Hi Andy,
Thanks for your reply! I have some questions want to ask you below.
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> 於 2022年7月5日 週二 清晨5:14寫道：
>
> On Mon, Jul 4, 2022 at 7:43 AM ChiaEn Wu <peterwu.pub@xxxxxxxxx> wrote:
> >
> > From: ChiaEn Wu <chiaen_wu@xxxxxxxxxxx>
> >
> > Add Mediatek MT6370 Backlight support.
>
> ...
>
> > + This driver can also be built as a module. If so the module
>
> If so,
>
> > + will be called "mt6370-backlight.ko".
>
> No ".ko" part.
>
> ...
>
> > +#include <linux/gpio/driver.h>
>
> Can you elaborate on this?
>
> > +#include <linux/kernel.h>
> > +#include <linux/log2.h>
> > +#include <linux/minmax.h>
> > +#include <linux/module.h>
>
> > +#include <linux/of.h>
>
> Can you elaborate on this?
>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
>
> Missed mod_devicetable.h.
>
> ...
>
> > + brightness_val[0] = (brightness - 1) & MT6370_BL_DIM2_MASK;
> > + brightness_val[1] = (brightness - 1)
> > + >> fls(MT6370_BL_DIM2_MASK);
>
> Bad indentation. One line?
Well... if indent to one line, it will be over 80 characters(or called columns?)
>From my understanding, it is not allowed, right??
>
> ...
>
> > + if (priv->enable_gpio)
>
> Dup check.
>
> > + gpiod_set_value(priv->enable_gpio, brightness ? 1 : 0);
>
> ...
>
> > + brightness = brightness_val[1] << fls(MT6370_BL_DIM2_MASK);
> > + brightness += (brightness_val[0] & MT6370_BL_DIM2_MASK);
>
> Too many parentheses.
>
> ...
>
> > + /*
> > + * prop_val = 1 --> 1 steps --> 0x00
> > + * prop_val = 2 ~ 4 --> 4 steps --> 0x01
> > + * prop_val = 5 ~ 16 --> 16 steps --> 0x10
> > + * prop_val = 17 ~ 64 --> 64 steps --> 0x11
> > + */
> > + prop_val = (ilog2(roundup_pow_of_two(prop_val)) + 1) >> 1;
>
> Isn't something closer to get_order() or fls()?
I will revise it to "(get_order(prop_va * PAGE_SIZE) + 1) / 2" and
this change is meet your expectations??
>
> ...
>
> > + props->max_brightness = min_t(u32, brightness,
> > + MT6370_BL_MAX_BRIGHTNESS);
>
> One line?
Ditto, it will be over 80 characters...
>
> ...
>
> > + val = 0;
>
> Do you need this here?
>
> > + prop_val = 0;
>
> Useless.
>
> > + ret = device_property_read_u8(dev, "mediatek,bled-channel-use",
> > + &prop_val);
> > + if (ret) {
> > + dev_err(dev, "mediatek,bled-channel-use DT property missing\n");
> > + return ret;
> > + }
> > +
> > + if (!prop_val || prop_val > MT6370_BL_MAX_CH) {
> > + dev_err(dev,
> > + "No channel specified or over than upper bound (%d)\n",
> > + prop_val);
> > + return -EINVAL;
> > + }
>
> ...
>
> > +static int mt6370_bl_probe(struct platform_device *pdev)
> > +{
> > + struct mt6370_priv *priv;
> > + struct backlight_properties props = {
> > + .type = BACKLIGHT_RAW,
> > + .scale = BACKLIGHT_SCALE_LINEAR,
> > + };
> > + int ret;
>
> struct device *dev = &pdev->dev;
>
> will save you a few LoCs.
>
> --
> With Best Regards,
> Andy Shevchenko
Best regards,
ChiaEn Wu
