From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.andi.de1.cc (mail.andi.de1.cc [178.238.236.174]) (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 EA0B928F4; Wed, 24 Sep 2025 20:40:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.238.236.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758746445; cv=none; b=XvVHt9yWUaw9UlcuDNNmcwyAevCyBHnrsU87zrwMyxG1rfS1xTEtI6QTX7E44PKBOFU8tTX/IzKfMI+hxWebqUIDTUn1oIkwDE2a3A5ETAusqjUIX4STP+MIGMewKD7NhDXppI4lgoTgFi5eVkJVeXV9QtI5hYfzrxrr+hf5QW0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758746445; c=relaxed/simple; bh=QTIQkpV/ciuM/sLyZDPrsBTzQxcBE89VDpwEWGscX4g=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=W/u5s1H3G4lNMbMhhWRxGtGeCZkpu/yjUX8ZT8WCPkB4GkjTJYjIih8DnHCMcojuRfdhC0uV3kjCl/pbDWqN6n4dFvBXQQRVxwh+hz7Q4lMEhOok7KjlIj8S+cGJfumx3I4ePHOcvdLS1E34U6gCwt5fo5YW6dC0MpXEx87Dbs0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kemnade.info; spf=pass smtp.mailfrom=kemnade.info; dkim=pass (2048-bit key) header.d=kemnade.info header.i=@kemnade.info header.b=8EouNj5t; arc=none smtp.client-ip=178.238.236.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kemnade.info Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kemnade.info Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kemnade.info header.i=@kemnade.info header.b="8EouNj5t" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kemnade.info; s=20220719; h=References:In-Reply-To:Cc:From:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID; bh=ITB1rCZb/1p8Dc/cYBEMMSkfLogfsT+JzDlWdMz+ne4=; b=8EouNj5t5a/wVV06FrfHRkcTwE 3fCUlq29rCQLw3onGQP+cEJYbeShna8XxxtQOCfAEsQHrl+04HQONofxi2851Jf4kpmPpR9ye/aqK xFGE2sExRGKAJJ7us7Y/61S9Tmrqmk21X2e0jRzmwvu8hDgkGgmAN+Blcjhbz1apYQ3en17X+fNwJ Zy1/7zDI5qu6VF9ElRhahDa8edqWa3G8AriQ6WCbWSnmtV+yU4knF5wwLl7mCVK5Uk7WDnYc5SP3Y nY7QSPOSIGDsIu0ZpaLFeGLLEUncYMM5gz4qwJ4Gh/8uxtIFNpw6G+Meg4j7OefoM5Cq6RncsETd+ rRHkFUKg==; Date: Wed, 24 Sep 2025 22:40:35 +0200 From: Andreas Kemnade To: Guenter Roeck Cc: jdelvare@suse.com, lgirdwood@gmail.com, broonie@kernel.org, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, Alistair Francis Subject: Re: [PATCH 2/2] hwmon: (sy7636a) enable regulator only if needed Message-ID: <20250924224035.2b20459a@kemnade.info> In-Reply-To: <25ef8eef-a4e6-436b-87cd-c77506b4b215@roeck-us.net> References: <20250920114311.291450-1-andreas@kemnade.info> <20250920114311.291450-3-andreas@kemnade.info> <25ef8eef-a4e6-436b-87cd-c77506b4b215@roeck-us.net> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; aarch64-unknown-linux-gnu) Precedence: bulk X-Mailing-List: linux-hwmon@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 24 Sep 2025 09:06:15 -0700 Guenter Roeck wrote: > On Sat, Sep 20, 2025 at 01:43:11PM +0200, Andreas Kemnade wrote: > > Avoid having all the regulators in the SY7636A enabled all the time > > to significantly reduce current consumption. In pratical scenarios, > > the regulators are only needed when a refresh is done on the epaper > > display powered by the SY7636A. This is can save around 10mA which > > is much for this kind of devices. > > Also fixes the asymmetrical single enable call. > > > > Signed-off-by: Andreas Kemnade > > --- > > drivers/hwmon/sy7636a-hwmon.c | 34 ++++++++++++++++++++++++---------- > > 1 file changed, 24 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/hwmon/sy7636a-hwmon.c b/drivers/hwmon/sy7636a-hwmon.c > > index e83d0e50c735..0fda69bea3b4 100644 > > --- a/drivers/hwmon/sy7636a-hwmon.c > > +++ b/drivers/hwmon/sy7636a-hwmon.c > > @@ -18,14 +18,26 @@ > > > > #include > > > > +struct sy7636a_hwmon_data { > > + struct regmap *regmap; > > + struct regulator *regulator; > > +}; > > + > > + > > static int sy7636a_read(struct device *dev, enum hwmon_sensor_types type, > > u32 attr, int channel, long *temp) > > { > > - struct regmap *regmap = dev_get_drvdata(dev); > > + struct sy7636a_hwmon_data *drvdata = dev_get_drvdata(dev); > > int ret, reg_val; > > > > - ret = regmap_read(regmap, > > + ret = regulator_enable(drvdata->regulator); > > + if (ret) > > + return ret; > > + > > + ret = regmap_read(drvdata->regmap, > > SY7636A_REG_TERMISTOR_READOUT, ®_val); > > Does that really work without delay ? Usually it takes some time for a chip > to return useful data after its power supply has been enabled. calls > Hmm, enabling the onoff bit behind the regulator is just needed to turn ADC on here. But there is also the power good wait which should usually be enough. Usually... But there is no guarantee. So yes, better wait for one adc aquisition. Regards, Andreas