Re: [PATCH v2 06/10] soc: Add SoC specific driver support for nuc900

Wan Zongshun
2016-07-12T09:06:10Z

On 2016年07月11日 16:03, Arnd Bergmann wrote:
> On Sunday, July 10, 2016 3:27:26 PM CEST Wan Zongshun wrote:
>> + ret = of_property_read_string(np, "compatible", &soc_dev_attr->soc_id);
>> + if (ret)
>> return -EINVAL;
>> +
>> + soc_dev_attr->machine = "NUC900EVB";
>> + soc_dev_attr->family = "NUC900";
>> + soc_dev = soc_device_register(soc_dev_attr);
>> + if (IS_ERR(soc_dev)) {
>> + kfree(soc_dev_attr);
>> + return -ENODEV;
>> + }
>> +
>> + ret = regmap_read(syscon_regmap, GCR_CHIPID, &nuc900_chipid);
>> + if (ret)
>> + return -ENODEV;
>> +
>> + device_create_file(soc_device_to_device(soc_dev), &nuc900_chipid_attr);
>> + device_create_file(soc_device_to_device(soc_dev), &nuc900_version_attr);
>> +
>> + dev_info(&pdev->dev, "Nuvoton Chip ID: 0x%x, Version ID:0x%x\n",
>> + nuc900_chipid & GCR_CHIPID_MASK,
>> + (nuc900_chipid >> 24) & 0xff);
>
> I'm still a bit unsure about the set of attributes here.
>
> - The "soc_id" is read from the device tree from the field that contains
> the board name, I think for consistency you should try to map the
> GCR_CHIPID to the name of the SoC and assign that here
>
> - The "machine" is hardcoded to "NUC900EVB", which in turn looks like
> a particular board but not the one you are running on. Maybe read
> that from the DT instead?
>
> - The "revision" is not filled at all, I would suggest using something
> derived from the GCR_CHIPID register here
>
> - you have two nonstandard attributes "chipid" and "version", which
> I'd hope to avoid -- the set of standard attributes is supposed to
> give enough information about the machine, and platform independent
> user space will never read those.

So, Maybe I can remove those two codes, no need push those information
to user space?

device_create_file(soc_device_to_device(soc_dev), &nuc900_chipid_attr);
device_create_file(soc_device_to_device(soc_dev), &nuc900_version_attr);

>
> Arnd
>
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