ab8500-charger: Add backup battery charge voltages on the ab8540

Add 2.7v, 2.9v, 3.0v, 3.2v and 3.3v charging voltages for backup
battery. Before that only 2.5v, 2.6v, 2.8v, 3.1v were available.

Signed-off-by: Yang QU <yang.qu@stericsson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Maxime COQUELIN <maxime.coquelin@stericsson.com>
Reviewed-by: Marcus COOPER <marcus.xm.cooper@stericsson.com>
Tested-by: Xiao Mei ZHANG <xiaomei.zhang@stericsson.com>

2 files changed, 37 insertions, 6 deletions

diff --git a/drivers/power/ab8500_charger.c b/drivers/power/ab8500_charger.c
index 24b30b7ea5ca..fd3fa2beca2b 100644
--- a/drivers/power/ab8500_charger.c
+++ b/drivers/power/ab8500_charger.c
@@ -2836,6 +2836,7 @@ static int ab8500_charger_usb_get_property(struct power_supply *psy,
 static int ab8500_charger_init_hw_registers(struct ab8500_charger *di)
 {
         int ret = 0;
+        u8 bup_vch_range = 0, vbup33_vrtcn = 0;
 
         /* Setup maximum charger current and voltage for ABB cut2.0 */
         if (!is_ab8500_1p1_or_earlier(di->parent)) {
@@ -2945,15 +2946,29 @@ static int ab8500_charger_init_hw_registers(struct ab8500_charger *di)
         }
 
         /* Backup battery voltage and current */
+        if (di->bm->bkup_bat_v > BUP_VCH_SEL_3P1V)
+                bup_vch_range = BUP_VCH_RANGE;
+        if (di->bm->bkup_bat_v == BUP_VCH_SEL_3P3V)
+                vbup33_vrtcn = VBUP33_VRTCN;
+
         ret = abx500_set_register_interruptible(di->dev,
                 AB8500_RTC,
                 AB8500_RTC_BACKUP_CHG_REG,
-                di->bm->bkup_bat_v |
-                di->bm->bkup_bat_i);
+                (di->bm->bkup_bat_v & 0x3) | di->bm->bkup_bat_i);
         if (ret) {
                 dev_err(di->dev, "failed to setup backup battery charging\n");
                 goto out;
         }
+        if (is_ab8540(di->parent)) {
+                ret = abx500_set_register_interruptible(di->dev,
+                        AB8500_RTC,
+                        AB8500_RTC_CTRL1_REG,
+                        bup_vch_range | vbup33_vrtcn);
+                if (ret) {
+                        dev_err(di->dev, "failed to setup backup battery charging\n");
+                        goto out;
+                }
+        }
 
         /* Enable backup battery charging */
         abx500_mask_and_set_register_interruptible(di->dev,
diff --git a/include/linux/mfd/abx500/ab8500-bm.h b/include/linux/mfd/abx500/ab8500-bm.h
index 0efbe0efee7f..a73e05a0441b 100644
--- a/include/linux/mfd/abx500/ab8500-bm.h
+++ b/include/linux/mfd/abx500/ab8500-bm.h
@@ -105,6 +105,7 @@
 #define AB8500_RTC_BACKUP_CHG_REG       0x0C
 #define AB8500_RTC_CC_CONF_REG          0x01
 #define AB8500_RTC_CTRL_REG             0x0B
+#define AB8500_RTC_CTRL1_REG            0x11
 
 /*
  * OTP register offsets
@@ -179,10 +180,25 @@
 #define BUP_ICH_SEL_300UA               0x08
 #define BUP_ICH_SEL_700UA               0x0C
 
-#define BUP_VCH_SEL_2P5V                0x00
-#define BUP_VCH_SEL_2P6V                0x01
-#define BUP_VCH_SEL_2P8V                0x02
-#define BUP_VCH_SEL_3P1V                0x03
+enum bup_vch_sel {
+        BUP_VCH_SEL_2P5V,
+        BUP_VCH_SEL_2P6V,
+        BUP_VCH_SEL_2P8V,
+        BUP_VCH_SEL_3P1V,
+        /*
+         * Note that the following 5 values 2.7v, 2.9v, 3.0v, 3.2v, 3.3v
+         * are only available on ab8540. You can't choose these 5
+         * voltage on ab8500/ab8505/ab9540.
+         */
+        BUP_VCH_SEL_2P7V,
+        BUP_VCH_SEL_2P9V,
+        BUP_VCH_SEL_3P0V,
+        BUP_VCH_SEL_3P2V,
+        BUP_VCH_SEL_3P3V,
+};
+
+#define BUP_VCH_RANGE           0x02
+#define VBUP33_VRTCN            0x01
 
 /* Battery OVV constants */
 #define BATT_OVV_ENA                    0x02