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From:   szuni chen <szunichen@gmail.com>
Date:   Thu, 7 Jul 2022 18:49:26 +0800
Message-ID: <CA+hk2fbm8ppKecVJL6D9rYJizf9baV8mOmwRx6GyO+MKvJ3xBQ@mail.gmail.com>
Subject: Re: [PATCH v4 12/13] leds: flashlight: mt6370: Add Mediatek MT6370
 flashlight support
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     ChiaEn Wu <peterwu.pub@gmail.com>,
        Lee Jones <lee.jones@linaro.org>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        Jingoo Han <jingoohan1@gmail.com>, Pavel Machek <pavel@ucw.cz>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Sebastian Reichel <sre@kernel.org>,
        Chunfeng Yun <chunfeng.yun@mediatek.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Guenter Roeck <linux@roeck-us.net>,
        "Krogerus, Heikki" <heikki.krogerus@linux.intel.com>,
        Helge Deller <deller@gmx.de>,
        ChiaEn Wu <chiaen_wu@richtek.com>,
        Alice Chen <alice_chen@richtek.com>,
        cy_huang <cy_huang@richtek.com>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Linux LED Subsystem <linux-leds@vger.kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        USB <linux-usb@vger.kernel.org>,
        linux-iio <linux-iio@vger.kernel.org>,
        "open list:FRAMEBUFFER LAYER" <linux-fbdev@vger.kernel.org>
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Hi Andy,

Thank you for the valuable comment.

Andy Shevchenko <andy.shevchenko@gmail.com> =E6=96=BC 2022=E5=B9=B47=E6=9C=
=885=E6=97=A5 =E9=80=B1=E4=BA=8C =E6=B8=85=E6=99=A85:06=E5=AF=AB=E9=81=93=
=EF=BC=9A
>
> On Mon, Jul 4, 2022 at 7:43 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote:
>
> > Add Mediatek MT6370 flashlight support.
>
> ...
>
> > +         This driver can also be built as a module. If so the module
>
> If so,
>
Thank you, I'll fix it in the next version.

> > +         will be called "leds-mt6370-flash.ko".
>
> No ".ko" part.
>
Thank you, I'll fix it in the next version.

> ...
>
> > +#define MT6370_ITORCH_MINUA            25000
> > +#define MT6370_ITORCH_STEPUA           12500
> > +#define MT6370_ITORCH_MAXUA            400000
> > +#define MT6370_ITORCH_DOUBLE_MAXUA     800000
> > +#define MT6370_ISTRB_MINUA             50000
> > +#define MT6370_ISTRB_STEPUA            12500
> > +#define MT6370_ISTRB_MAXUA             1500000
> > +#define MT6370_ISTRB_DOUBLE_MAXUA      3000000
> > +#define MT6370_STRBTO_MINUS            64000
> > +#define MT6370_STRBTO_STEPUS           32000
> > +#define MT6370_STRBTO_MAXUS            2432000
>
> Make units suffix visible, i.e. _US, _uA, etc.
>
Thank you, I'll fix it in the next version.

> ...
>
> > +       if (curr)
> > +               val |=3D MT6370_TORCHEN_MASK;
> > +
> > +
>
> One blank line is enough.
>
Thank you, I'll fix it in the next version.

> ...
>
> > +       /*
> > +        * Due to the current spike when turning on flash,
> > +        * let brightness to be kept by framework.
>
> brightness be
> the framework
>
Thank you, I'll fix it in the next version.

> > +        * This empty function is used to
> > +        * prevent led_classdev_flash register ops check failure.
> > +        */
>
Thank you, I'll fix it in the next version.
> ...
>
> > +       } else {
> > +               ret =3D regmap_update_bits(priv->regmap,
> > +                                        MT6370_REG_FLEDISTRB(led->led_=
no),
> > +                                        MT6370_ISTROBE_MASK, val);
>
> > +               if (ret)
> > +                       return ret;
>
> Dup of the below.
>
Thank you, I'll fix it in the next version.

> > +       }
> > +       return ret;
>
> ...
>
> > +       /*
> > +        * If the flash need to be on,
> > +        * config the flash current ramping up to the setting value
> > +        * Else, always recover back to the minimum one
>
> Missed periods.
>
Thank you, I'll fix it in the next version.

> > +        */
>
> ...
>
> > +       /*
> > +        * For the flash turn on/off, HW ramping up/down time is 5ms/50=
0us
> > +        * respectively.
> > +        */
> > +       if (!prev && curr)
> > +               usleep_range(5000, 6000);
> > +       else if (prev && !curr)
> > +               udelay(500);
>
> Comment doesn't explain why this is suddenly a busy loop operation?
>
For the flash turn on/off, HW ramping up/down waiting time is
5ms/500us, respectively.
The busy loop is for preventing turn on/off in wait time, which will
cause unexpected problems.

If I change the comment to
"For the flash turn on/off, HW ramping up/down waiting time is
5ms/500us, respectively.
Need to wait until HW ramping successfully to prevent the unexpected proble=
m.",
will this meet your expectation?

>
> > +static int mt6370_led_register(struct device *parent, struct mt6370_le=
d *led,
> > +                               struct led_init_data *init_data)
> > +{
> > +       struct v4l2_flash_config v4l2_config =3D {0};
> > +       int ret;
> > +
> > +       ret =3D devm_led_classdev_flash_register_ext(parent, &led->flas=
h,
> > +                                                  init_data);
> > +       if (ret) {
> > +               dev_err(parent, "Couldn't register flash %d\n", led->le=
d_no);
> > +               return ret;
> > +       }
> > +
> > +       mt6370_init_v4l2_flash_config(led, &v4l2_config);
> > +       led->v4l2_flash =3D v4l2_flash_init(parent, init_data->fwnode,
> > +                                         &led->flash, &v4l2_flash_ops,
> > +                                         &v4l2_config);
> > +       if (IS_ERR(led->v4l2_flash)) {
> > +               dev_err(parent, "Failed to register %d v4l2 sd\n", led-=
>led_no);
> > +               return PTR_ERR(led->v4l2_flash);
> > +       }
> > +
> > +       return 0;
> > +}
>
> ...
>
> > +       } else
> > +               val =3D clamp_align(val, MT6370_STRBTO_MINUS, MT6370_ST=
RBTO_MAXUS,
> > +                                 MT6370_STRBTO_STEPUS);
>
> Missed {}
>
Thank you, I'll fix it in the next version.

> > +
> > +
>
> One blank line is enough.
>
Thank you, I'll fix it in the next version.

> --

Yours Sincerely,
Alice