[PATCH 7/8] firmware: arm_scmi: transport: Add ACPI PCC transport

[Dan Carpenter]

On Fri, Oct 17, 2025 at 02:23:50PM +0100, Sudeep Holla wrote:
> +static int pcc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
> +			  bool tx)
> +{
> +	const char *desc = tx ? "Tx" : "Rx";
> +	struct device *cdev = cinfo->dev;
> +	struct scmi_pcc *smbox;
> +	int ret, ss_id;
> +	struct mbox_client *cl;
> +
> +	smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL);
> +	if (!smbox)
> +		return -ENOMEM;
> +
> +	cl = &smbox->cl;
> +	cl->dev = cdev;
> +	cl->tx_prepare = tx ? tx_prepare : NULL;
> +	cl->rx_callback = rx_callback;
> +	cl->tx_block = false;
> +
> +	ss_id = pcc_get_ss_id(cinfo->id, tx);
> +	if (ss_id < 0)
> +		return ss_id;
> +
> +	smbox->pchan = pcc_mbox_request_channel(cl, ss_id);
> +	if (IS_ERR(smbox->pchan)) {
> +		ret = PTR_ERR(smbox->pchan);
> +		if (ret != -EPROBE_DEFER)
> +			dev_err(cdev,
> +				"failed to request SCMI %s mailbox\n", desc);
> +		return ret;
> +	}

Use the dev_err_probe() function for this:

	smbox->pchan = pcc_mbox_request_channel(cl, ss_id);
	if (IS_ERR(smbox->pchan)
		return dev_err_probe(cdev, PTR_ERR(smbox->pchan),
				     "failed to request SCMI %s mailbox\n",
				     desc);

regards,
dan carpenter

> +
> +	cinfo->transport_info = smbox;
> +	smbox->cinfo = cinfo;
> +
> +	return 0;
> +}