How to add I3C device node for devices with random PID[31:0]

From: Steven Niu <steven.niu.uj@renesas.com>
To: "alexandre.belloni@bootlin.com" <alexandre.belloni@bootlin.com>
Cc: "linux-i3c@lists.infradead.org" <linux-i3c@lists.infradead.org>,
	Steven Niu <steven.niu.uj@renesas.com>
Subject: How to add I3C device node for devices with random PID[31:0]
Date: Tue, 12 Mar 2024 11:30:30 +0000	[thread overview]
Message-ID: <OSAPR01MB4323733A7B1678DE5B8C3027BA2B2@OSAPR01MB4323.jpnprd01.prod.outlook.com> (raw)

Hi, Alexandre,

There is a class if I3C device with random value in PID[31:0] and these devices
are identified with PID[32]=1.

In function of_i3c_master_add_i3c_boardinfo(), the node for i3c device with
random PID is denied to be added to baordinfo with code below:

>  if ((boardinfo->pid & GENMASK_ULL(63, 48)) ||
>         I3C_PID_RND_LOWER_32BITS(boardinfo->pid))
>  return -EINVAL;

According i3c.yaml, an I3C device is allowed to attach extra resources by
adding node in devicetree. I have some questions:
1. Why the I3C devices with random PID are excluded here?
2. How to attach extra resources to such kind of devices?
3. Could 'I3C_PID_RND_LOWER_32BITS(boardinfo->pid)' be removed to allow adding
   the node of i3c devices with random PID to i3c boardinfo list?

Thank you.

Regards,
Steven

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