From patchwork Tue Jun 14 09:13:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Brezillon X-Patchwork-Id: 635116 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3rTPBS646Hz9t16 for ; Tue, 14 Jun 2016 19:15:28 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752254AbcFNJOo (ORCPT ); Tue, 14 Jun 2016 05:14:44 -0400 Received: from down.free-electrons.com ([37.187.137.238]:59619 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752101AbcFNJNf (ORCPT ); Tue, 14 Jun 2016 05:13:35 -0400 Received: by mail.free-electrons.com (Postfix, from userid 110) id 419F7A25; Tue, 14 Jun 2016 11:13:33 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on mail.free-electrons.com X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,SHORTCIRCUIT, URIBL_BLOCKED shortcircuit=ham autolearn=disabled version=3.4.0 Received: from bbrezillon.home (LStLambert-657-1-97-87.w90-63.abo.wanadoo.fr [90.63.216.87]) by mail.free-electrons.com (Postfix) with ESMTPSA id 8EB224BA; Tue, 14 Jun 2016 11:13:32 +0200 (CEST) From: Boris Brezillon To: Thierry Reding , linux-pwm@vger.kernel.org, Mark Brown , Liam Girdwood Cc: Heiko Stuebner , linux-rockchip@lists.infradead.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Milo Kim , Doug Anderson , Caesar Wang , Stephen Barber , Brian Norris , Ajit Pal Singh , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , kernel@stlinux.com, Laxman Dewangan , Boris Brezillon Subject: [PATCH v3 13/14] regulator: pwm: Support extra continuous mode cases Date: Tue, 14 Jun 2016 11:13:21 +0200 Message-Id: <1465895602-31008-14-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1465895602-31008-1-git-send-email-boris.brezillon@free-electrons.com> References: <1465895602-31008-1-git-send-email-boris.brezillon@free-electrons.com> Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org The continuous mode allows one to declare a PWM regulator without having to declare the voltage <-> dutycycle association table. It works fine as long as your voltage(dutycycle) function is linear, but also has the following constraints: - dutycycle for min_uV = 0% - dutycycle for max_uV = 100% - dutycycle for min_uV < dutycycle for max_uV While the linearity constraint is acceptable for now, we sometimes need to restrict of the PWM range (to limit the maximum/minimum voltage for example) or have a min_uV_dutycycle > max_uV_dutycycle (this could be tweaked with PWM polarity, but not all PWMs support inverted polarity). Add the pwm-dutycycle-range and pwm-dutycycle-unit DT properties to define such constraints. If those properties are not defined, the PWM regulator use the default pwm-dutycycle-range = <0 100> and pwm-dutycycle-unit = <100> values (existing behavior). Signed-off-by: Boris Brezillon Reviewed-by: Brian Norris Tested-by: Brian Norris Tested-by: Heiko Stuebner Acked-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 90 +++++++++++++++++++++++++++++++++++---- 1 file changed, 81 insertions(+), 9 deletions(-) diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 80d083f..fa1c74c 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -21,6 +21,12 @@ #include #include +struct pwm_continuous_reg_data { + unsigned int min_uV_dutycycle; + unsigned int max_uV_dutycycle; + unsigned int dutycycle_unit; +}; + struct pwm_regulator_data { /* Shared */ struct pwm_device *pwm; @@ -28,6 +34,9 @@ struct pwm_regulator_data { /* Voltage table */ struct pwm_voltages *duty_cycle_table; + /* Continuous mode info */ + struct pwm_continuous_reg_data continuous; + /* regulator descriptor */ struct regulator_desc desc; @@ -132,31 +141,77 @@ static int pwm_regulator_is_enabled(struct regulator_dev *dev) static int pwm_regulator_get_voltage(struct regulator_dev *rdev) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle; + unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle; + unsigned int duty_unit = drvdata->continuous.dutycycle_unit; int min_uV = rdev->constraints->min_uV; - int diff = rdev->constraints->max_uV - min_uV; + int max_uV = rdev->constraints->max_uV; + int diff_uV = max_uV - min_uV; struct pwm_state pstate; + unsigned int diff_duty; + unsigned int voltage; pwm_get_state(drvdata->pwm, &pstate); - return min_uV + pwm_get_relative_duty_cycle(&pstate, diff); + voltage = pwm_get_relative_duty_cycle(&pstate, duty_unit); + + /* + * The dutycycle for min_uV might be greater than the one for max_uV. + * This is happening when the user needs an inversed polarity, but the + * PWM device does not support inversing it in hardware. + */ + if (max_uV_duty < min_uV_duty) { + voltage = min_uV_duty - voltage; + diff_duty = min_uV_duty - max_uV_duty; + } else { + voltage = voltage - min_uV_duty; + diff_duty = max_uV_duty - min_uV_duty; + } + + voltage = DIV_ROUND_CLOSEST_ULL((u64)voltage * diff_uV, diff_duty); + + return voltage + min_uV; } static int pwm_regulator_set_voltage(struct regulator_dev *rdev, - int min_uV, int max_uV, - unsigned *selector) + int req_min_uV, int req_max_uV, + unsigned int *selector) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle; + unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle; + unsigned int duty_unit = drvdata->continuous.dutycycle_unit; unsigned int ramp_delay = rdev->constraints->ramp_delay; - unsigned int req_diff = min_uV - rdev->constraints->min_uV; + int min_uV = rdev->constraints->min_uV; + int max_uV = rdev->constraints->max_uV; + int diff_uV = max_uV - min_uV; struct pwm_state pstate; - unsigned int diff; + unsigned int diff_duty; + unsigned int dutycycle; int ret; pwm_init_state(drvdata->pwm, &pstate); - diff = rdev->constraints->max_uV - rdev->constraints->min_uV; - /* We pass diff as the scale to get a uV precision. */ - pwm_set_relative_duty_cycle(&pstate, req_diff, diff); + /* + * The dutycycle for min_uV might be greater than the one for max_uV. + * This is happening when the user needs an inversed polarity, but the + * PWM device does not support inversing it in hardware. + */ + if (max_uV_duty < min_uV_duty) + diff_duty = min_uV_duty - max_uV_duty; + else + diff_duty = max_uV_duty - min_uV_duty; + + dutycycle = DIV_ROUND_CLOSEST_ULL((u64)(req_min_uV - min_uV) * + diff_duty, + diff_uV); + + if (max_uV_duty < min_uV_duty) + dutycycle = min_uV_duty - dutycycle; + else + dutycycle = min_uV_duty + dutycycle; + + pwm_set_relative_duty_cycle(&pstate, dutycycle, duty_unit); ret = pwm_apply_state(drvdata->pwm, &pstate); if (ret) { @@ -237,11 +292,28 @@ static int pwm_regulator_init_table(struct platform_device *pdev, static int pwm_regulator_init_continuous(struct platform_device *pdev, struct pwm_regulator_data *drvdata) { + u32 dutycycle_range[2] = { 0, 100 }; + u32 dutycycle_unit = 100; + memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops, sizeof(drvdata->ops)); drvdata->desc.ops = &drvdata->ops; drvdata->desc.continuous_voltage_range = true; + of_property_read_u32_array(pdev->dev.of_node, + "pwm-dutycycle-range", + dutycycle_range, 2); + of_property_read_u32(pdev->dev.of_node, "pwm-dutycycle-unit", + &dutycycle_unit); + + if (dutycycle_range[0] > dutycycle_unit || + dutycycle_range[1] > dutycycle_unit) + return -EINVAL; + + drvdata->continuous.dutycycle_unit = dutycycle_unit; + drvdata->continuous.min_uV_dutycycle = dutycycle_range[0]; + drvdata->continuous.max_uV_dutycycle = dutycycle_range[1]; + return 0; }