Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935513AbcKWLTt (ORCPT ); Wed, 23 Nov 2016 06:19:49 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:1096 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932996AbcKWLTr (ORCPT ); Wed, 23 Nov 2016 06:19:47 -0500 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Wed, 23 Nov 2016 03:19:40 -0800 From: Laxman Dewangan To: , CC: , , , , Laxman Dewangan , Douglas Anderson , Aleksandr Frid Subject: [PATCH V3 2/2] regulator: Add settling time for non-linear voltage transition Date: Wed, 23 Nov 2016 16:32:40 +0530 Message-ID: <1479898960-14166-2-git-send-email-ldewangan@nvidia.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1479898960-14166-1-git-send-email-ldewangan@nvidia.com> References: <1479898960-14166-1-git-send-email-ldewangan@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3210 Lines: 83 Some regulators (some PWM regulators) have the voltage transition non-linear i.e. exponentially. On such cases, the settling time for voltage transition can not be presented in the voltage-ramp-delay. Add new property for non-linear voltage transition and handle this in getting the voltage settling time. Signed-off-by: Laxman Dewangan CC: Douglas Anderson CC: Aleksandr Frid --- This patch is continuation of discussion on patch regulator: pwm: Fix regulator ramp delay for continuous mode https://patchwork.kernel.org/patch/9216857/ where is it discussed to have separate property for PWM which has exponential voltage transition. Changes from V1: - Use new DT property to finding that voltage ramp is exponential or not and use flag for having fixed delay for all voltage change. Changes from V2: - Based on review comment from V1, make the settling time property independent of the regulator-ramp-delay and move this to core framework instead of handling in PWM regulator. --- drivers/regulator/core.c | 2 ++ drivers/regulator/of_regulator.c | 4 ++++ include/linux/regulator/machine.h | 3 +++ 3 files changed, 9 insertions(+) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 67426c0..06a2477 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -2752,6 +2752,8 @@ static int _regulator_set_voltage_time(struct regulator_dev *rdev, ramp_delay = rdev->constraints->ramp_delay; else if (rdev->desc->ramp_delay) ramp_delay = rdev->desc->ramp_delay; + else if (rdev->constraints->settling_time) + return rdev->constraints->settling_time; if (ramp_delay == 0) { rdev_warn(rdev, "ramp_delay not set\n"); diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index 4f613ec..09d677d 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -86,6 +86,10 @@ static void of_get_regulation_constraints(struct device_node *np, constraints->ramp_disable = true; } + ret = of_property_read_u32(np, "regulator-settling-time-us", &pval); + if (!ret) + constraints->settling_time = pval; + ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval); if (!ret) constraints->enable_time = pval; diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h index ad3e515..598a493 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -108,6 +108,8 @@ struct regulator_state { * @initial_state: Suspend state to set by default. * @initial_mode: Mode to set at startup. * @ramp_delay: Time to settle down after voltage change (unit: uV/us) + * @settling_time: Time to settle down after voltage change when voltage + * change is non-linear (unit: microseconds). * @active_discharge: Enable/disable active discharge. The enum * regulator_active_discharge values are used for * initialisation. @@ -149,6 +151,7 @@ struct regulation_constraints { unsigned int initial_mode; unsigned int ramp_delay; + unsigned int settling_time; unsigned int enable_time; unsigned int active_discharge; -- 2.1.4