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| author | Axel Lin <axel.lin@gmail.com> | 2012-07-09 07:22:31 +0400 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2012-07-16 01:06:05 +0400 |
| commit | a3cb80f43a9bc9b64aedd14b100e99252767d78c (patch) | |
| tree | e0e12208892082893cb80772c63bbab24a82a83b /drivers | |
| parent | 5febb3c9d52c65686a8e473a31f15137852f4b5e (diff) | |
| download | linux-a3cb80f43a9bc9b64aedd14b100e99252767d78c.tar.xz | |
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')
| -rw-r--r-- | drivers/regulator/twl-regulator.c | 17 |
1 files changed, 4 insertions, 13 deletions
diff --git a/drivers/regulator/twl-regulator.c b/drivers/regulator/twl-regulator.c index 8f0bd56c2118..bb51decfcb8e 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 = { |