From patchwork Wed Jan 13 09:22:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 1425704 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=tkos.co.il Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DG27t3LZCz9sVs for ; Wed, 13 Jan 2021 20:24:10 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726288AbhAMJYI (ORCPT ); Wed, 13 Jan 2021 04:24:08 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:45692 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbhAMJYH (ORCPT ); Wed, 13 Jan 2021 04:24:07 -0500 Received: from tarshish.tkos.co.il (unknown [10.0.8.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPS id 0A30844045F; Wed, 13 Jan 2021 11:23:25 +0200 (IST) From: Baruch Siach To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Lee Jones , Linus Walleij , Bartosz Golaszewski Cc: Baruch Siach , Russell King , Andrew Lunn , Gregory Clement , Sebastian Hesselbarth , Thomas Petazzoni , Chris Packham , Sascha Hauer , Ralph Sennhauser , linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 1/5] gpio: mvebu: fix pwm .get_state period calculation Date: Wed, 13 Jan 2021 11:22:41 +0200 Message-Id: <57860e4929a9d20d73f5e003a148b86a9f82310e.1610529002.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org The period is the sum of on and off values. That is, calculate period as ($on + $off) / clkrate instead of $off / clkrate - $on / clkrate that makes no sense. Reported-by: Russell King Fixes: 757642f9a584e ("gpio: mvebu: Add limited PWM support") Signed-off-by: Baruch Siach Reviewed-by: Uwe Kleine-König --- drivers/gpio/gpio-mvebu.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index 672681a976f5..a912a8fed197 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -676,20 +676,17 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, else state->duty_cycle = 1; + val = (unsigned long long) u; /* on duration */ regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u); - val = (unsigned long long) u * NSEC_PER_SEC; + val += (unsigned long long) u; /* period = on + off duration */ + val *= NSEC_PER_SEC; do_div(val, mvpwm->clk_rate); - if (val < state->duty_cycle) { + if (val > UINT_MAX) + state->period = UINT_MAX; + else if (val) + state->period = val; + else state->period = 1; - } else { - val -= state->duty_cycle; - if (val > UINT_MAX) - state->period = UINT_MAX; - else if (val) - state->period = val; - else - state->period = 1; - } regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u); if (u) From patchwork Wed Jan 13 09:22:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 1425708 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=tkos.co.il Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DG27v744Lz9sWC for ; Wed, 13 Jan 2021 20:24:11 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726784AbhAMJYI (ORCPT ); Wed, 13 Jan 2021 04:24:08 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:45702 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726207AbhAMJYI (ORCPT ); Wed, 13 Jan 2021 04:24:08 -0500 Received: from tarshish.tkos.co.il (unknown [10.0.8.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPS id BB8AE44056C; Wed, 13 Jan 2021 11:23:25 +0200 (IST) From: Baruch Siach To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Lee Jones , Linus Walleij , Bartosz Golaszewski Cc: Baruch Siach , Andrew Lunn , Gregory Clement , Russell King , Sebastian Hesselbarth , Thomas Petazzoni , Chris Packham , Sascha Hauer , Ralph Sennhauser , linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 2/5] gpio: mvebu: improve pwm period calculation accuracy Date: Wed, 13 Jan 2021 11:22:42 +0200 Message-Id: <8be9177df5081ccfbbb5ec6e2fabf5937801f453.1610529002.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Change 'off' register value calculation from $off = (period - duty_cycle) * clkrate / NSEC_PER_SEC to $off = (period * clkrate / NSEC_PER_SEC) - $on That is, divide the full period value to reduce rounding error. Reported-by: Uwe Kleine-König Reviewed-by: Uwe Kleine-König Signed-off-by: Baruch Siach --- drivers/gpio/gpio-mvebu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index a912a8fed197..c424d88e9e2b 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -715,9 +715,9 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, else on = 1; - val = (unsigned long long) mvpwm->clk_rate * - (state->period - state->duty_cycle); + val = (unsigned long long) mvpwm->clk_rate * state->period; do_div(val, NSEC_PER_SEC); + val -= on; if (val > UINT_MAX) return -EINVAL; if (val) From patchwork Wed Jan 13 09:22:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 1425710 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=tkos.co.il Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DG27w6Gypz9sVs for ; Wed, 13 Jan 2021 20:24:12 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726788AbhAMJYJ (ORCPT ); Wed, 13 Jan 2021 04:24:09 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:45713 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726381AbhAMJYJ (ORCPT ); Wed, 13 Jan 2021 04:24:09 -0500 Received: from tarshish.tkos.co.il (unknown [10.0.8.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPS id 9CFD14405AD; Wed, 13 Jan 2021 11:23:26 +0200 (IST) From: Baruch Siach To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Lee Jones , Linus Walleij , Bartosz Golaszewski Cc: Baruch Siach , Andrew Lunn , Gregory Clement , Russell King , Sebastian Hesselbarth , Thomas Petazzoni , Chris Packham , Sascha Hauer , Ralph Sennhauser , linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 3/5] gpio: mvebu: make pwm .get_state closer to idempotent Date: Wed, 13 Jan 2021 11:22:43 +0200 Message-Id: <1d376a3500e11d8fd2ecaf9ca345977f011079af.1610529002.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Round up the result of division in period/duty_cycle calculation to make the result closer to idempotent. Reported-by: Uwe Kleine-König Signed-off-by: Baruch Siach Reviewed-by: Uwe Kleine-König --- drivers/gpio/gpio-mvebu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index c424d88e9e2b..8673ba77af5a 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -668,7 +668,7 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), &u); val = (unsigned long long) u * NSEC_PER_SEC; - do_div(val, mvpwm->clk_rate); + val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate); if (val > UINT_MAX) state->duty_cycle = UINT_MAX; else if (val) @@ -680,7 +680,7 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u); val += (unsigned long long) u; /* period = on + off duration */ val *= NSEC_PER_SEC; - do_div(val, mvpwm->clk_rate); + val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate); if (val > UINT_MAX) state->period = UINT_MAX; else if (val) From patchwork Wed Jan 13 09:22:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 1425712 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=tkos.co.il Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DG27x4SPRz9sWH for ; Wed, 13 Jan 2021 20:24:13 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726381AbhAMJYK (ORCPT ); Wed, 13 Jan 2021 04:24:10 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:45725 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726207AbhAMJYK (ORCPT ); Wed, 13 Jan 2021 04:24:10 -0500 Received: from tarshish.tkos.co.il (unknown [10.0.8.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPS id 8371944064A; Wed, 13 Jan 2021 11:23:27 +0200 (IST) From: Baruch Siach To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Lee Jones , Linus Walleij , Bartosz Golaszewski Cc: Baruch Siach , Andrew Lunn , Gregory Clement , Russell King , Sebastian Hesselbarth , Thomas Petazzoni , Chris Packham , Sascha Hauer , Ralph Sennhauser , linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 4/5] gpio: mvebu: don't limit pwm period/duty_cycle to UINT_MAX Date: Wed, 13 Jan 2021 11:22:44 +0200 Message-Id: <36689bd45594c83338e876a502984626d5a55262.1610529002.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org PWM on/off registers are limited to UINT_MAX. However the state period and duty_cycle fields are ns values of type u64. There is no reason to limit them to UINT_MAX. Reported-by: Uwe Kleine-König Reviewed-by: Uwe Kleine-König Signed-off-by: Baruch Siach --- drivers/gpio/gpio-mvebu.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index 8673ba77af5a..6b017854ce61 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -669,9 +669,7 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), &u); val = (unsigned long long) u * NSEC_PER_SEC; val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate); - if (val > UINT_MAX) - state->duty_cycle = UINT_MAX; - else if (val) + if (val) state->duty_cycle = val; else state->duty_cycle = 1; @@ -681,9 +679,7 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, val += (unsigned long long) u; /* period = on + off duration */ val *= NSEC_PER_SEC; val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate); - if (val > UINT_MAX) - state->period = UINT_MAX; - else if (val) + if (val) state->period = val; else state->period = 1; From patchwork Wed Jan 13 09:22:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 1425715 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=tkos.co.il Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DG28y3FGBz9sWH for ; Wed, 13 Jan 2021 20:25:06 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726868AbhAMJYu (ORCPT ); Wed, 13 Jan 2021 04:24:50 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:45745 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726828AbhAMJYt (ORCPT ); Wed, 13 Jan 2021 04:24:49 -0500 Received: from tarshish.tkos.co.il (unknown [10.0.8.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPS id 5F0DD4407B2; Wed, 13 Jan 2021 11:23:28 +0200 (IST) From: Baruch Siach To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Lee Jones , Linus Walleij , Bartosz Golaszewski Cc: Baruch Siach , Russell King , Andrew Lunn , Gregory Clement , Sebastian Hesselbarth , Thomas Petazzoni , Chris Packham , Sascha Hauer , Ralph Sennhauser , linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 5/5] gpio: mvebu: document zero pwm duty cycle limitation Date: Wed, 13 Jan 2021 11:22:45 +0200 Message-Id: <08fb30de22864ecfecf6f9bc59ca78a61a34b3fd.1610529002.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Add a comment on why the code never sets on/off registers to zero. Reported-by: Uwe Kleine-König Analyzed-by: Russell King Signed-off-by: Baruch Siach --- drivers/gpio/gpio-mvebu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index 6b017854ce61..09780944bef9 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -706,6 +706,10 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, do_div(val, NSEC_PER_SEC); if (val > UINT_MAX) return -EINVAL; + /* + * Zero on/off values don't work as expected. Experimentation shows + * that zero value is treated as 2^32. This behavior is not documented. + */ if (val) on = val; else