Re: [PATCH v3 1/2] leds: mt6360: Add LED driver for MT6360

From: Gene Chen
Date: Thu Sep 10 2020 - 04:11:34 EST

Andy Shevchenko <andy.shevchenko@xxxxxxxxx> 於 2020年9月9日 週三 下午9:48寫道：
>
> On Mon, Sep 7, 2020 at 1:31 PM Gene Chen <gene.chen.richtek@xxxxxxxxx> wrote:
> >
> > From: Gene Chen <gene_chen@xxxxxxxxxxx>
> >
> > Add MT6360 LED driver include 2-channel Flash LED with torch/strobe mode,
> > and 4-channel RGB LED support Register/Flash/Breath Mode
>
> I'm wondering why you don't use struct led_classdev_flash.
>
> ...
>

Both Flash and RGB LED use led_classdev_flash by
"devm_led_classdev_flash_register_ext".

> > +//
> > +// Copyright (C) 2020 MediaTek Inc.
> > +//
>
> Do you really need these two // lines?
>

ACK, I will remove it

> ...
>
> > +enum {
> > + MT6360_LED_ISNK1 = 0,
> > + MT6360_LED_ISNK2,
> > + MT6360_LED_ISNK3,
> > + MT6360_LED_ISNK4,
> > + MT6360_LED_FLASH1,
> > + MT6360_LED_FLASH2,
>
> > + MT6360_MAX_LEDS,
>
> No comma for terminator entry.
>

ACK

> > +};
>
> ...
>
> > +#define MT6360_ISNK_MASK 0x1F
>
> GENMASK()
>
> ...
>
> > +#define MT6360_ITORCH_MIN 25000
> > +#define MT6360_ITORCH_STEP 12500
> > +#define MT6360_ITORCH_MAX 400000
> > +#define MT6360_ISTRB_MIN 50000
> > +#define MT6360_ISTRB_STEP 12500
> > +#define MT6360_ISTRB_MAX 1500000
> > +#define MT6360_STRBTO_MIN 64000
> > +#define MT6360_STRBTO_STEP 32000
> > +#define MT6360_STRBTO_MAX 2432000
>
> Add unit suffixes, please.
>

ACK

> ...
>
> > +#define FLED_TORCH_FLAG_MASK 0x0c
>
> > +#define FLED_STROBE_FLAG_MASK 0x03
>
> GENMASK()
>

ACK

> ...
>
> > + dev_dbg(lcdev->dev, "[%d] brightness %d\n", led->led_no, level);
>
> Not production noise.
>

ACK

> ...
>
> > + ret = regmap_update_bits(priv->regmap, MT6360_REG_RGBEN, enable_mask, val);
> > + if (ret)
> > + return ret;
> > +
> > + return 0;
>
> return regmap...
>
> > + u32 val = (level) ? MT6360_FLCSEN_MASK(led->led_no) : 0;
>
> Why parens?
>

ACK

> ...
>
> > + dev_dbg(lcdev->dev, "[%d] brightness %d\n", led->led_no, level);
>
> Noise.
>

ACK

> ...
>
> > + if (priv->fled_strobe_used) {
> > + dev_warn(lcdev->dev, "Please disable strobe first [%d]\n", priv->fled_strobe_used);
> > + return -EINVAL;
>
> Hmm... Shouldn't be guaranteed by some framework?
>

Because both Flash LED use single logically control.
It doesn't exist one LED is torch mode, and the other is strobe mode.

> ...
>
> > + curr = prev & (~BIT(led->led_no));
>
> Too many parens.
>

ACK

> ...
>
> > +static int mt6360_strobe_brightness_set(struct led_classdev_flash *fl_cdev, u32 brightness)
> > +{
> > + struct mt6360_led *led = container_of(fl_cdev, struct mt6360_led, flash);
> > + struct led_classdev *lcdev = &fl_cdev->led_cdev;
> > +
>
> > + dev_dbg(lcdev->dev, "[%d] strobe brightness %d\n", led->led_no, brightness);
>
> Noise. Point of this entire function?
>

ACK, I will remove it, reserve function entry only for register
ledcass_dev check ops exist

> > + return 0;
> > +}
>
> ...
>
> > + dev_dbg(lcdev->dev, "[%d] strobe state %d\n", led->led_no, state);
>
> Noise.
>
> If you wish to do it right, add trace events to the framework.
>

ACK, I will remove it.

> ...
>
> > + if (priv->fled_torch_used) {
>
> > + dev_warn(lcdev->dev, "Please disable torch first [0x%x]\n", priv->fled_torch_used);
>
> Again, why the warning? Can this be a part of the framework?
>

Same as above.

> > + return -EINVAL;
> > + }
>
> ...
>
> > + curr = prev & (~BIT(led->led_no));
>
> Too many parens.
>

ACK

> ...
>
> > + if (!prev && curr)
> > + usleep_range(5000, 6000);
> > + else if (prev && !curr)
> > + udelay(500);
>
> These delays must be explained.
>

ACK

> ...
>
> > + if (led->led_no == MT6360_LED_FLASH1) {
> > + strobe_timeout_mask = MT6360_FLED1STRBTO_MASK;
> > + fled_short_mask = MT6360_FLED1SHORT_MASK;
>
> > +
>
> Redundant blank line.
>

ACK

> > + } else {
> > + strobe_timeout_mask = MT6360_FLED2STRBTO_MASK;
> > + fled_short_mask = MT6360_FLED2SHORT_MASK;
> > + }
>
> ...
>
> > +static int mt6360_flash_external_strobe_set(struct v4l2_flash *v4l2_flash, bool enable)
> > +{
> > + struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
> > + struct mt6360_led *led = container_of(flash, struct mt6360_led, flash);
> > + struct mt6360_priv *priv = led->priv;
>
> > + u32 enable_mask = MT6360_FLCSEN_MASK(led->led_no);
>
> enable_mask -> mask
> u32 value = enable ? mask : 0;
>
> > + int ret;
> > +
> > + ret = regmap_update_bits(priv->regmap, MT6360_REG_FLEDEN, enable_mask,
>
> > + enable ? enable_mask : 0);
>
> ret = ... mask, value);
>

ACK

> > + if (ret)
> > + return ret;
> > +
> > + if (enable)
> > + priv->fled_strobe_used |= BIT(led->led_no);
> > + else
> > + priv->fled_strobe_used &= (~BIT(led->led_no));
>
> Too many parens.
>

ACK

> > +
> > + return 0;
> > +}
>
> ...
>
> > + s->val = s->max = (s->min) + (lcdev->max_brightness - 1) * s->step;
>
> Ditto.
>

ACK

> ...
>
> > +static void clamp_align(u32 *v, u32 min, u32 max, u32 step)
>
> Can we keep a similar API, i.e. return a new value rather than update old?
>
> > +{
>
> > + *v = clamp_val(*v, min, max);
>
> I would rather use a temporary variable (and it actually will be
> required with above).
>
> > + if (step > 1)
> > + *v = (*v - min) / step * step + min;
>
> Sounds like open coded rounddown().
>

ACK

> > +}
>
> ...
>
> > + lcdev->max_brightness = (val - MT6360_ITORCH_MIN) / MT6360_ITORCH_STEP + 1;
>
> DIV_ROUND_UP(val - MT6360_ITORCH_MIN, MT6360_ITORCH_STEP) ?
>

This is mapping 0~val to 1~max_brightness as level.
I convert val below MT6360_ITORCH_STEP to 1 for ignore max_brightness
= 0, because 0 means disable.
There is a little difference from DIV_ROUND_UP.

> ...
>
> > +static int mt6360_init_common_properties(struct mt6360_led *led, struct led_init_data *init_data)
> > +{
> > + const char *str;
> > +
> > + if (!fwnode_property_read_string(init_data->fwnode, "default-state", &str)) {
> > + if (!strcmp(str, "on"))
> > + led->default_state = STATE_ON;
> > + else if (!strcmp(str, "keep"))
> > + led->default_state = STATE_KEEP;
>
> > + else
>
> I wouldn't allow some garbage to be off.
>

ACK

> > + led->default_state = STATE_OFF;
> > + }
>
> What about
>
> static const char * const states = { "on", "keep", "off" };
>
> int ret;
>
> ret = match_string(states, ARRAY_SIZE(states), str);
> if (ret)
> ...
>
> default_state = ret;
>
> ?
>
> > + return 0;
> > +}
>

ACK

> ...
>
> > +static int mt6360_led_probe(struct platform_device *pdev)
> > +{
> > + struct mt6360_priv *priv;
> > + struct fwnode_handle *child;
> > + int i, ret;
> > +
>
> > + priv->regmap = dev_get_regmap(pdev->dev.parent, NULL);
> > + if (!priv->regmap) {
> > + dev_err(&pdev->dev, "Failed to get parent regmap\n");
> > + return -ENODEV;
> > + }
>
> ...
>
> > +out:
>
> out_flash_leds_release: ?
>

ACK

> > + for (i = MT6360_LED_FLASH1; i <= MT6360_LED_FLASH2; i++) {
> > + struct mt6360_led *led = priv->leds[i];
> > +
> > + if (led && led->v4l2_flash)
> > + v4l2_flash_release(led->v4l2_flash);
> > +
> > + }
>
> ...
>
> > +static int mt6360_led_remove(struct platform_device *pdev)
> > +{
> > + struct mt6360_priv *priv = platform_get_drvdata(pdev);
> > + int i;
> > +
> > + for (i = MT6360_LED_FLASH1; i <= MT6360_LED_FLASH2; i++) {
> > + struct mt6360_led *led = priv->leds[i];
> > +
> > + if (led && led->v4l2_flash)
> > + v4l2_flash_release(led->v4l2_flash);
> > +
> > + }
>
> Looks like a code duplication.
>

ACK

> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id __maybe_unused mt6360_led_of_id[] = {
> > + { .compatible = "mediatek,mt6360-led", },
>
> > + {},
>
> No need comma.
>

ACK

> > +};
>
>
> --
> With Best Regards,
> Andy Shevchenko