Re: [PATCH 2/2] regulator: rt5759: Add support for Richtek RT5759 DCDC converter

[ChiYuan Huang <u0084500@gmail.com>]

Krzysztof Kozlowski <krzk@kernel.org> 於 2022年3月25日 週五 下午8:17寫道：
>
> On 25/03/2022 02:06, cy_huang wrote:
> > From: ChiYuan Huang <cy_huang@richtek.com>
> >
> > Add support for Richtek RT5759 high-performance DCDC converter.
> >
> > Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
> > ---
> >  drivers/regulator/Kconfig            |  10 +
> >  drivers/regulator/Makefile           |   1 +
> >  drivers/regulator/rt5759-regulator.c | 372 +++++++++++++++++++++++++++++++++++
> >  3 files changed, 383 insertions(+)
> >  create mode 100644 drivers/regulator/rt5759-regulator.c
> >
>
> (...)
>
> > +static int rt5759_init_device_property(struct rt5759_priv *priv)
> > +{
> > +     unsigned int val = 0;
> > +     bool wdt_enable;
> > +
> > +     /*
> > +      * Only RT5759A support external watchdog input
> > +      */
> > +     if (priv->chip_type != CHIP_TYPE_RT5759A)
> > +             return 0;
> > +
> > +     wdt_enable = device_property_read_bool(priv->dev,
> > +                                            "richtek,watchdog-enable");
> > +     if (wdt_enable)
>
> No need for separate wdt_enable variable.
>
Ack in next.
> > +             val = RT5759A_WDTEN_MASK;
> > +
> > +     return regmap_update_bits(priv->regmap, RT5759A_REG_WDTEN,
> > +                               RT5759A_WDTEN_MASK, val);
> > +}
> > +
> > +static int rt5759_manufacturer_check(struct rt5759_priv *priv)
> > +{
> > +     unsigned int vendor;
> > +     int ret;
> > +
> > +     ret = regmap_read(priv->regmap, RT5759_REG_VENDORINFO, &vendor);
> > +     if (ret)
> > +             return ret;
> > +
> > +     if (vendor != RT5759_MANUFACTURER_ID) {
> > +             dev_err(priv->dev, "vendor info not correct (%d)\n", vendor);
> > +             return -EINVAL;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static bool rt5759_is_accessible_reg(struct device *dev, unsigned int reg)
> > +{
> > +     struct rt5759_priv *priv = dev_get_drvdata(dev);
> > +
> > +     if (reg <= RT5759_REG_DCDCSET)
> > +             return true;
> > +
> > +     if (priv->chip_type == CHIP_TYPE_RT5759A && reg == RT5759A_REG_WDTEN)
> > +             return true;
> > +
> > +     return false;
> > +}
> > +
> > +static const struct regmap_config rt5759_regmap_config = {
> > +     .reg_bits = 8,
> > +     .val_bits = 8,
> > +     .max_register = RT5759A_REG_WDTEN,
> > +     .readable_reg = rt5759_is_accessible_reg,
> > +     .writeable_reg = rt5759_is_accessible_reg,
> > +};
> > +
> > +static int rt5759_probe(struct i2c_client *i2c)
> > +{
> > +     struct rt5759_priv *priv;
> > +     int ret;
> > +
> > +     priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
> > +     if (!priv)
> > +             return -ENOMEM;
> > +
> > +     priv->dev = &i2c->dev;
> > +     priv->chip_type = (unsigned long)of_device_get_match_data(&i2c->dev);
> > +     i2c_set_clientdata(i2c, priv);
> > +
> > +     priv->regmap = devm_regmap_init_i2c(i2c, &rt5759_regmap_config);
> > +     if (IS_ERR(priv->regmap)) {
> > +             ret = PTR_ERR(priv->regmap);
> > +             dev_err(&i2c->dev, "Failed to allocate regmap (%d)\n", ret);
> > +             return ret;
> > +     }
> > +
> > +     ret = rt5759_manufacturer_check(priv);
> > +     if (ret) {
> > +             dev_err(&i2c->dev, "Failed to check device (%d)\n", ret);
> > +             return ret;
> > +     }
> > +
> > +     ret = rt5759_init_device_property(priv);
> > +     if (ret) {
> > +             dev_err(&i2c->dev, "Failed to init device (%d)\n", ret);
> > +             return ret;
> > +     }
> > +
> > +     return rt5759_regulator_register(priv);
> > +}
> > +
> > +static const struct of_device_id __maybe_unused rt5759_device_table[] = {
>
> I don't think this can be __maybe_unused. It is always referenced via
> of_match_table, isn't it?
>
I think it can declared as '__maybe_unused'.
If 'of_device_id' is unused, then in probe stage,
'of_device_get_match_data' will return NULL.
priv->chip_type will get zero as the return value. And it will be
treated as rt5759, not rt5759a.
The difference between these two are only watchdog function supported or not.

> > +     { .compatible = "richtek,rt5759", .data = (void *)CHIP_TYPE_RT5759 },
> > +     { .compatible = "richtek,rt5759a", .data = (void *)CHIP_TYPE_RT5759A },
> > +     {}
> > +};
> > +MODULE_DEVICE_TABLE(of, rt5759_device_table);
> > +
> > +static struct i2c_driver rt5759_driver = {
> > +     .driver = {
> > +             .name = "rt5759",
> > +             .of_match_table = rt5759_device_table,
> > +     },
> > +     .probe_new = rt5759_probe,
> > +};
> > +module_i2c_driver(rt5759_driver);
> > +
> > +MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
> > +MODULE_DESCRIPTION("Richtek RT5759 Regulator Driver");
> > +MODULE_LICENSE("GPL v2");
>
>
> Best regards,
> Krzysztof