5 files changed, 160 insertions, 0 deletions

diff --git a/drivers/power/ab8500_charger.c b/drivers/power/ab8500_charger.c
index 6fea4fdf8701..f249a65b02e1 100644
--- a/drivers/power/ab8500_charger.c
+++ b/drivers/power/ab8500_charger.c
@@ -1925,6 +1925,67 @@ static int ab8500_charger_update_charger_current(struct ux500_charger *charger,
         return ret;
 }
 
+/**
+ * ab8540_charger_power_path_enable() - enable usb power path mode
+ * @charger:    pointer to the ux500_charger structure
+ * @enable:     enable/disable flag
+ *
+ * Enable or disable the power path for usb mode
+ * Returns error code in case of failure else 0(on success)
+ */
+static int ab8540_charger_power_path_enable(struct ux500_charger *charger,
+                bool enable)
+{
+        int ret;
+        struct ab8500_charger *di;
+
+        if (charger->psy.type == POWER_SUPPLY_TYPE_USB)
+                di = to_ab8500_charger_usb_device_info(charger);
+        else
+                return -ENXIO;
+
+        ret = abx500_mask_and_set_register_interruptible(di->dev,
+                                AB8500_CHARGER, AB8540_USB_PP_MODE_REG,
+                                BUS_POWER_PATH_MODE_ENA, enable);
+        if (ret) {
+                dev_err(di->dev, "%s write failed\n", __func__);
+                return ret;
+        }
+
+        return ret;
+}
+
+
+/**
+ * ab8540_charger_usb_pre_chg_enable() - enable usb pre change
+ * @charger:    pointer to the ux500_charger structure
+ * @enable:     enable/disable flag
+ *
+ * Enable or disable the pre-chage for usb mode
+ * Returns error code in case of failure else 0(on success)
+ */
+static int ab8540_charger_usb_pre_chg_enable(struct ux500_charger *charger,
+                bool enable)
+{
+        int ret;
+        struct ab8500_charger *di;
+
+        if (charger->psy.type == POWER_SUPPLY_TYPE_USB)
+                di = to_ab8500_charger_usb_device_info(charger);
+        else
+                return -ENXIO;
+
+        ret = abx500_mask_and_set_register_interruptible(di->dev,
+                                AB8500_CHARGER, AB8540_USB_PP_CHR_REG,
+                                BUS_POWER_PATH_PRECHG_ENA, enable);
+        if (ret) {
+                dev_err(di->dev, "%s write failed\n", __func__);
+                return ret;
+        }
+
+        return ret;
+}
+
 static int ab8500_charger_get_ext_psy_data(struct device *dev, void *data)
 {
         struct power_supply *psy;
@@ -3201,6 +3262,23 @@ static int ab8500_charger_init_hw_registers(struct ab8500_charger *di)
         if (ret < 0)
                 dev_err(di->dev, "%s mask and set failed\n", __func__);
 
+        if (is_ab8540(di->parent)) {
+                ret = abx500_mask_and_set_register_interruptible(di->dev,
+                        AB8500_CHARGER, AB8540_USB_PP_MODE_REG,
+                        BUS_VSYS_VOL_SELECT_MASK, BUS_VSYS_VOL_SELECT_3P6V);
+                if (ret) {
+                        dev_err(di->dev, "failed to setup usb power path vsys voltage\n");
+                        goto out;
+                }
+                ret = abx500_mask_and_set_register_interruptible(di->dev,
+                        AB8500_CHARGER, AB8540_USB_PP_CHR_REG,
+                        BUS_PP_PRECHG_CURRENT_MASK, 0);
+                if (ret) {
+                        dev_err(di->dev, "failed to setup usb power path prechage current\n");
+                        goto out;
+                }
+        }
+
 out:
         return ret;
 }
@@ -3484,6 +3562,8 @@ static int ab8500_charger_probe(struct platform_device *pdev)
         di->usb_chg.ops.check_enable = &ab8500_charger_usb_check_enable;
         di->usb_chg.ops.kick_wd = &ab8500_charger_watchdog_kick;
         di->usb_chg.ops.update_curr = &ab8500_charger_update_charger_current;
+        di->usb_chg.ops.pp_enable = &ab8540_charger_power_path_enable;
+        di->usb_chg.ops.pre_chg_enable = &ab8540_charger_usb_pre_chg_enable;
         di->usb_chg.max_out_volt = ab8500_charger_voltage_map[
                 ARRAY_SIZE(ab8500_charger_voltage_map) - 1];
         di->usb_chg.max_out_curr = ab8500_charger_current_map[
@@ -3491,6 +3571,7 @@ static int ab8500_charger_probe(struct platform_device *pdev)
         di->usb_chg.wdt_refresh = CHG_WD_INTERVAL;
         di->usb_chg.enabled = di->bm->usb_enabled;
         di->usb_chg.external = false;
+        di->usb_chg.power_path = di->bm->usb_power_path;
         di->usb_state.usb_current = -1;
 
         /* Create a work queue for the charger */
diff --git a/drivers/power/abx500_chargalg.c b/drivers/power/abx500_chargalg.c
index a876976678ab..a9b8efdafb8f 100644
--- a/drivers/power/abx500_chargalg.c
+++ b/drivers/power/abx500_chargalg.c
@@ -34,6 +34,9 @@
 /* End-of-charge criteria counter */
 #define EOC_COND_CNT                    10
 
+/* Plus margin for the low battery threshold */
+#define BAT_PLUS_MARGIN                (100)
+
 #define to_abx500_chargalg_device_info(x) container_of((x), \
         struct abx500_chargalg, chargalg_psy);
 
@@ -83,6 +86,7 @@ enum abx500_chargalg_states {
         STATE_HW_TEMP_PROTECT_INIT,
         STATE_HW_TEMP_PROTECT,
         STATE_NORMAL_INIT,
+        STATE_USB_PP_PRE_CHARGE,
         STATE_NORMAL,
         STATE_WAIT_FOR_RECHARGE_INIT,
         STATE_WAIT_FOR_RECHARGE,
@@ -114,6 +118,7 @@ static const char *states[] = {
         "HW_TEMP_PROTECT_INIT",
         "HW_TEMP_PROTECT",
         "NORMAL_INIT",
+        "USB_PP_PRE_CHARGE",
         "NORMAL",
         "WAIT_FOR_RECHARGE_INIT",
         "WAIT_FOR_RECHARGE",
@@ -560,6 +565,37 @@ static int abx500_chargalg_usb_en(struct abx500_chargalg *di, int enable,
         return di->usb_chg->ops.enable(di->usb_chg, enable, vset, iset);
 }
 
+ /**
+ * ab8540_chargalg_usb_pp_en() - Enable/ disable USB power path
+ * @di:                pointer to the abx500_chargalg structure
+ * @enable:    power path enable/disable
+ *
+ * The USB power path will be enable/ disable
+ */
+static int ab8540_chargalg_usb_pp_en(struct abx500_chargalg *di, bool enable)
+{
+        if (!di->usb_chg || !di->usb_chg->ops.pp_enable)
+                return -ENXIO;
+
+        return di->usb_chg->ops.pp_enable(di->usb_chg, enable);
+}
+
+/**
+ * ab8540_chargalg_usb_pre_chg_en() - Enable/ disable USB pre-charge
+ * @di:                pointer to the abx500_chargalg structure
+ * @enable:    USB pre-charge enable/disable
+ *
+ * The USB USB pre-charge will be enable/ disable
+ */
+static int ab8540_chargalg_usb_pre_chg_en(struct abx500_chargalg *di,
+                                          bool enable)
+{
+        if (!di->usb_chg || !di->usb_chg->ops.pre_chg_enable)
+                return -ENXIO;
+
+        return di->usb_chg->ops.pre_chg_enable(di->usb_chg, enable);
+}
+
 /**
  * abx500_chargalg_update_chg_curr() - Update charger current
  * @di:         pointer to the abx500_chargalg structure
@@ -765,6 +801,9 @@ static void abx500_chargalg_end_of_charge(struct abx500_chargalg *di)
                 di->batt_data.avg_curr > 0) {
                 if (++di->eoc_cnt >= EOC_COND_CNT) {
                         di->eoc_cnt = 0;
+                        if ((di->chg_info.charger_type & USB_CHG) &&
+                           (di->usb_chg->power_path))
+                                ab8540_chargalg_usb_pp_en(di, true);
                         di->charge_status = POWER_SUPPLY_STATUS_FULL;
                         di->maintenance_chg = true;
                         dev_dbg(di->dev, "EOC reached!\n");
@@ -1465,6 +1504,22 @@ static void abx500_chargalg_algorithm(struct abx500_chargalg *di)
                 break;
 
         case STATE_NORMAL_INIT:
+                if ((di->chg_info.charger_type & USB_CHG) &&
+                                di->usb_chg->power_path) {
+                        if (di->batt_data.volt >
+                            (di->bm->fg_params->lowbat_threshold +
+                             BAT_PLUS_MARGIN)) {
+                                ab8540_chargalg_usb_pre_chg_en(di, false);
+                                ab8540_chargalg_usb_pp_en(di, false);
+                        } else {
+                                ab8540_chargalg_usb_pp_en(di, true);
+                                ab8540_chargalg_usb_pre_chg_en(di, true);
+                                abx500_chargalg_state_to(di,
+                                        STATE_USB_PP_PRE_CHARGE);
+                                break;
+                        }
+                }
+
                 abx500_chargalg_start_charging(di,
                         di->bm->bat_type[di->bm->batt_id].normal_vol_lvl,
                         di->bm->bat_type[di->bm->batt_id].normal_cur_lvl);
@@ -1479,6 +1534,13 @@ static void abx500_chargalg_algorithm(struct abx500_chargalg *di)
 
                 break;
 
+        case STATE_USB_PP_PRE_CHARGE:
+                if (di->batt_data.volt >
+                        (di->bm->fg_params->lowbat_threshold +
+                        BAT_PLUS_MARGIN))
+                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
+                break;
+
         case STATE_NORMAL:
                 handle_maxim_chg_curr(di);
                 if (di->charge_status == POWER_SUPPLY_STATUS_FULL &&
diff --git a/include/linux/mfd/abx500.h b/include/linux/mfd/abx500.h
index 188aedc322c2..cd71d8eadf50 100644
--- a/include/linux/mfd/abx500.h
+++ b/include/linux/mfd/abx500.h
@@ -267,6 +267,7 @@ struct abx500_bm_data {
         bool autopower_cfg;
         bool ac_enabled;
         bool usb_enabled;
+        bool usb_power_path;
         bool no_maintenance;
         bool capacity_scaling;
         bool chg_unknown_bat;
diff --git a/include/linux/mfd/abx500/ab8500-bm.h b/include/linux/mfd/abx500/ab8500-bm.h
index a73e05a0441b..0ebf0c5d1f88 100644
--- a/include/linux/mfd/abx500/ab8500-bm.h
+++ b/include/linux/mfd/abx500/ab8500-bm.h
@@ -69,6 +69,8 @@
 #define AB8500_USBCH_CTRL1_REG          0xC0
 #define AB8500_USBCH_CTRL2_REG          0xC1
 #define AB8500_USBCH_IPT_CRNTLVL_REG    0xC2
+#define AB8540_USB_PP_MODE_REG          0xC5
+#define AB8540_USB_PP_CHR_REG           0xC6
 
 /*
  * Gas Gauge register offsets
@@ -259,6 +261,16 @@ enum bup_vch_sel {
 #define AB8505_RTC_PCUT_RESTART_REG     0x16
 #define AB8505_RTC_PCUT_DEBOUNCE_REG    0x17
 
+/* USB Power Path constants for ab8540 */
+#define BUS_VSYS_VOL_SELECT_MASK                0x06
+#define BUS_VSYS_VOL_SELECT_3P6V                0x00
+#define BUS_VSYS_VOL_SELECT_3P325V              0x02
+#define BUS_VSYS_VOL_SELECT_3P9V                0x04
+#define BUS_VSYS_VOL_SELECT_4P3V                0x06
+#define BUS_POWER_PATH_MODE_ENA                 0x01
+#define BUS_PP_PRECHG_CURRENT_MASK              0x0E
+#define BUS_POWER_PATH_PRECHG_ENA               0x01
+
 /**
  * struct res_to_temp - defines one point in a temp to res curve. To
  * be used in battery packs that combines the identification resistor with a
diff --git a/include/linux/mfd/abx500/ux500_chargalg.h b/include/linux/mfd/abx500/ux500_chargalg.h
index fa831f1e8cf8..234c99143bf7 100644
--- a/include/linux/mfd/abx500/ux500_chargalg.h
+++ b/include/linux/mfd/abx500/ux500_chargalg.h
@@ -20,6 +20,8 @@ struct ux500_charger_ops {
         int (*check_enable) (struct ux500_charger *, int, int);
         int (*kick_wd) (struct ux500_charger *);
         int (*update_curr) (struct ux500_charger *, int);
+        int (*pp_enable) (struct ux500_charger *, bool);
+        int (*pre_chg_enable) (struct ux500_charger *, bool);
 };
 
 /**
@@ -30,6 +32,7 @@ struct ux500_charger_ops {
  * @max_out_curr        maximum output charger current in mA
  * @enabled             indicates if this charger is used or not
  * @external            external charger unit (pm2xxx)
+ * @power_path          USB power path support
  */
 struct ux500_charger {
         struct power_supply psy;
@@ -39,6 +42,7 @@ struct ux500_charger {
         int wdt_refresh;
         bool enabled;
         bool external;
+        bool power_path;
 };
 
 extern struct blocking_notifier_head charger_notifier_list;