regulator: ab8500: Optimize ab8540_aux3_regulator_get_voltage_sel

We can save a register read operation in some case if read
expand_register first.
If info->expand_register.voltage_mask bit is set, no need to read
voltage_reg.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Bengt Jonsson <bengt.g.jonsson@stericsson.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 18 insertions, 24 deletions

diff --git a/drivers/regulator/ab8500.c b/drivers/regulator/ab8500.c
index 0a62ef942cfb..29a727ca399b 100644
--- a/drivers/regulator/ab8500.c
+++ b/drivers/regulator/ab8500.c
@@ -521,7 +521,7 @@ static int ab8500_regulator_get_voltage_sel(struct regulator_dev *rdev)
 
 static int ab8540_aux3_regulator_get_voltage_sel(struct regulator_dev *rdev)
 {
-        int ret, val;
+        int ret;
         struct ab8500_regulator_info *info = rdev_get_drvdata(rdev);
         u8 regval, regval_expand;
 
@@ -531,18 +531,25 @@ static int ab8540_aux3_regulator_get_voltage_sel(struct regulator_dev *rdev)
         }
 
         ret = abx500_get_register_interruptible(info->dev,
-                        info->voltage_bank, info->voltage_reg, &regval);
-
+                        info->expand_register.voltage_bank,
+                        info->expand_register.voltage_reg, &regval_expand);
         if (ret < 0) {
                 dev_err(rdev_get_dev(rdev),
-                        "couldn't read voltage reg for regulator\n");
+                        "couldn't read voltage expand reg for regulator\n");
                 return ret;
         }
 
-        ret = abx500_get_register_interruptible(info->dev,
-                        info->expand_register.voltage_bank,
-                        info->expand_register.voltage_reg, &regval_expand);
+        dev_vdbg(rdev_get_dev(rdev),
+                 "%s-get_voltage expand (bank, reg, mask, value): 0x%x, 0x%x, 0x%x, 0x%x\n",
+                 info->desc.name, info->expand_register.voltage_bank,
+                 info->expand_register.voltage_reg,
+                 info->expand_register.voltage_mask, regval_expand);
 
+        if (regval_expand & info->expand_register.voltage_mask)
+                return info->expand_register.voltage_limit;
+
+        ret = abx500_get_register_interruptible(info->dev,
+                        info->voltage_bank, info->voltage_reg, &regval);
         if (ret < 0) {
                 dev_err(rdev_get_dev(rdev),
                         "couldn't read voltage reg for regulator\n");
@@ -550,24 +557,11 @@ static int ab8540_aux3_regulator_get_voltage_sel(struct regulator_dev *rdev)
         }
 
         dev_vdbg(rdev_get_dev(rdev),
-                "%s-get_voltage (bank, reg, mask, value): 0x%x, 0x%x, 0x%x,"
-                " 0x%x\n",
-                info->desc.name, info->voltage_bank, info->voltage_reg,
-                info->voltage_mask, regval);
-        dev_vdbg(rdev_get_dev(rdev),
-                "%s-get_voltage expand (bank, reg, mask, value): 0x%x, 0x%x, 0x%x,"
-                " 0x%x\n",
-                info->desc.name, info->expand_register.voltage_bank,
-                info->expand_register.voltage_reg,
-                info->expand_register.voltage_mask, regval_expand);
-
-        if (regval_expand&(info->expand_register.voltage_mask))
-                /* Vaux3 has a different layout */
-                val = info->expand_register.voltage_limit;
-        else
-                val = (regval & info->voltage_mask) >> info->voltage_shift;
+                 "%s-get_voltage (bank, reg, mask, value): 0x%x, 0x%x, 0x%x, 0x%x\n",
+                 info->desc.name, info->voltage_bank, info->voltage_reg,
+                 info->voltage_mask, regval);
 
-        return val;
+        return (regval & info->voltage_mask) >> info->voltage_shift;
 }
 
 static int ab8500_regulator_set_voltage_sel(struct regulator_dev *rdev,