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

From: Wan Zongshun
Date: Tue Jul 12 2016 - 05:06:27 EST




On 2016å07æ11æ 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

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel