From: Stephen Warren <swarren@wwwdotorg.org>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: Rob Herring <rob.herring@calxeda.com>,
Pawel Moll <pawel.moll@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Tony Lindgren <tony@atomide.com>,
Eric Miao <eric.y.miao@gmail.com>,
Haojian Zhuang <haojian.zhuang@gmail.com>,
Ben Dooks <ben-linux@fluff.org>,
Kukjin Kim <kgene.kim@samsung.com>,
Simon Horman <horms@verge.net.au>,
Magnus Damm <magnus.damm@gmail.com>,
Guan Xuetao <gxt@mprc.pku.edu.cn>,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-omap@vger.kernel.org, openezx-devel@lists.openezx.org,
linux-samsung-soc@vger.kernel.org, linux-sh@vger.kernel.org,
linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 09/10] pwm-backlight: Use an optional power supply
Date: Tue, 01 Oct 2013 12:43:57 -0600 [thread overview]
Message-ID: <524B17ED.1080806@wwwdotorg.org> (raw)
In-Reply-To: <1379972467-11243-10-git-send-email-treding@nvidia.com>
On 09/23/2013 03:41 PM, Thierry Reding wrote:
> Many backlights require a power supply to work properly. This commit
> uses a power-supply regulator, if available, to power up and power down
> the panel.
I think that all backlights require a power supply, albeit the supply
may not be SW-controllable. Hence, shouldn't the regulator be mandatory
in the binding, yet the driver be defensively coded such that if one
isn't specified, the driver continues to work?
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> @@ -253,6 +264,16 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> }
> }
>
> + pb->power_supply = devm_regulator_get_optional(&pdev->dev, "power");
... so I think that should be devm_regulator_get(), since the regulator
isn't really optional.
> + if (IS_ERR(pb->power_supply)) {
> + if (PTR_ERR(pb->power_supply) != -ENODEV) {
> + ret = PTR_ERR(pb->power_supply);
> + goto err_gpio;
> + }
> +
> + pb->power_supply = NULL;
If devm_regulator_get_optional() returns an error value or a valid
value, then I don't think that this driver should transmute error values
into NULL; NULL might be a perfectly valid regulator value. Related, I
think the if (pb->power_supply) tests should be replaced with if
(!IS_ERR(pb->power_supply)) instead.
WARNING: multiple messages have this Message-ID (diff)
From: Stephen Warren <swarren@wwwdotorg.org>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 09/10] pwm-backlight: Use an optional power supply
Date: Tue, 01 Oct 2013 18:43:57 +0000 [thread overview]
Message-ID: <524B17ED.1080806@wwwdotorg.org> (raw)
In-Reply-To: <1379972467-11243-10-git-send-email-treding@nvidia.com>
On 09/23/2013 03:41 PM, Thierry Reding wrote:
> Many backlights require a power supply to work properly. This commit
> uses a power-supply regulator, if available, to power up and power down
> the panel.
I think that all backlights require a power supply, albeit the supply
may not be SW-controllable. Hence, shouldn't the regulator be mandatory
in the binding, yet the driver be defensively coded such that if one
isn't specified, the driver continues to work?
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> @@ -253,6 +264,16 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> }
> }
>
> + pb->power_supply = devm_regulator_get_optional(&pdev->dev, "power");
... so I think that should be devm_regulator_get(), since the regulator
isn't really optional.
> + if (IS_ERR(pb->power_supply)) {
> + if (PTR_ERR(pb->power_supply) != -ENODEV) {
> + ret = PTR_ERR(pb->power_supply);
> + goto err_gpio;
> + }
> +
> + pb->power_supply = NULL;
If devm_regulator_get_optional() returns an error value or a valid
value, then I don't think that this driver should transmute error values
into NULL; NULL might be a perfectly valid regulator value. Related, I
think the if (pb->power_supply) tests should be replaced with if
(!IS_ERR(pb->power_supply)) instead.
WARNING: multiple messages have this Message-ID (diff)
From: swarren@wwwdotorg.org (Stephen Warren)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 09/10] pwm-backlight: Use an optional power supply
Date: Tue, 01 Oct 2013 12:43:57 -0600 [thread overview]
Message-ID: <524B17ED.1080806@wwwdotorg.org> (raw)
In-Reply-To: <1379972467-11243-10-git-send-email-treding@nvidia.com>
On 09/23/2013 03:41 PM, Thierry Reding wrote:
> Many backlights require a power supply to work properly. This commit
> uses a power-supply regulator, if available, to power up and power down
> the panel.
I think that all backlights require a power supply, albeit the supply
may not be SW-controllable. Hence, shouldn't the regulator be mandatory
in the binding, yet the driver be defensively coded such that if one
isn't specified, the driver continues to work?
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> @@ -253,6 +264,16 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> }
> }
>
> + pb->power_supply = devm_regulator_get_optional(&pdev->dev, "power");
... so I think that should be devm_regulator_get(), since the regulator
isn't really optional.
> + if (IS_ERR(pb->power_supply)) {
> + if (PTR_ERR(pb->power_supply) != -ENODEV) {
> + ret = PTR_ERR(pb->power_supply);
> + goto err_gpio;
> + }
> +
> + pb->power_supply = NULL;
If devm_regulator_get_optional() returns an error value or a valid
value, then I don't think that this driver should transmute error values
into NULL; NULL might be a perfectly valid regulator value. Related, I
think the if (pb->power_supply) tests should be replaced with if
(!IS_ERR(pb->power_supply)) instead.
next prev parent reply other threads:[~2013-10-01 18:44 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-23 21:40 [PATCH 00/10] pwm-backlight: Add GPIO and power supply support Thierry Reding
2013-09-23 21:40 ` Thierry Reding
2013-09-23 21:40 ` Thierry Reding
2013-09-23 21:40 ` [PATCH 01/10] pwm-backlight: Refactor backlight power on/off Thierry Reding
2013-09-23 21:40 ` Thierry Reding
2013-09-23 21:40 ` Thierry Reding
2013-09-23 21:40 ` Thierry Reding
[not found] ` <1379972467-11243-2-git-send-email-treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2013-10-01 18:26 ` Stephen Warren
2013-10-01 18:26 ` Stephen Warren
2013-10-01 18:26 ` Stephen Warren
2013-10-01 18:26 ` Stephen Warren
2013-10-01 20:34 ` Thierry Reding
2013-10-01 20:34 ` Thierry Reding
2013-10-01 20:34 ` Thierry Reding
2013-09-23 21:40 ` [PATCH 02/10] pwm-backlight: Add optional enable GPIO Thierry Reding
2013-09-23 21:40 ` Thierry Reding
2013-09-23 21:40 ` Thierry Reding
2013-09-23 21:41 ` [PATCH 03/10] ARM: OMAP: Initialize PWM backlight enable_gpio field Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` [PATCH 04/10] ARM: pxa: " Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` [PATCH 05/10] ARM: SAMSUNG: " Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-10-01 18:31 ` Stephen Warren
2013-10-01 18:31 ` Stephen Warren
2013-10-01 18:31 ` Stephen Warren
[not found] ` <524B14E8.5040302-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2013-10-01 20:43 ` Thierry Reding
2013-10-01 20:43 ` Thierry Reding
2013-10-01 20:43 ` Thierry Reding
2013-10-01 20:43 ` Thierry Reding
[not found] ` <20131001204335.GB9201-AwZRO8vwLAwmlAP/+Wk3EA@public.gmane.org>
2013-10-01 20:58 ` Stephen Warren
2013-10-01 20:58 ` Stephen Warren
2013-10-01 20:58 ` Stephen Warren
2013-10-01 20:58 ` Stephen Warren
2013-10-01 21:23 ` Thierry Reding
2013-10-01 21:23 ` Thierry Reding
2013-10-01 21:23 ` Thierry Reding
2013-09-23 21:41 ` [PATCH 06/10] ARM: shmobile: " Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-25 5:40 ` Simon Horman
2013-09-25 5:40 ` Simon Horman
2013-09-25 5:40 ` Simon Horman
2013-09-23 21:41 ` [PATCH 07/10] unicore32: " Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
[not found] ` <1379972467-11243-1-git-send-email-treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2013-09-23 21:41 ` [PATCH 08/10] pwm-backlight: Use new " Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
[not found] ` <1379972467-11243-9-git-send-email-treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2013-10-01 18:39 ` Stephen Warren
2013-10-01 18:39 ` Stephen Warren
2013-10-01 18:39 ` Stephen Warren
2013-10-01 18:39 ` Stephen Warren
2013-10-01 20:49 ` Thierry Reding
2013-10-01 20:49 ` Thierry Reding
2013-10-01 20:49 ` Thierry Reding
2013-09-23 21:41 ` [PATCH 09/10] pwm-backlight: Use an optional power supply Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-10-01 18:43 ` Stephen Warren [this message]
2013-10-01 18:43 ` Stephen Warren
2013-10-01 18:43 ` Stephen Warren
2013-10-01 20:53 ` Thierry Reding
2013-10-01 20:53 ` Thierry Reding
2013-10-01 20:53 ` Thierry Reding
2013-10-01 20:59 ` Stephen Warren
2013-10-01 20:59 ` Stephen Warren
2013-10-01 20:59 ` Stephen Warren
2013-10-01 21:31 ` Thierry Reding
2013-10-01 21:31 ` Thierry Reding
2013-10-01 21:31 ` Thierry Reding
2013-10-02 10:35 ` Mark Brown
2013-10-02 10:35 ` Mark Brown
2013-10-02 10:35 ` Mark Brown
2013-09-23 21:41 ` [PATCH 10/10] pwm-backlight: Allow backlight to remain disabled on boot Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-09-23 21:41 ` Thierry Reding
2013-10-01 18:50 ` Stephen Warren
2013-10-01 18:50 ` Stephen Warren
2013-10-01 18:50 ` Stephen Warren
2013-10-01 21:14 ` Thierry Reding
2013-10-01 21:14 ` Thierry Reding
2013-10-01 21:14 ` Thierry Reding
2013-10-02 17:45 ` Thierry Reding
2013-10-02 17:45 ` Thierry Reding
2013-10-02 17:45 ` Thierry Reding
2013-09-24 8:14 ` [PATCH 00/10] pwm-backlight: Add GPIO and power supply support Simon Horman
2013-09-24 8:14 ` Simon Horman
2013-09-24 8:14 ` Simon Horman
[not found] ` <20130924081446.GA11981-/R6kz+dDXgpPR4JQBCEnsQ@public.gmane.org>
2013-09-24 9:00 ` Thierry Reding
2013-09-24 9:00 ` Thierry Reding
2013-09-24 9:00 ` Thierry Reding
2013-09-24 9:00 ` Thierry Reding
2013-09-25 5:39 ` Simon Horman
2013-09-25 5:39 ` Simon Horman
2013-09-25 5:39 ` Simon Horman
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