Re: [PATCH 2/4] firmware: arm_scmi: bus: Bypass setting fwnode for pinctrl

[Peng Fan <peng.fan@xxxxxxxxxxx>]

On Tue, Dec 31, 2024 at 06:16:12PM +0000, Cristian Marussi wrote:
>On Fri, Dec 27, 2024 at 03:28:07PM +0000, Sudeep Holla wrote:
>> On Wed, Dec 25, 2024 at 04:20:45PM +0800, Peng Fan (OSS) wrote:
>> > From: Peng Fan <peng.fan@xxxxxxx>
>> >
>> > pinctrl-scmi.c and pinctrl-imx-scmi.c, both use SCMI_PROTOCOL_PINCTRL.
>> > If both drivers are built in, and the scmi device with name "pinctrl-imx"
>> > is created earlier, and the fwnode device points to the scmi device,
>> > non-i.MX platforms will never have the pinctrl supplier ready.
>> >
>> 
>> I wonder if we can prevent creation of "pinctrl-imx" scmi device on non
>> i.MX platforms instead of this hack which IMO is little less hackier
>> (and little more cleaner as we don't create problem and then fix here)
>> than this change.
>
>...or indeed this is another possibility

I am doing a patch as below, how to do you think?

With below patch, we could resolve the devlink issue and also support mutitple
vendor drivers built in, with each vendor driver has a machine_allowlist.

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 1d2aedfcfdb4..c1c45b545480 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -55,6 +55,20 @@ static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
        unsigned int id = 0;
        struct list_head *head, *phead = NULL;
        struct scmi_requested_dev *rdev;
+       const char * const *allowlist = id_table->machine_allowlist;
+       const char * const *blocklist = id_table->machine_blocklist;
+
+       if (blocklist && of_machine_compatible_match(blocklist)) {
+               pr_debug("block SCMI device (%s) for protocol %x\n",
+                        id_table->name, id_table->protocol_id);
+               return 0;
+       }
+
+       if (allowlist && !of_machine_compatible_match(allowlist)) {
+               pr_debug("block SCMI device (%s) for protocol %x\n",
+                        id_table->name, id_table->protocol_id);
+               return 0;
+       }

        pr_debug("Requesting SCMI device (%s) for protocol %x\n",
                 id_table->name, id_table->protocol_id);
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 688466a0e816..e1b822d3522f 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -950,6 +950,9 @@ struct scmi_device {
 struct scmi_device_id {
        u8 protocol_id;
        const char *name;
+       /* Optional */
+       const char * const *machine_blocklist;
+       const char * const *machine_allowlist;
 };

 struct scmi_driver {

Thanks,
Peng
>
>Thanks,
>Cristian