remoteproc: imx_dsp_rproc: Convert to dev_pm_domain_attach|detach_list()

Let's avoid the boilerplate code to manage the multiple PM domain case, by
converting into using dev_pm_domain_attach|detach_list().

Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Daniel Baluta <daniel.baluta@nxp.com>
Cc: <linux-remoteproc@vger.kernel.org>
Tested-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Reviewed-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20240130123951.236243-3-ulf.hansson@linaro.org

Author: Ulf Hansson

drivers/remoteproc/imx_dsp_rproc.c

@@ -103,12 +103,10 @@ enum imx_dsp_rp_mbox_messages {
  * @tx_ch: mailbox tx channel handle
  * @rx_ch: mailbox rx channel handle
  * @rxdb_ch: mailbox rx doorbell channel handle
- * @pd_dev: power domain device
- * @pd_dev_link: power domain device link
+ * @pd_list: power domain list
  * @ipc_handle: System Control Unit ipc handle
  * @rproc_work: work for processing virtio interrupts
  * @pm_comp: completion primitive to sync for suspend response
- * @num_domains: power domain number
  * @flags: control flags
  */
 struct imx_dsp_rproc {
@@ -121,12 +119,10 @@ struct imx_dsp_rproc {
 	struct mbox_chan			*tx_ch;
 	struct mbox_chan			*rx_ch;
 	struct mbox_chan			*rxdb_ch;
-	struct device				**pd_dev;
-	struct device_link			**pd_dev_link;
+	struct dev_pm_domain_list		*pd_list;
 	struct imx_sc_ipc			*ipc_handle;
 	struct work_struct			rproc_work;
 	struct completion			pm_comp;
-	int					num_domains;
 	u32					flags;
 };
 
@@ -955,74 +951,14 @@ static const struct rproc_ops imx_dsp_rproc_ops = {
 static int imx_dsp_attach_pm_domains(struct imx_dsp_rproc *priv)
 {
 	struct device *dev = priv->rproc->dev.parent;
-	int ret, i;
-
-	priv->num_domains = of_count_phandle_with_args(dev->of_node,
-						       "power-domains",
-						       "#power-domain-cells");
-
-	/* If only one domain, then no need to link the device */
-	if (priv->num_domains <= 1)
-		return 0;
-
-	priv->pd_dev = devm_kmalloc_array(dev, priv->num_domains,
-					  sizeof(*priv->pd_dev),
-					  GFP_KERNEL);
-	if (!priv->pd_dev)
-		return -ENOMEM;
-
-	priv->pd_dev_link = devm_kmalloc_array(dev, priv->num_domains,
-					       sizeof(*priv->pd_dev_link),
-					       GFP_KERNEL);
-	if (!priv->pd_dev_link)
-		return -ENOMEM;
-
-	for (i = 0; i < priv->num_domains; i++) {
-		priv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
-		if (IS_ERR(priv->pd_dev[i])) {
-			ret = PTR_ERR(priv->pd_dev[i]);
-			goto detach_pm;
-		}
-
-		/*
-		 * device_link_add will check priv->pd_dev[i], if it is
-		 * NULL, then will break.
-		 */
-		priv->pd_dev_link[i] = device_link_add(dev,
-						       priv->pd_dev[i],
-						       DL_FLAG_STATELESS |
-						       DL_FLAG_PM_RUNTIME);
-		if (!priv->pd_dev_link[i]) {
-			dev_pm_domain_detach(priv->pd_dev[i], false);
-			ret = -EINVAL;
-			goto detach_pm;
-		}
-	}
-
-	return 0;
-
-detach_pm:
-	while (--i >= 0) {
-		device_link_del(priv->pd_dev_link[i]);
-		dev_pm_domain_detach(priv->pd_dev[i], false);
-	}
-
-	return ret;
-}
-
-static int imx_dsp_detach_pm_domains(struct imx_dsp_rproc *priv)
-{
-	int i;
+	int ret;
 
-	if (priv->num_domains <= 1)
+	/* A single PM domain is already attached. */
+	if (dev->pm_domain)
 		return 0;
 
-	for (i = 0; i < priv->num_domains; i++) {
-		device_link_del(priv->pd_dev_link[i]);
-		dev_pm_domain_detach(priv->pd_dev[i], false);
-	}
-
-	return 0;
+	ret = dev_pm_domain_attach_list(dev, NULL, &priv->pd_list);
+	return ret < 0 ? ret : 0;
 }
 
 /**
@@ -1154,7 +1090,7 @@ static int imx_dsp_rproc_probe(struct platform_device *pdev)
 	return 0;
 
 err_detach_domains:
-	imx_dsp_detach_pm_domains(priv);
+	dev_pm_domain_detach_list(priv->pd_list);
 err_put_rproc:
 	rproc_free(rproc);
 
@@ -1168,7 +1104,7 @@ static void imx_dsp_rproc_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 	rproc_del(rproc);
-	imx_dsp_detach_pm_domains(priv);
+	dev_pm_domain_detach_list(priv->pd_list);
 	rproc_free(rproc);
 }