[PATCH RFT 2/2] regulator: ab8500: Optimizeab8540_aux3_regulator_get_voltage_sel

From: Axel Lin
Date: Wed Apr 10 2013 - 02:46:29 EST


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@xxxxxxxxxx>
---
drivers/regulator/ab8500.c | 42 ++++++++++++++++++------------------------
1 file changed, 18 insertions(+), 24 deletions(-)

diff --git a/drivers/regulator/ab8500.c b/drivers/regulator/ab8500.c
index 222a63e..7a86fe6 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,
--
1.7.10.4



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