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regulator: twl: Fix the formula to calculate vsel and voltage for twl6030ldo

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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>
This commit is contained in:
Axel Lin 2012-07-09 11:22:31 +08:00 committed by Mark Brown
parent 5febb3c9d5
commit a3cb80f43a
1 changed files with 4 additions and 13 deletions
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17
drivers/regulator/twl-regulator.c
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@ -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 = {