From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout.gmx.net (mout.gmx.net [212.227.17.21]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 46387111BC; Mon, 5 Feb 2024 07:08:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.17.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707116932; cv=none; b=twXrQ5z2ncEbhNQkn5QHDfyL1hmPU43l1nQJa9EMXvM1wRLwxwNTYTy4IbkyVY0s9kpnofmTD7yAbmGbvBulQo+EWHy6nxtvOSyc5lXy90dpdAhwfZDsEbf06cwBcISAsBAL/BNVxp0BP0KjaiER8Zxi9vtXoBHLStOr030Ss7A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707116932; c=relaxed/simple; bh=5D6PtR3PJDZbVWih7S47g7THCBU4Tdd43oQC93fiPz8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rItyCPrxqLR3ea8RKI6VmKmfEUBCCRuLMHMdsLFWvrCG1rcWFFaLE9KmNwlgOmH3H4om7e6RBrxI7Pk9TXSvVHxUnJPuNhqBckJLLoLutEuQZhKcL86diuo2b0Zi2HrT6NHlnFmmpO/lkrhrX7kiuTx4lSzxYs76cD2Yb87GHpg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.net; spf=pass smtp.mailfrom=gmx.net; dkim=pass (2048-bit key) header.d=gmx.net header.i=wahrenst@gmx.net header.b=WQvenkna; arc=none smtp.client-ip=212.227.17.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.net header.i=wahrenst@gmx.net header.b="WQvenkna" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=s31663417; t=1707116916; x=1707721716; i=wahrenst@gmx.net; bh=5D6PtR3PJDZbVWih7S47g7THCBU4Tdd43oQC93fiPz8=; h=X-UI-Sender-Class:Date:Subject:To:Cc:References:From: In-Reply-To; b=WQvenknafKo3CcXWBx0dsgNVjWyqHdjdRKNjWkeG8+F9vOgvfXOqNgD9zl8/S5xW qtM3qL0zPj/KvP94PqYxie7STbgb40oaFBwTFCvwKWzfGfSmXmaenmkYjRtB4kF8E eupSxKu4t40mN8VsUkTSYrAV+S2RkjhV1BJ+vVuHtWOIXR33papx5EEHeccb2AHux FQGNHBAscswuAJfV0Nv9iMg7DRu81V+4pPkPSFt1gYPeS+1c2jumEUVMU365NUJf6 YiSTpGNCxYDJFxH1tmfIJ2cegfm4CC58GvxwG/dyTI5mixz/d5m8UTSNt/R9NX2OR ZpvBNFDIRhe+VxMERg== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [192.168.1.167] ([37.4.248.43]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MFsUp-1roG9z1eF5-00HKm8; Mon, 05 Feb 2024 08:08:36 +0100 Message-ID: Date: Mon, 5 Feb 2024 08:08:35 +0100 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V4 0/2] pwm: Add GPIO PWM driver To: Dhruva Gole Cc: =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= , Rob Herring , Krzysztof Kozlowski , Conor Dooley , andy.shevchenko@gmail.com, Angelo Compagnucci , Philip Howard , Sean Young , Linus Walleij , linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org References: <20240204220851.4783-1-wahrenst@gmx.net> <20240205055514.rox6yd2eenhsngva@dhruva> Content-Language: en-US From: Stefan Wahren In-Reply-To: <20240205055514.rox6yd2eenhsngva@dhruva> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:WHZhsobmTrrWP/5xMIm81jeJJO6MCzdgFLH0Ivd2cn2MPrTRd7v D5zlbAyhGfc1Ht5zsYFNkZljXrngWCxY3O9G8FcOhOeKQeOmAp7hz0bDs4OtqWnbi5/Fr4p rutjaYEKxCbEGy8igrOIrl2LC+HdEWBGDCss/sLp90wXWQFWxwI/KbSvDMvZKEvxOTtt3hK 9I6b0QtF13RNAFNd+47sg== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:pbrHxWqgucI=;3xkW4gYjLZ2bqxvcBySP1SbCLat BSpdDgF5GsO48TyCPP3cvG5VmpSmLxHDgS7+VsVV1gxkMhN8vEAY95l4Gi5YGYYhwtxubcx3s bqkMW/0iFpl4dvvhSQo+WANWknaP5X2w8uRUbjls0tXBYptbL6OPNLSXj0wNJFKhrhZVphw/0 BnQPM5uM8w1aO19whPQmhfErVDs2C09dokwpbMbE3ePYHfebSK1Iv6XSeccAMhY2S1KpKg6js vS/xOZ7cOJ7JrjiEurOkM8/fRJnqaok+vtON+DtuSPr+2ixrePC3kla6j++BEbc0OehnAxXRK HXq2TSiMmO2mmPSx3475COXaEXkZeO0egqsK+w8iIAM+s7X20H7f1PBuBuMg9VtVo1s/XIRjJ ZsL8JuVyv5wBU2izFojON788vvWe+hBYpft44wAiWItq6XQBMlpZSLUmXQUK9IDzZANYf1FqP r/KazvuvcZcGSWjlZ6oxPjVx4rS9X33Ckrd+1JA91Vej+ANtx0ckjvrEn9VnwJtxrqUpvSBVY /Ms34AT2ZrCKYgIpVVSIu744qeMquthSErUnCVN/w/KPDeXsybXvf/YeHho7Yp4pJ7JLMkJEY cE5ZCbpYj8VLgOI4VUDbRotfxkFKQA0uC4VOnkFbANMuSpyZgrDsyfELSQ1vEk0Q38N0Z6g8s zPWGoYpPjIHvkIdVHVY+sN7v7YURwvngoJkX5Ylzfe3KOPzdcVAzkVUHZsvf3ziahTGW+pzvG 4LPxaTbAFAp2Xymem0Xc/iIkLTBdQX5pGVu0Gdp3si0p9VI2ctBf6ZARU3ydeRJB/yu3to99/ DXxDsqSncEogJ9qVlYJrBn6tB+/1Eqxa/nM++IxIjRZVw= Hi Dhruva, Am 05.02.24 um 06:55 schrieb Dhruva Gole: > Hi, > > On Feb 04, 2024 at 23:08:49 +0100, Stefan Wahren wrote: >> Add a software PWM which toggles a GPIO from a high-resolution timer. >> >> Recent discussions in the Raspberry Pi community revealt that a lot >> of users still use MMIO userspace tools for GPIO access. One argument >> for this approach is the lack of a GPIO PWM kernel driver. So this >> series tries to fill this gap. >> >> This continues the work of Vincent Whitchurch [1], which is easier >> to read and more consequent by rejecting sleeping GPIOs than Nicola's >> approach [2]. >> >> The work has been tested on a Raspberry Pi 3 B+ and a cheap logic >> analyzer. > I recently came across this series and I have to say that it will sure b= e > a nice to have feature to be able to use any GPIO as a PWM. > > However, just a minor suggestion is that we should make sure it's well > documented how to actually use this. It would be much appreciated if you > could include some basic documentation of a few sysfs commands or any > userspace library that you used to test what you've mentioned above. i used the PWM sysfs for testing and this PWM driver doesn't change anything on this well known interface. Sorry, i don't understand what needs to be documented additionally? > > Maybe add another patch for this page? > https://docs.kernel.org/driver-api/pwm.html#using-pwms-with-the-sysfs-in= terface > > This will ensure people know about this feature and will actually be > able to use it. >