ab8500-bm: Add usb power path support

AB8540 supports power path function in USB charging mode for fast
power up with dead and weak battery, and it could extend
the battery age.

When USB charging starts, if the Vbattrue is below than SW cut off
voltage, power path and pre-charge should be enabled. If Vbattrue
is higher than SW cut off voltage, power path and pre-charge should
be disabled. This is to make sure full current to battery charge.
At the end of charge, power path should be enable again to reduce
charging the battery again.

Signed-off-by: Lee Jones <lee.jones@linaro.org>

3 files changed, 17 insertions, 0 deletions

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;