From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC317C433FE for ; Fri, 26 Nov 2021 11:08:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234089AbhKZLLx (ORCPT ); Fri, 26 Nov 2021 06:11:53 -0500 Received: from comms.puri.sm ([159.203.221.185]:38200 "EHLO comms.puri.sm" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231490AbhKZLJw (ORCPT ); Fri, 26 Nov 2021 06:09:52 -0500 Received: from localhost (localhost [127.0.0.1]) by comms.puri.sm (Postfix) with ESMTP id A2E19E1252; Fri, 26 Nov 2021 03:06:09 -0800 (PST) Received: from comms.puri.sm ([127.0.0.1]) by localhost (comms.puri.sm [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id D8m_uiIACRvh; Fri, 26 Nov 2021 03:06:08 -0800 (PST) Message-ID: <8d72c895ece6dce7d8badb241eebcbe076a03f81.camel@puri.sm> Subject: Re: [PATCH v2] media: i2c: dw9714: add optional regulator support From: Martin Kepplinger To: Sakari Ailus Cc: mchehab@kernel.org, broonie@kernel.org, kernel@puri.sm, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-pm@vger.kernel.org, Angus Ainslie Date: Fri, 26 Nov 2021 12:06:03 +0100 In-Reply-To: References: <20211126090107.1243558-1-martin.kepplinger@puri.sm> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.3-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Freitag, dem 26.11.2021 um 12:44 +0200 schrieb Sakari Ailus: > Hi Martin, > > On Fri, Nov 26, 2021 at 10:01:07AM +0100, Martin Kepplinger wrote: > > From: Angus Ainslie > > > > Allow the dw9714 to control a regulator and adjust suspend() and > > resume() > > to support both runtime and system pm. > > > > Signed-off-by: Angus Ainslie > > Signed-off-by: Martin Kepplinger > > --- > > > > revision history > > ---------------- > > > > v2: (thank you Mark) > >  * simplify the regulator_get_optional() error path > >  * fix regulator usage during probe() > > > > v1: > > https://lore.kernel.org/linux-media/20211125080922.978583-1-martin.kepplinger@puri.sm/ > > > > > > > >  drivers/media/i2c/dw9714.c | 39 > > ++++++++++++++++++++++++++++++++++++++ > >  1 file changed, 39 insertions(+) > > > > diff --git a/drivers/media/i2c/dw9714.c > > b/drivers/media/i2c/dw9714.c > > index 3863dfeb8293..e8cc19b89861 100644 > > --- a/drivers/media/i2c/dw9714.c > > +++ b/drivers/media/i2c/dw9714.c > > @@ -5,6 +5,7 @@ > >  #include > >  #include > >  #include > > +#include > >  #include > >  #include > >  #include > > @@ -36,6 +37,7 @@ struct dw9714_device { > >         struct v4l2_ctrl_handler ctrls_vcm; > >         struct v4l2_subdev sd; > >         u16 current_val; > > +       struct regulator *vcc; > >  }; > >   > >  static inline struct dw9714_device *to_dw9714_vcm(struct v4l2_ctrl > > *ctrl) > > @@ -145,6 +147,21 @@ static int dw9714_probe(struct i2c_client > > *client) > >         if (dw9714_dev == NULL) > >                 return -ENOMEM; > >   > > +       dw9714_dev->vcc = devm_regulator_get_optional(&client->dev, > > "vcc"); > > You you used regular devm_regulator_get(), you could remove the error > handling below. If there's no regulator, you'll simply get a dummy > one. ok thanks > > > +       if (IS_ERR(dw9714_dev->vcc)) { > > +               dev_dbg(&client->dev, "No vcc regulator found: > > %ld\n", > > +                       PTR_ERR(dw9714_dev->vcc)); > > +               dw9714_dev->vcc = NULL; > > +       } > > + > > +       if (dw9714_dev->vcc) { > > With (dummy) regulators, these checks become unnecessary. > > > +               rval = regulator_enable(dw9714_dev->vcc); > > +               if (rval < 0) { > > +                       dev_err(&client->dev, "failed to enable > > vcc: %d\n", rval); > > +                       return rval; > > +               } > > +       } > > + > >         v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops); > >         dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | > >                                 V4L2_SUBDEV_FL_HAS_EVENTS; > > @@ -200,6 +217,9 @@ static int __maybe_unused > > dw9714_vcm_suspend(struct device *dev) > >         struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd); > >         int ret, val; > >   > > +       if (pm_runtime_suspended(&client->dev)) > > +               return 0; > > This can't take place in a runtime PM suspend callback. You'll need > to add > system suspend callback for this. but this function is both the system and runtime suspend callback. doesn't splitting up the callbacks just add lines of code unnecessarily? > > > + > >         for (val = dw9714_dev->current_val & ~(DW9714_CTRL_STEPS - > > 1); > >              val >= 0; val -= DW9714_CTRL_STEPS) { > >                 ret = dw9714_i2c_write(client, > > @@ -208,6 +228,13 @@ static int __maybe_unused > > dw9714_vcm_suspend(struct device *dev) > >                         dev_err_once(dev, "%s I2C failure: %d", > > __func__, ret); > >                 usleep_range(DW9714_CTRL_DELAY_US, > > DW9714_CTRL_DELAY_US + 10); > >         } > > + > > +       if (dw9714_dev->vcc) { > > +               ret = regulator_disable(dw9714_dev->vcc); > > +               if (ret) > > +                       dev_err(dev, "Failed to disable vcc: %d\n", > > ret); > > +       } > > + > >         return 0; > >  } > >   > > @@ -224,6 +251,18 @@ static int  __maybe_unused > > dw9714_vcm_resume(struct device *dev) > >         struct dw9714_device *dw9714_dev = sd_to_dw9714_vcm(sd); > >         int ret, val; > >   > > +       if (pm_runtime_suspended(&client->dev)) > > Same for this one. > > > +               return 0; > > + > > +       if (dw9714_dev->vcc) { > > +               ret = regulator_enable(dw9714_dev->vcc); > > +               if (ret) { > > +                       dev_err(dev, "Failed to enable vcc: %d\n", > > ret); > > +                       return ret; > > +               } > > +               usleep_range(1000, 2000); > > +       } > > + > >         for (val = dw9714_dev->current_val % DW9714_CTRL_STEPS; > >              val < dw9714_dev->current_val + DW9714_CTRL_STEPS - 1; > >              val += DW9714_CTRL_STEPS) { >