smb347-charger: Fix battery status reporting logic for charger faults

This patch checks for charger status register for determining the
battery charging status and reports Discharing/Charging/Not Charging/Full
accordingly.

This patch also adds the interrupt support for Safety Timer Expiration.
This interrupt is helpful in debugging the cause for charger fault.

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

diff --git a/drivers/power/smb347-charger.c b/drivers/power/smb347-charger.c
index 332dd0110bda36e6c7c09a60c98d5bed23d5d3cd..a9707c11fbed47a9cc8444b6f0b4812d50fcd8d9 100644 (file)
--- a/drivers/power/smb347-charger.c
+++ b/drivers/power/smb347-charger.c
@@ -80,6 +80,7 @@
 #define CFG_FAULT_IRQ_DCIN_UV                  BIT(2)
 #define CFG_STATUS_IRQ                         0x0d
 #define CFG_STATUS_IRQ_TERMINATION_OR_TAPER    BIT(4)
+#define CFG_STATUS_IRQ_CHARGE_TIMEOUT          BIT(7)
 #define CFG_ADDRESS                            0x0e
 
 /* Command registers */
@@ -96,6 +97,9 @@
 #define IRQSTAT_C_TERMINATION_STAT             BIT(0)
 #define IRQSTAT_C_TERMINATION_IRQ              BIT(1)
 #define IRQSTAT_C_TAPER_IRQ                    BIT(3)
+#define IRQSTAT_D                              0x38
+#define IRQSTAT_D_CHARGE_TIMEOUT_STAT          BIT(2)
+#define IRQSTAT_D_CHARGE_TIMEOUT_IRQ           BIT(3)
 #define IRQSTAT_E                              0x39
 #define IRQSTAT_E_USBIN_UV_STAT                        BIT(0)
 #define IRQSTAT_E_USBIN_UV_IRQ                 BIT(1)
@@ -109,8 +113,10 @@
 #define STAT_B                                 0x3c
 #define STAT_C                                 0x3d
 #define STAT_C_CHG_ENABLED                     BIT(0)
+#define STAT_C_HOLDOFF_STAT                    BIT(3)
 #define STAT_C_CHG_MASK                                0x06
 #define STAT_C_CHG_SHIFT                       1
+#define STAT_C_CHG_TERM                                BIT(5)
 #define STAT_C_CHARGER_ERROR                   BIT(6)
 #define STAT_E                                 0x3f
 
@@ -701,7 +707,7 @@ fail:
 static irqreturn_t smb347_interrupt(int irq, void *data)
 {
        struct smb347_charger *smb = data;
-       unsigned int stat_c, irqstat_e, irqstat_c;
+       unsigned int stat_c, irqstat_c, irqstat_d, irqstat_e;
        bool handled = false;
        int ret;
 
@@ -717,6 +723,12 @@ static irqreturn_t smb347_interrupt(int irq, void *data)
                return IRQ_NONE;
        }
 
+       ret = regmap_read(smb->regmap, IRQSTAT_D, &irqstat_d);
+       if (ret < 0) {
+               dev_warn(smb->dev, "reading IRQSTAT_D failed\n");
+               return IRQ_NONE;
+       }
+
        ret = regmap_read(smb->regmap, IRQSTAT_E, &irqstat_e);
        if (ret < 0) {
                dev_warn(smb->dev, "reading IRQSTAT_E failed\n");
@@ -724,13 +736,11 @@ static irqreturn_t smb347_interrupt(int irq, void *data)
        }
 
        /*
-        * If we get charger error we report the error back to user and
-        * disable charging.
+        * If we get charger error we report the error back to user.
+        * If the error is recovered charging will resume again.
         */
        if (stat_c & STAT_C_CHARGER_ERROR) {
-               dev_err(smb->dev, "error in charger, disabling charging\n");
-
-               smb347_charging_disable(smb);
+               dev_err(smb->dev, "charging stopped due to charger error\n");
                power_supply_changed(&smb->battery);
                handled = true;
        }
@@ -743,6 +753,20 @@ static irqreturn_t smb347_interrupt(int irq, void *data)
        if (irqstat_c & (IRQSTAT_C_TERMINATION_IRQ | IRQSTAT_C_TAPER_IRQ)) {
                if (irqstat_c & IRQSTAT_C_TERMINATION_STAT)
                        power_supply_changed(&smb->battery);
+               dev_dbg(smb->dev, "going to HW maintenance mode\n");
+               handled = true;
+       }
+
+       /*
+        * If we got a charger timeout INT that means the charge
+        * full is not detected with in charge timeout value.
+        */
+       if (irqstat_d & IRQSTAT_D_CHARGE_TIMEOUT_IRQ) {
+               dev_dbg(smb->dev, "total Charge Timeout INT received\n");
+
+               if (irqstat_d & IRQSTAT_D_CHARGE_TIMEOUT_STAT)
+                       dev_warn(smb->dev, "charging stopped due to timeout\n");
+               power_supply_changed(&smb->battery);
                handled = true;
        }
 
@@ -776,6 +800,7 @@ static int smb347_irq_set(struct smb347_charger *smb, bool enable)
         * Enable/disable interrupts for:
         *      - under voltage
         *      - termination current reached
+        *      - charger timeout
         *      - charger error
         */
        ret = regmap_update_bits(smb->regmap, CFG_FAULT_IRQ, 0xff,
@@ -784,7 +809,8 @@ static int smb347_irq_set(struct smb347_charger *smb, bool enable)
                goto fail;
 
        ret = regmap_update_bits(smb->regmap, CFG_STATUS_IRQ, 0xff,
-                       enable ? CFG_STATUS_IRQ_TERMINATION_OR_TAPER : 0);
+                       enable ? (CFG_STATUS_IRQ_TERMINATION_OR_TAPER |
+                                       CFG_STATUS_IRQ_CHARGE_TIMEOUT) : 0);
        if (ret < 0)
                goto fail;
 
@@ -988,6 +1014,51 @@ static enum power_supply_property smb347_usb_properties[] = {
        POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
 };
 
+static int smb347_get_charging_status(struct smb347_charger *smb)
+{
+       int ret, status;
+       unsigned int val;
+
+       if (!smb347_is_ps_online(smb))
+               return POWER_SUPPLY_STATUS_DISCHARGING;
+
+       ret = regmap_read(smb->regmap, STAT_C, &val);
+       if (ret < 0)
+               return ret;
+
+       if ((val & STAT_C_CHARGER_ERROR) ||
+                       (val & STAT_C_HOLDOFF_STAT)) {
+               /*
+                * set to NOT CHARGING upon charger error
+                * or charging has stopped.
+                */
+               status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+       } else {
+               if ((val & STAT_C_CHG_MASK) >> STAT_C_CHG_SHIFT) {
+                       /*
+                        * set to charging if battery is in pre-charge,
+                        * fast charge or taper charging mode.
+                        */
+                       status = POWER_SUPPLY_STATUS_CHARGING;
+               } else if (val & STAT_C_CHG_TERM) {
+                       /*
+                        * set the status to FULL if battery is not in pre
+                        * charge, fast charge or taper charging mode AND
+                        * charging is terminated at least once.
+                        */
+                       status = POWER_SUPPLY_STATUS_FULL;
+               } else {
+                       /*
+                        * in this case no charger error or termination
+                        * occured but charging is not in progress!!!
+                        */
+                       status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+               }
+       }
+
+       return status;
+}
+
 static int smb347_battery_get_property(struct power_supply *psy,
                                       enum power_supply_property prop,
                                       union power_supply_propval *val)
@@ -1003,14 +1074,10 @@ static int smb347_battery_get_property(struct power_supply *psy,
 
        switch (prop) {
        case POWER_SUPPLY_PROP_STATUS:
-               if (!smb347_is_ps_online(smb)) {
-                       val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
-                       break;
-               }
-               if (smb347_charging_status(smb))
-                       val->intval = POWER_SUPPLY_STATUS_CHARGING;
-               else
-                       val->intval = POWER_SUPPLY_STATUS_FULL;
+               ret = smb347_get_charging_status(smb);
+               if (ret < 0)
+                       return ret;
+               val->intval = ret;
                break;
 
        case POWER_SUPPLY_PROP_CHARGE_TYPE: