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>

diff --git a/drivers/regulator/ab8500.c b/drivers/regulator/ab8500.c
index 0a62ef942cfb1ae6b480f6aaa4896461d319a665..29a727ca399bc16150481e869cb509a7827c4a72 100644 (file)
--- 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,