From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751628AbdKBFGY (ORCPT ); Thu, 2 Nov 2017 01:06:24 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:59220 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750836AbdKBFGW (ORCPT ); Thu, 2 Nov 2017 01:06:22 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org E61D260285 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sboyd@codeaurora.org From: Stephen Boyd To: Mark Brown Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org Subject: [PATCH] regulator: qcom_spmi: Include offset when translating voltages Date: Wed, 1 Nov 2017 22:06:19 -0700 Message-Id: <20171102050619.32204-1-sboyd@codeaurora.org> X-Mailer: git-send-email 2.15.0.rc0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This driver converts voltages from a non-linear range in hardware to a linear range in software and vice versa. During the conversion, we exclude certain voltages that are invalid to use because the software interface is more flexible than reality. For example, the FTSMPS2P5 regulators have a voltage range from 80000uV to 1355000uV that software could support, but we only want to use the range of 350000uV to 1355000uV. If we don't account for the hw selectors between 80000uV and 350000uV we'll pick a hw selector of 0 to mean 350000uV when it really means 80000uV. This can cause us to program voltages into the hardware that are significantly lower than what we're expecting. And when we read it back from the hardware we'll have the same problem, voltages that are in the invalid band will end up being calculated as some software selector that represents a larger voltage than what is programmed and the user will be confused. Fix all this by properly offsetting the software selector and hw selector when converting from one number space to another. Fixes: 1b5b19689278 ("regulator: qcom_spmi: Only use selector based regulator ops") Signed-off-by: Stephen Boyd --- drivers/regulator/qcom_spmi-regulator.c | 39 ++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 6 deletions(-) diff --git a/drivers/regulator/qcom_spmi-regulator.c b/drivers/regulator/qcom_spmi-regulator.c index 16c5f84e06a7..c372b244f3da 100644 --- a/drivers/regulator/qcom_spmi-regulator.c +++ b/drivers/regulator/qcom_spmi-regulator.c @@ -593,13 +593,20 @@ static int spmi_sw_selector_to_hw(struct spmi_regulator *vreg, u8 *voltage_sel) { const struct spmi_voltage_range *range, *end; + unsigned offset; range = vreg->set_points->range; end = range + vreg->set_points->count; for (; range < end; range++) { if (selector < range->n_voltages) { - *voltage_sel = selector; + /* + * hardware selectors between set point min and real + * min are invalid so we ignore them + */ + offset = range->set_point_min_uV - range->min_uV; + offset /= range->step_uV; + *voltage_sel = selector + offset; *range_sel = range->range_sel; return 0; } @@ -613,15 +620,35 @@ static int spmi_sw_selector_to_hw(struct spmi_regulator *vreg, static int spmi_hw_selector_to_sw(struct spmi_regulator *vreg, u8 hw_sel, const struct spmi_voltage_range *range) { - int sw_sel = hw_sel; + unsigned sw_sel = 0; + unsigned offset, max_hw_sel; const struct spmi_voltage_range *r = vreg->set_points->range; - - while (r != range) { + const struct spmi_voltage_range *end = r + vreg->set_points->count; + + for (; r < end; r++) { + if (r == range && range->n_voltages) { + /* + * hardware selectors between set point min and real + * min and between set point max and real max are + * invalid so we return an error if they're + * programmed into the hardware + */ + offset = range->set_point_min_uV - range->min_uV; + offset /= range->step_uV; + if (hw_sel < offset) + return -EINVAL; + + max_hw_sel = range->set_point_max_uV - range->min_uV; + max_hw_sel /= range->step_uV; + if (hw_sel > max_hw_sel) + return -EINVAL; + + return sw_sel + hw_sel - offset; + } sw_sel += r->n_voltages; - r++; } - return sw_sel; + return -EINVAL; } static const struct spmi_voltage_range * -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project