Re: [PATCH RFT 1/2] regulator: twl: Fix checking voltage range in twl6030smps_set_voltage()

Rajendra Nayak
2012-07-16T09:25:26Z

Copying Graeme and linux-omap list.

On Saturday 14 July 2012 11:07 AM, Axel Lin wrote:
> The voltage selection logic is supposed to find the samllest voltage falls
> within specified range. When using equation to calculate vsel, we need to
> ensure the requested min_uV meet the range of using the equation.
> Otherwise we may select a voltage that is out of specified range.
>
> For example, in the case vsel = 62 means select voltage of 2100000uV.
> What we want is to ensure the requested min_uV<= 2100000 rather than checking
> max_uV>= 2100000. And this also means in the case min_uV> 2100000, vsel = 62
> does not meet the request.
>
> Also calling twl6030smps_list_voltage() for all cases to ensure the selected
> voltage still in bounds.
>
> Signed-off-by: Axel Lin<axel.lin@gmail.com>
> ---
> drivers/regulator/twl-regulator.c | 36 ++++++++++++++++--------------------
> 1 file changed, 16 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/regulator/twl-regulator.c b/drivers/regulator/twl-regulator.c
> index 8f0bd56..03d0bea 100644
> --- a/drivers/regulator/twl-regulator.c
> +++ b/drivers/regulator/twl-regulator.c
> @@ -760,32 +760,28 @@ twl6030smps_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV,
> unsigned int *selector)
> {
> struct twlreg_info *info = rdev_get_drvdata(rdev);
> - int vsel = 0;
> + int vsel = 0, calc_uV;
>
> switch (info->flags) {
> case 0:
> if (min_uV == 0)
> vsel = 0;
> else if ((min_uV>= 600000)&& (min_uV<= 1300000)) {
> - int calc_uV;
> vsel = DIV_ROUND_UP(min_uV - 600000, 12500);
> vsel++;
> - calc_uV = twl6030smps_list_voltage(rdev, vsel);
> - if (calc_uV> max_uV)
> - return -EINVAL;
> }
> /* Values 1..57 for vsel are linear and can be calculated
> * values 58..62 are non linear.
> */
> - else if ((min_uV> 1900000)&& (max_uV>= 2100000))
> + else if ((min_uV> 1900000)&& (min_uV<= 2100000))
> vsel = 62;
> - else if ((min_uV> 1800000)&& (max_uV>= 1900000))
> + else if ((min_uV> 1800000)&& (min_uV<= 1900000))
> vsel = 61;
> - else if ((min_uV> 1500000)&& (max_uV>= 1800000))
> + else if ((min_uV> 1500000)&& (min_uV<= 1800000))
> vsel = 60;
> - else if ((min_uV> 1350000)&& (max_uV>= 1500000))
> + else if ((min_uV> 1350000)&& (min_uV<= 1500000))
> vsel = 59;
> - else if ((min_uV> 1300000)&& (max_uV>= 1350000))
> + else if ((min_uV> 1300000)&& (min_uV<= 1350000))
> vsel = 58;
> else
> return -EINVAL;
> @@ -794,25 +790,21 @@ twl6030smps_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV,
> if (min_uV == 0)
> vsel = 0;
> else if ((min_uV>= 700000)&& (min_uV<= 1420000)) {
> - int calc_uV;
> vsel = DIV_ROUND_UP(min_uV - 700000, 12500);
> vsel++;
> - calc_uV = twl6030smps_list_voltage(rdev, vsel);
> - if (calc_uV> max_uV)
> - return -EINVAL;
> }
> /* Values 1..57 for vsel are linear and can be calculated
> * values 58..62 are non linear.
> */
> - else if ((min_uV> 1900000)&& (max_uV>= 2100000))
> + else if ((min_uV> 1900000)&& (min_uV<= 2100000))
> vsel = 62;
> - else if ((min_uV> 1800000)&& (max_uV>= 1900000))
> + else if ((min_uV> 1800000)&& (min_uV<= 1900000))
> vsel = 61;
> - else if ((min_uV> 1350000)&& (max_uV>= 1800000))
> + else if ((min_uV> 1350000)&& (min_uV<= 1800000))
> vsel = 60;
> - else if ((min_uV> 1350000)&& (max_uV>= 1500000))
> + else if ((min_uV> 1350000)&& (min_uV<= 1500000))
> vsel = 59;
> - else if ((min_uV> 1300000)&& (max_uV>= 1350000))
> + else if ((min_uV> 1300000)&& (min_uV<= 1350000))
> vsel = 58;
> else
> return -EINVAL;
> @@ -828,13 +820,17 @@ twl6030smps_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV,
> case SMPS_OFFSET_EN|SMPS_EXTENDED_EN:
> if (min_uV == 0) {
> vsel = 0;
> - } else if ((min_uV>= 2161000)&& (max_uV<= 4321000)) {
> + } else if ((min_uV>= 2161000)&& (min_uV<= 4321000)) {
> vsel = DIV_ROUND_UP(min_uV - 2161000, 38600);
> vsel++;
> }
> break;
> }
>
> + calc_uV = twl6030smps_list_voltage(rdev, vsel);
> + if (calc_uV> max_uV)
> + return -EINVAL;
> +
> *selector = vsel;
>
> return twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE_SMPS,