
+static struct usb_ma_limit_entry usb_ma_table[] = {
+ {100, 0},
+ {500, 1},
+ {700, 2},
+ {850, 3},
+ {900, 4},
+ {1100, 5},
+ {1300, 6},
+ {1500, 7},
+};
+
#define PM8921_CHG_IUSB_MASK 0x1C
#define PM8921_CHG_IUSB_MAX 7
#define PM8921_CHG_IUSB_MIN 0
@@ -591,6 +608,26 @@
temp);
}
+static int pm_chg_iusbmax_get(struct pm8921_chg_chip *chip, int *mA)
+{
+ u8 temp;
+ int i, rc;
+
+ *mA = 0;
+ rc = pm8xxx_readb(chip->dev->parent, PBL_ACCESS2, &temp);
+ if (rc) {
+ pr_err("err=%d reading PBL_ACCESS2\n", rc);
+ return rc;
+ }
+ temp &= PM8921_CHG_IUSB_MASK;
+ temp = temp >> 2;
+ for (i = ARRAY_SIZE(usb_ma_table) - 1; i >= 0; i--) {
+ if (usb_ma_table[i].chg_iusb_value == temp)
+ *mA = usb_ma_table[i].usb_ma;
+ }
+ return rc;
+}
+
#define PM8921_CHG_WD_MASK 0x1F
static int pm_chg_disable_wd(struct pm8921_chg_chip *chip)
{
@@ -1209,27 +1246,17 @@
}
}
-struct usb_ma_limit_entry {
- int usb_ma;
- u8 chg_iusb_value;
-};
-
-static struct usb_ma_limit_entry usb_ma_table[] = {
- {100, 0},
- {500, 1},
- {700, 2},
- {850, 3},
- {900, 4},
- {1100, 5},
- {1300, 6},
- {1500, 7},
-};
-
/* assumes vbus_lock is held */
static void __pm8921_charger_vbus_draw(unsigned int mA)
{
int i, rc;
+ if (usb_max_current && mA > usb_max_current) {
+ pr_warn("restricting usb current to %d instead of %d\n",
+ usb_max_current, mA);
+ mA = usb_max_current;
+ }
+
if (mA > 0 && mA <= 2) {
usb_chg_current = 0;
rc = pm_chg_iusbmax_set(the_chip,
@@ -2391,6 +2418,28 @@
param_get_uint,
&thermal_mitigation, 0644);
+static int set_usb_max_current(const char *val, struct kernel_param *kp)
+{
+ int ret, mA;
+ struct pm8921_chg_chip *chip = the_chip;
+
+ ret = param_set_int(val, kp);
+ if (ret) {
+ pr_err("error setting value %d\n", ret);
+ return ret;
+ }
+ if (chip) {
+ pr_warn("setting current max to %d\n", usb_max_current);
+ pm_chg_iusbmax_get(chip, &mA);
+ if (mA > usb_max_current)
+ pm8921_charger_vbus_draw(usb_max_current);
+ return 0;
+ }
+ return -EINVAL;
+}
+module_param_call(usb_max_current, set_usb_max_current, param_get_uint,
+ &usb_max_current, 0644);
+
static void free_irqs(struct pm8921_chg_chip *chip)
{
int i;
@@ -3200,6 +3249,7 @@
enable_irq_wake(chip->pmic_chg_irq[USBIN_UV_IRQ]);
enable_irq_wake(chip->pmic_chg_irq[BAT_TEMP_OK_IRQ]);
enable_irq_wake(chip->pmic_chg_irq[VBATDET_LOW_IRQ]);
+ enable_irq_wake(chip->pmic_chg_irq[FASTCHG_IRQ]);
/*
* if both the cool_temp_dc and warm_temp_dc are invalid device doesnt
* care for jeita compliance