From 61d7fdc49f03f4ec990974d1d2a8b05e64afeae4 Mon Sep 17 00:00:00 2001 From: Jeffrey Hugo Date: Wed, 19 Jun 2019 11:56:36 -0700 Subject: regulator: qcom_spmi: Fix math of spmi_regulator_set_voltage_time_sel spmi_regulator_set_voltage_time_sel() calculates the amount of delay needed as the result of setting a new voltage. Essentially this is the absolute difference of the old and new voltages, divided by the slew rate. The implementation of spmi_regulator_set_voltage_time_sel() is wrong. It attempts to calculate the difference in voltages by using the difference in selectors and multiplying by the voltage step between selectors. This ignores the possibility that the old and new selectors might be from different ranges, which have different step values. Also, the difference between the selectors may encapsulate N ranges inbetween, so a summation of each selector change from old to new would be needed. Lets avoid all of that complexity, and just get the actual voltage represented by both the old and new selector, and use those to directly compute the voltage delta. This is more straight forward, and has the side benifit of avoiding issues with regulator implementations that don't have hardware register support to get the current configured range. Fixes: e92a4047419c ("regulator: Add QCOM SPMI regulator driver") Reported-by: Bjorn Andersson Reported-by: Jorge Ramirez-Ortiz Reported-by: Mark Brown Signed-off-by: Jeffrey Hugo Reviewed-by: Bjorn Andersson Tested-by: Jorge Ramirez-Ortiz Signed-off-by: Mark Brown --- drivers/regulator/qcom_spmi-regulator.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'drivers/regulator') diff --git a/drivers/regulator/qcom_spmi-regulator.c b/drivers/regulator/qcom_spmi-regulator.c index 13f83be50076..877df33e0246 100644 --- a/drivers/regulator/qcom_spmi-regulator.c +++ b/drivers/regulator/qcom_spmi-regulator.c @@ -813,14 +813,10 @@ static int spmi_regulator_set_voltage_time_sel(struct regulator_dev *rdev, unsigned int old_selector, unsigned int new_selector) { struct spmi_regulator *vreg = rdev_get_drvdata(rdev); - const struct spmi_voltage_range *range; int diff_uV; - range = spmi_regulator_find_range(vreg); - if (!range) - return -EINVAL; - - diff_uV = abs(new_selector - old_selector) * range->step_uV; + diff_uV = abs(spmi_regulator_common_list_voltage(rdev, new_selector) - + spmi_regulator_common_list_voltage(rdev, old_selector)); return DIV_ROUND_UP(diff_uV, vreg->slew_rate); } -- cgit v1.2.3