Re: [PATCH v3 2/2] gpio: loongson: add firmware offset parse support

[Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>]

Hi andy,

Sorry, I lost this email due to issues with my company's email server. I
will adopt your suggestion in v5 version.

在 2023/8/15 上午5:48, andy.shevchenko@xxxxxxxxx 写道:
> Mon, Aug 07, 2023 at 03:40:43PM +0800, Yinbo Zhu kirjoitti:
> > Loongson GPIO controllers come in multiple variants that are compatible
> > except for certain register offset values.  Add support for device
> > properties allowing to specify them in ACPI or DT.
>
> > +	if (device_property_read_u32(dev, "ngpios", &ngpios) || !ngpios)
> > +		return -EINVAL;
> > +
> > +	ret = DIV_ROUND_UP(ngpios, 8);
> > +	switch (ret) {
> > +	case 1 ... 2:
> > +		io_width = ret;
> > +		break;
> > +	case 3 ... 4:
> > +		io_width = 0x4;
> > +		break;
> > +	case 5 ... 8:
> > +		io_width = 0x8;
> > +		break;
> > +	default:
> > +		dev_err(dev, "unsupported io width\n");
> > +		return -EINVAL;
> > +	}
>
> Why? We have bgpio_init() handle this.
> https://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git/commit/?h=gpio/for-next&id=55b2395e4e92adc492c6b30ac109eb78250dcd9d


okay, I got it.

> ...
>
> > +	lgpio->chip.can_sleep = 0;
>
> It's boolean, use boolean initializer.


okay, I got it.

> ...
>
> > +	if (lgpio->chip_data->label)
> > +		lgpio->chip.label = lgpio->chip_data->label;
> > +	else
> > +		lgpio->chip.label = kstrdup(to_platform_device(dev)->name, GFP_KERNEL);
>
> No error check? Not a devm_*() variant, so leaking memory?


This code had been removed in v4.

> ...
>
> > +	{
> > +		.id = "LOON0007",
> > +	},
>
> How does DSDT excerpt for this device look like?


LOON0007 and LOON000A are similar, LOON000A is for 2k2000 gpio0.

     Device (GPO0)
        {
            Name (_HID, "LOON000A")  // _HID: Hardware ID
            Name (_ADR, Zero)  // _ADR: Address
            Name (_UID, One)  // _UID: Unique ID
            Name (_CRS, ResourceTemplate ()  // _CRS: Current Resource 
Settings
            {
                QWordMemory (ResourceConsumer, PosDecode, MinFixed, 
MaxFixed, NonCacheable, ReadWrite,
                    0x0000000000000000, // Granularity
                    0x000000001FE00500, // Range Minimum
                    0x000000001FE00520, // Range Maximum
                    0x0000000000000000, // Translation Offset
                    0x0000000000000021, // Length
                    ,, , AddressRangeMemory, TypeStatic)
            })
            Name (_DSD, Package (0x02)  // _DSD: Device-Specific Data
            {
                ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301") /* 
Device Properties for _DSD */,
                Package (0x01)
                {
                    Package (0x02)
                    {
                        "ngpios",
                        0x20
                    }
                }
            })
        }


Thanks,
Yinbo