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authorAxel Lin <axel.lin@gmail.com>2012-07-09 11:22:31 +0800
committerMark Brown <broonie@opensource.wolfsonmicro.com>2012-07-15 22:06:05 +0100
commita3cb80f43a9bc9b64aedd14b100e99252767d78c (patch)
treee0e12208892082893cb80772c63bbab24a82a83b /drivers/regulator
parent5febb3c9d52c65686a8e473a31f15137852f4b5e (diff)
regulator: twl: Fix the formula to calculate vsel and voltage for twl6030ldo
In twl6030ldo_set_voltage, current code use below formula to calculate vsel: vsel = (min_uV/1000 - 1000)/100 + 1; This is worng because when min_uV is 1000000 uV, vsel is 1. It should be 0 in this case. Fix it by change the equation to: (This equation is common for linear mapping) vsel = DIV_ROUND_UP(min_uV - rdev->desc->min_uV, rdev->desc->uV_step); In twl6030ldo_get_voltage, current code use below formula to calculate voltage: mV = 1000mv + 100mv * (vsel - 1) This is worng because when vsel is 0, mV is 900mV. Note the min_uV is 1000mV. Fix it by change the equation to: (This equation is common for linear mapping) return rdev->desc->min_uV + vsel * rdev->desc->uV_step; Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'drivers/regulator')
-rw-r--r--drivers/regulator/twl-regulator.c17
1 files changed, 4 insertions, 13 deletions
diff --git a/drivers/regulator/twl-regulator.c b/drivers/regulator/twl-regulator.c
index 8f0bd56c211..bb51decfcb8 100644
--- a/drivers/regulator/twl-regulator.c
+++ b/drivers/regulator/twl-regulator.c
@@ -569,30 +569,21 @@ twl6030ldo_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV,
if ((min_uV/1000 < info->min_mV) || (max_uV/1000 > info->max_mV))
return -EDOM;
- /*
- * Use the below formula to calculate vsel
- * mV = 1000mv + 100mv * (vsel - 1)
- */
- vsel = (min_uV/1000 - 1000)/100 + 1;
+ vsel = DIV_ROUND_UP(min_uV - rdev->desc->min_uV, rdev->desc->uV_step);
*selector = vsel;
- return twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE, vsel);
+ return twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE, vsel);
}
static int twl6030ldo_get_voltage(struct regulator_dev *rdev)
{
struct twlreg_info *info = rdev_get_drvdata(rdev);
- int vsel = twlreg_read(info, TWL_MODULE_PM_RECEIVER,
- VREG_VOLTAGE);
+ int vsel = twlreg_read(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE);
if (vsel < 0)
return vsel;
- /*
- * Use the below formula to calculate vsel
- * mV = 1000mv + 100mv * (vsel - 1)
- */
- return (1000 + (100 * (vsel - 1))) * 1000;
+ return rdev->desc->min_uV + vsel * rdev->desc->uV_step;
}
static struct regulator_ops twl6030ldo_ops = {